Sample records for primary driving force

  1. Assessment: A Driving Force.

    Rakow, Steven J.


    Asserts that educational assessment drives the curriculum. Thus, assessment is very important in contemplating reform in science education. Assessment should be an integral part of the instructional process, utilizing diagnostic testing, monitoring, and summative evaluations. (PR)

  2. Technology as a driving force

    Torvund, T. [Norsk Hydro A/S (Norway)


    The competitiveness of the Norwegian Continental shelf has been put firmly on the agenda in Norway since the report from a working group set up by the Ministry of Industry and Energy was released in February this year. If there is to be secured a long future for oil and gas activities, a reduction in the time and costs used in the projects of the order of 40-50%, without jeopardizing the high safety and environmental standards achieved in Norway. The paper addresses how technology can be a driving force in achieving these aims. But technology alone cannot do the job. Progress and changes in several other areas are also necessary, and the new scenario also calls for improved relations between all actors in the North Sea, authorities, oil companies, contractors and labour unions. 15 figs.

  3. Chemical driving force for rafting in superalloys

    Nabarro, FRN


    Full Text Available The author provides a brief overview of the chemical driving forces for rafting in superalloys. Until recently, all theories of the driving force for rafting have considered the compositions of the two phases to be fixed, although accepting...

  4. Forces driving epithelial wound healing

    Brugués, Agustí; Anon, Ester; Conte, Vito; Veldhuis, Jim H.; Gupta, Mukund; Colombelli, Julien; Muñoz, José J.; Brodland, G. Wayne; Ladoux, Benoit; Trepat, Xavier


    A fundamental feature of multicellular organisms is their ability to self-repair wounds through the movement of epithelial cells into the damaged area. This collective cellular movement is commonly attributed to a combination of cell crawling and `purse-string’ contraction of a supracellular actomyosin ring. Here we show by direct experimental measurement that these two mechanisms are insufficient to explain force patterns observed during wound closure. At early stages of the process, leading actin protrusions generate traction forces that point away from the wound, showing that wound closure is initially driven by cell crawling. At later stages, we observed unanticipated patterns of traction forces pointing towards the wound. Such patterns have strong force components that are both radial and tangential to the wound. We show that these force components arise from tensions transmitted by a heterogeneous actomyosin ring to the underlying substrate through focal adhesions. The structural and mechanical organization reported here provides cells with a mechanism to close the wound by cooperatively compressing the underlying substrate.

  5. Thermodynamic driving force for rafting in superalloys

    Nabarro, FRN


    Full Text Available Eshelby’s energy-momentum tensor is used to provide an analytical expression for the driving force for rafting in the elastic regime in a super alloy with a high volume fraction of gamma'. The structure is modeled as a simple cubic array of gamma...

  6. Forces driving epithelial spreading in zebrafish gastrulation.

    Behrndt, Martin; Salbreux, Guillaume; Campinho, Pedro; Hauschild, Robert; Oswald, Felix; Roensch, Julia; Grill, Stephan W; Heisenberg, Carl-Philipp


    Contractile actomyosin rings drive various fundamental morphogenetic processes ranging from cytokinesis to wound healing. Actomyosin rings are generally thought to function by circumferential contraction. Here, we show that the spreading of the enveloping cell layer (EVL) over the yolk cell during zebrafish gastrulation is driven by a contractile actomyosin ring. In contrast to previous suggestions, we find that this ring functions not only by circumferential contraction but also by a flow-friction mechanism. This generates a pulling force through resistance against retrograde actomyosin flow. EVL spreading proceeds normally in situations where circumferential contraction is unproductive, indicating that the flow-friction mechanism is sufficient. Thus, actomyosin rings can function in epithelial morphogenesis through a combination of cable-constriction and flow-friction mechanisms.

  7. Driving forces in the Greenlandic urbanization

    Hendriksen, Kåre


    Generally urbanization is recognised as a natural development where the population is mowing into the larger towns driven by e.g. better job opportunities, larger product and service supply and better education and health services, and it is often argued that this is also the driving forces...... for accelerating changes in the Greenlandic settlement pattern. Resent research problematize to what extent this logic is so simple? Also in Greenland, with its 56.000 inhabitants spread over 17 so-called towns and 58 settlements, there is a clear correlation between settlement pattern and job opportunities....... This centralization has left geographical regions with limited livelihood and at the same time a lack of utilization of local resources and trade opportunities. Additionally the Greenlandic so called larger cities are ended in an un-sustainable economical situation manly depending on public financed jobs or social...

  8. Global Plate Driving Forces at 50Ma

    Butterworth, N. P.; Quevedo, L. E.; Müller, R. D.


    We apply a novel workflow utilising the BEM-Earth geodynamic software to analyse the global coupled plate-mantle dynamics at 50 Ma. A subduction history model based on kinematic data going as far back as 80 Ma was developed using the GPlates software. Advection of the plates into the mantle takes into account the absolute plate motions and lithospheric thickness derived from its age to produce an estimated density heterogeneity initial model condition in the upper mantle. The resulting global model consists of regions of a mantle viscosity and density structure that is post-processed to ensure smooth non-overlapping 3D surfaces. BEM-Earth is then free to evolve the model toward the 50 Ma solution. The evolution of the model is driven by self-consistent buoyancy driven mantle dynamics. We use the model velocity output to quantify changes in forces driving the plates before and after 50 Ma. We analyse the rapid change in plate motion of India, Africa and plates in the Pacific Ocean basin by considering slab-pull, ridge-push and mantle drag/suction forces that naturally result from such top-down driven mantle flow. We compare the results with plate kinematic reconstructions and other geological observations.

  9. The Dynamics and Driving Force of Farmland Ecosystem Productivity

    ZHONG Liang-ping; SHAO Ming-an; LI Yu-shan


    Based on the experimental data of crop yield, soil water and fertility of a dryland farming ecosystem in northwest China, a systematic analysis is carried out to study the dynamics of dryland farming ecosystem productivity and its limiting factors. This paper also discusses which of the two limiting factors, i.e., soil water or fertility, is the primary factor and their dynamics. The result shows that fertility is the primary limiting factor when the productivity is rather low. As chemical fertilizer input increases and the productivity promotes, water gradually becomes the primary limiting factor. Chemical fertilizers and plastic film mulching are the two major driving forces that determine the crop productivity and its stability in these areas.

  10. Inflammaging: the driving force in osteoporosis?

    Lencel, P; Magne, D


    With advancing age, the balance between the amounts of old bone removed and new bone formed during the remodelling process becomes negative. In the past, it was commonly thought that skeletal involution was the result of age-related changes in other organs, and in particular from the decline in ovarian function in women at menopause. Nonetheless, with regard to emerging epidemiologic studies, the hypothesis suggesting that age-related changes such as inflammatory modifications importantly account for age-related bone loss is gaining increasing interest. Aging is indeed associated with immune dysfunction that coexists with a chronic subclinical inflammatory status. The latter is illustrated by a 2-4-fold increase in the levels C-reactive protein (CRP) or interleukin (IL)-6. This inflammatory status, which has been referred to by the neologism "inflammaging", is of sufficient magnitude to impact health and survival time, and correlates with age-related diseases such as atherosclerosis, insulin resistance and Alzheimer's disease. In this article, we first present the factors that condition inflammaging, and propose the hypothesis that inflammaging may be the driving force in age-related bone loss and may even be responsible for osteoporosis due to estrogen deficiency. Finally, we discuss the possibility that pro-inflammatory biomarkers may be used to provide clinical information for identifying patients at risk for osteoporosis, and the possibility that inflammatory cytokines may be targeted to improve bone formation in aged patients undergoing orthopaedic surgery.

  11. Inversion for the driving forces of plate tectonics

    Richardson, R. M.


    Inverse modeling techniques have been applied to the problem of determining the roles of various forces that may drive and resist plate tectonic motions. Separate linear inverse problems have been solved to find the best fitting pole of rotation for finite element grid point velocities and to find the best combination of force models to fit the observed relative plate velocities for the earth's twelve major plates using the generalized inverse operator. Variance-covariance data on plate motion have also been included. Results emphasize the relative importance of ridge push forces in the driving mechanism. Convergent margin forces are smaller by at least a factor of two, and perhaps by as much as a factor of twenty. Slab pull, apparently, is poorly transmitted to the surface plate as a driving force. Drag forces at the base of the plate are smaller than ridge push forces, although the sign of the force remains in question.

  12. Inversion for the driving forces of plate tectonics

    Richardson, R. M.


    Inverse modeling techniques have been applied to the problem of determining the roles of various forces that may drive and resist plate tectonic motions. Separate linear inverse problems have been solved to find the best fitting pole of rotation for finite element grid point velocities and to find the best combination of force models to fit the observed relative plate velocities for the earth's twelve major plates using the generalized inverse operator. Variance-covariance data on plate motion have also been included. Results emphasize the relative importance of ridge push forces in the driving mechanism. Convergent margin forces are smaller by at least a factor of two, and perhaps by as much as a factor of twenty. Slab pull, apparently, is poorly transmitted to the surface plate as a driving force. Drag forces at the base of the plate are smaller than ridge push forces, although the sign of the force remains in question.

  13. Rating forces grip and driving and accelerations of the car with drive different configuration

    Kowalski Mariusz


    Full Text Available The paper shows a typical drive systems used in today's vehicles, mainly cars. Approximated scheme of the formation of the driving force of the vehicle and the necessary mathematical relations for the calculation. For example, a typical passenger car BMW 320 was analyzed and calculations obtained a driving force, of adhesion and acceleration. The calculations were performed for the drive system, the classical (i.e. the rear axle of the vehicle for front-wheel drive and four-wheel drive (4×4. Virtually assumed that to the above mentioned vehicle it is possible buildings of each of said system. These are shown graphically in diagrams bearing a distribution of the forces acting on the substrate and the reactions - the data necessary for the calculations. The resulting calculation is graphically shown in the diagrams, in which is illustrated a change value of the resulting adhesive strength, and the acceleration depending on the drive type vehicle.

  14. OSHA Laboratory Standard: Driving Force for Laboratory Safety!

    Roy, Kenneth R.


    Discusses the Occupational Safety and Health Administration's (OSHA's) Laboratory Safety Standards as the major driving force in establishing and maintaining a safe working environment for teachers and students. (Author)

  15. Driving Force Filtering and Driving Mechanism Analysis of Urban Agricultural Development in Weifang County, China

    SUI Fei-fei


    Full Text Available As an agricultural nation, the agricultural landscape is the basic appearance and existence in China, but the common existence often be neglected and contempted. As a new type of design and ideology, the development of urban agricultural landscape will greatly affect the texture and structure of the urban space. According to the urban agricultural production data and the socio-economic data of Weifang County, a set of evaluation index system that could analyze quantitatively the driving force of urban agricultural production changes and the internal drive mechanism was built. The original driving force indicators of economy, society, resources and environment from the time-series were chosen, and then 15 driving forces from the original driving forces by correlation analysis and principal component analysis were selected. The degree of influence was analyzed and the driving forces model by means of partial least squares(PLS was built. The results demonstrated that the factors greatly influenced the increase of urban agricultural output value in Weifang County were per capita net income of rural residents, agricultural machinery total power, effective irrigation area, centralized treatment rate of urban sewage, with the driving exponents 0.2509, 0.1019, 0.1655, 0.1332, respectively. The negative influence factor was the use amount of agricultural plastic film and the driving exponent was-0.2146. The research provides a reference for the development of urban agriculture, as well as a reference for the related study.

  16. Shoulder muscle forces during driving: Sudden steering can load the rotator cuff beyond its repair limit.

    Pandis, Petros; Prinold, Joe A I; Bull, Anthony M J


    Driving is one of the most common everyday tasks and the rotator cuff muscles are the primary shoulder stabilisers. Muscle forces during driving are not currently known, yet knowledge of these would influence important clinical advice such as return to activities after surgery. The aim of this study is to quantify shoulder and rotator cuff muscle forces during driving in different postures. A musculoskeletal modelling approach is taken, using a modified driving simulator in combination with an upper limb musculoskeletal model (UK National Shoulder Model). Motion data and external force vectors were model inputs and upper limb muscle and joint forces were the outputs. Comparisons of the predicted glenohumeral joint forces were compared to in vivo literature values, with good agreement demonstrated (61 SD 8% body weight mean peak compared to 60 SD 1% body weight mean peak). High muscle activation was predicted in the rotator cuff muscles; particularly supraspinatus (mean 55% of the maximum and up to 164 SD 27 N). This level of loading is up to 72% of mean failure strength for supraspinatus repairs, and could therefore be dangerous for some cases. Statistically significant and large differences are shown to exist in the joint and muscle forces for different driving positions as well as steering with one or both hands (up to 46% body weight glenohumeral joint force). These conclusions should be a key consideration in rehabilitating the shoulder after surgery, preventing specific upper limb injuries and predicting return to driving recommendations. Copyright © 2015. Published by Elsevier Ltd.

  17. The Driving Forces of Subsidiary Absorptive Capacity

    Schleimer, Stephanie C.; Pedersen, Torben


    The study investigates how a multinational corporation (MNC) can promote the absorptive capacity of its subsidiaries. The focus is on what drives the MNC subsidiary's ability to absorb marketing strategies that are initiated by the MNC parent, as well as how the subsidiary enacts on this absorptive...... as a purposeful response to this dual embeddedness. An analysis of marketing strategy absorptions undertaken by 213 subsidiaries reveals that MNCs can assist their subsidiaries to compete in competitive and dynamic focal markets by forming specific organizational mechanisms that are conducive to the development...

  18. Contributions of Determining the Forces Distribution in the Harmonic Drive

    Sava Ianici


    Full Text Available The paper presents an original method for determining the forces distributions on the portant elements of the harmonic drives. This method is based on the thin wall shells theory anal on the rotating character of the distributed forces that work upon the flexible toothed wheel.

  19. Motive, desire, drive: the discourse of force

    Alan Blum


    Full Text Available A review of the original paper on motive by Blum and McHugh (1971 is used as an occasion to make transparent an approach to social theory as it has developed over the years in their work. This method, in treating motive as an illustration, engages it as an example of the status of the signifier as a symptom of interpretive conflict endemic to any situation of action, always inviting an analysis of the symbolic order and imaginative structure that sustains the distinction as a force in social life. In this paper, motive in particular is unpacked to show how it serves as an indication of fundamental ambiguity with respect to a problem-solving situation, revealing in this case constant perplexity in relation to the enigmatic character of what comes to view on any occasion and the recurrent contestation that is released.

  20. Ocean forcing drives glacier retreat sometimes

    Bassis, J. N.; Ultee, E.; Ma, Y.


    Observations show that marine-terminating glaciers respond to climate forcing nonlinearly, with periods of slow or negligible glacier advance punctuated by abrupt, rapid retreat. Once glacier retreat has initiated, glaciers can quickly stabilize with a new terminus position. Alternatively, retreat can be sustained for decades (or longer), as is the case for Columbia Glacier, Alaska where retreat initiated ~1984 and continues to this day. Surprisingly, patterns of glacier retreat show ambiguous or even contradictory correlations with atmospheric temperature and glacier surface mass balance. Despite these puzzles, observations increasingly show that intrusion of warm subsurface ocean water into fjords can lead to glacier erosion rates that can account for a substantial portion of the total mass lost from glaciers. Here we use a simplified flowline model to show that even relatively modest submarine melt rates (~100 m/a) near the terminus of grounded glaciers can trigger large increases in iceberg calving leading to rapid glacier retreat. However, the strength of the coupling between submarine melt and calving is a strong function of the geometry of the glacier (bed topography, ice thickness and glacier width). This can lead to irreversible retreat when the terminus is thick and grounded deeply beneath sea level or result in little change when the glacier is relatively thin, grounded in shallow water or pinned in a narrow fjord. Because of the strong dependence on glacier geometry, small perturbations in submarine melting can trigger glaciers in their most advanced—and geometrically precarious—state to undergo sudden retreat followed by much slower re-advance. Although many details remain speculative, our model hints that some glaciers are more sensitive than others to ocean forcing and that some of the nonlinearities of glacier response to climate change may be attributable to variations in difficult-to-detect subsurface water temperatures that need to be better

  1. Sequential reconstruction of driving-forces from nonlinear nonstationary dynamics

    Güntürkün, Ulaş


    This paper describes a functional analysis-based method for the estimation of driving-forces from nonlinear dynamic systems. The driving-forces account for the perturbation inputs induced by the external environment or the secular variations in the internal variables of the system. The proposed algorithm is applicable to the problems for which there is too little or no prior knowledge to build a rigorous mathematical model of the unknown dynamics. We derive the estimator conditioned on the differentiability of the unknown system’s mapping, and smoothness of the driving-force. The proposed algorithm is an adaptive sequential realization of the blind prediction error method, where the basic idea is to predict the observables, and retrieve the driving-force from the prediction error. Our realization of this idea is embodied by predicting the observables one-step into the future using a bank of echo state networks (ESN) in an online fashion, and then extracting the raw estimates from the prediction error and smoothing these estimates in two adaptive filtering stages. The adaptive nature of the algorithm enables to retrieve both slowly and rapidly varying driving-forces accurately, which are illustrated by simulations. Logistic and Moran-Ricker maps are studied in controlled experiments, exemplifying chaotic state and stochastic measurement models. The algorithm is also applied to the estimation of a driving-force from another nonlinear dynamic system that is stochastic in both state and measurement equations. The results are judged by the posterior Cramer-Rao lower bounds. The method is finally put into test on a real-world application; extracting sun’s magnetic flux from the sunspot time series.

  2. Measuring Industry Coagglomeration and Identifying the Driving Forces

    Howard, Emma; Newman, Carol; Tarp, Finn


    Understanding industry agglomeration and its driving forces is critical for the formulation of industrial policy in developing countries. Crucial to this process is the definition and measurement of agglomeration. We construct a new coagglomeration index based purely on the location of firms. We ...

  3. WP/084 Measuring Industry Agglomeration and Identifying the Driving Forces

    Howard, Emma; Tarp, Finn; Newman, Carol

    Understanding industry agglomeration and its driving forces is critical for the formulation of industrial policy in developing countries. Crucial to this process is the definition and measurement of agglomeration. We propose a new measure and examine what it reveals about the importance of transp...

  4. WP/084 Measuring Industry Agglomeration and Identifying the Driving Forces

    Howard, Emma; Tarp, Finn; Newman, Carol

    Understanding industry agglomeration and its driving forces is critical for the formulation of industrial policy in developing countries. Crucial to this process is the definition and measurement of agglomeration. We propose a new measure and examine what it reveals about the importance of transp......Understanding industry agglomeration and its driving forces is critical for the formulation of industrial policy in developing countries. Crucial to this process is the definition and measurement of agglomeration. We propose a new measure and examine what it reveals about the importance...... of transport costs, labour market pooling, and technology transfer for agglomeration processes. We contrast this analysis with insights from existing measures in the literature and find very different underlying stories at work. An exceptionally rich set of data from Vietnam makes us confident that our measure...

  5. Improved Generalized Force Model considering the Comfortable Driving Behavior

    De-Jie Xu


    Full Text Available This paper presents an improved generalized force model (IGFM that considers the driver’s comfortable driving behavior. Through theoretical analysis, we propose the calculation methods of comfortable driving distance and velocity. Then the stability condition of the model is obtained by the linear stability analysis. The problems of the unrealistic acceleration of the leading car existing in the previous models were solved. Furthermore, the simulation results show that IGFM can predict correct delay time of car motion and kinematic wave speed at jam density, and it can exactly describe the driver’s behavior under an urgent case, where no collision occurs. The dynamic properties of IGFM also indicate that stability has improved compared to the generalized force model.

  6. Impact assessment of land use planning driving forces on environment

    Chen, Longgao, E-mail: [Institute of Land Resources, Jiangsu Normal University (JSNU), Xuzhou 221116 (China); Yang, Xiaoyan [Institute of Land Resources, Jiangsu Normal University (JSNU), Xuzhou 221116 (China); School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116 (China); Chen, Longqian [School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116 (China); Li, Long [Department of Geography, Vrije Universiteit Brussel, Brussels 1050 (Belgium)


    Land use change may exert a negative impact on environmental quality. A state–impact–state (SIS) model describing a state transform under certain impacts has been integrated into land use planning (LUP) environmental impact assessment (LUPEA). This logical model is intuitive and easy to understand, but the exploration of impact is essential to establish the indicator system and to identify the scope of land use environmental impact when it is applied to a specific region. In this study, we investigated environmental driving forces from land use planning (LUPF), along with the conception, components, scope, and impact of LUPF. This method was illustrated by a case study in Zoucheng, China. Through the results, we concluded that (1) the LUPF on environment are impacts originated from the implementation of LUP on a regional environment, which are characterized by four aspects: magnitude, direction, action point, and its owner; (2) various scopes of LUPF on individual environmental elements based on different standards jointly define the final scope of LUPEA; (3) our case study in Zoucheng demonstrates the practicability of this proposed approach; (4) this method can be embedded into LUPEA with direction, magnitudes, and scopes of the LUPF on individual elements obtained, and the identified indicator system can be directly employed into LUPEA and (5) the assessment helps to identify key indicators and to set up a corresponding strategy to mitigate the negative impact of LUP on the environment, which are two important objectives of strategic environmental assessment (SEA) in LUP. - Highlights: • Environmental driving forces from land use planning (LUPF) are investigated and categorized. • Our method can obtains the direction, magnitudes and scopes of environmental driving forces. • The LUPEA scope is determined by the combination of various scopes of LUPF on individual elements. • LUPF assessment can be embedded into LUPEA. • The method can help to

  7. Solvent effects and driving forces in pillararene inclusion complexes.

    Schönbeck, Christian; Li, Hui; Han, Bao-Hang; Laursen, Bo W


    Pillararenes, a recently discovered class of aromatic macrocycles, form inclusion complexes with a large number of guest molecules, but not much is known about the driving forces of complexation, including the role of the solvent. We have measured the binding thermodynamics for a small number of model complexes in several solvents and used computational chemistry to rationalize the obtained results and identify the driving forces of complexation. Favorable electrostatic interactions between the host and guest are obtained when the charge distribution in the guest matches the negative electrostatic potential in the cavity of the pillararene. Polar guests, however, also interact strongly with polar solvents, thereby shifting the complexation equilibrium away from the complex. The shape of the solvent molecules is another important factor as some solvents are sterically hindered from entering the pillararene cavity. By changing solvent from acetonitrile to o-xylene the binding constant in one case increased more than 4 orders of magnitude. Even electrostatically similar solvents such as o-xylene and p-xylene have very different impacts on the binding constants due to their different abilities to fit into the cavity. The study illustrates the importance of taking into account the interactions between the solvent and the complexing species in the investigation and design of molecular host:guest systems.

  8. The driving forces of landscape change in Europe

    Plieninger, Tobias; Draux, Hélène; Fagerholm, Nora


    underrepresented landscapes; (b) clarifying the identification and role of actors in landscape change; (c) deploying more robust tools and methods to quantitatively assess the causalities of landscape change; (d) setting up long-term studies that go beyond mapping land-cover change only; (e) strengthening cross......Over the past decades, landscapes worldwide have experienced changes (e.g., urbanization, agricultural intensification, expansion of renewable energy uses) at magnitudes that put their sustainability at risk. The understanding of the drivers of these landscape changes remains challenging, partly...... because landscape research is spread across many domains and disciplines. We here provide a systematic synthesis of 144 studies that identify the proximate and underlying drivers of landscape change across Europe. First, we categorize how driving forces have been addressed and find that most studies...

  9. Multiple Forces Driving China's Economic Development: A New Analytic Framework

    Yahua Wang; Angang Hu


    Based on economic growth theory and the World Bank's analytical framework relating to the quality of growth, the present paper constructs a framework that encompasses physical, international, human, natural and knowledge capital to synthetically interpret economic development. After defining the five types of capital and total capital, we analyze the dynamic changes of these types of capital in China and in other countries. The results show that since China's reform and opening up, knowledge, international, human and physical capital have grown rapidly, with speeds of growth higher than that of economic growth. As the five types of capital have all increased at varying paces, the savings level of total capital in China has quadrupled in 25 years and overtook that of the USA in the 1990s. The changes in the five types of capital and total capital reveal that there are progressively multiple driving forces behind China's rapid economic development. Implications for China's long-term economic development are thereby raised.

  10. Models for Analyzing the Driving Force of Cultivated Land Supply Change

    LIU Yanfang; ZHANG Yuqian; XIAO Bin


    This paper focuses on a series of quantitative analysis models, such as grey relational analysis model, hierarchical cluster analysis model, principal component analysis model, linear regression model and elastic coefficient model. These models are used to analyze the comprehensive function and effect of driving forces systemically, including analysis on features, analysis for differentiating the primary and the secondary, analysis on comprehensive effects, analysis of elasticity, analysis of prediction. The primary and characteristic factors can be extracted by analysis of features and analysis for differentiating the primary and the secondary. Analysis on prediction and elasticity can predict the area of cultivated land in the future and find out which factors exert great influence on the cultivated land supply.

  11. Study on the Driving Forces of Rocky Desertification in Guizhou Province Based on Variation Coefficient Method


    [Objective] The aim was to study the driving forces of rocky desertification in Guizhou Province. [Method] Based on GIS and RS technology, the main driving forces of rocky desertification in Guizhou Province were analyzed by means of correlation analysis and variation coefficient method, and then the distribution of rocky desertification in Guizhou Province was assessed synthetically. [Result] The main driving forces of rocky desertification in Guizhou Province were vegetation cover, rainfall, peasant incom...

  12. Regional diversity of agricultural labor productivity and its driving force in east China

    Liu Ziqiang; Li Jing; Lu Qi


    China's eastern area is at middle and later stage of industrialization during which the relation between ur ban and rural areas,industry and agriculture appears maladjusted The main problems are shrinkage in agricultural somparative earning and lack of driving force of agricultural development.Based on calculating agricultural labor productivity in east China from 1996 to 2005,this paper analyzes contributing degree of motive forces of agriculture develop in ten provinces and cities of east China applying GCA (Grey correlative analysis).The results show that there is no absolute correspondence between the level of industrialization and agricultural labor productivity in Chi,na's cotstern area.There is no synchronous development between industry and agricultural labor productivity in some areas.Fertilizer and agricultural machinery input had high contributing degree for ten years; however,contributing degree in land and irrigation work input was low.Non-materialization inputs became the leading role in most provinc,es and cities' increase of agricultural labor productivity.Modern agricultural development need non-materializationinputs as primary motive.force,at the same time,direct material input and facility input as guaranteed function.Forsome reasons,agricultural development is characterized by "more direct material input,less facility input" in east China now.Optimal driving force model of future agricultural development in east China is that non-materializatior inputs are dominant that perfected facilitv input are guarantee,and that certain substance inputs are necessary.

  13. Electromagnet Tests on Primary Control Rod Drive Mechanism of a Prototype Gen-IV SFR

    Lee, Jaehan; Koo, Gyeonghoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The primary control system is used for power control, burn-up compensation and reactor shutdown in response to demands from the plant control or protection systems. This paper describes the lifting and holding force tests of the electromagnetic equipment of a primary control rod drive mechanism (CRDM). The supply currents above 1.5 A and 15A on coil are required for holding the CRA with a 1mm gap, and lifting the CRA with 10mm gap, respectively. The currents cover all the loads to be expected in driveline. The S10C carbon steel can be replaced with the SS410 stainless steel by increasing the supply current about 30%. The assist spring, pushing down the tension tube with a compressed force, plays an important role when the operation load is smaller than 20kgf. The spring force can cease a time delay on the free drop of the tension tube carrying a light driving mass because a residual electromagnetic force may exist for a while even though the supply power is cut off. The holding current can be reduced by closing the gap size of 1mm between inner core and armature.

  14. Effect of a powered drive on pushing and pulling forces when transporting bariatric hospital beds.

    Wiggermann, Neal


    Powered drives designed to assist with moving hospital beds are commercially available but no studies have evaluated whether they reduce the push and pull forces likely contributing to injury in caregivers. This study measured hand forces of 10 caregivers maneuvering a manual and powered bariatric bed through simulated hospital environments (hallway, elevator, and ramp). Peak push and pull forces exceeded previously established psychophysical limits for all activities with the manual bed. For the powered bed, peak forces were significantly (p forces between 38% (maneuvering into elevator) and 94% (descending ramp). Powered drive also reduced stopping distance by 55%. When maneuvering, the integral of hand force was 34% lower with powered drive, but average forces during straight-line pushing did not differ between beds. Powered drive may reduce the risk of injury or the number of caregivers needed for transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Cation charge dependence of the forces driving DNA assembly.

    DeRouchey, Jason; Parsegian, V Adrian; Rau, Donald C


    Understanding the strength and specificity of interactions among biologically important macromolecules that control cellular functions requires quantitative knowledge of intermolecular forces. Controlled DNA condensation and assembly are particularly critical for biology, with separate repulsive and attractive intermolecular forces determining the extent of DNA compaction. How these forces depend on the charge of the condensing ion has not been determined, but such knowledge is fundamental for understanding the basis of DNA-DNA interactions. Here, we measure DNA force-distance curves for a homologous set of arginine peptides. All forces are well fit as the sum of two exponentials with 2.4- and 4.8-Å decay lengths. The shorter-decay-length force is always repulsive, with an amplitude that varies slightly with length or charge. The longer-decay-length force varies strongly with cation charge, changing from repulsion with Arg¹ to attraction with Arg². Force curves for a series of homologous polyamines and the heterogeneous protein protamine are quite similar, demonstrating the universality of these forces for DNA assembly. Repulsive amplitudes of the shorter-decay-length force are species-dependent but nearly independent of charge within each species. A striking observation was that the attractive force amplitudes for all samples collapse to a single curve, varying linearly with the inverse of the cation charge.

  16. The driving forces of land change in the Northern Piedmont of the United States

    Auch, Roger F.; Napton, Darrell E.; Kambly, Steven; Moreland, Thomas R.; Sayler, Kristi L.


    Driving forces facilitate or inhibit land-use/land-cover change. Human driving forces include political, economic, cultural, and social attributes that often change across time and space. Remotely sensed imagery provides regional land-change data for the Northern Piedmont, an ecoregion of the United States that continued to urbanize after 1970 through conversion of agricultural and forest land covers to developed uses. Eight major driving forces facilitated most of the land conversion; other drivers inhibited or slowed change. A synergistic web of drivers may be more important in understanding land change than individual drivers by themselves.

  17. Three Dimensional Numerical Simulation for the Driving Force of Weld Solidification Cracking

    Zhibo DONG; Yanhong WEI; Renpei LIU; Zujue DONG


    The double ellipsoidal model of heat source is used to analyze the thermal distributions with a three dimensional finite element method (FEM). In the mechanical model, solidification effects are treated by a dynamic element rebirth scheme. The driving force is obtained in the cracking susceptible temperature range. Moreover, this paper presents the effect of solidification shrinkage, external restraint, weld start locations and material properties on the driving force. The comparison between the simulated driving force and the experimental measurements of the material resistance predicts the susceptibility of weld metal solidification cracking.

  18. Local vibrational coherences drive the primary photochemistry of vision

    Johnson, Philip J. M.; Halpin, Alexei; Morizumi, Takefumi; Prokhorenko, Valentyn I.; Ernst, Oliver P.; Miller, R. J. Dwayne


    The role of vibrational coherence—concerted vibrational motion on the excited-state potential energy surface—in the isomerization of retinal in the protein rhodopsin remains elusive, despite considerable experimental and theoretical efforts. We revisited this problem with resonant ultrafast heterodyne-detected transient-grating spectroscopy. The enhanced sensitivity that this technique provides allows us to probe directly the primary photochemical reaction of vision with sufficient temporal and spectral resolution to resolve all the relevant nuclear dynamics of the retinal chromophore during isomerization. We observed coherent photoproduct formation on a sub-50 fs timescale, and recovered a host of vibrational modes of the retinal chromophore that modulate the transient-grating signal during the isomerization reaction. Through Fourier filtering and subsequent time-domain analysis of the transient vibrational dynamics, the excited-state nuclear motions that drive the isomerization reaction were identified, and comprise stretching, torsional and out-of-plane wagging motions about the local C11=C12 isomerization coordinate.

  19. Driving forces of Indian summer monsoon on Milankovitch and sub-Milankovitch time scales: A review

    Naidu, P.D.

    and deep water circulation changes drive the variability of southwest (SW) monsoon in the Indian subcontinent. Different forcing factors act on different time scales. Arabian Sea sediments consist of distinct fauna that are endemic to areas of upwelling...

  20. Analysis of Korean Students' International Mobility by 2-D Model: Driving Force Factor and Directional Factor

    Park, Elisa L.


    The purpose of this study is to understand the dynamics of Korean students' international mobility to study abroad by using the 2-D Model. The first D, "the driving force factor," explains how and what components of the dissatisfaction with domestic higher education perceived by Korean students drives students' outward mobility to seek…

  1. Spatial and Temporal Dynamics in the Ionic Driving Force for GABAA Receptors

    R. Wright


    Full Text Available It is becoming increasingly apparent that the strength of GABAergic synaptic transmission is dynamic. One parameter that can establish differences in the actions of GABAergic synapses is the ionic driving force for the chloride-permeable GABAA receptor (GABAAR. Here we review some of the sophisticated ways in which this ionic driving force can vary within neuronal circuits. This driving force for GABAARs is subject to tight spatial control, with the distribution of Cl− transporter proteins and channels generating regional variation in the strength of GABAAR signalling across a single neuron. GABAAR dynamics can result from short-term changes in their driving force, which involve the temporary accumulation or depletion of intracellular Cl−. In addition, activity-dependent changes in the expression and function of Cl− regulating proteins can result in long-term shifts in the driving force for GABAARs. The multifaceted regulation of the ionic driving force for GABAARs has wide ranging implications for mature brain function, neural circuit development, and disease.

  2. How do cells produce and regulate the driving force in the process of migration?

    Zhong, Y.; Ji, B.


    Cell migration behaviors have been studied from various aspects and at different length scales (molecular, subcellular and cellular scales), however, the mechanisms of how cell produces and controls the driving force for its migration have not been fully understood. Here for the first time we draw a more unified picture of driving force production that integrates the mechanisms from molecular to subcellular and cellular levels to show how cell produces and regulates the driving force and thus control its motility. We suggest that although the external mechanical and chemical factors can influence cell migration, the cell is able to actively control and regulate its driving force for its motility through controlling the stability of cell adhesion via actively regulating its spreading shape. To demonstrate this picture of regulation of the driving force, a FEM-based simulation framework is developed by modeling the dynamics of adhesion at cell front, de-adhesion at cell rear, and forward motion of cell body under cell traction force for different cell shape. The migration of keratocyte and fibroblast cells is simulated for different matrix rigidity and rigidity gradient. We show that the cell migration speed biphasically depends on the matrix rigidity. The mechanism is that the variation of matrix rigidity tunes the balance of competition between stability of cell adhesion at cell front and instability of adhesion at cell rear, which consequently controls the driving force of cell migration. We further propose a parameter called motility factor for a quantitative description of impact of mechanical properties of matrix and cell shape on the driving force of cell migration.

  3. Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

    Miriam Jaafar


    Full Text Available We introduce drive-amplitude-modulation atomic force microscopy as a dynamic mode with outstanding performance in all environments from vacuum to liquids. As with frequency modulation, the new mode follows a feedback scheme with two nested loops: The first keeps the cantilever oscillation amplitude constant by regulating the driving force, and the second uses the driving force as the feedback variable for topography. Additionally, a phase-locked loop can be used as a parallel feedback allowing separation of the conservative and nonconservative interactions. We describe the basis of this mode and present some examples of its performance in three different environments. Drive-amplutide modulation is a very stable, intuitive and easy to use mode that is free of the feedback instability associated with the noncontact-to-contact transition that occurs in the frequency-modulation mode.

  4. Urbanization: Main Driving Force in Economic Development in Coming Years

    HuAn'gang; ZhaoBaohua; DavidKelly


    The past 25 years has seen an unprecedented exodus of rural immigrants flowing into cities or townships. Coastal China has become the main destination to take in the country's surplus farming labor forces in the rustic population; while the populous central or western provinces,

  5. Interaction forces drive the environmental transmission of pathogenic protozoa.

    Dumètre, Aurélien; Aubert, Dominique; Puech, Pierre-Henri; Hohweyer, Jeanne; Azas, Nadine; Villena, Isabelle


    The protozoan parasites Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii are pathogens that are resistant to a number of environmental factors and pose significant risks to public health worldwide. Their environmental transmission is closely governed by the physicochemical properties of their cysts (Giardia) and oocysts (Cryptosporidium and Toxoplasma), allowing their transport, retention, and survival for months in water, soil, vegetables, and mollusks, which are the main reservoirs for human infection. Importantly, the cyst/oocyst wall plays a key role in that regard by exhibiting a complex polymeric coverage that determines the charge and hydrophobic characteristics of parasites' surfaces. Interaction forces between parasites and other environmental particles may be, in a first approximation, evaluated following the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. However, due to the molecular topography and nano- to microstructure of the cyst/oocyst surface, non-DVLO hydrophobic forces together with additional steric attractive and/or repulsive forces may play a pivotal role in controlling the parasite behavior when the organism is subjected to various external conditions. Here, we review several parameters that enhance or hinder the adhesion of parasites to other particles and surfaces and address the role of fast-emerging techniques for mapping the cyst/oocyst surface, e.g., by measuring its topology and the generated interaction forces at the nano- to microscale. We discuss why characterizing these interactions could be a crucial step for managing the environmental matrices at risk of microbial pollution.

  6. The thermodynamic driving force for kinetics in general and enzyme kinetics in particular.

    Pekař, Miloslav


    The thermodynamic driving force of a reaction is usually taken as the chemical potential difference between products and reactants. The forward and backward reaction rates are then related to this force. This procedure is of very limited validity, as the resulting expression contains no kinetic factor and gives little information on reaction kinetics. The transformation of the reaction rate as a function of concentration (and temperature) into a function of chemical potential should be more properly performed, as illustrated by a simple example of an enzymatic reaction. The proper thermodynamic driving force is the difference between the exponentials of the totaled chemical potentials of reactants and products.

  7. Position and force control of a vehicle with two or more steerable drive wheels

    Reister, D.B.; Unseren, M.A.


    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  8. Position and force control of a vehicle with two or more steerable drive wheels

    Reister, D.B.; Unseren, M.A.


    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  9. Position and force control of a vehicle with two or more steerable drive wheels

    Reister, D.B.; Unseren, M.A.


    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.

  10. Experimental modeling of the effect of hurricane wind forces on driving behavior and vehicle performance.

    Rodriguez, Jose M; Codjoe, Julius; Osman, Osama; Ishak, Sherif; Wolshon, Brian


    While traffic planning is important for developing a hurricane evacuation plan, vehicle performance on the roads during extreme weather conditions is critical to the success of the planning process. This novel study investigates the effect of gusty hurricane wind forces on the driving behavior and vehicle performance. The study explores how the parameters of a driving simulator could be modified to reproduce wind loadings experienced by three vehicle types (passenger car, ambulance, and bus) during gusty hurricane winds, through manipulation of appropriate software. Thirty participants were then tested on the modified driving simulator under five wind conditions (ranging from normal to hurricane category 4). The driving performance measures used were heading error and lateral displacement. The results showed that higher wind forces resulted in more varied and greater heading error and lateral displacement. The ambulance had the greatest heading errors and lateral displacements, which were attributed to its large lateral surface area and light weight. Two mathematical models were developed to estimate the heading error and lateral displacements for each of the vehicle types for a given change in lateral wind force. Through a questionnaire, participants felt the different characteristics while driving each vehicle type. The findings of this study demonstrate the valuable use of a driving simulator to model the behavior of different vehicle types and to develop mathematical models to estimate and quantify driving behavior and vehicle performance under hurricane wind conditions.

  11. Tuning the driving force for exciton dissociation in single-walled carbon nanotube heterojunctions

    Ihly, Rachelle; Mistry, Kevin S.; Ferguson, Andrew J.; Clikeman, Tyler T.; Larson, Bryon W.; Reid, Obadiah; Boltalina, Olga V.; Strauss, Steven H.; Rumbles, Garry; Blackburn, Jeffrey L.


    Understanding the kinetics and energetics of interfacial electron transfer in molecular systems is crucial for the development of a broad array of technologies, including photovoltaics, solar fuel systems and energy storage. The Marcus formulation for electron transfer relates the thermodynamic driving force and reorganization energy for charge transfer between a given donor/acceptor pair to the kinetics and yield of electron transfer. Here we investigated the influence of the thermodynamic driving force for photoinduced electron transfer (PET) between single-walled carbon nanotubes (SWCNTs) and fullerene derivatives by employing time-resolved microwave conductivity as a sensitive probe of interfacial exciton dissociation. For the first time, we observed the Marcus inverted region (in which driving force exceeds reorganization energy) and quantified the reorganization energy for PET for a model SWCNT/acceptor system. The small reorganization energies (about 130 meV, most of which probably arises from the fullerene acceptors) are beneficial in minimizing energy loss in photoconversion schemes.

  12. Tuning the driving force for exciton dissociation in single-walled carbon nanotube heterojunctions

    Ihly, Rachelle; Mistry, Kevin S.; Ferguson, Andrew J.; Clikeman, Tyler T.; Larson, Bryon W.; Reid, Obadiah; Boltalina, Olga V.; Strauss, Steven H.; Rumbles, Garry; Blackburn, Jeffrey L.


    Understanding the kinetics and energetics of interfacial electron transfer in molecular systems is crucial for the development of a broad array of technologies, including photovoltaics, solar fuel systems and energy storage. The Marcus formulation for electron transfer relates the thermodynamic driving force and reorganization energy for charge transfer between a given donor/acceptor pair to the kinetics and yield of electron transfer. Here we investigated the influence of the thermodynamic driving force for photoinduced electron transfer (PET) between single-walled carbon nanotubes (SWCNTs) and fullerene derivatives by employing time-resolved microwave conductivity as a sensitive probe of interfacial exciton dissociation. For the first time, we observed the Marcus inverted region (in which driving force exceeds reorganization energy) and quantified the reorganization energy for PET for a model SWCNT/acceptor system. The small reorganization energies (about 130 meV, most of which probably arises from the fullerene acceptors) are beneficial in minimizing energy loss in photoconversion schemes.

  13. Impacts of Human Activity on Biodiversity——An Approach to Driving Force indicators

    RichardDawson; CaoZhiping


    The impact of human activity on biodiversity is very complicated, making it difficult to design practical indicators for assessment. Currently, state and response indicators are listed within Chapter 15 of Agenda 21, but no mention is made of driving force indicators and how they relate to biodiversity protection. This paper represents an effort to identify and then operationalize the idea of driving force indicators at national level. Five human induced factors affecting blodiversity were discussed: (a) habitat toss and fragmentation; (b) overexploitation of resources; (c) species introduction; (d) pollution; and (e) climate change. From these five factors, a subset was selected to serve as possible driving force indicators: (1) habitat loss, (2) the ratio of exotic species to indigenous ones, and (3) the change in pollution status. Although the three indicators are relatively simple, they cover the most important human impacts on biodiversity and offer the potential for further redefinition and ultimate use within the spirit of biodiversity protection.

  14. On Optimizing Steering Performance of Multi-axle Vehicle Based on Driving Force Control

    Wu Zhicheng


    Full Text Available The steering performance of multi-axle vehicle with independent driving system is affected by the distribution of the wheel driving force. A nonlinear vehicle dynamics model including magic formula tire model for describing 11 DoF four-axle vehicle with dual-front-axle-steering (DFAS system was presented. The influence of different driving force distribution scheme on the steering performance of the vehicle was analyzed. A control strategy for improving the steady response and transient response of the vehicle steering is proposed. The results show: For the steady response, setting different drive force for internal and external wheels according to the actual steering characteristics of the vehicle can effectively improve its steering characteristics; For the transient response, adopting the zero sideslip angle control strategy and using the PID control algorithm to control the driving force of the outside wheel of tear-two-axle, under angle step input, the vehicle sideslip angle can quickly stabilize to 0 and yaw rate also significantly decreases.

  15. CRISPR as a driving force: the Model T of biotechnology.

    Mariscal, Carlos; Petropanagos, Angel


    The CRISPR system for gene editing can break, repair, and replace targeted sections of DNA. Although CRISPR gene editing has important therapeutic potential, it raises several ethical concerns. Some bioethicists worry CRISPR is a prelude to a dystopian future, while others maintain it should not be feared because it is analogous to past biotechnologies. In the scientific literature, CRISPR is often discussed as a revolutionary technology. In this paper we unpack the framing of CRISPR as a revolutionary technology and contrast it with framing it as a value-threatening biotechnology or business-as-usual. By drawing on a comparison between CRISPR and the Ford Model T, we argue CRISPR is revolutionary as a product, process, and as a force for social change. This characterization of CRISPR offers important conceptual clarity to the existing debates surrounding CRISPR. In particular, conceptualizing CRISPR as a revolutionary technology structures regulatory goals with respect to this new technology. Revolutionary technologies have characteristic patterns of implementation, entrenchment, and social impact. As such, early identification of technologies as revolutionary may help construct more nuanced and effective ethical frameworks for public policy.




    Full Text Available The competitiveness of a nation is ensured by the profitable activity of firms. They strengthen their position in the domestic and international markets through global strategies whose purpose is to increase productivity and maintain it at a high level. For this, the company must take into account both the internal economic environment which ensures operating conditions and the external economic environment’s development. The five competitive forces determine the industry’s profitability because they configure firms’ selling prices, production costs and investments needed to be competitive in the field. The threat of new competitors limits the potential profit since they involve new production units and the opportunities for market expansion. Economic strength of the buyers and bidders attracts profits to them. Rivalry among existing competitors erodes profits by increasing costs of competition (like advertising, selling expenses or those required for research and development. The presence of substitutive goods or services limits competitors’ prices through buyers’ transfer phenomena limiting and eroding market share of industry / firm in the total production output.

  17. Preliminary Experimental Results for Indirect Vector-Control of Induction Motor Drives with Forced Dynamics

    Jan Vittek


    Full Text Available The contribution presents an extension of indirect vector control of electric drives employing induction motors to 'Forced Dynamic Control'. This method of control offers an accurate realisation of dynamic response profiles, which can be selected by the user. The developed system can be integrated into a drive with a shaft position encoder or a shaft sensoriess drive, in which only the stator currents are measured. The applied stator voltages are determined by a computed inverter switching algorithm. Simulation results and preliminary experimental results for indirect vector control of an idle running induction motor indicate good agreement with the theoretical predictions.

  18. Force control compensation method with variable load stiffness and damping of the hydraulic drive unit force control system

    Kong, Xiangdong; Ba, Kaixian; Yu, Bin; Cao, Yuan; Zhu, Qixin; Zhao, Hualong


    Each joint of hydraulic drive quadruped robot is driven by the hydraulic drive unit (HDU), and the contacting between the robot foot end and the ground is complex and variable, which increases the difficulty of force control inevitably. In the recent years, although many scholars researched some control methods such as disturbance rejection control, parameter self-adaptive control, impedance control and so on, to improve the force control performance of HDU, the robustness of the force control still needs improving. Therefore, how to simulate the complex and variable load characteristics of the environment structure and how to ensure HDU having excellent force control performance with the complex and variable load characteristics are key issues to be solved in this paper. The force control system mathematic model of HDU is established by the mechanism modeling method, and the theoretical models of a novel force control compensation method and a load characteristics simulation method under different environment structures are derived, considering the dynamic characteristics of the load stiffness and the load damping under different environment structures. Then, simulation effects of the variable load stiffness and load damping under the step and sinusoidal load force are analyzed experimentally on the HDU force control performance test platform, which provides the foundation for the force control compensation experiment research. In addition, the optimized PID control parameters are designed to make the HDU have better force control performance with suitable load stiffness and load damping, under which the force control compensation method is introduced, and the robustness of the force control system with several constant load characteristics and the variable load characteristics respectively are comparatively analyzed by experiment. The research results indicate that if the load characteristics are known, the force control compensation method presented in this

  19. Analysis of Urban Expansion and Driving Forces in Xuzhou City Based on Remote Sensing

    HU Zhao-ling; DU Pei-jun; GUO Da-zhi


    Based on satellite remote sensing TM/ETM+ images of Xuzhou city, land use forms of the city in 1987, 1994 and 2000 were extracted by using a neural network classification method. The expansion contribution rate and annual expansion intensity index of each administrative district have been calculated and the contribution rate matrices and spatial distribution maps of land use changes were obtained. Based on the above analysis, the characteristics of urban expansion from 1987 to 2000 have been explored. From 1987 to 1994, the expansion contribution rate of Quanshan district reached 46.80%, the highest in all administrative districts of Xuzhou city; Tongshan town was in a high-speed expansion period; both Quanshan and Yunlong districts were experiencing fast-speed expansion periods while the entire city was expanding at a medium-speed with an annual expansion intensity index of 0.98; the city spread eastwards and southwards. From 1994 to 2000, the expansion contribution rate of Quanshan district reached 43.67%, the highest in Xuzhou; the entire city was in a medium-speed expansion period with an annual expansion intensity index of 1.04; the city has rapidly been extended towards the southeast. According to the contribution rate matrices of land use changes, urban expansion mainly usurps cropland and woodland. A quantitative analysis found that population growth, industrialization and economic development are the primary driving forces behind urban expansion.

  20. Design and Synthesis of Distillation Systems using a Driving Force Based Approach

    Bek-Pedersen, Erik; Gani, Rafiqul


    A new integrated framework for synthesis, design and operation of distillation-based separation schemes is presented here. This framework is based on the driving force approach, which provides a measure of the differences in chemical/physical properties between two co-existing phases in a separat...

  1. Emission of greenhouse gases 1990-2010. Trends and driving forces



    Emissions of greenhouse gases in Norway from 1990-2010 - trends and driving forces, a report that presents emission trends in Norway with the analysis of the main drivers and trends, and a review and analysis of the effectiveness of implemented measures.(Author)

  2. Disruptive Innovations as a Driving Force for the Change of Wireless Telecommunication Infrastructures

    Kyoseva, Tsvetoslava; Poulkov, Vladimir; Mihaylov, Mihail Rumenov


    Innovations are the driving force for fundamental changes and development of future generation telecommunication networks. When considering innovations as drivers for the development of next generation telecommunication networks an important question is whether an innovative emerging technology...... would cause a disruption requiring fundamental change of the infrastructure or will it will only catalyze its evolution. This paper describes the major characteristics of disruptive innovations as a driving force for fundamental changes in existing telecommunications infrastructures. By analyzing...... the current trends in mobile communications, we reason that the emergence of new telecommunication architectures and infrastructures is inevitable. An important consideration in the analysis is the driving role of disruptive technologies for the future of telecommunications. Based on a model for evaluating...

  3. Quantum Statistics of a Forced Oscillator with a Time-Dependent Driving Force



    Quantum statistics of a forced harmonic oscillator acted upon by a time-dependent external force are derived using the Wilcox trick and the time-dependent inhomogeneous Bogoliubov transformation formalism.The internal energy,fluctuation of the particle-number average and entropy of this nonequilibrium system are presented explicitly.

  4. Traceable dynamic calibration of force transducers by primary means

    Vlajic, Nicholas; Chijioke, Ako


    We describe an apparatus for traceable, dynamic calibration of force transducers using harmonic excitation, and report calibration measurements of force transducers using this apparatus. In this system, the force applied to the transducer is produced by the acceleration of an attached mass, and is determined according to Newton’s second law, F  =  ma. The acceleration is measured by primary means, using laser interferometry. The capabilities of this system are demonstrated by performing dynamic calibrations of two shear-web-type force transducers up to a frequency of 2 kHz, with an expanded uncertainty below 1.2%. We give an account of all significant sources of uncertainty, including a detailed consideration of the effects of dynamic tilting (rocking), which is a leading source of uncertainty in such harmonic force calibration systems.

  5. Design considerations of electromagnetic force in a direct drive permanent magnet brushless motor

    Chen, H. S.; Tsai, M. C.


    In this paper, a numerical study of electromagnetic force associated with the width of stator teeth, width of rotor back iron, and slot opening for a ten-pole nine-slot direct drive permanent magnet brushless motor is presented. The study calculates the amplitude of the electromagnetic force on the rotating rotor by using the finite-element method. The results show that the amplitude of electromagnetic force, which may cause the noise and vibration of motors, changes with the variation of these above mentioned three factors. The relationship between the considerations of output torque and the minimization of noise and vibration is also established in this paper.

  6. Current Reversal Due to Coupling Between Asymmetrical Driving Force and Ratchet Potential


    Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potential are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal. The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.

  7. Driving-forces model on individual behavior in scenarios considering moving threat agents

    Li, Shuying; Zhuang, Jun; Shen, Shifei; Wang, Jia


    The individual behavior model is a contributory factor to improve the accuracy of agent-based simulation in different scenarios. However, few studies have considered moving threat agents, which often occur in terrorist attacks caused by attackers with close-range weapons (e.g., sword, stick). At the same time, many existing behavior models lack validation from cases or experiments. This paper builds a new individual behavior model based on seven behavioral hypotheses. The driving-forces model is an extension of the classical social force model considering scenarios including moving threat agents. An experiment was conducted to validate the key components of the model. Then the model is compared with an advanced Elliptical Specification II social force model, by calculating the fitting errors between the simulated and experimental trajectories, and being applied to simulate a specific circumstance. Our results show that the driving-forces model reduced the fitting error by an average of 33.9% and the standard deviation by an average of 44.5%, which indicates the accuracy and stability of the model in the studied situation. The new driving-forces model could be used to simulate individual behavior when analyzing the risk of specific scenarios using agent-based simulation methods, such as risk analysis of close-range terrorist attacks in public places.

  8. Social visual contact, a primary "drive" for social animals?

    Perret, Audrey; Henry, Laurence; Coulon, Marion; Caudal, Jean-Pierre; Richard, Jean-Pierre; Cousillas, Hugo; Hausberger, Martine; George, Isabelle


    Social animals are always searching for conspecifics, thereby expressing a genuine "social need". This need is illustrated by the fact that social isolation can induce isolation syndromes that can be attenuated by devices such as mirrors. Social contacts appear to be so vital for social animals that they may be ready to work to obtain social stimulations. We used operant conditioning to investigate the possibility to use visual contact (through pictures of conspecifics) as a primary reinforcer. Isolated European starlings (Sturnus vulgaris) were offered the choice of seeing either social images (i.e. pictures of conspecifics) or non-social images (i.e. pictures of landscapes or pictures of monkeys) by triggering sensors. In contrast with most studies, our subjects were presented still pictures of conspecifics and not videos. Moreover, these pictures were used as primary reinforcers and thus were not paired with food. Our data show that starlings were ready to work and to use the apparatus (i.e. sensors) to see pictures in the absence of any other reward. Moreover, they actively and significantly preferred pictures of conspecifics to pictures of inanimate objects (landscapes) or of heterospecifics (monkeys). This suggests that 2D pictures with a social overtone can be used as primary reinforcers for isolated social birds.

  9. A Study of the Effect of the Fringe Fields on the Electrostatic Force in Vertical Comb Drives

    Else Gallagher


    Full Text Available The equation that describes the relationship between the applied voltage and the resulting electrostatic force within comb drives is often used to assist in choosing the dimensions for their design. This paper re-examines how some of these dimensions—particularly the cross-sectional dimensions of the comb teeth—affect this relationship in vertical comb drives. The electrostatic forces in several vertical comb drives fabricated for this study were measured and compared to predictions made with four different mathematical models in order to explore the amount of complexity required within a model to accurately predict the electrostatic forces in the comb drives.

  10. Position Control of Linear Synchronous Motor Drives with Exploitation of Forced Dynamics Control Principles

    Jan Vittek


    Full Text Available Closed-loop position control of mechanisms directly driven by linear synchronous motors with permanent magnets is presented. The control strategy is based on forced dynamic control, which is a form of feedback linearisation, yielding a non-liner multivariable control law to obtain a prescribed linear speed dynamics together with the vector control condition of mutal orthogonality between the stator current and magnetic flux vectors (assuming perfect estimates of the plant parameters. Outer position control loop is closed via simple feedback with proportional gain. Simulations of the design control sysstem, including the drive with power electronic switching, predict the intended drive performance.

  11. Analyzing the Long Term Cohesive Effect of Sector Specific Driving Forces.

    Berman, Yonatan; Ben-Jacob, Eshel; Zhang, Xin; Shapira, Yoash


    Financial markets are partially composed of sectors dominated by external driving forces, such as commodity prices, infrastructure and other indices. We characterize the statistical properties of such sectors and present a novel model for the coupling of the stock prices and their dominating driving forces, inspired by mean reverting stochastic processes. Using the model we were able to explain the market sectors' long term behavior and estimate the coupling strength between stocks in financial markets and the sector specific driving forces. Notably, the analysis was successfully applied to the shipping market, in which the Baltic dry index (BDI), an assessment of the price of transporting the major raw materials by sea, influences the shipping financial market. We also present the analysis of other sectors-the gold mining market and the food production market, for which the model was also successfully applied. The model can serve as a general tool for characterizing the coupling between external forces and affected financial variables and therefore for estimating the risk in sectors and their vulnerability to external stress.

  12. Analyzing the Long Term Cohesive Effect of Sector Specific Driving Forces.

    Yonatan Berman

    Full Text Available Financial markets are partially composed of sectors dominated by external driving forces, such as commodity prices, infrastructure and other indices. We characterize the statistical properties of such sectors and present a novel model for the coupling of the stock prices and their dominating driving forces, inspired by mean reverting stochastic processes. Using the model we were able to explain the market sectors' long term behavior and estimate the coupling strength between stocks in financial markets and the sector specific driving forces. Notably, the analysis was successfully applied to the shipping market, in which the Baltic dry index (BDI, an assessment of the price of transporting the major raw materials by sea, influences the shipping financial market. We also present the analysis of other sectors-the gold mining market and the food production market, for which the model was also successfully applied. The model can serve as a general tool for characterizing the coupling between external forces and affected financial variables and therefore for estimating the risk in sectors and their vulnerability to external stress.

  13. Theoretical critical value curve and driving force formation of ecological migration in the arid land

    ZHU Zi'an; ZHANG Xiaolei


    The features of the fragile eco-environment of the arid land decide that its capacity of disturbance-resistance is lower. The natural desert oases in the arid land are in mosaic patches distributed in a wide Gobi desert. The population distribution is greatly dependent on water resources. The population is characterized with dispersed distribution, simple production and living style, and poverty and remoteness. The reason why the ecological migrations are carried out lies in the ecological problems. "Ecological degradation" is the main driving force of the ecological migration. Then, the strength of the driving force depends on the degree of ecological degradation. Hence, whether to carry out ecological migration depends on the extent of ecological degradation.Theoretically, the critical value curve for calculating ecological migration in the arid land is put forward through comprehensive research of relative problems of ecology, economics etc., combined with the ecological migration experience in the arid land, and based on the features of the arid environment. In this article, with this curve, the theoretical research and some practice of the ecological migration have been done from the perspective of natural behavior and governmental behavior of the driving force formation of ecological migration. It analyses the active driving force (factors) and negative forces (factors), and points out the timing and steps of implementing the ecological migration in the arid land. The theoretical curve embodies certain originality and applicability,which provides a quantitative method for evaluating 196the degree of ecological degradation and the theoretical base for implementing ecological migration projects.

  14. Impaired driving performance associated with effect of time duration in patients with primary insomnia.

    Perrier, Joy; Bertran, Françoise; Marie, Sullivan; Couque, Colette; Bulla, Jan; Denise, Pierre; Bocca, Marie-Laure


    To evaluate driving performance and psychomotor vigilance in patients with primary insomnia. After 1 night of polysomnography, participants performed a 1-h simulated monotonous driving task and a psychomotor vigilance task (PVT). Self-ratings of sleepiness, mood, and driving performance were completed. This study was conducted at the CHU of Caen Sleep Unit and the University of Caen. Twenty-one primary insomnia patients and 16 good sleepers. Not applicable. Results revealed a larger standard deviation of lateral position (P = 0.023) and more lane crossings (P = 0.03) in insomnia patients than in good sleepers. Analyses of effect of time on task performance showed that the impairment in patients occurred after 20 min of driving, which was not the case for good sleepers. No difference between groups was found for the PVT, neither for the mean reaction time (RT) (P = 0.43) nor the number of lapses (P = 0.21) and the mean slowest 10% 1/RT (P = 0.81). Patients rated their sleepiness level higher (P = 0.06) and their alertness level lower (P = 0.007) than did good sleepers (P = 0.007). The self-evaluation of the driving performance was not different between groups (P = 0.15). These findings revealed that primary insomnia is associated with a performance decrement during a simulated monotonous driving task. We also showed that patients are able to drive safely only for a short time. It appears advisable for clinicians to warn patients about their impaired driving performance that could lead to an increased risk of driving accidents. © 2014 Associated Professional Sleep Societies, LLC.

  15. Dynamic tensile forces drive collective cell migration through three-dimensional extracellular matrices

    Gjorevski, Nikolce; S. Piotrowski, Alexandra; Varner, Victor D.; Nelson, Celeste M.


    Collective cell migration drives tissue remodeling during development, wound repair, and metastatic invasion. The physical mechanisms by which cells move cohesively through dense three-dimensional (3D) extracellular matrix (ECM) remain incompletely understood. Here, we show directly that migration of multicellular cohorts through collagenous matrices occurs via a dynamic pulling mechanism, the nature of which had only been inferred previously in 3D. Tensile forces increase at the invasive front of cohorts, serving a physical, propelling role as well as a regulatory one by conditioning the cells and matrix for further extension. These forces elicit mechanosensitive signaling within the leading edge and align the ECM, creating microtracks conducive to further migration. Moreover, cell movements are highly correlated and in phase with ECM deformations. Migrating cohorts use spatially localized, long-range forces and consequent matrix alignment to navigate through the ECM. These results suggest biophysical forces are critical for 3D collective migration. PMID:26165921

  16. Environmental technology: legislation as a driving force for development; Miljoeteknologi: lovverket som drivkraft for utviklingen



    Technology development providing a reduced pressure on the environment is necessary for a sustainable development. In order to promote such a development in technology, it is important to know which driving forces and barriers influence these processes. Factors contributing to the development of seven technologies are studied, and in general these regulations have played a bigger role for the development than 'pure market forces'. For many participants it is important to be one step ahead of the regulations, i.e. expected regulations are equally important as factual ones in driving the technology development. Simultaneously it is important that the authorities cooperate with the business when introducing new regulations. This will increase acceptance for the regulations and facilitate the necessary adjustments. The most important barrier in the development and use of the technologies studied is probably the lack of demand.


    LI Fang; HE Yan-fen; LIU Zhi-ming; ZHANG Bai


    By establishing the interpreting elements, and applying supervised classification, the sandy desertification was interpreted and the desertified land areas of the counties in the western Jilin Province in 1986 and in 2000 were obtained. Taking Tongyu and Qian'an as examples, the natural driving forces and man-made driving forces were analyzed. The paper comes the conclusions that the material sources and the warming and dry climate are the internal causes of potential land desertification; the irrational human activities, such as destroying forest and reclaiming the grassland, are the external causes of potential land desertification; while more rational human activities, such as planting trees and restoring grassland can reverse the land desertification. Furthermore, the countermeasures and suggestions for the development of agriculture and animal husbandry in the western Jilin Province are put forward.

  18. Application of Laser Ranging and VLBI Data to a Study of Plate Tectonic Driving Forces

    Solomon, S. C.


    The conditions under which changes in plate driving or resistive forces associated with plate boundary earthquakes are measurable with laser ranging or very long base interferometry were investigated. Aspects of plate forces that can be characterized by such measurements were identified. Analytic solutions for two dimensional stress diffusion in a viscoelastic plate following earthquake faulting on a finite fault, finite element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting, and quantitative constraints from modeling of global intraplate stress on the magnitude of deviatoric stress in the lithosphere are among the topics discussed.

  19. Finite Element Analysis of the Vertical Levitation Force in an Electrostatic MEMS Comb Drive Actuator

    Wooldridge, J.; Blackburn, J.; Muniz-Piniella, A.; Stewart, M.; Shean, T. A. V.; Weaver, P. M.; Cain, M. G.


    A vertical levitation electrostatic comb drive actuator was manufactured for the purpose of measuring piezoelectric coefficients in small-scale materials and devices. Previous modelling work on comb drive levitation has focussed on control of the levitation in standard poly-silicon devices in order to minimize effects on lateral modes of operation required for the accelerometer and gyroscope applications. The actuator developed in this study was manufactured using a 20 μm electroplated Ni process with a 25 μm trench created beneath the released structure through chemical wet etching. A finite element analysis using ZINC was used to model electrostatic potential around a cross section of one static and one movable electrode, from which the net levitation force per unit electrode was calculated. The model was first verified using the electrode geometry from previously studied systems, and then used to study the variation of force as a function of decreasing substrate-electrode distance. With the top electrode surfaces collinear the calculated force density is 0.00651 epsilon0V2Mμm-1, equivalent to a total force for the device of 36.4 μN at an applied voltage of VM=100 V, just 16% larger than the observed value. The measured increase in force with distance was smaller than predicted with the FEA, due to the geometry of the device in which the electrodes at the anchored ends of the supporting spring structure displace by a smaller amount than those at the centre.

  20. Electronic structure and driving forces in {beta}-cyclodextrin: Diclofenac inclusion complexes

    Bogdan, Diana [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania); Morari, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath street 71-103, 400293 Cluj-Napoca (Romania)]. E-mail:


    We investigate the geometry and electronic structure for complexes of {beta}-cyclodextrin with diclofenac using DFT calculations. The effect of solvent is explicitly taken into account. This investigation allows us to draw meaningful conclusions upon the stability of the complex and the nature of the driving forces leading to the complexation process. In particular we emphasize the role of the water, by pointing out the changes in the solvent's electronic structure for different docking geometries.

  1. Understanding Driving Forces and Implications Associated with the Land Use and Land Cover Changes in Portugal

    Bruno M. Meneses


    Full Text Available Understanding the processes of land use and land cover changes (LUCC and the associated driving forces is important for achieving sustainable development. This paper presents the LUCC in Portugal at the regional level (NUTS II from 1995 to 2010 and discusses the main driving forces and implications associated with these LUCC. The main objectives of this work are: (a to quantify the land use and land cover (LUC types (level I of LUC cartography by NUT II in Portugal for the years 1995, 2007 and 2010; (b to assess the spatio-temporal LUCC; and (c to identify and discuss the main driving forces of LUCC and corresponding implications based on correlations and Principal Components Analysis. The results revealed large regional and temporal LUCC and further highlighted the different and sometimes opposite time trends between neighboring regions. By associating driving forces to LUCC, different influences at the regional level were observed, namely LUCC into agriculture land derived from the construction of dams (Alentejo region, or the conversion of coniferous forest into eucalypt forest (Centre region associated with increased gross value added (GVA and employment in industry and forestry. Temporal differentiation was also observed, particularly in the settlements that expanded between 1995 and 2007 due to the construction of large infrastructures (e.g., highways, industrial complexes, or buildings, which is reflected on employment in industry and construction and respective GVA. However, certain LUCC have implications, particularly in energy consumption, for which different behavior between regions can be highlighted in this analysis, but also on land-use sustainability.

  2. Alien plant invasions in South Africa: driving forces and the human dimension

    Le Maitre, David C


    Full Text Available secondary driving forces ? Human population growth and migration Population increases lead to greater demands for food and materials. These demands are met by increasing productivity throughfertilization,adoptionofnewspecies,andbyincreasing the area under... production.1,35,37,48 Where demands cannot be met, people tend to migrate, taking propagules of their custom- ary food and medicinal plant species with them31,49 and inadver- tently carrying invasive species. ? Expanding network of international trade...

  3. Spatiotemporal Modeling of Urban Growth Predictions Based on Driving Force Factors in Five Saudi Arabian Cities

    Abdullah F. Alqurashi


    Full Text Available This paper investigates the effect of four driving forces, including elevation, slope, distance to drainage and distance to major roads, on urban expansion in five Saudi Arabian cities: Riyadh, Jeddah, Makkah, Al-Taif and Eastern Area. The prediction of urban probabilities in the selected cities based on the four driving forces is generated using a logistic regression model for two time periods of urban change in 1985 and 2014. The validation of the model was tested using two approaches. The first approach was a quantitative analysis by using the Relative Operating Characteristic (ROC method. The second approach was a qualitative analysis in which the probable urban growth maps based on urban changes in 1985 is used to test the performance of the model to predict the probable urban growth after 2014 by comparing the probable maps of 1985 and the actual urban growth of 2014. The results indicate that the prediction model of 2014 provides a reliable and consistent prediction based on the performance of 1985. The analysis of driving forces shows variable effects over time. Variables such as elevation, slope and road distance had significant effects on the selected cities. However, distance to major roads was the factor with the most impact to determine the urban form in all five cites in both 1985 and 2014.

  4. Spatiotemporal Variation of Driving Forces for Settlement Expansion in Different Types of Counties

    Guanglong Dong


    Full Text Available Understanding the process of settlement expansion and the spatiotemporal variation of driving forces is the foundation of rational and specific planning for sustainable development. However, little attention has been paid to the spatiotemporal differences of driving forces among different counties, especially when they are representatives of different development types. This study used Guanyun, Kunshan and Changshu as case studies, and binary logistic regression was employed. The results showed that the expansion rates of Kunshan and Changshu were 5.55 and 3.93 times higher than that of Guanyun. The combinations and relative importance of drivers varied with counties and periods. The change in the number of driving forces can be divided into three stages: increasing stage, decreasing stage, and stable stage. In the relatively developed counties, Kunshan and Changshu, the importance of population is decreased, while it remain an important factor in the less developed county, Guanyun. In addition, the effect of GDP stays the same in Kunshan while it becomes the most important factor in Changshu. The distance to the main road and the distance to town are increasingly important in Kunshan and Guanyun, and distance to town has been the only common factor in the last period, indicating the discrepancy is increased. The relative importance of distance to a lake in Kunshan and Changshu increased, reflecting the role of increasing tourism in accelerating settlement expansion.

  5. Analysis of two phase mass transfer kinetics by logarithmic driving force based on chemical thermodynamics

    Nabeshima, Masahiro (Sumitomo Metal Mining Co. Ltd., Tokai, Ibaraki (Japan). Tokai Research Center)


    Interphase transfer kinetics of neodymium and nitric acid was studied using a single drop column with recycling organic phase via an external mixing vessel in H[sub 2]O-HNO[sub 3]/NaNO[sub 3]-Nd(NO[sub 3])[sub 3]-tri-n-butylphosphate system. Experimental data have been analyzed by two new concepts for driving forces for transport: synthesized linear and logarithmic forms. The former is defined as geometrical-mean driving force, and the latter is the logarithm of the product of reciprocals of concentration ratios x/x[sup e] and y/y[sup e] against equilibrium states in each phase, i.e. ln[l brace]x[sup e][center dot]y([sup e])/(x[center dot]y)[r brace]. By applying thermodynamic logarithmic form of driving force along reaction coordinate, the net transfer fluxes of neodymium and nitric acid have been represented by chemical affinity under high ionic strengths over a wide range of solvent loading as flux=flux deg[sub f](1-exp(-A/RT)). (author).

  6. Force rebalance control for a MEMS gyroscope using ascending frequency drive and generalized PI control

    He Chun-Hua


    Full Text Available This paper has proposed a novel force rebalance control method for a MEMS gyroscope using ascending frequency drive and generalized PI control. Theoretical analyses of ascending frequency drive and force rebalance control methods are illustrated in detail. Experimental results demonstrate that the electrical anti-resonant peaks are located at the frequency responses in the RFD system, which seriously deteriorates the original response characteristics. However, they are eliminated in the AFD system, and the electrical coupling signal is also suppressed. Besides, as for the force rebalance control system, the phase margins approximate to 60deg, gain margins are larger than 13dB, and sensitivity margins are smaller than 3.2dB, which validates the control system is stable and robust. The bandwidth of the force rebalance control system is measured to be about 103.2Hz, which accords with the simulation result. The bias instability and angle random walk are evaluated to be 1.65deg/h and 0.06deg/√h, respectively, which achieves the tactical level.

  7. Mechanisms driving variability in the ocean forcing of Pine Island Glacier

    Webber, Benjamin G. M.; Heywood, Karen J.; Stevens, David P.; Dutrieux, Pierre; Abrahamsen, E. Povl; Jenkins, Adrian; Jacobs, Stanley S.; Ha, Ho Kyung; Lee, Sang Hoon; Kim, Tae Wan


    Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG and nearby glaciers. However, the variability of the ocean forcing of PIG has been poorly constrained due to a lack of multi-year observations. Here we show, using a unique record close to the Pine Island Ice Shelf (PIIS), that there is considerable oceanic variability at seasonal and interannual timescales, including a pronounced cold period from October 2011 to May 2013. This variability can be largely explained by two processes: cumulative ocean surface heat fluxes and sea ice formation close to PIIS; and interannual reversals in ocean currents and associated heat transport within Pine Island Bay, driven by a combination of local and remote forcing. Local atmospheric forcing therefore plays an important role in driving oceanic variability close to PIIS.

  8. Conceptual Design on Primary Control Rod Drive Mechanism of a Prototype Gen-IV SFR

    Lee, Jae Han; Koo, Gyeong Hoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    This paper describes the key concept of the drive mechanism, and suggests a required motor power and reducer gears to meet the functional design requirements, and a seismic response analysis of CRDM housing is performed to check its structural integrity. An AC servo motor is selected as a CRA driving power because it uses permanent magnets and is brushless type while DC motor needs a brush and a coil rotates. The control shim motor size is constrained by a housing diameter of 250mm. The driving system has several design requirements. To calculate the motor power, the drive shaft torque is needed. One part of the drive shaft has a lead screw, driving by a ball-nut. The ball screw driver torque (Tr) is calculated by some equations as follow; A servo motor with a nominal power of 100W, a nominal torque of 0.32 N-m (max. 0.48N-m) is selected considering a safety margin. Its diameter is about 50mm. The fast drive-in motor needs a strong power to insert enforcedly the stuck CRA into core within a required time. The motor sizes are calculated by the same procedure. The diameters are in the range of 80mm to 110mm by the insertion time (10 ∼ 24 seconds). The prototype Gen-IV SFR (sodium-cooled Fast Reactor) is of 150MWe capacity. The reactor has six primary control rod assemblies(CRAs). The primary control rod is used for power control, burn-up compensation and reactor shutdown in response to demands from the plant control or protection systems. The control rod drive mechanism (CRDM) consists of the drive motor assembly, the driveline, and its housing. The driveline consists of three concentric members of a drive shaft, a tension tube, and a position indicator rod, and it connects the drive motor assembly to the CRA. Main issue is that these many driving parts shall be enclosed within a limited housing diameter because the available pitch of CRDMs is limited by 300mm.

  9. Nature of the coupling between neural drive and force-generating capacity in the human quadriceps muscle.

    Hug, François; Goupille, Clément; Baum, Daniel; Raiteri, Brent J; Hodges, Paul W; Tucker, Kylie


    The force produced by a muscle depends on both the neural drive it receives and several biomechanical factors. When multiple muscles act on a single joint, the nature of the relationship between the neural drive and force-generating capacity of the synergistic muscles is largely unknown. This study aimed to determine the relationship between the ratio of neural drive and the ratio of muscle force-generating capacity between two synergist muscles (vastus lateralis (VL) and vastus medialis (VM)) in humans. Twenty-one participants performed isometric knee extensions at 20 and 50% of maximal voluntary contractions (MVC). Myoelectric activity (surface electromyography (EMG)) provided an index of neural drive. Physiological cross-sectional area (PCSA) was estimated from measurements of muscle volume (magnetic resonance imaging) and muscle fascicle length (three-dimensional ultrasound imaging) to represent the muscles' force-generating capacities. Neither PCSA nor neural drive was balanced between VL and VM. There was a large (r = 0.68) and moderate (r = 0.43) correlation between the ratio of VL/VM EMG amplitude and the ratio of VL/VM PCSA at 20 and 50% of MVC, respectively. This study provides evidence that neural drive is biased by muscle force-generating capacity, the greater the force-generating capacity of VL compared with VM, the stronger bias of drive to the VL.

  10. Land use change and its driving forces in alluvial-plain oasis

    Xiao, Luxiang; Zhang, Zengxiang; Chen, Xi; Luo, Geping; Wen, Qingke


    Land use change and its driving factors are hot topics of global change research, and also important topics of sustainable development. This paper selected a small area in alluvial plain oasis in Xinjiang Autonomous region of China as the study area. Using Landsat TM data of 1987, 1998 and 2004, the dynamic process of the spatial-temporal characteristics of land use changes were analyzed to improve understanding and to find the driving forces of land use changes so that sustainable land utilization could be practiced. During the 17 years salt-alkali tolerant cropland, cereal cropland, vegetable-fruit land, and shrubbery, had decreased remarkably by 78.59%, 85.95%, 92.13%, 68.43%, respectively. Cotton-liquorice land, grape-hop land, planted forest, residential area in town, residential area in village, and saline-alkaline field had increased dramatically. The increased percentage received the value of 2432.11%, 10103.18%, 889.91%, 222.45%, 96.00%, 44.18%, respectively. By the logistic regression, the main driving factors were derived for each land use type. The advance of technology (fertilizer input, irrigation quota, and animal labor et al.) and market (unit are yield net) were the main driving factors. Policy, in a higher level, influenced the land use dynamics for all the land use changes.

  11. Molecular simulations of primary alkanolamines using an extendable force field.

    Simond, Mickaël R; Ballerat-Busserolles, Karine; Coxam, Jean-Yves; Pádua, Agílio A H


    A classical force field is proposed for the molecular simulation of primary alkanolamines containing a NH(2)-C-C-OH backbone. A method is devised to take into account the polar (H-bonding) environment of the alkanolamines by calculating electrostatic charges in the presence of explicit solvent molecules. The force field does not use a universal set of charges, but is rather constructed by following a general method for obtaining specific charges for the different alkanolamines. The model is parameterized on the two simplest primary alkanolamines and then validated by calculating thermodynamic properties of five other molecules. Experimental liquid densities and enthalpies of vaporization are also reported in order to complete existing literature data. The predicted ability of the force field is evaluated by comparing the simulation results with experimental densities and enthalpies of vaporization. Densities are predicted with an uncertainty of 1.5 % and enthalpies of vaporization with an uncertainty of 1 kJ mol(-1). A decomposition of the interaction energy into electrostatic and repulsive-dispersive interactions and an analysis of hydrogen-bond statistics lead to a complex picture. Some terms of these interactions are related to the molecular structure in a clear way, others are not. The results provide insights into the structure-property relations that contribute to a better description of the thermodynamic properties of alkanolamines.

  12. Associated decrements in rate of force development and neural drive after maximal eccentric exercise.

    Farup, J; Rahbek, S K; Bjerre, J; de Paoli, F; Vissing, K


    The present study investigated the changes in contractile rate of force development (RFD) and the neural drive following a single bout of eccentric exercise. Twenty-four subjects performed 15 × 10 maximal isokinetic eccentric knee extensor contractions. Prior to and at 24, 48, 72, 96, and 168 h during post-exercise recovery, isometric RFD (30, 50 100, and 200 ms), normalized RFD [1/6,1/2, and 2/3 of maximal voluntary contraction (MVC)] and rate of electromyography rise (RER; 30, 50, and 75 ms) were measured. RFD decreased by 28-42% peaking at 48 h (P eccentric exercise. This association suggests that exercise-induced decrements in RFD can, in part, be explained decrements in neural drive. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Driving Forces and Development Strategies of China’s Agro-tourism

    Ling’en; WANG; Shengkui; CHENG; Qingwen; MIN; Lu; HE


    In recent years, agro-tourism has sprung up all over the country, and has gradually become a new form of agricultural business and a new force of tourism development. The development of agro-tourism plays an important role in enriching the agricultural industry forms, increasing farmers’ income, promoting the optimization and upgrading of rural industrial structure, and expanding the field of the tourism section. This paper firstly introduces domestic and foreign agro-tourism development and current research situations. Then it analyses the development background of China’s agro-tourism from the perspective of market demand, urbanization and transformation of rural economic structure. Based on analysis, it summarizes models of driving force of China’s agro-tourism: regional traffic driven, city driven, scenic spot driven, and monopolistic resource-driven. According to these four driving force types, development strategies are put forward: Characteristic product development for regional traffic driven model; in-depth theme development for city driven model; interactive development for scenic spot driven model; brand development for resource driven model; priority development for integrated driven model. It is expected to provide reference and guidance for healthy and sustainable development of China’s agro-tourism.

  14. Non primary standards SIM force comparison up to 10 kn

    Claudia Santo


    Full Text Available This force comparison was performed among IDIC (Chile, LATU (Uruguay and CENAM (Mexico, national laboratories within the Interamerican Metrology System (SIM region. Each laboratory used its national standard for the established measuring range. The comparison started in August 2002 and finished in September 2004. This comparison is the second part of a SIM primary standards comparison carried out with the participation of INMETRO (Brazil, INTI (Argentina and SIC (Colombia, having CENAM as pilot laboratory, (SIM comparison number SIM 7.7. This comparison has an overlap with the force steps used in the CIPM Key Comparison CCM.F-K1.a and CCM.F-K1.b., force points 5 kN and 10 kN.The objective of the comparison was to estimate the level of agreement for the realization of the quantity force and the uncertainty associated to its measurement in the range up to 10 kN. Two transducers (load cells were used as transfer standards, to obtain its maximum accuracy, thecomparison range was selected from 4 kN to 10 kN (starting at 40% of the full load cells range. The results obtained by the participating laboratories were in agreement according to the analysis of comparability performed by the normalized error equation and the Youden plot techniques used.

  15. Remote sensing monitoring and driving force analysis to forest and greenbelt in Zhuhai

    Yuliang Qiao, Pro.

    As an important city in the southern part of Chu Chiang Delta, Zhuhai is one of the four special economic zones which are opening up to the outside at the earliest in China. With pure and fresh air and trees shading the street, Zhuhai is a famous beach port city which is near the mountain and by the sea. On the basis of Garden City, the government of Zhuhai decides to build National Forest City in 2011, which firstly should understand the situation of greenbelt in Zhuhai in short term. Traditional methods of greenbelt investigation adopt the combination of field surveying and statistics, whose efficiency is low and results are not much objective because of artificial influence. With the adventure of the information technology such as remote sensing to earth observation, especially the launch of many remote sensing satellites with high resolution for the past few years, kinds of urban greenbelt information extraction can be carried out by using remote sensing technology; and dynamic monitoring to spatial pattern evolvement of forest and greenbelt in Zhuhai can be achieved by the combination of remote sensing and GIS technology. Taking Landsat5 TM data in 1995, Landsat7 ETM+ data in 2002, CCD and HR data of CBERS-02B in 2009 as main information source, this research firstly makes remote sensing monitoring to dynamic change of forest and greenbelt in Zhuhai by using the combination of vegetation coverage index and three different information extraction methods, then does a driving force analysis to the dynamic change results in 3 months. The results show: the forest area in Zhuhai shows decreasing tendency from 1995 to 2002, increasing tendency from 2002 to 2009; overall, the forest area show a small diminution tendency from 1995 to 2009. Through the comparison to natural and artificial driving force, the artificial driving force is the leading factor to the change of forest and greenbelt in Zhuhai. The research results provide a timely and reliable scientific basis

  16. Supersaturation is a major driving force for protein aggregation in neurodegenerative diseases

    Ciryam, Prajwal; Kundra, Rishika; Morimoto, Richard I.; Dobson, Christopher M.; Vendruscolo, Michele


    The solubility of proteins is an essential requirement for their function. Yet these ubiquitous molecules can undergo aggregation when the protein homeostasis system becomes impaired. Here we ask which is the driving force for protein aggregation in the cellular environment. Emerging evidence suggests that this phenomenon arises because the native states of many proteins are inherently metastable as their cellular concentrations exceed their critical values. Such `supersaturated' proteins are strongly driven towards aggregation, and are over-represented in specific biochemical pathways associated with neurodegenerative conditions. These observations suggest that effective therapeutic approaches to combat neurodegenerative diseases could be aimed at enhancing the ability of the cell to maintain protein solubility. PMID:25636813

  17. Determination of Optimal Energy Efficient Separation Schemes based on Driving Forces

    Bek-Pedersen, Erik; Gani, Rafiqul; Levaux, O.


    A new integrated approach for synthesis, design and operation of separation schemes is presented. This integrated approach is based on driving forces that promote the desired separation for different separation techniques. A set of algorithms needed by the integrated approach for sequencing...... and design of distillation columns and for generating hybrid separation schemes are presented. The main feature of these algorithms is that they provide a 'visual' solution that also appears to be near optimal in terms of energy consumption. Several illustrative examples highlighting the application...

  18. Neutron single-particle strength in silicon isotopes: Constraining the driving forces of shell evolution

    Stroberg, S R; Tostevin, J A; Bader, V M; Baugher, T; Bazin, D; Berryman, J S; Brown, B A; Campbell, C M; Kemper, K W; Langer, C; Lunderberg, E; Lemasson, A; Noji, S; Otsuka, T; Recchia, F; Walz, C; Weisshaar, D; Williams, S


    Shell evolution is studied in the neutron-rich silicon isotopes 36,38,40 Si using neutron single-particle strengths deduced from one-neutron knockout reactions. Configurations involving neutron excita- tions across the N = 20 and N = 28 shell gaps are quantified experimentally in these rare isotopes. Comparisons with shell model calculations show that the tensor force, understood to drive the col- lective behavior in 42 Si with N = 28, is already important in determining the structure of 40 Si with N = 26. New data relating to cross-shell excitations provide the first quantitative support for repulsive contributions to the cross-shell T = 1 interaction arising from three-nucleon forces.

  19. Three-quark interaction: The driving force in the inhomogeneous evolution equations

    Bartnik, E.A.; Namyslowski, J.M.


    Using perturbative QCD on the light cone (A/sub +/ = 0 gauge), and the Brodsky-Lepage collinear projection, we make a partial-wave projection (in the l/sub z/ component) of the Weinberg equation, and find a set of evolution equations for distribution amplitudes. For l/sub z/not =0 our equations are inhomogeneous, and their solutions show an increasing QCD perturbative effect for the currently available momentum transfers. The driving force of the inhomogenous evolution equations is a three-quark irreducible interaction, which gives terms approx.(1-x)/sup 3/ in the proton's deep-inelastic structure function, breaks the SU(6) symmetry, and contributes to the deviation of the d/u ratio for proton from the value 1/2. That force couples a qq-bar pair to one transverse gluon and one Coulomb gluon.

  20. Exodus of male physicians from primary care drives shift to specialty practice.

    Tu, Ha T; O'Malley, Ann S


    An exodus of male physicians from primary care is driving a marked shift in the U.S. physician workforce toward medical-specialty practice, according to a national study by the Center for Studying Health System Change (HSC). Two factors have helped mask the severity of the shift--a growing proportion of female physicians, who disproportionately choose primary care, and continued reliance on international medical graduates (IMGs), who now account for nearly a quarter of all U.S. primary care physicians. Since 1996-97, a 40 percent increase in the female primary care physician supply has helped to offset a 16 percent decline in the male primary care physician supply relative to the U.S. population. At the same time, primary care physicians' incomes have lost ground to both inflation and medical and surgical specialists' incomes. And women in primary care face a 22 percent income gap relative to men, even after accounting for differing characteristics. If real incomes for primary care physicians continue to decline, there is a risk that the migration of male physicians will intensify and that female physicians may begin avoiding primary care--trends that could aggravate a predicted shortage of primary care physicians.

  1. Proton-coupled electron transfers: pH-dependent driving forces? Fundamentals and artifacts.

    Bonin, Julien; Costentin, Cyrille; Robert, Marc; Routier, Mathilde; Savéant, Jean-Michel


    Besides its own interest, tryptophan oxidation by photogenerated Ru complexes is one of the several examples where concerted proton-electron transfer (CPET) to water as proton acceptor endowed with a pH-dependent driving force has been invoked to explain the data. Since this notion is contrary to the very basic principles of chemical physics, it was interesting to attempt uncovering the source of this contradiction with an easily accessible substrate. Careful examination of the oxidation of the tryptophan (ethyl ester derivative) bearing a NH3(+)/NH2 group showed that there is no trace of such an unconventional H2O-CPET with a pH-dependent driving force. The reaction mechanism simply consists, with both the NH3(+) acid and NH2 basic forms of the tryptophan derivative, in a rate-determining electron-transfer step followed by deprotonation steps. The same is true with the ethyl ester-methyl amide derivative of tryptophan, whose behavior is even simpler since the molecule does not bear an acid-base group. No such unconventional H2O-CPET was found with phenol, another easily accessible substrate. It may thus be inferred that the same applies to less easily available systems in which electron transfer occurs intramolecularly. These observations help to rid the road of such artificial obstacles and improve present models of H2O-CPET reactions, a landmark towards the understanding of the role of water chains in natural systems.

  2. On arable land changes in Shandong Province and their driving forces


    The decrease of total cultivated area and the lower per capitaavailable arable land resource are now serious problems in Shandong Province, a major agricultural province in China. These problems will become more serious along with the further development of economy. In this paper,based on the statistical information at provincial and county levels, the changes of arable land in Shandong Province and their driving forces during the last 50 years are analyzed. The general changing trends of arable land and per capita available arable land are reducing, and the trends of decrease will continue when the economy is developing. The result of GIS spatial analysis shows that the change of the arable land use in Shandong Province has a regional difference. Eight variables having influences on cultivated land change are analyzed by principal component analysis. The results show that the dynamic development of economy, pressure of social system and progress of scientific techniques in agriculture are the main causes for cultivated land reduction. The principal factors which can be considered as driving forces for arable land change include per capita net living space, total population and per ha grain yield. By using regressive equation, along with analysis on population growth and economic development, cultivated areas in Shandong Province in 2005 and 2010 are predicted respectively. The predicted cultivated areas in Shandong will be 6435.47 thousand hain 2005 and 6336.23 thousand ha in 2010 respectively.

  3. Dissolution Condensation Mechanism of Stress Corrosion Cracking in Liquid Metals: Driving Force and Crack Kinetics

    Glickman, Evgeny E.


    Stress corrosion cracking (SCC) in aqueous solution is driven by exothermic reactions of metal oxidation. This stimulus, as well as classical mechanisms of SCC, does not apply to SCC in liquid metals (LMs). In the framework of the dissolution-condensation mechanism (DCM), we analyzed the driving force and crack kinetics for this nonelectrochemical mode of SCC that is loosely called "liquid metal embrittlement" (LME). According to DCM, a stress-induced increase in chemical potential at the crack tip acts as the driving force for out-of-the-tip diffusion mass transfer that is fast because diffusion in LMs is very fast and surface energy at the solid-liquid interface is small. In this article, we review two versions of DCM mechanism, discuss the major physics behind them, and develop DCM further. The refined mechanism is applied then to the experimental data on crack velocity V vs stress intensity factor, the activation energy of LME, and alloying effects. It is concluded that DCM provides a good conceptual framework for analysis of a unified kinetic mechanism of LME and may also contribute to SCC in aqueous solutions.

  4. Driving forces and barriers for environmental technology development; Drivkrefter og barrierer for utvikling av miljoeteknologi



    Driving forces and barriers behind development and usage of environmental technology is discussed, and also whether there are certain characteristics related to environmental innovations compared to other innovations in general. The development of environmental technology is in principle dominated by the same drivers and barriers as any other technology, but the order and strength of the various factors may be different. This examination as well as other empirical studies shows that regulations play a greater part for environmental technology than 'pure market forces'. To many participants it is important to be one step ahead of the regulations, i.e. the expected regulations are equally important as the factual ones in driving the technology development. Players in the business community express that it is important that the authorities cooperate with them when introducing new regulations. This will increase acceptance for the regulations and facilitate the necessary adjustments. The most important barrier in the development and use of the technologies studied is probably the lack of demand.


    WANG Zhi-Qiang; CHEN Ming; WANG Dan-Dan; ZHANG Bai; ZHANG Shu-Qing


    Wetland is a kind of key natural resources. However, the wetlands have been shrinking rapidly in Sangjiang Plain and its functions have been degrading. These all hold back the sustainable development of human communities, and lead to great change in the land use /cover (LUCC), consequently caused global changes in climate, water cycling, etc.. Taken Fujin region as a case study, spatial and temporal dynamic processes of wetland and its driving forces were analyzed from 1954 to 2000 in this paper. It showed that the wetlands had been reduced from 52×104 ha to 11×104 ha in areas during the nearly 50 years . The percentage of wetland areas reduced from 61.27% to 12.39%. On the other hand, cultivated land increased from 22×104 ha to 60×104 ha in areas. The percentage of the areas increased from 25.31% to 70.45%. Further quantitative analysis of the wetland landscape conversion characteristics and the correlation analysis between the change of wetland areas and population increase were made. The results showed that 40×104 ha wetlands had been converted to cultivated land within half of a century; the correlation between the rate of wetland loss and that of population increased is nearly -0.922. So it was concluded that the main driving force of wetland shrinkage in Fujin region was the colonization of human being.

  6. Research on driving forces for rural settlement land changes in China

    CHEN Chun; FENG Chang-chun


    During the rapid urbanization period, the contradiction between demand for the construction land and the preservation of cultivated land for food security is getting more and more serious in China. With the urbanization the rural settlement land is increasing instead of decreasing. This paper aims at finding the driving forces for rural settlement land expansion. Based on land use change survey data (1996-2006) by the Ministry. of Land and Resources P. R. C., this paper finds that per capita area for rural settlement land is more than per capita area for city township and industrial land in each province except Tibet. Besides, rural settlement land area and per capita rural settlement land area are increasing while the rural population is decreasing in most provinces. The main problems of rural settlement land use are low efficiency, high vacancy rate, chaotic layout and illegal occupancy. Then the driving forces for rural settlement land expansion, including economic development family income, family scale, psychological factors, urbanization, transportation, lack of planning, limited circulation of dwelling-house land and imperfect social security, are explored based on above analysts. Finally, policy recommendations, in view of different influencing factors, are put forward to control the disorder expansion of rural settlement land.

  7. Driving forces behind the construction of an eco-compensation mechanism for wetlands in China

    Wang, Changhai


    This research revealed important driving forces behind the construction of an eco-compensation mechanism for wetlands (DFEMW) in China. Using China's provincial panel data from 1978 to 2008, a fixed-effects model was used to analyze the impacts of agricultural production systems on wetlands. We identified three DFEMW as follows: the change of wetland resources and protection measures in China; declaration and implementation of the provincial Wetland Protection Ordinance; and wetland degradation by agricultural production systems, which necessitated the establishment of a wetland eco-compensation mechanism. In addition to the DFEMW, a significant positive correlation between wetland area and both rural population and gross agricultural production was identified, in addition to a negative correlation with chemical fertilizer usage, reservoir storage capacity, and irrigation area. The underlying reasons for the serious degradation and inadequate protection of wetlands were market failure and government failure; these were the driving forces behind the need to establish a wetland eco-compensation mechanism. From a governmental perspective, it has been difficult to rectify market failures in resource distribution and thus to prevent wetland degradation. Factors include conflicts of interest, lack of investment, effective special laws, a simple means to protect wetlands, and a multidisciplinary management system. Therefore, the key factor is the coordination of interest relationships between those who utilize wetlands and those who seek to minimize wetland degradation and effectively protect wetlands.

  8. Driving forces behind the Chinese public's demand for improved environmental safety.

    Wen, Ting; Wang, Jigan; Ma, Zongwei; Bi, Jun


    Over the past decades, the public demand for improved environmental safety keeps increasing in China. This study aims to assess the driving forces behind the increasing public demand for improved environmental safety using a provincial and multi-year (1995, 2000, 2005, 2010, and 2014) panel data and the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The potential driving forces investigated included population size, income levels, degrees of urbanization, and educational levels. Results show that population size and educational level are positively (Pdemand for improved environmental safety. No significant impact on demand was found due to the degree of urbanization. For the impact due to income level, an inverted U-shaped curve effect with the turning point of ~140,000 CNY GDP per capita is indicated. Since per capita GDP of 2015 in China was approximately 50,000 CNY and far from the turning point, the public demand for improved environmental safety will continue rising in the near future. To meet the increasing public demand for improved environmental safety, proactive and risk prevention based environmental management systems coupled with effective environmental risk communication should be established. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Salticid predation as one potential driving force of ant mimicry in jumping spiders.

    Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I-Min


    Many spiders possess myrmecomorphy, and species of the jumping spider genus Myrmarachne exhibit nearly perfect ant mimicry. Most salticids are diurnal predators with unusually high visual acuity that prey on various arthropods, including conspecifics. In this study, we tested whether predation pressure from large jumping spiders is one possible driving force of perfect ant mimicry in jumping spiders. The results showed that small non-ant-mimicking jumping spiders were readily treated as prey by large ones (no matter whether heterospecific or conspecific) and suffered high attack and mortality rates. The size difference between small and large jumping spiders significantly affected the outcomes of predatory interactions between them: the smaller the juvenile jumping spiders, the higher the predation risk from large ones. The attack and mortality rates of ant-mimicking jumping spiders were significantly lower than those of non-ant-mimicking jumping spiders, indicating that a resemblance to ants could provide protection against salticid predation. However, results of multivariate behavioural analyses showed that the responses of large jumping spiders to ants and ant-mimicking salticids differed significantly. Results of this study indicate that predation pressure from large jumping spiders might be one selection force driving the evolution of nearly perfect myrmecomorphy in spiders and other arthropods.

  10. Analysis of two phase mass transfer by logarithmic driving force based on chemical thermodynamics

    Nabeshima, Masahiro (Sumitomo Metal Mining Co. Ltd., Tokyo (Japan))


    In the Purex solvent extraction process in the reprocessing of spent fuel, the concentration of separated composition such as U changes continuously from very high condition to trace level. Also in most cases, water phase and organic phase continuously come in contact by counter flow operation. In this research, by the method of circulating organic phase between single liquid drop column and mixing tank, the extraction behavior of Nd and nitric acid in H[sub 2]O-NaNO[sub 3]/HNO[sub 3]-Nd(NO[sub 3])[sub 3]-100% TBP system was traced continuously, and the results of measurement and analysis are reported. The experimental equipment and the experimental condition are shown. As the driving force for two-phase mass transfer, that having chemical thermodynamic basis was introduced. It is considered that this driving force is effective for the kinetic analysis of mass transfer phenomena. Hereafter, it is necessary to confirm the more strict treatment using activity and the applicability to two-phase mass transfer phenomena. (K.I.).

  11. Directed Self-Assembly of sub-10 nm Particles: Role of Driving Forces and Template Geometry in Packing and Ordering.

    Mehraeen, Shafigh; Asbahi, Mohamed; Fuke, Wang; Yang, Joel K W; Cao, Jianshu; Tan, Mei Chee


    By comparing the magnitude of forces, a directed self-assembly mechanism has been suggested previously in which immersion capillary is the only driving force responsible for packing and ordering of nanoparticles, which occur only after the meniscus recedes. However, this mechanism is insufficient to explain vacancies formed by directed self-assembly at low particle concentrations. Utilizing experiments, and Monte Carlo and Brownian dynamics simulations, we developed a theoretical model based on a new proposed mechanism. In our proposed mechanism, the competing driving forces controlling the packing and ordering of sub-10 nm particles are (1) the repulsive component of the pair potential and (2) the attractive capillary forces, both of which apply at the contact line. The repulsive force arises from the high particle concentration, and the attractive force is caused by the surface tension at the contact line. Our theoretical model also indicates that the major part of packing and ordering of nanoparticles occurs before the meniscus recedes. Furthermore, utilizing our model, we are able to predict the various self-assembly configurations of particles as their size increases. These results lay out the interplay between driving forces during directed self-assembly, motivating a better template design now that we know the importance and the dominating driving forces in each regime of particle size.

  12. Human health and the water environment: using the DPSEEA framework to identify the driving forces of disease.

    Gentry-Shields, Jennifer; Bartram, Jamie


    There is a growing awareness of global forces that threaten human health via the water environment. A better understanding of the dynamic between human health and the water environment would enable prediction of the significant driving forces and effective strategies for coping with or preventing them. This report details the use of the Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA) framework to explore the linkage between water-related diseases and their significant driving forces. The DPSEEA frameworks indicate that a select group of driving forces, including population growth, agriculture, infrastructure (dams and irrigation), and climate change, is at the root cause of key global disease burdens. Construction of the DPSEEA frameworks also allows for the evaluation of public health interventions. Sanitation was found to be a widely applicable and effective intervention, targeting the driver/pressure linkage of most of the water-related diseases examined. Ultimately, the DPSEEA frameworks offer a platform for constituents in both the health and environmental fields to collaborate and commit to a common goal targeting the same driving forces.

  13. Application of laser ranging and VLBI data to a study of plate tectonic driving forces. [finite element method

    Solomon, S. C.


    The measurability of changes in plate driving or resistive forces associated with plate boundary earthquakes by laser rangefinding or VLBI is considered with emphasis on those aspects of plate forces that can be characterized by such measurements. Topics covered include: (1) analytic solutions for two dimensional stress diffusion in a plate following earthquake faulting on a finite fault; (2) two dimensional finite-element solutions for the global state of stress at the Earth's surface for possible plate driving forces; and (3) finite-element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting.

  14. The role of biotic forces in driving macroevolution: beyond the Red Queen

    Voje, Kjetil L.; Holen, Øistein H.; Liow, Lee Hsiang; Stenseth, Nils Chr.


    A multitude of hypotheses claim that abiotic factors are the main drivers of macroevolutionary change. By contrast, Van Valen's Red Queen hypothesis is often put forward as the sole representative of the view that biotic forcing is the main evolutionary driver. This imbalance of hypotheses does not reflect our current knowledge: theoretical work demonstrates the plausibility of biotically driven long-term evolution, whereas empirical work suggests a central role for biotic forcing in macroevolution. We call for a more pluralistic view of how biotic forces may drive long-term evolution that is compatible with both phenotypic stasis in the fossil record and with non-constant extinction rates. Promising avenues of research include contrasting predictions from relevant theories within ecology and macroevolution, as well as embracing both abiotic and biotic proxies while modelling long-term evolutionary data. By fitting models describing hypotheses of biotically driven macroevolution to data, we could dissect their predictions and transcend beyond pattern description, possibly narrowing the divide between our current understanding of micro- and macroevolution. PMID:25948685

  15. Talin2-mediated traction force drives matrix degradation and cell invasion.

    Qi, Lei; Jafari, Naser; Li, Xiang; Chen, Zaozao; Li, Liqing; Hytönen, Vesa P; Goult, Benjamin T; Zhan, Chang-Guo; Huang, Cai


    Talin binds to β-integrin tails to activate integrins, regulating cell migration, invasion and metastasis. There are two talin genes, TLN1 and TLN2, encoding talin1 and talin2, respectively. Talin1 regulates focal adhesion dynamics, cell migration and invasion, whereas the biological function of talin2 is not clear and, indeed, talin2 has been presumed to function redundantly with talin1. Here, we show that talin2 has a much stronger binding to β-integrin tails than talin1. Replacement of talin2 Ser339 with Cys significantly decreased its binding to β1-integrin tails to a level comparable to that of talin1. Talin2 localizes at invadopodia and is indispensable for the generation of traction force and invadopodium-mediated matrix degradation. Ablation of talin2 suppressed traction force generation and invadopodia formation, which were restored by re-expressing talin2 but not talin1. Furthermore, re-expression of wild-type talin2 (but not talin2(S339C)) in talin2-depleted cells rescued development of traction force and invadopodia. These results suggest that a strong interaction of talin2 with integrins is required to generate traction, which in turn drives invadopodium-mediated matrix degradation, which is key to cancer cell invasion. © 2016. Published by The Company of Biologists Ltd.

  16. Unraveling the genetic driving forces enabling antibiotic resistance at the single cell level

    Bos, Julia

    Bacteria are champions at finding ways to quickly respond and adapt to environments like the human gut, known as the epicentre of antibiotic resistance. How do they do it? Combining molecular biology tools to microfluidic and fluorescence microscopy technologies, we monitor the behavior of bacteria at the single cell level in the presence of non-toxic doses of antibiotics. By tracking the chromosome dynamics of Escherichia coli cells upon antibiotic treatment, we examine the changes in the number, localization and content of the chromosome copies within one cell compartment or between adjacent cells. I will discuss how our work pictures the bacterial genomic plasticity as a driving force in evolution and how it provides access to the mechanisms controlling the subtle balance between genetic diversity and stability in the development of antibiotic resistance.

  17. Greatest Happiness Principle in a Complex System: Maximisation versus Driving Force

    Katalin Martinás


    Full Text Available From philosophical point of view, micro-founded economic theories depart from the principle of the pursuit of the greatest happiness. From mathematical point of view, micro-founded economic theories depart from the utility maximisation program. Though economists are aware of the serious limitations of the equilibrium analysis, they remain in that framework. We show that the maximisation principle, which implies the equilibrium hypothesis, is responsible for this impasse. We formalise the pursuit of the greatest happiness principle by the help of the driving force postulate: the volumes of activities depend on the expected wealth increase. In that case we can get rid of the equilibrium hypothesis and have new insights into economic theory. For example, in what extent standard economic results depend on the equilibrium hypothesis?

  18. The Impact of Evolutionary Driving Forces on Human Complex Diseases: A Population Genetics Approach

    Amr T. M. Saeb


    Full Text Available Investigating the molecular evolution of human genome has paved the way to understand genetic adaptation of humans to the environmental changes and corresponding complex diseases. In this review, we discussed the historical origin of genetic diversity among human populations, the evolutionary driving forces that can affect genetic diversity among populations, and the effects of human movement into new environments and gene flow on population genetic diversity. Furthermore, we presented the role of natural selection on genetic diversity and complex diseases. Then we reviewed the disadvantageous consequences of historical selection events in modern time and their relation to the development of complex diseases. In addition, we discussed the effect of consanguinity on the incidence of complex diseases in human populations. Finally, we presented the latest information about the role of ancient genes acquired from interbreeding with ancient hominids in the development of complex diseases.

  19. Chronic inflammation-related DNA damage response: a driving force of gastric cardia carcinogenesis.

    Lin, Runhua; Xiao, Dejun; Guo, Yi; Tian, Dongping; Yun, Hailong; Chen, Donglin; Su, Min


    Gastric cardia cancer (GCC) is a highly aggressive disease associated with chronic inflammation. To investigate the relationship between DNA damage response (DDR) and chronic inflammation, we collected 100 non-tumor gastric cardia specimens of Chaoshan littoral, a high-risk region for esophageal and gastric cardia cancer. A significantly higher proportion of severe chronic inflammation was found in dysplastic epithelia (80.9%) in comparison with that in non-dysplastic tissues (40.7%) (Pchronic inflammation degrees from normal to severe inflammation (Pchronic inflammation-related DNA damage response may be a driving force of gastric cardia carcinogenesis. Based on these findings, DNA damage response in non-malignant tissues may become a promising biomedical marker for predicting malignant transformation in the gastric cardia.

  20. Synchronized aromaticity as an enthalpic driving force for the aromatic Cope rearrangement.

    Babinski, David J; Bao, Xiaoguang; El Arba, Marie; Chen, Bo; Hrovat, David A; Borden, Weston Thatcher; Frantz, Doug E


    We report herein experimental and theoretical evidence for an aromatic Cope rearrangement. Along with several successful examples, our data include the first isolation and full characterization of the putative intermediate that is formed immediately after the initial [3,3] sigmatropic rearrangement. Calculations at the B3LYP/6-31G(d) level of theory predict reaction energy barriers in the range 22-23 kcal/mol for the [3,3]-rearrangement consistent with the exceptionally mild reaction conditions for these reactions. The experimental and computational results support a significant enthalpic contribution of the concomitant pyrazole ring formation that serves as both a kinetic and thermodynamic driving force for the aromatic Cope rearrangement.

  1. Stress-triggered atavistic reprogramming (STAR) addiction: driving force behind head and neck cancer?

    Masuda, Muneyuki; Wakasaki, Takahiro; Toh, Satoshi


    Recent results of the Cancer Genome Atlas on head and neck squamous cell carcinoma (HNSCC) revealed that HNSCC lacked predominant gain-of-function mutations in oncogenes, whereas an essential role for epigenetics in oncogenesis has become apparent. In parallel, it has gained general acceptance that cancer is considered as complex adaptive system, which evolves responding environmental selective pressures. This somatic evolution appears to proceed concurrently with the acquisition of an atavistic pluripotent state (i.e., "stemness"), which is inducible by intrinsic epigenetic reprogramming program as demonstrated by induced pluripotent stem (iPS) cells. This Nobel prize-winning discovery has markedly accelerated and expanded cancer stem cell research from the point of epigenetic reprogramming. Taken together, we hypothesize that stress-triggered atavistic reprogramming (STAR) may be the major driving force of HNSCC evolution. In this perspective, we discuss the possible mechanisms of STAR in HNSCC, focusing on recent topics of epigenetic reprogramming in developmental and cancer cell biology.

  2. Driving force analysis of the agricultural water footprint in China based on the LMDI method.

    Zhao, Chunfu; Chen, Bin


    China's water scarcity problems have become more severe because of the unprecedented economic development and population explosion. Considering agriculture's large share of water consumption, obtaining a clear understanding of Chinese agricultural consumptive water use plays a key role in addressing China's water resource stress and providing appropriate water mitigation policies. We account for the Chinese agricultural water footprint from 1990 to 2009 based on bottom up approach. Then, the underlying driving forces are decomposed into diet structure effect, efficiency effect, economic activity effect, and population effect, and analyzed by applying a log-mean Divisia index (LMDI) model. The results reveal that the Chinese agricultural water footprint has risen from the 94.1 Gm3 in 1990 to 141 Gm3 in 2009. The economic activity effect is the largest positive contributor to promoting the water footprint growth, followed by the population effect and diet structure effect. Although water efficiency improvement as a significant negative effect has reduced overall water footprint, the water footprint decline from water efficiency improvement cannot compensate for the huge increase from the three positive driving factors. The combination of water efficiency improvement and dietary structure adjustment is the most effective approach for controlling the Chinese agricultural water footprint's further growth.

  3. Vegetation Dynamics and Associated Driving Forces in Eastern China during 1999–2008

    Jian Peng


    Full Text Available Vegetation is one of the most important components of the terrestrial ecosystem and, thus, monitoring the spatial and temporal dynamics of vegetation has become the key to exploring the basic process of the terrestrial ecosystem. Vegetation change studies have focused on the relationship between climatic factors and vegetation dynamics. However, correlations among the climatic factors always disturb the results. In addition, the impact of anthropogenic activities on vegetation dynamics was indeterminate. Here, vegetation dynamics in 14 provinces in Eastern China over a 10-year period was quantified to determine the driving mechanisms relating to climate and anthropogenic factors using partial correlation analysis. The results showed that from 1999 to 2008, the vegetation density increased in the whole, with spatial variations. The vegetation improvement was concentrated in the Yangtze River Delta, with the vegetation degradation concentrated in the other developed areas, such as Beijing-Tianjin-Hebei Region and the Pearl River Delta. The annual NDVI changes were mainly driven by temperature in Northeast China and the Pearl River Delta, and by precipitation in the Bohai Rim; while in the Yangtze River Delta, the driving forces of temperature and precipitation almost equaled each other.  Furthermore, the impact of anthropogenic activities on vegetation dynamics had accumulative effects in the time series, and had a phase effect on the vegetation change trend.

  4. Analysis on Electromagnetic Characteristics of Research Reactor Control Rod Drive Mechanism for Thrust Force Improvement

    Huh, Hyung; Choi, Myoung Hwan; Yu, Je Yong; Cho, Yeong Garp; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The control rod drive mechanism (CRDM) is the part of reactor regulating system (RRS), which is located in the reactor pool top or the room below the reactor pool. The function of the CRDM is to insert, withdraw or maintain neutron absorbing material (control rod) at any required position within the reactor core, in order to the reactivity of the core. There are so many kinds of CRDM, such as magnetic-jack type, hydraulic type, rack and pinion type, chain type and linear or rotary step motor and so on. As a part of a new project, we are investigating the movable coil electromagnetic drive mechanism (MCEDM) which is new scheme for the reactor control rod adopted by China Advanced Research Reactor (CARR). To have a better knowledge of the electromagnetic and magnetic characteristics, numerical models of MCEDM are proposed. Especially in order to achieve improved thrust force, numerical magnetic field calculations for various kinds of magnetic and electromagnetic configuration have been performed. As a result, we present the improved design of MCEDM for research reactor

  5. Spatial heterogeneity of the driving forces of cropland change in China

    LIU; Xuhua; WANG; Jinfeng; LIU; Mingliang; MENG; Bin


    By using digital satellite remote sensing data acquired in 1987―1989 and 1999―2000 and GIS combined with the natural and socio-economic data, this paper drew an integrated zonation of the cropland change and its driving forces in China. The results indicated that the cropland change in the study period was constrained by geographical factors and driven by climate change as well as socio-economic system. Moreover, the regional differences of the drivers for cropland change were significant. In the midwest of China, natural condition changes and geographical background were the main constraints and drivers, while in Eastern China, social and economic changes and economic policies were the main driving forces. The cropland loss was nationwide. The dominant factors to cause this decrease included buildup of developing area to attract foreign capital and technologies, changes of industry structure due to urban influence, the change of employment notions thanks to living standard improvement, rapid urbanization due to the expansion of cities and towns, the diminished farming net income partly because of the global warming effects, and the rapid economic growth stimulated by the convenient transportation system. These factors interact and interdepend with each other to cause the cropland loss in China recently. The reasons for the increase of cropland were primarily the cultivation and deforestation by the farmers who want to increase income. This study on the mechnism of LUCC relied on the cropland change integrated classification considering the natural or human factors both inside and outside the region, which provides a new approach to study the integrated regionalization and LUCC mechanism.

  6. Driving forces for import of waste for energy recovery in Sweden.

    Olofsson, Mattias; Sahlin, Jenny; Ekvall, Tomas; Sundberg, Johan


    Between 1996 and 2002, the Swedish import of so-called yellow waste for energy recovery increased. The import mainly consisted of separated wood waste and mixes of used wood and paper and/or plastics that was combusted in district heat production plants (DHPPs). Some mixed waste was imported to waste incineration plants for energy recovery (10% of the import of yellow waste for energy recovery in 2002). The import came primarily from Germany, the Netherlands, Norway, Denmark and Finland. We identified six underlying driving forces for this recent increase of imported waste which are outlined and their interactive issues discussed. --The energy system infrastructure, which enables high energy recovery in Sweden. --The energy taxation, where high Swedish taxes on fossil fuels make relatively expensive solid biofuels the main alternative for base load production of district heat. --The quality of the waste-derived fuels, which has been higher in the exporting countries than in Sweden. --The bans on landfilling within Europe and the shortage of waste treatment capacity. --Taxes on waste management in Europe. --Gate fee differences between exporting countries and Sweden. In the future, the overall strength of these driving forces will probably be weakened. A Swedish tax on waste incineration is being investigated. In other European countries, the ambition to reach the Kyoto targets and increase the renewable electricity production could improve the competitiveness of waste-derived fuels in comparison with fossil fuels. Swedish DHPPs using waste-derived fuels will experience higher costs after the Waste Incineration Directive is fully implemented. The uncertainty about European waste generation and treatment capacity, however, might have a large influence on the future gate fees and thus also on the yellow waste import into Sweden.

  7. Quantitative attribution of major driving forces on soil organic carbon dynamics

    Wu, Yiping; Liu, Shuguang; Tan, Zhengxi


    Soil organic carbon (SOC) storage plays a major role in the global carbon cycle and is affected by many factors including land use/management changes (e.g., biofuel production-oriented changes). However, the contributions of various factors to SOC changes are not well understood and quantified. This study was designed to investigate the impacts of changing farming practices, initial SOC levels, and biological enhancement of grain production on SOC dynamics and to attribute the relative contributions of major driving forces (CO2 enrichment and farming practices) using a fractional factorial modeling design. The case study at a crop site in Iowa in the United States demonstrated that the traditional corn-soybean (CS) rotation could still accumulate SOC over this century (from 4.2 to 6.8 kg C/m2) under the current condition; whereas the continuous-corn (CC) system might have a higher SOC sequestration potential than CS. In either case, however, residue removal could reduce the sink potential substantially. Long-term simulation results also suggested that the equilibrium SOC level may vary greatly (˜5.7 to ˜11 kg C/m2) depending on cropping systems and management practices, and projected growth enhancement could make the magnitudes higher (˜7.8 to ˜13 kg C/m2). Importantly, the factorial design analysis indicated that residue management had the most significant impact (contributing 49.4%) on SOC changes, followed by CO2 Enrichment (37%), Tillage (6.2%), the combination of CO2 Enrichment-Residue removal (5.8%), and Fertilization (1.6%). In brief, this study is valuable for understanding the major forces driving SOC dynamics of agroecosystems and informative for decision-makers when seeking the enhancement of SOC sequestration potential and sustainability of biofuel production, especially in the Corn Belt region of the United States.

  8. Driving forces for home-based reablement; a qualitative study of older adults' experiences.

    Hjelle, Kari Margrete; Tuntland, Hanne; Førland, Oddvar; Alvsvåg, Herdis


    As a result of the ageing population worldwide, there has been a growing international interest in a new intervention termed 'reablement'. Reablement is an early and time-limited home-based intervention with emphasis on intensive, goal-oriented and interdisciplinary rehabilitation for older adults in need of rehabilitation or at risk of functional decline. The aim of this qualitative study was to describe how older adults experienced participation in reablement. Eight older adults participated in semi-structured interviews. A qualitative content analysis was used as the analysis strategy. Four main themes emerged from the participants' experiences of participating in reablement: 'My willpower is needed', 'Being with my stuff and my people', 'The home-trainers are essential', and 'Training is physical exercises, not everyday activities'. The first three themes in particular reflected the participants' driving forces in the reablement process. Driving forces are intrinsic motivation in interaction with extrinsic motivation. Intrinsic motivation was based on the person's willpower and responsibility, and extrinsic motivation was expressed to be strengthened by being in one's home environment with 'own' people, as well as by the co-operation with the reablement team. The reablement team encouraged and supported the older adults to regain confidence in performing everyday activities as well as participating in the society. Our findings have practical significance for politicians, healthcare providers and healthcare professionals by contributing to an understanding of how intrinsic and extrinsic motivation influence reablement. Some persons need apparently more extrinsic motivational support also after the time-limited reablement period is completed. The municipal health and care services need to consider individualised follow-up programmes after the intensive reablement period in order to maintain the achieved skills to perform everyday activities and participate in

  9. Comparative Study on the Human Driving Force of Cultivated Land and Construction Land Use Change in Hubei Province,China


    Change trend of cultivated land and construction land in Hubei Province is analyzed.The years 1998-2003 are the reduction period of cultivated land;the years 2004-2007 are the increase period of cultivated land;the years 1988-2002 are the slow growth period of construction land;and the years of 2003 and 2007 are the increase period of construction land.Based on related social economic statistical data in 1988-2007,human driving forces on cultivated land and construction land in Hubei Province are analyzed quantitatively and comparatively by using SPSS software and mathematical statistics method.Result shows that driving force factors have negative driving effect on cultivated land,and positive driving effect on construction land.Driving force factors have significant differences of driving effects on cultivated land and construction land.Three principal components affecting the changes of cultivated land and construction land are policy,population and economic development level,and gap between urban and rural living standards.The three principal components have different degrees of sensitivity on the two land use types and the effects direction are reverse.The other factor driving abilities are relatively weak,and these factors have relatively stronger driving force on construction land than that on cultivated land.It is put forward that Hubei Province should implement rational allocation of land resources and scientific and rational use in order to ensure land security and to realize the sustainable development of regional economy and society based on the intensive land use,the planning policy constraints,and the agricultural and industrial production.

  10. Driving forces behind the increasing cardiovascular treatment intensity.A dynamic epidemiologic model of trends in Danish cardiovascular drug utilization.

    Kildemoes, Helle Wallach; Andersen, Morten

    to 619 DDD/TID from 1996 to 2005 (117%). Population ageing accounted for 22 percentage points. Treatment intensity with statins increased from 5 to 121 DDD/TID. Population ageing accounted for one eighth of this increase. Increasing incidence rates was the main driving force behind the growing statin......Background: In many Western countries cardiovascular treatment intensity (DDD/1000 inhabitants/day, DDD/TID) has grown substantially during the last decades. Changed drug utilization pattern - rather than population ageing - was hypothesized to be the main driving force behind the growth....... Objectives: To investigate the driving forces behind the increasing treatment prevalence of cardiovascular drugs, in particular statins, by means of a dynamic epidemiologic drug utilization model. Methods: Material: All Danish residents older than 20 years by January 1, 1996 (4.0 million inhabitants), were...

  11. Measuring cell adhesion forces of primary gastrulating cells from zebrafish using atomic force microscopy.

    Puech, Pierre-Henri; Taubenberger, Anna; Ulrich, Florian; Krieg, Michael; Muller, Daniel J; Heisenberg, Carl-Philipp


    During vertebrate gastrulation, progenitor cells of different germ layers acquire specific adhesive properties that contribute to germ layer formation and separation. Wnt signals have been suggested to function in this process by modulating the different levels of adhesion between the germ layers, however, direct evidence for this is still lacking. Here we show that Wnt11, a key signal regulating gastrulation movements, is needed for the adhesion of zebrafish mesendodermal progenitor cells to fibronectin, an abundant extracellular matrix component during gastrulation. To measure this effect, we developed an assay to quantify the adhesion of single zebrafish primary mesendodermal progenitors using atomic-force microscopy (AFM). We observed significant differences in detachment force and work between cultured mesendodermal progenitors from wild-type embryos and from slb/wnt11 mutant embryos, which carry a loss-of-function mutation in the wnt11 gene, when tested on fibronectin-coated substrates. These differences were probably due to reduced adhesion to the fibronectin substrate as neither the overall cell morphology nor the cell elasticity grossly differed between wild-type and mutant cells. Furthermore, in the presence of inhibitors of fibronectin-integrin binding, such as RGD peptides, the adhesion force and work were strongly decreased, indicating that integrins are involved in the binding of mesendodermal progenitors in our assay. These findings demonstrate that AFM can be used to quantitatively determine the substrate-adhesion of cultured primary gastrulating cells and provide insight into the role of Wnt11 signalling in modulating cell adhesion at the single cell scale.

  12. Geographic concentration and driving forces of agricultural land use in China

    Yuluan ZHAO; Xiubin LI; Liangjie XIN; Haiguang HAO


    Since the 1990s,China has entered the middle phase of urbanization which leads to the existence of significant geographic concentration of agricultural land use.The average value of regional concentration degree of ten representative crops in China was 59.03%,showing a high degree of geographic concentration in farming.Some typical agriculture provinces in farming have arisen.The degree of geographic concentration in farming has been enhanced,with the average degree of regional concentration often crops increasing considerably by 3.83% in 2009compared to that in 1990 (55.20%).The spatial growing center of farming was found to move westward and northward during 1990-2009.Meanwhile food production concentrated in the Northeast China and main producing area,and cash crops production concentrated in Northwest China.Off-farm employment of rural labor force,commercialization of agricultural product and regional comparative advantage are the main driving forces of geographic concentration of agricultural land use.Governmental policies with regional differences should be considered to promote further development of agriculture.

  13. Unbalance Force Analysis of Primary Pump Shaft in PGSFR

    Kim, Sungkyun; Koo, Gyeonghoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    In this paper, rotor-dynamic characteristics for the primary pump shaft were obtained. On the basis of the results, we decided to almost double the shaft diameter. By virtue of this design change, the revised design can be satisfied with the critical speed design criteria as well as can decrease a number of support bearings. In the results of unbalance analysis, it was figured that the maximum bearing deflections and loads are within the design criteria. All rotating shafts, even in the absence of external loads, have always eccentric distance due to the manufacturing deviations, material defects, and installation error. This unbalance mass resulting in the eccentric distance of the rotating structure causes resonance at critical speeds. The resonance is the state at which the harmonic loads are excited at their natural frequencies causing shafts to vibrate excessively. This vibration of large amplitude causes shafts to bend and twists significantly and leads to permanent failure. Hence, the determination of these rotor-dynamic characteristics of rotating shaft in the mechanical design stage is much important. In this paper following issues are addressed: - Describe how to calculate the unbalance force. - Predict the natural frequency variations and identify critical speeds within or near the operating speed range of a shaft for consideration of the unbalance bearing stiffness and damping. - Determine the available support positions of a pump shaft to avoid resonance within operating speed. - Perform an unbalance response analysis of a shaft in order to calculate shaft displacement and quantify the forces acting on the shaft support that are caused due to shaft unbalance.

  14. What drives interannual variability of hypoxia in Chesapeake Bay: Climate forcing versus nutrient loading?

    Li, Ming; Lee, Younjoo J.; Testa, Jeremy M.; Li, Yun; Ni, Wenfei; Kemp, W. Michael; Di Toro, Dominic M.


    Oxygen depletion in estuaries is a worldwide problem with detrimental effects on many organisms. Although nutrient loading has been stabilized for a number of these systems, seasonal hypoxia persists and displays large year-to-year variations, with larger hypoxic volumes in wetter years and smaller hypoxic volumes in drier years. Data analysis points to climate as a driver of interannual hypoxia variability, but nutrient inputs covary with freshwater flow. Here we report an oxygen budget analysis of Chesapeake Bay to quantify relative contributions of physical and biogeochemical processes. Vertical diffusive flux declines with river discharge, whereas longitudinal advective flux increases with river discharge, such that their total supply of oxygen to bottom water is relatively unchanged. However, water column respiration exhibits large interannual fluctuations and is correlated with primary production and hypoxic volume. Hence, the model results suggest that nutrient loading is the main mechanism driving interannual hypoxia variability in Chesapeake Bay.

  15. The Dynamic Change in the Total Arable Land and its Driving Forces in Tongling City of Anhui Province

    Yan; LI; Zhongxiang; YU


    According to Anhui Statistical Yearbook( 2003-2012) and the second national land survey data,this article analyzes the current situation of land use and the dynamic change in the total arable land in Tongling City. On the basis of this,using grey relational analysis,this article analyzes the driving forces for arable land changes in Tongling City. Studies show that population growth,the improvement of level of urbanization and the rapid development of the economy are the main driving forces for arable land changes. Based on the findings,the strategies are put forth in order to ensure the dynamic balance of total arable land.


    Roiban Roxana Nadina


    Full Text Available Change is a constant in everyday life confronting organizations to continuously adapt their strategy, structure, processes, and culture in order to survive and stay competitive on the market. Implementing organizational change is one of the most important skills required for managers and in the meantime the most difficult one. The forces driving change within an organization, that can be either external or internal, are those that propel a company forward towards change and in order to identify the need for change and make the proper changes, managers have to develop a tool that allows them to analyze how does the environment influence their business activities. A vision for change will clarify the directions in which the organization needs to move, starting from its current state and taking in consideration the existing opportunities and threats from the environment that allow to move to a future desired state. The purpose of this paper is to identify the concern for change in the Romanian small and medium sized enterprises by presenting and explaining the past and present influences of the main external forces that have determined the need for change in the last 3-5 years and to make recommendations about future possible changes that have to be performed by managers for a better harmonization with the environment. The research method used for this study is the interview on a sample that contains some of the most relevant SME’s from the western side of Romania, from different industries. We analyzed the main external forces that had an impact on the small and medium sized enterprises and how were they generating the need for organizational change, in order to see which present and future changes are required.

  17. Short primary linear drive designed for synchronous and induction operation mode with on-board energy storage

    Fernandes Neto, Tobias Rafael


    guide way (induction rail or stationary magnets), and the energy and information should be transmitted contactless to the active vehicle. Regarding the features of the material handling application, the short or long primary topology can be used. Short primary linear drives on passive track are advantageous in material handling applications, where high precision, moderate dynamic, very long track and closed paths are required. Nevertheless, depending on the requirements of the section, the costs can be reduced considerably by using a simple induction rail at the long transporting sections, instead of permanent magnets on the track. Therefore, in this thesis a combined operation of permanent magnet linear synchronous motor (PMLSM) and linear induction motor (LIM) is applied to operate the short primary as vehicle, avoiding adjustment or releasing of the material during the drive cycle. In summary, the passive track will consist of two section types: a high thrust force section (processing station) with PMLSM and a low thrust force section with LIM (transporting section). To the author's knowledge, using two operation modes (PMLSM / LIM) in the same drive is a new approach. A theoretical and experimental study was conducted to assess the feasibility of employing the short primary linear motor for a flexible manufacturing system, in which a contactless energy transmission provides the basic power and an ultracapacitor (UC) storage system provides the peak power. The system uses a bidirectional DC-DC converter between the ultracapacitor bank and the DC-link, to make sure that the ultracapacitor can store the braking energy and supply the peak power demanded by the active vehicle. A control strategy has been developed for controlling the ultracapacitor to deliver the peak of power, to charge, to protect against overvoltage and to recover the energy generated when the vehicle is braking. A control strategy for the transition between the two operation modes (PMLSM / LIM

  18. [Landscape pattern change of Dongzhai Harbour mangrove, South China analyzed with a patch-based method and its driving forces].

    Huang, Xing; Xin, Kun; Li, Xiu-zhen; Wang, Xue-ping; Ren, Lin-jing; Li, Xi-zhi; Yan, Zhong-zheng


    According to the interpreted results of three satellite images of Dongzhai Harbour obtained in 1988, 1998 and 2009, the changes of landscape pattern and the differences of its driving forces of mangrove forest in Dongzhai Harbour were analyzed with a patch-based method on spatial distribution dynamics. The results showed that the areas of mangrove forest in 1988, 1998 and 2009 were 1809.4, 1738.7 and 1608.2 hm2 respectively, which presented a trend of decrease with enhanced degree of landscape fragmentation. The transformations among different landscape types indicated that the mangrove, agricultural land and forest land were mainly changed into built-up land and aquaculture pond. The statistical results obtained from three different methods, i.e., accumulative counting, percentage counting and main transformation route counting, showed that natural factors were the main reason for the changes of patch number, responsible for 58.6%, 72.2% and 72.1% of patch number change, respectively, while the percentages of patch area change induced by human activities were 70.4%, 70.3% and 76.4%, respectively, indicating that human activities were the primary factors of the change of patch areas.

  19. Long-term dynamics in land resource use and the driving forces in the Beressa watershed, highlands of Ethiopia

    Amsalu Taye, A.; Stroosnijder, L.; Graaff, de J.


    Land degradation in the Ethiopian highlands is considered to be one of the major problems threatening agricultural development and food security in the country. However, knowledge about the forces driving the long-term dynamics in land resources use is limited. This research integrates biophysical i

  20. Rising electricity consumption: Driving forces and consequences. The case of rural Zanzibar

    Winther, Tanja [Centre for Development and the Environment (SUM), Univ. of Oslo (Norway)


    The paper addresses the current, rising electricity consumption in the southern, rural locality of Zanzibar and seeks to account for the range of driving forces behind people's changed practices. The author argues that these forces are, on the one hand, determined by the availability of new technologies and through global and national institutions and influences such as Islam, commercials and changes in the governmental sector (health, education). On the other hand, the paper explores the way such influences interplay with the internal dynamics related to increasing consumption. Through an analysis of the particular character and dynamics of social and cultural life in this region, the author explains why some practices are less likely to change than other practices. For example, people in Zanzibar keep electricity (freezers and stoves) at a distance from their food. By contrast, electric light is perceived as intimately related to education, as illustrated when school children are sent to school for night classes before important exams. To which extent may general approaches to the study of energy consumption draw on this empirical case from Zanzibar? In other contexts, the patterns of people's electricity use certainly differ. In terms of sustainable energy policies, each locality has a particular set of challenges and goals, which to varying degree may be related to poverty reduction and concern for the environment. Methodologically, however, the author argues that the phenomenon of energy consumption may be studied and understood within the same framework of analysis; one that pays attention to both external and internal dynamics, the material and social aspects of technologies and the importance of power relations, gender and negotiations.


    DING Sheng-yan; QIAN Le-xiang; CAO Xin-xiang; LI Shuang; LI Hao-min


    With the help of ARC/INFOR and ERDAS software, based on the information from forest resources distribution maps and TM images, four indices were chosen to analyze spatial pattern changes of forest landscape of Luoning County, Henan Province from 1983 to 1999. The results showed that: 1) The number and total area of patches were rapidly increased with time changes. The fragmentation degree of the landscape was increasing great-ly. 2) The area of some forest patch types, especially shrub forest, economic forest, Populus spp. Forest, Quercus spp. Forest, sparse forest, deserted grassland etc. Had been greatly changed. 3) The fragemation degree of each forest patch type became greater from 1983 to 1999.4) The transition probabilities of deserted forest, economic forest,Pi-nus tabulaeformis forest, Populus spp. Forest exceed 85%,Robinia pseuoacacia forest, deserted grassland, 65% and Quercus spp. Forest, non-forest, shrub forest had smaller ones, which were 26.5%, 29.1% and 45.3%, respec-tively. The main transition trends of various patches were non-forest and Quercus spp. Forest. During the course of transition, the types that 50% of area was remained were Quercus spp. Forest, non-forest and shrub forest. Accord-ing to above analyses, the main driving forces, such as the management policies, market economy factors and influ-ences of human activities etc. Were brought out.

  2. Driving forces of organic carbon spatial distribution in the tropical seascape

    Gillis, L. G.; Belshe, F. E.; Ziegler, A. D.; Bouma, T. J.


    An important ecosystem service of tropical coastal vegetation including seagrass beds and mangrove forests is their ability to accumulate carbon. Here we attempt to establish the driving forces for the accumulation of surface organic carbon in southern Thailand coastal systems. Across 12 sites we found that in line with expectations, seagrass beds (0.6 ± 0.09%) and mangrove forests (0.9 ± 0.3%) had higher organic carbon in the surface (top 5 cm) sediment than un-vegetated mudflats (0.4 ± 0.04%). Unexpectedly, however, mangrove forests in this region retained organic carbon, rather than outwell it, under normal tidal conditions. No relationship was found between organic carbon and substrate grain size. The most interesting finding of our study was that climax and pioneer seagrass species retained more carbon than mixed-species meadows, suggesting that plant morphology and meadow characteristics can be important factors in organic carbon accumulation. Insights such as these are important in developing carbon management strategies involving coastal ecosystems such as offsetting of carbon emissions. The ability of tropical coastal vegetation to sequester carbon is an important aspect for valuing the ecosystems. Our results provide some initial insight into the factors affecting carbon sequestration in these ecosystems, but also highlight the need for further research on a global scale.

  3. Stress-triggered atavistic reprogramming (STAR) addiction: driving force behind head and neck cancer?

    Masuda, Muneyuki; Wakasaki, Takahiro; Toh, Satoshi


    Recent results of the Cancer Genome Atlas on head and neck squamous cell carcinoma (HNSCC) revealed that HNSCC lacked predominant gain-of-function mutations in oncogenes, whereas an essential role for epigenetics in oncogenesis has become apparent. In parallel, it has gained general acceptance that cancer is considered as complex adaptive system, which evolves responding environmental selective pressures. This somatic evolution appears to proceed concurrently with the acquisition of an atavistic pluripotent state (i.e., “stemness”), which is inducible by intrinsic epigenetic reprogramming program as demonstrated by induced pluripotent stem (iPS) cells. This Nobel prize-winning discovery has markedly accelerated and expanded cancer stem cell research from the point of epigenetic reprogramming. Taken together, we hypothesize that stress-triggered atavistic reprogramming (STAR) may be the major driving force of HNSCC evolution. In this perspective, we discuss the possible mechanisms of STAR in HNSCC, focusing on recent topics of epigenetic reprogramming in developmental and cancer cell biology. PMID:27429838

  4. Invasion of Nostocales (cyanobacteria) to Subtropical and Temperate Freshwater Lakes - Physiological, Regional, and Global Driving Forces.

    Sukenik, Assaf; Hadas, Ora; Kaplan, Aaron; Quesada, Antonio


    Similar to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria) to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of the native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases, global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases, regional changes in nutrient loads and in biotic conditions were attributed to the invasion events.

  5. Spatial-Temporal Pattern and Driving Forces of Land Use Changes in Xiamen

    QUAN Bin; CHEN Jian-Fei; QIU Hong-Lie; M.J.M.R(O)MKENS; YANG Xiao-Qi; JIANG Shi-Feng; LI Bi-Cheng


    Using Landsat TM data of 1988, 1998 and 2001, the dynamic process of the spatial-temporal characteristics of land use changes during 13 years from 1988 to 2001 in the special economic zone of Xiamen, China was analyzed to improve understanding and to find the driving forces of land use change so that sustainable land utilization could be practiced.During the 13 years cropland decreased remarkably by nearly 11304.95 ha. The areas of rural-urban construction and water body increased by 10152.24 ha and 848.94 ha, respectively. From 1988 to 2001, 52.5% of the lost cropland was converted into rural-urban industrial land. Rapid urbanization contributed to a great change in the rate of cropland land use during these years. Land-reclamation also contributed to a decrease in water body area as well as marine ecological and environmental destruction. In the study area 1) urbanization and industrialization, 2) infrastructure and agricultural intensification, 3) increased affluence of the farming community, and 4) policy factors have driven the land use changes.Possible sustainable land use measures included construction of a land management system, land planning, development of potential land resources, new technology applications, and marine ecological and environmental protection.

  6. Driving force for indentation cracking in glass: composition, pressure and temperature dependence.

    Rouxel, Tanguy


    The occurrence of damage at the surface of glass parts caused by sharp contact loading is a major issue for glass makers, suppliers and end-users. Yet, it is still a poorly understood problem from the viewpoints both of glass science and solid mechanics. Different microcracking patterns are observed at indentation sites depending on the glass composition and indentation cracks may form during both the loading and the unloading stages. Besides, we do not know much about the fracture toughness of glass and its composition dependence, so that setting a criterion for crack initiation and predicting the extent of the damage yet remain out of reach. In this study, by comparison of the behaviour of glasses from very different chemical systems and by identifying experimentally the individual contributions of the different rheological processes leading to the formation of the imprint--namely elasticity, densification and shear flow--we obtain a fairly straightforward prediction of the type and extent of the microcracks which will most likely form, depending on the physical properties of the glass. Finally, some guidelines to reduce the driving force for microcracking are proposed in the light of the effects of composition, temperature and pressure, and the areas for further research are briefly discussed.

  7. Rocky Land Desertification and its Driving Forces in the Karst Areas of Rural Guangxi, Southwest China


    With a subtropical climate, Guangxi Zhuaug Autonomous Region has a typical karst landscape. Rocky desertification has become a serious environmental issue due to its high vulnerability caused by the joint effect of natural settings and human activities, because of which its eco- environment has been deteriorated in recent years, and farmland has been disappearing sharply at the same time. This, in turn, has exacerbated the poverty level in the rural areas of the region. In this study, we monitored the spatial distribution of rocky land desertification and its temporal evolution using Landsat TM/ETM images of 1985, 1995, 2000 and 2005. We also analyzed the driving forces of the desertification and its expansion. Through constructing regression models by using all the relevant variables and considering the lagged effects as well as fixed effects, we quantified the exact role of different factors causing rocky land desertification in the study area with some new findings. The newfindings in this study are greatly helpful for preserving, restoring and reconstructing the degraded mountain environment in Guangxi and other karst areas in Southwest China, and also for alleviating poverty in the rural areas in the future.

  8. Yield Improvement and Advanced Defect Control——Driving Forces for Modeling of Bulk Crystal Growth


    Yield improvement and advanced defect control can be identified as the driving forces for modeling of industrial bulk crystal growth. Yield improvement is mainly achieved by upscaling of the whole crystal growth apparatus and increased processing windows with more tolerances for parameter variations. Advanced defect control means on one hand a reduction of the number of deficient crystal defects and on the other hand the formation of beneficial crystal defects with a uniform distribution and well defined concentrations in the whole crystal. This "defect engineering" relates to the whole crystal growth process as well as the following cooling and optional annealing processes, respectively. These topics were illustrated in the paper by examples of modeling and experimental results of bulk growth of silicon (Si), gallium arsenide (GaAs), indium phosphide (InP) and calcium fluoride (CaF2). These examples also involve the state of the art of modeling of the most important melt growth techniques, crystal pulling (Czochralski methods) and vertical gradient freeze (Bridgman-type methods).

  9. Land Use Change and Driving Forces in Guangzhou City during 1996- 2012

    Yiying; YAO; Dafang; WU; Yanyan; LIU; Yihua; LIU; Qixian; CHEN; Haolong; CHEN; Jiaxin; WU; Jialiang; ZHONG


    Based on the statistical data of land use change,from the perspective of sustainable use,we use literature inquiry,statistical analysis,GIS spatial analysis and dynamic degree model of land use,to analyze the land use change characteristics,land use amount and spatial distribution characteristics in Guangzhou City during 1996- 2012,and further elaborate the driving forces of land use change to get the basic law of land use change in Guangzhou City. The results show that the construction land was rapidly expanded,causing a significant reduction in arable land( from 129286 ha in 1996 to 84567 ha in 2012); in construction land,the land for residential,industrial and mining use and transportation land dramatically increased,and the single dynamic degree of transportation land was close to 7. 1%. In comparison with other developed cities,it is found that economic factors and policy factors are important factors affecting land use change in Guangzhou City,and the growth rate of economic density of land was high in Tianhe District and Yuexiu District. From the perspective of sustainable use,the future land use in Guangzhou City needs to better coordinate the relationship between various types of land,between socio-economic development and coordinated land use development,between environmental protection and land development and utilization. Through a series of land consolidation activities,it is necessary to strengthen the protection of farmland,improve the intensive and economical use of construction land,improve the ecological environment,and coordinate development of urban and rural areas,to ultimately achieve sustainable land use in Guangzhou City.

  10. Crop modeling: Studying the effect of water stress on the driving forces governing plant water potential

    van Emmerik, T. H. M.; Mirfenderesgi, G.; Bohrer, G.; Steele-Dunne, S. C.; Van De Giesen, N.


    Water stress is one of the most important environmental factors that influence plant water dynamics. To prevent excessive water loss and physiological damage, plants can regulate transpiration by adjusting the stomatal aperture. This enhances survival, but also reduced photosynthesis and productivity. During periods of low water availability, stomatal regulation is a trade-off between optimization of either survival or production. Water stress defence mechanisms lead to significant changes in plant dynamics, e.g. leaf and stem water content. Recent research has shown that water content in a corn canopy can change up to 30% diurnally as a result of water stress, which has a considerable influence on radar backscatter from a corn canopy [1]. This highlighted the potential of water stress detection using radar. To fully explore the potential of water stress monitoring using radar, we need to understand the driving forces governing plant water potential. For this study, the recently developed the Finite-Element Tree-Crown Hydrodynamic model version 2 (FETCH2) model is applied to a corn canopy. FETCH2 is developed to resolve the hydrodynamic processes within a plant using the porous media analogy, allowing investigation of the influence of environmental stress factors on plant dynamics such as transpiration, photosynthesis, stomatal conductance, and leaf and stem water content. The model is parameterized and evaluated using a detailed dataset obtained during a three-month field experiment in Flevoland, the Netherlands, on a corn canopy. [1] van Emmerik, T., S. Steele-Dunne, J. Judge and N. van de Giesen: "Impact of Diurnal Variation in Vegetation Water Content on Radar Backscatter of Maize During Water Stress", Geosciences and Remote Sensing, IEEE Transactions on, vol. 52, issue 7, doi: 10.1109/TGRS.2014.2386142, 2015.

  11. Changes in Growing Season Vegetation and Their Associated Driving Forces in China during 2001–2012

    Xianfeng Liu


    Full Text Available In recent decades, the monitoring of vegetation dynamics has become crucial because of its important role in terrestrial ecosystems. In this study, a satellite-derived normalized difference vegetation index (NDVI was combined with climate factors to explore the spatiotemporal patterns of vegetation change during the growing season, as well as their driving forces in China from 2001 to 2012. Our results showed that the growing season NDVI increased continuously during 2001–2012, with a linear trend of 1.4%/10 years (p < 0.01. The NDVI in north China mainly exhibited an increasing spatial trend, but this trend was generally decreasing in south China. The vegetation dynamics were mainly at a moderate intensity level in both the increasing and decreasing areas. The significantly increasing trend in the NDVI for arid and semi-arid areas of northwest China was attributed mainly to an increasing trend in the NDVI during the spring, whereas that for the north and northeast of China was due to an increasing trend in the NDVI during the summer and autumn. Different vegetation types exhibited great variation in their trends, where the grass-forb community had the highest linear trend of 2%/10 years (p < 0.05, followed by meadow, and needle-leaf forest with the lowest increasing trend, i.e., a linear trend of 0.3%/10 years. Our results also suggested that the cumulative precipitation during the growing season had a dominant effect on the vegetation dynamics compared with temperature for all six vegetation types. In addition, the response of different vegetation types to climate variability exhibited considerable differences. In terms of anthropological activity, our statistical analyses showed that there was a strong correlation between the cumulative afforestation area and NDVI during the study period, especially in a pilot region for ecological restoration, thereby suggesting the important role of ecological restoration programs in ecological recovery

  12. A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

    Arne Hagman

    Full Text Available Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that

  13. Long-term regional precipitation disparity in northwestern China and its driving forces

    H. F. Lee


    Full Text Available Subject to the unique physical setting of northwestern China (NW China, precipitation in the region is characterized by salient regional differences. Yet, the long-term regional precipitation disparity in NW China still remains insufficiently-explored. In the present study, we base on historical documentation to reconstruct the precipitation indices of two macro regions in NW China between AD580–1979 to address the following issues: (1 determine the multi-decadal to centennial regional precipitation disparity in NW China, a topic which has not been systematically examined in previous paleo-climate/paleo-environment studies; and (2 find the major driving forces behind it. Wavelet analysis, which is ideal for analyzing non-stationary systems, is applied. Our results show that there is significant regional discrepancy of precipitation change in NW China over extended period. Although there is significant association between the regional precipitation disparity in NW China and various modes of atmospheric circulation, the association is characterized by a regime shift during the transition from the Medieval Warm Period to the Little Ice Age. Most importantly, the low-frequency cycle of the El Niño–Southern Oscillation is found to be the most prominent pacemaker of regional precipitation disparity in NW China at the multi-decadal to centennial timescales. Our findings help to demonstrate which atmospheric circulation is primarily responsible for the long-term regional precipitation disparity in NW China, which may have important implications for water resource management in NW China in the near future.

  14. Jordan's First Research Reactor Project: Driving Forces, Present Status and the Way Ahead

    Xoubi, Ned, E-mail: [Jordan Atomic Energy Commission (JAEC), P.O.Box 70, Shafa Badran, 11934 Amman (Jordan)


    In a gigantic step towards establishing Jordan's nuclear power program, Jordan Atomic Energy Commission (JAEC) is building the first nuclear research and test reactor in the Kingdom. The new reactor will serve as the focal point for Jordan Center for Nuclear Research (JCNR), a comprehensive state of the art nuclear center not only for Jordan but for the whole region, the center will include in addition to the reactor a radioisotopes production plant, a nuclear fuel fabrication plant, a cold neutron source (CNS), a radioactive waste treatment facility, and education and training center. The JRTR reactor is the only research reactor new build worldwide in 2010, it is a 5 MW light water open pool multipurpose reactor, The reactor core is composed of 18 fuel assemblies, MTR plate type, with 19.75% enriched uranium silicide (U{sub 3}Si{sub 2}) in an aluminum matrix. It is reflected on all sides by beryllium and graphite blocks. Reactor power is upgradable to 10 MW with a maximum thermal flux of 1.45x10{sup 14} cm{sup -2}s{sup -1}. The reactor reactivity is controlled by four Hafnium Control Absorber Rods (CAR). Jordan Center for Nuclear Research is located in Ramtha city, it is owned by Jordan Atomic Energy Commission (JAEC), and is contracted to Korea Atomic Energy Research Institute (KAERI) and Daewoo E and C. The JCNR project is a 56 months EPC fixed price contract for the design engineering, construction, and commissioning the JCNR reactor, and other nuclear facilities. The project presents many challenges for both the owner and the contractor, being the first nuclear reactor for Jordan, and the first nuclear export for Korea. The driving forces, present status and the way ahead will be presented in this paper. (author)

  15. Detailed Per-residue Energetic Analysis Explains the Driving Force for Microtubule Disassembly.

    Ahmed T Ayoub


    Full Text Available Microtubules are long filamentous hollow cylinders whose surfaces form lattice structures of αβ-tubulin heterodimers. They perform multiple physiological roles in eukaryotic cells and are targets for therapeutic interventions. In our study, we carried out all-atom molecular dynamics simulations for arbitrarily long microtubules that have either GDP or GTP molecules in the E-site of β-tubulin. A detailed energy balance of the MM/GBSA inter-dimer interaction energy per residue contributing to the overall lateral and longitudinal structural stability was performed. The obtained results identified the key residues and tubulin domains according to their energetic contributions. They also identified the molecular forces that drive microtubule disassembly. At the tip of the plus end of the microtubule, the uneven distribution of longitudinal interaction energies within a protofilament generates a torque that bends tubulin outwardly with respect to the cylinder's axis causing disassembly. In the presence of GTP, this torque is opposed by lateral interactions that prevent outward curling, thus stabilizing the whole microtubule. Once GTP hydrolysis reaches the tip of the microtubule (lateral cap, lateral interactions become much weaker, allowing tubulin dimers to bend outwards, causing disassembly. The role of magnesium in the process of outward curling has also been demonstrated. This study also showed that the microtubule seam is the most energetically labile inter-dimer interface and could serve as a trigger point for disassembly. Based on a detailed balance of the energetic contributions per amino acid residue in the microtubule, numerous other analyses could be performed to give additional insights into the properties of microtubule dynamic instability.

  16. Effects of Micropump Driving Parameters on Traveling Wave Driving Force%行波微泵驱动参数对驱动效果的影响

    张冲; 魏守水; 魏长智


    提出一种新型的无阀机械微泵,它依靠微泵管道顶部铺设的压电薄膜阵列产生的超声行波来驱动微管道中的流体。根据超声行波驱动微流体的原理对微泵进行ANSYS有限元建模和CFX流固耦合计算,得到了选定模态下内边长为200μm的方形微泵管道中流体的动力黏度与微泵驱动能力的关系,以及驱动电压幅值和频率对管口流速的影响曲线。结果表明:驱动电压的幅值大小与管口流速成正比,且当驱动频率等于共振频率时驱动效果最明显;当流体动力黏度小于0.001Pa.s时微流体流速随黏度增大而线性增大,之后则缓慢减小。此外,通过CFX后处理得到了微管道中的截面流速矢量图,由矢量图可以看出,在行波驱动作用显著的部分流速分布呈现自微管顶部向下逐渐减慢的特点,而在行波驱动作用极微弱的部分则流速分布近似呈抛物线形状。%A novel type of valveless mechanical micro--pump was proposed herein. It transported the liquid depending on the driving force of traveling wave which was produced by piezoelectric films fabricated on the top surface of the channel. Using finite element software, according to the principle of ultrasonic traveling wave driving,a model was structured and solved. The relationships among the ve- locity of microfluidic and driving factors such as the dynamic viscosity of liquid, the driving voltage amplitude and frequency were obtained for the first time under condition of the selected modal of square micro--pipe with a caliber of 200μm. The results show that the voltage amplitude is propor- tional to the flow velocity and the best driving efficiency is obtained on the resonance frequency;When the dynamic viscosity is below 0. 001Pa · s, the flow velocity will increase along with the rising viscos- ity while decrease above that value. In addition, the section velocity vector diagrams have been ob- tained, which illustrate that the flow

  17. Dynamics of completely unfolded and native proteins through solid-state nanopores as a function of electric driving force.

    Oukhaled, Abdelghani; Cressiot, Benjamin; Bacri, Laurent; Pastoriza-Gallego, Manuela; Betton, Jean-Michel; Bourhis, Eric; Jede, Ralf; Gierak, Jacques; Auvray, Loïc; Pelta, Juan


    We report experimentally the dynamic properties of the entry and transport of unfolded and native proteins through a solid-state nanopore as a function of applied voltage, and we discuss the experimental data obtained as compared to theory. We show an exponential increase in the event frequency of current blockades and an exponential decrease in transport times as a function of the electric driving force. The normalized current blockage ratio remains constant or decreases for folded or unfolded proteins, respectively, as a function of the transmembrane potential. The unfolded protein is stretched under the electric driving force. The dwell time of native compact proteins in the pore is almost 1 order of magnitude longer than that of unfolded proteins, and the event frequency for both protein conformations is low. We discuss the possible phenomena hindering the transport of proteins through the pores, which could explain these anomalous dynamics, in particular, electro-osmotic counterflow and protein adsorption on the nanopore wall.

  18. Sector trends and driving forces of global energy use and greenhouse gas emissions: focus in industry and buildings

    Price, Lynn; Worrell, Ernst; Khrushch, Marta


    Disaggregation of sectoral energy use and greenhouse gas emissions trends reveals striking differences between sectors and regions of the world. Understanding key driving forces in the energy end-use sectors provides insights for development of projections of future greenhouse gas emissions. This report examines global and regional historical trends in energy use and carbon emissions in the industrial, buildings, transport, and agriculture sectors, with a more detailed focus on industry and buildings. Activity and economic drivers as well as trends in energy and carbon intensity are evaluated. The authors show that macro-economic indicators, such as GDP, are insufficient for comprehending trends and driving forces at the sectoral level. These indicators need to be supplemented with sector-specific information for a more complete understanding of future energy use and greenhouse gas emissions.

  19. Examining Land Use and Land Cover Spatiotemporal Change and Driving Forces in Beijing from 1978 to 2010

    Yichen Tian


    Full Text Available Land use and land cover (LULC datasets for Beijing in 1978, 1987, 1992, 2000 and 2010 were developed from Landsat images using the object-oriented classification approach. The relationships between social-economic, demographic and political factors and time-series LULC data were examined for the periods between 1978 and 2010. The results showed the effectiveness of using the object-oriented decision tree classification method for LULC classification with time series of Landsat images. Combined with anthropogenic driving forces, our research can effectively explain the detailed LULC change trajectories corresponding to different stages and give new insights for Beijing LULC change patterns. The results show a significant increase in forest and built-up areas, but a decrease in arable lands, due to urbanization and reforestation. Large ecological projects result in an increase of forest areas and population, and economic conditions result in urban expansion. The anthropogenic driving forces analysis results further prove that both population increase and economic development played important roles in the expansion of built-up areas. Both the qualitative and quantitative anthropogenic driving forces analysis methods were helpful for better understanding the mechanisms of LULC change.

  20. Cultivated Land Changes and Their Driving Forces-A Satellite Remote Sensing Analysis in the Yellow River Delta, China



    Taking Kenli County in the Yellow River Delta, China, as the study area and using digital satellite remote sensing techniques, cultivated land use changes and their corresponding driving forces were explored in this study. An interactive interpretation and a manual modification procedure were carried out to acquire cultivated land information. An overlay method based on classification results and a visual change detection method which was supported by land use maps were employed to detect the cultivated land changes. Based on the changes that were revealed and a spatial analysis between cultivated land use and related natural and socio-economic factors, the driving forces for cultivated land use changes in the study area were determined.The results showed a decrease in cultivated land in Kenli County of 5321.8 ha from 1987 to 1998, i.e.,an average annual decrement of 483.8 ha, which occurred mainly in the central paddy field region and the northeast dry land region. Adverse human activities, soil salinization and water deficiencies were the driving forces that caused these cultivated land use changes.

  1. Critical driving force for martensitic transformation fcc (γ)→hcp(ε) in Fe-Mn-Si shape memory alloys

    金学军; 徐祖耀; 李麟


    By the application of Chou’s new geometry model and the available data from binary Fe-Mn, Fe-Si and Mn-Si systems, as well as SGTE DATA for lattice stability parameters of three elements from Dinsdale, the Gibbs free energy as a function of temperature of the fcc(γ) and hep(ε) phases in the Fe-Mn-Si system is reevaluated. The relationship between the Neel temperature of the γ phase and concentration of constituents in mole fraction, is fitted and verified by the experimental results. The critical driving force for the martensitic transformation fcc (γ)→ hep (ε), △ GCγ→ε, defined as the free energy difference between γ and ε phases at Ms of various alloys can also be obtained with a known Ms. It is found that the driving force varies with the composition of alloys, e. g. △ GCγ→ε = - 100.99 J/mol in Fe-27.0Mn-6.0Si and △ GCγ→ε = - 122.11 J/mol in Fe-26.9Mn-3.37Si. The compositional dependence of critical driving force accorded with the expression formulated by Hsu of the

  2. Quantifying the Driving Forces of Informal Urbanization in the Western Part of the Greater Cairo Metropolitan Region

    Taher Osman


    Full Text Available This paper discusses the driving forces (DFs of informal urbanization (IU in the greater Cairo metropolitan region (GCMR using the Analytic Hierarchy Process (AHP. The IU patterns in the GCMR have been extremely influenced by seven DFs: geographical characteristics, availability of life facilities, economic incentives, land demand and supply, population increase, administrative function, and development plans. This research found that these forces vary significantly in how they influence urban growth in the three study sectors, namely, the middle, north, and south areas in the western part of the GCMR. The forces with the highest influence were economic incentives in the middle sector, population increase in the north sector, and the administrative function in the south sector. Due to the lower availability of buildable land in the middle sector, the land demand and supply force had a lesser influence in this sector compared to in the north and south sectors. The development plans force had medium influence in all sectors. The geographical characteristics force had little influence in both the middle and the north sectors, but higher influence than economic incentives, availability of life facilities, and development plans in the south sector. Because of the spatial variances in life facilities organizations in the GCMR, the life facilities availability force had little effect on IU in the south sector.

  3. Study on the Characteristics and Driving Forces of Changes of the Urban Land-Use Structure in Wuhan in 1990s

    LiuYaobin; 5ongXuefeng


    On the basis of the information entropy and equilibrium degree of urban land-use spatial structure, the paper analyzes the characteristics and rules of urban land-use spatial structure changes in Wuhan in 1990s, in which the types of land-use are shrinking and urban land-use changes are disequilibria. With PCA and GRA employed, the driving forces have also been analyzed. The driving force of city welfare and social structure, the towing force of city industrial structure transition, and the pressing force of city construction and reconstruction are main momentum factors. Moreover, the latter forces are more significant.

  4. Driving forces of main landscape change processes from past 200 years in Central Europe - differences between old democratic and post-socialist countries

    Skokanová Hana


    Full Text Available The article compares and points out differences in driving forces of four main landscape change processes that shaped post-socialist countries and old democratic countries of Central Europe during the last two centuries. Studying landscape change processes and corresponding driving forces helps in understanding patterns of present landscape and can help among others in better prediction of future landscape change trends. Here, the presented results are based on review of scientific articles published in peer-reviewed journals between 2000 and 2014. Driving forces affecting these processes were grouped into four categories. Economic forces drove mainly agricultural intensification; agricultural land abandonment and urbanisation and were pronounced especially in the second half of the 20th century and at the beginning of the 21st century. Technological driving forces affected agricultural intensification especially in the 19th century and the second half of the 20th century while cultural driving forces had the biggest impact on urbanisation at the beginning of the 21st century. Political driving forces affected agricultural intensification, urbanisation as well as agricultural land abandonment and were pronounced mainly during the second half of the 20th century in the post-socialist countries. Political forces in the form of subsidies drove agricultural extensification at the beginning of the 21st century. The drivers for the agricultural intensification as well as urbanisation seem to be similar for both old democratic and post-socialist countries. In contrast, agricultural land abandonment in the old democratic countries was driven by technological, cultural and economic driving forces while in the post-socialist countries the political driving forces were mainly responsible. Changes in systems for subsidies and changes in the agricultural commodity markets are also responsible for different frequencies and rates of extensification of

  5. Understanding the driving forces behind the losses of soil carbon across England and Wales

    Bellamy, Patricia


    More than twice as much carbon is held in soils as in vegetation or the atmosphere, and changes in soil carbon content can have a large effect on the global carbon budget. The possibility that climate change is being reinforced by increased carbon dioxide emissions from soils owing to rising temperature is the subject of a continuing debate. But evidence for the suggested feedback mechanism has to date come solely from small-scale laboratory and field experiments and modelling studies. Here we use data from the National Soil Inventory of England and Wales obtained between 1978 and 2003 to show that carbon was lost from soils across England and Wales over the survey period at a mean rate of 0.6% yr-1 (relative to the existing soil carbon content). We find that the relative rate of carbon loss increased with soil carbon content and was more than 2% yr-1 in soils with carbon contents greater than 100 g kg-1. The relationship between rate of carbon loss and carbon content is irrespective of land use, suggesting a link to climate change. Our findings indicate that losses of soil carbon in England and Wales—and by inference in other temperate regions—are likely to have been offsetting absorption of carbon by terrestrial sinks. To investigate the possible driving forces of the measured losses of soil carbon we applied a simple model of soil carbon turnover to evaluate alternative explanations for the observed trends. We find that neither changes in decomposition resulting from the effects of climate change on soil temperature and moisture, nor changes in carbon input from vegetation, could account on their own for the overall trends. Of other explanations, results indicate that past changes in land use and management were probably dominant. The climate change signal, such as it is, is masked by these other changes. A more sophisticated model of carbon change (DAYCENT) has now been applied across the whole range of soils in England and Wales. This model has been

  6. Self-Biased-SMA Drive PU Microgripper with Force Sensing in Visual Servo

    Ren-Jung Chang


    Full Text Available An innovative design of a polyurethane microgripper system with force sensor is developed for the measurement of gripping force in vision-based control. A microgripper mechanism integrated with a force sensing arm is fabricated by an excimer laser. The microgripper is actuated by a self-biased-SMA (Shape Memory Alloy actuator. A computer-vision method through the ERES (Extended Regional Edge Statistics algorithm is employed to track the motion of gripper. The position information of the gripping point together with the deflection of the force sensing arm is utilized for sensing force. A fuzzy expert with a PI controller in a visual servo is employed to test the performance of sensing the gripping force in grasping of 38μm diameter metal rod. In the performance test, the microgripper system provides a maximum gripping size of 40μm, a maximum force resolution of 1μN and a maximum gripping force of 58μN.

  7. Final Environmental Assessment for New Golf Driving Range at Buckley Air Force Base, Colorado


    include plains cottonwood, Russian olive ( Elaeagnus angustifolia ), Virginia Environmental Assessment New Golf Driving Range Affected Environment...Chenopodium album Lamb’s quarter Chondrosum gracile Blue grama Convolvulus arvensis Bindweed Cynoglossum officinale Hound’s tongue Elaeagnus ... angustifolia Russian olive Lygodesmia juncea Skeleton Plant Opuntia mercerize Prickly pear Pathenocissus quinquifolia Virginia creeper Plantago major

  8. What drives prescribing of asthma medication to preschool wheezing children? A primary care study.

    Montella, Silvia; Baraldi, Eugenio; Bruzzese, Dario; Mirra, Virginia; Di Giorgio, Angela; Santamaria, Francesca


    There is limited information on which data primary care pediatricians (PCPs) use to decide whether to prescribe or not asthma maintenance treatment, and what drives prescribing a specific therapy. The study aim was to investigate how prescribing anti-asthma maintenance treatment to preschool wheezing children is influenced by patient, family, environmental, and PCP characteristics. We conducted a cross-sectional study at 32 PCPs sites in Campania, Italy. Medical, family, and environmental information of 376 preschool wheezy children, and characteristics of the enrolled PCPs were collected. Main outcome measures of multilevel multivariate logistic regression analyses were the prescribing of maintenance treatment, and the prescription of a combined therapy as opposed to monotherapy. Variables significantly associated with long-term inhaled corticosteroids (ICS) and/or leukotriene modifiers prescription included frequent wheezing (OR = 7.19), emergency department (ED) visits (OR = 2.21), personal allergic diseases (OR = 8.49), day-care/kindergarten attendance (OR = 2.67), a high PCP prescribing volume (OR = 2.74), and a low proportion of 0- to 5-year-old patients with wheezing diagnosis (OR = 1.16). Leukotriene modifiers plus ICS were much more likely prescribed than ICS or leukotriene modifiers alone to older children (OR = 1.06) and to patients experiencing frequent wheezing (OR = 3.00), ED visits (OR = 3.12), or tobacco smoke exposure during the first 2 years of life (OR = 2.04). Finally, PCP's characteristics significantly associated with ICS plus leukotriene modifiers prescription were group practice (OR = 4.16) and a high prescribing volume (OR = 1.45). Our findings suggest that child characteristics alone are not sufficient to explain how PCPs decide to prescribe maintenance treatment and which therapy to assign, but variables associated to PCPs are crucial as well.

  9. The unsilent majority-TRPV1 drives "spontaneous" transmission of unmyelinated primary afferents within cardiorespiratory NTS.

    Andresen, Michael C; Hofmann, Mackenzie E; Fawley, Jessica A


    Cranial primary afferent sensory neurons figure importantly in homeostatic control of visceral organ systems. Of the two broad classes of visceral afferents, the role of unmyelinated or C-type class remains poorly understood. This review contrasts key aspects of peripheral discharge properties of C-fiber afferents and their glutamate transmission mechanisms within the solitary tract nucleus (NTS). During normal prevailing conditions, most information arrives at the NTS through myelinated A-type nerves. However, most of visceral afferent axons (75-90%) in NTS are unmyelinated, C-type axons. Centrally, C-type solitary tract (ST) afferent terminals have presynaptic transient receptor potential vanilloid type 1 (TRPV1) receptors. Capsaicin activation of TRPV1 blocks phasic or synchronous release of glutamate but facilitates release of glutamate from a separate pool of vesicles. This TRPV1-operated pool of vesicles is active at normal temperatures and is responsible for actively driving a 10-fold higher release of glutamate at TRPV1 compared with TRPV1- terminals even in the absence of afferent action potentials. This novel TRPV1 mechanism is responsible for an additional asynchronous release of glutamate that is not present in myelinated terminals. The NTS is rich with presynaptic G protein-coupled receptors, and the implications of TRPV1-operated glutamate offer unique targets for signaling in C-type sensory afferent terminals from neuropeptides, inflammatory mediators, lipid metabolites, cytokines, and cannabinoids. From a homeostatic view, this combination could have broad implications for integration in chronic pathological disturbances in which the numeric dominance of C-type endings and TRPV1 would broadly disturb multisystem control mechanisms.

  10. Driving forces analysis of reservoir wetland evolution in Beijing during 1984-2010

    GONG Zhaoning; LI Hong; ZHAO Wenji; GONG Huili


    The reservoir wetland,which is the largest artificial wetland in Beijing,constitutes one of the important urban ecological infrastructures.Considering two elements of natural environment and socio-economy,this paper established the driving factor indexing system of Beijing reservoir wetland evolution.Natural environment driving factors include precipitation,temperature,entry water and groundwater depth; social economic driving factors include resident population,urbanization rate and per capita GDP.Using multi-temporal Landsat TM images from 1984 to 2010 in Beijing,the spatial extent and the distribution of Beijing reservoir wetlands were extracted,and the change of the wetland area about the three decade years were analyzed.Logistic regression model was used to explore for each of the three periods:from 1984 to 1998,from 1998 to 2004 and from 2004 to 2010.The results showed that the leading driving factors and their influences on reservoir wetland evolution were different for each period.During 1984-1998,two natural environment indices:average annual precipitation and entry water index were the major factors driving the increase in wetland area with the contribution rate of Logistic regression being 5.78 and 3.50,respectively,and caused the wetland growth from total area of 104.93 km2 to 219.96 km2.From 1998 to 2004,as the impact of human activities intensified the main driving factors were the number of residents,groundwater depth and urbanization rate with the contribution rate of Logistic regression 9.41,9.18,and 7.77,respectively,and caused the wetland shrinkage rapidly from the total area of 219.96 km2 to 95.71 km2.During 2004-2010,reservoir wetland evolution was impacted by both natural and socio-economic factors,and the dominant driving factors were urbanization rate and precipitation with the contribution rate of 6.62 and 4.22,respectively,and caused the wetland total area growth slightly to 109.73 km2.

  11. Spatial driving forces of dominant land use/land cover transformations in the Dongjiang River watershed, Southern China.

    Gao, Changjun; Zhou, Ping; Jia, Peng; Liu, Zhiyong; Wei, Long; Tian, Huiling


    Information about changes in, and causes of, land use/land cover (LULC) is crucial for land use resource planning. We investigated the processes involved in LULC change (LUCC) in the Dongjiang Watershed, in Southern China, over a 15-year period to gain a better understanding of the causes of the main types of LUCC. Using a depth transition matrix and redundancy analysis (RDA), the major types and causes of LUCC for each LULC type over the past 15 years were identified. LUCC exhibited obvious net change, relatively low persistence, and high swap change. The swap changes in most LULC types were considered as a strong signal of LULC transformations. The driving forces behind swap changes were quantified and identified through RDA. The results showed that all driving forces played important roles in explaining swap changes of LULC, although the relative effects of these drivers varied widely with both LULC type and time period. Swap changes of the LULC types were generally classified into two categories. Some, e.g., built-up land and wetland, were affected mostly by landform and/or distance factors, while others, e.g., grassland and woodland, were modulated mostly by climate and/or socioeconomic factors. Selected spatial driving forces and local land use policies played important roles in explaining the dominant LUCC types, but on different timescales. These findings may improve understanding of the detailed processes involved in LUCC, landscape transformation, and the causes of LUCC in other areas with extensive LUCC and could help managers plan, design, and implement land resource management.

  12. Calculation of the self-formation driving force for composite microstructure in liquid immiscible alloy system

    LIU Xingjun; WANG Cuiping; Ikuo OHNUMA; Ryosuke KAINUMA; Kiyohito ISHIDA; CHEN Xiaohu


    Using Becker's method, we calculate the interfacial energy between two liquid phases in an immiscible system. Based on the Gibbs-Thomson equation, the force acting on the droplet towards the thermal center can be obtained by integrating the interfacial energy between the droplet and matrix liquid phase, which is related to both the radius of a droplet and the temperature gradient. In addition, the forces of gravitation and buoyancy also act on the droplet. The calculated results indicate that the resultant for these forces together mainly decides the microstructure morphology of the solidified alloy. The calculated results are in good agreement with the corresponding experimental results.

  13. The Economic Rationality and Institutional Driving Force of Edible Agro-products Enterprises Adopting ISO9000 Standards

    ZHAO Zhi-jing; WU Xiu-min; CHEN Hong-yue


    This paper analyzed the economic rationality and institutional driving force of edible agro-products enterprises adopting ISO9000 standards,and built the theoretical analysis framework of enterprises adopting ISO9000 standards.The results indicated that the enterprises adopted ISO9000 standards form a variety of promoting product quality and safety business strategy options based on the considerations that getting economic efficiency and the access to resources.Based on the results,some recommendations were given for stimulating enterprises to adopt ISO9000 standards.

  14. Electrochemical reduction of carbon fluorine bond in 4-fluorobenzonitrile Mechanistic analysis employing Marcus Hush quadratic activation-driving force relation

    Muthukrishnan, A.; Sangaranarayanan, M. V.


    The reduction of carbon-fluorine bond in 4-fluorobenzonitrile in acetonitrile as the solvent, is analyzed using convolution potential sweep voltammetry and the dependence of the transfer coefficient on potential is investigated within the framework of Marcus-Hush quadratic activation-driving force theory. The validity of stepwise mechanism is inferred from solvent reorganization energy estimates as well as bond length calculations using B3LYP/6-31g(d) method. A novel method of estimating the standard reduction potential of the 4-fluorobenzonitrile in acetonitrile is proposed.

  15. Motion of essentially admissible V-shaped polygonal curves govorned by generalized crystalline motion with a driving force

    ISHIWATA, Tetsuya


    In this paper we consider the motion of non-closed planar polygonal curves governed by generalized crystalline curvature flow with a driving force. In the context of ”crystalline motion”, we usually restrict the curves in the special class of polygonal curves, so-called ”admissible class.” We here extend the previous results to wider class which is called ”essentially admissible class.” In such a class, there are no order-preserving structure, thus, controlling the movement of the solution cu...

  16. Effect of Lanthanum on Driving Force for Cu6Sn5 Growth and Improvement of Solder Joint Reliability


    By means of adding low content of rare earth element La into Sn60-Pb40 solder alloy, the growth of Cu6Sn5 intermetallic compound at the interface of solder joint is hindered, and the thermal fatigue life of solder joint is increased by 2 times. The results of thermodynamic calculation based on diffusion kinetics show that, the driving force for Cu6Sn5 growth is lowered by adding small content of La in Sn60-Pb40 solder alloy. Meanwhile, there is an effective local mole fraction range of La, in which, 0.18% is the limited value and 0.08% is the best value.

  17. Protein folding: complex potential for the driving force in a two-dimensional space of collective variables.

    Chekmarev, Sergei F


    Using the Helmholtz decomposition of the vector field of folding fluxes in a two-dimensional space of collective variables, a potential of the driving force for protein folding is introduced. The potential has two components. One component is responsible for the source and sink of the folding flows, which represent respectively, the unfolded states and the native state of the protein, and the other, which accounts for the flow vorticity inherently generated at the periphery of the flow field, is responsible for the canalization of the flow between the source and sink. The theoretical consideration is illustrated by calculations for a model β-hairpin protein.

  18. Multi-scales Analysis of Driving Forces on Land Use/Cover Change in China: Taking Farmland Returning to Forest or Grassland as a Case

    Zhou Hongjian; Huang Shuling; Wang Yuanyuan; Wang Jing'ai; Jia Huicong


    Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecological security level and influences the regional sustainable development. Adjusting unreasonable land use mode and reconstructing natural land cover are important ways to maintain and improve the ecological environment. Also reclaiming farmland as areas for forests and grasslands (FRFG) is another way. Successful implementation of FRFG in China is the result of comprehensive effect of the multi-scales driving forces.This paper analyses the driving forces of FRFG in China on a national (country) -regional (province) - local(county) - household (farmer) level scale, and the results are: driving forces at the national scale include ecological and food security and the western development of China;at the regional scale, ecological and economic benefits become the main factors to influence the dimension of FRFG under the same policy. The driving forces can be divided into 6 types: industrial structure adjustment,water source protection, flood prevention, the Three-Gorge Project protection, reduction of the amount of sediment flowing into the Yellow River and wind erosion desertification prevention. The driving forces at the local scale can be divided into 12 types with developing leading industries, increasing farmers'income and improving agricultural production conditions as the main types; at the household scale, the national policy meeting farmers' demands and the optimization of individual interests are all driving forces.

  19. Predation risk as a driving force for phenotypic assortment: a cross-population comparison.

    Croft, D P; Darden, S K; Ruxton, G D


    Frequency-dependent predation has been proposed as a general mechanism driving the phenotypic assortment of social groups via the 'oddity effect', which occurs when the presence of odd individuals in a group allows a predator to fixate on a single prey item, increasing the predator's attack-to-kill ratio. However, the generality of the oddity effect has been debated and, previously, there has not been an ecological assessment of the role of predation risk in driving the phenotypic assortment of social groups. Here, we compare the levels of body length assortment of social groups between populations of the Trinidadian guppy (Poecilia reticulata) that experience differences in predation risk. As predicted by the oddity effect hypothesis, we observe phenotypic assortment by body length to be greater under high predation risk. However, we found that a number of low-predation populations were also significantly assorted by body length, suggesting that other mechanisms may have a role to play.

  20. Bilateral deficit in explosive force production is not caused by changes in agonist neural drive.

    Matthew W Buckthorpe

    Full Text Available Bilateral deficit (BLD describes the phenomenon of a reduction in performance during synchronous bilateral (BL movements when compared to the sum of identical unilateral (UL movements. Despite a large body of research investigating BLD of maximal voluntary force (MVF there exist a paucity of research examining the BLD for explosive strength. Therefore, this study investigated the BLD in voluntary and electrically-evoked explosive isometric contractions of the knee extensors and assessed agonist and antagonist neuromuscular activation and measurement artefacts as potential mechanisms. Thirteen healthy untrained males performed a series of maximum and explosive voluntary contractions bilaterally (BL and unilaterally (UL. UL and BL evoked twitch and octet contractions were also elicited. Two separate load cells were used to measure MVF and explosive force at 50, 100 and 150 ms after force onset. Surface EMG amplitude was measured from three superficial agonists and an antagonist. Rate of force development (RFD and EMG were reported over consecutive 50 ms periods (0-50, 50-100 and 100-150 ms. Performance during UL contractions was compared to combined BL performance to measure BLD. Single limb performance during the BL contractions was assessed and potential measurement artefacts, including synchronisation of force onset from the two limbs, controlled for. MVF showed no BLD (P = 0.551, but there was a BLD for explosive force at 100 ms (11.2%, P = 0.007. There was a BLD in RFD 50-100 ms (14.9%, P = 0.004, but not for the other periods. Interestingly, there was a BLD in evoked force measures (6.3-9.0%, P<0.001. There was no difference in agonist or antagonist EMG for any condition (P≥0.233. Measurement artefacts contributed minimally to the observed BLD. The BLD in volitional explosive force found here could not be explained by measurement issues, or agonist and antagonist neuromuscular activation. The BLD in voluntary and evoked explosive force

  1. Increasing climate extremes under global warming - What is the driving force?

    Yoon, Jin-Ho


    More climate extreme events have occurred in recent years, including the continual development of extreme drought in California, the severe cold winters in the eastern U.S. since 2014, 2015 Washington drought, and excessive wildfire events over Alaska in 2015. These have been casually attributed to global warming. However, a need for further understanding of mechanisms responsible for climate extremes is growing. In this presentation, we'll use sets of climate model simulation that designed to identify the role of the oceanic feedback in increasing climate extremes under global warming. One is with a fully coupled climate model forced by 1% ramping CO2, and the other is with an atmosphere only model forced by the same CO2 forcing. By contrasting these two, an importance of the oceanic feedback in increasing climate extremes under global warming can be diagnosed.

  2. Blood pressure is the major driving force for plaque formation in aortic-constricted ApoE-/- mice

    Johansson, Maria E.; Wickman, Anna; Skøtt, Ole


    OBJECTIVE: Using an aortic constriction model in mice, we studied whether the increase in pressure or the activation of the renin-angiotensin system (RAS) and its main receptors is the main driving force for plaque progression. METHODS: Male ApoE mice underwent sham surgery or placement of a supr......OBJECTIVE: Using an aortic constriction model in mice, we studied whether the increase in pressure or the activation of the renin-angiotensin system (RAS) and its main receptors is the main driving force for plaque progression. METHODS: Male ApoE mice underwent sham surgery or placement...... of a suprarenal silver clip around the aorta (AoC). Half the group was treated with the selective AT1 receptor antagonist losartan (30 mg/kg per day) for 4 weeks. RESULTS: Anesthetized mean arterial pressure (MAP) was increased in AoC mice compared to sham (106 +/- 3 versus 90 +/- 1 mmHg, P ....09 versus 0.07 +/- 0.01%, P distribution. Furthermore, we found no support...

  3. [Land use change dynamics and driving forces of the vulnerable ecological region in northwestern Shanxi Province, China].

    Li, Xiu-Fen; Liu, Li-Min; Qi, Xin; Zhang, Jin-Xin; Zhao, Tong-Bin; Wang, Yi; Liu, Xue-Fen; Zhou, Yong-Bin


    By using remote sensing and GIS technology, this paper collected land use information of 1980, 1990, 2000 and 2010 and the relevant statistical data, and analyzed the characteristics of land use change and its driving forces in northwestern Shanxi Province, the typical ecological fragile area. The results showed that there were significant changes in land use patterns in the past 30 years. During 1980-1990, 1990-2000 and 2000-2010 periods, the area of farmland decreased continuously, while the areas of grassland and woodland experienced increase-decrease-increase and decrease-increase-decrease patterns of change, respectively. The areas of industrial and resident lands increased continuously, but the water body and unused land decreased. The farmland was mainly transformed to grassland and woodland, and the areas of industrial and resident lands increased from the farmland. The lost area of water body was transformed to grassland and farmland. The decrease of unused land was due to the implementation of ecological engineering and urban ex-panding. In general, the changes of land use types were significantly higher before 2000 than after 2000. The industrial and resident lands, unused land and grassland changed drastically. The relationships between land use types and driving forces indicated that population pressure and economic development led to the changes of industrial land and farmland; policy of forestry ecological engi- neering drove the changes of woodland and grassland; the drought-characterized climate was the major cause inducing the decrease of water area and hindering the restoration of forest.

  4. The Effects of Dominant Driving Forces on Summer Precipitation during Different Periods in Beijing

    Fuxing Li


    Full Text Available Wavelet analysis methods (CWT, XWT, WTC were employed to evaluate the impact of dominant climatic driving factors on summer precipitation in the Beijing area based on monthly precipitation data of Beijing ranging from 1880 to 2014. The two climatic driving factors, i.e., the East Asian summer monsoon (EASM and the Northern Limit of Western Pacific Subtropical High (NWPSH were considered in particular. The relationships between summer precipitation and EASM/NWPSH were also examined. The results revealed similar periods in low-frequency oscillation (76–95 years and mid-range frequency oscillation (32–60 years for the summer precipitation in the Beijing area and EASM/NWPSH. The summer precipitation correlated positively with the NWPSH and EASM, especially for periods of 43 years and 33 years, respectively. This indicates that summer precipitation during 1880–1960 and during the years after 1960 was significantly affected by NWPSH and EASM, respectively. Based on the periodic change of 33 years for both summer precipitation and EASM, heavy precipitation can be expected to occur again in Beijing at approximately 2026. Understanding the relationships between summer precipitation and climatic factors is of significant importance for precipitation predictions and water resource variations in the Beijing area.

  5. Increases in inspiratory neural drive in response to rapid oscillating airflow braking forces (vibration).

    Sumners, David Paul; Green, David A; Mileva, Katya N; Bowtell, Joanna L


    To investigate whether 10 breaths against a vibration stimulus elicits increments of spontaneous and maximal inspiratory mouth pressure (maxMP) and tidal mean inspiratory flow (iV(T)/T(I)) upon stimulus removal. Twelve healthy subjects (8 female, 4 male; 22-50 years old), recruited from the University student body, completed 3 maximal inspirations before (pre) and after (post) 10 inspirations against resistive loading with a vibration-type stimulus (VIB; youbreathe, Exoscience Ltd., London, UK), pressure-matched resistive loading (RES) or resting breathing (CON; no load). The trials were presented in a random order. maxMP and involuntary tidal breathing were compared pre and post conditioning. Inspiratory neural drive increased only after VIB as evidenced by increased tidal and maxMP and mean inspiratory flow (iV(T)/T(I); p control breathing on maximal maxMP or tidal responses. Ten conditioning breaths of VIB lead to increased maximal inspiratory mouth pressure and spontaneous mouth pressure and mean inspiratory flow possibly through a common mechanism of increased descending respiratory drive.

  6. The Study on the Block Boundary's Driving Forces and Tectonic Stress Field of China Mainland and Its Adjacent Areas Using GPS Data

    Du Zhi-xing; Qu Ji-kun; Han Bao-min; Jin Feng-xiang; Chai Yan-ju


    After reviewing the inversion study on the driving forces of China mainland and its adjacent areas, the inversion computation is made by means of genetic finite element method and covering complex method based on the displacement observations of the Crustal Movement Observation Network of China. The whole procedures of inversion study, including parameter selection, computation conditions, inversion analysis and interpretation, are given out in details. Then some conclusions are drawn:(1)the main driving forces acting on China mainland are still from the collision of Indian plate with Eurasian plate;(2)the driving forces of Pacific plate and Philippine plate are significant to the eastern China;(3)the back basin of Japan sea arc is continuously extending;(4)the forces from north prevent the northern motion of China.

  7. Self-similar expansion of solar coronal mass ejections: Implications for Lorentz self-force driving

    Subramanian, Prasad; Arunbabu, K. P.; Mauriya, Adwiteey [Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India); Vourlidas, Angelos, E-mail: [Space Science Division, Naval Research Laboratory, 4555 Overlook Avenue, SW Washington, DC 20375 (United States)


    We examine the propagation of several coronal mass ejections (CMEs) with well-observed flux rope signatures in the field of view of the SECCHI coronagraphs on board the STEREO satellites using the graduated cylindrical shell fitting method of Thernisien et al. We find that the manner in which they propagate is approximately self-similar; i.e., the ratio (κ) of the flux rope minor radius to its major radius remains approximately constant with time. We use this observation of self-similarity to draw conclusions regarding the local pitch angle (γ) of the flux rope magnetic field and the misalignment angle (χ) between the current density J and the magnetic field B. Our results suggest that the magnetic field and current configurations inside flux ropes deviate substantially from a force-free state in typical coronagraph fields of view, validating the idea of CMEs being driven by Lorentz self-forces.

  8. Both contractile axial and lateral traction force dynamics drive amoeboid cell motility.

    Bastounis, Effie; Meili, Ruedi; Álvarez-González, Begoña; Francois, Joshua; del Álamo, Juan C; Firtel, Richard A; Lasheras, Juan C


    Chemotaxing Dictyostelium discoideum cells adapt their morphology and migration speed in response to intrinsic and extrinsic cues. Using Fourier traction force microscopy, we measured the spatiotemporal evolution of shape and traction stresses and constructed traction tension kymographs to analyze cell motility as a function of the dynamics of the cell's mechanically active traction adhesions. We show that wild-type cells migrate in a step-wise fashion, mainly forming stationary traction adhesions along their anterior-posterior axes and exerting strong contractile axial forces. We demonstrate that lateral forces are also important for motility, especially for migration on highly adhesive substrates. Analysis of two mutant strains lacking distinct actin cross-linkers (mhcA(-) and abp120(-) cells) on normal and highly adhesive substrates supports a key role for lateral contractions in amoeboid cell motility, whereas the differences in their traction adhesion dynamics suggest that these two strains use distinct mechanisms to achieve migration. Finally, we provide evidence that the above patterns of migration may be conserved in mammalian amoeboid cells.

  9. Line tension at lipid phase boundaries as driving force for HIV fusion peptide-mediated fusion

    Yang, Sung-Tae; Kiessling, Volker; Tamm, Lukas K.


    Lipids and proteins are organized in cellular membranes in clusters, often called `lipid rafts'. Although raft-constituent ordered lipid domains are thought to be energetically unfavourable for membrane fusion, rafts have long been implicated in many biological fusion processes. For the case of HIV gp41-mediated membrane fusion, this apparent contradiction can be resolved by recognizing that the interfaces between ordered and disordered lipid domains are the predominant sites of fusion. Here we show that line tension at lipid domain boundaries contributes significant energy to drive gp41-fusion peptide-mediated fusion. This energy, which depends on the hydrophobic mismatch between ordered and disordered lipid domains, may contribute tens of kBT to fusion, that is, it is comparable to the energy required to form a lipid stalk intermediate. Line-active compounds such as vitamin E lower line tension in inhomogeneous membranes, thereby inhibit membrane fusion, and thus may be useful natural viral entry inhibitors.

  10. Chronic Inflammation-Related HPV: A Driving Force Speeds Oropharyngeal Carcinogenesis.

    Liu, Xin; Ma, Xiangrui; Lei, Zhengge; Feng, Hao; Wang, Shasha; Cen, Xiao; Gao, Shiyu; Jiang, Yaping; Jiang, Jian; Chen, Qianming; Tang, Yajie; Tang, Yaling; Liang, Xinhua


    Oropharyngeal squamous cell carcinoma (OPSCC) has been known to be a highly aggressive disease associated with human papilloma virus (HPV) infection. To investigate the relationship between HPV and chronic inflammation in oropharyngeal carcinogenesis, we collected 140 oral mucous fresh specimens including 50 OPSCC patients, 50 cancer in situ, 30 precancerous lesions, and 10 normal oral mucous. Our data demonstrated that there was a significantly higher proportion of severe chronic inflammation in dysplastic epithelia in comparison with that in normal tissues (Pchronic inflammation degrees from mild to severe inflammation (Pinflammation response and immune suppression in HPV-positive OPSCC. These indicated that persistent chronic inflammation-related HPV infection might drive oropharyngeal carcinogenesis and MDSCs might pay an important role during this process. Thus, a combination of HPV infection and inflammation expression might become a helpful biomedical marker to predict oropharyngeal carcinogenesis.

  11. Spatial Patterns and Driving Forces of Greenhouse Land Change in Shouguang City, China

    Bohua Yu


    Full Text Available As an important facet of modern agricultural development, greenhouses satisfy ever-increasing demands for agricultural production and, therefore, constitute a growing proportion of global agriculture. However, just a handful of countries regularly collect statistics on the land cover of greenhouse infrastructure. Even when collected, these data cannot provide the detailed spatial information required for environmental risk assessment. It is, therefore, important to map spatial changes in greenhouse land cover using remote sensing (RS approaches to determine the underlying factors driving these changes. In this paper, we apply a support vector machine (SVM algorithm to identify greenhouse land cover in Shouguang City, China. Enhanced thematic mapper (ETM images were selected as the data source for land use classification in this study as they can be freely acquired and offer the necessary spatial resolution. We then used a binary logistic regression model to quantitatively discern the mechanisms underlying changes in greenhouse land cover. The results of this study show that greenhouse land cover in Shouguang increased by 50.51% between 2000 and 2015, and that 90.39% of this expansion took place between 2010 and 2015. Elevation, slope, precipitation, and the distance to the nearest rural settlements and coastline are all significant factors driving expansion in greenhouse land cover, while distance to the nearest urban areas, rivers, roads, railways, and coastline have contributed to contractions in this land use type. Our research provided a practical approach to allow the detection of changes in greenhouse land cover in the countries with using free or low-cost satellite images.

  12. Driving force for the hydration of the swelling clays: case of montmorillonites saturated with alkaline-earth cations.

    Salles, Fabrice; Douillard, Jean-Marc; Bildstein, Olivier; Gaudin, Cedric; Prelot, Benedicte; Zajac, Jerzy; Van Damme, Henri


    Important structural modifications occur in swelling clays upon water adsorption. The multi-scale evolution of the swelling clay structure is usually evidenced by various experimental techniques. However, the driving force behind such phenomena is still not thoroughly understood. It appears strongly dependent on the nature of the interlayer cation. In the case of montmorillonites saturated with alkaline cations, it was inferred that the compensating cation or the layer surface could control the hydration process and thus the opening of the interlayer space, depending on the nature of the interlayer cation. In the present study, emphasis is put on the impact of divalent alkaline-earth cations compensating the layer charge in montmorillonites. Since no experimental technique offers the possibility of directly determining the hydration contributions related to interlayer cations and layer surfaces, an approach based on the combination of electrostatic calculations and immersion data is developed here, as already validated in the case of montmorillonites saturated by alkaline cations. This methodology allows to estimate the hydration energy for divalent interlayer cations and therefore to shed a new light on the driving force for hydration process occurring in montmorillonites saturated with alkaline-earth cations. Firstly, the surface energy values obtained from the electrostatic calculations based on the Electronegativity Equalization Method vary from 450 mJ m(-2) for Mg-montmorillonite to 1100 mJ m(-2) for Ba-montmorillonite. Secondly, considering both the hydration energy for cations and layer surfaces, the driving force for the hydration of alkaline-earth saturated montmorillonites can be attributed to the interlayer cation in the case of Mg-, Ca-, Sr-montmorillonites and to the interlayer surface in the case of Ba-montmorillonites. These results explain the differences in behaviour upon water adsorption as a function of the nature of the interlayer cation

  13. Scientific Élan Vital: Entropy Deficit or Inhomogeneity as a Unified Concept of Driving Forces of Life in Hierarchical Biosphere Driven by Photosynthesis

    Naoki Sato


    Full Text Available Life is considered something different from non-living things, but no single driving force can account for all the different aspects of life, which consists of different levels of hierarchy, such as metabolism, cell physiology, multi-cellular development and organization, population dynamics, ecosystem, and evolution. Although free energy is evidently the driving force in biochemical reactions, there is no established relationship between metabolic energy and spatiotemporal organization of living organisms, or between metabolic energy and genetic information. Since Schrödinger pointed out the importance of exporting entropy in maintaining life, misunderstandings of entropy notion have been obstacles in constructing a unified view on the driving forces of life. Here I present a simplified conceptual framework for unifying driving forces of life at various different levels of hierarchy. The key concept is “entropy deficit”, or simply, ‘inhomogeneity’, which is defined as the difference of maximal possible entropy and actual entropy. This is equivalent to information content in genetic information and protein structure, and is also defined similarly for non-homogeneous structures in ecosystems and evolution. Entropy deficit or inhomogeneoity is a unified measure of all driving forces of life, which could be considered a scientific equivalent to ‘élan vital’ of Bergson.

  14. Embryo as epiphenomenon: some cultural, social and economic forces driving the stem cell debate.

    Green, R M


    Our human embryonic stem cell debates are not simply about good or bad ethical arguments. The fetus and the embryo have instead become symbols for a larger set of value conflicts occasioned by social and cultural changes. Beneath our stem cell debates lie conflicts between those who would privilege scientific progress and individual choice and others who favour the sanctity of family life and traditional family roles. Also at work, on both the national and international levels, is the use of the embryo by newly emergent social groups to express resentment against cultural elites. The organisational needs of religious groups have also played a role, with the issue of protection of the embryo and fetus serving as a useful means of rallying organisational allegiance in the Roman Catholic and evangelical communities. Because the epiphenomenal moral positions on the status and use of the embryo are driven by the powerful social, cultural or economic forces beneath them, they will most likely change only with shifts in the underlying forces that sustain them.

  15. The Role of CO2 Physiological Forcing in Driving Future Precipitation Variability and Precipitation Extremes

    Skinner, C. B.; Poulsen, C. J.


    Transpired water contributes roughly 25% to total precipitation over the Earth's land surface. In addition to transpiration's impact on climatological mean precipitation, recent work suggests that transpiration reduces daily and intraseasonal precipitation variability in tropical forest regions. Projected increases in the concentration of CO2 are expected to reduce transpiration through changes in plant physiology (termed the CO2 physiological effect). Here, we use an ensemble of climate model experiments to assess the potential contribution of the CO2 physiological effect to future changes in precipitation variability and extreme precipitation events. Within our model simulations, precipitation responses to the physiological effects of increased CO2 concentrations are greatest throughout the tropics. In most tropical forest regions CO2 physiological forcing increases the annual number of dry (less than 0.1 mm/day) and extremely wet (rainfall exceeds 95th percentile) days. Changes in precipitation are primarily driven by an increase in surface temperature and subsequent changes in atmospheric stability and moisture convergence over vegetated tropical land regions. Our results suggest that the plant physiological response to CO2 forcing may serve as an important contributor to future precipitation variability in the tropics, and that future work should aim to reduce uncertainty in the response of plant physiology to changes in climate.

  16. The driving force of prophages and CRISPR-Cas system in the evolution of Cronobacter sakazakii

    Zeng, Haiyan; Zhang, Jumei; Li, Chensi; Xie, Tengfei; Ling, Na; Wu, Qingping; Ye, Yingwang


    Cronobacter sakazakii is an important foodborne pathogens causing rare but life-threatening diseases in neonates and infants. CRISPR-Cas system is a new prokaryotic defense system that provides adaptive immunity against phages, latter play an vital role on the evolution and pathogenicity of host bacteria. In this study, we found that genome sizes of C. sakazakii strains had a significant positive correlation with total genome sizes of prophages. Prophages contributed to 16.57% of the genetic diversity (pan genome) of C. sakazakii, some of which maybe the potential virulence factors. Subtype I-E CRISPR-Cas system and five types of CRISPR arrays were found in the conserved site of C. sakazakii strains. CRISPR1 and CRISPR2 loci with high variable spacers were active and showed potential protection against phage attacks. The number of spacers from two active CRISPR loci in clinical strains was significant less than that of foodborne strains, it maybe a reason why clinical strains were found to have more prophages than foodborne strains. The frequently gain/loss of prophages and spacers in CRISPR loci is likely to drive the quick evolution of C. sakazakii. Our study provides a new insight into the co-evolution of phages and C. sakazakii. PMID:28057934

  17. Farming and forestry land use changes in China and their driving forces from 1900 to 1980

    GE; Quansheng; DAI; Junhu


    A variety of agricultural and forestry land use materials, especially those in the first half of 20th century, were collected. According to land use change in this period, the whole country is demarcated into seven regions, Northeast China, North China, Northwest and Loess Plateau, Southeast and Coastal Region, Southwest China, Qinghai-Tibetan Plateau, Inner Mongolia and Xinjiang, in proper order by using Cluster Analysis. The farming and forestry land use change in these regions were analyzed. The results show that the total cultivated land areas increased in this period, especially in the 1950s and 1960s the cultivated land area increased more significantly, but differed in different regions, and the most rapid increasing rate was 2.63 percent a year. On the other hand, the forestry land area was increasing in most parts of this period, especially after 1949. But in most regions, the decrease of forestry land area at the end of 1970s is also very obvious. It is regarded that the population increase, food production, natural disasters and some related government policies were among the main driving factors for farming and forestry land use change.

  18. Regulatory gene mutation: a driving force behind group a Streptococcus strain- and serotype-specific variation.

    Sarkar, Poulomee; Sumby, Paul


    Data from multiple bacterial pathogens are consistent with regulator-encoding genes having higher mutation frequencies than the genome average. Such mutations drive both strain- and type- (e.g., serotype, haplotype) specific phenotypic heterogeneity, and may challenge public health due to the potential of variants to circumvent established treatment and/or preventative regimes. Here, using the human bacterial pathogen the group A Streptococcus (GAS; S. pyogenes) as a model organism, we review the types and regulatory-, phenotypic-, and disease-specific consequences of naturally occurring regulatory gene mutations. Strain-specific regulator mutations that will be discussed include examples that transform isolates into hyper-invasive forms by enhancing expression of immunomodulatory virulence factors, and examples that promote asymptomatic carriage of the organism. The discussion of serotype-specific regulator mutations focuses on serotype M3 GAS isolates, and how the identified rewiring of regulatory networks in this serotype may be contributing to a decades old epidemiological association of M3 isolates with particularly severe invasive infections. We conclude that mutation plays an outsized role in GAS pathogenesis and has clinical relevance. Given the phenotypic variability associated with regulatory gene mutations, the rapid examination of these genes in infecting isolates may inform with respect to potential patient complications and treatment options.

  19. Tendency to occupy a statistically dominant spatial state of the flow as a driving force for turbulent transition

    Chekmarev, Sergei F


    A simple analytical model for a turbulent flow is proposed, which considers the flow as a collection of localized spatial structures that are composed of elementary "cells" in which the state of the particles (atoms or molecules) is uncertain. The Reynolds number is associated with the ratio between the total phase volume for the system and that for the elementary cell. Calculating the statistical weights of the collections of the localized structures, it is shown that as the Reynolds number increases, the elementary cells group into the localized structures, which successfully explains the onset of turbulence and some other characteristic properties of turbulent flows. It is also shown that the basic assumptions underlying the model are involved in the derivation of the Navier-Stokes equation, which suggests that the driving force for the turbulent transition described with the hydrodynamic equations is essentially the same as in the present model, i.e. the tendency of the system to occupy a statistically do...

  20. Solvent driving force ensures fast formation of a persistent and well-separated radical pair in plant cryptochrome

    Lüdemann, Gesa; Solov'yov, Ilia; Kubar, Tomás


    radical pair has despite various theoretical and experimental efforts not been unambiguously identified yet. We challenge this unambiguity through a unique quantum mechanical molecular dynamics approach where we perform electron transfer dynamics simulations taking into account the motion of the protein......The photoreceptor protein cryptochrome is thought to host, upon light absorption, a radical pair which is sensitive to very weak magnetic fields, endowing migratory birds with a magnetic compass sense. The molecular mechanism which leads to formation of a stabilised, magnetic field sensitive...... upon the electron transfer. This approach allows us to follow the time evolution of the electron transfer in an unbiased fashion and to reveal the molecular driving force which ensures fast electron transfer in cryptochrome guaranteeing formation of a persistent radical pair suitable...

  1. Driving forces behind the increasing cardiovascular treatment intensity.A dynamic epidemiologic model of trends in Danish cardiovascular drug utilization.

    Kildemoes, Helle Wallach; Andersen, Morten

    followed with respect to out-of-hospital redemptions of cardiovascular prescription drugs in the period 1996-2005. The impact of population ageing on cardiovascular treatment intensity was investigated by comparing crude and age/gender standardised intensities. Epidemiologic model: We developed a three...... prevalence. Conclusions: Increasing cardiovascular treatment intensity was driven by increases in age/gender specific drug use - rather than by population ageing. Although the increased prevalence of use in all age groups reflects an increasing incidence, recruitment of long-term users is expected to add......Background: In many Western countries cardiovascular treatment intensity (DDD/1000 inhabitants/day, DDD/TID) has grown substantially during the last decades. Changed drug utilization pattern - rather than population ageing - was hypothesized to be the main driving force behind the growth...

  2. Solvent driving force ensures fast formation of a persistent and well-separated radical pair in plant cryptochrome

    Lüdemann, Gesa; Solov'yov, Ilia; Kubar, Tomás;


    The photoreceptor protein cryptochrome is thought to host, upon light absorption, a radical pair which is sensitive to very weak magnetic fields, endowing migratory birds with a magnetic compass sense. The molecular mechanism which leads to formation of a stabilised, magnetic field sensitive radi...... upon the electron transfer. This approach allows us to follow the time evolution of the electron transfer in an unbiased fashion and to reveal the molecular driving force which ensures fast electron transfer in cryptochrome guaranteeing formation of a persistent radical pair suitable...... for magnetoreception. We argue that this unraveled molecular mechanism is a general principle inherent to all proteins of the cryptochrome/photolyase family and that cryptochromes are, therefore, tailored to potentially function as efficient chemical magnetoreceptors....

  3. Analysis on Temporal and Spatial Changes and Driving Forces of Poverty-Stricken Areas in Hebei Province

    Shi Xiaoli; Yuan Jinguo; Wang Wei


    This paper takes poverty-stricken county as the basic unit, and selects net income per peasant to study the poverty status in Hebei Province during 1986~2000.Temporal and spatial changes of povertystricken areas are analyzed. The result shows that poverty-stricken areas in Hebei Province distributed concentratedly and the areas decreased during 1986~2000, the net income per peasant was on the rise with an increasing speed in off-poverty counties being slightly higher than that in poverty-stricken counties, but the growth rate was extremely unstable,rising slowly in off-poverty counties while dropping in poverty-stricken counties. The main driving forces that influenced temporal and spatial changes were economic development of the whole province,ecological environment quality, infrastructure conditions and radiation of the key city. On this basis, some anti-poverty countermeasures suitable to local conditions are proposed.

  4. On the possibility of the electron polarization to be the driving force for the C60-TMB nanowire growth

    Solov'yov, Ilia; Geng, Junfeng; Solov'yov, Andrey V.;


    The effect of electron polarization has been suggested to explain the exceptionally large length-to width aspect ratio (more than 3000) in recently observed C_60-based nanowires. The theoretical estimates performed in the present Letter show that at room temperature the effect of electron...... polarization is negligibly small and, therefore, cannot become the driving force for nanowire growth along one preferential direction. Experimental measurements are in agreement with the theoretical analysis: the nanowires have been observed to emerge from the polar 1,2,4-trimethylbenzene and non-polar 1......,3,5-trimethylbenzene solution of C_60, while no nanowires from polar toluene, 1,2,3-trimethylbenzene and non-polar benzene solutions could be recorded....

  5. Study on driving forces of wetland change in the Western Liaohe River basin based on random forest model

    Wu, Menghong; Yang, Changbao; Zhang, Yanhong; Lin, Nan


    Based on the platform of RS and GIS, random forest progression model is used for study driving force of wetland change in western Liaohe river basin, five influencing factors which include elevation, slope, temperature, precipitation and population density are chosen to establish random forest progression model about the wetland change and the driving factors. Using the the mean value of the prediction accuracy outside the bag calculated by the model to evaluate the importance of the variables. The result indicates that the coefficient of partial correlation between precipitation and wetland density is the largest among the five influencing factors, followed by temperature, population density, elevation and slope is smallest. The influence of natural factors on the change of wetland density is mainly reflected in precipitation and temperature factors, and the precipitation is obviously higher than that of temperature, under the influence of human factors, the influence of population density factor on wetland density is higher than that of elevation and slope factor. The result shows that in the past 40 years, the human activities in the study area have increased the density of wetland to some extent, but it is not the main factor.

  6. Analysis of spatio-temporal pattern and driving force of land cover change using multi-temporal remote sensing images


    Landuse and land cover change is regarded as a good indicator that represents the impact of human activities on earth’s environment.When the large collection of multi-temporal satellite images has become available,it is possible to study a long-term historical process of land cover change.This study aims to investigate the spatio-temporal pattern and driving force of land cover change in the Pearl River Delta region in southern China,where the rapid development has been witnessed since 1980s.The fast economic growth has been associated with an accelerated expansion of urban landuse,which has been recorded by historical remote sensing images.This paper reports the method and outcome of the research that attempts to model spatio-temporal pattern of land cover change using multi-temporal satellite images.The classified satellite images were compared to detect the change from various landuse types to built-up areas.The trajectories of land cover change have then been established based on the time-series of the classified land cover classes.The correlation between the expansion of built-up areas and selected economic data has also been analysed for better understanding on the driving force of the rapid urbanisation process.The result shows that,since early 1990s,the dominant trend of land cover change has been from farmland to urban landuse.The relationship between economic growth indicator(measured by GDP)and built-up area can well fit into a linear regression model with correlation coefficients greater than 0.9.It is quite clear that cities or towns have been sprawling in general,demonstrating two growth models that were closely related to the economic development stages.

  7. Technique of optimization of minimum temperature driving forces in the heaters of regeneration system of a steam turbine unit

    Shamarokov, A. S.; Zorin, V. M.; Dai, Fam Kuang


    At the current stage of development of nuclear power engineering, high demands on nuclear power plants (NPP), including on their economy, are made. In these conditions, improving the quality of NPP means, in particular, the need to reasonably choose the values of numerous managed parameters of technological (heat) scheme. Furthermore, the chosen values should correspond to the economic conditions of NPP operation, which are postponed usually a considerable time interval from the point of time of parameters' choice. The article presents the technique of optimization of controlled parameters of the heat circuit of a steam turbine plant for the future. Its particularity is to obtain the results depending on a complex parameter combining the external economic and operating parameters that are relatively stable under the changing economic environment. The article presents the results of optimization according to this technique of the minimum temperature driving forces in the surface heaters of the heat regeneration system of the steam turbine plant of a K-1200-6.8/50 type. For optimization, the collector-screen heaters of high and low pressure developed at the OAO All-Russia Research and Design Institute of Nuclear Power Machine Building, which, in the authors' opinion, have the certain advantages over other types of heaters, were chosen. The optimality criterion in the task was the change in annual reduced costs for NPP compared to the version accepted as the baseline one. The influence on the decision of the task of independent variables that are not included in the complex parameter was analyzed. An optimization task was decided using the alternating-variable descent method. The obtained values of minimum temperature driving forces can guide the design of new nuclear plants with a heat circuit, similar to that accepted in the considered task.

  8. Prescription drug advertising: is it a driving force on drug pricing?

    Millstein, Lloyd G


    It has been shown that drug companies will sell more drugs when they use DTC advertising, but it is also true that many consumers who are suffering--unaware there is help for their symptoms--will learn from these ads that help is available. Advertising to consumers, like advertising to professionals, will continue to be one of the best methods of providing information. Of course, healthcare professionals also have the sales representatives, their colleagues, medical journals, and medical conventions as additional options for needed information. The consumer may or may not use other methods, such as the Internet, the library or friends or family, but the advertising is a starting point for a dialogue. If the DTC ad provides consumers with "information," which is different from "advertising," the drug company will be providing a worthwhile service to consumers and potential patients. No doubt consumers will begin demanding higher quality information from DTC ads and will frown upon the ads that are blatantly trying just to sell a drug. It will also reap the benefits of improved consumer awareness and patient compliance. A DTC ad that is consumer-friendly, does not use fear appeal, is educational in tone, and downplays the "hard sell" and hype will go a long way in offering important information to the casual observer. Oversight by the FDA will ensure the information meets the requirements they have set down for prescription drug advertising. That is, advertising will be truthful and fairly balanced and will meet what the government, consumers and, no doubt, the medical community wants. Attempting to control drug costs, by controlling advertising, will not be an easy task. This has an implication across all product areas, not just drugs. DTC advertising has become a lightening rod for cost containment issues, but is it alone driving demand for prescription products? I don't think so.

  9. Transitions in Land Use Architecture under Multiple Human Driving Forces in a Semi-Arid Zone

    Issa Ouedraogo


    Full Text Available The present study aimed to detect the main shifts in land-use architecture and assess the factors behind the changes in typical tropical semi-arid land in Burkina Faso. Three sets of time-series LANDSAT data over a 23-year period were used to detect land use changes and their underpinning drivers in multifunctional but vulnerable ecologies. Group discussions in selected villages were organized for mapping output interpretation and collection of essential drivers of change as perceived by local populations. Results revealed profound changes and transitions during the study period. During the last decade, shrub and wood savannahs exhibited high net changes (39% and −37% respectively with a weak net positive change for cropland (only 2%, while cropland and shrub savannah exhibited high swap (8% and 16%. This suggests that the area of cropland remained almost unchanged but was subject to relocation, wood savannah decreased drastically, and shrub savannah increased exponentially. Cropland exhibited a null net persistence while shrub and wood savannahs exhibited positive and negative net persistence (1.91 and −10.24, respectively, indicating that there is movement toward agricultural intensification and wood savannah tended to disappear to the benefit of shrub savannah. Local people are aware of the changes that have occurred and support the idea that illegal wood cutting and farming are inappropriate farming practices associated with immigration; absence of alternative cash generation sources, overgrazing and increasing demand for wood energy are driving the changes in their ecosystems. Policies that integrate restoration and conservation of natural ecosystems and promote sustainable agroforestry practices in the study zone are highly recommended.

  10. Spatial pattern of land use change and its driving force in Jiangsu Province.

    Du, Xindong; Jin, Xiaobin; Yang, Xilian; Yang, Xuhong; Zhou, Yinkang


    Scientific interpretation of the mechanism of land use change is important for government planning and management activities. This study analyzes the land use change in Jiangsu Province using three land use maps of 2000, 2005 and 2008. The study results show that there was a significant change in land use. The change was mainly characterized by a continuous built-up land expansion primarily at the expense of cropland loss, and the trend became increasingly rapid. There was an obvious regional difference, as most of the cropland loss or built-up land expansion took place in southern Jiangsu, where the rate of built-up land expansion was faster than in central and northern Jiangsu. Meanwhile, the spatial pattern changed remarkably; in general, the number of patches (NumP) showed a declining trend, and the mean patch size (MPS) and patch size standard deviation (PSSD) displayed increase trends. Furthermore, the relative importance of selected driven factors was identified by principal component analysis (PCA) and general linear model (GLM). The results showed that not only the relative importance of a specific driving factor may vary, but the driven factors may as well. The most important driven factor changed from urban population (UP), secondary gross domestic product (SGDP) and gross domestic product (GDP) during 2000-2005 to resident population (RP), population density (POD) and UP during 2005-2008, and the deviance explained (DE) decreased from 91.60% to 81.04%. Policies also had significant impacts on land use change, which can be divided into direct and indirect impacts. Development policies usually had indirect impacts, particularly economic development policies, which promote the economic development to cause land use change, while land management policies had direct impacts. We suggest that the government should think comprehensively and cautiously when proposing a new development strategy or plan.

  11. Impacts of Human Activity on Biodiversity-An Approach to Driving Force Indicators%人类活动对生物多样性的影响

    Richard Dawson; 曹志平


    The impact of human activity on biodiversity is very complicated, making it difficult to design practical indicators for assessment. Currently, state and response indicators are listed within Chapter 15 of Agenda 21, but no mention is made of driving force indicators and how they relate to biodiversity protection. This paper repre-sents an effort to identify and then operationalize the idea of driving force indicators at national level Five humaninduced factors affecting biodiversity were discussed: (a) habitat loss and fragmentation; (b) overexploitation of resources; (c) species introduction; (d) pollution; and (e) climate change. From these five factors, a subset was selected to serve as possible driving force indicators: (1) habitat loss, (2) the ratio of exotic species to indigenous ones, and (3) the change in pollution status. Although the three indicators are relatively simple, they cover the most important human impacts on biodiversity and offer the potential for further redefinition and ultimate use within the spirit of biodiversity protection.

  12. A Study of the Driving Force Model Revealing Changes in Land Utilization Level Based on 3S Technologies--The Example of Yuanmou, Yunnan, China

    HE Jin-feng; CHEN Guo-jie; YANG Zhong


    This paper introduced the theory and approaches of building driving force models revealing the changes in land utilization level by integrating RS, GPS, and GIS technologies based on the example of Yuanmou County of Yunnan Province. We first created the land utilization type database, natural driving forces for land utilization database, and human driving forces for land utilization database. Then we obtained the dependent and the independent variables of changes in land utilization level by exploring various data. Lastly we screened major factors affecting changes in land utilization level by using the po- werful spatial correlation analysis and main component analysis module of GIS and obtained a multivariable linear regression model of the changes in land utilization level by using GIS spatial regression analysis module.

  13. From Ultrafast Electron Transfer to Single Molecule Spectroscopy: Forces Driving Contemporary Themes in Physical Chemistry

    Landes, Christy


    The goal of the current proposal is to obtain partial support for an upcoming symposium planned for the Fall 2011 American Chemical Society national meeting. The symposium is designed to honor the deceased senior physical chemist and Department of Energy Principle Investigator, Professor Paul Barbara. The primary use of support from DOE’s Basic Energy Sciences division would be to fund registration for postdoctoral and junior scientists, as well as registration and travel support for principle investigators from Primarily Undergraduate Institutions (PUIs). Professor Barbara was particularly adept at mentoring postdoctoral scholars in their transition to independent researchers. DOE support would help to promote the participation of these early career scientists in this symposium. Professor Barbara undertook many projects of considerable importance to the Nation’s energy program; it is hoped that the symposium, beyond honoring him, will also provide an opportunity to discuss the best ways to move forward the unfinished science he initiated with his collaborators.

  14. Evolution of cell populations in vitro: peculiarities, driving forces, mechanisms and consequences

    Kunakh V. A.


    Full Text Available This review outlines the major features and distinctions of cell populations, types and directions of selection in such populations. Population-genetic basis for cell adaptation to growth conditions in vitro is elucidated; in particular, peculiarities of genome evolution in the course of cell dedifferentiation and further cell adaptation to growth conditions in passaged culture are evaluated. Main factors of variation and selection in cell populations in vitro, influence of growth conditions on structure of cell populations and some regularities of cultured cells and regenerated plants are considered. Details of creation of stable cell lines-producers of biologically active substances are presented. Views and suppositions of author resulting from analysis of both literature data and own multiyear studies on cell population genetics are set forth. Among others are substantiated such key statements: cell culture in vitro presents dynamically-heterogeneous biological system, clone population, which is developing (evolving as a result of major driving factors of evolution – variation, heredity, selection and drift of genes (genotypes; interaction between these processes determines the biological characteristics of each particular cell line grown in specific conditions; in adaptation of cells to growth conditions in vitro one can single out three periods: the initial population of isolated cells, the period of strain (cell line formation and the established strain. The division into periods is determined by the type, direction and intensity of «natural» selection that acts in cell population. The formed (adapted to growth in vitro strains are genetically heterogeneous, they are characterized by the presence of physiological and genetic homeostasis, which are mostly caused by the action of stabilizing selection; cultured cells of higher plants are able to synthesize practically all classes of secondary (specialized compounds (alkaloids, steroids

  15. Particle motion in a periodic driving flow. The role of added mass force and the finite size of particles

    Ruiz Chavarria, Gerardo; Lopez Sanchez, Erick Javier


    The motion of particles in a fluid is an open problem. The main difficulty arises from the fact that hydrodynamical forces acting on a particle depend on the flow properties. In addition, the form and the size of particles must be taken into account. In this work we present numerical results of the particle transport in a periodic driving flow in a channel flushing into an open domain. To study the transport of particles we solve the equation of motion for a spherical particle in which we include the drag, the gravity, the buoyancy, the added mass and the history force. Additionally we include the corrections for a particle of finite size. For solving this equation a knowledge of the velocity field is required. To obtain the velocity field we solve the Navier Stokes and the continuity equations with a finite volume method. In the flow under study a vorticity dipole and a spanwise vortex are present, both have an important influence on the motion of particles. The dipole enhances displacement of particles because flow between vortices behaves like a jet and the spanwise vortex produces the lifting and deposition of particles from/to the bottom. We observe clustering of particles both into the channel and in the open domain as observed in coastal systems. The authors acknowledge DGAPA-UNAM by support under project PAPIIT IN115315 "Ondas y estructuras coherentes en dinámica de fluidos".

  16. Apico-basal forces exerted by apoptotic cells drive epithelium folding.

    Monier, Bruno; Gettings, Melanie; Gay, Guillaume; Mangeat, Thomas; Schott, Sonia; Guarner, Ana; Suzanne, Magali


    Epithelium folding is a basic morphogenetic event that is essential in transforming simple two-dimensional epithelial sheets into three-dimensional structures in both vertebrates and invertebrates. Folding has been shown to rely on apical constriction. The resulting cell-shape changes depend either on adherens junction basal shift or on a redistribution of myosin II, which could be driven by mechanical signals. Yet the initial cellular mechanisms that trigger and coordinate cell remodelling remain largely unknown. Here we unravel the active role of apoptotic cells in initiating morphogenesis, thus revealing a novel mechanism of epithelium folding. We show that, in a live developing tissue, apoptotic cells exert a transient pulling force upon the apical surface of the epithelium through a highly dynamic apico-basal myosin II cable. The apoptotic cells then induce a non-autonomous increase in tissue tension together with cortical myosin II apical stabilization in the surrounding tissue, eventually resulting in epithelium folding. Together our results, supported by a theoretical biophysical three-dimensional model, identify an apoptotic myosin-II-dependent signal as the initial signal leading to cell reorganization and tissue folding. This work further reveals that, far from being passively eliminated as generally assumed (for example, during digit individualization), apoptotic cells actively influence their surroundings and trigger tissue remodelling through regulation of tissue tension.

  17. Gravity is indeed the driving force for fault pattern formation and westward displacement of the lithosphere

    Papa, A R R


    Gravity influence of the Sun and the Moon on the Earth is the cause of the fault pattern on Earth's surface we observe nowadays and also of the westward displacement of the lithosphere. A somewhat related hypotheses advanced in the past have been that tidal torque of the Moon may be significant. However, it has been argued that it is untenable essentially on the grounds that the viscosity of the Earth's mantle is far too high in comparison with the forces involved. To state this it was assumed that the Earth's relevant characteristic is that of two spherical shells separated by a viscous liquid, the external shell rotating at a constant angular velocity with respect to the inner shell. Here I show that this picture is not quite right and that a more careful look leads us to one in which both shells rotates at different mean angular velocities and with a forward-backward sequence of movements relative to each other. In this way what was supposed to be the principal factor against gravity influence becomes the ...

  18. Determination of Oxygen Transport Properties from Flux and Driving Force Measurements

    Dalslet, Bjarke Thomas; Søgaard, Martin; Hendriksen, Peter Vang


    We demonstrate that an electrolyte probe can be used to measure the difference in oxygen chemical potential across the surface, when an oxygen flux is forced through an oxygen permeable membrane disk. The oxygen flux as well as the total oxygen chemical potential difference is carefully controlled...... by an oxygen pump. The developed method is tested on a (La0.6Sr0.4)0.99Co0.2Fe0.8O3−delta membrane. An La0.75Sr0.25MnO3/Y0.16Zr0.84O1.92/La0.75Sr0.25MnO3 oxygen pump was attached to one side of the membrane. A conical Ce0.9Gd0.1O1.95 (CG10) electrolyte probe was pressed against the other side of the membrane....... The voltage difference between the base and the tip of the CG10 probe was recorded with an applied oxygen flux through the membrane. This voltage was used to extract precise values of the surface exchange rate constant, kO. Using these values of kO, the vacancy diffusion factor, Dv0, could be extracted from...

  19. [The driving force in the thinking of Norbert Elias. An attempt at psychoanalytic interpretation].

    Schröter, M


    The theory of civilization proposed by the eminent sociologist Norbert Elias, who died in 1990, has its roots in Freud's theory of culture. Elias always denied the importance of personal factors in connection with his work, but as has been demonstrated in connection with artists such as Leonardo da Vinci and indeed Freud himself, this does not make it any the less legitimate to go in search of those infantile/unconscious motifs and affective sources powering Elias' prodigious scholarly creativity and informing his work, in however sublimated a form. Proceeding from the observation that successful scholarly or artistic production represents a synthesis of the forces of id, ego and super-ego, i.e. of affect, knowledge and conscience, the author demonstrates that concerns of central moment to Elias' thinking--commitment and non-involvement, establishment and outsider, the restraining of aggression in the civilizational process, interdependence of individuals--are partly the product of early experiences which Elias was able to turn to fruitful account in his work.

  20. Supply Chain Management as a Driving Force for Generating Competitive Advantage for Dairy Companies

    Irina Olegovna Poleshkina


    Full Text Available The study aims to uncover the reserves to generate competitive advantages for the participants of the market of perishables in the case of the dairy sector due to the formation of effective supply chains, as this category of goods is the most demanding in terms of periods and conditions of transportation and terms of preservation. The research technique is based on the concepts of value chains and supply chain management. In order to optimize the distribution of functions between the participants of the dairy chain a process-based approach has been applied. The research has revealed the main reasons for high aggregate costs and the places of their formation at each stage of the dairy supply chain. The article proposes the mechanisms to address three main problems arising from the process of building relations between the participants of the dairy supply chain in Russia. These problems are associated with a disproportionate margin distribution between the participants of the chain, with non-compliance of the quality of raw milk with the requirements for the production of specific types of dairy products, and with distrust of the supply chain participants, which increases transaction costs and forces to create reserve supplies which reduce the competitiveness of the whole dairy supply chain in general. In order to improve the competitiveness of all participants in the dairy chain, the article presents several mechanisms for solving these problems. The first is margin distribution based on the costs incurred by each participant of the dairy chain. The second is the use of a mathematical model to determine the assortment of goods of a dairy enterprise on the basis of the incoming volume and quality of raw milk according to the seasonal factor and the demand for dairy products. The third is the feasibility of refusal from the formation of reserve supplies by all participants of the dairy chain, which will not only minimize aggregate costs, but also

  1. 旅游流驱动力系统分析%Study on the driving force of tourist flows

    杨兴柱; 顾朝林; 王群


    旅游流是旅游现象和旅游业的基础,也是旅游地理研究的核心问题之一.针对目前国内旅游流驱动力系统研究的薄弱环节,从旅游流空间分布简单描述转向多学科视角的机制探讨,采用文献分析法和系统归纳法,深入剖析旅游流驱动机制,构建旅游流的驱动机制概念模型.旅游流形成理论基础涉及心理学的推拉理论、经济学的需求理论、地理学的空间相互作用理论等.旅游流驱动力包括旅游者的外在驱动力、旅游需求的外在动力、旅游供给的外在动力、距离阻力、惯性力、空间结构力等.结合旅游流形成的理论基础和驱动力,构建了旅游流驱动机制概念模型.概念模型反映了形成旅游流的动力来自旅游活动系统内部和外部两个方面,由客源地旅游需求推动和旅游地吸引所构成,同时还受两地阻力、客源地与目的地空间结构影响.概念模型也体现了综合性、整体性,是动态发展变化的.%Tourist flow is the basis of the tourism phenomenon and tourism industry, but also one of the core issues in tourism geography. However, the driving force of tourist flows is still under-explored. How to achieve shift from a brief description of the spatial distribution of tourist flows to mechanism? On the basis of document analysis and system induction method, this paper analyzed the driving force of tourist flows, and built the driving mechanism conceptual model of tourist flows from the multi-disciplinary perspective.The theoretical basis on tourist flow included push-pull theory, demand theory, spatial interaction theory, competitiveness theory etc. Although these theories can explain tourist flows, there are relatively few systematic and comprehensive multi-disciplinary studies. As for the driving mechanism of the tourist flow, the authors found that the formation mechanism of the tourist flow has not yet been systematically studied. Scholars attach importance

  2. Both Ca2+-permeable and -impermeable AMPA receptors contribute to primary synaptic drive onto rat dorsal horn neurons

    Tong, Chi-Kun; MacDermott, Amy B


    Blockade of Ca2+-permeable AMPA receptors in the rat spinal cord diminishes the development of hyperalgesia and allodynia associated with peripheral injury. Cobalt uptake studies reveal that Ca2+-permeable AMPA receptors are expressed by some substance P receptor-expressing (NK1R+) neurons in lamina I, as well as other neurons throughout the superficial dorsal horn. Selective elimination of NK1R+ neurons in lamina I and lamina III/IV of the dorsal horn also suppresses development of hyperalgesia and allodynia. These observations raise the possibility that Ca2+-permeable AMPA receptors contribute to excitatory synaptic drive onto the NK1R+ neurons associated with allodynia and hyperalgesia. The first synapse in the pain pathway is the glutamatergic excitatory drive from the primary afferent fibres onto dorsal horn neurons. Therefore, we tested whether Ca2+-permeable AMPA receptors are located on lamina I and lamina III/IV NK1R+ neurons postsynaptic to primary afferent fibres, using inward rectification and polyamine toxins for receptor identification. We examined three different populations of dorsal horn neurons; lamina I NK1R+ neurons, including projection neurons, and non-NK1R+ (NK1R−) neurons including interneurons, and lamina III/IV NK1R+ neurons, believed to contribute to the low-threshold mechanosensory pathway. The majority of synapses in all three groups had rectification indices less than 1.0 and greater than 0.4, indicating that the AMPA receptors at these synapses are a mixture of Ca2+-permeable and -impermeable forms. Lamina III/IV NK1R+ neurons and lamina I NK1R− neurons have a significantly higher proportion of postsynaptic Ca2+-permeable AMPA receptors than lamina I NK1R+ neurons. Thus synaptically positioned Ca2+-permeable AMPA receptors directly contribute to low-threshold sensory afferent drive into the dorsal horn, and can mediate afferent input onto interneurons such as GABAergic neurons. These receptors also contribute to high

  3. Multi Satellites Monitoring of Land Use/Cover Change and Its Driving Forces in Kashgar Region, China

    Maimaitiaili, Ayisulitan; Aji, xiaokaiti; Kondoh, Akihiko


    Multi Satellites Monitoring of Land Use/Cover Change and Its Driving Forces in Kashgar Region, China Ayisulitan Maimaitiaili1, Xiaokaiti Aji2 Akihiko Kondoh2 1Graduate School of Science, Chiba University, Japan 2Center for Environmental Remote Sensing, Chiba University The spatio-temporal changes of Land Use/Cover (LUCC) and its driving forces in Kashgar region, Xinjiang Province, China, are investigated by using satellite remote sensing and a geographical information system (GIS). Main goal of this paper is to quantify the drivers of LUCC. First, considering lack of the Land Cover (LC) map in whole study area, we produced LC map by using Landsat images. Land use information from Landsat data was collected using maximum likelihood classification method. Land use change was studied based on the change detection method of land use types. Second, because the snow provides a key water resources for stream flow, agricultural production and drinking water for sustaining large population in Kashgar region, snow cover are estimated by Spot Vegetation data. Normalized Difference Snow Index (NDSI) algorithm are applied to make snow cover map, which is used to screen the LUCC and climate change. The best agreement is found with threshold value of NDSI≥0.2 to generate multi-temporal snow cover and snowmelt maps. Third, driving forces are systematically identified by LC maps and statistical data such as climate and socio-economic data, regarding to i) the climate changes and ii) socioeconomic development that the spatial correlation among LUCC, snow cover change, climate and socioeconomic changes are quantified by using liner regression model and negative / positive trend analysis. Our results showed that water bodies, bare land and grass land have decreasing notably. By contrast, crop land and urban area have continually increasing significantly, which are dominated in study area. The area of snow/ice have fluctuated and has strong seasonal trends, total annual snow cover

  4. Toward a Theory of Island Pedogeography: Testing the driving forces for pedological assemblages in archipelagos of different origins

    Ibáñez, Juan-José; Effland, William R.


    The Theory of Island Biogeography has been based on biodiversity studies and used as a powerful predictive tool. Currently pedogeography does not have a similar theoretical construct. Although island biodiversity and biological assemblages have been topics of widespread interest in biogeography, ecology and conservation biology, soil scientists have conducted few studies of pedodiversity and pedological assemblages in archipelagos. Several studies have demonstrated that pedodiversity and biodiversity patterns have striking similarities in very disparate environments and at different scales, thus it is possible to test for a similar construct of island pedogeography. We analyze similarities and differences in the pedosphere for three archipelagos with different origins: (i) oceanic-intra-plate chains islands (Hawaiian Islands), (ii) oceanic-intra-plate cluster islands (Canary Islands), (iii) non-marine land-bridge islands with volcanism associated with plate boundary conditions (Aegean Islands) and (iv) as a comparison, islands in a nonplate boundary setting (the British Isles). In the Canary Islands, we also compiled selected biological, physiographical, geological and climatic data for further analysis of pedodiversity, climatic diversity, geodiversity and biodiversity. Our pedogeographic analysis of the three archipelagos indicates archipelagos of varying origins contain different soil assemblages with plate tectonics as the main driving force. The similarities between pedodiversity and biodiversity are more remarkable than the differences. We tested the hypothesis that soil taxa distributions on island chains can be modelled as a power function similar to the species-area relationship (SAR) proposed by McArthur and Wilson for archipelagos. The SAR functional relationship has been widely corroborated in other biodiversity studies. The same patterns were obtained for pedodiversity and biodiversity in the British Isles, and after that in the Aegean Archipelago. In

  5. Analysis on the multi-dimensional spectrum of the thrust force for the linear motor feed drive system in machine tools

    Yang, Xiaojun; Lu, Dun; Ma, Chengfang; Zhang, Jun; Zhao, Wanhua


    The motor thrust force has lots of harmonic components due to the nonlinearity of drive circuit and motor itself in the linear motor feed drive system. What is more, in the motion process, these thrust force harmonics may vary with the position, velocity, acceleration and load, which affects the displacement fluctuation of the feed drive system. Therefore, in this paper, on the basis of the thrust force spectrum obtained by the Maxwell equation and the electromagnetic energy method, the multi-dimensional variation of each thrust harmonic is analyzed under different motion parameters. Then the model of the servo system is established oriented to the dynamic precision. The influence of the variation of the thrust force spectrum on the displacement fluctuation is discussed. At last the experiments are carried out to verify the theoretical analysis above. It can be found that the thrust harmonics show multi-dimensional spectrum characteristics under different motion parameters and loads, which should be considered to choose the motion parameters and optimize the servo control parameters in the high-speed and high-precision machine tools equipped with the linear motor feed drive system.

  6. Spatiotemporal Pattern and Driving Forces of Arable Land-Use Intensity in China: Toward Sustainable Land Management Using Emergy Analysis

    Hualin Xie


    Full Text Available The level of arable land-use intensity has important impacts on food security and rural sustainable development. Using the emergy method, we investigate the spatial disparities and driving forces of arable land-use intensity in China from 1999 to 2008 at the national, regional and provincial levels. The empirical results show that chemical fertilizer was the largest component of agricultural inputs and that agricultural diesel oil recorded the highest growth rate. The degree of heterogeneities in arable land-use intensity in China showed a decreasing trend, which resulted mainly from the differences among the eastern, northeastern, central and western regions. The regional disparities in labor, pesticides and plastic sheeting decreased from 1999 to 2008. The per capita annual net incomes of household operations and the agricultural policies had a significant positive correlation with total inputs, fertilizer inputs, pesticide inputs and agricultural plastic sheeting. In addition, the nonagricultural population had a greater impact on agricultural plastic sheeting. Finally, we suggest that there is an urgent need to focus on the effects of chemical fertilizer and pesticide inputs on the ecological environment. Agricultural support policies should be introduced for the poor agricultural production provinces.

  7. Analysis of the Influencing Factors and Key Driving Force concerning the Efficiency of Green Supply Chain of Fruits and Vegetables

    Yingtang; LI; Zhong; QIAO


    Like the general green supply chain,the green supply chain of fruits and vegetables also requires low negative effects of the environment and high resource utilization rate,as well as the healthiness and freshness of fruits and vegetables.Currently,the level of development of the green supply chain of fruits and vegetables is low in China,and the freshness of fruits and vegetables can not be well maintained,so there is an urgent need to improve the operational efficiency of the green supply chain of fruits and vegetables.The operational efficiency of the green supply chain of fruits and vegetables is affected by many factors,and the most important factor is the incomplete consistency between the individual interests of supply chain members and the overall interests of supply chain.Therefore,the key driving force to improve the efficiency of green supply chain of fruits and vegetables is to build the scientific and rational collaborative decision-making mechanism of supply chain,in order to solve the problems concerning the green supply chain of fruits and vegetables,such as risk sharing,cost control and revenue allocation,thereby achieving the coordinated development of the green supply chain of fruits and vegetables.

  8. Invasion of Nostocales (cyanobacteria to subtropical and temperate freshwater lakes – Physiological, regional and global driving forces

    Assaf eSukenik


    Full Text Available Similarly to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases regional changes in nutrient loads and in biotic conditions were attributed to the invasion events

  9. The Driving Forces for the Practice of Strategic Planning in SMEs: Evidence from Harare Metropolitan Province, Zimbabwe

    Maxwell Sandada


    Full Text Available Despite Zimbabwe sharing with the rest of the world, the notion that SMEs are the impeccable engines to economic revival, growth and development, many of the nation`s SMEs are plagued with high failure rates. Previous studies carried out in most foreign countries suggested that the high failure rate of SMEs was attributable to lack of strategic planning among a host of other factors. Against this backdrop, the purpose of this study was to examine the driving forces for the practice of strategic planning in SMEs. A quantitative cross sectional study was conducted among active SMEs who are registered with the Ministry of Small and Medium Enterprises and Cooperative Development in Zimbabwe. The study revealed that globalisation, business ownership motivations, environmental dynamism and innovation & technological advancement have a positive and statistically significant influence on the adoption or practice of strategic planning among SMEs. The study has important implications for the practice and implementation of strategic planning among SMEs especially in the context of a developing country such as Zimbabwe.

  10. A microfluidic device based on gravity and electric force driving for flow cytometry and fluorescence activated cell sorting.

    Yao, Bo; Luo, Guo-an; Feng, Xue; Wang, Wei; Chen, Ling-xin; Wang, Yi-ming


    A novel method based on gravity and electric force driving of cells was developed for flow cytometry and fluorescence activated cell sorting in a microfluidic chip system. In the experiments cells flowed spontaneously under their own gravity in a upright microchip, passed through the detection region and then entered into the sorting electric field one by one at an average velocity of 0.55 mm s(-1) and were fluorescence activated cell sorted (FACS) by a switch-off activation program. In order to study the dynamical and kinematic characteristics of single cells in gravity and electric field of microchannels a physical and numerical module based on Newton's Law of motion was established and optimized. Hydroxylpropylmethyl cellulose (HPMC) was used to minimize cell assembling, sedimentation and adsorption to microchannels. This system was applied to estimate the necrotic and apoptotic effects of ultraviolet (UV) light on HeLa cells by exposing them to UV radiation for 10, 20 or 40 min and the results showed that UV radiation induced membrane damage contributed to the apoptosis and necrosis of HeLa cells.

  11. Driving forces in energy-related CO2 emissions in south and east coastal China: commonality and variations

    Gao, C.; Liu, Y.; Jin, J.; Wei, T.


    East and south coastal China contributes to respectively about 30% and 8% of CO2 emissions in China and the world, and therefore play a critical role in achieving the national goal of emission reduction to mitigate the global warming. It also serves as a benchmark for the less developed regions of China, in terms of achieving the developed world's human development standard under lower per capita emissions. We analyze the driving forces of emissions in this region and their provincial characteristics by applying the Logarithmic Mean Divisia Index method. Our findings show that emissions have been doubled during the period from 2000 to 2012, along with three and two folds increase in economy and energy consumption, respectively. This suggests a persistent lock between economic growth and emissions, even in this socioeconomically advanced region in China. Provincial difference in annual emission growth reveals three distinguished low-carbon developmental stages, owning mainly to the effectiveness of energy efficiency in reducing emission growth. This may explain why previous climate policies have aimed to reduce carbon intensity. These results indicate that targeted measures on enhancing energy efficiency in the short term and de-carbonization of both the economic and energy structure in the long term can lower the emission growth more effectively and efficiently. They also suggest that factor-driven emission reduction strategies and policies are needed in the geographically and socioeconomically similar regions.

  12. Entropy-enthalpy transduction caused by conformational shifts can obscure the forces driving protein-ligand binding.

    Fenley, Andrew T; Muddana, Hari S; Gilson, Michael K


    Molecular dynamics simulations of unprecedented duration now can provide new insights into biomolecular mechanisms. Analysis of a 1-ms molecular dynamics simulation of the small protein bovine pancreatic trypsin inhibitor reveals that its main conformations have different thermodynamic profiles and that perturbation of a single geometric variable, such as a torsion angle or interresidue distance, can select for occupancy of one or another conformational state. These results establish the basis for a mechanism that we term entropy-enthalpy transduction (EET), in which the thermodynamic character of a local perturbation, such as enthalpic binding of a small molecule, is camouflaged by the thermodynamics of a global conformational change induced by the perturbation, such as a switch into a high-entropy conformational state. It is noted that EET could occur in many systems, making measured entropies and enthalpies of folding and binding unreliable indicators of actual thermodynamic driving forces. The same mechanism might also account for the high experimental variance of measured enthalpies and entropies relative to free energies in some calorimetric studies. Finally, EET may be the physical mechanism underlying many cases of entropy-enthalpy compensation.

  13. Characteristics of secondary migration driving force of tight oil and its geologic effect: a case study of Jurassic in Central Sichuan Basin

    Pang, Zhenglian; Tao, Shizhen; Zhang, Bin; Wu, Songtao; Yang, Jiajing; Chen, Ruiyin


    As the rising of its production, tight oil is becoming more and more important. Much research has been done about it. Some articles mention that buoyancy is ineffective for tight oil secondary migration, and abnormal pressure is the alternative. Others believe that overpressure caused hydrocarbon generation is the very force. Though opinions have been given, there are two inadequacies. Firstly, the points are lack of sufficient evidences. Mostly, they are only one or two sentences in the papers. Secondly, geologic effect of the change of driving force hasn't been discussed. In this context, analog experiments, physical property testing, mercury injection, and oil/source comparison were utilized to study 3 issues: origin and value of tight oil secondary migration resistance, values and effectiveness of different potential driving forces, and geologic effect of tight oil secondary migration driving force. Firstly, resistance values of tight reservoir were detected by analog experiments. The value of tight limestone is 15.8MPa, while tight sandstone is 10.7MPa. Tiny size of pores and throats in tight reservoir is the main reason causing huge resistances. Over 90% of pores and throats in tight reservoir are smaller than 1μm. They form huge capillary force when oil migrating through them. Secondly, maximum of buoyancy in study area was confirmed, 0.09MPa, too small to overcome the resistances. Meanwhile, production data suggests that tight oil distribution pattern is not controlled by buoyancy. Conversely, analog experiment proves that overpressure caused by hydrocarbon generation can reach 38MPa, large enough to be the driving force. This idea is also supported by positive correlation between output and source rock formation pressure. Thirdly, is the geologic effect of tight oil secondary migration resistance and driving force. Tight oil can migrate only as non-darcy flow due to huge resistances according to percolation experiments. It needs to overcome the starting

  14. The Driving Force

    Liu Zhiyang


    There is a popular aphorism in China,"The third-class enterprise produces products,the second-class creates brands,and the first-class develops standards".This shows that Standardization has been heavily emphasized in China.As the super large govemment-owned enterprise,the State Grid Corporation of China (SGCC) bears the mission of providing public energy and implementing social responsibility with the construction and operation of national power grid as its core business,SGCC has been always paying great attention to the standardization work since its establishment,and made outstanding achievements in both standardization and corporate development,ranked 7th in the FORTUNE GLOBAL 500 in 2011.

  15. Translation to Primary Care of an Effective Teen Safe Driving Program for Parents.

    Shope, Jean T; Zakrajsek, Jennifer S; Finch, Stacia; Bingham, C Raymond; O'Neil, Joseph; Yano, Stephen; Wasserman, Richard; Simons-Morton, Bruce


    Addressing teen driver crashes, this study adapted an effective Checkpoints(TM) program for parents of teen drivers for dissemination by primary care practitioners (PCPs) and the web; distributed the PCP/web program through pediatric practices; and examined dissemination to/implementation by parents. The website,, and brief intervention protocol were developed. PCPs delivered interventions and materials to parents, referred them to the website, and completed follow-up surveys. Google Analytics assessed parents' website use. Most PCPs reported delivering interventions with fidelity, and thought the program important and feasible. Brief interventions/website referrals, averaging 4.4 minutes, were delivered to 3465 (87%) of 3990 eligible parents by 133 PCPs over an 18-week average. Website visits (1453) were made by 42% of parents, who spent on average 3:53 minutes viewing 4.2 topics. This program costs little (its website, training and promotional materials are available) and could be one component of a comprehensive approach to reducing teen driver crashes. © The Author(s) 2016.

  16. Land use and land cover change and its driving forces in Maqu County, China in the past 25 years

    JunFeng Lu; ZhiBao Dong; GuangYin Hu; WenJin Li; WanYin Luo; MingLiang Tan


    Maqu County is located in the northeast Qinghai-Tibetan Plateau, and it is the main watershed for the Yellow River. The ecosystem there is extremely vulnerable and sensitive to climate change and human activities, which have caused significant deterioration of the eco-environment in this region. In order to restore the ecological environment, a government project to restore the grazing areas to grassland was implemented in Maqu County in early 2004. This study evaluates the effects of that restoration project on land use and land cover change (LUCC), and explores the driving forces of LUCC in Maqu County. In the study we used Landsat images obtained in 1989, 2004, 2009, and 2014 to establish databases of land use and land cover. Then we derived LUCC information by overlaying these layers using GIS software. Finally, we analyzed the main forces responsible for LUCC. The results showed that forests, high-coverage grasslands, and marshes experienced the most signif-icant decreases during 1989–2004, by 882.8 ha, 35,250.4 ha, and 2,753.4 ha, respectively. However, moderate- and low-coverage grasslands and sand lands showed the opposite trend, increasing by 12,529.7 ha, 25,491.0 ha, and 577.5 ha, respectively. LUCC in 2004–2009 showed that ecological degradation slowed compared with 1989−2004. During 2009–2014, high- and moderate-coverage grasslands increased obviously, but low-coverage grasslands, marshes, unused lands, sand lands, and water areas showed the opposite trend. These results suggested that the degradation of the eco-environment was obvious before 2009, showing a decrease in the forests, grasslands, and water areas, and an increase in unused lands. The ecological degradation was reversed after 2009, as was mainly evidenced by increases in high-and mod-erate-coverage grasslands, and the shrinkage rate of marshes decreased obviously. These results showed that the project of restoring grazing lands to grassland had a positive effect on the LUCC. Other

  17. Comparison of the driving forces of spring phenology among savanna landscapes by including combined spatial and temporal heterogeneity.

    Zhu, Likai; Southworth, Jane; Meng, Jijun


    Understanding spatial and temporal dynamics of land surface phenology (LSP) and its driving forces are critical for providing information relevant to short- and long-term decision making, particularly as it relates to climate response planning. With the third generation Global Inventory Monitoring and Modeling System (GIMMS3g) Normalized Difference Vegetation Index (NDVI) data and environmental data from multiple sources, we investigated the spatio-temporal changes in the start of the growing season (SOS) in southern African savannas from 1982 through 2010 and determined its linkage to environmental factors using spatial panel data models. Overall, the SOS occurs earlier in the north compared to the south. This relates in part to the differences in ecosystems, with northern areas representing high rainfall and dense tree cover (mainly tree savannas), whereas the south has lower rainfall and sparse tree cover (mainly bush and grass savannas). From 1982 to 2010, an advanced trend was observed predominantly in the tree savanna areas of the north, whereas a delayed trend was chiefly found in the floodplain of the north and bush/grass savannas of the south. Different environmental drivers were detected within tree- and grass-dominated savannas, with a critical division being represented by the 800 mm isohyet. Our results supported the importance of water as a driver in this water-limited system, specifically preseason soil moisture, in determining the SOS in these water-limited, grass-dominated savannas. In addition, the research pointed to other, often overlooked, effects of preseason maximum and minimum temperatures on the SOS across the entire region. Higher preseason maximum temperatures led to an advance of the SOS, whereas the opposite effects of preseason minimum temperature were observed. With the rapid increase in global change research, this work will prove helpful for managing savanna landscapes and key to predicting how projected climate changes will affect

  18. Free energy partitioning analysis of the driving forces that determine ion density profiles near the water liquid-vapor interface.

    Arslanargin, Ayse; Beck, Thomas L


    Free energy partitioning analysis is employed to explore the driving forces for ions interacting with the water liquid-vapor interface using recently optimized point charge models for the ions and SPC/E water. The Na(+) and I(-) ions are examined as an example kosmotrope/chaotrope pair. The absolute hydration free energy is partitioned into cavity formation, attractive van der Waals, local electrostatic, and far-field electrostatic contributions. We first compute the bulk hydration free energy of the ions, followed by the free energy to insert the ions at the center of a water slab. Shifts of the ion free energies occur in the slab geometry consistent with the SPC/E surface potential of the water liquid-vapor interface. Then the free energy profiles are examined for ion passage from the slab center to the dividing surface. The profiles show that, for the large chaotropic I(-) ion, the relatively flat total free energy profile results from the near cancellation of several large contributions. The far-field electrostatic part of the free energy, largely due to the water liquid-vapor interface potential, has an important effect on ion distributions near the surface in the classical model. We conclude, however, that the individual forms of the local and far-field electrostatic contributions are expected to be model dependent when comparing classical and quantum results. The substantial attractive cavity free energy contribution for the larger I(-) ion suggests that there is a hydrophobic component important for chaotropic ion interactions with the interface.

  19. Nutrient limitation drives response of Calamagrostis epigejos to arbuscular mycorrhiza in primary succession.

    Rydlová, Jana; Püschel, David; Dostálová, Magdalena; Janoušková, Martina; Frouz, Jan


    Little is known about the functioning of arbuscular mycorrhizal (AM) symbiosis over the course of primary succession, where soil, host plants, and AM fungal communities all undergo significant changes. Over the course of succession at the studied post-mining site, plant cover changes from an herbaceous community to the closed canopy of a deciduous forest. Calamagrostis epigejos (Poaceae) is a common denominator at all stages, and it dominates among AM host species. Its growth response to AM fungi was studied at four distinctive stages of natural succession: 12, 20, 30, and 50 years of age, each represented by three spatially separated sites. Soils obtained from all 12 studied sites were γ-sterilized and used in a greenhouse experiment in which C. epigejos plants were (1) inoculated with a respective community of native AM fungi, (2) inoculated with reference AM fungal isolates from laboratory collection, or (3) cultivated without AM fungi. AM fungi strongly boosted plant growth during the first two stages but not during the latter two, where the effect was neutral or even negative. While plant phosphorus (P) uptake was generally increased by AM fungi, no contribution of mycorrhizae to nitrogen (N) uptake was recorded. Based on N:P in plant biomass, we related the turn from a positive to a neutral/negative effect of AM fungi on plant growth, observed along the chronosequence, to a shift in relative P and N availability. No functional differences were found between native and reference inocula, yet root colonization by the native AM fungi decreased relative to the reference inoculum in the later succession stages, thereby indicating shifts in the composition of AM fungal communities reflected in different functional characteristics of their members.

  20. Innate immunity drives the initiation of a murine model of primary biliary cirrhosis.

    Chao-Hsuan Chang

    Full Text Available Invariant natural killer T (iNKT cells play complex roles in bridging innate and adaptive immunity by engaging with glycolipid antigens presented by CD1d. Our earlier work suggested that iNKT cells were involved in the initiation of the original loss of tolerance in primary biliary cirrhosis (PBC. To address this issue in more detail and, in particular, to focus on whether iNKT cells activated by a Th2-biasing agonist (2s,3s,4r-1-O-(α-D-galactopyranosyl-N-tetracosanoyl-2-amino-1,3,4-nonanetriol (OCH, can influence the development of PBC in a xenobiotic-induced PBC murine model. Groups of mice were treated with either OCH or, as a control, α-galactosylceramide (α-GalCer and thence serially followed for cytokine production, markers of T cell activation, liver histopathology and anti-mitochondrial antibody responses. Further, additional groups of CD1d deleted mice were similarly studied. Our data indicate that administration of OCH has a dramatic influence with exacerbation of portal inflammation and hepatic fibrosis similar to mice treated with α-GalCer. Further, iNKT cell deficient CD1d knockout mice have decreased inflammatory portal cell infiltrates and reduced anti-mitochondrial antibody responses. We submit that activation of iNKT cells can occur via overlapping and/or promiscuous pathways and highlight the critical role of innate immunity in the natural history of autoimmune cholangitis. These data have implications for humans with PBC and emphasize that therapeutic strategies must focus not only on suppressing adaptive responses, but also innate immunity.

  1. H2O-rich melt inclusions in fayalitic olivine from Hekla volcano: Implications for phase relationships in silicic systems and driving forces of explosive volcanism on Iceland

    Portnyagin, Maxim; Hoernle, Kaj; Storm, Sonja; Mironov, Nikita; van den Bogaard, Christel; Botcharnikov, Roman


    Silicic Icelandic magmas are widely believed to contain low to moderate H2O content prior to degassing, and that their high explosivity mostly results from the interaction of the magmas with ice or meteoric water. Here we report the compositions of glass inclusions (SiO2=57-72 wt%, K2O=1.3-2.6 wt%) in Fe-rich olivines (Fo2-42) from the largest Holocene eruptions of Hekla volcano (H3 and H4) on Iceland, which preserved quenched melts with very high primary H2O contents (3.3-6.2 wt%). The silicic Hekla melts originate primarily by extensive (˜90%) crystal fractionation of H2O-poor (˜0.6 wt%) basalts and represent an end member in the systematics of terrestrial magmas because they originate at low fO2 (ΔQFM ˜-0.1 to -0.4) and have as high H2O contents as significantly more oxidized island-arc magmas (ΔQFM≥1). This demonstrates that H2O and ΔQFM do not correlate in silicic magmas from different tectonic settings, and that fO2, not H2O content, shows a major difference between silicic ocean-island (e.g., Icelandic) and island-arc magmas. Analysis of available experimental data suggests that high H2O activity and low fO2 expand the field of olivine stability in silicic melts. Low fO2 and low MgO content could also suppress crystallization of amphibole. On the basis of these results we propose that an anhydrous mineral assemblage bearing Fe-rich olivine in evolved volcanic and Skaergaard-type intrusive rocks does not imply low H2O in magmas prior to degassing but, in contrast to the commonly held view, is an indicator of H2O-rich silicic parental magmas crystallized at low fO2. Finally, the high H2O content in magma was a major driving force of the largest explosive eruptions of Hekla volcano and must be at least as important for driving silicic explosive volcanism on Iceland as magma-ice interaction.


    张常亮; 李同录; 李萍


    The common two-dimensional(2D)methods for the driving forces of landslides don't consider the lateral variation and confinements,which can make the stabilization design un-precisely. Three-dimensional(3D) method can reflect the spatialdistribution of the driving force of landslide. So it can resolve the problem of 2D methods. This paper provides a general formula for calculating the driving force of 3D landslide. It is based on the method of the general form of 3D equilibrium proposed by the authors. The paper presents case studies and a comparison between the 2D and 3D methods. Then,it obtains a distribution function of the lateral variation. This function reflects the spatial distribution of the driving force of 3D landslides,and makes slope stabilization design more reasonable.%常规二维滑坡推力计算没有考虑其横向变化,导致设计过于保守,三维推力计算方法的提出则能体现滑坡推力的空间分布,解决二维存在的问题.本文在三维极限平衡法统一模型的基础上,建立了求解三维滑坡推力的统一公式.利用实例,通过二维推力计算与三维计算结果的对比分析,获得三维推力的横向分布函数,有效反映出三维滑坡推力的空间分布状态,所得三维滑坡推力应用于设计更合理.

  3. Optimization of single-cell electroporation protocol for forced gene expression in primary neuronal cultures.

    Nishikawa, Shin; Hirashima, Naohide; Tanaka, Masahiko


    The development and function of the central nervous system (CNS) are realized through interactions between many neurons. To investigate cellular and molecular mechanisms of the development and function of the CNS, it is thus crucial to be able to manipulate the gene expression of single neurons in a complex cell population. We recently developed a technique for gene silencing by introducing small interfering RNA into single neurons in primary CNS cultures using single-cell electroporation. However, we had not succeeded in forced gene expression by introducing expression plasmids using single-cell electroporation. In the present study, we optimized the experimental conditions to enable the forced expression of green fluorescent protein (GFP) in cultured cerebellar Purkinje neurons using single-cell electroporation. We succeeded in strong GFP expression in Purkinje neurons by increasing the inside diameter of micropipettes or by making the size of the original plasmid smaller by digestion and cyclizing it by ligation. Strong GFP expression in Purkinje neurons electroporated under the optimal conditions continued to be observed for more than 25 days after electroporation. Thus, this technique could be used for forced gene expression in single neurons to investigate cellular and molecular mechanisms of the development, function, and disease of the CNS.

  4. [Spatio-temporal change of sand-fixing function and its driving forces in desertification control ecological function area of Hunshandake, China].

    Shen, Lu; Tian, Mei-rong; Gao, Ji-xi; Qian, Jin-ping


    Soil erosion is an important ecological and environmental problem in Hunshandake Desert, and the sand-fixing function determines the degree of ecological security in the entire region. In order to clarify the situation of windbreak and sand fixation in Hunshandake area, and to guide the prevention and treatment of desertification on regional scale, based on the meteorological and remote sensing data, this paper quantitatively analyzed the temporal and spatial pattern of windbreak and sand fixation ability between 2000-2010 by the revised wind erosion equation (RWEQ) model, meanwhile, the driving forces for each county ( or banner) in the functional zone were analyzed with the method of principal component analysis. The results showed that there was a fluctuation of the sand fixing capacity in Hunshandake over time, generally rendering a decline trend. The coniferous forest and grassland had strong windbreak and sand fixation capacity in unit area among the various land categories. In terms of spatial distribution, the windbreak and sand fixation function in western and southeastern region was weak and needed to be strengthened with ecological restoration efforts. Through the study of the social driving forces of each administrative region in the function zone, there were 3 main social driving forces of soil erosion in the administrative functions: the intensity of input-output, the level of economic development and the level of agriculture-husbandry development.

  5. Force

    Graybill, George


    Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

  6. Mediterranean coastal dune vegetation: Are disturbance and stress the key selective forces that drive the psammophilous succession?

    Ciccarelli, Daniela


    Plant communities of coastal dunes are distributed along a characteristic sea-inland gradient. Generally, there is a shift from annual and short height species with small leaves in the initial successional stages to perennial tall shrubs with tough leaves in later phases. Assessing the community-weighted mean (CWM) trait values is used in plant ecology to describe ecosystem properties especially during succession. In particular, CSR (Competitive, Stress-tolerant, and Ruderal strategy) classification allows us to explore community functional shifts in terms of disturbance, stress and competition selective forces. The functional basis of the psammophilous succession was studied based on the following questions: (1) Can we circumscribe different functional types among plant species of Mediterranean coastal dunes? (2) How do CWM trait values vary along the environmental sea-inland gradient? (3) What is the relative importance of competition, stress and disturbance in the processes of plant community assembling? (4) Can we postulate that along primary successions there is generally a shift from ruderality to stress-tolerance? An explorative analysis of functional groups was performed by Non-Metric Multidimensional Scaling (NMDS) analysing nine morpho-functional traits measured for 45 taxa from 880 dune plots localised in Tuscany (central Italy, Europe). NMDS ordination showed a scattered distribution of psammophytes that could not be delimited in precise plant functional types. The first NMDS axis has been interpreted as a leaf economics axis because it was correlated to leaf area (LA) and leaf dry matter content (LDMC), while the second one was a plant size axis because of its correlation with canopy height. Along the sea-inland gradient, pioneer plant communities of upper beach were dominated by ruderals (with the lowest values of LDMC and specific leaf area - SLA), well-adapted to the harsh environmental conditions of coastal dunes. More distant from the sea, where

  7. Forcings of nutrient, oxygen, and primary production interannual variability in the southeast Atlantic Ocean

    Bachèlery, M.-L.; Illig, S.; Dadou, I.


    The recurrent occurrences of interannual warm and cold events along the coast of Africa have been intensively studied because of their striking effects on climate and fisheries. Using sensitivity experimentation based on a coupled physical/biogeochemical model, we show that the oceanic remote equatorial forcing explains more than 85% of coastal interannual nitrate and oxygen fluctuations along the Angolan and Namibian coasts up to the Benguela Upwelling System (BUS). These events, associated with poleward propagations of upwelling and downwelling Coastal Trapped Waves (CTW), are maximum in subsurface and controlled by physical advection processes. Surprisingly, an abrupt change in the CTW biogeochemical signature is observed in the BUS, associated with mixed vertical gradients due to the strong local upwelling dynamics. Coastal modifications of biogeochemical features result in significant primary production variations that may affect fisheries habitats and coastal biodiversity along the southwestern African coasts and in the BUS.

  8. Early diagnosis of primary Sjögren's syndrome: EULAR-SS task force clinical recommendations.

    Brito-Zerón, Pilar; Theander, Elke; Baldini, Chiara; Seror, Raphaèle; Retamozo, Soledad; Quartuccio, Luca; Bootsma, Hendrika; Bowman, Simon J; Dörner, Thomas; Gottenberg, Jacques-Eric; Mariette, Xavier; Bombardieri, Stefano; de Vita, Salvatore; Mandl, Thomas; Ng, Wan-Fai; Kruize, Aike A; Tzioufas, Athanasios; Vitali, Claudio; Buyon, Jill; Izmirly, Peter; Fox, Robert; Ramos-Casals, Manuel


    Sjögren's syndrome (SjS) is a systemic autoimmune disease that mainly affects the exocrine glands, leading to generalized mucosal dryness. However, primary SjS may initially present with non-sicca (systemic) manifestations. When these features appear before the onset of an overt sicca syndrome, we may talk of an underlying 'occult' SjS. The European League Against Rheumatism (EULAR) has promoted and supported an international collaborative study group (EULAR-SS Task Force) aimed at developing consensual recommendations to provide a homogeneous approach to the patient with primary SjS presenting with systemic involvement. This review summarizes the key factors that should be taken into account in the diagnostic approach in a patient with suspected SjS according to the main clinical patterns of presentation, and is especially focused on organ-specific systemic disease presentations, including a consensus set of recommendations in order to reach an early diagnosis. Close collaboration with the different specialties involved through a comprehensive multidisciplinary approach is essential in SjS patients presenting with systemic involvements.

  9. The use of plastics for belt and chain drives in primary drives of combustion engines; Die Anwendung von Kunststoffen in Riemen- und Kettentrieben bei Primaerantrieben von Verbrennungsmotoren

    Leeuwen, P. van


    It can be observed that chain drives are again used more often in engines than belt drives. There are several reasons: long durability, higher power transmission is possible, no service necessary, small construction space and low cost (?) depending on comfort aspects (noise). Polyamides, especially PA 46 have proved themselves for a long time as ideal material for slide and guide rails. The combination of dimensional stability under heat, stiffness and wear behaviour combined with the low cost must be emphasised. The development of slide and guide rails is far from being completed. Here the known specific advantages of plastics apply, i.e. the integration of functions into one component with an almost unlimited freedom of design. (orig.) [German] Grundsaetzlich ist der Trend zu beobachten, dass Kettenantriebe in modernen Motoren zu Lasten der Riemenantriebe wieder weitere Verbreitung finden. Gruende hierfuer sind: Lange Lebensdauer, hoehere Kraefteuebertragung moeglich, kein Service notwendig, geringerer Bauraum und Kosten (?) in Abhaengigkeit der Komfortaspekte (Geraeusche). Polyamide, insbesondere PA 46, haben sich seit langer Zeit bewaehrt als idealer Werkstoff fuer Spann- und Fuehrungsschienen. Besonders herauszustellen ist hier die Kombination von Waermeformbestaendigkeit, Steifigkeit und Verschleissverhalten unter Kostenaspekten. Die Entwicklung von Spann- und Fuehrungsschienen ist noch lange nicht abgeschlossen. Hier kommen die bekannten spezifischen Vorteile von Kunststoffen zur Geltung, d.h. Integration von Funktionen in einem Bauteil mit nahezu unbegrenzter Gestaltungsfreiheit. (orig.)

  10. Effect of pinning and driving force on the metastability effects in weakly pinned superconductors and the determination of spinodal line pertaining to order-disorder transition

    A D Thakur; S S Banerjee; M J Higgins; S Ramakrishnan; A K Grover


    We explore the effect of varying drive on metastability features exhibited by the vortex matter in single crystals of 2H-NbSe2 and CeRu2 with varying degree of random pinning. The metastable nature of vortex matter is reflected in the path dependence of the critical current density, which in turn is probed in a contact-less way via AC-susceptibility measurements. The sinusoidal AC magnetic field applied during AC susceptibility measurements appears to generate a driving force on the vortex matter. In a nascent pinned single crystal of 2H-NbSe2, where the peak effect (PE) pertaining to the order-disorder phenomenon is a sharp first-order-like transition, the supercooling feature below the peak temperature is easily wiped out by the reorganization caused by the AC driving force. In this paper, we elucidate the interplay between the drive and the pinning which can conspire to make the path-dependent AC-susceptibility response of different metastable vortex states appear identical. An optimal balance between the pinning and driving force is needed to view the metastability effects in typically weakly pinned specimen of low temperature superconductors. As one uses samples with larger pinning in order to differentiate the response of different metastable vortex states, one encounters a new phenomenon, viz., the second magnetization peak (SMP) anomaly prior to the PE. Supercooling/superheating can occur across both the PE and the SMP anomalies and both of these are known to display non-linear characteristics as well. Interplay between the path dependence in the critical current density and the non-linearity in the electromagnetic response determine the metastability effects seen in the first and the third harmonic response of the AC susceptibility across the temperature regions of the SMP and the PE. The limiting temperature above which metastability effects cease can be conveniently located in the third harmonic data, and the observed behavior can be rationalized within

  11. Research on Driving Force in Rural Land Capitalization%农村土地资产化的驱动力研究



    Studying the driving force in rural land capitalization is the foundation to build and perfect the mechanism of rural land capitalization. In order to solve such problems as the vacancy of the main land ownership and the limitation of land disposition, which prevent the process of rural land capitalization this paper analyzes the driving forces in rural land capitalization and their deficiencies, using the methods of empirical and normative analysis, qualitative and quantitative analysis, comparative and systems analysis, with the following conclusions; the key to building the mechanism of rural land capitalization is to enhance the driving force, improve the market environment, land management system and the government's macro-control capacity, and reduce or gradually eliminate the resistance.%研究农村土地资产化的驱动力是构建和完善农村土地资产化机制的基础.为解决土地所有权主体虚置及土地处分权受限等阻碍农村土地资产化进程的问题,采用实证分析与规范分析相结合、定性分析与定量分析相结合、比较分析法和系统分析法分析农村土地资产化的驱动力及其缺陷,得出结论是构建农村土地资产化机制的核心在于增强驱动力,完善市场环境、土地制度和政府宏观管理调控能力,减少或逐步消除土地资产化的推阻力.

  12. The effect of electric field geometry on the performance of electromembrane extraction systems: Footprints of a third driving force along with migration and diffusion

    Moazami, Hamid Reza [School of Physics and Accelerators, NSTRI, P. O. Box, 11365-8486, Tehran (Iran, Islamic Republic of); Hosseiny Davarani, Saied Saeed, E-mail: [Faculty of Chemistry, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of); Mohammadi, Jamil; Nojavan, Saeed [Faculty of Chemistry, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of); Abrari, Masoud [Laser and Plasma Research Institute, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of)


    The distribution of electric field vectors was first calculated for electromembrane extraction (EME) systems in classical and cylindrical electrode geometries. The results showed that supported liquid membrane (SLM) has a general field amplifying effect due to its lower dielectric constant in comparison with aqueous donor/acceptor solutions. The calculated norms of the electric field vector showed that a DC voltage of 50 V can create huge electric field strengths up to 64 kV m{sup −1} and 111 kV m{sup −1} in classical and cylindrical geometries respectively. In both cases, the electric field strength reached its peak value on the inner wall of the SLM. In the case of classical geometry, the field strength was a function of the polar position of the SLM whereas the field strength in cylindrical geometry was angularly uniform. In order to investigate the effect of the electrode geometry on the performance of real EME systems, the analysis was carried out in three different geometries including classical, helical and cylindrical arrangements using naproxen and sodium diclofenac as the model analytes. Despite higher field strength and extended cross sectional area, the helical and cylindrical geometries gave lower recoveries with respect to the classical EME. The observed decline of the signal was proved to be against the relations governing migration and diffusion processes, which means that a third driving force is involved in EME. The third driving force is the interaction between the radially inhomogeneous electric field and the analyte in its neutral form. - Highlights: • Electric field vectors have been calculated in EME systems. • A new driving force has been proposed in EME systems. • EME can be theoretically applied to nonionic polarizable analytes.

  13. Using geoinformatics and cultural anthropology to identify links between land change, driving forces and actors in the Okavango catchment

    Röder, Achim; Stellmes, Marion; Pröpper, Michael; Schneibel, Anne


    intensive uses, although the same processes are likely to occur in parts of the Okavango region in the future. Literature: Banwart, S. (2011). "Save our soils." Nature 474: 151-152. Bürgi, M., A. M. Hersperger, et al. (2004). "Driving forces of landscape change - current and new directions." Landscape Ecology 19: 857-868. Butchart, S. H. M., M. Walpole, et al. (2010). "Global Biodiversity: Indicators of Recent Declines." Science 328(5982): 1164-1168. Ellis, E. C. and N. Ramankutty (2008). "Putting people in the map: anthropogenic biomes of the world." Frontiers in Ecology and the Environment 6(8): 439-447. Foley, J. A., R. Defries, et al. (2005). "Global consequences of land use." Science 309(5734): 570-574. Geist, H. J. and E. F. Lambin (2002). "Proximate causes and underlying driving forces of tropical deforestation." BioScience 52(2): 143-150. Haub, C. (2012) World Population Data Sheet. World Population Hein, L., K. van Koppen, et al. (2006). "Spatial scales, stakeholders and the valuation of ecosystem services." Ecological Economics 57: 209-228. Hersperger, A. M., M.-P. Gennaio, et al. (2010). "Linking land change with driving forces and actors: four conceptual models." Ecology and Society 15(4): 1-17. Huang, C., L. S. Davis, et al. (2002). "An assessment of support vector machines for land cover classification." International Journal of Remote Sensing 23(4): 725-749. IPCC (2013). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. T. F. Stocker, G. Qin, G.-K. Plattneret al. Cambridge, Cambridge University Press. Jönsson, P. and L. Eklundh (2004). "TIMESAT - a program for analysing time-series of satellite sensor data." Computers and Geosciences 30(833-845). Kowalski, B., N. Azebaze, et al. (2013). "Mashare - The People." Biodiversity & Ecology 5: 121-128. Lal, R. (2013). "Climate-strategic agriculture and the water-soil-waste nexus." Journal of Plant

  14. Nonstationary regimes in a Duffing oscillator subject to biharmonic forcing near a primary resonance.

    Starosvetsky, Y; Manevitch, L I


    An analytical investigation of nonstationary processes in a Duffing oscillator subject to biharmonic forcing, under conditions of primary resonance, is carried out. The earlier developed methodology of limiting phase trajectories (LPTs) for studying highly nonstationary regimes, characterized by intense energy exchanges between the different degrees of freedom, is successfully applied to the system under investigation. Two distinct types of LPT trajectories are described in the first part of the study. Conditions for the recurrent transitions in time from one type of LPT to another were derived in the first part of the analysis corresponding to the undamped case. An approximation of the LPT related to the higher amplitude of oscillations was derived using nonsmooth transformations. An analysis carried out in the study has revealed the necessary and sufficient conditions for excitation of relaxation oscillations exhibited by a lightly damped system. It was also demonstrated that the mechanism of relaxations may be approximated and explained by the methodology of LPTs, characterized by strong energy exchanges between the coupled oscillators or, alternatively, a single oscillator and an external source of energy. The results of analytical approximations and numerical simulations are observed to be in quite satisfactory agreement.

  15. Study on Farmland Use Change and Driving Force in the High and Cold Areas in Northwest Yunnan——A Case Study of Ninglang Yi Autonomous County


    On the basis of overview of the study area,by analyzing the dynamic change of farmland in Ninglang County,we can find that the farmland area in this county tended to decrease from 1996 to 2008.According to the investigation data concerning land change provided by Bureau of Land and Resources in Ninglang County and socio-economic data provided by Bureau of Statistics in Ninglang County,we select 11 indices,such as total population,GDP,total output value of county and so on,coupled with SPSS statistical method,we adopt principal component analysis method to analyze driving force factors of farmland use change in the high and cold areas in Northwest Yunnan.The results show that the two factors of economic development and population growth are the dominant driving factors impacting farmland use change,and the policy factors,such as "returning farmland to forests",are also the important driving factors impacting Ninglang County.

  16. Driving force-dependent block by internal Ba(2+) on the Kir2.1 channel: Mechanistic insight into inward rectification.

    Hsieh, Chi-Pan; Kuo, Chung-Chin; Huang, Chiung-Wei


    The Kir2.1 channel is characterized by strong inward rectification; however, the mechanism of the steep voltage dependence near the equilibrium potential remains to be investigated. Here, we studied the internal Ba(2+) block of the Kir2.1 channel expressed in Xenopus oocytes. We showed that the driving force and thus the K(+) ion flux significantly influenced the apparent affinity of the block by internal Ba(2+). Kinetic analysis revealed that the binding rate shifted with the driving force and changed steeply near the equilibrium point, either in the presence or absence of the transmembrane electrical field. The unbinding rate was determined by the intrinsic affinity of the site. Mutagenesis studies revealed that the high-affinity binding site for Ba(2+) was located near T141 at the internal entrance of the selectivity filter. The steep change of the blocking affinity near the equilibrium potential may result from the flux-coupling effect in the single-file, multi-ion cytoplasmic pore.

  17. Driving Forces of Dynamic Changes in Soil Erosion in the Dahei Mountain Ecological Restoration Area of Northern China Based on GIS and RS.

    Li, Xiao; Niu, Xiang; Wang, Bing; Gao, Peng; Liu, Yu


    Dynamic change in soil erosion is an important focus of regional ecological restoration research. Here, the dynamic changes of soil erosion and its driving forces in the Dahei Mountain ecological restoration area of northern China were analyzed by LANDSAT TM remote sensing captured via geographic information system (GIS) technologies during three typical periods in 2004, 2008 and 2013. The results showed the following: (1) a decrease in intensive erosion and moderate erosion areas, as well as an increase in light erosion areas, was observed during two periods: one from 2004 to 2008 and the other from 2008 to 2013. (2) Between 2004 and 2008, the variation in the range of slight erosion was the largest (24.28%), followed by light erosion and intensive erosion; between 2008 and 2013, the variation in the range of intensive erosion area was the largest (9.89%), followed by slight erosion and moderate erosion. (3) Socioeconomic impact, accompanied by natural environmental factors, was the main driving force underlying the change in soil erosion within the ecological restoration area. In particular, the socioeconomic factors of per capita forest area and land reclamation rate, as well as the natural environmental factor of terrain slope, significantly influenced soil erosion changes within the ecological restoration area.

  18. The effect of electric field geometry on the performance of electromembrane extraction systems: footprints of a third driving force along with migration and diffusion.

    Moazami, Hamid Reza; Hosseiny Davarani, Saied Saeed; Mohammadi, Jamil; Nojavan, Saeed; Abrari, Masoud


    The distribution of electric field vectors was first calculated for electromembrane extraction (EME) systems in classical and cylindrical electrode geometries. The results showed that supported liquid membrane (SLM) has a general field amplifying effect due to its lower dielectric constant in comparison with aqueous donor/acceptor solutions. The calculated norms of the electric field vector showed that a DC voltage of 50 V can create huge electric field strengths up to 64 kV m(-1) and 111 kV m(-1) in classical and cylindrical geometries respectively. In both cases, the electric field strength reached its peak value on the inner wall of the SLM. In the case of classical geometry, the field strength was a function of the polar position of the SLM whereas the field strength in cylindrical geometry was angularly uniform. In order to investigate the effect of the electrode geometry on the performance of real EME systems, the analysis was carried out in three different geometries including classical, helical and cylindrical arrangements using naproxen and sodium diclofenac as the model analytes. Despite higher field strength and extended cross sectional area, the helical and cylindrical geometries gave lower recoveries with respect to the classical EME. The observed decline of the signal was proved to be against the relations governing migration and diffusion processes, which means that a third driving force is involved in EME. The third driving force is the interaction between the radially inhomogeneous electric field and the analyte in its neutral form.

  19. [Spatiotemporal patterns and driving forces of land use change in industrial relocation area: a case study of old industrial area in Tiexi of Shenyang, Northeast China].

    Wang, Mei-Ling; Bing, Long-Fei; Xi, Feng-Ming; Wu, Rui; Geng, Yong


    Based on the QuickBird remote sensing images and with the support of GIS, this paper analyzed the spatiotemporal characteristics of land use change and its driving forces in old industrial area of Tiexi, Shenyang City of Liaoning Province in 2000-2010. During the study period, the industrial and mining warehouse land pattern had the greatest change, evolving from the historical pattern of residential land in the south and of industrial land in the north into residential land as the dominant land use pattern. In the last decade, the residential land area increased by 9%, mainly transferred from the industrial and mining warehouse land located in the north of Jianshe Road, while the industrial and mining warehouse land area decreased by 20%. The land areas for the commercial service and for the administrative and public services were increased by 1.3% and 3.1%, respectively. The land area for construction had a greater change, with an overall change rate being 76.9%. The land use change rate in 2000-2005 was greater than that in 2005-2010. National development strategies and policies, regional development planning, administrative reform, and industrial upgrading were the main driving forces of the land use change in old industrial area of Tiexi.

  20. Driving forces and barriers to improved energy performance of buildings: an analysis of energy performance of Swedish buildings, 2000-2006

    Fuglseth, Bente Beckstroem


    The building sector is responsible for a substantial part of energy use and green house gas emissions in Europe. This report explores driving forces and barriers to improved energy performance of buildings, using the Swedish building sector as a case. The development of energy performance of buildings in Sweden from 2000 until 2006 is explored by applying a threefold understanding of energy performance of buildings: substitution from fossil fuels to renewable energy, conversion from electrical heating to thermal energy and reduction in energy demand. Three explanatory approaches are used to analyse driving forces and barriers to improved energy performance: the techno-economic approach stresses the physical aspects of infrastructure and technologies, the institutional approach emphasizes the role of institutional factors, while the regulative approach focuses on formal rules and laws. The study concludes that all factors have promoted substitution of fossil fuels with renewable energy, while they have prevented conversion from electrical heating to thermal energy and reduction in energy demand. (author). 95 refs

  1. On the Driving Forces of Magnetically Induced Martensitic Transformation in Directionally Solidified Polycrystalline Ni-Mn-In Meta-Magnetic Shape Memory Alloy with Structural Anisotropy

    Hu, Qiaodan; Zhou, Zhenni; Yang, Liang; Huang, Yujin; Li, Jun; Li, Jianguo


    The magnetic anisotropy energy (MAE) in the ferromagnetic shape memory alloys (FSMAs) provides the driving forces to obtain large magnetic field induced strain (MFIS) by rearranging the martensitic variants. However, to date, no significant MAE was observed in the new class of Ni-Mn-Z (Z = In, Sn, Sb) metamagnetic shape memory alloys (MSMAs). Here, we report a significant magnetic anisotropy in Ni48Mn35In17 Heusler alloy with a [110]A fiber texture prepared by the directional solidification. In this case, when the applied magnetic field is along the [110]A direction, a larger magnetization change is obtained compared with that of the randomly oriented samples, which increases the driving forces for the magnetically induced martensitic transformation (MIMT). In contrast, along the [110]A direction, the magnetocaloric effect (MCE) is enhanced by 60 pct, the MFIS is improved by 20 pct, and the critical field for the MFIS is reduced by 0.5 T. Such a peculiar magnetic behavior could be well explained by a proposed model on the viewpoint of the transformation of ferromagnetic austenite phase. Furthermore, considering the thermodynamics aspects, we demonstrate that two main magnetic energies of the Zeeman energy and the MAE in the MSMAs assist each other to promote the MIMT, instead of opposing each other in the FSMAs. This discovery of the strong magnetic anisotropy in highly textured polycrystals provides a feasible route to enhance the MIMT, and new insights to design and prepare the Ni-Mn-based Heusler alloys for practical applications.

  2. The Use of Magnets for Introducing Primary School Students to Some Properties of Forces through Small-Group Pedagogy

    Carruthers, Rebecca; de Berg, Kevin


    Seventeen Grade Six students were divided into small groups to study the concept of forces in the context of magnets and their properties. The researcher, a pre-service primary school teacher, encouraged the students into conversation about magnets and it was found that, without hesitation, they talked about their prior experience of magnets. The…

  3. A piezo motor based on a new principle with high output force, rigidity and integrity: The Tuna Drive

    Liu, Xiaolong; Lu, Qingyou


    We present a linear piezoelectric motor as simple as one piezoelectric scanner tube (PST) spring-clamping a central shaft at both ends with roughly equal clamping forces. The clamping points are aligned with ±X electrodes at one end and ±Y electrodes at the other end. Thus, the ±X (or ±Y) push-pull motions of the PST can cause the push-pull motions of the clamping points on the shaft (called push-pull rubbing), which reduces the total dynamic friction force at one (or the other) end of the PST. This new piezo motor advances one step by fast push-pull rubbing at one end while slowly retracting the PST followed by fast push-pull rubbing at the other end while slowly elongating the PST. Apart from the obvious advantages of simplicity, rigidity, integrity, etc., we will also show that this motor can produce a large output force, which we believe is because of the huge drop of the clamping friction force when the push-pull rubbing occurs.

  4. The Contribution of Electric Force to Sintering Ⅱ.Natures of the Applied Electric Field for Driving lonic Diffusion



    Through discussion on the acting forces of the applied electric field on the ionic system,it was shown that a periordical field with both even and odd components is to be applied.The suitable wavelengty,the extent of the field intensity and electric potential and the application of the selected field were suggested.

  5. The short range anion-H interaction is the driving force for crystal formation of ions in water.

    Alejandre, José; Chapela, Gustavo A; Bresme, Fernando; Hansen, Jean-Pierre


    The crystal formation of NaCl in water is studied by extensive molecular dynamics simulations. Ionic solutions at room temperature and various concentrations are studied using the SPC/E and TIP4P/2005 water models and seven force fields of NaCl. Most force fields of pure NaCl fail to reproduce the experimental density of the crystal, and in solution some favor dissociation at saturated conditions, while others favor crystal formation at low concentration. A new force field of NaCl is proposed, which reproduces the experimental phase diagram in the solid, liquid, and vapor regions. This force field overestimates the solubility of NaCl in water at saturation conditions when used with standard Lorentz-Berthelot combining rules for the ion-water pair potentials. It is shown that precipitation of ions is driven by the short range interaction between Cl-H pairs, a term which is generally missing in the simulation of ionic solutions. The effects of intramolecular flexibility of water on the solubility of NaCl ions are analyzed and is found to be small compared to rigid models. A flexible water model, extending the rigid SPC/E, is proposed, which incorporates Lennard-Jones interactions centered on the hydrogen atoms. This force field gives liquid-vapor coexisting densities and surface tensions in better agreement with experimental data than the rigid SPC/E model. The Cl-H, Na-O, and Cl-O pair distribution functions of the rigid and flexible models agree well with experiment. The predicted concentration dependence of the electric conductivity is in fair agreement with available experimental data.

  6. Analysis of Driving Force and Constraint Force of A 3UPU-Ⅰ Spatial Parallel Manipulator based on Force/Torque Balance Equations and CAD Variable Geometric Approach%基于力/矩平衡方程和变量几何法的3UPU-Ⅰ并联机构驱动力和约束力分析



    提出利用力/力矩平衡方程CAD变量几何法求解并联机构各分支的驱动力和约束力.以3UPU-Ⅰ并联机构为例,首先利用求解驱动力和约束力的数学方程及计算机变量几何法,在3UPU-Ⅰ并联机构的模拟基础上构造该机构的三维F/T(力/力矩)模拟机构.然后从平衡方程中推演出一个力雅克比矩Gf,当改变驱动参数时,F/T模拟机构和Gf随之变化,驱动力和约束力自动求解和动态显示.%A CAD variation geometry approach and force/torque balance equations are proposed for solving driving force and constraint force of a 3-dof 3UPU-Ⅰ spatial parallel manipulator.Taking the 3UPU-Ⅰ spatial parallel manipulator for example,by using the mathematical equation and computer variation geometry method for solving driving force and constraint force,the 3D F/T (force/torque) simulation mechanism is constructed based on simulation mechanism of the parallel manipulator.A force Jacobian matrix equation Gf is derived from the balance equations of the manipulator,when the driving dimensions of active limbs parameter is modified,the configuration of the F/ T simulation mechanisms and Gf are varied correspondingly,and the driving and constraint force are solved automatically and visualized dynamically.

  7. Improving the Drive System of Permanent Magnet Linear Synchronous Motor Based on Direct Thrust Force Control Applying Space Vector Modulation

    Mehdi Manoochehri


    Full Text Available Applying the direct thrust force control (DFC method in permanent magnet linear synchronous motor (PMLSM leads to some important problems. The most important disadvantages of applying this method are electromagnetic force and linkage flux big ripple and variable switching frequency. In this paper space vector modulation (SVM technique is applied for removing the disadvantages of classic DFC method. SVM technique makes the switching frequency constant and provides continues Voltage space compared with discrete space in classic method. Simulation results confirmed the theory. They show that combining the DFC method with SVM technique removes lots of the disadvantages of classic DFC method like big ripples and variable switching and remains the benefits of this method.

  8. The endothermic ATP hydrolysis and crossbridge attachment steps drive the increase of force with temperature in isometric and shortening muscle.

    Offer, Gerald; Ranatunga, K W


    The isometric tetanic tension of skeletal muscle increases with temperature because attached crossbridge states bearing a relatively low force convert to those bearing a higher force. It was previously proposed that the tension-generating step(s) in the crossbridge cycle was highly endothermic and was therefore itself directly targeted by changes in temperature. However, this did not explain why a rapid rise in temperature (a temperature jump) caused a much slower rate of rise of tension than a rapid length step. This led to suggestions that the step targeted by a temperature rise is not the tension-generating step but is an extra step in the attached pathway of the crossbridge cycle, perhaps located on a parallel pathway. This enigma has been a major obstacle to a full understanding of the operation of the crossbridge cycle. We have now used a previously developed mechano-kinetic model of the crossbridge cycle in frog muscle to simulate the temperature dependence of isometric tension and shortening velocity. We allowed all five steps in the cycle to be temperature-sensitive. Models with different starting combinations of enthalpy changes and activation enthalpies for the five steps were refined by downhill simplex runs and scored by their ability to fit experimental data on the temperature dependence of isometric tension and the relationship between force and shortening velocity in frog muscle. We conclude that the first tension-generating step may be weakly endothermic and that the rise of tension with temperature is largely driven by the preceding two strongly endothermic steps of ATP hydrolysis and attachment of M.ADP.Pi to actin. The refined model gave a reasonable fit to the available experimental data and after a temperature jump the overall rate of tension rise was much slower than after a length step as observed experimentally. The findings aid our understanding of the crossbridge cycle by showing that it may not be necessary to include an additional

  9. Orbital-scale nonlinear response of East Asian summer monsoon to its potential driving forces in the late Quaternary

    Yi, Liang; Shi, Zhengguo; Tan, Liangcheng; Deng, Chenglong


    We conducted a statistical study to characterize the nonlinear response of the East Asian summer monsoon (EASM) to its potential forcing factors over the last 260 ka on orbital timescales. We find that both variation in solar insolation and global ice volume were responsible for the nonlinear forcing of orbital-scale monsoonal variations, accounting for 80% of the total variance. Specifically, EASM records with dominated precession variance exhibit a more sensitive response to changes in solar insolation during intervals of enhanced monsoon strength, but are less sensitive during intervals of reduced monsoon strength. In the case of global ice volume with 100-ka variance, this difference is not one of sensitivity but rather a difference in baseline conditions, such as the relative areas of land and sea which affected the land-sea thermal gradient. We therefore suggest that EASM records with dominated precession variance recorded the signal of a shift in the location of the Inter-tropical Convergence Zone, and the associated changes in the incidence of torrential rainfall; while for proxies with dominated 100-ka variance, it recorded changes in the land-sea thermal gradient via its effects on non-torrential precipitation.

  10. Nitrogen-controlled intra- and interspecific competition between Populus purdomii and Salix rehderiana drive primary succession in the Gongga Mountain glacier retreat area.

    Song, Mengya; Yu, Lei; Jiang, Yonglei; Lei, Yanbao; Korpelainen, Helena; Niinemets, Ülo; Li, Chunyang


    In this study, intra- and interspecific competition were investigated in early successional Salix rehderiana Schneider and later-appearing Populus purdomii Rehder under non-fertilized (control) and nitrogen (N)-fertilized conditions in the Hailuogou glacier retreat area. Our aim was to discover whether N is a key factor in plant-plant competition and whether N drives the primary succession process in a glacier retreat area. We analyzed differences in responses to intra- and interspecific competition and N fertilization between P. purdomii and S. rehderiana, including parameters such as biomass accumulation, nutrient absorption, non-structural carbohydrates, photosynthetic capacity, hydrolysable amino acids and leaf ultrastructure. In the control treatments, S. rehderiana individuals subjected to interspecific competition benefited from the presence of P. purdomii plants, as indicated by higher levels of biomass accumulation, photosynthetic capacity, N absorption, amino acid contents and photosynthetic N-use efficiency. However, in the N-fertilized treatments, P. purdomii individuals exposed to interspecific competition benefited from the presence of S. rehderiana plants, as shown by a higher growth rate, enhanced carbon gain capacity, greater amino acid contents, and elevated water-use efficiency, whereas the growth of S. rehderiana was significantly reduced. Our results demonstrate that N plays a pivotal role in determining the asymmetric competition pattern among Salicaceae species during primary succession. We argue that the interactive effects of plant-plant competition and N availability are key mechanisms that drive primary succession in the Gongga Mountain glacier retreat area.

  11. Dehydrogenation Kinetics and Modeling Studies of MgH2 Enhanced by Transition Metal Oxide Catalysts Using Constant Pressure Thermodynamic Driving Forces

    Saidi Temitope Sabitu


    Full Text Available The influence of transition metal oxide catalysts (ZrO2, CeO2, Fe3O4 and Nb2O5 on the hydrogen desorption kinetics of MgH2 was investigated using constant pressure thermodynamic driving forces in which the ratio of the equilibrium plateau pressure (pm to the opposing plateau (pop was the same in all the reactions studied. The results showed Nb2O5 to be vastly superior to other catalysts for improving the thermodynamics and kinetics of MgH2. The modeling studies showed reaction at the phase boundary to be likely process controlling the reaction rates of all the systems studied.

  12. Linkage-Based Frameworks for Sustainability Assessment: Making a Case for Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA Frameworks

    Brian Veitch


    Full Text Available The main objective of this paper is to discuss different approaches, identify challenges, and to select a framework for delivering effective sustainability assessments. Sustainable development is an idealistic concept and its assessment has always been a challenge. Several approaches, methodologies and conceptual frameworks have been developed in various disciplines, ranging from engineering to business and to policy making. The paper focuses mainly on various linkage-based frameworks and demonstrates that the driving force-state-exposure-effect-action (DPSEEA framework can be used to achieve sustained health benefits and environmental protection in accordance with the principles of sustainable development, especially because of its resemblance to the environmental risk assessment and management paradigms. The comparison of linkage-based frameworks is demonstrated through an example of sustainability in a higher educational institution.

  13. Driving Force to Explore the Urban Art and Design%城市艺术设计推动力探究



    个案例的列举与分析,探讨现有城市艺术设计的成就与问题。思考部分我国现状,为城市艺术设计发展进程总结出:政府支持,商业互利,公众参与,多方合作,国际交流,五点推动力以供参考。%Based on the percentage of bill in Philadelphia of United States,the European city of culture and artistic nature,Japan's international achievements and experience of three cases cited and analysis of existing urban art and design achievements and problems.Thinking part of our current situation,urban art and design development process for the sum of government support,business benefits,public participation,multilateral cooperation,international exchange,five driving force for reference.

  14. A Study on the Electromagnet Thrust force Characteristics of Newly Proposed Hybrid Bottom-mounted Control Rod Drive Mechanism for Research Reactor

    Huh, Hyung; Cho, Yeong Garp; Choi, Myoung Hwan; Yu, Je Yong; Kim, Ji Ho; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The control rod drive mechanism (CRDM) is the part of reactor regulating system (RRS), which is located in the reactor pool top (Top-mounted) or the room below the reactor pool (Bottom-mounted). The function of the CRDM is to insert, withdraw or maintain neutron absorbing material at any required position within the reactor core, in order to the reactivity control of the core. There are so many kinds of CRDM, such as magneticjack type, hydraulic type, rack and pinion type, chain type and linear or rotary step motor and so on. As a part of a new project, we have investigated the movable coil electromagnetic drive mechanism (MCEDM) which is new scheme for the reactor control rod adopted by China Advanced Research Reactor (CARR) as shown in Fig.1. To improve a better function of the electromagnetic and magnetic characteristics, new model CRDM, which is named a hybrid bottommounted CRDM (HBCRDM), is proposed. Especially in order to achieve improved thrust force, numerical magnetic field calculations between MCEDM and HBCRDM have been carried out and the HBCRDM FEM results have been compared with the MCEDM FEM results, and FEM results are summarized in the following sections

  15. Conformational gating of the electron transfer reaction QA−⋅QB → QAQB−⋅ in bacterial reaction centers of Rhodobacter sphaeroides determined by a driving force assay

    Graige, M. S.; Feher, G.; Okamura, M. Y.


    The mechanism of the electron transfer reaction, QA−⋅QB → QAQB−⋅, was studied in isolated reaction centers from the photosynthetic bacterium Rhodobacter sphaeroides by replacing the native Q10 in the QA binding site with quinones having different redox potentials. These substitutions are expected to change the intrinsic electron transfer rate by changing the redox free energy (i.e., driving force) for electron transfer without affecting other events that may be associated with the electron transfer (e.g., protein dynamics or protonation). The electron transfer from QA−⋅ to QB was measured by three independent methods: a functional assay involving cytochrome c2 to measure the rate of QA−⋅ oxidation, optical kinetic spectroscopy to measure changes in semiquinone absorption, and kinetic near-IR spectroscopy to measure electrochromic shifts that occur in response to electron transfer. The results show that the rate of the observed electron transfer from QA−⋅ to QB does not change as the redox free energy for electron transfer is varied over a range of 150 meV. The strong temperature dependence of the observed rate rules out the possibility that the reaction is activationless. We conclude, therefore, that the independence of the observed rate on the driving force for electron transfer is due to conformational gating, that is, the rate limiting step is a conformational change required before electron transfer. This change is proposed to be the movement, controlled kinetically either by protein dynamics or intermolecular interactions, of QB by ≈5 Å as observed in the x-ray studies of Stowell et al. [Stowell, M. H. B., McPhillips, T. M., Rees, D. C., Soltis, S. M., Abresch, E. & Feher, G. (1997) Science 276, 812–816]. PMID:9751725


    ZHANG Xue-qin; GE Quan-sheng; ZHENG Jing-yun


    How land-cover has been changed by human use over the last 300 years is one of the five overarching questions guiding the Land-use/Cover Change (LUCC) Science/Research Plan. China has variety of historical docu-ments providing unique data superiority. So the characteristics of farmland area in Shandong Province during the Qing Dynasty (1644-1911) are summarized firstly: 1) the rising trend of farmland area was striking; 2) farmland area had re-markable fluctuation; 3) farmland area per capita decreased dramatically; 4) wasteland reclamation index increased rapidly. Then, the driving forces of farmland area change are analyzed. It is concluded that natural and human factors are jointly influential. Among the driving forces, human dimensions are the main factors of farn land area change,which direct the general tendency of the changes mentioned above. And the natural factors influence the stability of farmland area as well. Variation of the natural factors would act as the major contributory factor to farmland area change during years or periods of abrupt climatic changes, or during the intensive occurring periods of natural hazards.Besides, the passive aspects of human factors, such as war chaos also influenced the fluctuation of the farmland area.This research indicates that it is feasible to study the land-use/cover change by Chinese historical literatures, which has huge potential to provide a comprehensive picture of the growing dominance of human land-use and land-cover pat-terns that can be used in many global change research projects.

  17. European climate in the late twenty-first century: regional simulations with two driving global models and two forcing scenarios

    Raeisaenen, J. [Division of Atmospheric Sciences, Department of Physical Sciences, University of Helsinki, Gustaf Haellstroemin katu 2, PO Box 64, 00014, Helsinki (Finland); Rossby Centre, Swedish Meteorological and Hydrological Institute, 60176, Norrkoeping (Sweden); Hansson, U.; Ullerstig, A.; Doescher, R.; Graham, L.P.; Jones, C.; Meier, H.E.M.; Samuelsson, P.; Willen, U. [Rossby Centre, Swedish Meteorological and Hydrological Institute, 60176, Norrkoeping (Sweden)


    A basic analysis is presented for a series of regional climate change simulations that were conducted by the Swedish Rossby Centre and contribute to the PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects) project. For each of the two driving global models HadAM3H and ECHAM4/OPYC3, a 30-year control run and two 30-year scenario runs (based on the SRES A2 and B2 emission scenarios) were made with the regional model. In this way, four realizations of climate change from 1961-1990 to 2071-2100 were obtained. The simulated changes are larger for the A2 than the B2 scenario (although with few qualitative differences) and in most cases in the ECHAM4/OPYC3-driven (RE) than in the HadAM3H-driven (RH) regional simulations. In all the scenario runs, the warming in northern Europe is largest in winter or late autumn. In central and southern Europe, the warming peaks in summer when it locally reaches 10 C in the RE-A2 simulation and 6-7 C in the RH-A2 and RE-B2 simulations. The four simulations agree on a general increase in precipitation in northern Europe especially in winter and on a general decrease in precipitation in southern and central Europe in summer, but the magnitude and the geographical patterns of the change differ markedly between RH and RE. This reflects very different changes in the atmospheric circulation during the winter half-year, which also lead to quite different simulated changes in windiness. All four simulations show a large increase in the lowest minimum temperatures in northern, central and eastern Europe, most likely due to reduced snow cover. Extreme daily precipitation increases even in most of those areas where the mean annual precipitation decreases. (orig.)

  18. Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.

    Jianhui Song

    Full Text Available Molecular recognition by intrinsically disordered proteins (IDPs commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs.

  19. Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.

    Song, Jianhui; Ng, Sheung Chun; Tompa, Peter; Lee, Kevin A W; Chan, Hue Sun


    Molecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD) is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs.

  20. A Model for the Force Exerted on a Primary Cilium by an Optical Trap and the Resulting Deformation

    Ian Lofgren


    Full Text Available Cilia are slender flexible structures extending from the cell body; genetically similar to flagella. Although their existence has been long known, the mechanical and functional properties of non-motile (“primary” cilia are largely unknown. Optical traps are a non-contact method of applying a localized force to microscopic objects and an ideal tool for the study of ciliary mechanics. We present a method to measure the mechanical properties of a cilium using an analytic model of a flexible, anchored cylinder held within an optical trap. The force density is found using the discrete-dipole approximation. Utilizing Euler-Bernoulli beam theory, we then integrate this force density and numerically obtain the equilibrium deformation of the cilium in response to an optical trap. The presented results demonstrate that optical trapping can provide a great deal of information and insight about the properties and functions of the primary cilium.

  1. Intrinsic driving force of rural land integrated consolidation%农村土地综合整治的内在驱动力分析

    邹伟; 胡莉; 林庶民; 胡锋


      为充分发挥农村土地综合整治的积极作用,从理论上探究其与城乡统筹发展的关系,从历史角度对其进行定位,并进行理论升华。在对农村土地整治内涵剖析的基础上,从经济、社会、政治3个方面分析农村土地综合整治的内在驱动力,揭示了农村土地综合整治对社会经济的积极影响,进而对农村土地综合整治进行了理性思考,最后从规划管理、决策机制、产权制度、收益分配、主导主体和配套制度等方面提出相关的对策建议,该文为进一步推进农村土地综合整治提供了较好的理论支撑和实践参考。%Urban-rural integrated development is one of the important topics of today's society and economic development in China. In recent years, being a crucial means of urban-rural integrated development, rural land integrated consolidation has received unprecedented advancement, which has also functioned positively in aspects such as alleviating the contradiction between supply and demand of land, changing farmers' production and lifestyle, and so on. However, issues such as farmers' being forced to go upstairs and poverty due to going upstairs which went against farmers' will and did harm to farmers' right appeared in some places, and those issues have a negative influence on propelling consolidation activity. Some researchers and management levels expressed doubts about it, and a land-management department was once forced to suspend the approval of relevant project. Now, it is very urgent to clarify the relationship between rural land integrated consolidation and the urban-rural integrated development theoretically, discuss the inner driving force, and to implement the theory. Firstly, from the perspective of concept refreshment, this paper makes fundamental analysis of the connotation, nature, function, and significance of rural land integrated consolidation under urban-rural integrated development, proposes

  2. 基于EKF的Duffing振子正弦策动力判别算法%Identification of Sine Driving Force of Duffing Oscillator Based on Extended Kalman Filter

    芮国胜; 张洋; 张嵩; 苗俊


    以Duffing振子系统为研究对象,分析了以正弦函数为周期策动力的Duffing方程基本形式及相应的振子运动,并用扩展卡尔曼滤波(extended Kalnan filter,EKF)对Duffing振子系统进行递推滤波,实现了对Duffing振子系统的稳定估计.根据滤波过程中周期策动力随卡尔曼增益的变化,提出了一种基于卡尔曼增益判别Duffing振子系统周期策动力的方法,可以作为运用Duffing振子进行弱信号检测的依据.仿真结果表明,与经典Lyapunov指数判别法相比,该算法具有更好的判别性能.%In studying Duffing oscillator systems, a basic model using sine function as a periodic driving force and the system oscillator's movement are analyzed. Extended Kalman filter is used to process and estimate the Duffing oscillator system according to the change of the Kalman gain in the filtering process. A method using the Kalman gain to identify the periodic force is proposed, which can be used for weak signal detection with a Duffing oscillator. Simulations show performance improvement as compared with the Lypunov exponent method.

  3. Crystal structure of a trapped catalytic intermediate suggests that forced atomic proximity drives the catalysis of mIPS.

    Neelon, Kelly; Roberts, Mary F; Stec, Boguslaw


    1-L-myo-inositol-phosphate synthase (mIPS) catalyzes the first step of the unique, de novo pathway of inositol biosynthesis. However, details about the complex mIPS catalytic mechanism, which requires oxidation, enolization, intramolecular aldol cyclization, and reduction, are not fully known. To gain further insight into this mechanism, we determined the crystal structure of the wild-type mIPS from Archaeoglobus fulgidus at 1.7 Å, as well as the crystal structures of three active-site mutants. Additionally, we obtained the structure of mIPS with a trapped 5-keto-glucose-6-phosphate intermediate at 2 Å resolution by a novel (to our knowledge) process of activating the crystal at high temperature. A comparison of all of the crystal structures of mIPS described in this work suggests a novel type of catalytic mechanism that relies on the forced atomic proximity of functional groups. The lysine cluster is contained in a small volume in the active site, where random motions of these side chains are responsible for the progress of the complex multistep reaction as well as for the low rate of catalysis. The mechanism requires that functional groups of Lys-274, Lys-278, Lys-306, and Lys-367 assume differential roles in the protonation/deprotonation steps that must occur during the mIPS reaction. This mechanism is supported by the complete loss of activity of the enzyme caused by the Leu-257 mutation to Ala that releases the lysine containment.

  4. Nonequivalence of membrane voltage and ion-gradient as driving forces for the bacterial flagellar motor at low load.

    Lo, Chien-Jung; Leake, Mark C; Pilizota, Teuta; Berry, Richard M


    Many bacterial species swim using flagella. The flagellar motor couples ion flow across the cytoplasmic membrane to rotation. Ion flow is driven by both a membrane potential (V(m)) and a transmembrane concentration gradient. To investigate their relation to bacterial flagellar motor function we developed a fluorescence technique to measure V(m) in single cells, using the dye tetramethyl rhodamine methyl ester. We used a convolution model to determine the relationship between fluorescence intensity in images of cells and intracellular dye concentration, and calculated V(m) using the ratio of intracellular/extracellular dye concentration. We found V(m) = -140 +/- 14 mV in Escherichia coli at external pH 7.0 (pH(ex)), decreasing to -85 +/- 10 mV at pH(ex) 5.0. We also estimated the sodium-motive force (SMF) by combining single-cell measurements of V(m) and intracellular sodium concentration. We were able to vary the SMF between -187 +/- 15 mV and -53 +/- 15 mV by varying pH(ex) in the range 7.0-5.0 and extracellular sodium concentration in the range 1-85 mM. Rotation rates for 0.35-microm- and 1-microm-diameter beads attached to Na(+)-driven chimeric flagellar motors varied linearly with V(m). For the larger beads, the two components of the SMF were equivalent, whereas for smaller beads at a given SMF, the speed increased with sodium gradient and external sodium concentration.

  5. 南方丘陵区农业生态环境脆弱性的驱动力分析--以衡阳盆地为例%Analysis of Driving Forces of Agricultural Eco-environmental Vulnerability in the Hilly Area in Southern China:A Case Study in Hengyang Basin

    周松秀; 田亚平; 刘兰芳


    Ecological vulnerability has become a hot issue of the research on the global change and sustainable development.The hilly area of southern China is a typical ecologically fragile area.The paper takes Hengyang Basin as an example,and adopts principal component analysis to study the driving forces of the agricultural eco-environmental vulnerability.First,we define the concept of the agricultural ecology vulnerability(AEV),and analyze the contents of the AEV.Then,based on the characteristics of agricultural eco-environment,we es-tablish the AEV indexes for the Hengyang Basin in the southern China hilly areas,which include natural factors,social factors and economic factors,and take county as the evaluation unit.Principal component analysis is an important method in multivariate statistical analysis.Hence,we adopt this method to study the driving forces of the AEV in this paper,and explore the mechanism that causes the vulnerability.The results show that there are four principal driving forces affecting the vulnerability of agricultural eco-environment of this area.The natural environment and economic development background are the primary driving forces,and living standards and agricultural water facilities are the secondary forces.From the view of driving force type,the stress-type driving force is dominant,and the structure-type driving force is minor.Backward mode of production is a powerful driving force of the AEV.%生态脆弱性已成为当前全球变化与可持续发展研究的热点问题。南方丘陵区是典型的生态脆弱区,因此,首先,本文给出了农业生态环境脆弱性的概念,并分析了其脆弱性的内涵。然后,以衡阳盆地为例构建南方丘陵区农业生态环境脆弱性的评价指标体系,包括自然、社会、经济因素3个方面13个具体指标,以县域为评价单元,采用主成分分析法进行研究。最后,在主成分分析基础上,分析了南方丘陵区农业生态环境脆弱性的驱动

  6. New-type driving forces of urban agglomerations development in China%中国城市群发育的新型驱动力研究

    王婧; 方创琳


    Urban agglomeration (UA) is a new terrain unit involved in international competition and international division of labor. With the development of economic globalization and the boot of information and technology, UAs in China have developed gradually. In this process, five new-type driving forces (DF) have appeared, which are economic globalization, new-type industrialization, informatization, rapid transportation and government dominant, and studies on the five ones have important value. Based on analysis of mechanism of five new-type DF for UA and comparative analysis of some relative indexes, it is found out as follows: economic globalization drives UAs enter the international system and the higher level of UAs opening and the more industrial and technology transfers, the better UAs develop under the background of economic globalization; new-type industrialization drives UAs become manufacturing bases which injects new energies for development,and the higher level of industrialization and the better high-tech industry develops, the better UAs develop; informatization integrates all information and drives them flow at a high speed, and the higher level of informatization, the better UAs develop under the background of informatization age; transportation is the channel for materials and information exchange, and rapid transportation impels UAs to be connected closely and builds up the foundation of UAs development; new correlative policy is like a roll booster for impelling UAs development, in a correct way. Based on the above analysis, the paper suggests that further studies towards UAs development in China should focus on spatial and temporal differences of DFs and braking forces.%城市群是国家参与全球竞争和国际分工的全新地域单元,城市群发育对于推进城市化进程、增强综合国力具有显著作用,研究城市群发育驱动力具有重要价值.伴随着不断加强的全球化、信息化进程,中国城市群逐渐发育

  7. 10-15 years of GST monitoring over mountain permafrost in Switzerland: Indicators for driving forces for permafrost evolution

    Staub, Benno; Delaloye, Reynald; Hilbich, Christin; Lambiel, Christophe; Nötzli, Jeannette; Völksch, Ingo


    Ground Surface Temperatures (GST) are mainly controlled by atmospheric factors and topographical effects and represent an important standard element within the operational permafrost monitoring network PERMOS in Switzerland. Due to its shape, position and extent the Alpine arc is influenced by prevailing winds from several directions provoking a complex and highly variable pattern of precipitation in different regions of Switzerland with a general trend to a more continental climate in some inner-alpine valleys. The lower boundary for the occurrence of mountain permafrost in the Swiss Alps is located at about 2500 m asl., close to the free atmosphere where air temperatures are almost homogenous in all regions, but precipitation usually shows large regional differences regarding timing and quantity depending on the meteorological conditions. At the elevation range of mountain permafrost the ground surface remains snow-free only for about 4-5 months (between June and November) with a high temporal and spatial variability, while over the rest of the year it stays well shielded from the atmosphere (due to the high surface albedo and emissivity and low thermal conductivity of snow). Therefore, the influence of the atmosphere at this boundary layer on the ground thermal regime is well reflected by GST measurements on a very local, site-specific scale. Relative values like GST anomalies can serve as indicators describing processes of energy and heat transfer at the ground surface in a semi-quantitative way. This information is used in a signal-response analysis integrating GST with other permafrost monitoring elements that represent the permafrost response to external effects (e.g. relative changes in borehole temperatures, apparent electrical resistivities or rock glacier creep rates). To identify and quantify the dominant processes and factors controlling the response of Alpine permafrost to external forces, special consideration is devoted to the characteristics of

  8. Mr. Gove's Road to Privatisation: Forcing Primary Schools to Become Academies

    Mansfield, Melian


    Not content with the response to his offer to outstanding schools to become academies, Michael Gove's next move has been to force schools to become academies. Resistance from parents and the local community has made no difference. This article explains what happened in Haringey and how undemocratic the whole process has been.

  9. Empirical Analysis of Internal Driving Force of Medical Professionalism%医师职业精神内源性驱动力的实证探讨

    于德华; 李建刚; 许树长; 黄红; 刘薇群; 董政军; 程卢山


    以“优质护理服务工程”、产科“一贯制”工作模式与传统工作模式为基础,分析了医务人员职业精神内源性驱动力的差异.结果表明:不同工作模式下心理契约有显著差异,变革组高于试点组; “医患交流互动”因素对工作行为发生积极变化的重要性有显著的差异,变革组高于传统组;在相同工作环境下,不同自尊水平的医务人员,其职业精神的表现有显著差异,自尊水平越高,员工满意度和工作敬业度得分越高、工作倦怠得分越低,即职业精神表现越好.提出医师职业精神的内源性驱动力来自3个方面:内部组织赋予医务人员的内心体验,外部顾客(患者)赋予医务人员的内心体验,医务人员自我人格特征.%With comparing "High Quality Nursing Service Project" and "Consistent Obstetrics" with traditional working mode, the difference of internal driving force of medical professionalism is analyzed. Results indicate that the difference of psychological contract in different working modes is significant, and the score of reform group is higher than that in traditional group; the importance of the factor of "doctor-patient communication" which has caused positive changes of work behavior is significantly different in different working modes, and the score of reform group is higher than that in traditional group; in the same working mode, medical staffs having different self-esteem levels have different employee satisfaction, and the higher level of self-esteem medical staffs have, the higher their employee satisfaction. The internal driving force of medical professionalism lies in 3 aspects: inner experience from internal organization, inner feeling from external customer (patients), and self personality characteristics of medical staffs.

  10. Differential thermodynamic driving force of first- and second-generation antihistamines to determine their binding affinity for human H1 receptors.

    Hishinuma, Shigeru; Sugawara, Kenta; Uesawa, Yoshihiro; Fukui, Hiroyuki; Shoji, Masaru


    Differential binding sites for first- and second-generation antihistamines were indicated on the basis of the crystal structure of human histamine H1 receptors. In this study, we evaluated differences between the thermodynamic driving forces of first- and second-generation antihistamines for human H1 receptors and their structural determinants. The binding enthalpy and entropy of 20 antihistamines were estimated with the van't Hoff equation using their dissociation constants obtained from their displacement curves against the binding of [(3)H]mepyramine to membrane preparations of Chinese hamster ovary cells expressing human H1 receptors at various temperatures from 4°C to 37°C. Structural determinants of antihistamines for their thermodynamic binding properties were assessed by quantitative structure-activity relationship (QSAR) analyses. We found that entropy-dependent binding was more evident in second- than first-generation antihistamines, resulting in enthalpy-entropy compensation between the binding forces of first- and second-generation antihistamines. QSAR analyses indicated that enthalpy-entropy compensation was determined by the sum of degrees, maximal electrostatic potentials, water-accessible surface area and hydrogen binding acceptor count of antihistamines to regulate their affinity for receptors. In conclusion, it was revealed that entropy-dependent hydrophobic interaction was more important in the binding of second-generation antihistamines, even though the hydrophilicity of second-generation antihistamines is generally increased. Furthermore, their structural determinants responsible for enthalpy-entropy compensation were explored by QSAR analyses. These findings may contribute to understanding the fundamental mechanisms of how the affinity of ligands for their receptors is regulated.

  11. Early diagnosis of primary Sjögren's syndrome : EULAR-SS task force clinical recommendations

    Brito-Zerón, Pilar; Theander, Elke; Baldini, Chiara; Seror, Raphaèle; Retamozo, Soledad; Quartuccio, Luca; Bootsma, Hendrika; Bowman, Simon J; Dörner, Thomas; Gottenberg, Jacques-Eric; Mariette, Xavier; Bombardieri, Stefano; de Vita, Salvatore; Mandl, Thomas; Ng, Wan-Fai; Kruize, Aike A; Tzioufas, Athanasios; Vitali, Claudio; Buyon, Jill; Izmirly, Peter; Fox, Robert; Ramos-Casals, Manuel; On Behalf Of The Eular Sjögren Syndrome Task Force, [Unknown


    Sjögren's syndrome (SjS) is a systemic autoimmune disease that mainly affects the exocrine glands, leading to generalized mucosal dryness. However, primary SjS may initially present with non-sicca (systemic) manifestations. When these features appear before the onset of an overt sicca syndrome, we m

  12. Daylighting as the Driving Force of the Design Process: from the Results of a Survey to the Implementation into an Advanced Daylighting Project

    Valerio R.M. Lo Verso


    Full Text Available This paper presents a study for the transformation of an industrial area in Turin, Italy. The area hosts two buildings (one of which appointed as listed to be transformed into dwellings. A synergic approach was adopted which combined expertise from architecture, social-economics, psychology and building physics sciences. Building physics sciences lead the research team. A user-centered design was pursued, using a bottom-up approach. A specifically developed questionnaire was submitted on-line to potential users. The survey showed that ‘amount of daylight’, ‘size of rooms’, ‘tranquility of the area’ and ‘presence of a private garden’ were perceived by users to be the most positive aspects of both their present and future, ideal home. These results were then implemented into the project. The exploitation of daylight became the driving force of the transformation project. Especially for the listed building, skylights and light wells were designed to bring daylight into the cores of the buildings, which host common spaces such as libraries or study rooms. The amount of daylight was assessed through the legislative index of the average daylight factor and through a climate-based modeling approach, calculating dynamic metrics such as the spatial daylight autonomy and the Useful Daylight Illuminance. The paper critically compares and discusses these two approaches. Finally, the energy demand for lighting was also calculated to analyze how the increased exploitation of daylight may imply a reduced need for electricity for lighting.

  13. Background, driving force and constraints to build smart grids%智能电网的背景、推动力和制约

    穆钢; 肖白


    The scope of smart grids was discussed in this paper. The background, the driving forces and the constraints of smart grids were investigated. And some emerging frontier technologies of smart grids were summarized. For the new challenges of large scale renewable generation incorporating to grid, the comprehensive strategies should be adopted to multi-aspects (power generation side, grid side and load side) to overcome the side effects of grid renewable generation. Many countermeasures can be taken to achieve the well power generation at power generation side, unhindered power transmission at grid side and proper utilization at load side.%讨论智能电网的范畴,分析智能电网发展的背景、推动力和制约,概述智能电网的几个前沿领域.针对智能电网面临的“大规模可再生能源接入”新挑战,指出克服其影响应多管齐下、综合施策.分别讨论在电源侧、电网侧和负荷侧可以采取的对策,以实现电源侧发得好、电网侧送得出、负荷侧用得巧.

  14. A thermo-mechanical correlation with driving forces for hcp martensite and twin formations in the Fe–Mn–C system exhibiting multicomposition sets

    Jinichiro Nakano


    Full Text Available The thermodynamic properties of the Fe–Mn–C system were investigated by using an analytical model constructed by a CALPHAD approach. The stacking fault energy (SFE of the fcc structure with respect to the hcp phase was always constant at T0, independent of the composition and temperature when other related parameters were assumed to be constant. Experimental limits for the thermal hcp formation and the mechanical (deformation-induced hcp formation were separated by the SFE at T0. The driving force for the fcc to hcp transition, defined as a dimensionless value –dGm/(RT, was determined in the presence of Fe-rich and Mn-rich composition sets in each phase. Carbon tended to partition to the Mn-rich phase rather than to the Fe-rich phase for the compositions studied. The results obtained revealed a thermo-mechanical correlation with empirical yield strength, maximum true stress and maximum true strain. The proportionality between thermodynamics and mechanical properties is discussed.

  15. Long-term Dynamics of Cultivated Land Resources and Their Driving Forces of Guyuan City in Upper Reaches of Jinghe River

    CHEN Caocao; XIE Gaodi; ZHEN Lin; LENG Yunfa


    The land use patterns in Guyuan City, Ningxia Hui Autonomous Region of China, have changed greatlyover the years, due to population growth and farming and stock raising development. This study, using 50-year statis-tical data of cultivated land and 14-year spatial data of land use pattern, analyzed the developmental stages, the char-acter, and the spatial variance of farmland in the city, and discussed the driving forces of cultivated land changes basedon empirical and conceptual statistical models. First, the change of cultivated land area went through different stages ofrapid increase, fluctuating change, decrease and rapid decrease from 1949 to 2004, additionally, social and economicpolicies in different stages had an important impact on farmland variance. Second, from 1986 to 2000, the quantity ofcultivated land increased, but its quality decreased. Third, social and economic factors are determinant factors in culti-vated land transition. Five constructed paths explain cultivated land transition. Factors that have direct or indirect ef-fects on farmland include the economy (Xeco), the population (Xpop), agricultural output (Xagr), and scientific input (Xsci).The sequence of impact was Xeco>Xpop>Xsci>Xagr. Among all these impacts, Xeco was the major positive one, and Xpopwas the major negative one. It is urgent to take measures or adopt a policy to stop the vicious cycle in coo-environmentand agriculture production. Otherwise, negative patterns of farmland use will increase, and high-quality cultivated landwill continue to decline.

  16. A thermo-mechanical correlation with driving forces for hcp martensite and twin formations in the Fe-Mn-C system exhibiting multicomposition sets.

    Nakano, Jinichiro


    The thermodynamic properties of the Fe-Mn-C system were investigated by using an analytical model constructed by a CALPHAD approach. The stacking fault energy (SFE) of the fcc structure with respect to the hcp phase was always constant at T0, independent of the composition and temperature when other related parameters were assumed to be constant. Experimental limits for the thermal hcp formation and the mechanical (deformation-induced) hcp formation were separated by the SFE at T0. The driving force for the fcc to hcp transition, defined as a dimensionless value -dGm/(RT), was determined in the presence of Fe-rich and Mn-rich composition sets in each phase. Carbon tended to partition to the Mn-rich phase rather than to the Fe-rich phase for the compositions studied. The results obtained revealed a thermo-mechanical correlation with empirical yield strength, maximum true stress and maximum true strain. The proportionality between thermodynamics and mechanical properties is discussed.

  17. Driving forces in researchers mobility

    Gargiulo, Floriana


    Starting from the dataset of the publication corpus of the APS during the period 1955-2009, we reconstruct the individual researchers trajectories, namely the list of the consecutive affiliations for each scholar. Crossing this information with different geographic datasets we embed these trajectories in a spatial framework. Using methods from network theory and complex systems analysis we characterise these patterns in terms of topological network properties and we analyse the dependence of an academic path across different dimensions: the distance between two subsequent positions, the relative importance of the institutions (in terms of number of publications) and some socio-cultural traits. We show that distance is not always a good predictor for the next affiliation while other factors like "the previous steps" of the career of the researchers (in particular the first position) or the linguistic and historical similarity between two countries can have an important impact. Finally we show that the dataset ...

  18. Analysis on Farmland Changes and the Driving Forces in Shijiazhuang%石家庄市耕地变化及其驱动力分析

    刘巧芹; 连季婷; 宁玉萍; 郭爱请; 秦岭; 齐志国


    In order to draw up viable farmland protection measures and intensive land use standards of urban and rural settlements, farmland changes and the driving forces were analyzed by comparative analysis and principal component analysis. The results showed that: total arable land and per capita farmland showed a decreasing trend; the reducing rate of cultivated land in fast economic development year was bigger than that of in slow development time, and the counties with high levels of economic development had higher reducing rate than the counties with low levels of economic development; among the factors of farmland reduction, economic development was the fundamental driving factor, population growth was an important one, technological progress and ascension of multiple cropping index compensate for the loss of production capacity of arable land, and the national policy had an important impact on the reduction rate of farmland; protection of farmland should be enhanced from population controlled, the construction land planned scientifically and controlled strictly, and the protection of basic farmland strengthened, etc so that the relationship between human and land coordinates develop in Shijiazhuang.%为了制定切实可行的耕地保护措施和城乡居民点集约用地标准,应用对比分析和主成分分析法,分析了石家庄市耕地变化特征及其驱动力.结果表明,石家庄市耕地总面积和人均耕地面积呈现减少趋势,减少速率时间和区域差异明显,经济发展速度快的年份和经济发展水平高的县市减少速率大;经济发展是耕地减少的根本动力,人口增长是耕地减少的重要因素,科技进步和复种指数提高补偿了耕地减少的产能损失,国家政策松紧对耕地减少速率具有重要影响;应从控制人口数量、科学规划并严格控制建设用地、加强基本农田保护等方面加强耕地保护,以促进区域人地关系协调发展.

  19. 多倍化是杂草起源与演化的驱动力%Polyploidization, one of the driving forces for weed origin and evolution

    李君; 强胜


    杂草及外来植物入侵给全球经济发展及生态环境都带来了严重危害,研究其起源与演化将有助于它们的管理与控制.多倍化是植物进化的主要驱动力量,然而多倍化在杂草起源与演化中的作用还停留在种类统计以及零碎的研究案例证据上.本文综述了植物多倍体基因组结构及基因表达的研究进展以及染色体加倍后的生态学效应.多倍化促进了基因组水平与表型水平的进化,影响物种或群体生存竞争能力和繁殖扩展能力,提高物种或群体生态适应性.这一遗传过程可能促使外来种在新的生境中的成功入侵进而转变为杂草,并提出重视开展对杂草及外来入侵植物的多倍化研究的设想.%Weeds and alien invasive plants have caused tremendously ecological and socio-economic damages and loses worldwide, therefore,it is important to study origin and evolution of weeds for their effective management. Polyploidy is believed to be the main driving force of plant evolution, however, its playing the role in weeds origin and evolution is poorly understood. In this paper we review the progresses on the polyploid genome structure and gene expression and the ecological consequences of chromosome doubling. The polyploidy promotes the evolution of genomic and phenotype, affects the species survival competition, reproduction and expansion capability, and improves the ecological adaptability. Polyploidization can drive the successful invasion of invasive alien species and consequently evolution into a weed in new habitats. In addition, it is proposed that the research works on invasive alien plants may focus on polyploidization function in weed evolution and alien plant invasion.

  20. Assessing driving forces of land use and land cover change by a mixed-method approach in north-eastern Ghana, West Africa.

    Kleemann, Janina; Baysal, Gülendam; Bulley, Henry N N; Fürst, Christine


    Land use and land cover change (LULCC) is the result of complex human-environmental interactions. The high interdependencies in social-ecological systems make it difficult to identify the main drivers. However, knowledge of key drivers of LULCC, including indirect (underlying) drivers which cannot be easily determined by spatial or economic analyses, is essential for land use planning and especially important in developing countries. We used a mixed-method approach in order to detect drivers of LULCC in the Upper East Region of northern Ghana by different qualitative and quantitative methods which were compared in a confidence level analysis. Viewpoints from experts help to answer why the land use is changing, since many triggering effects, especially non-spatial and indirect drivers of LULCC, are not measurable by other methodological approaches. Geo-statistical or economic analyses add to validate the relevance of the expert-based results. First, we conducted in-depth interviews and developed a list of 34 direct and indirect drivers of LULCC. Subsequently, a group of experts was asked in a questionnaire to select the most important drivers by using a Likert scale. This information was complemented by remote sensing analysis. Finally, the driver analysis was compared to information from literature. Based on these analyses there is a very high confidence that population growth, especially in rural areas, is a major driver of LULCC. Further, current farming practice, bush fires, livestock, the road network and climate variability were the main direct drivers while the financial capital of farmers and customary norms regarding land tenure were listed as important indirect drivers with high confidence. Many of these driving forces, such as labour shortage and migration, are furthermore interdependent. Governmental laws, credits, the service by extension officers, conservational agriculture and foreign agricultural medium-scale investments are currently not driving

  1. Drive Stands

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  2. [Change of vegetation net primary productivity in Yellow River watersheds from 2001 to 2010 and its climatic driving factors analysis].

    Chen, Qiang; Chen, Yun-Hao; Wang, Meng-Jie; Jiang, Wei-Guo; Hou, Peng; Li, Ying


    Based on the MODIS-NDVI remotely sensed imagery, this paper analyzed the spatial distribution of vegetation net primary production (NPP) calculated by CASA model in Yellow River watersheds from 2001 to 2010. Associated with the temperature and precipitation data in the same period, this article respectively analyzed the change trends of vegetation NPP in six ecosystems with different spatial and temporal scales, and the relationship between NPP and climate factors. The results indicated that in terms of spatial scale, the vegetation NPP gradually reduced from northwest to southeast, the average of annual NPP was 108.53 Tg C, and the spatial distribution of vegetation NPP was highly related with the land cover types. In terms of temporal scale, the vegetation NPP gradually increased from 2001 to 2010, but this change trend had large differences in these regions. On annual level, the vegetation NPP had no significant correlation with climate factors, but precipitation and temperature had considerable impacts on the vegetation NPP on monthly level. The correlations between NPP and climate factors were different in different ecosystems, so did the time lag effect of the climate factors. The air temperature response of the NPP variation was relatively sensitive in forest ecosystem and the precipitation response was significant in grassland and wetland ecosystems. Additionally, the precipitation response of the NPP variation in grassland ecosystem had time lag effect and so did the air temperature response in desert ecosystem.

  3. Shifting grassland plant community structure drives positive interactive effects of warming and diversity on aboveground net primary productivity.

    Cowles, Jane M; Wragg, Peter D; Wright, Alexandra J; Powers, Jennifer S; Tilman, David


    Ecosystems worldwide are increasingly impacted by multiple drivers of environmental change, including climate warming and loss of biodiversity. We show, using a long-term factorial experiment, that plant diversity loss alters the effects of warming on productivity. Aboveground primary productivity was increased by both high plant diversity and warming, and, in concert, warming (≈1.5 °C average above and belowground warming over the growing season) and diversity caused a greater than additive increase in aboveground productivity. The aboveground warming effects increased over time, particularly at higher levels of diversity, perhaps because of warming-induced increases in legume and C4 bunch grass abundances, and facilitative feedbacks of these species on productivity. Moreover, higher plant diversity was associated with the amelioration of warming-induced environmental conditions. This led to cooler temperatures, decreased vapor pressure deficit, and increased surface soil moisture in higher diversity communities. Root biomass (0-30 cm) was likewise consistently greater at higher plant diversity and was greater with warming in monocultures and at intermediate diversity, but at high diversity warming had no detectable effect. This may be because warming increased the abundance of legumes, which have lower root : shoot ratios than the other types of plants. In addition, legumes increase soil nitrogen (N) supply, which could make N less limiting to other species and potentially decrease their investment in roots. The negative warming × diversity interaction on root mass led to an overall negative interactive effect of these two global change factors on the sum of above and belowground biomass, and thus likely on total plant carbon stores. In total, plant diversity increased the effect of warming on aboveground net productivity and moderated the effect on root mass. These divergent effects suggest that warming and changes in plant diversity are likely to have both

  4. Loss of TAK1 increases cell traction force in a ROS-dependent manner to drive epithelial–mesenchymal transition of cancer cells

    Lam, C R I; Tan, C; Teo, Z; Tay, C Y; Phua, T; Wu, Y L; Cai, P Q; Tan, L P; Chen, X; Zhu, P; Tan, N S


    Epithelial–mesenchymal transition (EMT) is a crucial step in tumor progression, and the TGFβ–SMAD signaling pathway as an inductor of EMT in many tumor types is well recognized. However, the role of non-canonical TGFβ–TAK1 signaling in EMT remains unclear. Herein, we show that TAK1 deficiency drives metastatic skin squamous cell carcinoma earlier into EMT that is conditional on the elevated cellular ROS level. The expression of TAK1 is consistently reduced in invasive squamous cell carcinoma biopsies. Tumors derived from TAK1-deficient cells also exhibited pronounced invasive morphology. TAK1-deficient cancer cells adopt a more mesenchymal morphology characterized by higher number of focal adhesions, increase surface expression of integrin α5β1 and active Rac1. Notably, these mutant cells exert an increased cell traction force, an early cellular response during TGFβ1-induced EMT. The mRNA level of ZEB1 and SNAIL, transcription factors associated with mesenchymal phenotype is also upregulated in TAK1-deficient cancer cells compared with control cancer cells. We further show that TAK1 modulates Rac1 and RhoA GTPases activities via a redox-dependent downregulation of RhoA by Rac1, which involves the oxidative modification of low-molecular weight protein tyrosine phosphatase. Importantly, the treatment of TAK1-deficient cancer cells with Y27632, a selective inhibitor of Rho-associated protein kinase and antioxidant N-acetylcysteine augment and hinders EMT, respectively. Our findings suggest that a dysregulated balance in the activation of TGFβ–TAK1 and TGFβ–SMAD pathways is pivotal for TGFβ1-induced EMT. Thus, TAK1 deficiency in metastatic cancer cells increases integrin:Rac-induced ROS, which negatively regulated Rho by LMW-PTP to accelerate EMT. PMID:24113182

  5. Interactions between seasonality and oceanic forcing drive the phytoplankton variability in the tropical-temperate transition zone (~ 30°S) of Eastern Australia

    Armbrecht, Linda H.; Schaeffer, Amandine; Roughan, Moninya; Armand, Leanne K.


    The East Australian Current (EAC) has been shown to be warming rapidly, which is expected to cause latitudinal shifts in phytoplankton abundance, distribution and composition along the east Australian coast. Yet a lack of phytoplankton information exists northward of 34°S. Here, we provide the first detailed taxonomic time-series survey (monthly sampling for about one annual cycle, 2011-2012) in the east Australian tropical-temperate transition zone (~ 30°S, upstream of the EAC separation point at ~ 31-32°S). All phytoplankton (categorised depending on their association with specific water-types) show a seasonal signal with abundance maxima (minima) during summer (winter). This seasonal signal is most pronounced in the seasonal/bloom category and least expressed by deep-water taxa, which prefer cold, saline and dense bottom water independent of the season. Different extents of EAC encroachment onto the continental shelf drive the cross-shelf phytoplankton composition and distribution, such that a weak EAC is associated with phytoplankton community being organised along 'depth' and 'distance from the coast' gradients with high phytoplankton abundances inshore. A strong EAC favours the occurrence of warm-water taxa offshore and an increase in diatom abundance on the mid-shelf (53% shelf width). We conclude that the phytoplankton community in the tropical-temperate transition zone of Eastern Australia is driven by an interaction of intrinsic seasonal cycles and primarily EAC-driven oceanic forcing. Our findings benefit studies located in Western Boundary Current systems worldwide, in which warming and strengthening of these currents are predicted to severely impact phytoplankton dynamics.

  6. Loss of TAK1 increases cell traction force in a ROS-dependent manner to drive epithelial-mesenchymal transition of cancer cells.

    Lam, C R I; Tan, C; Teo, Z; Tay, C Y; Phua, T; Wu, Y L; Cai, P Q; Tan, L P; Chen, X; Zhu, P; Tan, N S


    Epithelial-mesenchymal transition (EMT) is a crucial step in tumor progression, and the TGFβ-SMAD signaling pathway as an inductor of EMT in many tumor types is well recognized. However, the role of non-canonical TGFβ-TAK1 signaling in EMT remains unclear. Herein, we show that TAK1 deficiency drives metastatic skin squamous cell carcinoma earlier into EMT that is conditional on the elevated cellular ROS level. The expression of TAK1 is consistently reduced in invasive squamous cell carcinoma biopsies. Tumors derived from TAK1-deficient cells also exhibited pronounced invasive morphology. TAK1-deficient cancer cells adopt a more mesenchymal morphology characterized by higher number of focal adhesions, increase surface expression of integrin α5β1 and active Rac1. Notably, these mutant cells exert an increased cell traction force, an early cellular response during TGFβ1-induced EMT. The mRNA level of ZEB1 and SNAIL, transcription factors associated with mesenchymal phenotype is also upregulated in TAK1-deficient cancer cells compared with control cancer cells. We further show that TAK1 modulates Rac1 and RhoA GTPases activities via a redox-dependent downregulation of RhoA by Rac1, which involves the oxidative modification of low-molecular weight protein tyrosine phosphatase. Importantly, the treatment of TAK1-deficient cancer cells with Y27632, a selective inhibitor of Rho-associated protein kinase and antioxidant N-acetylcysteine augment and hinders EMT, respectively. Our findings suggest that a dysregulated balance in the activation of TGFβ-TAK1 and TGFβ-SMAD pathways is pivotal for TGFβ1-induced EMT. Thus, TAK1 deficiency in metastatic cancer cells increases integrin:Rac-induced ROS, which negatively regulated Rho by LMW-PTP to accelerate EMT.

  7. On Driving Force and Strategy of Brand Management Strategy in Universities%大学品牌经营战略源动力与策略研究

    郑哲文; 周铁军


    China’s higher education benefits much from the enhancement of economic strength and the vast demand for talent in its scale and educational strength development,which is bound to be faced with new challenges.The implementation of the university brand strategy,strengthening the brand management strategy and enhancing the strength of universities is both an imperative that work and a long-term strategy of China’s education departments and the government.The survey data analysis for the driving force for brand management building shows that it is necessary to integrate the will of all the staff and students,assess the situation and establish brand awareness,and form the brand management strategy in line with the times.The paper proposes that the university should focus on brand management strategy and issues to emphasize.%我国的高等教育规模与教育实力发展得益于我国经济实力的增强和社会对人才的大量需求,也必然面临新的挑战;实施高校品牌战略,强化品牌经营战略,提升高校实力,是一件刻不容缓的工作,是我国教育部门和政府一项长远战略;对品牌经营建设源动力调查数据分析表明汇聚全体师生员工意愿、审时度势、树立品牌意识一、制定品牌经营战略是十分必要的和符合时势的,并提出了对大学品牌经营策略和应注重的问题。

  8. 西安市户外运动市场驱动力分析%Analysis of the driving forces of Xi'an city outdoor sports market

    刘格平; 路锋辉


    In order to promote the development of Xi'an city outdoor sports market,driving force of Xi'an city outdoor sports market development is analyzed through literature review and interview method.Results show that the development of natural resources,human resources,tourism resources play the important role in the outdoor sports market development,but the outdoor sports investment is another important part;perfect the laws and policies to help the market,but should cultivate the participants of outdoor sprots; developing market organization helps the development of marketization.To cultivate compound talents,focusing on sports,is essential to promote the development of outdoor sports market.%针对西安市户外运动发展中存在的问题,分析西安市户外运动市场驱动力.研究表明,开发自然资源、人文资源、旅游资源对户外运动市场化发展具有重要作用,但是应注重户外运动本身的投入;完善法规制度,出台政策有助于市场培育,但应把握好户外运动发展参与者的培育;发展市场组织机构,有利于户外运动企业化、俱乐部模式运作,对于促进市场化发展具有重要的意义,但应把握好行业发展的关键,而不是过分追求经济效益.培育复合型人才,侧重体育,是推进户外运动市场发展的重要内容.

  9. ERS task force statement: diagnosis and treatment of primary spontaneous pneumothorax.

    Tschopp, Jean-Marie; Bintcliffe, Oliver; Astoul, Philippe; Canalis, Emilio; Driesen, Peter; Janssen, Julius; Krasnik, Marc; Maskell, Nicholas; Van Schil, Paul; Tonia, Thomy; Waller, David A; Marquette, Charles-Hugo; Cardillo, Giuseppe


    Primary spontaneous pneumothorax (PSP) affects young healthy people with a significant recurrence rate. Recent advances in treatment have been variably implemented in clinical practice. This statement reviews the latest developments and concepts to improve clinical management and stimulate further research.The European Respiratory Society's Scientific Committee established a multidisciplinary team of pulmonologists and surgeons to produce a comprehensive review of available scientific evidence.Smoking remains the main risk factor of PSP. Routine smoking cessation is advised. More prospective data are required to better define the PSP population and incidence of recurrence. In first episodes of PSP, treatment approach is driven by symptoms rather than PSP size. The role of bullae rupture as the cause of air leakage remains unclear, implying that any treatment of PSP recurrence includes pleurodesis. Talc poudrage pleurodesis by thoracoscopy is safe, provided calibrated talc is available. Video-assisted thoracic surgery is preferred to thoracotomy as a surgical approach.In first episodes of PSP, aspiration is required only in symptomatic patients. After a persistent or recurrent PSP, definitive treatment including pleurodesis is undertaken. Future randomised controlled trials comparing different strategies are required.

  10. A simple model of ultrasound propagation in a cavitating liquid. Part II: Primary Bjerknes force and bubble structures

    Louisnard, Olivier


    In a companion paper, a reduced model for propagation of acoustic waves in a cloud of inertial cavitation bubbles was proposed. The wave attenuation was calculated directly from the energy dissipated by a single bubble, the latter being estimated directly from the fully nonlinear radial dynamics. The use of this model in a mono-dimensional configuration has shown that the attenuation near the vibrating emitter was much higher than predictions obtained from linear theory, and that this strong attenuation creates a large traveling wave contribution, even for closed domain where standing waves are normally expected. In this paper, we show that, owing to the appearance of traveling waves, the primary Bjerknes force near the emitter becomes very large and tends to expel the bubbles up to a stagnation point. Two-dimensional axi-symmetric computations of the acoustic field created by a large area immersed sonotrode are also performed, and the paths of the bubbles in the resulting Bjerknes force field are sketched. C...

  11. 双库协同机制对知识发现主流发展的驱动%The Driving Force of Double Bases Cooperating Mechanism to Knowledge Discovery Main Stream

    周颖; 杨炳儒


    The paper, by a research report, summarizes emergence and definition of double bases cooperating mecha-nism, and introduces its driving force and influence to many sides of main stream of knowledge discovery from struc-tural model to algorithm , from structuring data mining to complex type data mining. The influence also expands tophilosophy field. It has been above five years from proposing it to now. Summarizing it makes us learn a thing clear-ly : its functions are not simply improvement to algorithm, are to bring forward many new structural models and tech-nology methods . It answers those urgent questions in the one paragraph of the paper to a greater extent. So we maysay: double bases cooperating mechanism has important driving force to main stream of knowledge discovery.

  12. Estímulos ao Desenvolvimento Tecnológico: Influência do Mercado Driving Forces for Technology Development: Market

    José de A. Cid


    Full Text Available Hoje em dia não se discute mais a importância da Pesquisa e Desenvolvimento para a sobrevivência e longevidade de uma Empresa. Todo tipo de indústria sente o impacto do aumento da competição e da velocidade dos avanços tecnológicos. Entretanto, os recursos estão escassos, tanto para as despesas necessárias às atividades de negócio quanto para a pesquisa, o que deixa os gerentes com a difícil tarefa de decidir onde os recursos serão aplicados. Anos atrás, quando os recursos eram (aparentemente ilimitados a força que impulsionava a pesquisa era o desafio da descoberta do novo. A complexidade do processo, os intricados métodos de análise, a quebra de barreiras do conhecimento, alimentavam as mentes dos cientistas. Depois da pesquisa, os profissionais de marketing deveriam encontrar mercados para os novos produtos. Atualmente a pesquisa de mercado, as ferramentas de análise de negócio e outros aspectos outrora desconhecidos dos cientistas dominam as mesas dos gerentes. Este artigo descreve três diferentes abordagens na distribuição de recursos para pesquisa e resume alguns dos princípios que ajudam as empresas a funcionar melhor.Nowadays the importance of Research and Development to a Company survival and longevity is well known. Virtually every industry feels the impact of increased competition and the fast pace of technology change. However, resources are getting scarce, both for doing business and research as well, leaving managers with the tough job of selecting which project will get funding. Years ago, when money was (seemingly unlimited the driving force to research was the challenge of inventing something new. The process complexity, the intricate analysis methods, the breaking of new frontiers were the food for the scientists inquiring minds. Then marketing professionals had to work to find or create market. Now market research, business analysis tools and other aspects once unknown to scientists rule. This article

  13. Study on the Characteristics and Driving Forces of Changes of the Urban Land-Use Structure in Wuhan in 1990s%20世纪90年代武汉城市土地利用结构变动特点及动力分析

    刘耀彬; 宋学锋


    On the basis of the information entropy and equilibrium degree of urban land-use spatial structure, the paper analyzes the characteristics and rules of urban land-use spatial structure changes in Wuhan in 1990s, in which the types of land-use are shrinking and urban land-use changes are disequilibria. With PCA and GRA employed, the driving forces have also been analyzed. The driving force of dty welfare and social structure, the towing force of city industrial structure transition, and the pressing force of city construction and reconstruction are main momentum factors. Moreover, the latter forces are more significant.

  14. Longitudinal force estimation for motorized wheels driving electric vehicle based on improved closed-loop subspace identification%基于改进闭环子空间辨识的电动轮汽车纵向力估计

    徐兴; 陈特; 陈龙; 王吴杰


    In order to realize the control and coordinated allocation of tire longitudinal force for motorized wheels driving electric vehicle,a longitudinal force estimation method was proposed based on improved closed-loop subspace identification.The characteristics of electric drive system of motorized wheels driving vehicle was analyzed to propose a longitudinal force estimation model.The road simulation test on chassis dynamometer was carried out, and the experimental data were collected. The subspace identification algorithm N4SID was deviated when model input and noise were correlated.To solve the problem,an improved closed-loop subspace identification method was investigated.The results show that compared with N4SID identification method,the improved closed-loop subspace identification method has better anti-interference ability with higher longitudinal force estimation accuracy and better real-time tracking capability,which can meet the requirements of driving force model predictive control based on data driving.%为实现电动轮汽车轮胎纵向力的控制与协调分配,提出了基于改进闭环子空间辨识的电动轮汽车纵向力估计方法。分析了电动轮汽车电驱动系统特性,在此基础上提出了用于辨识的纵向力估计模型。进行底盘测功机道路模拟试验并采集数据。模型输入与噪声相关时,子空间 N4SID (nu-merical algorithm for subspace identification)辨识算法是有偏的,针对这一问题,研究了一种改进闭环子空间辨识算法。结果表明:对比子空间 N4SID 辨识算法,改进闭环子空间辨识算法辨识出的模型具有更好的抗干扰性,纵向力估计精度更高,实时跟踪效果更好,满足基于数据驱动的驱动力模型预测控制的需求。

  15. Vegetation dynamics and its driving forces from climate change and human activities in the Three-River Source Region, China from 1982 to 2012

    Zhang, Ying; Zhang, Chaobin; Wang, Zhaoqi; Chen, Yizhao; Gang, Chengcheng [School of Life Science, Nanjing University, Xianlin Road 163, Qixia District, Nanjing, 210046 (China); An, Ru [School of Earth Science and Engineering, Hohai University, Xikang Road 129, Nanjing, 210098 (China); Li, Jianlong, E-mail: [School of Life Science, Nanjing University, Xianlin Road 163, Qixia District, Nanjing, 210046 (China)


    The Three-River Source Region (TRSR), a region with key importance to the ecological security of China, has undergone climate changes and a shift in human activities driven by a series of ecological restoration projects in recent decades. To reveal the spatiotemporal dynamics of vegetation dynamics and calculate the contributions of driving factors in the TRSR across different periods from 1982 to 2012, net primary productivity (NPP) estimated using the Carnegie–Ames–Stanford approach model was used to assess the status of vegetation. The actual effects of different climatic variation trends on interannual variation in NPP were analyzed. Furthermore, the relationships of NPP with different climate factors and human activities were analyzed quantitatively. Results showed the following: from 1982 to 2012, the average NPP in the study area was 187.37 g cm{sup −2} yr{sup −1}. The average NPP exhibited a fluctuation but presented a generally increasing trend over the 31-year study period, with an increase rate of 1.31 g cm{sup −2} yr{sup −2}. During the entire study period, the average contributions of temperature, precipitation, and solar radiation to NPP interannual variation over the entire region were 0.58, 0.73, and 0.09 g cm{sup −2} yr{sup −2}, respectively. Radiation was the climate factor with the greatest influence on NPP interannual variation. The factor that restricted NPP increase changed from temperature and radiation to precipitation. The average contributions of climate change and human activities to NPP interannual variation were 1.40 g cm{sup −2} yr{sup −2} and − 0.08 g cm{sup −2} yr{sup −2}, respectively. From 1982 to 2000, the general climate conditions were favorable to vegetation recovery, whereas human activities had a weaker negative impact on vegetation growth. From 2001 to 2012, climate conditions began to have a negative impact on vegetation growth, whereas human activities made a favorable impact on vegetation

  16. Drugged Driving

    ... Parents & Educators Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu ... misuse of prescription drugs can make driving a car unsafe—just like driving after drinking alcohol. Drugged ...

  17. Stimulation of primary osteoblasts with ATP induces transient vinculin clustering at sites of high intracellular traction force.

    Tan, Toh Weng; Pfau, Bastian; Jones, David; Meyer, Thomas


    Adenosine 5'-triphosphate (ATP), released in response to mechanical and inflammatory stimuli, induces the dynamic and asynchronous protrusion and subsequent retraction of local membrane structures in osteoblasts. The molecular mechanisms involved in the ligand-stimulated herniation of the plasma membrane are largely unknown, which prompted us to investigate whether the focal-adhesion protein vinculin is engaged in the cytoskeletal alterations that underlie the ATP-induced membrane blebbing. Using time-lapse fluorescence microscopy of primary bovine osteoblast-like cells expressing green fluorescent protein-tagged vinculin, we found that stimulation of cells with 100 μM ATP resulted in the transient and rapid clustering of recombinant vinculin in the cell periphery, starting approximately 100 s after addition of the nucleotide. The ephemeral nature of the vinculin clusters was made evident by the brevity of their mean assembly and disassembly times (66.7 ± 13.3 s and 99.0 ± 6.6 s, respectively). Traction force vector maps demonstrated that the vinculin-rich clusters were localized predominantly at sites of high traction force. Intracellular calcium measurements showed that the ligand-induced increase in [Ca(2+)]i clearly preceded the clustering of vinculin, since [Ca(2+)]i levels returned to normal within 30 s of exposure to ATP, indicating that intracellular calcium transients trigger a cascade of signalling events that ultimately result in the incorporation of vinculin into membrane-associated focal aggregates.

  18. Electric drives

    Boldea, Ion


    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  19. The Investigation of Driving Forces of Constructing Japan and India Security System%日印安保体系构建的动力考察

    李家成; 李昂


    Recently,the construction of Japan and India security system becomes the new norm of the coop-eration between Japan and India.Six driving forces are boosting the development of Japan and India security system:the assertive rise of China,the enticing of the United States,the rapid rise of India,the strategic ambitions of India to leverage from Japan,Japan's stiring up troubles in the Sino-Indian border dispute,the jointly guarding of Indo-Pacific maritime security by Japan and India.The new norm may help Japan and India achieve world power ambitions and America cast “Asia-Pacific rebalancing”strategy,but it will have a significant adverse impact on the China's overall national security and reshape the geopolitical situation in the Indian-Pacific region.To differentiate Japan and India security system,China should perform the two-hand strategy with striking and hooking in for India,on the one hand,reinforce and broaden the cooperation between China and India,in order to differentiate Japan and India security system;on the other hand,push the construction of China-Pakistan Economic Corridor,in order to restrict India and enhance China's strate-gic position.%近年来,日印安保体系的构建成为日印安全合作的新常态。本文总结了日印安保体系发展的六大动力,即中国的崛起促使日印积极接近、美国鼓励日印合作更上层楼、印度的崛起促使日本拉拢印度、印度的战略雄心促使印度借力日本、日本在中印边界争端上煽风点火、日印共同“护卫”印太海上安全。这一新常态虽有助于日印实现世界大国的雄心和美国施展“亚太再平衡”战略,但却会重塑印太地区的地缘政治局势,对中国总体国家安全产生重大不利影响。中国应当对印度施行打拉结合的两手策略,一方面夯实并拓宽中印合作,以分化日印安保体系;另一方面力推中巴经济走廊建设,以牵制印度并增强中国的战略地位。

  20. Characterization of systemic disease in primary Sjogren's syndrome : EULAR-SS Task Force recommendations for articular, cutaneous, pulmonary and renal involvements

    Ramos-Casals, Manuel; Brito-Zeron, Pilar; Seror, Raphaele; Bootsma, Hendrika; Bowman, Simon J.; Doerner, Thomas; Gottenberg, Jacques-Eric; Mariette, Xavier; Theander, Elke; Bombardieri, Stefano; De Vita, Salvatore; Mandl, Thomas; Ng, Wan-Fai; Kruize, Aike; Tzioufas, Athanasios; Vitali, Claudio


    Objective. To reach a European consensus on the definition and characterization of the main organspecific extraglandular manifestations in primary SS. Methods. The EULAR-SS Task Force Group steering committee agreed to approach SS-related systemic involvement according to the EULAR SS Disease Activi

  1. Mirror illusion reduces motor cortical inhibition in the ipsilateral primary motor cortex during forceful unilateral muscle contractions

    Zult, Tjerk; Goodall, Stuart; Thomas, Kevin; Hortobagyi, Tibor; Howatson, Glyn


    Forceful, unilateral contractions modulate corticomotor paths targeting the resting, contralateral hand. However, it is unknown whether mirror-viewing of a slowly moving but forcefully contracting hand would additionally affect these paths. Here we examined corticospinal excitability and

  2. [Driving forces of carbon emission from energy consumption in China old industrial cities: a case study of Shenyang City, Northeast China].

    Ren, Wan-Xia; Geng, Yong; Xue, Bing


    To quantitatively analyze the effects of anthropogenic factors on regional environmental quality is a hot topic in the field of sustainable development research. Taking the typical old industrial city Shenyang in Northeast China as a case, and by using the IPCC method for calculating carbon emission from energy consumption, this paper estimated the carbon emission from energy consumption in the city in 1978-2009, and a time series analysis on the anthropogenic factors driving this carbon emission was made by the STIRPAT model based upon Kaya equation and ridge regression. In 1978-2009, the carbon emission in the city had a slow increase first, slow decrease then, and a rapid increase thereafter. The total carbon emission in 2009 was 4.6 times of that in 1978. Population growth was the main factor driving the growth of the emission, and there existed an equal-proportional variation between the population growth and the carbon emission growth. Urbanization was another main driving factor followed by population growth, and the per capita GDP was positively correlated with the carbon emission. Kuznets curve did not exist for the relationship between economic development and carbon emission in Shenyang. Energy source intensity reduction (representing technology improvement) was the main factor driving the reduction of the total carbon emission.

  3. 知识管理内部驱动力与知识管理动态能力关系研究%Study on relation between knowledge management internal driving force and knowledge management dynamic apability

    杨俊祥; 和金生


    知识经济时代,知识管理无疑是打造和增强企业技术创新能力、提高企业技术创新绩效的有效工具.知识管理是一个动态发展的过程,知识管理的成功离不开来自于企业内部多方面力量的推动.本文基于对知识管理内部驱动力以及知识管理的动态能力组成要素的研究分析,构建了知识管理内部驱动力各构成要素与知识管理动态能力各构成要素之间的作用关系模型,并做了实证验证,为我国企业有效实施知识管理提供了有益的理论建议和策略指导.%In the era of knowledge economy, it is undoubted that knowledge management is an effective tool for enterprises to create and enhance ability of technology innovation, and to improve the technology innovation performance. As a dynamic process, successful knowledge management depends on enterprise knowledge management internal driving forces. Based on study on the knowledge management internal driving force and knowledge management dynamic ability, this article constructs an interaction model between knowledge management internal driving forces and knowledge management dynamic ability, and conducts empirical testing, the study conclusion will provide a valuable theory suggestion and practice guidance for Chinese enterprises to carry out knowledge management.

  4. Pile Driving


    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  5. Spatial organization of cellulose microfibrils and matrix polysaccharides in primary plant cell walls as imaged by multichannel atomic force microscopy.

    Zhang, Tian; Zheng, Yunzhen; Cosgrove, Daniel J


    We used atomic force microscopy (AFM), complemented with electron microscopy, to characterize the nanoscale and mesoscale structure of the outer (periclinal) cell wall of onion scale epidermis - a model system for relating wall structure to cell wall mechanics. The epidermal wall contains ~100 lamellae, each ~40 nm thick, containing 3.5-nm wide cellulose microfibrils oriented in a common direction within a lamella but varying by ~30 to 90° between adjacent lamellae. The wall thus has a crossed polylamellate, not helicoidal, wall structure. Montages of high-resolution AFM images of the newly deposited wall surface showed that single microfibrils merge into and out of short regions of microfibril bundles, thereby forming a reticulated network. Microfibril direction within a lamella did not change gradually or abruptly across the whole face of the cell, indicating continuity of the lamella across the outer wall. A layer of pectin at the wall surface obscured the underlying cellulose microfibrils when imaged by FESEM, but not by AFM. The AFM thus preferentially detects cellulose microfibrils by probing through the soft matrix in these hydrated walls. AFM-based nanomechanical maps revealed significant heterogeneity in cell wall stiffness and adhesiveness at the nm scale. By color coding and merging these maps, the spatial distribution of soft and rigid matrix polymers could be visualized in the context of the stiffer microfibrils. Without chemical extraction and dehydration, our results provide multiscale structural details of the primary cell wall in its near-native state, with implications for microfibrils motions in different lamellae during uniaxial and biaxial extensions. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  6. Driving forces behind the increasing cardiovascular treatment intensity.A dynamic epidemiologic model of trends in Danish cardiovascular drug utilization.

    Kildemoes, Helle Wallach; Andersen, Morten

    -state (untreated, treated, dead) semi-Markov model to analyse the dynamics of drug use. Transitions were from untreated to treated (incidence), the reverse (discontinuation), and from either untreated or treated to dead. Stratified by sex and age categories, prevalence trends of "growth driving" drug categories...... were analysed, exploring trends in incidence- mortality- and discontinuation rates. Trends in prevalence proportions were estimated from logistic regression. Incidence-, discontinuation and mortality rates from Poisson regression. Results: The total cardiovascular treatment intensity increased from 285...

  7. Physical and Socioeconomic Driving Forces of Land-Use and Land-Cover Changes: A Case Study of Wuhan City, China

    Xiangmei Li


    Full Text Available To investigate precise nexus between land-use and land-cover changes (LUCC and driving factors for rational urban management, we used remotely sensed images to map land use and land cover (LULC from 1990 to 2010 for four time periods using Wuhan city, China, as a case study. Partial least squares (PLS method was applied to analyze the relationships between LUCC and the driving factors, mainly focusing on three types of LULC, that is, arable land, built-up area, and water area. The results were as follows: (1 during the past two decades, the land-use pattern in Wuhan city showed dramatic change. Arable land is made up of the largest part of the total area. The increased built-up land came mainly from the conversion of arable land for the purpose of economic development. (2 Based on the Variable Importance in Projection (VIP, the joint effects of socioeconomic and physical factors on LUCC were dominant, though annual temperature, especially annual precipitation, proved to be less significant to LUCC. Population, tertiary industry proportion, and gross output value of agriculture were the most significant factors for three major types of LULC. This study could help us better understand the driving mechanism of urban LUCC and important implications for urban management.

  8. Electric-Drive Vehicles

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)


    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  9. Mirror illusion reduces motor cortical inhibition in the ipsilateral primary motor cortex during forceful unilateral muscle contractions

    Zult, Tjerk; Goodall, Stuart; Thomas, Kevin; Hortobagyi, Tibor; Howatson, Glyn


    Forceful, unilateral contractions modulate corticomotor paths targeting the resting, contralateral hand. However, it is unknown whether mirror-viewing of a slowly moving but forcefully contracting hand would additionally affect these paths. Here we examined corticospinal excitability and short-inter

  10. A new force emerges from the dark side: evidence is growing that an intrinsic property of the universe is helping to drive its expansion

    Cookson, C


    "Astronomical surveys over the past five years have forced cosmologists to conclude that ordinary matter - in the form of familiar stars, planets and interstellar dust or more exotic objects, such as quasars and neutron stars - makes up only 4 per cent of the universe" (1 page).

  11. [Driving force analysis of land use change in the developed area based on Probit regression model: A case study of Nanjing City, China].

    Liu, Kang; Li, Yue-e; Wu, Qun; Shen, Jian-fen


    Based on the remote sensing image in 1996, 2002 and 2010, with the help of RS and GIS technology, and using the Probit regression model, this paper analyzed the characteristics of land use change in Nanjing City from 1996 to 2010, and the driving factors of land use change. The results showed that the cultivated land and woodland decreased, constructive land, garden plot and grassland continued to increase, and the comprehensive land use change rate was rising since 1996. The results of regression model for cultivated land and woodland change indicated that the change of cultivated land in the years 1996-2002 was mainly affected by the factors of "distance to the nearest rural settlement" and "farmers' population density". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "distance to the rural settlement" and "distance to the nearest road". The change of woodland in the years 1996-2002 was mainly affected by the factors of "the elevation" and "distance to the rural settlement". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "population density" and "distance to the nearest road". By comparison, the early driving factors of land use change were mainly natural factors, but in recent years, they were mainly social, economic and demographic factors.

  12. Distracted Driving

    ... What's this? Submit What's this? Submit Button Distracted Driving Recommend on Facebook Tweet Share Compartir Each day in the United States, over 8 people are killed and 1,161 injured in crashes ...



    China is promoting environmentally friendly cars to save energy and protect the environment While people enjoy the pleasure and convenience of driving, they are also creating and breathing more and more toxic

  14. Measurement of the axial force during primary peristalsis in the oesophagus using a novel electrical impedance technology.

    Gravesen, F H; McMahon, B P; Drewes, A M; Gregersen, H


    The oesophagus serves to transport food and fluid from the pharynx to the stomach. Oesophageal function is usually evaluated by means of manometry which is a proxy of the force in the radial direction. However, force measurements in the axial direction will provide a better measure of oesophageal transport function. The aim of this study was to develop a probe based on electrical impedance measurements to quantify the axial force generated by oesophageal contractions, i.e. probe elongation was associated with the axial force. Calibration with weights up to 200 g was done. The dispersion, creep, temperature and bending dependence were studied at the bench. Subsequently, the probe was tested in vivo in a healthy human volunteer. The probe showed good reproducibility and the dispersion was <0.04. Some dependence on temperature, creep and bending was found. Interpolation of the calibration curves made it possible to compensate for temperature fluctuations. The maximum deviation was 6.1 +/- 3.7% at loads of 50 g. The influence of creep showed a maximum net creep of 6.1 g after 8 s. The swallowed bolus size correlated with the axial force measurements (P = 0.038) but not with manometric measurements. In conclusion, the new technique measures axial force in the oesophagus and may in the future provide valuable information about oesophageal function.

  15. 我国现阶段土地利用变化驱动力的宏观分析%Macro-analysis on the driving forces of the land-use change in China

    李平; 李秀彬; 刘学军


    Land-use is one complex system, which is affected by many factors, including both socio-economic elements and natural resources and environment. This paper firstly established a framework for macro-analysis on the driving forces of land-use change in China, in which economic welfare, environmental welfare, the need for food security and the advancement of science and technology are the main forces contributing to the land-use changes. Then the paper analyzed the basic contradictions in the land-use change in recent years on the basis of current situation of land-use and economic development in China. In the third section, according to the analytical framework established firstly and the basic contradictions in the land-use change, and on the basis of the land-use data and other related socio economic documents in recent years, this paper analyzed and computed the indexes of the driving forces of the land-use change and represented their spatial distribution in China. By the distribution of these driving forces, the whole China can be seen as three distinct sub-areas: Tibet-southwest sub-area, central-northwest sub-area and east sub-area, each of which takes on different features in respect of the driving forces of land-use changes. As indicated in this paper, the economic welfare is the fundamental impetus to the land-use changes, and the environmental welfare and the need for food security are also important factors in China. The future land-use change is ultimately decided by the performance of these factors and their interactions.%土地利用的基本竞争模型是土地利用类型变化驱动力分析的理论基础。把握土地利用个体目标和社会目标的关系,尤其是它们之间的矛盾及其地区差异,是进行土地利用变化驱动力宏观分析的有效途径。工业化城市化与粮食安全之间的矛盾、农业发展与生态环境保护之间的矛盾是现阶段我国土地利用变化的基本矛盾。土地利用变化

  16. Aquareovirus NS80 recruits viral proteins to its inclusions, and its C-terminal domain is the primary driving force for viral inclusion formation.

    Shao, Ling; Guo, Hong; Yan, Li-Ming; Liu, Huan; Fang, Qin


    Cytoplasmic inclusion bodies formed in reovirus-infected cells are the sites of viral replication and assembly. Previous studies have suggested that the NS80 protein of aquareovirus may be involved in the formation of viral inclusion bodies. However, it remains unknown whether other viral proteins are involved in the process, and what regions of NS80 may act coordinately in mediating inclusion formation. Here, we observed that globular cytoplasmic inclusions were formed in virus-infected cells and viral proteins NS80 and NS38 colocalized in the inclusions. During transfection, singly expressed NS80 could form cytoplasmic inclusions and recruit NS38 and GFP-tagged VP4 to these structures. Further treatment of cells with nocodazole, a microtubule inhibitor, did not disrupt the inclusion, suggesting that inclusion formation does not rely on microtubule network. Besides, we identified that the region 530-742 of NS80 was likely the minimal region required for inclusion formation, and the C-tail, coiled-coil region as well as the conserved linker region were essential for inclusion phenotype. Moreover, with series deletions from the N-terminus, a stepwise conversion occurred from large condensed cytoplasmic to small nuclear inclusions, then to a diffused intracellular distribution. Notablely, we found that the nuclear inclusions, formed by NS80 truncations (471 to 513-742), colocalized with cellular protein β-catenin. These data indicated that NS80 could be a major mediator in recruiting NS38 and VP4 into inclusion structures, and the C-terminus of NS80 is responsible for inclusion formation.

  17. 鄱阳湖退化芦苇湿地驱动因子分析%Analysis on the driving forces of the degraded Phragmites australis wetlands in Poyang Lake

    周莉荫; 李勇; 任琼


    以鄱阳湖退化芦苇湿地为研究对象,综合考虑自然和人为因素,探求芦苇湿地退化的驱动力. 呼吁加强湿地植物资源管理及有效利用,保护人类赖以生存与发展的湿地资源.%In this paper, degraded Phragmites australis wetland in Poyang Lake was took as study object, natural and human factors were comprehensively considered to explore the driving force of the degradation of Ph. australis wetland. It was calling for strengthening the management and effective utilization of wetland plant resources and protecting the wetland resources for human survival and development.

  18. 制造企业服务化--驱动力、模式、路径和绩效研究综述%A Review on Driving Forces, Modes, Paths and Performance of Servitization in Manufacturing Enterprises

    高文军; 陈静; 陈菊红


    Servitization has become a hotspot of scholars at home and abroad. It reviews driving forces, modes, paths and performance of servitization in manufacturing enterprises on the base of summarizing its concept from the views of conversion process and phenomenon. It also proposes the future research framework and content in accordance with the existing deficiencies.%制造企业服务化已成为国内外学者研究的热点问题。在从转化过程和现象两个视角对制造企业服务化概念进行概述的基础上,综述了制造企业服务化的驱动力、模式、路径和绩效;基于已有研究的不足,给出了未来进一步研究的框架和内容。

  19. A contrast of two typical LUCC processes and their driving forces in oases of arid areas: A case study of Sangong River Watershed at the northern foot of Tianshan Mountains

    TANG FaShu; CHEN Xi; LUO GePing; LIN Qing; LIU HaiLong


    Aerial photographs taken in 1978 and 1987, Landsat TM images in 1998 as well as soil, hydrology and socio-economic data for the oases in Sangong River Watershed were processed by Remote Sensing (RS) and Geographic Information System (GIS). There are two typical agricultural land uses in oases,Farm-based Land Use with large-scale intensified agricultural activities (FLU) and Household Responsibility-based Land Use with small-scale activities (HRLU). The Index Model of Land Use/Land Cover Change (LUCC), Weighted Index Sum (WIS) and logistic stepwise regression model were established to contrast the two typical LUCC processes and their driving forces. The land use patterns were dominated by cropland and grassland for the entire region, and cropland, residential and industrial land were increasing stably. In the HRLU areas, woodland and grassland declined dramatically, but in the FLU areas, grassland decreased only by 12.0%, whereas woodland increased by 13.7%. LUCC was stronger in the earlier stage (1978-1987) than in the later stage (1987-1998) for the entire region. LUCC was more intense in the HRLU areas than in the FLU areas during the entire period (1978-1998). Policy was a key factor in the land use change, and water resources were a precondition in land use. Under the control of policy and water resources,the main human driving factors included population and economy, and the main natural restrictions were soil fertility and groundwater depth. Human driving factors controlled the land change in the HRLU areas, but natural restriction factors dominated in the FLU areas. In the mean time,intensification of LUCC in the region had some spatiotemporal implications with a fluctuation of impact factors.

  20. 1980-2012年村域居民点演变特征及其驱动力分析%Evolution characteristics and its driving force of rural residential land at village level during 1980-2012

    冯应斌; 杨庆媛


    Appraisal. Based on rural residential land evolution process at spatial and time dimensions and its characteristics in Guni village of Chongqing in resent 30 years since 1980, we analyzed evolution characteristics of rural residential land scale, space form, structure system and landscape pattern at village level, and summed up general rule of rural residential land evolution in space and time dimensions. The results showed that rural residential land area in Guni village was 22.79 hm2in 1980, and increased to 33.47 hm2in 2012. The average annual growth reached 1.21%. Rural residential land patch had been in a central tendency at time dimension, and expansion rate of rural residential land experienced a process from pure extension to coexistence of expansion and tightening. Rural residential land patch was in an irregular shape, which was departed from circular and square at spatial and time dimensions. The spatial structure of rural residential land presented an evolution tendency from relatively centralized to comparatively decentralized, while spatial structure system of main settlements had an acute evolution with unreasonable grade. The landscape diversity of rural residential land patch and its uniform distribution degree had a further improvement at village level, but the landscape heterogeneity had been further stood out at group level. Leading factors (total population, quantity of labor force and peasant household) could promote the expansion of rural residential land scale. However, its influence had a downward trend with time scale. Economic development level factors such as average income were inducement factors, and its driving force had further strengthened with time. Locations along the highway were one of the leading driving forces of newly-added rural residential land expansion, and the expansion of rural residential land since 2005 had been the result of new rural reconstruction policy-driven. Based on driving force model of rural residential land

  1. Death Drive

    Stühler, Rebekka Hellstrøm


    The aim of this project is to investigate why the Freudian term Death Drive is not acknowledged in modern psychological therapy. On basis of psychoanalytical theory and through a literary analysis, the project will present a discussion of the significance and presence of the term within these practises.

  2. Revolutionizing Mental Health Care Delivery in the United States Air Force By Shifting the Access Point to Primary Care


    health stigma is highly influenced by cultural and societal beliefs. More specifically, men and racial /ethnic minorities have generally higher...Air Force Medical Services (AFMS) Clinical Quality Management Program Evaluation, AFMS Gap Analysis. McLean, VA: Booz Allen Hamilton Inc., 2015...Nathaniel G. Wage , Anton P. Sirotin, Russell A. McCann, and Melinda J. Metzger-Abamukong. “Development and Initial Testing of a Measure of Public and Self

  3. Driving Mechanism Study on Rural Labour Force's Transference Under the City and Countryside Overall Plan%城乡统筹视角下农村劳动力转移驱动机理研究

    石永明; 邱道持; 骆东奇


    农村劳动力转移对促进社会主义新农村建设、解决“三农”问题意义重大.本文以重庆市璧山县为例,在对2个街办3个乡镇150余农户抽样调查基础上分析了该地区农村劳动力转移的经济学、土地流转、心理学和社会学方面的驱动机理,并提出加快农村劳动力转移需完善保障机制、发展现代农业、加快城镇建设等一系列建议.%Rural Labour Force's Transference has big sense in promoting the socialistic new rural construction and resolving the "countryside-agriculture-farmer" problems. On the census data from more than 150 rural families (mainly is egress work) and more than 150 peasant laborer being out of 3 towns and 2 sub-district offices in the Chongqing Municipality's Bishan County, this paper has analyzed its economic, psychological and land circulation and sociological driving mechanism, and proposed to consummate the safeguard mechanism, to develop modern agriculture, to develop the town construction and so on a series of suggestions for speeding up the Rural Labour Force's Transference.

  4. A study on AB{sub 2}O{sub 6} compounds. Pt. V. A DFT study on charge balance as driving force for structural organisation

    Beck, Horst P. [Saarbruecken Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie


    In continuation of earlier investigations on the structures of AB{sub 2}O{sub 6} compounds we have remodelled those with A=Ca, Sr, Ba and B=As, Sb, V, Nb, Ta by relaxation in DFT calculations with the VASP code. The results match the real structures very closely. We have then calculated charges of the constituent atoms by means of a Bader analysis of the calculated electron density distribution. The results of these calculations are discussed with the aim to establish a correlation between the charges of the atoms and the vicinity structure around the atoms. Similar calculations were done first for all these compounds in a rosiaite type structure and second for CaAs{sub 2}O{sub 6} in all the other structures found for these compounds. We discuss how the balance of charges changes on forcing the systems into another topology, and we finally address the issue that structural organisation is strongly determined by the need to balance charges of the constituting elements in their specific stoichiometric relation.

  5. Driving-force compensation to improve the bias thermal stability of MEMS gyroscopes%改善MEMS陀螺误差温度稳定性的驱动力补偿方法

    刘宇航; 陈志勇; 张嵘


    由于微机电系统(MEMS)陀螺通常采用微加工工艺生产制造,因此总是受微加工过程带来的的各种精度缺陷影响.对于MEMS陀螺,其零位输出误差因受环境因素影响而无法保持稳定,随时间表现出漂移特性,这种特性严重限制了MEMS陀螺在更高精度应用中的可用性.该文研究了一种改善MEMS陀螺零位误差温度稳定性的方法.通过分析陀螺运动特性及主要误差源,阐明陀螺驱动力对检测方向的耦合作用是零偏误差同相分量产生并随温度漂移的主要原因之一.为抑制陀螺驱动力耦合作用,提出对陀螺检测轴施加补偿静电力的方法.温度试验结果表明:施加补偿作用后,陀螺零偏误差同相分量的温度稳定性在12~60℃范围内提高了3倍以上.%Micro electro mechanical system (MEMS) gyroscopes can be manufactured using micro-machining procedures,but they are all subject to unavoidable defects related to the fabrication processes.The zero-rate output (ZRO) of a MEMS gyroscope is known to vary with the environment which severely restricts high-precision applications.This paper presents a method to improve MEMS gyroscope thermal stability during temperature variations.Analysis of the gyro's error sources and fundamental dynamics show that the coupling of driving forces has a crucial effect on the in phase ZRO and also contributes to the instabilities of the gyro's bias.The coupling of the gyro driving forces can be suppressed by electrostatic force compensation applied to the sensing axis with temperature tests showing that the gyro bias is three times more stable after compensation for temperatures of 12 ~ 60℃.

  6. Does remnant gastric cancer really differ from primary gastric cancer? A systematic review of the literature by the Task Force of Japanese Gastric Cancer Association.

    Shimada, Hideaki; Fukagawa, Takeo; Haga, Yoshio; Oba, Koji


    Remnant gastric cancer, most frequently defined as cancer detected in the remnant stomach after distal gastrectomy for benign disease and those cases after surgery of gastric cancer at least 5 years after the primary surgery, is often reported as a tumor with poor prognosis. The Task Force of Japanese Gastric Cancer Association for Research Promotion evaluated the clinical impact of remnant gastric cancer by systematically reviewing publications focusing on molecular carcinogenesis, lymph node status, patient survival, and surgical complications. A systematic literature search was performed using PubMed/MEDLINE with the keywords "remnant," "stomach," and "cancer," revealing 1154 relevant reports published up to the end of December 2014. The mean interval between the initial surgery and the diagnosis of remnant gastric cancer ranged from 10 to 30 years. The incidence of lymph node metastases at the splenic hilum for remnant gastric cancer is not significantly higher than that for primary proximal gastric cancer. Lymph node involvement in the jejunal mesentery is a phenomenon peculiar to remnant gastric cancer after Billroth II reconstruction. Prognosis and postoperative morbidity and mortality rates seem to be comparable to those for primary proximal gastric cancer. The crude 5-year mortality for remnant gastric cancer was 1.08 times higher than that for primary proximal gastric cancer, but this difference was not statistically significant. In conclusion, although no prospective cohort study has yet evaluated the clinical significance of remnant gastric cancer, our literature review suggests that remnant gastric cancer does not adversely affect patient prognosis and postoperative course.

  7. A high force of plasmodium vivax blood-stage infection drives the rapid acquisition of immunity in papua new guinean children.

    Cristian Koepfli

    Full Text Available BACKGROUND: When both parasite species are co-endemic, Plasmodium vivax incidence peaks in younger children compared to P. falciparum. To identify differences in the number of blood stage infections of these species and its potential link to acquisition of immunity, we have estimated the molecular force of blood-stage infection of P. vivax ((molFOB, i.e. the number of genetically distinct blood-stage infections over time, and compared it to previously reported values for P. falciparum. METHODS: P. vivax (molFOB was estimated by high resolution genotyping parasites in samples collected over 16 months in a cohort of 264 Papua New Guinean children living in an area highly endemic for P. falciparum and P. vivax. In this cohort, P. vivax episodes decreased three-fold over the age range of 1-4.5 years. RESULTS: On average, children acquired 14.0 new P. vivax blood-stage clones/child/year-at-risk. While the incidence of clinical P. vivax illness was strongly associated with mol FOB (incidence rate ratio (IRR = 1.99, 95% confidence interval (CI95 [1.80, 2.19], (molFOB did not change with age. The incidence of P. vivax showed a faster decrease with age in children with high (IRR = 0.49, CI95 [0.38, 0.64] p<0.001 compared to those with low exposure (IRR = 0.63, CI95[0.43, 0.93] p = 0.02. CONCLUSION: P. vivax (molFOB is considerably higher than P. falciparum (molFOB (5.5 clones/child/year-at-risk. The high number of P. vivax clones that infect children in early childhood contribute to the rapid acquisition of immunity against clinical P. vivax malaria.

  8. 微陀螺梳齿静电驱动力的计算方法%The Calculation Method of the Electrostatic Drive Force of Micro Machined Groscope Comb

    姚峰林; 高世桥


    To calculate the electrostatic force in the micro machined gyroscope is a key problem in the mechanical characteristic of it. Base on the principle of electrostatic drive of the micro machined gyroscope, the paper introduces infinite plane model, edge-effect model and comer-effect model as the electrostatic field computation module of the micro comb. It deduces the formula of capacitance computation and electrostatic force of three models. By the numerical calculation and finite element calculation, it gets the capacitance and the electrostatic force of the gyroscope and the applicable circumstance of each model that the overlap length in variation. It suggests that the edge-effect and the corner-effect of comb should be fully considered when designing and computing the comb.%准确计算静电力是分析微机械陀螺力学特性的关键.文章基于微陀螺静电驱动原理,介绍了微梳齿结构的静电场计算的无限大平板模型,边缘效应模型,拐角效应模型三种模型.推导了三种模型的电容计算公式和静电力计算公式.通过数值计算和有限元计算,得到交叠长度变化时,不同计算模型的电容和静电驱动力的对比和各种模型的适用范围.说明在微尺度条件下静电场的边缘效应和拐角效应应当在设计和计算梳齿时应当充分考虑.

  9. 冷轧机附加倾斜后双侧非对称轧制力的计算%Asymmetric Roll Force Calculation With Additional Tilt for Drive Side and Operator Side of Cold Strip Mill

    刘宝权; 张鸿; 王自东; 王军生; 张岩


    对冷轧带钢轧制过程中因辊缝倾斜调整过量所导致的单边浪缺陷和断带进行了分析,应用影响函数法计算辊系变形,通过迭代计算出附加倾斜后的传动侧轧制力、操作侧轧制力、辊间压力分布、单位宽度轧制力分布、出口厚度横向分布、出口横向张应力分布。理论计算和实际测量结果表明,冷轧机双侧轧制力差值与倾斜调整量呈近似线性增长的规律。根据轧制力差值与倾斜量之间的比例关系,用实测轧制力差值对倾斜值进行动态限幅,可有效避免冷轧过程中断带事故的发生。%The single edge wave and strip break caused by excessive tilting adjustment were analyzed. Influence func tion method was adopted to model the roll deformation. Adding different tilt, roll force of drive side, roll force of operator side, transverse distribution of contact pressure between rolls, transverse distribution of roll force, trans verse distribution of strip thickness at exit side and transverse distribution of tension at exit side were calculated by using iterative method. The theoretical calculation and the actual measurement results show that the difference be- tween the bilateral increases almost linearly with tilt adjustment value. The break strip accidents are effectively aver ted by dynamic limiting to tilt setting value with the measured differential roll force, according to the proportional relationship between the differential roll force and the tilt.



    Land-use change is an important aspect of global environment change. It is, in a sense, the direct resultof human activities influencing our physical environment. Supported by the dynamic serving system of national resources,including both the environment database and GIS technology, this paper analyzed the land-use change in northeastern Chi-na in the past ten years (1990 -2000). It divides northeastern China into five land-use zones based on the dynamic de-gree (DD) of land-use: woodland/grassland - arable land conversion zone, dry land - paddy field conversion zone, ur-ban expansion zone, interlocked zone of farming and pasturing, and reclamation and abandoned zone. In the past tenyears, land-use change of northeastern China can be generalized as follows: increase of cropland area was obvious, pad-dy field and dry land increased by 74. 9 and 276. 0 thousand ha respectively; urban area expanded rapidly, area of townand rural residence increased by 76. 8 thousand ha; area of forest and grassland decreased sharply with the amount of1399. 0 and 1521.3 thousand ha respectively; area of water body and unused land increased by 148.4 and 513.9 thou-sand ha respectively. Besides a comprehensive analysis of the spatial patterns of land use, this paper also discusses thedriving forces in each land-use dynamic zones. The study shows that some key biophysical factors affect conspicuously theconversion of different land-use types. In this paper, the relationships between land-use conversion and DEM, accumulat-ed temperature(≥10℃) and precipitation were analysed and represented. We conclude that the land-use changes in north-east China resulted from the change of macro social and economic factors and local physical elements. Rapid populationgrowth and management changes, in some sense, can explain the shaping of woodland/grassland-cropland conversionzone. The conversion from dry land to paddy field in the dry land - paddy field conversion zone, apart from the

  11. Preliminary study for extension and improvement on modeling of primary water stress corrosion cracking at control rod drive mechanism nozzles of pressurized water reactors

    Aly, Omar F.; Mattar Neto, Miguel M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail:, e-mail:; Schvartzman, Monica M.M.A.M. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)], e-mail:


    This study is for to extend, to improve the existing models, and to propose a local approach to assess the primary water stress corrosion cracking in nickel-based components. It is includes a modeling of new data for Alloy 182 and new considerations about initiation and crack growth according a developing method based on EPRI-MRP-115 (2004), and USNRC NUREG/CR-6964 (2008). The experimental data is obtained from CDTN-Brazilian Nuclear Technology Development Center, by tests through slow strain rate test (SSRT) equipment. The model conception assumed is a built diagram which indicates a thermodynamic condition for the occurrence of corrosion submodes in essayed materials, through Pourbaix diagrams, for Nickel Alloys in high temperature primary water. Over them, are superimposed different models, including a semi-empiric-probabilistic one to quantify the primary water stress corrosion cracking susceptibility, and a crack growth model. These constructed models shall be validated with the experimental data. This development aims to extent some of the models obtained to weld metals like the Alloy 182, and to improve the originals obtained according methodologies exposed in above referred reports. These methodologies comprise laboratory testing procedures, data collecting, data screening, modeling procedures, assembling of data from some laboratories in the world, plotting of results, compared analysis and discussion of these results. Preliminary results for Alloy 182 will be presented. (author)

  12. POMDP-based Planning Model of Driving Force during Shield Tunneling%基于部分可观测Markov决策过程理论的盾构推进载荷规划

    胡祥涛; 张红旗; 李自成; 黄永安


    针对盾构掘进过程中位姿控制问题,提出了基于部分可观测马尔科夫决策过程(Partially observable Markov decision processes, POMDP)理论的推进载荷规划方法。在推进载荷规划模型中,将盾构自动纠偏看成不确定环境下序贯决策问题,充分考虑掘进过程中随机因素的影响,将盾构掘进过程中受到的阻力、推进载荷和盾构位姿分别定义为POMDP的状态集、行动集和观测集,然后重点讨论了信念状态、状态转移函数和观测函数等几个关键参数的获取方法。在计算值函数时,考虑了盾构位姿偏离程度和盾构载荷平稳程度对推进载荷决策的影响,建立了立即收益函数和长期折扣收益函数,并采用基于点的值迭代算法寻求推进载荷最优规划策略。针对天津地铁9号线进行了案例分析,结果表明基于POMDP的推进载荷规划方法是合理有效的,能够顺应掘进阻力随机变化。%In shield tunneling, the automatic control systems are mostly based on empirical relationships and do not have a precise theoretical background. Consequently, the present automatic control systems control the shield according to a snake-like motion to move it back onto the planned alignment. To solve such problems, an approach that adopts partially observable Markov decision processes (POMDP) theory to plan the driving force with explicit representation of the uncertainty during excavation is presented. In POMDP, the huge resistances during excavation, shield attitudes, and the driving force of possible world are scattered as the state set, observe set and action set, respectively. Furthermore, the deviations of shield attitude from planned alignment and the stationary of the loads acting on the shield are considered in the calculation of the value function. The experimental results confirm that the driving force planning based on POMDP is reasonable, and have certain ability of compliance at the


    赵莉莉; 杨文忠; 孟广涛; 范勋承


    Driving forces analysis is imperative in the study of land-use/cover changes (LUCC). We carried out a study on LUCC and its driving forces at village scale. Study pilots were 4 communities adjacent to the Gaoligongshan Nature Reserve in Nujiang River watershed of Northern Yunnan. SPOT-5 remote sensing images combining with field investigation were used to classify land use types and create classification system. Land use patterns and characteristics at village scale were analyzed by using Fragstats 3. 3. Meanwhile, socioeconomic data were obtained through household survey, semi-structure interviewing, and questionnaires. Relationship between land use pattern and socioeconomic status was built to analyze driving forces of LUCC. Results showed that land use was driven mainly by natural conditions,villagers' education level, and social customs. At the same time, households' cash incomes depended strongly upon extensive land uses. Study results provide quantified information for land resource management and village economic development in Nujiang River Watershed of Northern Yunnan. Methods we adopt can be used as a reference for LUCC studies at local scale.%驱动力分析是土地利用研究的重要内容。选择怒江流域北段高黎贡山自然保护区周边4个自然村为研究对象,应用高分辨率SPOT-5遥感影像数据,结合实地逐块核实,对土地利用/覆被进行分类,并建立土地利用类型分类系统,用Fragstats 3.3分析得到村域土地利用格局和特征;同时,采用入户调查、半结构访谈和问卷调查等方法,获得的村域详细社会经济数据,建立土地利用与社会经济之间的关联,分析村域土地利用的驱动力。结果显示:村域土地利用主要受自然条件、受教育程度、生活习俗等因子的驱动,且经济收入主要依赖于粗放的土地利用。研究结果能为怒江云南北段的土地资源合理利用和村域经济发展提供数据支持;研究方法

  14. PEEK Primary Crowns with Cobalt-Chromium, Zirconia and Galvanic Secondary Crowns with Different Tapers—A Comparison of Retention Forces

    Veronika Stock


    Full Text Available In prosthetic dentistry, double crown systems have proved their suitability as retainers for removable partial dentures. However, investigations in this context, regarding polyetheretherketone, are scarce. Therefore, the aim of this study was to test the retention force (RF between polyetheretherketone (PEEK primary and cobalt-chromium (CoCr, zirconia (ZrO2 and galvanic (GAL secondary crowns with three different tapers. Primary PEEK-crowns were milled with the tapers 0°, 1°, and 2° (n = 10/taper, respectively. Afterwards, 90 secondary crowns were fabricated: (i 30 CoCr-crowns milled from Ceramill Sintron (AmannGirrbach, Koblach, Austria (n = 10/taper, (ii 30 ZrO2-crowns milled from Ceramill ZI (AmannGirrbach, Koblach, Austria (n = 10/taper, and (iii 30 GAL-crowns made using electroforming (n = 10/taper. RF was measured in a pull-off test (20 pull-offs/specimen and data were analyzed using 2-/1-way Analysis of Variance (ANOVA followed by the Tukey-Honestly Significant Difference (HSD post hoc test and linear regression analyses (p < 0.05. The measured mean RF values ranged between 9.6 and 38.2 N. With regard to the 0°, 1°, and 2° tapered crowns, no statistically significant differences between CoCr and ZrO2 were observed (p > 0.141. At 0° taper, no differences in retention forces between GAL, CrCr, and ZrO2 crowns were found (p = 0.075. However, at 1° and 2° taper, lower RF for GAL-crowns were observed (p < 0.009, p < 0.001, respectively. According to this laboratory study, PEEK might be a suitable material for primary crowns, regardless of the taper and the material of secondary crown. Long-term results, however, are still necessary.

  15. Driving force and development strategies of agro-tourism in China%驱动因素视角的我国农业旅游发展模式与策略研究

    王灵恩; 何露; 成升魁; 闵庆文


    agro-tourism research and development in China for a more comprehensive knowledge about this sector. Foreign scholars have done so lot on the theory and empiricism of agro-tourism, community participation of women, diversification of operations, role of multi-functional agriculture and agro-heritage in tourism, impact of climate change on agro-tourism, sustainable development of agro-tourism, etc. Domestic scholars have focused mainly on empirical analysis of the concept of agro-tourism, state of development and countermeasures of agro-tourism, impacts of agro-tourism and festive tourism. This paper also analyzed the development of China's agro-tourism from the perspective of market demand, urbanization and rural economic restructuring. It discussed the driving forces of tourism demand, tourism development, accelerated urbanization, "re-turn-to-nature" drive, rural economic restructuring, agriculture, and tourism breakthrough achievement. Based on analysis of developments in China's agro-tourism, four driving forces were identified. The nation-wide tourism was driven by regional transportation, city development, scenic spot and resource monopoly. It was clear that the more driving factors there were, the more beneficial was the development of agro-tourism. The paper emphasized that under the concept of market economy, the development of agro-tourism always required a variety of external conditions for the jointly promotion of agro-tourism. Also with changing internal and external conditions, the driven factors for agro-tourism development changed. In conclusion therefore, development strategies were presented as the driving force of China's agro-tourism industry. Traffic-driven strategy and characteristics of product and urban development influenced strategic in-depth theme development of hot spot tourism sites. Link-driven development and unique-resource driven strategies were the brands of development for integrated mode of agro-tourism development. The development

  16. LAND USE CHANGE AND ITS SOCIO-ECONOMIC DRIVING FORCES UNDER STRESS OF PROJECT IN OLD RESERVOIR AREA --Case Study of Linshui Reservoir Area of Dahonghe Reservoir in Sichuan Province

    SHAO Jin-gan; HUANG Xue-qin; QU Ming; WEI Chao-fu; XIE De-ti


    The old reservoir areas built in 1950s-1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on interviewing with peasant households, combining land use survey and socio-economic statistical index, this paper analyzed land use change and its corresponding driving forces in Linshui reservoir area of Dahonghe Reservoir. Results showed that land use change in the reservoir area was mainly embodied on low-lying land submergence and migration requisition land. The former changed the land use patterns, and the latter mainly reconstructed original land property and made land over-fragmented. Cultivated land per capita was 0.041ha in this area, below the cordon of cultivated land per capita enacted by FAO. Currently, there were still 30.25% of peasant households being short of grain in trimester of one year, and there were 35.27% of people living under the poverty line. The conditions of eco-environment in Linshui Reservoir Area were worse, and healthy and sub-healthy eco-environment accounted for less proportion, composed of green belt around the reservoir area and paddy field ecosystem, and economic forest and orchard ecosystem, respectively. The stress of the reservoir project was macroscopic background to analyze the driving factors of land use change, and real underlying diving factor of the land use change in the area was the change of cultural landscape under the stress of reservoir project. The rapid increase of population was the key factor to induce the change of man-land relationship in the reservoir area, the low level of rural economy was the crucial factor to decide how migrants input for production, and the belief of migrants, influencing the land use patterns in a certain extent, was the inducing factor to keep land use stable. The low-lying submergence and infrastructure construction accompanied the reservoir project were leading

  17. 新疆博州地区土地利用变化及驱动力分析%Analysis of Land Use/Cover Change and Driving Force on Bo Zhou of Xinjiang Province Zone

    杜倩; 王勇辉


    The land use structure and the quality of land resource change constantly, because ot the natural factors and human factors, which results in the variation of the regional ecological environment and global environment. This article used the data of the land utilization in BoZhou of Xinjiang province from 2001 to 2009 to analyze its dynamic change. The conclusion is that farmland and land for household, industry, traffic and water conservancy facilities have increased in varying changes, while garden and grassland area have decreased. Afterwards, the social driving forces of the variation of land area in BoZhou were ana- lyzed quantitatively by analyzing the related data of social economy development, by the means of principal component analysis. We concluded that the adjustment of agricultural structure, economic development, production benefit, political and economic policies are main social driving forces causing variation of land u- tilization and the first industry is still in a dominant position.%由于受自然因素与人文因素的影响,土地利用结构以及土地资源质量不断变化,从而引起区域生态环境和全球环境的变化。文章运用新疆博州2000--2009年土地利用数据,分析其土地利用的动态变化情况,发现耕地、居民点及工矿用地、交通用地、水利设施都有不同程度的增加,园地与牧草地的面积有所减少。接着运用博州社会经济发展状况有关数据和主成分分析法对博州地区面积变化的社会驱动力作定量分析,总结出农业结构的调整、经济发展、农业生产效益、政治经济政策这4个因素是引起博州土地利用变化的主要社会驱动力因子,且第一产业仍然处于主导地位。

  18. 1976年以来江苏盐城滨海湿地景观变化及驱动力分析%Landscape changes of Jiangsu Yancheng coastal wetlands and their driving forces since 1976

    左平; 李云; 赵书河; 周鑫; 滕厚锋; 陈浩


    Temporal and spatial variations of landscape changes and their driving forces are analyzed in Yancheng coastal wetlands based on topography data in 1976 and remote sensing data in 1987, 1992, 1997, 2002 and 2007. The results show that the area of Yancheng natural coastal wetlands decreased gradually with the massive loss of Aeluropus sinensis, Suaeda glauca communities and great increase of fish pondsand agricultural lands. A landscape index shows Yancheng coastal wetlands are rapidly deteriorating and experiencing landscape fragmentation. Their driving forces are pushed by both human disturbance and physical conditions with policy-oriented activities of all kinds of wetlands development, alien species introduction and coastal erosion/accretion conditions. The existing development model on Yancheng coastal wetlands might be substituted by wise use and scientific management as soon as possible for the aim of biodiversity conservation and ecosystem health.%基于1976年的地形测绘数据和1987,1992,1997,2002,2007年的遥感数据提取土地利用和景观的时空变化,进而分析近40 a来江苏盐城滨海湿地的景观变化和驱动力.研究表明:自1976年以来盐城滨海湿地中的自然湿地总面积呈逐渐减少的趋势;景观的主要变化特征表现为以獐茅、碱蓬群落为代表的自然湿地的大面积减少,和以鱼塘、农业用地为代表的人工湿地的大面积增加.景观指标分析表明盐城滨海湿地景观总体上有破碎化程度加剧的趋势.结果分析认为,这种变化既受到政策导向型的各类滩涂开发等人为干扰活动的影响,也受到滨海湿地自然演化和潮滩蚀淤等自然因素的影响.尽快改变盐城滨海湿地现有的开发利用模式,使各种人类活动对整个生态系统的压力减到最小,以获得经济、社会、生态效益的统一.

  19. Design and static performance of high speed machining centre with "direct drive"

    Shuhong XIAO; Yulian CHEN; Guangyuan ZHENG


    "Direct drive" is an ideal method for speeding machine tools. In the structure of a CNC machining centre with "direct drive", the linear motor's primary and secondary parts are assembled into the worktable and machine bed respectively to directly drive the worktable. The built-in rotary motor is assembled in the spindle to realize the main transmission system of the machine tool "direct drive". All mechanical transmission elements in machine tools are eliminated. High speed, efficiency, and accuracy are easily obtained. However, in this type of "direct drive" machining centre, the magnetic attraction force between the primary and the secondary linear motors and the dynamic impact at acceleration and deceleration are directly imposed on the machine tool, and influence the performance of the machining centre. This paper analyzes the special demands of "direct drive" on the machine centre, and introduces a new structure of the machining tool. The worktable and machine bed are optimized to meet the special demands of "direct drive". Static performance simulation on the machining centre is done to reveal an ideal result.

  20. Water drives peptide conformational transitions

    Nerukh, Dmitry


    Transitions between metastable conformations of a dipeptide are investigated using classical molecular dynamics simulation with explicit water molecules. The distribution of the surrounding water at different moments before the transitions and the dynamical correlations of water with the peptide's configurational motions indicate that water is the main driving force of the conformational changes.

  1. Death Drive in Tourism Studies

    Buda, Dorina


    The psychoanalytical concept of the death drive refers to a constant metapsychological force at the junction between life and death: it is not understood in a biological sense of physical demise of the body, nor in opposition to life. Geographies of tourist performances in places in the proximity of

  2. Death Drive in Tourism Studies

    Buda, Dorina


    The psychoanalytical concept of the death drive refers to a constant metapsychological force at the junction between life and death: it is not understood in a biological sense of physical demise of the body, nor in opposition to life. Geographies of tourist performances in places in the proximity of

  3. Standardization of Mobile Satellite Service Technology in ITU-R:Driving Force of Integrated Mobile Services%ITU-R卫星移动通信标准--整合移动业务的动力



    认为国际电信联盟无线电通信部门(ITU-R)关于卫星移动通信的标准化新进展将在全球移动通信设备和系统无缝连接的实现过程中起到重要作用,卫星和地面的集成/混合的天地一体化系统将充分发挥原系统各自的优势,未来多数的卫星移动业务(MSS)都将基于这种天地一体化系统。指出IMT-Advanced系统的卫星部分和ITU-R标准化无线接口是集成MSS系统的关键技术,将成为激活MSS产业的新的驱动力。%Wel-developed standards wil play an important role in facilitating seamless interworking of equipment and systems global y. Most future MSS services wil use integrated and/or hybrid satel ite-terrestrial networks that leverage both satel ite and terrestrial networks. Satel ite components of IMT-Advanced systems and ITU-R standardized radio interfaces provide key technology in integrated satel ite and terrestrial networks, and this wil be a new driving force behind MSS industries.

  4. [Study on the types and water pollution driving forces of the typical and medium-small-sized cities in the southern China based on the analysis of water environment].

    Jiao, Shi-Xing; Wang, La-Chun; Huo, Yu; Chen, Chang-Chun; Teng, Juan


    According to the major pollution sources of urban water environment, 10 indexes such as industrial sewage quantity were closen to establish evaluation indexes system about the types and influencing factors of the typical and medium-small-sized cities in the southern China. Case studies of 16 typical and medium-small-sized cities were taken in Jiangsu, Zhejiang, Hubei and Anhui provinces. Combined with SPSS 11.0 cluster analysis results, city types were divided in reference to the values of water resources comprehensive pollution indexes and economical development indexes. The driving forces about city water environment pollution were studied by principal component analysis method. The result indicates that the 16 cities belong to two categories and four sub-categories, which are rich economy as well as light pollution of water environment and poor economy as well as heavy pollution of water environment. The influencing factors of water environment pollution are in sequence of industrial water pollution, agricultural no-point source pollution and urban domestic water pollution. The main factors of water environment pollution influenced I category cities, II as well as IV category cities and III category cities are industrial water pollution, urban domestic pollution and agricultural no-point source pollution respectively.

  5. Research on Driving Forces of the Education of Martial Arts Morality in Promoting the Development of Teenagers%武德教育对促进青少年健康成长的内驱力研究



    本文以武德教育和青少年德育为研究对象。结合青少年发育过程中的生理、心理特征,以武德教育为突破口进行研究。分析了现阶段我国青少年思想道德教育中存在的问题;论述了武德教育的时代特性;探讨了武德教育促进青少年健康成长的有机融合研究;提出了武德教育驱动青少年德育建设的有效途径。%This paper takes the education of martial arts morality and teenagers'morality as its research object. The research is carried out by taking its breakthrough from the education of martial arts morality while connecting biological and psychological characteristics of teenagers.It analyzes problems existing in morality education among Chinese teenagers at present and discusses features of education of martial arts morality in modern times.By exploring the organic integration of education of martial arts into the development of teenagers,it proposes effective ways of enhancing driving forces of education of martial arts morality in promoting teenagers'morality.

  6. A comparison of the Wheeler-Jonas model and the linear driving force at constant-pattern model for the prediction of the service time of activated carbon cartridges.

    Grévillot, Georges; Marsteau, Stéphanie; Vallières, Cécile


    The linear driving force (LDF) model is applied to predict the service life of activated carbon cartridges. It is compared with the currently used Wheeler-Jonas equation, which results from a model of chemical reaction kinetics. The LDF model is based on a mass transfer model of adsorbate into the particle. The two models are studied in constant-pattern conditions. The properties of the two models are first clarified and then compared. It is shown that the Wheeler-Jonas equation leads to symmetrical breakthrough curves, whereas the constant-pattern LDF equation results in asymmetrical curves. Thus, the curvature of the isotherm has no influence on the shape of the Wheeler-Jonas curve. For the LDF breakthrough curve, it is shown that the asymmetry increases with the curvature of the isotherm. Wheeler-Jonas can be used with a Dubinin-Raduskevitch isotherm, whereas the LDF model analytical solution is valid for a Langmuir isotherm only. The LDF model can be used with the DR isotherm, but a numerical solution is required. At very low concentrations where the isotherm is linear, the constant pattern no longer exists and both models fail. The Dubinin-Raduskevitch isotherm must be fitted with a Langmuir isotherm to use the analytical solution of the LDF model.

  7. [Using the 'Driving Force - Pressure - State - Exposure - Effects - Action' (DPSEEA) model of the World Health Organization (WHO) for the analysis of risks related to the use of pesticides in agricultural activities in the state of Rio de Janeiro].

    Araújo-Pinto, Mariana de; Peres, Frederico; Moreira, Josino Costa


    This paper seeks to apply the DPSEEA model (WHO) to identify major health risks to rural workers and the environment associated with the intensive use of pesticides in the State of Rio de Janeiro, based on an analysis of official public documents and a review of the (national and international) literature. It emphasizes the two main representative branches of agriculture in the state: family farming in the mountain region and the monoculture of sugarcane in the flatlands. Results show that the bulk of the determinants identified in the DPSEEA Matrix are related to deficiencies in actions for monitoring and surveillance of pesticide use, as well as a lack of technical assistance provided by the Public Sector in Rio de Janeiro State. Most of the actions developed in the state address the effects of pesticide exposure and, to a lesser extent, exposure to these chemicals, failing to focus on the higher levels of the matrix (such as driving forces and pressure). These are considered, by several authors, as the most appropriate when tackling the complex and systemic issues, such as the scope of this paper. By means of this study, an attempt was made to enable the application of the DPSEEA Model to assist in environmental and occupational health surveillance initiatives.

  8. Improvement in precision grip force control with self-modulation of primary motor cortex during motor imagery

    Maria Laura eBlefari


    Full Text Available Motor imagery (MI has shown effectiveness in enhancing motor performance. This may be due to the common neural mechanisms underlying MI and motor execution (ME. The main region of the ME network, the primary motor cortex (M1, has been consistently linked to motor performance. However, the activation of M1 during motor imagery is controversial, which may account for inconsistent rehabilitation therapy outcomes using MI. Here, we examined the relationship between contralateral M1 (cM1 activation during MI and changes in sensorimotor performance. To aid cM1 activity modulation during MI, we used real-time fMRI neurofeedback-guided MI based on cM1 hand area blood oxygen level dependent (BOLD signal in healthy subjects, performing kinesthetic MI of pinching. We used multiple regression analysis to examine the correlation between cM1 BOLD signal and changes in motor performance during an isometric pinching task of those subjects who were able to activate cM1 during motor imagery. Activities in premotor and parietal regions were used as covariates. We found that cM1 activity was positively correlated to improvements in accuracy as well as overall performance improvements, whereas other regions in the sensorimotor network were not. The association between cM1 activation during MI with performance changes indicates that subjects with stronger cM1 activation during MI may benefit more from MI training, with implications towards targeted neurotherapy.

  9. Land Use and Land Cover Change in Taohe River Basin and Its Driving Forces%洮河流域土地利用/土地覆被变化及其驱动机制研究

    李常斌; 杨林山; 杨文瑾; 王帅兵


    The purpose of this article is to detect the land use and land cover change (LULCC) in Taohe River Basin (TRB) from 1980s to the 2000s and explore its main driving forces. We first build a database of the LULCC by collecting and reorganizing the land use and land cover maps and images, along with data from hy-drometeorologic and socio-economic surveys. The methods that we adopt for estimating the LULCC include the comprehensive utilization index, the transition matrix, and the dynamic index. Correlation analysis and principal components analysis (PCA) are then used for identifying the socioeconomic driving factors of the LULCC before the driving mechanisms are determined through fitting the Multiple Linear Regression Expres-sions (MLREs) to every land use type. It is found that forestland and grassland decreased while cultivated land increased over the past 30 years, despite the obvious heterogeneities in time and space. Temporally, cultivated land and forestland experienced a decline while grassland gained during 1980 s-1990 s;thereafter, cultivated land increased at the expense of forestland and grassland. Spatially, forestland and grassland in the upper and middle reaches of the TRB reduced but cultivated land grew;in the lower reaches, opposite trends took place. Overall, change in cultivated land was the most significant of all land-use types, and both deforestation and af-forestation went on simultaneously. Correlation analysis and PCA show that the LULCC in the TRB were driv-en mostly by the regional economic development, and that the main types of land use-cultivated land, forest-land, and grassland-were also affected by agricultural growth, featuring farming population and area expan-sion. The small categories of land uses-built-up land and water body were influenced by a combined set of"re-gional economy + farming factors + urbanization and climate" driving mechanism. Accordingly, the MLREs were fitted with satisfactory accuracies for both calibration and

  10. Error signals driving locomotor adaptation

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo


    perturbations. Forces were applied to the ankle joint during the early swing phase using an electrohydraulic ankle-foot orthosis. Repetitive 80 Hz electrical stimulation was applied to disrupt cutaneous feedback from the superficial peroneal nerve (foot dorsum) and medial plantar nerve (foot sole) during...... anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. Our results suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when...

  11. 基子集成商视角韵复桑产品系统创新驱动力研究%Research on the Innovation Driving Forces of Complex Products and Systems based on the Perspective of Integrators

    苏敬勤; 刘静


    本文采用单案例研究方法,从系统集成商的视角对DJ公司进行了探索性案例研究,运用内容分析法归纳提炼出13个影响DJ公司产品创新的观测变量,形成实证研究量表,并通过问卷调查收集了118个样本数据,运用探索性因子分析的方法对影响因素进行了提取,得出影响复杂产品系统创新的三个主成分因子,即市场控制力、核心技术控制力和动态能力,构成复杂产品系统创新的驱动力主成分。%Complex Products and Systems(COPS) industries play important roles in the economic prosperity of China. CoPS show peculiar features in terms of product characteristics and innovation process. They are custom ized, costly, and technologyintensive products, systems, services, and infrastructure manufactured in single or small batches. During the CoPS innovation process, a system integrator's capabilities directly affect the quality and efficiency of CoPS projects. However, system integrators will not be productive unless they can identify the key fac tors which affect the process of CoPS projects. Because of those different features compared with ordinary masspro duced products theories about product innovation can not available to explain what key factors affect the innovation efficiency of COPS. Therefore, this study highlights the different dimensions of key factors and effects on product in novation in complex product systems innovation and aims to explore drivinz forces (kev factors) of CoPS innovation. In this paper, we used two methods to explore main elements of driving forces (key iactors)of CoPS innova tion. Firstly, the single exploratory case study method is adopted. DL was chose as our case, since the foundation of the People's Republic of China, the Company has successively experienced six large scale technology transforma tions and step by step turned into a modern enterprise being able to design and manufacture highlevel diesel

  12. What drives the spatial variability of primary productivity and matter fluxes in the north-west African upwelling system? A modelling approach

    Auger, Pierre-Amaël; Gorgues, Thomas; Machu, Eric; Aumont, Olivier; Brehmer, Patrice


    A comparative box analysis based on a multi-decadal physical-biogeochemical hindcast simulation (1980-2009) was conducted to characterize the drivers of the spatial distribution of phytoplankton biomass and production in the north-west (NW) African upwelling system. Alongshore geostrophic flow related to large-scale circulation patterns associated with the influence of coastal topography is suggested to modulate the coastal divergence, and then the response of nutrient upwelling to wind forcing. In our simulation, this translates into a coastal upwelling of nitrate being significant in all regions but the Cape Blanc (CB) area. However, upwelling is found to be the dominant supplier of nitrate only in the northern Saharan Bank (NSB) and the Senegalo-Mauritanian (SM) regions. Elsewhere, nitrate supply is dominated by meridional advection, especially off Cape Blanc. Phytoplankton displays a similar behaviour with a supply by lateral advection which equals the net coastal phytoplankton growth in all coastal regions except the Senegalo-Mauritanian area. Noticeably, in the Cape Blanc area, the net coastal phytoplankton growth is mostly sustained by high levels of regenerated production exceeding new production by more than twofold, which is in agreement with the locally weak input of nitrate by coastal upwelling. Further offshore, the distribution of nutrients and phytoplankton is explained by the coastal circulation. Indeed, in the northern part of our domain (i.e. Saharan Bank), the coastal circulation is mainly alongshore, resulting in low offshore lateral advection of nutrients and phytoplankton. Conversely, lateral advection transports coastal nutrients and phytoplankton towards offshore areas in the latitudinal band off the Senegalo-Mauritanian region. Moreover, this latter offshore region benefits from transient southern intrusions of nutrient-rich waters from the Guinean upwelling.

  13. Collaboration: The Driving Force for Success

    Rourke, James; Boone, Elizabeth


    Nestled in the mountains and surrounded by Christmas tree farms, Ashe County Middle School is a small, rural school in the far northwest corner of North Carolina. Recognized nationally for its fine academic and co-curricular programs, the school prepares students for high school and real-life situations by teaching important concepts, essential…

  14. Three Driving Forces of Labor Market

    Gao Zhanqiang


    @@ The sub prime in Wall Street of USA finally turned into global economic crisis. China, as the second largest export country in the world, caught in the biting cold economic storm. As the declining export directly plays on the weakness of Chinese economy, shrinking domestic demand and weak export market worsens the employment situation in China.

  15. Pattern-formation under acoustic driving forces

    Valverde, Jose Manuel


    Chemical and metallurgical processes enhanced by high intensity acoustic waves, thermoacoustic engines and refrigerators, fuel rods in nuclear reactors, heat exchanger tubes, offshore and vibrating structures, solar thermal collectors, acoustic levitators, microfluidic devices, cycling, musical acoustics, blood flow through veins/arteries, hearing in the mammalian ear, carbon nanotube loudspeakers, etc. The evolution of a myriad of processes involving the oscillation of viscous fluids in the presence of solid boundaries is up to a certain extent influenced by acoustic streaming. In addition to the sound field, viscous energy dissipation at the fluid-solid boundary causes a time-independent fluid circulation, which can lead to a significant enhancement of heat, mass and momentum transfer at large oscillation amplitudes. A particularly relevant phenomenon that can be notably affected by acoustic streaming is the promotion of sound waves by temperature gradients or viceversa (thermoacoustics), which is at the basis of potentially efficient and environmental friendly engines and refrigerators that have attracted a renewed interest in the last years. In the present manuscript, historical developments and the underlying basic physics behind acoustic streaming and thermoacoustics are reviewed from an unifying perspective.

  16. The driving force role of ruthenacyclobutanes

    Vummaleti, Sai V. C.


    DFT calculations have been used to determine the thermodynamic and kinetic preference for ruthenacyclobutanes resulting from the experimentally proposed interconversion pathways (olefin and alkylidene rotations) through the investigation of cross-metathesis reaction mechanism for neutral Grubbs catalyst, RuCl2(=CHEt)NHC (A), with ethylene and 1-butene as the substrates. Our results show that although the proposed interconversions are feasible due to the predicted low energy barriers (2-6 kcal/mol), the formation of ruthenacyclobutane is kinetically favored over the competitive reactions involving alkylidene rotations. In comparison with catalyst A, the reaction energy profile for cationic Piers catalyst [RuCl2(=CHPCy3)NHC+] (B) is more endothermic in nature with both ethylene and 1-butene substrates.

  17. SINEs as driving forces in genome evolution.

    Schmitz, J


    SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution.


    Trunev A. P.


    Full Text Available The article presents the theory of the electromagnetic type of rocket motor. The apparatus consists of a magnetron and a conical cavity in which electromagnetic oscillations are excited. We explain the mechanism of trust in such a device based on Maxwell's theory and the Abraham force. We built a dynamic model of the motor and calculated the optimal parameters. It is shown, that the laws of conservation of momentum and energy for the rocket motor of electromagnetic type are true, taking into account the gravitational field. In simulation, the movement used the theory of relativity. The source of the motion in an electromagnetic drive is the mass conversion in various kinds of radiation. The optimization of the operating parameters of the device is done, namely by the excitation frequency, the magnitude of heat losses of electromagnetic energy by thermal radiation in the IR spectrum, the parameters of heat transfer and forced from the temperature dependence of the resistance of the material of the cavity walls. It was found that the effective conversion of electromagnetic energy in the trust force necessary to minimize the deviation of the excitation frequency of the primary resonance frequency of the cavity. The mechanism of formation of trust under change the metrics of space-time, taking into account the contribution of the Yang-Mills theory and electromagnetic field tensor of energymomentum has been proposed

  19. Conceptual Design Study on Electromagnets of Control Rod Drive Mechanism of a SFR

    Lee, Jaehan; Koo, Gyeonghoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The prototype SFR has six primary control rod assemblies(CRAs) and three secondary shutdown assemblies. The primary control system is used for power control, burnup compensation and reactor shutdown in response to demands from the plant control or protection systems. This paper describes the design concept of primary control rod drive mechanism shortly, and performs the parametric design studies for the electromagnet device of the drive mechanism to maximize CRA gripping force. The electromagnetic core usually confines and guides the magnetic field. The major parameters influenced on the electromagnetic force are the geometry and arrangement of the electromagnet and armature for a given coil specification. A typical equation calculating the electromagnetic force for a solenoid type is represented in equation. The first one is the increasing of the flux cross section area (Α{sub c}, Α{sub g}) in magnetic field connecting of air gap, armature and electromagnets. Secondly, the reducing of the path lengths (l{sub c}, l{sub g}) of the armature and electromagnet makes the magnetic flux (Β) resistance to be low. An electromagnet field analyses are performed for the initial design values of the electromagnet device. The gripping force is about 3 times of CRA weight when one coil is power on. The parametric studies on air gap, core sizes configuring of the electromagnet cores are performed to maximize the electromagnetic force.

  20. Driving Forces and Equilibrium Analysis of Social Responsibility in Marine Aquatic Products Supply Chain%海洋水产品供应链社会责任驱动力和平衡分析

    姜启军; 胡珂


    Food safety,food information transparency,environmental pollution,ecological destruc-tion,climate change and other issues are the crucial problems of corporate social responsibility in marine aquatic products supply chain,but have been ignored for a long time.Aquaculture is pros-perous in China.In recent years,the safety issues of China’ s marine aquaculture emerge all the time,such as excessive drug residues in breeding section,unstandardized operation in processing stages and the abuse of preservatives in the transport and storage process,etc..These have caused serious damage to consumers’ health.It is precisely because of the lack of the driving force in per-forming the social responsibility of member enterprises in marine aquatic products supply chain, which has led to frequent safety problems of aquatic products.This paper argued that the driving force of CSR (corporate social responsibility)came from the core enterprise in the food supply chain,and the pressure about CSR was different between large enterprises and small and medium-sized enterprise in the whole supply chain.The imbalance of market power in supply chain would have an adverse effect on CSR’ s performance for small and medium-sized food enterprises,and in-duced CSR clashes between supply chain members.A relative balance situation about CSR of the enterprises in the supply chain was needed to be achieved to obtain stability in the supply chain.%食品安全、食品信息透明度、海洋环境污染、生态破坏、气候变化等是海洋水产品供应链社会责任的主要问题,但长期被我们忽视。中国是水产养殖大国,近年来我国海洋水产品供应链中食品安全问题层出不穷,如养殖环节药残超标、加工环节操作不规范、仓储与运输过程中滥用防腐剂等,严重损害消费者的身心健康。正是由于水产品供应链中的成员企业缺少履行社会责任的驱动力,才导致水产品安全问题频发。文章

  1. 郑州市生态环境脆弱性演变及驱动力分析%Vulnerability Evolution and Driving Force Analysis of Zhengzhou Ecological Environment

    付占辉; 李盼婷; 王岩松; 何伟纯


    Proceeded from the multi-factor and angle that affected the vulnerability of ecological environment ,the comprehensive vulnerability of ecological environment in Zhengzhou during 1990 to 2013 was analyzed based on the entropy evaluation method,moreover,the driving forces of that were discussed by using the PCA(principal component analysis). The results showed as follows.(1)On the whole Zhengzhou ecological environment comprehensive vulnerability showed a slow downward trend from 1990 to 2013. Looked from the evolution process, that trend could be divided into two phases:wave decline stage from 1990 to 2002 and volatility rising stage from 2003 to 2013;(2)From the system data,there existed great differences between the three subsystems,among them the pressure index and fragile ecological environment bearing capacity index showed a trend of volatility ,while the fragile ecological environment stress index showed a trend of sustained and rapid decline;(3)Through analyzing the selected 13 factors by using PCA,all the indexes passed inspection. The results showed that the economic development and urbanization development factors were the main driving forces of Zhengzhou ecological environment comprehensive vulnerability.%从影响生态环境脆弱性的多因素多角度出发,基于熵值法对郑州市1990—2013年生态环境综合脆弱性进行分析,并运用主成分分析法探讨了1990—2013年生态环境综合脆弱性的驱动力.结果表明:①郑州市1990—2013年生态环境综合脆弱性总体上呈波动缓慢下降趋势,从演变过程看,可以分为波动下降阶段(1990—2002)和波动上升阶段(2003—2013).②从系统层指标来看,子系统指标之间存在着较大的差异,其中,生态环境压力指数和生态环境承载力脆弱性指数呈波动上升趋势,而生态环境抗压力脆弱性指数呈持续快速下降趋势.③将选取的13个因子进行主成分分析,各项指标均通过

  2. 宁夏中部干旱带土地利用变化及驱动力分析%Analysis on Land Use Change and Its Driving Forces in Arid Area of Central Ningxia Hui Autonomous Region

    贾科利; 张俊华


    By using data derived from the 1978 MSS image and 1987,1996,2007 Landsat TM/ETM images and with the help of GIS,the land use change in arid area of central Ningxia Hui Autonomous Region was analyzed.At the same time,the driving forces of the land use change was identified by making use of the correlation analysis and principal component.The results showed that the overall trend of land use change in arid area of central Ningxia Hui Autonomous Region was in an enlargement of the areas of cultivated land,urban land,whereas sandy land area decreased 281 682 hm2,an average annual increase rate grassland area was 0.17%,and area of forest land reduced nearly 30 000 hm2 over 30 years.The land use information entropy indicating that the degree of disorder for land use system increased,and the structure of land use became complexity and diversity.It was considered that population,economic,regional socio-economic development degree,industrial structure,agricultural production,socio-input,government policy,and natural factors are the main driving forces inducing land use change in arid area of central Ningxia Hui Autonomous Region.More importantly,the principal component analysis showed that the impacts of human activity combining with some other conditions were the leading factors that induced dynamic change of the 1and use.%利用1978年MSS、1987年、1996年及2007年TM遥感影像,借助遥感和GIS技术及相关分析、主成分分析方法,对宁夏中部干旱带1978-2007年土地利用变化及驱动力进行了分析。结果表明:1978-2007年耕地、城镇用地面积快速增加,沙地面积减少了281 682hm2。草地以年均0.17%的速率不断增加,林地面积减少了近3万hm2。土地利用系统无序化程度增加,土地利用利用结构复杂性和多样性增大。人口、经济、产业结构、农业生产、投入、富裕程度、政策和自然因素是驱动研究区土地利用变化的主要因素,其中,人口作为社会经济活

  3. The Driving Force Mechanism and Control Strategy of a Pneumatic Hydrostatic Soft Robot%一种气动静压软体机器人的驱动力产生机理及控制策略

    郑俊君; 宋小波; 姜祖辉; 谭治英


    Traditional robots with complicated rigid structure will be worn and teared when running in a cramped and diverse space. For this problem, a new model of pneumatic hydrostatic force soft robot is presented, and the resistance and motion loss are reduced while robots pass the cramped space. Based on sea cucumbers’ hydrostatic bone structure, a soft robot with airbag phase transition structure is designed, the hydrostatic mechanical property of the airbag’s charging and discharging process is analyzed, and a mathematical model of driving force is set up. Thus, single-unit and double-unit control policies are designed, meanwhile, a time-stamped BP (backpropagation) neural network is used to predict delay time for increasing the stability of internal model feedback control. According to obstacle surmounting tests and stability analysis tests, the robot with delay prediction can move stably and cross small gaps smoothly by single-unit and double-unit control strategy, and the probability of turning over six units increases from 89%to 96%.%基于复杂刚性结构的传统机器人在狭小多变的空间中活动时,易对机器人本体产生较大磨损与消耗。针对此类问题,本文提出一种新型气动静压软体机器人,降低了机器人通过狭小空间时的阻力,减少运动损耗。在研究海参静水骨骼结构基础上,设计了软体机器人气囊相变结构,分析了气囊充放气的流体静压力学特性,建立驱动力产生的数学模型,从而设计出单单元与双单元控制策略,并利用时间戳BP(反向传播)神经网络对系统的延时时间进行预测,增强内模反馈系统的稳定性。在越障实验与稳定性分析中,加入延时预测后,机器人能在单单元与双单元控制模式下稳定行进,并顺利越过小沟壑,顺利完成六单元翻转的概率从89%提高到96%。

  4. 红门川流域土地利用景观动态演变及驱动力分析%Analysis on dynamic evolution and driving force of land-use landscape in Hongmenchuanbasin

    赵阳; 余新晓; 贾剑波; 刘旭辉


    Analysis of the land use and land cover changes (LUCC) and its driving factors in water conservation zones is essential for the development of sustainable water resource strategies. Miyun Reservoir is the most important drinking water source for Beijing Municipality, the capital of China with a population of more than 20 million.In recent decades,the inflow to the reservoir has shown a decreasing trend,which has seriously threatened the security of water use in Beijing. According to researches, LUCC is generally assumed to be responsible for changes in water yield of catchments. In order to explore the evolution process and driving factors of landscape changes in water source protection zones of the metropolitan area, Hongmenchuan watershed located in Miyun County was selected as the research object. The characteristics and the dynamic evolution of landscape patterns during 1990 to 2005 were analyzed by applying landscape ecological method and Markov model on the basis of the land use information from remote sensing. Combined with Grey forecast model of GM (1, 1) and the principal components analysis, the driving force of landscape changes were discussed from three aspects of the socio-economic, the natural conditions and regional policy and the population, respectively. Brief conclusions can be drawn as follows:major LULC changes in the period from 1990 to 2005 include declines of water area, and major increases in urban area. Moreover, the rapid reduction of water area and the continued increase of construction land were the most obvious features of the landscape changes in Hongmenchuan watershed during the period of 1990-2005. Changes of comprehensive dynamic degree of land use in different periods indicated that land use change rate showed an accelerated increasing trend. Landscape fragmentation increased significantly and patches distribution of various landscape types tend to be gathered, which lead to the patches shape more complicated. Based on the

  5. 1983-2001年中国北方的耕地变化与驱动力%Understanding cultivated land dynamics and its driving forces in northern China during 1983-2001

    何春阳; 李景刚; 王圆圆


    Based on the long-term serial NOAA/NDVI dataset during 1983-1999 and SPOT/VGT dataset in 2001, the land use/cover change information in the 13 provinces of northern China was extracted based on the analysis of the cultivated landscape characteristics at first, then the effects of human activities on cultivated land process were explored by GIS and the driving forces of cultivated land change were investigated. The conclusions can be drawn as follows: (1) The constant increase of weak ecological function land as desert and cultivated land and the decrease of the ecological function land of forest and shrub were the main characteristics of the land use/cover change in the 13 provinces from 1983 to 1999, which showed the effects on the ecological adjustment function. However, such situations were changed to some extent in the 2000s because of the eco-construction policy of the government. (2) From 1983 to 2001, the Barycenter of cultivated land tended to move from northeast to southwest with the topography and transportation situations being the main influences on the cultivated land distribution. It is found that the cultivated land use intensity decreased noticably with the increase of distance from the main communication arteries. (3) The improvement of the people's living standard is closely related with the cultivated land change. The structural adjustment in the agricultural land caused by economic development and the improvement of the people's living standard is an important factor affecting the cultivated land change in northern China from 1983 to 2001.

  6. Characterization of New Isolates of Apricot vein clearing-associated virus and of a New Prunus-Infecting Virus: Evidence for Recombination as a Driving Force in Betaflexiviridae Evolution.

    Armelle Marais

    Full Text Available Double stranded RNAs from Prunus samples gathered from various surveys were analyzed by a deep-sequencing approach. Contig annotations revealed the presence of a potential new viral species in an Azerbaijani almond tree (Prunus amygdalus and its genome sequence was completed. Its genomic organization is similar to that of the recently described Apricot vein clearing associated virus (AVCaV for which two new isolates were also characterized, in a similar fashion, from two Japanese plums (Prunus salicina from a French germplasm collection. The amino acid identity values between the four proteins encoded by the genome of the new virus have identity levels with those of AVCaV which fall clearly outside the species demarcation criteria. The new virus should therefore be considered as a new species for which the name of Caucasus prunus virus (CPrV has been proposed. Phylogenetic relationships and nucleotide comparisons suggested that together with AVCaV, CPrV could define a new genus (proposed name: Prunevirus in the family Betaflexiviridae. A molecular test targeting both members of the new genus was developed, allowing the detection of additional AVCaV isolates, and therefore extending the known geographical distribution and the host range of AVCaV. Moreover, the phylogenetic trees reconstructed with the amino acid sequences of replicase, movement and coat proteins of representative Betaflexiviridae members suggest that Citrus leaf blotch virus (CLBV, type member of the genus Citrivirus may have evolved from a recombination event involving a Prunevirus, further highlighting the importance of recombination as a driving force in Betaflexiviridae evolution. The sequences reported in the present manuscript have been deposited in the GenBank database under accession numbers KM507061-KM504070.

  7. Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans.

    Hortobágyi, Tibor; Richardson, Sarah Pirio; Lomarev, Mikhael; Shamim, Ejaz; Meunier, Sabine; Russman, Heike; Dang, Nguyet; Hallett, Mark


    Although there is consensus that the central nervous system mediates the increases in maximal voluntary force (maximal voluntary contraction, MVC) produced by resistance exercise, the involvement of the primary motor cortex (M1) in these processes remains controversial. We hypothesized that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of M1 during resistance training would diminish strength gains. Forty subjects were divided equally into five groups. Subjects voluntarily (Vol) abducted the first dorsal interosseus (FDI) (5 bouts x 10 repetitions, 10 sessions, 4 wk) at 70-80% MVC. Another group also exercised but in the 1-min-long interbout rest intervals they received rTMS [Vol+rTMS, 1 Hz, FDI motor area, 300 pulses/session, 120% of the resting motor threshold (rMT)]. The third group also exercised and received sham rTMS (Vol+Sham). The fourth group received only rTMS (rTMS_only). The 37.5% and 33.3% gains in MVC in Vol and Vol+Sham groups, respectively, were greater (P = 0.001) than the 18.9% gain in Vol+rTMS, 1.9% in rTMS_only, and 2.6% in unexercised control subjects who received no stimulation. Acutely, within sessions 5 and 10, single-pulse TMS revealed that motor-evoked potential size and recruitment curve slopes were reduced in Vol+rTMS and rTMS_only groups and accumulated to chronic reductions by session 10. There were no changes in rMT, maximum compound action potential amplitude (M(max)), and peripherally evoked twitch forces in the trained FDI and the untrained abductor digiti minimi. Although contributions from spinal sources cannot be excluded, the data suggest that M1 may play a role in mediating neural adaptations to strength training.

  8. Characterization of systemic disease in primary Sjögren's syndrome: EULAR-SS Task Force recommendations for articular, cutaneous, pulmonary and renal involvements.

    Ramos-Casals, Manuel; Brito-Zerón, Pilar; Seror, Raphaèle; Bootsma, Hendrika; Bowman, Simon J; Dörner, Thomas; Gottenberg, Jacques-Eric; Mariette, Xavier; Theander, Elke; Bombardieri, Stefano; De Vita, Salvatore; Mandl, Thomas; Ng, Wan-Fai; Kruize, Aike; Tzioufas, Athanasios; Vitali, Claudio


    To reach a European consensus on the definition and characterization of the main organ-specific extraglandular manifestations in primary SS. The EULAR-SS Task Force Group steering committee agreed to approach SS-related systemic involvement according to the EULAR SS Disease Activity Index (ESSDAI) classification and proposed the preparation of four separate manuscripts: articular, cutaneous, pulmonary and renal ESSDAI involvement; muscular, peripheral nervous system, CNS and haematological ESSDAI involvement; organs not included in the ESSDAI classification; and lymphoproliferative disease. Currently available evidence was obtained by a systematic literature review focused on SS-related systemic features. The following information was summarized for articular, cutaneous, pulmonary and renal involvement: a clear, consensual definition of the clinical feature, a brief epidemiological description including an estimate of the prevalence reported in the main clinical series and a brief list of the key clinical and diagnostic features that could help physicians clearly identify these features. Unfortunately we found that the body of evidence relied predominantly on information retrieved from individual cases, and the scientific information provided was heterogeneous. The analysis of types of involvement was biased due to the unbalanced reporting of severe cases over non-severe cases, although the main sources of bias were the heterogeneous definitions of organ involvement (or even the lack of definition in some studies) and the heterogeneous diagnostic approach used in studies to investigate involvment of each organ. The proposals included in this article are a first step to developing an optimal diagnostic approach to systemic involvement in primary SS and may pave the way for further development of evidence-based diagnostic and therapeutic guidelines. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights

  9. How mantle slabs drive plate tectonics.

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina


    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  10. Magnetostrictive direct drive motors

    Naik, Dipak; Dehoff, P. H.


    A new rare earth alloy, Terfenol-D, combines low frequency operation and extremely high energy density with high magnetostriction. Its material properties make it suitable as a drive element for actuators requiring high output torque. The high strains, the high forces and the high controllability of Terfenol alloys provide a powerful and challenging basis for new ways to generate motion in actuators. Two prototypes of motors using Terfenol-D rods were developed at NASA Goddard. The basic principles of operation are provided of the motor along with other relevant details. A conceptual design of a torque limiting safety clutch/brake under development is illustrated. Also, preliminary design drawings of a linear actuator using Terfenol-D is shown.

  11. Turbulent current drive

    Garbet, X.; Esteve, D.; Sarazin, Y.; Dif-Pradalier, G.; Ghendrih, P.; Grandgirard, V.; Latu, G.; Smolyakov, A.


    The Ohm's law is modified when turbulent processes are accounted for. Besides an hyper-resistivity, already well known, pinch terms appear in the electron momentum flux. Moreover it appears that turbulence is responsible for a source term in the Ohm's law, called here turbulent current drive. Two terms contribute to this source. The first term is a residual stress in the momentum flux, while the second contribution is an electro-motive force. A non zero average parallel wave number is needed to get a finite source term. Hence a symmetry breaking mechanism must be invoked, as for ion momentum transport. E × B shear flows and turbulence intensity gradients are shown to provide similar contributions. Moreover this source term has to compete with the collision friction term (resistivity). The effect is found to be significant for a large scale turbulence in spite of an unfavorable scaling with the ratio of the electron to ion mass. Turbulent current drive appears to be a weak effect in the plasma core, but could be substantial in the plasma edge where it may produce up to 10 % of the local current density.

  12. Multi-propeller drive system

    Belenger, Robert V.


    A multipropeller drive system having a single input shaft for connection to an engine system, a differential gear assembly for dividing the driving force from the input drive shaft between a pair of output shafts, and a pair of laterally spaced propellers driven by the output shafts of the differential gear assembly is disclosed. The differential gear assembly operates in a manner wherein one output shaft, if required, is permitted to revolve at a different rate than the other output shaft. A pair of brake mechanisms acting on the output shafts of the differential gear assembly enable an operator to control the rotational speed of the respective propellers without modifying the engine speed or transmission settings.

  13. High Amplitude Secondary Mass Drive



    In this paper we describe a high amplitude electrostatic drive for surface micromachined mechanical oscillators that may be suitable for vibratory gyroscopes. It is an advanced design of a previously reported dual mass oscillator (Dyck, et. al., 1999). The structure is a 2 degree-of-freedom, parallel-plate driven motion amplifier, termed the secondary mass drive oscillator (SMD oscillator). During each cycle the device contacts the drive plates, generating large electrostatic forces. Peak-to-peak amplitudes of 54 {micro}m have been obtained by operating the structure in air with an applied voltage of 11 V. We describe the structure, present the analysis and design equations, and show recent results that have been obtained, including frequency response data, power dissipation, and out-of- plane motion.

  14. Current Drive in a Ponderomotive Potential with Sign Reversal

    N.J. Fisch; J.M. Rax; I.Y. Dodin


    Noninductive current drive can be accomplished through ponderomotive forces with high efficiency when the potential changes sign over the interaction region. The effect can practiced upon both ions and electrons. The current drive efficiencies, in principle, might be higher than those possible with conventional radio-frequency current-drive techniques, since different considerations come into play.

  15. Current Drive in a Ponderomotive Potential with Sign Reversal

    Fisch, N J; Rax, J M


    Noninductive current drive can be accomplished through ponderomotive forces with high efficiency when the potential changes sign over the interaction region. The effect can practiced upon both ions and electrons. The current drive efficiencies, in principle, might be higher than those possible with conventional radio-frequency current-drive techniques, since different considerations come into play.

  16. Efficient Driving of Piezoelectric Transducers Using a Biaxial Driving Technique.

    Samuel Pichardo

    Full Text Available Efficient driving of piezoelectric materials is desirable when operating transducers for biomedical applications such as high intensity focused ultrasound (HIFU or ultrasound imaging. More efficient operation reduces the electric power required to produce the desired bioeffect or contrast. Our preliminary work [Cole et al. Journal of Physics: Condensed Matter. 2014;26(13:135901.] suggested that driving transducers by applying orthogonal electric fields can significantly reduce the coercivity that opposes ferroelectric switching. We present here the experimental validation of this biaxial driving technique using piezoelectric ceramics typically used in HIFU. A set of narrow-band transducers was fabricated with two sets of electrodes placed in an orthogonal configuration (following the propagation and the lateral mode. The geometry of the ceramic was chosen to have a resonance frequency similar for the propagation and the lateral mode. The average (± s.d. resonance frequency of the samples was 465.1 (± 1.5 kHz. Experiments were conducted in which each pair of electrodes was driven independently and measurements of effective acoustic power were obtained using the radiation force method. The efficiency (acoustic/electric power of the biaxial driving method was compared to the results obtained when driving the ceramic using electrodes placed only in the pole direction. Our results indicate that the biaxial method increases efficiency from 50% to 125% relative to the using a single electric field.

  17. Opportunities and Cooperation Drive Prosperity


    The old industrial base is lying in Northeast China. Although boasting many advantages such as talents, resources, transportation, environment, the region still have many disadvantages that needs opening up and reform. Revitalizing the Northeast region is an important task for China to built well-off society in an all-round way in the new century. It is also a big strategy made after developing costal region and western region by Chinese leaders according to current situation, which is a driving force

  18. 基于利益相关者理论的企业环境绩效影响因素研究%The Driving Force of Improving Coroparate Environmental Performance Based on the Stakeholder Theory

    刘蓓蓓; 俞钦钦; 毕军; 张炳; 张永亮


    基于利益相关者理论,通过构建企业环境绩效与企业受到各利益相关者环境压力的计量模型,并在江苏常熟地区展开问卷调查,分析了影响企业环境绩效的利益相关者,结果表明:在该实证区域,以主动性环境管理行为度量企业环境绩效时,投资者、竞争者、消费者和社区居民等外部利益相关者对企业环境绩效的提高有显著的正影响;政府虽然给企业造成了很高的环境压力,但并不是造成企业之间环境绩效差异的原因;媒体和环保非政府组织等外部利益相关者作用尚不明显.结论说明:我国政府通过引入利益相关者参与企业环境治理,已经取得一定成效.建议我国政府继续推动环境政策创新,积极创造更多利益相关者成长的制度空间,为我国企业环境绩效的提高提供更多动力.%Based on the stakeholder theory, this study established an econometric model to identify the key external stakeholders that may play a role in engaging enterprises to take environmental management initiatives, and tested the hypothesis by questionnaire in Changshu city. The results indicate that investors, consumers, competitors, and local community have positive significant effects in improving corporate environmental management. Though pressure from the government is relatively high, it does not implicate positive effect on corporate environmental performance. The role of media, environmental NGOs are not significant, either. Conclusions implicate that the Chinese government has made some improvements through inducing various stakeholders to participate in corpoarate environmental governance. Suggustions are that Chinese government should keep on promoting policy innovation, exploring more institutional space for more stakeholders and providing new driving force for the improvement of corporate environmental management.

  19. Analysis on driving force of Chinese airline network connecting based on gravity mode%基于重力模型的中国航空网络航线连接驱动力分析

    曾小舟; 江可申; 董莉莉


    航空网络的航线旅客流量,决定了机场间航线的连接.因此,引起OD流生成的经济社会因素就是航线连接的驱动力.依据重力模型的原理,先选择影响航线OD流量的机场城市经济社会因素,再通过灰色聚类方法,确定出了机场城市的第三产业产值、人均可支配收入和城镇人口是影响OD流量的根本因素;然后分别以这三个因子作为网络优先连接驱动因素,构建与中国实际航空网络规模相当的仿真网络,通过仿真网络和真实网络度值分布曲线对比,发现第三产业对航线连接驱动力最大,其次是人均可支配收入.%The flow of aviation network' s airline passenger, determines the connections of airport airline. The social factors of economic what lead to OD flow are the driving forces of connections of airline. This paper selected the social factors of economic what affect airline OD flow of airport city based on the principles of gravity model, and through the grey clustering method, determined that urban per capita disposable income out of the airport, the town population and the city' s tertiary industry output were fundamental factors affecting OD flow; it took the three factors as priority network drivers connection individually, construct and practice simulation network what like China aviation network fairly, through the comparison of value distribution curve of simulation and real networks ,and found what affect routes connecting most was the tertiary industry, the followed was the average per capita disposable income.

  20. Characteristics of grassland degradation and driving forces in the source region of the Yellow River from 1985 to 2000%黄河源地区草地退化空间特征

    刘林山; 张镱锂; 摆万奇


    The source region of the Yellow River is located in the middle east of the Tibetan Plateau in northwest China. The total area is about 51,700 km2, mainly covered by grassland (79%), unused land (16%) and water (4%). The increasing land utilization in this area has increased the risk of environmental degradation. The land use/cover data (1985 and 2000) provided by the Data Center of Resources and Environment in the Chinese Academy of Sciences were used to analyze the land cover change in the source region of the Yellow River. DEM (1:250,000) data, roads and settlement data were used to analyze the spatial characteristics of grasslands degradation. The ArcGIS 9 software was used to convert data types and do the overlay, reclassification and zonal statistic analysis. Results show that grassland degradation is the most important land cover change in the study area, which occupied 8.24% of the region's total area. Human activities are the main causes of the grassland degradation in the source region of the Yellow River: 1) the degradation rate is higher on the sunny slope than on the shady slope; 2) the grassland degradation rate decreases with an increase in the elevation, and it has a correlation coefficient of -0.93; 3) the nearer to the settlements the grassland is, the higher the degradation rate. Especially within a distance range of 12 km to the settlements, the grassland degradation rate is highly related with the distance, with a coefficient of -0.99; and 4) in the range of 4 km, the degradation rate decreases with the increase of distance to the roads, with a correlation coefficient of -0.98. Besides some physical factors,human activities have been the most important driving forces of the grassland degradation in the source region of the Yellow River since 1985. To resolve the degradation problems, population control is essential, and therefore, it can reduce the social demand of livestock products from the grassland. To achieve sustainable development, it

  1. The Driving Forces of Tourism Eco-Efficiency in the Context of Low Carbon%低碳背景下旅游业生态效率驱动机制研究



    Tourism eco-efficiency is a very important indicator assessing both environmental and economic effect at the same time,and will ensure the sustainable development of tourism. The eco-efficiency of six sectors of tourist industry and its driving forces were analyzed in Henan Province during 1995-2013. The empirical coefficient method and vector autoregression(VAR)model were employed. The resulted indicated that the eco-efficiencies of tourism accommodation and transportation were lower than the average of the whole tourist industry ,whereas they would tend to be better over time. However,the eco-efficiencies of tourism catering,traveling,shopping and entertainment were higher than the average of the whole tourist industry,whereas they would tend to be worse over time. The impulse response function showed that the responses of eco-efficiency value to the impulses of energy intensity and proportion of tourism transportation output were negative as a whole,whereas the response to the consumption of per tourist was positive. Variance decomposition showed that the consumption of per tourist had greater contribution to eco-efficiency that the other two influencing factors.%以河南省为例,基于碳排放视角核算了1995—2013年间河南省旅游业6大部门的生态效率,用VAR模型分析了旅游生态效率对影响因素的动态响应。结果显示:旅游住宿和交通的生态效率较低,但发展趋势向好;旅游餐饮、游览、购物和娱乐4个部门的生态效率较高,但发展趋势堪忧;旅游业整体的生态效率缓慢提高。脉冲响应分析和方差分解分析表明人均旅游产出是导致旅游生态效率降低的主要因素,能源强度和旅游交通产出占比对旅游业经济产出的影响大于对旅游碳排放的影响,长期来看有助于提高旅游生态效率。

  2. Offset Compound Gear Drive

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.


    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.


    Piotr FOLĘGA


    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  4. UV laser ablation to measure cell and tissue-generated forces in the zebrafish embryo in vivo and ex vivo.

    Smutny, Michael; Behrndt, Martin; Campinho, Pedro; Ruprecht, Verena; Heisenberg, Carl-Philipp


    Mechanically coupled cells can generate forces driving cell and tissue morphogenesis during development. Visualization and measuring of these forces is of major importance to better understand the complexity of the biomechanic processes that shape cells and tissues. Here, we describe how UV laser ablation can be utilized to quantitatively assess mechanical tension in different tissues of the developing zebrafish and in cultures of primary germ layer progenitor cells ex vivo.

  5. Analysis of Vehicle Steering and Driving Bifurcation Characteristics

    Xianbin Wang


    Full Text Available The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

  6. Artificial surfaces in the Raya Central Iberica Use generalized linear models to define driving forces of the territorial changes; Las superficies artificiales en la Raya Central Iberica El uso de modelos lineales generalizados para definir los factores condicionantes de los cambios territoriales

    Jaraiz Cabanillas, F. J.; Mora Aliseda, J.; Gutierrez Gallego, J. A.


    The rapid changes that the socio-demographic structure and the economic activity are experiencing in the Raya Central Iberica, and that are produced for the new socioeconomic needs, the concentration of the population in the principal cities, the abandon of the rural spaces, the growth of irrigation areas, etc., they motivate changes in the artificial surfaces. A spatial analysis is applied to determine the principal driving forces of the artificial surfaces changes. For this, different tools are in use in order to differentiate the land use and land cover changes or the driving forces. The changes were quantified by statistical technologies and images of CORINE Land Cover Project and the driving factors were analyzed by logistic regressions (generalized linear models) combining human and geophysics variables. Conclusions show the suitability of the employment of the information of CORINE Land Cover project, the significant selected independent variables, and the validity of the generalized linear models for the explanation of the land use and land cover change of a certain territory. (Author)


    王金亮; 蒋莲芳; 李瑞林


    counties that prefectures located (such as Shangri-la, Lushui and Lijiang) was faster than of that othercounties. (5) The main driving forces of LUCC of this area were social-economy factors, including population growth,science technology development, growth of economy, inheritance and development of ethnic cultures, changes of policy and laws related to resources use and environmental protection.

  8. 新媒体:开启文化艺术市场新纪元的驱动力%New Media:the Driving Force Which Opens a New Era of Culture and Art Market



    在传媒革命中,互联网及其衍生的各种新媒体形式不仅影响我们观看和体验世界的方式,改变我们的交流、沟通习惯,增加各种传播形式的社会、文化功能,还强烈冲击着以信息技术和知识经济为基础的文化艺术市场体系。新媒体不但为文化艺术产品提供了“融合性”展示新平台,为文化艺术品客户提供“互动性”消费新体验,还开拓了文化艺术市场的“个性化”新领域,从而成为创新驱动力,推动创意与内容产业不断扩展,为世界经济模式和文化艺术市场增添了新的维度和内容,在技术变革的同时,改变了文化产业的基本面貌,促使文化艺术市场的经济模式与营销价值链的转化与更新,开启了文化艺术市场的新纪元。%With the revolution of the media,Internet and a variety of new media forms derived from it not on-ly affect our ways of viewing and experiencing the world,change the habits we talk and communicate,in-crease various social and cultural functions of communication forms,but also have a strong impact on the culture and art market system which is based on the information technology and knowledge economy.New media provides a new integrated presentation platform for cultural and artistic products,the new interactive consumption experience for consumers of cultural and artistic products,and it opens new personalized areas for Culture and art market,thus becomes the driving force of innovation,promotes the expansion of creativity and content industry continually and adding new dimension and content to the world economy and culture and art market.Accompanyed with the technological revolution,the new media innovates and creates the basic profile of cultural industries,promotes the transformation and renewal of the economical mode and marketing value chain in culture and art market,and opens a new era of culture and art market.

  9. Dynamic change and driving forces of cultivated land use in Sangong River Basin in recent 60 yeas%近60a三工河流域耕地利用动态变化与驱动力分析

    唐宏; 张新焕; 杨德刚; 陈大波


    As a typical area of Mountainous - Oasis - Desert System in arid zone, where the ecological environment is fragile and sensitive, Sangong River Basin has a strong regional differences in land use. Study on the spatio-temporal variation and its driving forces of cultivated land use in Sangong River Basin, and analyzing the relationship between cultivated land use and natural conditions and socio-economic development, is of great benefit to use the cultivated land reasonably, optimization land use structure, guarantee safety of grain production and ecological, and Provide recommendations for policy formulation. Based on the data of cultivated land use in 1949 -2008, the article analyzes the dynamic changes of cultivated land use in Sangong River Basin from land size, land structure and land use efficiency. Regression model was applied to analyze the change of population size and land size, and gray relative analysis was applied to analyze relationship between cultivated land use efficiency and their impact factors. The results show as follows: (1) the cultivated land area of Sangong River Basin tends to increase, and the trend is varied in different stages, but the per capita cultivated land area tends to decline. The variation trend of crop planting structure is consistent with that of Xinjiang, which changes from grain-based to common development of food crops and cash crops. Crop yield per unit area tends to increase, where the yield per unit area of grain crops and oil bearing crops are higher than the average level of Xinjiang, yield of beetroots has greater fluctuations, and yield per unit area of cotton is much lower than Xinjiang. Value of output per unit area grows continued, the relative index of which fluctuates seriously, and the benefit of cultivated land use is lower than the average level of Xinjiang. ( 2 ) Population growth and the increased demand for food with it are the basic reason which led to the increasing of cultivated land, but considered the

  10. 黑河中游土地利用/覆盖变化及主导因素驱动力%Land use/cover changes and main-factor driving force in Heihe middle reaches

    曹琦; 陈兴鹏; 师满江; 姚勇


    . Due to the effect of the restriction of the special natural conditions, resources and the environment system in a continental river basin in an arid zone are especially affected by anthropogenic influences. Some scholars pointed out that, if the effective strength of human activities exceeds 37%, the river surface runoff process shits from its natural state to giving priority to an anthropogenic disturbance, Therefore, affecting the middle and lower reaches of the oasis area size would directly impact on the process of the middle reaches of land -use and land-cover change. In order to understand the current problem of the land, we needed to identify the key human influencing factors, discuss its regulatory mechanism, and evaluate its effect on land-use and land-cover change, on basis of which we sought countermeasures to solve the problem. There are many attempts at related research on an anthropogenic driving effect on land -use and land-cover change by quantitative analysis. However, the anthropogenic influence during the course of basin scale land change has not been extensively researched. In order to investigate the driving effect by anthropogenic influence on land use and land cover change in the Heihe Middle Reaches, this paper took Ganzhou District as an example. First, this article analyzed the velocity and amplitude of various land use types and a comprehensive index of LUCC in the study area under anthropogenic influence from the year 2002 to 2011. Secondly, based on specifying the trend of various types of land use change, this article established a humanistic factors index system, and simulated multiple linear relationships between humanities factors and LUCC. Finally, it extracted key humanity factors that affected different land use types through Grey Relational Analysis. The results of the analysis were as follows:1) In the overall structure of land use/cover of the Ganzhou area from 2002 to 2011, construction land expanded at an accelerating pace

  11. Friction and Wear in Timing Belt Drives

    B. Stojanovic


    Full Text Available Timing belt tooth goes into contact with a drive pulley, stretched to the maximum, because of the previous tension. When the contact begins the peak of the belt tooth makes the contact with the outer surface of the pulley teeth. The process of the teeth entering into the contact zone is accompanied with the relative sliding of their side surfaces and appropriate friction force. The normal force value is changing with the parabolic function, which also leads to the changes of the friction force. The biggest value of the normal force and of the friction force is at the tooth root. Hollow between teeth and the tip of the pulley teeth are also in contact. Occasionally, the face surface of the belt and the flange are also in contact. The friction occurs in those tribomechanical systems, also. Values of these friction forces are lower compared with the friction force, which occurs at the teeth root.

  12. Driving After a Stroke

    ... Inspirational Stories Stroke Heroes Among Us Driving After Stroke Updated:Jul 23,2015 Can I drive after ... more tips for daily living . Let's Talk About Stroke Fact Sheets Our stroke fact sheets cover treatments, ...

  13. Electric Vehicle - Economical driving

    Jensen, VCE, Steen V.; Schøn, Henriette


    Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading.......Instruct the reader in getting most satisfaction out of an EV, especially concerning driving and loading....

  14. Dementia and driving

    ... this page: // Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  15. Gear bearing drive

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)


    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  16. Combination spindle-drive system for high precision machining

    Gerth, Howard L.


    A combination spindle-drive is provided for fabrication of optical quality surface finishes. Both the spindle-and-drive utilize the spindle bearings for support, thereby removing the conventional drive-means bearings as a source of vibration. An airbearing spindle is modified to carry at the drive end a highly conductive cup-shaped rotor which is aligned with a stationary stator to produce torque in the cup-shaped rotor through the reaction of eddy currents induced in the rotor. This arrangement eliminates magnetic attraction forces and all force is in the form of torque on the cup-shaped rotor.

  17. Force Modulator System

    Redmond Clark


    Many metal parts manufacturers use large metal presses to shape sheet metal into finished products like car body parts, jet wing and fuselage surfaces, etc. These metal presses take sheet metal and - with enormous force - reshape the metal into a fully formed part in a manner of seconds. Although highly efficient, the forces involved in forming metal parts also damage the press itself, limit the metals used in part production, slow press operations and, when not properly controlled, cause the manufacture of large volumes of defective metal parts. To date, the metal-forming industry has not been able to develop a metal-holding technology that allows full control of press forces during the part forming process. This is of particular importance in the automotive lightweighting efforts under way in the US automotive manufacturing marketplace. Metalforming Controls Technology Inc. (MC2) has developed a patented press control system called the Force Modulator that has the ability to control these press forces, allowing a breakthrough in stamping process control. The technology includes a series of hydraulic cylinders that provide controlled tonnage at all points in the forming process. At the same time, the unique cylinder design allows for the generation of very high levels of clamping forces (very high tonnages) in very small spaces; a requirement for forming medium and large panels out of HSS and AHSS. Successful production application of these systems testing at multiple stamping operations - including Ford and Chrysler - has validated the capabilities and economic benefits of the system. Although this technology has been adopted in a number of stamping operations, one of the primary barriers to faster adoption and application of this technology in HSS projects is system cost. The cost issue has surfaced because the systems currently in use are built for each individual die as a custom application, thus driving higher tooling costs. This project proposed to better

  18. Confusion around the tidal force and the centrifugal force

    Matsuda, Takuya; Boffin, Henri M J


    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  19. Simple Driving Techniques

    Rosendahl, Mads


    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data......Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp...

  20. High performance AC drives

    Ahmad, Mukhtar


    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  1. Analysis of desertification process and driving force factors in grassland ecosystem of Xinjiang%新疆草地荒漠化过程及驱动因素分析

    郑伟; 朱进忠


    desertification process was divided into 2 types. I type was the process of desertification, salinization and degradation of desert grassland in the zone of plain and low hill, and II type was the process of degradation in mountain grassland. (2) under the combined effect of human activities and the changes of hydrological environment on desertification, the grassland could transform into farmland, woodland, wetland, desert and community in the process of desertification. (3) the background of grassland desertification was the special topography, geomorphology, soil and climate. The natural factors provide the substance of desertification. The climate change was one of the main factors of desertification in the grassland of Southern Xinjiang and Eastern Xinjiang. (4) the unreasonable use of water resources was the main factor of desertification in the grassland of midstream and downstream. The reclamation and excavation grassland were the direct factors of desertification in the grassland around oasis. The long-term overgrazing and disorder grazing, low input of grassland management were the main factors of desertification in the pasture and mowing grassland. The driving force of grassland desertification has the characteristics of regionalism, multifactor and the desertification was the results of combined effect of natural factors and human activities.

  2. Remote sensing dynamic monitoring and driving force analysis of land use/cover changes in Qingchuan County%青川县LUCC遥感动态监测及驱动力分析

    刘萌; 杨武年; 邵怀勇; 孙小飞


    Qingchuan County of Guangyuan City in Sichuan Province is a national ecological pilot county and implementation country of returning farmland to forest. The understanding of the current situation and spatial -temporal dynamic change of land use/cover is of great significance in providing the scientific basis for relevant government departments. In this paper, with the application of RS and GIS technology, on the basis of TM images in 2000, 2005 and 2010, and through image processing and information extracting, the authors acquired land use/cover maps in different years and established the database. On such a basis, the land use/cover dynamic change process in Qingchuan in the past 10 years was analyzed, and the driving force that caused the change was identified. At last, land use/cover area ratio of the study area in 2015 and 2020 were predicted. According to the results obtained, between 2000 and 2005, the area of arable land, water and unused land decreased, while the area of woodland, grassland and construction land increased;between 2015 and 2020, the area of arable land and grassland decreased, while the area of woodland, water, construction land and unused land increased. During the ten years, the area of arable land continually decreased with the scale reduced, the area of woodland continually increased with the scale reduced, the area of construction land increased continually with the scale increased, the area of water and unused land decreased and then increased, and the area of grassland increased and then decreased. An analyses reveals that policy, economic development, population growth, and natural disasters seem to be the principal impact factors of land use changes in the study area. It is inferred that, under the conditions that relevant policy is unchanged and no natural disasters occur, the proportion of woodland area will increase from 58. 57% in 2010 to 59 . 01% in 2015 , and increase to 59 . 44% in 2020 . The proportion of arable area will

  3. 基于ANN-CA的银川平原湿地景观演化驱动力情景模拟分析%The Scenarios Simulation Analysis of Driving Forces of Wetland Landscape Evolution Using ANN-CA in Yinchuan Plain

    张美美; 张荣群; 郝晋珉; 艾东


    Wetland landscape spatio-temporal dynamic development process is more important than the ultimate form of its spatial pattern. Only clearly understand wetland dynamic development process, the theory and deci-sion support of wetland resources protection and sustainable utilization can be provided. In this paper, Yinchuan Plain wetland landscape evolution driving force analysis model was established, full considering the causal rela-tionship between the geographical phenomena in space and time. The transform rules of cellular automata (CA) were built with the model of artificial neural network (ANN), which reduced the man-made subjective factors, and improved the accuracy. Comparing the prediction results with actual wetland types, it concludes that the pre-diction accuracy reaches about 84.24%. Three driving force factors as annual precipitation, population density and agriculture gross output value were selected for the scenarios simulation of wetland landscape pattern. The scenarios simulation results show that, average annual rainfall has more significant driving force to natural wet-land, in the process of reduced by 10%to increased by 10%, the area of river and lake wetlands continues to in-crease, with river wetland increased 26.3844 km² and lake wetland 22.4100km². Rice paddies and ponds main-tain a steady growth. Population density has more significant driving force to artificial wetland. With the growth rate of population density changing from 8‰to 18.7‰, rice paddies and ponds expanded greatly, i.e. 19.4364 km² and 18.2088 km², respectively. But the area of natural wetlands (river and lake wetlands) decreased gradual-ly, and the construction land increased markedly. Total agricultural output also has more significant driving force to artificial wetlands, but slow reverse inhibition force to natural wetlands. When the growth rate of total agricul-tural output changes from 4.5%to 6.5%, artificial wetlands such as rice paddies and ponds expand rapidly

  4. Polymorphic coupling vibration of a mill main drive system induced by synergy effect of motor current harmonics and rolling force ones%电流谐波与轧制力谐波协同诱发主传动多态耦合振动研究

    张义方; 闫晓强; 凌启辉


    现代大型热连轧机是一种复杂机电系统,轧机振动问题是影响轧机生产稳定的严重问题。利用扭矩遥测系统测试轧机机械传动系统扭振发现轧机主传动扭振波形及频谱中存在典型的强或弱两种振动特征。同时发现轧机在轧制过程中电机电流和轧制力存在谐波,当谐波与传动系统固有频率接近时将诱发较大的振动。为研究其机理,利用仿真技术求解了轧机主传动扭振与电流谐波和轧制力谐波激励的相关性。研究表明:随着谐波激励特征的变化,主传动扭振呈现多态强弱变化,从而为抑制轧机耦合振动提供理论依据。%Large modern hot strip mill is a complex electromechanical system.Vibration of a rolling mill is a serious problem affecting the stability of production.By using a torque telemetry system to measure the torsional vibration of the main mechanical drive system,it was shown that two typical characteristics of strong or weak vibration exist in the waveform and spectrum of the torsional vibration;meanwhile,there are harmonics of motor current and rolling force during the rolling mill’s production;when the harmonic frequencies are close to the natural frequencies of the main drive system, heavier torsional vibrations are induced in the mill main drive system.For the study of their mechanism,using computer simulation,the correlation between the main drive system torsional vibration and the harmonic excitations of motor current and rolling force was solved.The study results showed that with the changes in harmonics excitations,the torsional vibration of the main drive system reveals a polymorphic strong or weak variation.The results provided a theoretical foundation for suppressing rolling mills’coupling vibration.

  5. Accelerating the Transformation of Public Expenditure to Enhance the Consumption Driving Force of the Economic Growth in Jiangsu%加快推进公共支出转型增强江苏经济增长消费驱动力

    刘东皇; 孟范昆


      投资和出口在江苏经济增长过程中扮演着特别重要角色,而消费对经济增长的驱动作用在持续下降。作为影响居民消费的重要因素,江苏的公共支出并未对城乡居民消费产生挤入效应。江苏公共支出转型总体上符合经济发展方式转变的要求,但也存在相关的问题。因此,应加快推进公共支出转型,增强江苏经济增长的消费驱动力。%  Investment and export played a very important role in Jiangsu′s economic growth process , but consumption driving force is declining .Public expenditure is an important factor affecting consumption , but it does not produce crow-ding-in effect on consumption of urban and rural residents in Jiangsu .Overall the transformation of public expenditure in Jiangsu is in line with the requirements of the economic development pattern , but there are related problems .There-fore, we should accelerate the transformation of public expenditure to enhance the consumption driving force of the eco -nomic growth in Jiangsu .

  6. 力基准机独立连续加码装置的设计%Design of Loading Weights Respectively and Continuously Device on the Primary Force Standard Machine

    康博; 张伟; 陈守强; 张弘


    静重式力基准机在加卸砝码时存在加载力值组合少、冲击大、精度低等问题.为此,分析并提出了力基准机独立连续加码的加卸砝码方式,设计了实现这种方式的机械结构.采用机械弹性系统,减小了整个系统的冲击.设计浮动升降托架,使得整个系统能够实现机械自适应.%It had some defects such as less weights combined, greater force impact and lower accuracy when loading weights and uninstalling weights on the traditional primary force standard machine. Therefore, the manner of loading weights respectively and continuously on the primary force standard machine was analyzed and put forward, and the mechanical structure to achieve this manner was designed. The impact on the whole system was reduced by the machine using mechanical flexibility system. At one time, by designed the floating up-down bracket, the adaptive machine can be achieved on the whole system.

  7. 农村居民点用地发展变化驱动力研究——以鹿泉市为例%Driving Force of Rural Residential Land Change Research——A Case of Luquan County

    陈利东; 黄志英; 李珊; 史兴兴; 闫妍; 刘云亮


    This article from the perspective of geography based on Luquan County status in the analysis of problems of rural settlements, The rural residential area of the driving factors summarized as changes in economic, demographic, technological, policy, social five. Quantitative measure of the driving factors to establish the impact of multivariate linear model, and used path analysis to explore drivers of change and rural residential area of the relationship between the various driving factors as well as the relationship between the main conclusions are: economic factors, demographic factors and policy factors on changes in the rural settlements have a greater impact, which, by technical factors and social factors on the impact of economic and demographic factors to reflect its rural residential area of change.%在分析鹿泉市现状农村居民点存在问题的基础上,从地理学的角度入手,将农村居民点变化的驱动因子归纳为经济、人口、技术、政策、社会5个方面,得到定量度量各驱动因子影响的多元线性模型,并用路径分析方法探讨驱动因子与农村居民点面积变化以及各驱动因子之间的关系.研究结果表明:经济因子、人口因子和政策因子对农村居民点变化均有较大影响,其中,技术因子和社会因子对农村居民点发展变化的影响是通过经济和人口因子来体现的.

  8. Water Level Variations of Yamzho Yumco Lake in Tibet and the Main Driving Forces%1974-2009年西藏羊卓雍错湖泊水位变化分析

    除多; 普穷; 旺堆; 米玛次仁; 拉巴卓玛; 张雪芹; 孙瑞


    the mean annual water level and the rest is lower than the mean annual water level. The lowest ntonthly water level is in Jun and the highest value is in October. There is two - month time lag between the highest monthly water level and precipitation. Water level changes of the lake are mainly caused by precipitation fluctuation. Temperature is dedicated to water level changes through glaciers and snow melting within the basin under continuous increase in temperature. There is a negative correlation between evaporation and water level variations, which means that higher evaporation leads to decrease in water level of the lake. Particularly, the fluctuation of inter-annual precipitation is the main driving forces for water level variations. The impact of human activity and the engineering measures such power plant construction on the water level variation is limited. Yamzho Yumco Pumped Storage Power Station has been in operation in 1998 and the basin environment ameliorates under background of warm and humid climate and its impact on water level variations are limited. The design goal of the power plant is that during summer the water is pumped from Yarlung Zangbo River to the lake using extra power and in other seasons the power station generates power. However, if the water between lake and river can not keep in balance and meet the design goal of the power station, the impact of the power station on water level variations can not be ignored.

  9. Lectures on magnetohydrodynamical drives

    Loigom, Villem

    The paper deals with nonconventional types of electrical machines and drives - magnetohydrodynamical (MHD) machines and drives. In cardinal it is based on the research conducted with participation of the author in Tallinn Technical University at the Institute of Electrical Drives and Power Electronics, where the use of magnetohydrodynamical motors and drives in the metallurgical and casting industries have been studied for a long time. Major research interests include the qualities and applications of the induction MHD-drives for set in the motion (pumping, turning, dosing, mixing, etc.) non-ferrous molten metals like Al, Mg, Sn, Pb, Na, K, and their alloys. The first part of the paper describes induction MHD motors and their electrohydraulical qualities. In the second part energy conversion problems are described. Also, on the basis of the analogy between electromechanical and electrohydraulical phenomenas, static and dynamic qualities of MHD drives with induction MHD machines are discussed.

  10. Universal Drive Train Facility

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  11. Validation Test of CARR Safety Rod Driving Mechanism


    <正>CARR safety Rods are driven by hydraulic force. The safety rod driving mechanism is designed by Tsinghua University and manufactured by Shenyang LIMING factory. Two sets of the mechanism are used for the validation test.

  12. 基于Logistic回归模型的北京市水库湿地演变驱动力分析%Driving Forces Analysis of Reservoir Wetland Evolution in Beijing Based on Logistic Regression Model

    李洪; 宫兆宁; 赵文吉; 宫辉力


    The reservoir wetland of Beijing, constitutes one of the important eco-systems in Beijing. The driving factors index system of Beijing reservoir wetland landscape evolution in the study area was built in the two aspects of the natural environment and socio-economy. Natural driving factors include precipitation, temperature, entry water and groundwater depth; social economic driving factors include the resident population, urbanization rate and per capita GDP. Using TM images from 1984 to 2010 to extract reservoir wetland's spatial distribution information of Beijing, we analyzed the area of reservoir wetland change laws in nearly 30 years. The driving mechanism of reservoir wetland evolution in the study area was explored by the Logistic regression model in different periods. The results indicated that in different phases, the driving factors and their influence on reservoir wetland evolution had certain differences. During 1984-1998, the leading driving factors were annual average precipitation and entry water index with the contribution rate of Logistic regression being 5.78 and 3.50, respectively, which was mainly affected by natural environmental factors; from 1998 to 2004, the impact of human activities intensified and man-made reservoir wetland reduced, and the main driving factors were the number of residents, groundwater depth and urbanization rate with the contribution rate of Logistic regression 9.41, 9.18, and 7.77, respectively. During 2004-2010, reservoir wetland evolution was impacted by both natural and socio-economic factors, and the dominant driving factors were urbanization rate and precipitation with the contribution rate of 6.62 and 4.22, respectively.%水库湿地作为北京市面积最大的人工湿地,是北京市重要的生态基础设施.从自然环境和社会经济因素两个方面,构建北京市水库湿地演变的驱动因子指标体系,其中自然驱动因子包括年均降水量、气温、入境水量和地下水埋深;


    张孝宇; 赖宗裕; 张安录


    empirical evidences showing that effects of driving forces of farmland conversion are actually different in space.Theoretically,locations of farmland are relatively fixed while effort of driving forces is non-stationary in space,which would cause spatial heterogeneous of driving forces of farmland conversion.In this paper,we established two models to evaluate driving forces of farmland conversion and the spatial heterogeneous of driving forces.We used logistic regression model firstly and then geographically weighted logistic regression model.Then the prediction accuracy of the two models were compared.We took Wuhan as a typical city and used the land use data and GIS data of public facilities,environmental and economics from 2000 to 2011 based on patch scale.Based on the analysis,the main conclusions are as follows.Firstly,based on the estimation results of the logistic regression models,spatial dependence between farmland and spatial spillover of construction land to farmland had a significant effects on the probability of farmland conversion,which indicates that farmland conversion presened probably local rather than global.Based on the estimation results of the geographically weighted logistic regression model,environment and public facilities,characteristics of social and economic and land use policy had different effects on the probability of farmland conversion in space,but there was no difference in the directivity.Both estimation results of the two models show that driving forces of farmland conversion performed spatial heterogeneous.Secondly,geographically weighted logistic regression model was better fitting and better predictive accuracy than logistic regression model.Because geographically weighted logistic regression model has a more realistic hypothesis as the model foundation.Geographically weighted logistic regression model could deal with patch scale data of farmland conversion while geographically weighted regression model could only deal with large scale


    Ion BOSTAN


    Full Text Available The paper presents the modelling and simulation of precessional drives designed in two variants capable of high transmission ratio and torque for one stage compact construction. The constructions were designed in Inventor and also as multi body systems in otionInventor. The simulations of the drives provide information concerning positions, velocities, accelerations, point trajectories, forces and moments, energies, as well as contact forces at the contact between gear teeth and satellite teeth and other data concerning the system.

  15. 基于迭代学习的直线伺服系统推力纹波辨识及补偿研究%Research on Parameter Identification and Compensation of Force Ripple in Linear Drive System based on Iterative Learning

    杨亮亮; 史伟民; 彭来湖


    Force ripple is a periodic disturbance which has a negative effect on high speed and high precision of linear drive system, this paper put forward a new method to identify parameters of force ripple disturbance and compensate the force ripple disturbance based on a known control structure and force ripple disturbance model which was established according to its periodic characteristic. This method establishes iterative learning rule and convergent characteristic of parameter identification algorithm according to an optimal performance function and compensates the force ripple disturbance by feedforward. Experimental results show that the iterative tuning method effectively enhances tracking and response performance and meets the high speed and high precision requirements.%具有周期性规律的推力纹波扰动是影响直线伺服系统的高速高精性能的重要原因之一,该文根据推力纹波扰动的周期性规律,在给出直线进给控制器结构及推力纹波数学模型的基础上提出一种基于迭代学习的推力纹波参数辨识及补偿的方法,该方法通过最优性能指标函数确定了迭代学习规律和收敛性,并通过前馈进行推力纹波补偿.实验结果表明该方法显著提高直线伺服系统的位置跟踪精度和高速响应性能,满足其高速高精的要求.

  16. Piezoelectric drive circuit

    Treu, Jr., Charles A.


    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  17. Fundamentals of electrical drives

    Veltman, André; De Doncker, Rik W


    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  18. Electric vehicles: Driving range

    Kempton, Willett


    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  19. Recognizing driving in haste

    Rendón-Vélez, E.


    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  20. Drive Around the World

    Yang Wei


    @@ "It's so cool that I can drive on my own,and my own car,"Cao Gang,WOrking for a private company in Changsha,capital city of Hunan Province,mid-south China,said in excitement when he newly bought Ben Ben,a Chinese local auto brand of Chang'an,with his freshly-passed driving license.

  1. Recognizing driving in haste

    Rendón-Vélez, E.


    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  2. Electric Vehicle - Economical driving

    Jensen, VCE, Steen V.; Schøn, Henriette


    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  3. Recognizing driving in haste

    Rendón-Vélez, E.


    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't

  4. Evaluation of the overweight/obese child--practical tips for the primary health care provider: recommendations from the Childhood Obesity Task Force of the European Association for the Study of Obesity

    Baker, Jennifer L; Farpour-Lambert, Nathalie J; Nowicka, Paulina


    in the primary care setting. The tips and tools provided are based on data from the recent body of work that has been published in this field, official statements of several scientific societies along with expert opinion provided by the members of the Childhood Obesity Task Force (COTF) of the European......The prevalence of obesity among children and adolescents is on the rise. The majority of overweight or obese children are treated by primary health care providers including paediatricians, family practitioners, dieticians, nurses, and school health services - and not by specialists. The majority...... of obese children have no underlying medical disorder causing their obesity yet a significant proportion might suffer from obesity-related co-morbidities. This text is aimed at providing simple and practical tools for the identification and management of children with or at risk of overweight and obesity...

  5. Evaluation of the overweight/obese child--practical tips for the primary health care provider: recommendations from the Childhood Obesity Task Force of the European Association for the Study of Obesity

    Baker, Jennifer L; Farpour-Lambert, Nathalie J; Nowicka, Paulina


    The prevalence of obesity among children and adolescents is on the rise. The majority of overweight or obese children are treated by primary health care providers including paediatricians, family practitioners, dieticians, nurses, and school health services - and not by specialists. The majority...... in the primary care setting. The tips and tools provided are based on data from the recent body of work that has been published in this field, official statements of several scientific societies along with expert opinion provided by the members of the Childhood Obesity Task Force (COTF) of the European...... Association for the Study of Obesity (EASO). We have attempted to use an evidence-based approach while allowing flexibility for the practicing clinician in domains where evidence is currently lacking and ensuring that treating the obese child involves the entire family as well....

  6. Study on Cultivated Land Resource Situation and Its Macro-Driving Forces in Yantai Area%烟台地区耕地资源态势及宏观驱动力研究



    According to the statistics of cultivated land in Yantai area during the Reform and Opening-up over the past 20years and with the detailed survey and changing data of land use during the recent five years, this paper reveals the basic characteristics of the resource utilization, the basic process of the changes, regional differences, and current direction of cultivated land. In addition, this paper makes a preliminary research on the major driving factors and the influence mechanism for the changes in the cultivated land area, and reaches the following conclusions: (1) There was a trend of obvious fluctuant decrease in cultivated land area during the past 20 years. The changes of cultivated land have undergone the process - slow decrease, steep decrease, slow decrease. And there were three peak periods of cultivated land loss around 1985, 1987-1990and 1991-1993 respectively. (2) The decreased cultivated land was mainly converted into land for industry and mining,residential area, and all kinds of traffic and orchards. The increase of cultivated land mainly came from exploitation and reclamation of non-utilized land and arrangement and reclamation of industry and mining land. (3) The economic development,population growth and policy are the dominant macro-driving factors for the decrease of cultivated land area in Yantai. The obvious sudden changes during the change process of cultivated land acreage are relevant to the national macro-policies background. The rapid decrease of cultivated land area is synchronous with the overheated economic growth resulting from the direct investment infixed assets. Spatial distribution of the decrease in cultivated land is congruous with the differences in speed and the scale of economic growth between the different regions of Yantai area. Furthermore, the decrease in cultivated land caused by population increase cannot be ignored.

  7. Effect of driving cycles on energy efficiency of electric vehicles

    JI FenZhu; XU LiCong; WU ZhiXin


    Based on several typical domestic and foreign driving cycles, the energy usage efficiency of the EVs-XL 2000 type electric vehicle (EV) is analyzed.The energy usage efficiency of EVs and the evaluation index of electromotor efficiency are studied.The concepts of "interval usage percentage of energy efficiency" and "exertion degree of energy efficiency" of electromotor are presented.The effects of driving cycles on the distribution of the running status of electromotor and the efficiency are investi-gated.The efficiency of electromotor and the trend of average driving force at different driving cycles are discussed.The exertion degree of energy efficiency and the total power train efficiency of the EVs-XL 2000 type electric vehicle at typical driving cycles are analyzed and calculated.The result in-dicates that the driving cycle engenders a big influence on the exertion degree of electromotor energy efficiency at different driving cycles.Dissimilar driving cycles result in different efficiency distributions of electromotor, the control system as well as the average driving force and driving range are variable.

  8. Effect of driving cycles on energy efficiency of electric vehicles


    Based on several typical domestic and foreign driving cycles, the energy usage efficiency of the EVs-XL 2000 type electric vehicle (EV) is analyzed. The energy usage efficiency of EVs and the evaluation index of electromotor efficiency are studied. The concepts of "interval usage percentage of energy efficiency" and "exertion degree of energy efficiency" of electromotor are presented. The effects of driving cycles on the distribution of the running status of electromotor and the efficiency are investi-gated. The efficiency of electromotor and the trend of average driving force at different driving cycles are discussed. The exertion degree of energy efficiency and the total power train efficiency of the EVs-XL 2000 type electric vehicle at typical driving cycles are analyzed and calculated. The result indicates that the driving cycle engenders a big influence on the exertion degree of electromotor energy efficiency at different driving cycles. Dissimilar driving cycles result in different efficiency distributions of electromotor, the control system as well as the average driving force and driving range are variable.

  9. At A Glance: Electric-Drive Vehicles


    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

  10. At A Glance: Electric-Drive Vehicles



    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. With the range of styles and options available, there is likely one to meet your needs. The vehicles can be divided into three categories: 1) Hybrid electric vehicles (HEVs), 2) Plug-in hybrid electric vehicles (PHEVs), and 3) All-electric vehicles (EVs).

  11. Force Measurements in Vibration and Acoustic Tests

    Scharton, T. D.


    The advent of triaxial, piezoelectric force gages and the associated signal processing is a precursor to several dynamics testing innovations. This new technology is applicable to spacecraft programs that JPL manages. An application of force measurement is force limiting (when testing spacecraft in random vibration tests). Base-drive and acoustic modal testing is a potential application.

  12. Turbulent current drive mechanisms

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua


    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  13. Polar Direct Drive

    Skupsky, S.


    Direct drive offers the potential of higher target gain on the National Ignition Facility (NIF) than x-ray drive: The initial direct-drive target design had a 1-D gain of 45 and consisted primarily of a pure cryogenic DT shell. Using the expected levels of target and laser nonuniformities for the NIF, two-dimensional (2-D) hydrodynamic simulations predicted target gains around 30.(P.W. McKenty et al.), Phys. Plasmas 8, 2315 (2001). More-recent designs have shown that higher target gains could be obtained by replacing a portion of the DT shell with ``wetted'' CH foam and by using adiabat shaping: (1) Higher-Z material (C) in the foam increases laser absorption by about 40% (from 60% absorption to 85%).(S. Skupsky et al.), in Inertial Fusion Sciences and Applications 2001, edited by K. Tanaka et al. (Elsevier, Paris, 2002), p. 240. (2) Adiabat shaping allows the main portion of the fuel to be placed on a lower adiabat without compromising target stability.(V.N. Goncharov et al.), Phys. Plasmas 10, 1906 (2003). These direct-drive concepts can be tested on the NIF, long before that facility is converted to a direct-drive (spherically symmetric) irradiation configuration. Using the NIF x-ray-drive beam configuration, some of the near-polar beams could be pointed to better illuminate the target's equator. These more-oblique, equatorial beams will have lower absorption and reduced drive efficiency than the polar beams. One strategy to compensate for the difference in polar and equatorial drive is to reduce the irradiation at the poles and employ different pulse shapes to accommodate the time-dependent variations in drive and absorption. This concept of polar direct drive (PDD) has been studied using the 2-D hydrocode DRACO to determine the requirements for achieving ignition and moderate target gain for the NIF. Experiments on the OMEGA laser will examine the effects of oblique irradiation on target drive. Results of simulations for different direct-drive target designs

  14. Analysis of Elastic Static Force of Reducer with Dual Driving Few Tooth Difference%双驱型少齿差减速器弹性静力学分析

    陈满意; 石永科


    在推导了减速器惯性力惯性力矩平衡的条件下,通过考虑内齿板变截面特性和弹性变形协调条件并建立了少齿差传动力学模型;给出并分析了内齿板偏心轴承载荷、传递的转矩随转角变化的规律以及在不同啮合角下内齿板偏心轴承的载荷变化规律.%On the base of deducing inertia force and moment of inertia balance, the force model of few teeth difference gear transmission is built by considering the characteristic of internal tooth plate variable section and the coordination condition of the elastic deformation. The load and torque transmission variation of internal tooth plate eccentric bearing under the changing rotational angle and the load variation under the different meshing angle are given out and analyzed.

  15. Novel drive mechanism for in-tube micro robots

    CHEN Yangzhi; XING Guangquan; PENG Xuefei; LIU Wenguang; YAO Huaping


    The volume of an in-tube micro robot is small and its interior space is very limited. However, conventional transmission methods are unfit to drive in-tube micro robots. A novel micro drive mechanism called the micro-elastic- meshing-wheel is presented in this paper. It can be used for transmitting power and locomotion between two shafts, which are upright and cross in a micro space. The mechanical model of the novel drive mechanism is built, and the maximal trans- mission force is deduced. Then, sufficient experiments are carried out to test maximal transmission force produced by the novel drive mechanism. The calculation and experiment results show that the novel drive mechanism can transmit sufficient power to in-tube micro robots.

  16. 忧伤与愤怒:教育社会学的情感动力--以涂尔干、麦克拉伦为例%Sadness and Anger:Emotional Driving Forces of Educational Sociology---Taking Emile Derkheim and P. Mcralen for Example



    The Emotional driving forces are subject to be ignored in the theoretical oriented reflection of educational sociology. Taking the educational sociology invented by Emile Derkheim as an example, one can see that this kind of educational sociology was shaped by the typical emotion of sadness that a classical scholar might have. In the works of Peter Mcralen ’s educational sociology, there has been a strong Marxism anger towards the capitalism and imperialism word. The emotional driving forces must also be taken into consideration when examining the development of Chinese contemporary educational sociology.%反思教育社会学时,不应仅从理论角度展开,还应关注其中的情感动力。以涂尔干的古典教育社会学为例,其中便有一种古典主义者特有的忧伤情感在起支撑作用。而在麦克拉伦的教育社会学实践中,则可以清楚看到马克思主义者对于“资本主义”及“帝国主义”体制的强烈愤怒。麦克拉伦之后的教育社会学以及当代中国教育社会学能有什么样的发展,同样也要厘清其中可能存在的情感动力。

  17. Modeling and Analysis of A Rotary Direct Drive Servovalve

    YU Jue; ZHUANG Jian; YU Dehong


    Direct drive servovalves are mostly restricted to low flow rate and low bandwidth applications due to the considerable flow forces. Current studies mainly focus on enhancing the driving force, which in turn is limited to the development of the magnetic material. Aiming at reducing the flow forces, a novel rotary direct drive servovalve(RDDV) is introduced in this paper. This RDDV servovalve is designed in a rotating structure and its axially symmetric spool rotates within a certain angle range in the valve chamber. The servovalve orifices are formed by the matching between the square wave shaped land on the spool and the rectangular ports on the sleeve. In order to study the RDDV servovalve performance, flow rate model and mechanical model are established, wherein flow rates and flow induced torques at different spool rotation angles or spool radiuses are obtained. The model analysis shows that the driving torque can be alleviated due to the proposed valve structure. Computational fluid dynamics(CFD) analysis using ANSYS/FLUENT is applied to evaluate and validate the theoretical analysis. In addition, experiments on the flow rate and the mechanical characteristic of the RDDV servovalve are carried out. Both simulation and experimental results conform to the results of the theoretical model analysis, which proves that this novel and innovative structure for direct drive servovalves can reduce the flow force on the spool and improve valve frequency response characteristics. This research proposes a novel rotary direct drive servovalve, which can reduce the flow forces effectively.

  18. Driving in a womb


    Drive thousands of kilometres on just a litre of fuel? During the annual Shell eco-marathon at the end of May, schoolchildren and students – including a team from TU Delft – demonstrated that it can indeed be done.


    陈仁朋; 胡亚元; 陈云敏


    This paper presents a method to determine driving resistance with rebound of pile-top during pile driving. The soil around the pile shaft is assumed to be rigid-plastic, while that under the pile-tip is assumed to be ideally elastoplastic. The driving force acting on the pile-top is simplified to a triangular impact force. The kinematic equation of the pile-tip is established. From the one-dimensional wave equation, the movements of the pile-tip and pile-top are determined. The rebound at the pile-top can be written in a very concise form. It is shown that the shaft resistance makes the rebound at the pile-top decrease. In particular, when the pile is very long or the soil around the pile is very stiff, the decrease is very obvious.

  20. Instant Google Drive starter

    Procopio, Mike


    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  1. Marine winch drive systems

    Clifford, M.; Smith, P.M.


    In the design of marine winch drive systems, efficiency, controllability, compactness and component layout flexibility are major considerations. This paper discusses design concepts aimed at achieving the above considerations in the design of variable speed, hydrostatic, marine winch drive systems. These concepts utilize a high pressure, load sensing pump, and a low-speed, high-torque (LSHT), radial-piston, hydraulic motor. These components are then shown applied in several open circuit hydrostatic power transmission systems.

  2. Optimized comb drive finger shape for shock-resistant actuation

    Engelen, Johan B.C.; Abelmann, Leon; Elwenspoek, Miko C.


    This work presents the analytical solution, realization and measurement of a comb drive with finger shapes optimized for shock-resistant actuation. The available force for actuating an external load determines how large shock forces can be compensated for. An analytical expression is presented for t

  3. 论阶级分析法视角下的社会历史发展动力%On the Driving Force of Social Development from the Perspective of Class Analysis



    The rationality of Marxist theory that the social basic contradiction is the basic motive force and the class struggle is the direct motive force for social development lies in that the social basic contradiction solves social basic justice,namely reasonable social wealth distribution,which is the groundwork for social development,while the class confrontation and struggle is the most direct way to realize social justice.People's essential needs and class concept are impersonal and measurable,so we can make a quantitative analysis of them from the perspective of class analysis,which is a scientific method.%马克思主义关于"社会基本矛盾是社会发展的根本动力"、"阶级斗争是社会发展的直接动力"理论的合理性在于:社会基本矛盾论要解决社会存在的基本公正问题,即社会财富分配的合理,才能为社会发展提供基础;阶级对抗和斗争是解决社会基本公正的最直接的手段和方法。有关人的基本需要及阶级概念,具有客观和可量化的特征,可纳入科学的范围进行定量分析。阶级分析法是科学的方法。

  4. Dementia and driving.

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K


    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  5. Self-driving carsickness.

    Diels, Cyriel; Bos, Jelte E


    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels.

  6. Preliminary Study of the Driving Force on the Asian Monsoon Change During the Last Millennium%近千年亚洲季风变化驱动力的初步研究

    江亭桂; 林振山; 李玉霞


    通过反演方法,利用已有的影响亚洲季风变化的相应资料,通过动力模型建立了近千年亚洲季风变化的驱动力方程,根据各指标的具体数值反演出方程中各项系数和对应的贡献率.分析方程中各气候代用指标对亚洲季风变化的影响程度,发现近千年亚洲季风并非只受到这些气候要素的线性作用,而是受到较为复杂的非线性驱动力作用,其中大气中CO2含量、印度洋海表温度、前一期季风强度、南方涛动指数、CH4气体含量、格陵兰温度、北大西洋海表温度、北半球温度等在驱动近千年亚洲季风变化中起到较为重要的作用,而在长时间尺度上对季风变化有重要影响的太阳活动,近千年中其直接影响并不十分显著,这也可能是指标精度的原因.%The Asian monsoon is an important part of the global climatic system. Previous studies have indicat-ed that the formation and change of the Asian monsoon are greatly associated with solar activity, the land-sea thermal difference, global ice volume, the uplift of Qinghai-Tibet Plateau and other climatic and geographic el-ements. The proxies of the climate records are more abundant during the last millennium than those of the oth-er history periods. The studies on the changes of the Asian monsoon during the last millennium can help us ex-plore the monsoon evolution rules and predict tendency ofthe Asian monsoon in the future. In the paper, based on the inversion method and the currently available information and data, a driving model which probably re-veals the dynamic mechanism of the Asian monsoon changes during the last millennium is established. Accord-ing to the actual quantitative values of all the proxies, we can get the coefficients and the corresponding contri-bution rates of the equation. Through the analyses of the influencing degree of each climate proxy on the Asian monsoon, the following results are obtained:1) The Asian monsoon is not only

  7. The Logic of Imagery:A Primary Driving Force of Creative Thinking--Reading Rudolf Arnheim's "Visual Thinking" Once Again%意象的逻辑:创造性思维的首要推动者




  8. Linear Motor for Drive of Belt Conveyor

    Milan Krasl


    Full Text Available This paper introduces a novel approach on the design of a linear motor for drive of belt conveyor (LMBC. The motor is a simple combination of asynchronous motor in plane. The electromagnetic forces is one of the most important parameters of electrical machines. This parameter is necessary for the checking of the design. This paper describes several variants: linear motor with slots in platens, slots in one half of platens and optimization of slots. The electromagnetic force can be found with the help of a Finite Elements Method – based program. For solution was used QuickField program.

  9. ERF Based Precision Linear Drive System

    Tönshoff, Hans Kurt; Stegmann, Axel

    The design of clutches using electrorheological fluids (ERF) or magnetorheological suspensions (MRS) offers a new approach to precision linear drive systems based on the ‘inch-worm’ principle. This principle needs two clutches or controllable clamps and one (or more) elements to vary the distance between these clamps. To perform a caterpillar-like motion the actuators are controlled in a cyclic mode. This paper presents design elements, system structure and first results of motion performance of a prototype drive system. The presented linear drive combines the high resolution of piezo actuators, the unlimited travel of the ‘inch-worm’ principle and the clutch effect of ERF without a substantial mechanical excitation. The motion of the two clamps is controlled to move a stage in point to point mode or to follow a given velocity profile. Using two piezo actuators the stage can move continuously. Pre-loaded piezo actuators control the distances between the two clamps and the central slide. Each ERF clamp is designed as a set of thin parallel steel plate electrodes which interlock with a set of ground plates. Drive force limits are given by the maximum yield force of the clamps as well as by the relation of the actuator expansion and the ERF/MRS shear stiffness in “solid” mode.

  10. Curvature Gradient Driving Droplets in Fast Motion

    Lv, Cunjing; Yin, Yajun; Tseng, Fan-gang; Zheng, Quanshui


    Earlier works found out spontaneous directional motion of liquid droplets on hydrophilic conical surfaces, however, not hydrophobic case. Here we show that droplets on any surface may take place spontaneous directional motion without considering contact angle property. The driving force is found to be proportional to the curvature gradient of the surface. Fast motion can be lead at surfaces with small curvature radii. The above discovery can help to create more effective transportation technology of droplets, and better understand some observed natural phenomena.

  11. Internet Finance as an Innovative Driving Force for Commercial Banks Transformation Strategy%互联网金融:商业银行转型战略的创新驱动力

    陆岷峰; 虞鹏飞


    trains of thought of bank development are to explore the point combining the innovative thinking of internet finance and the commercial banks transformation strategy.The introduction of internet finance is the reflection of commercial banks innovation and drive.The influence of internet finance to commercial banks is multidimensional:The payment of the third party has shaken banks ' status;internet financing has influenced the frame of bank deposit; network loan has corroded bank credit; and big data finance has inspired bank ' s innovative vigor.The internet finance thinking drives the transformation of commercial banks as follows :firstly, develop service-oriented banks with users ' thinking.Try to build up an inclusive financial thought of internet finance , develop the mass clients , and serve the vulnerable group disadvantaged group to realize the long-tail finance effect;try to set up a target system of client experience , and increase clients ' participation.Secondly, establish open banks with platform thinking.Set up outline platform on the basis of banks ' former clients with the archetype of the bank entities;set up online bank payment platform on the basis of union pay and internet; set up bank credit assurance platform by making use of clients ' credit information and internet technology; set up cloud service platform of exchange by strengthening its cooperation with materials circulation and sociality websites;and set up the unified and complete service platform of commercial banks with the general management of online and outline platforms.Thirdly, form informative banks with big data thinking.Conform the interior data of the banks thoroughly and make use of the exterior socialized data generally.Fourthly, build standard internet banks with risk thinking. Build up a globalized risk concept , take good advantage of the advanced technologies such as big data , cloud calculation and so on, and finally perfect the risk management methods.

  12. Improved linear ultrasonic motor performance with square-wave based driving-tip trajectory

    Le, Adam Y.; Mills, James K.; Benhabib, Beno


    This paper proposes the application of a non-sinusoidal periodic excitation voltage to induce a near-square-wave driving tip trajectory in linear ultrasonic motors (LUSMs). A square-wave-based trajectory can deliver superior frictional force to the moving stage in the forward stroke of the driving tip motion and reduced frictional force during the return stroke. This would reduce lost power in the periodic driving tip motion, thereby, increasing the output force and power of the LUSM. An implementation procedure is suggested to achieve the near-square-wave driving tip trajectory. The proposed approach is illustrated through realistic finite-element-based simulations using a bimodal LUSM configuration.

  13. Driving anger in Malaysia.

    Sullman, Mark J M; Stephens, Amanda N; Yong, Michelle


    The present study examined the types of situations that cause Malaysian drivers to become angry. The 33-item version of the driver anger scale (Deffenbacher et al., 1994) was used to investigate driver anger amongst a sample of 339 drivers. Confirmatory factor analysis showed that the fit of the original six-factor model (discourtesy, traffic obstructions, hostile gestures, slow driving, illegal driving and police presence), after removing one item and allowing three error pairs to covary, was satisfactory. Female drivers reported more anger, than males, caused by traffic obstruction and hostile gestures. Age was also negatively related to five (discourtesy, traffic obstructions, hostile gestures, slow driving and police presence) of the six factors and also to the total DAS score. Furthermore, although they were not directly related to crash involvement, several of the six forms of driving anger were significantly related to the crash-related conditions of: near misses, loss of concentration, having lost control of a vehicle and being ticketed. Overall the pattern of findings made in the present research were broadly similar to those from Western countries, indicating that the DAS is a valid measure of driving anger even among non-European based cultures.

  14. Study on the Evolution and Driving Forces of Carbon Emissions--In Shandong Province%碳排放演化规律与驱动因素分析--以山东省为例

    李雷鸣; 孙梁平; 刘丙泉


    Under the background of developing low-carbon economy to tackle climate change, Shandong as a major economic province and energy consumption province bears the major task of reducing emissions. However, unreasonable industrial structure and energy consumption structure, and many other factors brought a huge challenge to the successful completion of the carbon reduction tasks in Shandong Province. So, calculating the carbon emissions of Shandong, comparing with related regions, and then study the main driving factors have important practical significance for Shandong to control carbon emission. This paper uses the Kaya identity and IPCC inven-tory calculation to calculate the carbon emissions for Shandong Province and its related areas, and analyses the evolution regular of the carbon emissions in Shandong province on the basis of the vertical and horizontal comparison. Then the paper analyses the impact on carbon emissions from the view of economic development, energy intensity, carbon intensity, energy consumption structure and indus-trial structure, meanwhile proposing the carbon emission reduction countermeasures that establish recycling economy, promote industri-al structure upgrade to low-carbon, in order to provide a reference for Shandong Province to successfully achieve the emission reduction targets and improve the quality of the environment.%  在发展低碳经济应对气候变化的背景下,山东作为经济大省、能耗大省承担着重要的减排任务。然而,不合理的产业结构和能源消费结构等诸多因素,给山东省碳减排任务的顺利完成带来了巨大的挑战。因此,对山东省碳排放情况进行核算,并同相关地区开展比较研究,分析总结山东省碳排放的演化规律,进而讨论碳排放的主要驱动因素,对山东省碳排放控制具有重要的现实意义。文章应用Kaya恒等式采用IPCC的清单计算方法,对山东省及相关地区的碳排放量进行了

  15. Analysis on driving force for groundwater flow field evolution in Shijiazhuang Area in recent 50 years%近50年来石家庄地区地下水流场演变驱动力分析

    冯慧敏; 张光辉; 王电龙; 严明疆


    为了揭示石家庄地区地下水流场演变的驱动因素,基于近50年来地下水位、气候变化及开采量等相关数据,应用小波变换及模糊矩阵等研究方法,对地下水流场发生异变的主要动因及其特征进行了研究。结果表明:(1)地下水降落漏斗中心水位埋深及面积随Pe值(降水量与开采量比值)减小而增大,趋势基本符合幂函数关系,枯水年份Pe单位下降值的影响程度约是丰水年份的1.8倍和1.9倍;(2)地下水降落漏斗中心水位埋深及面积随着Re值(地下水补给量与开采量比值)增大以幂函数特征呈减小趋势;(3)上游山区水利工程的修建使下游平原区地表水体渗漏补给量减少49%,井灌回归补给量减少17%。利用该方法取得的研究成果与实际情况基本符合,可为区域地下水开发利用提供指导。%Based on data about underground water level, climatic variation and the amount of groundwater mining, and through the methods of wavelet transform (WT) and fuzzy matrix, factors inducing the abnor-mal variation of groundwater flow field in Shijiazhuang as well as the characteristics are studied, to reveal the factors driving the evolution of groundwater flow field in Shijiazhuang. The results indicate that:(1) the central level and area of groundwater depression cone decreases with the increase of Pe value (ratio of precipitation to groundwater mining),and the trend fits well to the power function,with a declining degree of Pe value in dry years 1.8 times or 1.9 times of that in wet years;(2) the central level and area of groundwater depression cone increases with Re value (ratio of replenishment to groundwater mining), which is in a trend of decrease and showed the characteristics of power function;(3) due to the construction of water conservancy projects in the upstream, the recharged quantity through infiltration of surface water de-creased 49%, and the recharged

  16. 黄土高原南部地区农业用地驱动力分析与动态模拟%Driving forces and dynamic simulation of agricultural land in the southern Loess Plateau

    李强; 任志远


    Accessing to the regional agricultural land-use change and its driving factors data from TM and ETM + image in the southern Loess Plateau and using of Binary logistic regression model,we quantitatively analyzed the dynamic evolution characteristics and spatial distribution pattern of agricultural land.And simulated the different types of agricultural land-use change using ArcGIS.The results showed that: 1)The distribution of arable land in the southern Loess Plateau is mainly affected by the distance from the town center,elevation,slope,aspect,population density,GDP unit area.The greatest effect is slope,and the second effects are elevation and population.2)The distribution of woodland is mainly affected by slope and aspect.the biggest factor is slope and the bigger factor is aspect.3)The distribution of the grass is mainly affected by slope and population density.The influencing factors for agricultural land-use are natural and human factors,including the terrain of slope and population density in the southern Loess Plateau.It shows that the most important influencing factors is human activity.Human activity is the important factor for study the agricultural land resources and the rate of change in land ecosystems.%利用黄土高原南部地区TM和ETM+遥感影像,在获取区域农业土地利用变化及其驱动因子数据的基础上,采用Binary Logistic回归模型,定量分析区域内农业用地的动态演化特征与空间分布格局,并运用ArcGIS软件进行不同类型农业用地变化模拟与输出。结果表明:1)黄土高原南部地区耕地的分布主要受距县城中心的距离、高程、坡度、坡向、人口密度、地均GDP的影响,其中受坡度影响最大,发生比expβ是0.83130204,高于其他因子;其次是高程和人口密度,发生比expβ分别为0.99932988和1.00011472。2)林地的分布主要受坡度和坡向的影响,坡度影响最大,坡向次之,发生比expβ分别为1.09136459和0.99209087。3

  17. U.S. DRIVE



    U.S. DRIVE, which stands for United States Driving Research and Innovation for Vehicle efficiency and Energy sustainability, is an expanded government-industry partnership among the U.S. Department of Energy; USCAR, representing Chrysler Group LLC, Ford Motor Company and General Motors; Tesla Motors; five energy companies – BP America, Chevron Corporation, ConocoPhillips, ExxonMobil Corporation, and Shell Oil Products US; two utilities – Southern California Edison and Michigan-based DTE Energy; and the Electric Power Research Institute (EPRI). The U.S. DRIVE mission is to accelerate the development of pre-competitive and innovative technologies to enable a full range of affordable and clean advanced light-duty vehicles, as well as related energy infrastructure.

  18. Synergetic driving concepts for bundled miniature ultrasonic linear motors.

    Mracek, Maik; Hemsel, Tobias


    Rotary ultrasonic motors have found broad industrial application in camera lens drives and other systems. Linear ultrasonic motors in contrast have only found limited applications. The main reason for the limited range of application of these very attractive devices seems to be their small force and power range. Attempts to build linear ultrasonic motors for high forces and high power applications have not been truly successful yet. To achieve larger force and higher power, multiple miniaturized motors can be combined. This approach, however, is not as simple as it appears at first glance. The electromechanical behaviour of the individual motors differs slightly due to manufacturing and assembly tolerances. The individual motor characteristics are strongly dependent on the driving parameters (frequency, voltage, temperature, pre-stress, etc.) and the driven load and the collective behaviour of the swarm of motors is not just the linear superposition of the individual drive's forces. Thus, the bundle of motors has to be synchronized and controlled appropriately in order to obtain an optimized drive that is not oversized and costly. We have investigated driving and control strategies of a set of linear ultrasonic motors. Our contribution will be divided into three main parts. In part I ultrasonic linear motors will be introduced. In part II driving strategies for a single motor as well as for a bundle of motors will be presented. These concepts will be verified by simulation results and experimental data. In part III a simplified model for the motor's electromechanical behaviour will be given.

  19. Neuromorphic meets neuromechanics, part II: the role of fusimotor drive

    Jalaleddini, Kian; Minos Niu, Chuanxin; Chakravarthi Raja, Suraj; Sohn, Won Joon; Loeb, Gerald E.; Sanger, Terence D.; Valero-Cuevas, Francisco J.


    Objective. We studied the fundamentals of muscle afferentation by building a Neuro-mechano-morphic system actuating a cadaveric finger. This system is a faithful implementation of the stretch reflex circuitry. It allowed the systematic exploration of the effects of different fusimotor drives to the muscle spindle on the closed-loop stretch reflex response. Approach. As in Part I of this work, sensory neurons conveyed proprioceptive information from muscle spindles (with static and dynamic fusimotor drive) to populations of α-motor neurons (with recruitment and rate coding properties). The motor commands were transformed into tendon forces by a Hill-type muscle model (with activation-contraction dynamics) via brushless DC motors. Two independent afferented muscles emulated the forces of flexor digitorum profundus and the extensor indicis proprius muscles, forming an antagonist pair at the metacarpophalangeal joint of a cadaveric index finger. We measured the physical response to repetitions of bi-directional ramp-and-hold rotational perturbations for 81 combinations of static and dynamic fusimotor drives, across four ramp velocities, and three levels of constant cortical drive to the α-motor neuron pool. Main results. We found that this system produced responses compatible with the physiological literature. Fusimotor and cortical drives had nonlinear effects on the reflex forces. In particular, only cortical drive affected the sensitivity of reflex forces to static fusimotor drive. In contrast, both static fusimotor and cortical drives reduced the sensitivity to dynamic fusimotor drive. Interestingly, realistic signal-dependent motor noise emerged naturally in our system without having been explicitly modeled. Significance. We demonstrate that these fundamental features of spinal afferentation sufficed to produce muscle function. As such, our Neuro-mechano-morphic system is a viable platform to study the spinal mechanisms for healthy muscle function—and its

  20. Force prediction in permanent magnet flat linear motors (abstract)

    Eastham, J. F.; Akmese, R.


    The advent of neodymium iron boron rare-earth permanent magnet material has afforded the opportunity to construct linear machines of high force to weight ratio. The paper describes the design and construction of an axial flux machine and rotating drum test rig. The machine occupies an arc of 45° on a drum 1.22 m in diameter. The excitation is provided by blocks of NdFeB material which are skewed in order to minimize the force variations due to slotting. The stator carries a three-phase short-chorded double-layer winding of four poles. The machine is supplied by a PWM inverter the fundamental component of which is phase locked to the rotor position so that a ``dc brushless'' drive system is produced. Electromagnetic forces including ripple forces are measured at supply frequencies up to 100 Hz. They are compared with finite-element analysis which calculates the force variation over the time period. The paper then considers some of the causes of ripple torque. In particular, the force production due solely to the permanent magnet excitation is considered. This has two important components each acting along the line of motion of the machine, one is due to slotting and the other is due to the finite length of the primary. In the practical machine the excitation poles are skewed to minimize the slotting force and the effectiveness of this is confirmed by both results from the experiments and the finite-element analysis. The end effect force is shown to have a space period of twice that of the excitation. The amplitude of this force and its period are again confirmed by practical results.

  1. Toyota hybrid synergy drive

    Gautschi, H.


    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  2. Toyota hybrid synergy drive

    Gautschi, H.


    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  3. Pulsation driving and convection

    Antoci, Victoria


    Convection in stellar envelopes affects not only the stellar structure, but has a strong impact on different astrophysical processes, such as dynamo-generated magnetic fields, stellar activity and transport of angular momentum. Solar and stellar observations from ground and space have shown that the turbulent convective motion can also drive global oscillations in many type of stars, allowing to study stellar interiors at different evolutionary stages. In this talk I will concentrate on the influence of convection on the driving of stochastic and coherent pulsations across the Hertzsprung-Russell diagram and give an overview of recent studies.

  4. Gears and gear drives

    Jelaska, Damir T


    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  5. Microlinear piezo drive experiments

    Azin, A. V.; Bogdanov, E. P.; Rikkonen, S. V.; Ponomarev, S. V.; Khramtsov, A. M.


    The article embraces the experimental description of the micro linear piezo drive intended for the peripheral cord tensioner in the reflecting surface shape regulator system for large-sized transformable spacecraft antenna reflectors. The research target is the experimental investigation of the micro linear piezo drive to determine the stable oscillatory system operating modes which would include improved energy conversion parameters. The following points are briefly presented: test stand construction-design of the peripheral cord tensioner; the determined frequency characteristics and the identified resonant and actual frequencies of an oscillatory system under inertia load. A series of experiments has been conducted for both different preliminary voltages and inertia mass values.

  6. Suicide mortality of young, middle-aged and elderly males and females in Japan for the years 1953-96: time series analysis for the effects of unemployment, female labour force, young and aged population, primary industry and population density.

    Yamasaki, Akiko; Araki, Shunichi; Sakai, Ryoji; Yokoyama, Kazuhito; Voorhees, A Scott


    Effects of nine social life indicators on age-adjusted and age-specific annual suicide mortality of male and female Japanese population in the years 1953-96 were investigated by multiple regression analysis on time series data. Unemployment rate was significantly related to the age-adjusted mortality in both males and females. Also, female labour force participation was positively related to the male mortality; persons and 65 and above was inversely related to the male mortality. Results on the age-specific mortality indicated that: during the 44 yr, (1) unemployment significantly related with the mortality of young, middle-aged and elderly males and young females; (2) female labour force participation significantly related with the mortality of young and elderly males and young females; aged population significantly related with the mortality of middle-aged and elderly males; (4) young population significantly related with the mortality of young and middle-aged males and females; (5) divorce significantly related with the mortality of middle-aged and elderly males and young males and females; (6) persons employed in primary industries significantly related with the mortality in middle-aged males and young males and females; and (7) population density significantly related with the mortality of middle-aged males and young females.

  7. Dangers of Texting While Driving

    ... . Print Out Texting While Driving Guide (pdf) File a Complaint with the FCC ... Office: Consumer and Governmental Affairs Tags: Consumers - Distracted Driving - Health and Safety - Texting Federal Communications Commission 445 12th Street SW, Washington, ...

  8. Research on Positive or Negative Propelling Force and Driving Force for Rural Surplus Labor Transfer-Analysis and Reflection on “Indoor Survey” Material from Kuandian Manchu Autonomous County%农村剩余劳动力转移的正反“拉力”与“推力”研究--对宽甸满族自治县“入户调查”资料的分析与思考



    通过对宽甸满族自治县的入户调查发现,农村剩余劳动力在城镇从业一定程度上提高了农村家庭的收入水平,但是当前农村剩余劳动力转移存在正反两个方向的四种动力:城市不仅存在吸引农民入城务工的“拉力”,也存在将外来务工者推回农村的“推力”;而农村不仅存在将剩余劳动力推往城市的“推力”,也存在将外出务工者拽回来的“拉力”。正是在正反“拉力”与“推力”的综合作用下,部分农民选择了“离土不离乡”或“离-返交替”的半农半工模式。因此,小城镇建设具有重要的意义:可以通过发展农村经济“拉住”劳动力,以缓解城市就业压力;同时也有利于农民选择适合自己的生产和生活方式,实现农村剩余劳动力的多元化和逐步有序转移。%“Indoor Survey” on Kuandian Manchu Autonomous County finds that the employment of rural surplus labor in the cities raises the income level of rural households to some extent, however, current rural surplus labor transfer has four kinds of driving forces in positive and negative two directions, i.e., the rural areas not only have the “propelling force” to push the rural surplus labor to the cities but also have the “driving force” to pull the migrant workers back to the rural areas, furthermore, the cities not only have the “driving force” to attract the peasants to work in the cities but also have the “propelling force” to push the migrant workers back to the rural areas. It is under the comprehensive action by “the propelling force” and “the driving force” that a part of the peasants choose half-worker-half-peasant model by“working in the cities but keeping their ID in the rural areas” or by “alternatively working in the cities or working in the rural areas”. Thus, small city construction is of important significance to “keeping” the rural labor in the rural

  9. Flooding flow variation and driving forces for Huolin catchment%霍林河流域洪水径流演变规律及驱动机制研究

    卢晓宁; 邓伟; 张树清; 熊东红


    Huolin River is one of the most important water supply sources for the Xianhai,Kerqin,and Chaganhu Wetlands in the west Songnen Plain.And its flooding plays a decisive role on the maintenance of landscape of floodplain environment system.Based on the maximum annual runoff series from the 3 representative hydrologic stations about 50 years,we analyzed the variation of flooding flow and its driving mechanisms,including natural and human disturbing aspects.These results could provide the scientific basis for the high efficiency flood hazard mitigation and floodwater utilization.The Huolin River flood was mainly caused by rainstorm,and usually occurred in July and August with plenty of rain,embodied by multimodal curves.The flood magnitude and occurrence frequencies of extreme flood of the Huolin River varied in periods and at different hydraulic stations and showed different features.With the method of Mann-Kendall,an increasing abrupt change happened in year of 1985 to 1990 overcasting the whole basin.The cut-off of flow in lower reaches since 2000 had reached at the level of abrupt change.We applied Morlet Wavelet to analyze the flooding flow,and found that the flooding flow of Huolin River varied mainly in two time scales.Interdecadal variation longer than 30 years presented extensive property,and had an tendency of increasing along the time processing.Annual variation shorter than 10 years only took on localization property,but with the stongest periodic oscillation energy.Precipitation was the most important climate factor that had profound impact on the flooding flow variation.And its effects on flooding flow changed with space-time variation.The water and earth resource development activities ultimately resulted in rising extreme hydrology event frequency,and caused the lower reaches gradually drying up in dry years and more serious flood hazard in rainy years.Future water resource development should aim at flood utility,mitigating human disturb degree

  10. Atomic force microscopic comparison of remineralization with casein-phosphopeptide amorphous calcium phosphate paste, acidulated phosphate fluoride gel and iron supplement in primary and permanent teeth: An in-vitro study

    Nikita Agrawal


    Full Text Available Context: Demineralization of tooth by erosion is caused by frequent contact between the tooth surface and acids present in soft drinks. Aim: The present study objective was to evaluate the remineralization potential of casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP paste, 1.23% acidulated phosphate fluoride (APF gel and iron supplement on dental erosion by soft drinks in human primary and permanent enamel using atomic force microscopy (AFM. Materials and Methods: Specimens were made from extracted 15 primary and 15 permanent teeth which were randomly divided into three treatment groups: CPP-ACP paste, APF gel and iron supplement. AFM was used for baseline readings followed by demineralization and remineralization cycle. Results and Statistics: Almost all group of samples showed remineralization that is a reduction in surface roughness which was higher with CPP-ACP paste. Statistical analysis was performed using by one-way ANOVA and Mann-Whitney U-test with P < 0.05. Conclusions: It can be concluded that the application of CPP-ACP paste is effective on preventing dental erosion from soft drinks.

  11. Review and prospect on driving force research of construction land expansion in the context of rapid urbanization%快速城镇化背景下建设用地扩展驱动力研究述评与展望

    张乐勤; 陈素平; 王文琴; 许信旺


    快速城镇化及经济发展背景下,我国建设用地扩展特征明显,建设用地扩展驱动力研究可为政府制定土地利用管控策略提供依据.采用文献分析法、归纳法,对已有研究成果进行了综述,综合分析表明:已有研究存在理论体系不健全;驱动因子遴选缺乏科学性;尺度界定不清晰;数据获取口径不一,遥感数据与统计数据不匹配;研究方法存在一定缺陷等不足与弊端.从人类与环境相互作用的系统观视角出发,加强学科交流,构建完整理论体系框架;注重驱动因子遴选的整体性、层次性、动态性、差异性;构建揭示空间异质差异的非线性模型,创建对模型可靠性和科学性进行检验方法;将数学模型方法、数据库技术和3S技术结合起来,创新研究方法;规范数据获取口径;加强时空尺度的敏感性研究;建设用地扩展对自然、社会经济反馈机制等方面进行了展望,以期为建设用地扩展驱动力进一步研究提供借鉴.%In the context of rapid urbanization and economic development, China's construction land expansion shows quite significant characteristics. Thus, the research on the driving force of construction land expansion can provide a basis for the government to develop land use control policies and contrive land management scheme. In this study, the literature analysis method and induction method were selected to review the existing research results. Through comprehensive analyses of the existing research results, the follwing conclusions can be drawn:the theoretical system of existing research was not perfect; the selection of driving factors was not scientific; the scale definition was not clear; the data acquisition approach was different, and the remote sensing data did not match with the those of statistics; some defects existed in the research methods as well as other deficiencies and drawbacks. For the reasons discussed above, viewed

  12. A study on the relationship between personality and driving styles.

    Poó, Fernando Martín; Ledesma, Ruben Daniel


    Research on driving behavior and personality traits is a key factor in the development of driver-oriented safety interventions. However, research is fragmented and a multidimensional perspective is lacking. The primary aim of this study is to assess the multiple relationships between driving styles and personality traits using the alternative 5-factor model. A secondary goal is to determine whether these relationships vary by gender and age. Data were collected from a sample of 908 Argentine drivers. Driving styles were assessed using the Multidimensional Driving Style Inventory. Personality was assessed with the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ-50-CC; Aluja et al. 2006) questionnaire. Different patterns of personality are associated with different driving styles. These relationships appear to be robust with respect to gender and age; however, in some cases these variables did influence the observed relationships. The results provide researchers with a more comprehensive understanding of the relationships between personality traits and driving styles. Practical prevention measures are discussed.

  13. CSI: Hard Drive

    Sturgeon, Julie


    Acting on information from students who reported seeing a classmate looking at inappropriate material on a school computer, school officials used forensics software to plunge the depths of the PC's hard drive, searching for evidence of improper activity. Images were found in a deleted Internet Explorer cache as well as deleted file space.…

  14. Chaos in drive systems

    Kratochvíl C.


    Full Text Available The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions.

  15. Fresh Drive Against Corruption


    China’s government is making efforts to prevent corruption by taking harsh measures against the illegal selection and appointment of cadres on the 10th anniversary of China’s anti-corruption drive,President Hu Jintao called fogreater efforts to carry it out.

  16. Driving with a Goat



    <正>A highway patrol officer was sitting in his car beside the road one day when he noticed a man driving with a goat in the back seat of his car.Turning on the lights,he pulled out,sped up, and pulled the man over.

  17. Drugs and driving

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.


    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for futu

  18. Drive-Through Training

    Carter, Margie


    In this article, the author discusses how the early childhood field's approach to staff training reflects the drive-through, fast-food culture. Year after year directors send their teachers to workshops to get some quick refresher techniques. The author suggests that rather than focusing professional development on topics, focus on observing…

  19. The Drive to Influence

    Rodriguez, Diego


    At the heart of the educational vocation is a drive to influence, to meaningfully affect the learning and development of others. For adult educators working in higher education, daily activities--from teaching classes to supervising student research to attending faculty meetings to sitting on advisory boards--are full of opportunities to…

  20. Driving While Intoxicated.

    Brick, John

    Alcohol intoxication increases the risk of highway accidents, the relative risk of crash probability increasing as a function of blood alcohol content (BAC). Because alcohol use is more prevalent than use of other drugs, more is known about the relationship between alcohol use and driving. Most states presume a BAC of .10% to be evidence of drunk…