WorldWideScience

Sample records for plateau honing process

  1. 3D surface topography of cylinder liner forecasting during plateau honing process

    Science.gov (United States)

    Reizer, R.; Pawlus, P.

    2011-08-01

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid SΔq as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure pv and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  2. 3D surface topography of cylinder liner forecasting during plateau honing process

    Energy Technology Data Exchange (ETDEWEB)

    Reizer, R [University of Rzeszow, Institute of Technology, Rejtana 16A, 35-959 Rzeszow (Poland); Pawlus, P, E-mail: rreizer@univ.rzeszow.pl [Rzeszow University of Technology, W. Pola 2, 35-959 Rzeszow (Poland)

    2011-08-19

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid S{Delta}q as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure p{sub v} and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  3. Multi-surface topography targeted plateau honing for the processing of cylinder liner surfaces of automotive engines

    Science.gov (United States)

    Lawrence, K. Deepak; Ramamoorthy, B.

    2016-03-01

    Cylinder bores of automotive engines are 'engineered' surfaces that are processed using multi-stage honing process to generate multiple layers of micro geometry for meeting the different functional requirements of the piston assembly system. The final processed surfaces should comply with several surface topographic specifications that are relevant for the good tribological performance of the engine. Selection of the process parameters in three stages of honing to obtain multiple surface topographic characteristics simultaneously within the specification tolerance is an important module of the process planning and is often posed as a challenging task for the process engineers. This paper presents a strategy by combining the robust process design and gray-relational analysis to evolve the operating levels of honing process parameters in rough, finish and plateau honing stages targeting to meet multiple surface topographic specifications on the final running surface of the cylinder bores. Honing experiments were conducted in three stages namely rough, finish and plateau honing on cast iron cylinder liners by varying four honing process parameters such as rotational speed, oscillatory speed, pressure and honing time. Abbott-Firestone curve based functional parameters (Rk, Rpk, Rvk, Mr1 and Mr2) coupled with mean roughness depth (Rz, DIN/ISO) and honing angle were measured and identified as the surface quality performance targets to be achieved. The experimental results have shown that the proposed approach is effective to generate cylinder liner surface that would simultaneously meet the explicit surface topographic specifications currently practiced by the industry.

  4. The Influence of Plateau Honing Process Parameters on Cylinder Bore Surface Roughness%平台珩磨加工参数对缸孔表面粗糙度的影响

    Institute of Scientific and Technical Information of China (English)

    王晓骎; 马戎; 张雪萍; 姚振强

    2015-01-01

    平台珩磨是目前被广泛应用的一种发动机缸孔精加工工艺,珩磨后缸孔的表面粗糙度直接影响缸孔的摩擦磨损性能.针对某型发动机缸孔的平台珩磨工艺,采用正交试验的方法研究平台珩磨转速、粗珩进给率、精珩时间对缸孔表面粗糙度的Abbott参数(波峰平均高度Rpk、波谷平均深度Rvk)和加工效率的影响规律.研究结果表明:珩磨转速对Rpk 、Rvk的影响最大,其次为精珩时间,粗珩进给率对其影响很小;而通过提高粗珩进给率,能够在不显著改变缸孔表面粗糙度的条件下,大幅度提升平台珩磨加工效率.%Plateau honing is a widely used method for the finishing of engine cylinder bores.Plateau honing forms the surface topography of cylinder bore which has a direct effect on the engine friction and wear performance.The influence of plateau honing process parameters (honing rotation speed,rough honing expansion speed,finish honing duration) on cylinder bore surface roughness parameters(peak roughness Rpk,valley roughness Rvk) and plateau honing efficiency is studied by means of orthogonal experiments.The result shows that honing rotation speed is the most principal influence factor on Rpk and Rvk;finish honing duration is the second most principal factor,and rough honing expansion speed does not have major influence on Rpk and Rvk.Plateau honing efficiency could be improved by increasing rough honing expansion speed without significantly changing the surface roughness of cylinder bores.

  5. Study on the relevance of some of the description methods for plateau-honed surfaces

    Science.gov (United States)

    Yousfi, M.; Mezghani, S.; Demirci, I.; El Mansori, M.

    2014-01-01

    Much work has been undertaken in recent years into the determination of a complete parametric description of plateau-honed surfaces with the intention of making a link between the process conditions, the surface topography and the required functional performances. Different advanced techniques (plateau/valleys decomposition using the normalized Abbott-Firestone curve or morphological operators, multiscale decomposition using continuous wavelets transform, etc) were proposed and applied in different studies. This paper re-examines the current state of developments and addresses a discussion on the relevance of the different proposed parameters and characterization methods for plateau-honed surfaces by considering the control loop manufacturing-characterization-function. The relevance of appropriate characterization is demonstrated through two experimental studies. They consider the effect of the most plateau honing process variables (the abrasive grit size and abrasive indentation velocity in finish-honing and the plateau-honing stage duration and pressure) on cylinder liner surface textures and hydrodynamic friction of the ring-pack system.

  6. The effect of selected parameters of the honing process on cylinder liner surface topography

    Science.gov (United States)

    Pawlus, P.; Dzierwa, A.; Michalski, J.; Reizer, R.; Wieczorowski, M.; Majchrowski, R.

    2014-04-01

    Many truck cylinder liners made from gray cast iron were machined. Ceramic and diamond honing stones were used in the last stages of operation: coarse honing and plateau honing. The effect of honing parameters on the cylinder liner surface topography was studied. Selected surface topography parameters were response variables. It was found that parameters from the Sq group were sensitive to honing parameter change. When plateau honing time varied, the Smq parameter increased, while the other parameters, Spq and Svq, were stable.

  7. 超声平台珩磨机理分析%Mechanism Study on Ultrasonic Plateau Honing

    Institute of Scientific and Technical Information of China (English)

    成全; 祝锡晶; 王建青

    2012-01-01

    Ultrasonic plateau honing device can make oil-stone have a ultrasonic vibration. It has many advantages of small grinding force, low honing temperature, long oilstone life and high processing efficiency in cylinder sleave honing. The ultrasonic pulse force and its component force is generated at the same time, with the single grit being vibrated. Component force is defined as the removing peak force, which direction is perpendicular to cross hatch. Both the pulse force and component force are analyzed, and the mechanism of size effect is explained by fracture mechanics theory. The results show that oil stone grain can cut off peak point of cross hatch, and make it into micro platform with strong pulse force and enough energy.%超声平台珩磨装置能使油石条产生超声振动,在珩磨缸套时具有磨削力小、珩磨温度低、油石不易堵塞、加工效率高等特点.对单颗磨粒在振动时产生的脉冲力,以及超声脉冲力垂直于珩磨网纹的方向分力——有效去峰力进行了分析,并用断裂力学原理来解释尺寸效应产生的机理,最后得出结论:珩磨中油石磨粒具有强大的脉冲力具有足够的能量削掉网纹峰尖成为平台,该理论对于生产实践具有重要的意义.

  8. Multi-Field Coupling Mechanism of Electrolytic In-process Dressing- Ultrasonic Honing System

    Directory of Open Access Journals (Sweden)

    Jicai Kuai

    2013-07-01

    Full Text Available This paper proposes the ELID (Electrolytic in Process Dressing ultrasonic honing system, and conducts simulation for the solution - acoustic coupling mechanism of electrolyte between the anion and cathode of ELID ultrasonic honing system. Meanwhile, a comparative experiment is carried out for the ultrasonic honing and ordinary honing. The simulation results show that there is no obvious increase of the coupling speed of the system’s electrolyte, but the rapid change of local speed, which will accelerate the electrolyte renewal around the electrode, thereby intensifying the mass transfer of reactive ion of the electrochemical double layer, increasing the updating speed of ion concentration and speeding up the electrode reaction process; the intense variations of coupling pressure further enhances the updating speed of the electrolyte; Then the electrolytic parameters, ultrasound parameters and honing parameters obtained by simulation are respectively used to conduct experiments of ELID-ultrasound honing, ultrasound honing and traditional honing for ZrO2 ceramic. The comparative experiment results show that the machining accuracy of ELID-ultrasonic honing is 10 times of the traditional honing and twice of the ultrasonic honing; the new acoustic system adopted in ELID-ultrasound honing system reduces the amplitude, so the processing efficiency increase is not significant. This ELID-ultrasonic honing system is more suitable for the ultra-precision honing of certain difficult-to-cut materials.  

  9. Manufacturing processes 2 grinding, honing, lapping

    CERN Document Server

    Klocke, Fritz

    2009-01-01

    Presents a view of the most common machining and non-machining manufacturing processes. This volume describes the characteristics of abrasive tools, their design and manufacturing, followed by the fundamentals of grinding fluids. It also discusses grinding of different materials (steel, cast iron, hard and brittle materials, nickel and titanium).

  10. 精密小孔的珩磨工艺%The honing process for precision holes

    Institute of Scientific and Technical Information of China (English)

    董鹏敏; 赵波; 王义民; 王讲生; 李永林

    2014-01-01

    为满足大批量、高效率的生产要求,采用人造铁基金刚石磨条,珩磨加工HT250铸铁零件精密小孔。介绍珩磨加工的工艺装备、工艺参数和珩磨油的配方以及加工结果。%To satisfy the mass and high efficiency production requirements , using the honing abrasive made from artificial iron fund diamond,honing the precision hole of parts made from HT 250 cast iron.Introduce the honing processing technology ,the ho-ning processing equipment ,process parameters ,honing oil formula and processing results .

  11. Global and local mapping of motor blocks liners roughness for the analysis of honing performance

    Science.gov (United States)

    Cabanettes, F.; Fahlgren, L.; Hoering, T.; Rosén, B.-G.

    2014-03-01

    The manufacturing and finishing (honing) of cylinder liners for the automotive industry is a constant challenge in order to reduce friction losses and oil consumption. A better knowledge of surfaces generated during plateau honing is then required for optimization of the process. Despite a well-known and controlled honing process, variations in surface roughness appear at both global (due to honing tool wear) and local (TDC, middle stroke, BDC) scales and need to be mapped and analysed. The following paper proposes to map the global and local variations in roughness by using a confocal 3D measuring equipment able to measure and scan any area of a cylinder liner. Six motor blocks (five liners each) are evaluated with twenty topography measurements per liner. In total, six hundred 3D measurements of size 1×1 mm are performed and roughness parameters are computed. The results show that some parameters do correlate with the honing tool wear specific to each cylinder. Experimental models could be built. Furthermore surface roughness varies significantly over the axial length of the liners due to waviness deviations combined with a lack of flexibility of the honing tool in axial direction.

  12. 油缸体盲孔的珩磨工艺优化%Dead Hole Honing Process Optimization in Cylinder Block

    Institute of Scientific and Technical Information of China (English)

    魏海生

    2012-01-01

    针对油缸体盲孔在珩磨过程中出现的加工缺陷,从人、机、料、法、环、测等几个方面进行了缺陷原因分析.在现行工艺的基础上,提出了合理的工艺优化方案,消除了加工缺陷,改善了孔的珩磨质量,并提高了油缸体盲孔珩磨加工的一次交验合格率.%By means of SMIE, reasons arc analyzed lo the defects appearing in the dead hole honing process in cylinder block. Based on (he current process, reasonable optimization proposals are put forward, which can eliminate the defects, improve hole honing quality, and increase the FTQ of dead hole honing process in cylinder body.

  13. Powerful Honing Processing of Pump Barrel for Oil Pump%抽油泵泵筒加工-强力珩磨工艺

    Institute of Scientific and Technical Information of China (English)

    吴建中

    2014-01-01

    According to the honing process characteristics of pump barrel, combined with the principle of powerful processing, this paper discussed the features and requirement of honing sand bar, and points out the notes in selection and use.%本文按照抽油泵泵筒珩磨工艺的特点,结合强力珩磨工艺的加工原理论述了珩磨砂条的特点、要求及选用和使用时需要注意的事项。

  14. Improving accuracy of holes honing

    Directory of Open Access Journals (Sweden)

    Ivan М. Buykli

    2015-03-01

    Full Text Available Currently, in precision engineering industry tolerances for linear dimensions and tolerances on shape of surfaces of processing parts are steadily tightened These requirements are especially relevant in processing of holes. Aim of the research is to improve accuracy and to enhance the technological capabilities of holes honing process and, particularly, of blind holes honing. Based on formal logic the analysis of formation of processing errors is executed on the basis of consideration of schemes of irregularity of dimensional wear and tear along the length of the cutting elements. With this, the possibilities of compensating this irregularities and, accordingly, of control of accuracy of processing applied to the honing of both throughout and blind holes are specified. At the same time, a new method of honing is developed, it is protected by the patent of Ukraine for invention. The method can be implemented both on an existing machine tools at insignificant modernization of its system of processing cycle control and on newly designed ones.

  15. Analysis of Material Removal in Alumina Ceramic Honing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The removal mechanism is of importance to the grinding of hard and brittle ceramic materials. It is more suitable to analyze the material removal during ceramics honing processes by means of indention fracture approach. There are two honing characteristics different from grinding, the honing incidental tensile stresses and the crosshatch pattern. The stresses may influence material removal of brittle ceramics with lower tensile strength. In addition, the criss-cross cutting pattern on a bore known as cros...

  16. 镀膜CBN珩轮激光钎焊基础工艺研究%Basic Process Research on Laser Brazing Film CBN on the Gear-honing-tool

    Institute of Scientific and Technical Information of China (English)

    梁国星; 吕明; 李文斌; 马麟

    2012-01-01

    完成镀膜CBN珩轮激光钎焊需要1套完整的工艺,包括珩轮基体钎焊前清洗、镀膜CBN粗化、黏结剂涂覆、钎料及磨粒固着、激光钎焊等.任意1项出现纰漏,都会对镀膜CBN钎焊连接质量造成一定的影响,降低钎焊后珩轮精度.本文在总结以往试验的基础上,对镀膜CBN珩轮激光钎焊工艺进行了基础性研究,制定出1套激光钎焊镀膜CBN珩轮制作工艺,并对激光钎焊过程中常见的镀膜CBN磨粒缺陷进行了分析,阐述了产生缺陷的原因,提出避免缺陷产生的方法,为珩轮的制备提供了新的方法,对于加快新型珩轮的开发和推动珩齿工艺的发展提供了有益的帮助.%Laser brazing on the film CBN gear-honing matrix was achieved,a perfect technology must be provided including cleaning honing matrix,CBN grit roughening treatment,coating binder on the matrix,fixing spelter and grits,laser brazing process and so on. Going awry either segment, the laser brazing connection quality among the CBN grit, gear-honing matrix and spelter would be affected to certain extent. The precision of gear-honing-tool would be decreased. Based on summarizing the experiments results,the basic technology of laser brazing the film CBN on the gear-honing matrix was studied in this paper. The defects in the process of laser brazing CBN had been analyzed,and the generated reason and solution were explained, then a new method for manufacturing gear-honing-tool is put forward. It is benefit to speeding up gear-honing-tool developing and promoting the process of honing gear.

  17. 基于正交实验的转向器阀套铰珩工艺优化的研究%Optimization of the reaming honing process of valve sleeve based on orthogonal test

    Institute of Scientific and Technical Information of China (English)

    杨筱蓉; 朱永伟; 齐翔; 徐正选

    2013-01-01

    Reaming honing process of valve sleeve are studied by orthogonal tests and theoretical analysis. Influence factors of honing quality are as follows: the roundness value are determined by spindle speed and feed speed; the surface roughness value are determined by diamond size; the honing straightness value are determined by position accuracy of machine spindle, re-positioning accuracy of bench and the positioning accuracy of clamp system. Finally, process parameters of reaming honing are optimized for the high quality machining of valve sleeve.%运用正交实验设计方法和理论分析对加工转向器阀套内孔的铰珩工艺进行了研究,确定了影响阀套内孔铰珩质量的因素.结果表明:主轴转速和进给速度是圆度的决定性因素;珩具金刚石粒度的大小决定了粗糙度大小;机床加工轴的位置精度、工作台重复定位精度和夹具系统的定位精度决定了铰珩直线度.最终优化了铰珩工艺参数,实现了阀套的高质量加工.

  18. A numerical modelling study on the processes of uplift and planation of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    董文杰; 汤懋苍

    1997-01-01

    The Tibetan Plateau has experienced a number of processes of uplift and planation alternately since about 45 Ma B. P. when it began to raise. A differential equation model for describing the Plateau altitude variation with time is formulated on the basis of previous field studies and a theoretical hypothesis: if palaeomagnetic polarity is positive, the convective activity in the earth is strong; orogenic movement is violent; and the raising velocity of the Plateau is high and vice versa . The analytical solution of the equation is obtained. The altitude variation from the beginning of the Plateau uplift to present is computed through using the geomagnetic polarity reversals timing series and interstellar atomic hydrogen concentration data. A comparison between the model results and the field studies indicates that the former is quite similar to the latter. The model results are able to basically reproduce the alternating processes of uplift and planation of the plate geological history. In the present m

  19. Effect of Ultrasonic Vibration on Cavitation Bubbles of Grinding Fluid in Honing Process%超声振动对珩磨加工过程中磨削液气泡空化作用的影响

    Institute of Scientific and Technical Information of China (English)

    祝锡晶; 郭策

    2015-01-01

    为了对超声珩磨下的磨削液空化泡进行合理预测和控制,在分析磨削液空化机理的基础上,从气泡的控制方程出发,数值对比了超声珩磨与传统珩磨对磨削液气泡运动特性的影响,并研究了声压幅值和超声频率对磨削液气泡空化的作用,最后利用声强测量仪对磨削液气泡的空化强度进行了定量测量. 结果表明:超声珩磨下气泡会发生膨胀及压缩的动力学过程,而传统珩磨下气泡会直接被压缩,且超声珩磨下气泡的溃灭速度比传统珩磨高两个数量级;当声压幅值较低时(pahoning,based on the analysis of cavitation mechanism of grinding fluid,bubble dynamics behaviors under ultrasonic honing and traditional honing were simulated numerically respectively. Effects of acoustic amplitude and ultrasonic frequency on cavitation bubble of grinding fluid were discussed. Acoustic cavitation intensity of grinding was measured employing acoustimeter quantitatively. The results show that the bubble under ultrasonic honing can present the dynamics process of expansion and compression,but the bubble under traditional honing can be compressed directly. The collapse velocity of the bubble under ultrasonic honing is higher two magnitudes than that of traditional honing. For lower acoustic amplitude (pa

  20. Large engine cylinder honing as a contribution to emissions reduction

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Josef [Nagel Maschinen- und Werkzeugfabrik GmbH, Nuertingen (Germany)

    2013-05-15

    As well as new combustion processes and aftertreatment, increasingly rigorous environmental protection regulations are also promoting advances in engine manufacturing techniques. These measures include optimised surfaces made possible using the most modern honing technologies, such as those already in widespread use in the manufacture of automotive engines. The transfer of these honing technologies to large high and medium speed engines is best achieved using new machining concepts. (orig.)

  1. An off-line simulation of land surface processes over the northern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    MinHong Song; YaoMing Ma; Yu Zhang; WeiQiang Ma; SiQiong Luo

    2014-01-01

    In order to further understand the land surface processes over the northern Tibetan Plateau, this study produced an off-line simulated examination at the Bujiao site on the northern Tibetan Plateau from June 2002 to April 2004, using the Noah Land Surface Model (Noah LSM) and observed data from the CAMP/Tibet experiment. The observed data were neces-sarily corrected and the number of soil layers in the Noah LSM was changed from 4 to 10 to enable this off-line simulation and analysis. The main conclusions are as follows:the Noah LSM performed well on the northern Tibetan Plateau. The simulated net radiation, upward longwave radiation, and upward shortwave radiation demonstrated the same remarkable annual and seasonal variation as the observed data, especially the upward longwave radiation. The simulated soil tem-peratures were acceptably close to the observed temperatures, especially in the shallow soil layers. The simulated freezing and melting processes were shown to start from the surface soil layer and spread down to the deep soil layers, but they took longer than the observed processes. However, Noah LSM did not adequately simulate the soil moisture. Therefore, addi-tional high-quality, long-term observations of land surface-atmosphere processes over the Tibetan Plateau will be a key factor in proper adjustments of the model parameters in the future.

  2. Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3H)-ones via [Cu]-Catalysis Using Water as the Green Solvent.

    Science.gov (United States)

    Mahendar, Lodi; Satyanarayana, Gedu

    2015-07-17

    An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular "cyanation" of o-bromobenzyl alcohols → in situ intramolecular "nucleophilic attack" → "hydrolysis" is presented, for the synthesis of isobenzofuran-1(3H)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent.

  3. Effects of the soil freeze-thaw process on the regional climate of the Tibet Plateau

    Science.gov (United States)

    Luo, S., Sr.; Chen, B.; Lu, S.; Zhang, Y.; Ma, D.

    2015-12-01

    Single-point and regional simulation experiments on the Tibet Plateau, both with and without consideration of the soil freeze-thaw process, were set up with CLM3.5 and RegCM4 models. Comparison of the simulated soil temperature and moisture, surface energy flux, and upper-lower atmospheric circulation showed that the regional climate can be influenced by the freeze-thaw process of soil. The results indicate that the freeze-thaw process is a buffer to the seasonal changes in soil and near-surface temperatures and strengthens the energy exchange between the soil and the atmosphere. During the freeze (thaw) process, releasing (absorbing) of phase change energy retards the cooling (heating) effect of air temperature on soil. The soil freeze-thaw process increases (decreases) the surface heat source of the plateau in winter (summer), which increases (decreases) the near-surface temperature in winter (summer). Promoted by atmospheric circulation, the soil freeze-thaw process influences climate at the high and low altitudes of the plateau; this may also contribute to the maintenance of the South Asia High. In the early stages of permafrost degradation, the regional climate effects of freezing and thawing may accelerate the degradation of permafrost.

  4. Optimization of Honing Wheel Structure Parameters in Ultra-precision Plane Honing

    Institute of Scientific and Technical Information of China (English)

    SYOJI; Katsuo

    2002-01-01

    Free abrasive particle machining in simple machine such as: honing, polishing can get higher surface finish mirror, but surface error, and working procedure is hard to control. Therefore, the vertical disposed ultra-precision plane honing method by ultra-particle diamond honing wheel is put forward to. The results of experiments indicate: plane-honing wheel has higher machining accuracy and machining efficiency. But at the same time the structure parameters of honing wheel effects on machining accuracy. B...

  5. Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

    Directory of Open Access Journals (Sweden)

    Kamil Erkan

    2011-01-01

    Full Text Available The Qinghai-Tibetan Plateau is the largest and the highest area in the world with distinct and competing surface and subsurface processes. The entire Plateau has been undergoing crustal deformation and accompanying isostatic uplift as a result of the Cenozoic collision of the Indian and Eurasian continents. Regional secular surface mass changes include the melting of mountain glaciers and ice caps, and permafrost layer degradation due to global warming. There is also a plausible effect of glacial isostatic adjustment due to the removal of a possible Pleistocene ice-sheet. In this article, we present an assessment of the sizes and extents of these competing interior and exterior dynamical processes, and their possible detections using contemporary space geodetic techniques. These techniques include, in addition to GPS, satellite radar altimetry over land, and temporal gravity field measurements from the Gravity Recovery and Climate Experiment (GRACE satellite mission. These techniques are complementary: land satellite altimetry, similar to GPS, is sensitive only to surface uplift, whereas GRACE is sensitive to both surface uplift and mass changes inside the Earth. Each process may dominate the others in a particular region. Our analysis shows that GRACE data are more sensitive (than GPS or land altimetry to hydrologic and meteorology signals, some of which are larger than the combined effect of geodynamic processes and permafrost degradation.

  6. Thawing and freezing processes of active layer in Wudaoliang region of Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interaction between permafrost and atmosphere is accomplished through transfer of heat and moisture in the overlay active layer. Thus, the research on the thermal and hydro- dynamics of active layer during the thawing and freezing processes was considered a key to revealing the heat and moisture exchanges between permafrost and atmosphere. The monitoring and research on active layer were conducted because permafrost occupies about two thirds of the total area of the Tibetan Plateau. Based on the analysis of the ground temperature data and soil moisture data of monitoring near the Wudaoliang region of the Tibetan Plateau, the thawing and freezing processes of active layer were divided into four stages, i.e. summer thawing stage (ST), autumn freezing stage (AF), winter cooling stage (WC) and spring warming stage (SW). Coupled heat and water flow is much more complicated in ST and AF, and more amount of water is migrating in these two stages. Heat is transferred mainly via conductive heat flow in the other two stages, and less water migrated. Four water migration and coupled heat flow processes were addressed for the thawing and freezing stages, which are water infiltration driven by gravity, moisture advection and distillation driven by temperature and osmotic gradients, water migration driven by capillarity and unfrozen water migration driven by temperature gradient. The water content near the permafrost table tends to increase after one thawing and freezing cycle, which is the main reason for the development of thick ground ice layer near permafrost table.

  7. Honing Language Skills Using Blogs

    Science.gov (United States)

    Bhavana, A. R.

    2009-01-01

    Proficiency in English is a prerequisite for students to bag a place in the on/off campus interviews. Irrespective of the profession, vocation and background the students have to hone their LSRW skills in English. Selection procedures like group discussion and video conferencing are hurdles to students who lack language proficiency in English. All…

  8. Study on characteristics of single cavitation bubble considering condensation and evaporation of kerosene steam under ultrasonic vibration honing.

    Science.gov (United States)

    Ye, Linzheng; Zhu, Xijing; Wang, Lujie; Guo, Ce

    2018-01-01

    Ultrasonic vibration honing technology is an effective means for materials difficult to machine, where cavitation occurs in grinding fluid under the action of ultrasound. To investigate the changes of single cavitation bubble characteristics in the grinding area and how honing parameters influence bubble characteristics, a dynamic model of single cavitation bubble in the ultrasonic vibration honing grinding area was established. The model was based on the bubble dynamics and considered the condensation and evaporation of kerosene steam and honing processing environment. The change rules of bubble radius, temperature, pressure and number of kerosene steam molecules inside the bubble were numerically simulated in the process of bubble moving. The results show that the condensation and evaporation of kerosene steam can help to explain the changes of temperature and pressure inside the bubble. Compared with ultrasonic vibration, the amplitude of bubble radius is greatly suppressed in the ultrasonic honing environment. However, the rate of movement of the bubble is faster. Meanwhile, the minimum values of pressure and temperature are larger, and the number of kerosene steam molecules is less. By studying the effect of honing factors on the movement of the cavitation bubble, it is found that honing pressure has a greater influence on bubble evolution characteristics, while rotation speed of honing head has a minor effect and the reciprocating speed of honing head has little impacts. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Rising process of the Qinghai-Xizang (Tibet) Plateau and its mechanism

    Institute of Scientific and Technical Information of China (English)

    钟大赉; 丁林

    1996-01-01

    The rising of the Qinghai-Xizang Plateau has character of multistage (45-38 Ma, 25-17 Ma, 13-8 Ma, 3 Ma-present), inhomogeneity and hetero-speed. The whole uprising of the plateau and local rapid rising in its periphery since Late Pliocene is a synthetical result of at least two or more mechanisms.

  10. Satellite Remote Sensing Analysis to Monitor Desertification Processes in Central Plateau of Mexico

    Science.gov (United States)

    Becerril, R.; González Sosa, E.; Diaz-Delgado, C.; Mastachi-Loza, C. A.; Hernández-Tellez, M.

    2013-05-01

    Desertification is defined as land degradation in arid, semi-arid and sub-humid areas due to climatic variations and human activities. Therefore there is a need to monitor the desertification process in the spatiotemporal scale in order to develop strategies to fight against desertification (Wu and Ci, 2002). In this sense, data provided by remote sensing is an important source for spatial and temporal information, which allows monitoring changes in the environment at low cost and high effectiveness. In Mexico, drylands hold 65% of the area, with about 1,280,494 km2 (UNESCO, 2010), where is located 46% of the national population (SEMARNAT, 2008). Given these facts, there is interest in monitoring the degradation of these lands, especially in Mexico because no specific studies have identified trends and progress of desertification in the country so far. However, it has been considered land degradation as an indicator of desertification process. Thus, it has been determined that 42% of soils in Mexico present some degradation degree. The aim of this study was to evaluate the spatial and temporal dynamics of desertification for 1993, 2000 and 2011 in the semiarid central plateau in Mexico based on demographic, climatic and satellite data. It took into consideration: 1) the Anthropogenic Impact Index (HII), based on the spatial population distribution and its influence on the use of resources and 2) the Aridity Index (AI), calculated with meteorological station records for annual rainfall and potential evapotranspiration. Mosaics were made with Landsat TM scenes; considering they are a data source that allows evaluate surface processes regionally and with high spectral resolution. With satellite information five indices were estimated to assess the vegetation and soil conditions: Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), Weighted Difference Vegetation Index (WDVI), Grain Size Index (GSI) and Bare Soil Index (BSI). The rates

  11. Microbial processes and factors controlling their activities in alkaline lakes of the Mongolian plateau

    Science.gov (United States)

    Namsaraev, Zorigto B.; Zaitseva, Svetlana V.; Gorlenko, Vladimir M.; Kozyreva, Ludmila P.; Namsaraev, Bair B.

    2015-11-01

    A striking feature of the Mongolian plateau is the wide range of air temperatures during a year, -30 to 30°C. High summer temperatures, atmospheric weathering and the arid climate lead to formation of numerous alkaline soda lakes that are covered by ice during 6-7 months per year. During the study period, the lakes had pH values between 8.1 to 10.4 and salinity between 1.8 and 360 g/L. According to chemical composition, the lakes belong to sodium carbonate, sodium chloride-carbonate and sodium sulfate-carbonate types. This paper presents the data on the water chemical composition, results of the determination of the rates of microbial processes in microbial mats and sediments in the lakes studied, and the results of a Principal Component Analysis of environmental variables and microbial activity data. Temperature was the most important factor that influenced both chemical composition and microbial activity. pH and salinity are also important factors for the microbial processes. Dark CO2 fixation is impacted mostly by salinity and the chemical composition of the lake water. Total photosynthesis and sulfate-reduction are impacted mostly by pH. Photosynthesis is the dominant process of primary production, but the highest rate (386 mg C/(L•d)) determined in the lakes studied were 2-3 times lower than in microbial mats of lakes located in tropical zones. This can be explained by the relatively short warm period that lasts only 3-4 months per year. The highest measured rate of dark CO2 assimilation (59.8 mg C/(L•d)) was much lower than photosynthesis. The highest rate of sulfate reduction was 60 mg S/(L•d), while that of methanogenesis was 75.6 μL CN4/(L•d) in the alkaline lakes of Mongolian plateau. The rate of organic matter consumption during sulfate reduction was 3-4 orders of magnitude higher than that associated with methanogenesis.

  12. [Degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau, Southwest China].

    Science.gov (United States)

    Shang, Wen; Yang, Yong-Xing

    2012-12-01

    Two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA) were employed to analyze the degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau. The plant communities in the lakeside wetland could be classified into four associations, according to the TWINSPAN results. The succession patterns of the plant community were represented by aquatic plant community --> swamp plant community --> swamp meadow plant community --> meadow plant community. During the processes of succession, the plant community coverage, density, Shannon diversity index, species richness, and plant aboveground biomass increased, whereas the community height decreased. The succession of the plant hydro-ecotypes followed the sequence of aquatic --> helophyte --> hygrophyte --> mesophyte. With the succession of the plant community, the wetland water quality indices salinity, alkalinity, and hardness decreased but ammonium nitrogen and total phosphorus concentrations increased, while total nitrogen and nitrate nitrogen concentrations showed no significant changes. Meanwhile, the soil pH and soil organic matter and total nitrogen contents decreased gradually, soil total phosphorous and potassium contents were increasing, whereas soil available phosphorous and potassium contents decreased after an initial increase. The CCA showed that the community species composition and structure were mainly affected by the wetland water gradient. The soil pH and total phosphorus content and the water total nitrogen and ammonium nitrogen concentrations had significant effects on the wetland plant species distribution and plant community succession.

  13. Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Climate warming must lead the mainly air temperature controlled permafrost to degrade.Based on the numerical simulation,the process of permafrost degradation can be divided into five stages,i.e.,starting stage,temperature rising stage,zero geothermal gradient stage,talic layers stage,and disappearing stage,according to the shape of ground temperature profile.Permafrost on the Qinghai-Tibet Plateau (QTP) is generally considered a relic from late Pleistocene,and has been degenerating as a whole during Holocene.According to spatial-temporal compensation,the present thermal state discrepancy of permafrost in different areas on the QTP may correspond with their degradation stages.On the QTP,permafrost in the high and middle mountains belongs to temperature rising stage,the permafrost thermal state is transiting from late rising temperature stage to zero geothermal gradient stage that is distributed in the middle-low-mountains.Permafrost that is in a zero gradient stage mainly appears in the high plateau and valley,whereas the transition from zero gradient stage to talic layers stage of permafrost is located in the vicinity of the lower limit of permafrost,and permafrost is disappearing from margin of perennially frozen ground.There are two modes of perennially frozen ground thawing,thawing from top to bottom and thawing from bottom to top respectively.During the temperature rising stage,when the heat flux in the perennially frozen soil layer is less than that in the unfrozen soil underlying frozen soil layer,the geothermal flux is partly used to thaw the base of permafrost,and permafrost thaws from bottom to top.With the decrease of thermal gradient in the perennially frozen ground,the heat that is used to thaw permafrost base increases,and geothermal heat will be entirely consumed to thaw the base of permafrost until the temperature gradient reaches zero thermal gradient state.On the other hand,the disappearance of permafrost may be delayed by "thermal offset" and

  14. Honing Theory: A Complex Systems Framework for Creativity

    CERN Document Server

    Gabora, Liane

    2016-01-01

    This paper proposes a theory of creativity, referred to as honing theory, which posits that creativity fuels the process by which culture evolves through communal exchange amongst minds that are self-organizing, self-maintaining, and self-reproducing. According to honing theory, minds, like other selforganizing systems, modify their contents and adapt to their environments to minimize entropy. Creativity begins with detection of high psychological entropy material, which provokes uncertainty and is arousalinducing. The creative process involves recursively considering this material from new contexts until it is sufficiently restructured that arousal dissipates. Restructuring involves neural synchrony and dynamic binding, and may be facilitated by temporarily shifting to a more associative mode of thought. A creative work may similarly induce restructuring in others, and thereby contribute to the cultural evolution of more nuanced worldviews. Since lines of cultural descent connecting creative outputs may exhi...

  15. An Experimental Simulation Method of Erosion Process on Gully Erosion in Loess Plateau in China

    Science.gov (United States)

    Gao, Jianen; Zhang, Yuanxing

    2017-04-01

    In view of simulation difficultment of the field gully erosion process because of complex of rainfall runoff erosion mechanism and gully geometry a design means and experimentation technology and its verification test were given based on similarity theory and hydrodynamic principles. The basic ideas was that the erosion process of the field erosion gully was forecast by constructing similar model. The model and antetype should be in obedience to the same physical equations of rainfall, runoff, erosion, sediment transport, bed deformation and Soil water transport. The geometric, kinematical and dynamic similarity must be obeyed for these models. The primary similarity scale relation expressions were the ones of the geometric, rainfall, flow, erosion sediment transport and soil water movement similarity etc. The similarity of the hydraulic boundary was the necessary and sufficient condition between the model and the prototype. The gully prototype is one of Majiagou of Ansai county of Yanan City of Shaanxi Province in China. Its location is 36°53'55.75"N and 109°13'39.08"E. The model experiment wan carried out in State Key Laboratory of Soil Erosion and Dry land Farming On the Loess Plateau in Institute of Soil and Water Conservation of Northwest A&F University. First soil was selected by starting velocity similar. Second, the normal and scale 10 experiment model was built under complying with the similarities of geometric, rainfall, flow, erosion production sediment transport and bed deformation etc. The model hydraulic boundary from the prototype was the factor of the test process of rainfall. The experiment results indicated that the extreme rainstorm gully erosion process of the prototype could be reappeared. The equivalent rainfall process of gully prototype were that the rainfall intensity was 1.25 mm/min and the lasting time was 508 min and precipitation was 636mmn. Both the erosion amount and the erosion gully topography of the scale model were successfully

  16. Electrochromic Type E-Paper Using Poly(1H-Thieno[3,4-d]Imidazol-2(3H)-One) Derivatives by a Novel Printing Fabrication Process

    Science.gov (United States)

    Kondo, Yoshiro; Tanabe, Hirofumi; Kudo, Hidetoshi; Nakano, Kirihiro; Otake, Tomiaki

    2011-01-01

    In this study, we report poly(1H-thieno[3,4-d]imidazol-2(3H)-one) (pTIO) derivatives for an electrochromic (EC) type e-paper and its novel printing fabrication process. pTIO is a kind of conductive polymer (CP) s which are known as one of the EC materials. The electrochromism of pTIO is unique, because its color in doped state is almost transparent (pale gray). A transparent state is required to show a white color in a see-through view of an EC type e-paper. An electrochromism of CP has a good memory effect which is applicable for e-paper. The corresponding monomers of CP are able to be polymerized with an electrochemical method, which be made good use of for the fabrication process of e-paper. pTIO derivatives are copolymerized with other pi-conjugated X unit, which adjusts the color of electrochromism. Finally, we fabricated a segment matrix EC display using pTIO derivatives by ink-jet printing. PMID:28824131

  17. Electrochromic Type E-Paper Using Poly(1H-Thieno[3,4-d]Imidazol-2(3H-One Derivatives by a Novel Printing Fabrication Process

    Directory of Open Access Journals (Sweden)

    Kirihiro Nakano

    2011-12-01

    Full Text Available In this study, we report poly(1H-thieno[3,4-d]imidazol-2(3H-one (pTIO derivatives for an electrochromic (EC type e-paper and its novel printing fabrication process. pTIO is a kind of conductive polymer (CP s which are known as one of the EC materials. The electrochromism of pTIO is unique, because its color in doped state is almost transparent (pale gray. A transparent state is required to show a white color in a see-through view of an EC type e-paper. An electrochromism of CP has a good memory effect which is applicable for e-paper. The corresponding monomers of CP are able to be polymerized with an electrochemical method, which be made good use of for the fabrication process of e-paper. pTIO derivatives are copolymerized with other pi-conjugated X unit, which adjusts the color of electrochromism. Finally, we fabricated a segment matrix EC display using pTIO derivatives by ink-jet printing.

  18. Edward Wheeler Hones Jr. (1922-2012)

    Science.gov (United States)

    Baker, Daniel N.; McPherron, Robert L.; Birn, Joachim

    2013-02-01

    Space physicist Edward Wheeler Hones Jr. died on 17 September 2012 at his home in Los Alamos, N. M. He was 90 years old. The cause of death was a heart attack that came following a brief hospitalization.

  19. ECO-ENVIRONMENT CHANGE AND SOIL EROSION PROCESS IN THE RECLAIMED FORESTLAND OF THE LOESS PLATEAU

    Institute of Scientific and Technical Information of China (English)

    ZHA Xiao-chun; TANG Ke-li

    2003-01-01

    Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year da-ta observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm water-stable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength de-creased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable ag-gregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change ofeco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.

  20. Cyanobacteria in lakes on Yungui Plateau, China are assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use

    Science.gov (United States)

    Liao, Jingqiu; Zhao, Lei; Cao, Xiaofeng; Sun, Jinhua; Gao, Zhe; Wang, Jie; Jiang, Dalin; Fan, Hao; Huang, Yi

    2016-11-01

    Plateau lakes are important ecosystems with diverse ecological functions. Cyanobacteria play a key role in plateau lakes as primary producers. However, they are threatening when dense blooms occur. Identifying cyanobacteiral biogeography and the mechanism of assembly processes shaping the distribution of cyanobacteria in plateau lakes is critical for understanding cyanobacterial ecology and applying it to lake management. In the present study, the biogeographic pattern and importance of neutral and niche processes in assembly of cyanobacteria in 21 lakes on Yungui Plateau, China were examined. Results showed that cyanobacteria exhibit unique biogeographic pattern, and most of them have a narrow habitat preference in plateau lakes. They were assembled via niche processes driven by water physicochemical property, lake morphology and watershed land-use, which explained 62.4% of the biological variation. Neutral processes were not at play. Water physicochemical property (key variables - dissolved oxygen, salinity, trophic status and pH) was the most dominant driver shaping its unique biogeographic pattern. Watershed land-use especially urban land, water body and agricultural land also exhibited a strong impact on cyanobacterial distribution, followed by lake morphology. As most of the cyanobacteiral genus detected in these plateau lakes were potential toxin-producers, this study indicated that in order to protect waters from toxic-bloom in the future, reducing nutrient loading and land-use practices are two practical approaches in plateau lake management.

  1. Consequences of hyperconcentrated flow for process-based soil erosion modelling on the Chinese Loess Plateau

    NARCIS (Netherlands)

    Hessel, R.

    2006-01-01

    High sediment concentrations in runoff are a characteristic feature of the Chinese Loess Plateau, and are probably caused by factors such as the occurrence of erodible materials on steep slopes, the characteristics of the loess and the harsh climate that results in low plant cover. When sediment con

  2. Examination and Research of the Surface Topography of Ultrasonic Vibration Honing Nd-Fe-B

    Institute of Scientific and Technical Information of China (English)

    Xi-jing ZHU; Zhi-meng LU; Jian-qing WANG; Quan CHENG

    2010-01-01

    The mechanism of ultrasonic vibration honing Nd-Fe-B has been briefly elaborated after the introduction of the strategic significanoe of processing Nd-Fe-B.Based on the formation principle of Scanning Electrvnic NTicroscope (SFM),and at the exarrnination with the aid of SEM to the ultrasonic vibration honing Nd-Fe-B materials superficial microscopic topography,the paper discusses the new processing mechanism according to the SFM examination picture.The research indicates that as a result of supersonic high frequency vibration,the path of the abrasion extends at the same time,and the supersonic cavitation effect fonts the intense shock-wave,impacting Nd-Fe-B material's internal surface,providing the supersonic energy for the superficial abrasive dust's elimination,which directly explain tat the honing processing efficiency is entranced,and the processing surface rwghness is high.

  3. Processing, validating, and comparing DEMs for geomorphic application on the Puna de Atacama Plateau, northwest Argentina

    Science.gov (United States)

    Purinton, Benjamin; Bookhagen, Bodo

    2016-04-01

    This study analyzes multiple topographic datasets derived from various remote-sensing methods from the Pocitos Basin of the central Puna Plateau in northwest Argentina at the border to Chile. Here, the arid climate and clear atmospheric conditions and lack of vegetation provide ideal conditions for remote sensing and Digital Elevation Model (DEM) comparison. We compare the following freely available DEMs: SRTM-X (spatial resolution of ~30 m), SRTM-C v4.1 (90 m), and ASTER GDEM2 (30 m). Additional DEMs for comparison are generated from optical and radar datasets acquired freely (ASTER Level 1B stereo pairs and Sentinal-1A radar), through research agreements (RapidEye Level 1B scenes, ALOS radar, and ENVISAT radar), and through commercial sources (TerraSAR-X / TanDEM-X radar). DEMs from ASTER (spatial resolution of 15 m) and RapidEye (~5-10 m) optical datasets are produced by standard photogrammetric techniques and have been post-processed for validation and alignment purposes. Because RapidEye scenes are captured at a low incidence angle (validated against over 400,000 differential GPS (dGPS) measurements gathered during four field campaigns in 2012 and 2014 to 2016. Of these points, more than 250,000 lie within the Pocitos Basin with average vertical and horizontal accuracies of 0.95 m and 0.69 m, respectively. Dataset accuracy is judged by the lowest standard deviations of elevation compared with the dGPS data and with the SRTM-X control DEM. Of particular interest in the field of quantitative geomorphology are topometrics (e.g., relief, channel steepness, and hillslope concavity) derived from the DEMs. The accuracy of these metrics is partly dependent on the overall DEM accuracy, but also on the accuracy of the depiction of the river network (a small areal fraction of the DEM). In addition, several topometrics depend on the first and second derivative of elevation (slope and curvature), which are affected by DEM accuracy and noise. In light of these issues

  4. The Influence Study of Ultrasonic honing parameters to workpiece surface temperature

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoqiang

    2016-01-01

    Full Text Available Ultrasonic vibration honing(UVH, a machine technology, has a lot of advantages. Lower grinding temperature is a significant character and is beneficial for both processing and workpiece surface. But the high temperature caused by big honing pressure becomes the main factor to produce workpiece heat damage in grinding zone. In various honing parameter combinations, the showing effect is different. Based on the thermodynamics classical theory, established the heat transfer equation for grinding zone, simplified the model and obtained the two-dimenssion temperature field expression for workpiece, then simulated the temperature changing trend in a variety of conditions. It is shown that themain temp is in a range of 700K to 1200K. In addition, the variation is huge for every parameter. The study provides a theoretical basis for deeply seeking reasonable machining parameter and obtaining better workpiece quality.

  5. Extrude Hone deburring with X-base media

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1973-09-01

    Small precision mechanisms must have burr-free, sharp-edged parts to operate well. Controlling the size of burrs can lower burr removal costs and improve edge repeatability. Study results indicated that with conventional tooling approaches, Extrude Hone deburring with x-base media removes more material from the hole than desired and is less repeatable than required on precision miniature parts. With this media, the process is most applicable to precision miniature parts with burrs less than 25.4 ..mu..m thick, allowable hole size changes equal to burr thickness, and allowable hole size repeatability of +-0.2 times the actual average hole size change.

  6. Carbonatite metasomatized peridotite xenoliths from southern Patagonia: implications for lithospheric processes and Neogene plateau magmatism

    Science.gov (United States)

    Gorring, Matthew L.; Kay, Suzanne M.

    The mineral chemistry, major and trace element, and Sr-Nd isotopic composition of Cr-diopside, spinel peridotite xenoliths from the Estancia Lote 17 locality in southern Patagonia document a strong carbonatitic metasomatism of the backarc continental lithosphere. The Lote 17 peridotite xenolith suite consists of hydrous spinel lherzolite, wehrlite, and olivine websterite, and anhydrous harzburgite and lherzolite. Two-pyroxene thermometry indicates equilibration temperatures ranging from 870 to 1015°C and the lack of plagioclase or garnet suggests the xenoliths originated from between 40 and 60km depth. All of the xenoliths are LILE- and LREE-enriched, but have relatively low 87Sr/86Sr (0.70294 to 0.70342) and high ɛNd (+3.0 to +6.6), indicating recent trace element enrichment ( 25Ma, based on the low 87Sr/86Sr and high Rb concentrations of phlogopite separates) in the long-term, melt-depleted Patagonian lithosphere. Lote 17 peridotite xenoliths are divided into two basic groups. Group 1 xenoliths consist of fertile peridotites that contain hydrous phases (amphibole+/-phlogopite+/-apatite). Group 1 xenoliths are further subdivided into three groups (a, b, and c) based on distinctive textures and whole-rock chemistry. Group 1 xenolith mineralogy and chemistry are consistent with a complex metasomatic history involving variable extents of recent carbonatite metasomatism (high Ca/Al, Nb/La, Zr/Hf, low Ti/Eu) that has overprinted earlier metasomatic events. Group 2 xenoliths consist of infertile, anhydrous harzburgites and record cryptic metasomatism that is attributed to CO2-rich fluids liberated from Group 1 carbonatite metasomatic reactions. Extremely variable incompatible trace element ratios and depleted Sr-Nd isotopic compositions of Lote 17 peridotite xenoliths indicate that the continental lithosphere was neither the primary source nor an enriched lithospheric contaminant for Neogene Patagonian plateau lavas. Neogene plateau magmatism associated with formation

  7. CO2 processes in an alpine grassland ecosystem on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    PEIZhiyong; OUYANGHua; ZHOUCaiping; XUXingliang

    2003-01-01

    In this paper, the CO2 concentrations profile from 1.5 m depth in soil to 32 m height in atmosphere were measured from July 2000 to July 2001 in an alpine grassland ecosystem located in the permafrost area on the Tibetan Plateau, which revealed that CO2 concentrations varied greatly during this study period. Mean concentrations during the whole experiment in the atmosphere were absolutely lower than the CO2 concentrations in soil, which resulted in CO2 emissions from the alpine steppe soil to the atmosphere. The highest CO2 concentration was found at a depth of 1.5 m in soil while the lowest CO2 concentration occurred in the atmosphere. Mean CO2 concentrations in soil generally increased with depth. This was the compositive influence of the increasing soil moistures and decreasing soil pH, which induced the increasing biological activities with depth. Temporally, the CO2 concentrations at different layers in air remained a more steady state because of the atmospheric turbulent milking. During the seasonal variations, CO2 concentrations at surface soil interface showed symmetrical patterns, with the lowest accumulation of CO2 occurring in the late winter and the highest CO2 concentration in the growine seasons.

  8. Land use and land cover change processes in China's eastern Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    JinChang Li; HaiXia Liu; Yong Liu; ZhiZhu Su; ZiQiang Du

    2015-01-01

    Using Landsat remote sensing images, we analyzed changes in each land use type and transitions among different land use types during land use and land cover change (LUCC) in Ningwu County, located in the eastern Loess Plateau of China, from 1990 to 2010. We found that grassland, woodland, and farmland were the main land use types in the study area, and the area of each type changed slightly from 1990 to 2010, whereas the area of water, construction land, and unused land increased greatly. For the whole area, the net change and total change were insignificant due to weak human activity intensity in most of the study area, and the LUCC was dominated by quasi-balanced two-way transitions from 1990 to 2010. The insignificant overall amount of LUCC appears to have resulted from offsetting of rapid increases in population, economic growth, and the im-plementation of a program to return farmland to woodland and grassland in 2000. This program converted more farmland into woodland and grassland from 2000 to 2010 than from 1990 to 2000, but reclamation of woodland and grassland for use as farmland continued from 2000 to 2010, and is a cause for concern to the local government.

  9. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States); Vala, David [Murray High School, Murray, UT 84107 (United States); Reese, Barbara K. [Butler Middle School, Cottonwood Heights, UT 84121 (United States); Freedman, Dina R. [Hillside Middle School, Salt Lake City, UT 84108 (United States); Stenten, Christina J. [Draper Park Middle School, Draper, UT 84020 (United States); Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States)

    2015-11-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  10. Effects of Permafrost Degradation on Soil Hydrological Processes in Alpine Steppe on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    Yin Zhifang; Ouyang Hua; Yang Zhaoping

    2012-01-01

    Permafrost degradation is prevalent on the Qinghai-Ti-bet Plateau. This may lead to changes in water and heat transition in soils and thus affect the structure and function of ecosystems. In this paper, using the measured data of alpine steppe in Wud- aoliang assessed the model performance in simulating soil freezing and thawing processes. Comparison of the simulated results by simultaneous heat and water (SHAW) model to the measured data showed that SHAW model performed satisfactorily. Based on analyzing the simulated and predicted results, two points were obtained: (1) freezing and thawing of the active layer proceeded both from the soil surface downward. Compared with the freezing process, the thawing process was slower. The freezing period persisted in the surface layer (4 cm depth) for about 5 months; (2) in the next 50 years, frozen period would be shorten about 20 days in the top 100 cm depth while the thawing would start earlier 40 days than present. Soil water storage in the 0-60 cm would de- crease by 22% averagely, especially from June to August when the vegetation is at the dominating water consumed stage. Therefore, this kind of permafrost degradation as active layer freezing and thawing processes changes will reduce soil water content and thus influence those ecosystems above it.

  11. CENTRAL PLATEAU REMEDIATION

    Energy Technology Data Exchange (ETDEWEB)

    ROMINE, L.D.

    2006-02-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

  12. Linking the soil moisture distribution pattern to dynamic processes along slope transects in the Loess Plateau, China.

    Science.gov (United States)

    Wang, Shuai; Fu, Bojie; Gao, Guangyao; Zhou, Ji; Jiao, Lei; Liu, Jianbo

    2015-12-01

    Soil moisture pulses are a prerequisite for other land surface pulses at various spatiotemporal scales in arid and semi-arid areas. The temporal dynamics and profile variability of soil moisture in relation to land cover combinations were studied along five slopes transect on the Loess Plateau during the rainy season of 2011. Within the 3 months of the growing season coupled with the rainy season, all of the soil moisture was replenished in the area, proving that a type stability exists between different land cover soil moisture levels. Land cover combinations disturbed the trend determined by topography and increased soil moisture variability in space and time. The stability of soil moisture resulting from the dynamic processes could produce stable patterns on the slopes. The relationships between the mean soil moisture and vertical standard deviation (SD) and coefficient of variation (CV) were more complex, largely due to the fact that different land cover types had distinctive vertical patterns of soil moisture. The spatial SD of each layer had a positive correlation and the spatial CV exhibited a negative correlation with the increase in mean soil moisture. The soil moisture stability implies that sampling comparisons in this area can be conducted at different times to accurately compare different land use types.

  13. Synthesis and antifungal activity of 2H-1,4-benzoxazin-3(4H)-one derivatives.

    Science.gov (United States)

    Śmist, Małgorzata; Kwiecień, Halina; Krawczyk, Maria

    2016-01-01

    A series of 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l) was easily synthesized by two-step process involving O-alkylation of 2-nitrophenols with methyl 2-bromoalkanoates and next "green" catalytic reductive cyclization of the obtained 2-nitro ester intermediates (3a-l). Further, 6,7-dibromo (5a-c) and N-acetyl (6) derivatives were prepared by bromination and acetylation of unsubstituted 2-alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-c). The novel compounds (3a-l, 4d-l, 5a-c and 6) were fully characterized by spectroscopic methods (MS, (1)H and (13)C NMR). 2-Alkyl-2H-1,4-benzoxazin-3(4H)-ones (4a-l, 5a-c and 6) were screened for antifungal activity. Preliminary assays were performed using two methods: in vitro against seven phytopathogenic fungi-Botrytis cinerea, Phythophtora cactorum, Rhizoctonia solani, Phoma betae, Fusarium culmorum, Fusarium oxysporum and Alternaria alternata-and in vivo against barley powdery mildew Blumeria graminis. The tested compounds displayed moderate to good antifungal activity at high concentration (200 mg L(-1)). The most potent compounds were 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a), 2-ethyl-7-fluoro-2H-1,4-benzoxazin-3(4H)-one (4g) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6), which completely inhibited the mycelial growth of seven agricultural fungi at the concentration of 200 mg L(-1) in the in vitro tests. Moreover, 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) and 4-acetyl-2-ethyl-2H-1,4-benzoxazin-3(4H)-one (6) were also screened for antifungal activity at concentrations of 100 mg L(-1) and 20 mg L(-1). In the concentration of 100 mg L(-1), the N-acetyl derivative (6) completely inhibited the growth of three strains of fungi (F. culmorum, P. cactorum and R. solani), while 2-ethyl-2H-1,4-benzoxazin-3(4H)-one (4a) completely inhibited only R. solani strain. At the concentration of 20 mg L(-1), compound 6 showed good activity only against P. cactorum strain (72%).

  14. Honing your knowledge skills a route map

    CERN Document Server

    Funes, Mariana

    1998-01-01

    New technology and organizational structures are transforming the workplace, but management skills have not yet caught up. Harnessing knowledge and using it as a competitive advantage is one of the key priorities of organizations today. Honing Your Knowledge Skills looks at how to define knowledge working and identifies the practical skills of knowledge management needed by line managers. This book shows you how to *handle information overload *become an expert *harness new ideas *turn knowledge into action * keep knowledge skills fresh. * understand IT resources and knowledge based systems.

  15. Atmospheric processes of organic pollutants over a remote lake on the central Tibetan Plateau: implications for regional cycling

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Yao, Tandong

    2017-01-01

    Atmospheric processes (air-surface exchange, and atmospheric deposition and degradation) are crucial for understanding the global cycling and fate of organic pollutants (OPs). However, such assessments over the Tibetan Plateau (TP) remain uncertain. More than 50 % of Chinese lakes are located on the TP, which exerts a remarkable influence on the regional water, energy, and chemical cycling. In this study, air and water samples were simultaneously collected in Nam Co, a large lake on the TP, to test whether the lake is a secondary source or sink of OPs. Lower concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were observed in the atmosphere and lake water of Nam Co, while the levels of polycyclic aromatic hydrocarbons (PAHs) were relatively higher. Results of fugacity ratios and chiral signatures both suggest that the lake acted as the net sink of atmospheric hexachlorocyclohexanes (HCHs), following their long-range transport driven by the Indian monsoon. Different behaviours were observed in the PAHs, which primarily originated from local biomass burning. Acenaphthylene, acenaphthene, and fluorene showed volatilization from the lake to the atmosphere, while other PAHs were deposited into the lake due to the integrated deposition process (wet/dry and air-water gas deposition) and limited atmospheric degradation. As the dominant PAH compound, phenanthrene exhibited a seasonal reversal of air-water gas exchange, which was likely related to the melting of the lake ice in May. The annual input of HCHs from the air to the entire lake area (2015 km2) was estimated as 1.9 kg yr-1, while input estimated for ∑ 15PAHs can potentially reach up to 550 kg yr-1. This study highlights the significance of PAH deposition on the regional carbon cycling in the oligotrophic lakes of the TP.

  16. Clay mineralogical and geochemical constraints on late Pleistocene weathering processes of the Qaidam Basin, northern Tibetan Plateau

    Science.gov (United States)

    Miao, WeiLiang; Fan, QiShun; Wei, HaiCheng; Zhang, XiYing; Ma, HaiZhou

    2016-09-01

    At the Qarhan Salt Lake (QSL) on the central-eastern Qaidam Basin, northern Tibetan Plateau, Quaternary lacustrine sediments have a thickness of over 3000 m and mainly composed of organic-rich clay and silty clay with some silt halite and halite. In this study, a 102-m-long sediment core (ISL1A) was obtained from the QSL. Combining with AMS 14C and 230Th dating, clay minerals and major-element concentrations of ISL1A were used to reconstruct the weathering process and trend of the QSL since late Pleistocene. The results reveal that the clay mineral from rocks, gneisses and schists of Eastern Kunlun Mountains on the south of the QSL. The abundance of illite mineral displays an opposite fluctuation trending with that of smectite, chlorite and kaolinite mineral in ISL1A, which is significantly different from the monsoon-controlled regions. Moreover, higher values of illite, kaolinite/chlorite and illite/chlorite ratios, and lower values of smectite, chlorite and kaolinite minerals occurred in 83-72.5 ka, 68.8-54 ka, 32-24 ka, corresponding to late MIS 5, late MIS 4, early MIS 3 and late MIS 3, respectively. These three phases were almost similarly changed with oxygen isotopes of authigenic carbonates and pollen records in ISL1A, which implies that stronger chemical weathering corresponds to higher effective moisture periods of source region in the Qaidam Basin. Based on chemical weathering index and (Al2O3-(CaO + Na2O)-K2O) diagram, chemical weathering degree in this study area takes a varying process from low to intermediate on the whole.

  17. [Growth process and diameter structure of Pinus tabulaeformis forest for soil and water conservation in Loess Plateau Hilly regions].

    Science.gov (United States)

    Zhang, Guang-Can; Liu, Xia; Zhou, Ze-Fu; Zhang, Shu-Yong; Liu, Gang; Chen, Jian

    2007-04-01

    Through stem analysis of sample trees, the biomass, growth process, and diameter structure of two 21 years old Pinus tabulaeformis forests growing on the shady and sunny slopes in Loess Plateau hilly and gully regions were investigated. The results showed that there were distinct differences between these two forests in their tree height, diameter at breast height (DBH), and timber volume. The forest biomass, growth status, and diameter structure on shady slope were superior to those on sunny slope. The fast-growing period of tree height all appeared in the period of 9-13 years, and after 13 years, the annual increment of tree height was larger in shady slope forest than in sunny slope forest, with the increment in the 21st year being 0.26 and 0.1, respectively. The DBH growth of the two forests was declined greatly after 13 years, but the decrement was obviously less in shady slope forest than in sunny slope forest. After 17 years, the annual increment of DBH growth was larger in shady slope forest than in sunny slope forest, with the values being 0.46 cm x a(-1) and 0.27 cm x a(-1), respectively in the 21st year. Before 13 years, there was little difference in the increment of timber production between the two forests, but the increment after 13 years was larger in shady slope forest than in sunny slope forest, with the values of 0.0023 m3 and 0.0015 m3, respectively in the 21st year. The summit of DBH distribution curve was all partial to left, but the skewness of shady slope forest (SK = 0.75) was lower than that of sunny slope forest (SK = 1.03), and the kurtosis of shady slope forest (K = 1.05) was higher than that of sunny slope forest (K = 0.94), indicating that sunny slope forest had a larger stand density than shady slope forest.

  18. On the optimal choice of wavelet function for multiscale honed surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Mezghani, S; Mansori, M El [Arts and Metiers ParisTech, LMPF, rue St Dominique - BP 508, 51006 Chalons-en-Champagne (France); Sabri, L [RENAULT S.A.S., Direction de la Mecanique/Direction de l' Ingenierie Process, Rueil Malmaison, Paris (France); Zahouani, H, E-mail: sabeur.mezghani@ensam.eu [Ecole Centrale de Lyon, LTDS UMR CNRS 5513, 36 avenue Guy de Collongue, 69131 Ecully Cedex (France)

    2011-08-19

    Multiscale surface topography characterization is mostly suited than standard approaches because it is more adapted to the multi-stage process generation. Wavelet transform represents a power tool to perform the multiscale decomposition of the surface topography in a wide range of wavelength. However, characterization results depend closely on the topography data acquisition instrument (resolution, height accuracy, sensitivity...) and also on the wavelet analysis method (discrete or continuous transform). In particular, the choice of wavelet function can have significant effect on the analysis results. In this paper, we present experimental work on a number of popular wavelets functions with the aim of finding wavelets that exhibit optimal description of honed surface features when continuous wavelet transform is used. We demonstrate that the regularity property of wavelet function has a significant influence on the characterization performances. This comparative study shows also that the Morlet wavelet is the more adapted wavelet basis function for multiscale characterization of honed surfaces using continuous wavelet transform.

  19. Investigation of the sources and processing of organic aerosol over the Central Mexican Plateau from aircraft measurements during MILAGRO

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2010-02-01

    Full Text Available Organic aerosol (OA represents approximately half of the submicron aerosol in Mexico City and the Central Mexican Plateau. This study uses the high time resolution measurements performed onboard the NCAR/NSF C-130 aircraft during the MILAGRO/MIRAGE-Mex field campaign in March 2006 to investigate the sources and chemical processing of the OA in this region. An examination of the OA/ΔCO ratio evolution as a function of photochemical age shows distinct behavior in the presence or absence of substantial open biomass burning (BB influence, with the latter being consistent with other studies in polluted areas. In addition, we present results from Positive Matrix Factorization (PMF analysis of 12-s High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS OA spectra. Four components were resolved. Three of the components contain substantial organic oxygen and are termed semivolatile oxygenated OA (SV-OOA, low-volatility OOA (LV-OOA, and biomass burning OA (BBOA. A reduced "hydrocarbon-like OA" (HOA component is also resolved. LV-OOA is highly oxygenated (atomic O/C~1 and is aged organic aerosol linked to regional airmasses, with likely contributions from pollution, biomass burning, and other sources. SV-OOA is strongly correlated with ammonium nitrate, Ox, and the Mexico City Basin. We interpret SV-OOA as secondary OA which is nearly all (>90% anthropogenic in origin. In the absence of biomass burning it represents the largest fraction of OA over the Mexico City basin, consistent with other studies in this region. BBOA is identified as arising from biomass burning sources due to a strong correlation with HCN, and the elevated contribution of the ion C2H4O2+ (m/z 60, a marker for levoglucosan and other primary BB species. WRF-FLEXPART calculated fire impact factors (FIF show good correlation with BBOA mass concentrations within the basin, but show location offsets in the far field

  20. Investigation of the sources and processing of organic aerosol over the Central Mexican Plateau from aircraft measurements during MILAGRO

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2010-06-01

    Full Text Available Organic aerosol (OA represents approximately half of the submicron aerosol in Mexico City and the Central Mexican Plateau. This study uses the high time resolution measurements performed onboard the NCAR/NSF C-130 aircraft during the MILAGRO/MIRAGE-Mex field campaign in March 2006 to investigate the sources and chemical processing of the OA in this region. An examination of the OA/ΔCO ratio evolution as a function of photochemical age shows distinct behavior in the presence or absence of substantial open biomass burning (BB influence, with the latter being consistent with other studies in polluted areas. In addition, we present results from Positive Matrix Factorization (PMF analysis of 12-s High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS OA spectra. Four components were resolved. Three of the components contain substantial organic oxygen and are termed semivolatile oxygenated OA (SV-OOA, low-volatility OOA (LV-OOA, and biomass burning OA (BBOA. A reduced "hydrocarbon-like OA" (HOA component is also resolved. LV-OOA is highly oxygenated (atomic O/C~1 and is aged organic aerosol linked to regional airmasses, with likely contributions from pollution, biomass burning, and other sources. SV-OOA is strongly correlated with ammonium nitrate, Ox, and the Mexico City Basin. We interpret SV-OOA as secondary OA which is nearly all (>90% anthropogenic in origin. In the absence of biomass burning it represents the largest fraction of OA over the Mexico City basin, consistent with other studies in this region. BBOA is identified as arising from biomass burning sources due to a strong correlation with HCN, and the elevated contribution of the ion C2H4O2+ (m/z 60, a marker for levoglucosan and other primary BB species. WRF-FLEXPART calculated fire impact factors (FIF show good correlation with BBOA mass concentrations within the basin, but show location offsets in the far field

  1. Abrasive selection of honing stone for TC11 titanium alloy hole honing%钛合金TC11深孔珩磨时油石磨料的选择

    Institute of Scientific and Technical Information of China (English)

    刘雁蜀; 彭海

    2011-01-01

    深孔珩磨钛合金难度很大.本研究针对TC11的特性,选用不同主磨料和辅磨料,按不同混合比例研制了15种珩磨油石,并用它们对TC11钛合金进行深孔珩磨对比试验.利用动态电阻应变仪、函数记录仪和测扭矩传感器进行了数据跟踪,绘制出了各混合磨料油石珩磨钛合金的磨削比和比磨削能图.结合示图分析,最终确定珩磨TC11的油石材料应选用GC70%+SA30%的混合磨料油石.这种混合磨料油石表现为珩磨去除量大,粘附少,磨削质量好.%Deep hole honing on Ti alloy TC - 11 is quite a difficult job. Based on the characteristics of TC -11, the authors selected different abrasive grits as principle and auxiliary abrasive and, with different proportion design, prepared 15 oil stone samples. Honing tests were carried out using dynamic resistance strain tester, X - Y plotter and torque sensor for date acquisition and processing. Diagrams of specific energy and grinding ratio of the honing stone samples were drawn and analyzed. The results showed that , the hybrid abrasive honing stone with GC (70% ) and SA ( 30% ) performed the highest removal rate , few load and the best honing quality .

  2. 大型双进给珩磨头的珩磨力数学模型研究∗%Research on Mathematical Model of Large Double Feed Honing Force

    Institute of Scientific and Technical Information of China (English)

    廖秋岩; 张龙波; 樊思敏

    2015-01-01

    For doing analysis of large double feed honing head movement and process,and using Newton's laws of mo-tion to force analysis in stages of honing head,honing head was analyzed on the stress distribution in the different processing process,thus established honing head in the process of different processing method of the pressure,axial pressure and the formulas of tangential stress.It provided a reference for the precise calculation of honing force,the strength and stiffness a-nalysis of the next step for honing head to lay a solid foundation.%对大型双进给珩磨头进行运动及加工过程分析,并运用牛顿运动定律对珩磨头进行分阶段受力分析,进而分析珩磨头在不同加工过程的受力情况,从而建立珩磨头在不同加工过程中法向力、切向力及轴向往复力的理论计算公式,为珩磨力的精确计算提供参考,并为大型珩磨头强度及刚度的进一步研究打下坚实基础。

  3. Analysis of land degradation processes on a tiger bush plateau in South West Niger using MODIS and LANDSAT TM/ETM+ data

    Science.gov (United States)

    Fiorillo, Edoardo; Maselli, Fabio; Tarchiani, Vieri; Vignaroli, Patrizio

    2017-10-01

    Remote sensing digital image analysis has been applied to monitor land clearing and degradation processes on a plateau covered by tiger bush near Niamey in South West Niger, where signs of severe landscape degradation due to fuelwood supply have been observed in the last decades. A MODIS NDVI dataset (2000-2015) and five LANDSAT images (1986-2012) were used to identify spatial and temporal dynamics and to emphasize areas of greater degradation. The study indicates that the land clearing found by previous investigations in the second part of the 20th century is still ongoing, with a decreasing trend of MODIS NDVI values recorded in the period 2000-2015. This trend appeared to be linked to an increase in bare soil areas that was demonstrated by analysis of LANDSAT SAVI images. The investigation also indicated that rates of degradation are stronger in more deteriorated areas like those located nearer Niamey; degradation patterns also tend to increase from the inner areas to the edges of the plateau. These results attest to the urgency to develop effective environmental preservation policies and find alternative solutions for domestic energy supply.

  4. 钕铁硼材料的功率超声珩磨加工试验研究%Nd-Fe-B Material Power Ultrasonic Honing Experimental Study

    Institute of Scientific and Technical Information of China (English)

    赵永娟; 潘玉田

    2011-01-01

    Aiming at the high hardness, high brittleness difficult processing characteristics of Nd-Fe-B material, use power ultrasonic honing method, design Nd-Fe-B power ultrasonic honing test device and carry on Nd-Fe-B material processing experiment, find the impact of Nd-Fe-B surface roughness and material removal rate factors by the orthogonal analysis of test data, and by comparing Nd-Fe-B surface SEM photographs of ultrasonic vibration honing and ordinary honing, prove that Nd-Fe-B material power ultrasonic honing can better improve Nd-Fe-B material processing quality than ordinary honing.%针对钕铁硼材料的高硬度、高脆性的难加工特性,利用功率超声珩磨加工方法,设计了钕铁硼功率超声珩磨加工试验装置,对钕铁硼进行加工试验,通过对试验数据的正交分析,找到了影响钕铁硼加工表面粗糙度和材料去除率的因素,并通过超声振动珩磨与普通珩磨加工钕铁硼材料的表面SEM照片,证明了钕铁硼材料的功率超声珩磨加工相比普通珩磨加工,能够提高钕铁硼材料的加工质量.

  5. Experiment and Design of Steel Thin Wall Cylinder Liner of Ultrasonic Honing and Its Research%超声珩磨钢质薄壁缸套的试验设计研究

    Institute of Scientific and Technical Information of China (English)

    乔培平

    2015-01-01

    This paper uses longitudinal vertical ultrasonic vibration honing device, respectively in MB4215Z type semi-automatic ho-ning machine and M4215 type honing machine to do three factors and four levels orthogonal test for steel thin wal cylinder liner and studies the characteristics of the ultrasonic honing oilstone, including super hard abrasive, grain size and binder on the surface roughness, dimensional accuracy, roundness, and the influence on honing efficiency. Results show that ultrasonic honing can be used to effectively solve the steel thin wal cylinder honing processing problems and a theoretical basis is provided for honing pro-cessing mild steel. This gives a certain guiding role to the actual production.%采用纵向振动立式超声珩磨装置,分别在MB4215Z型半自动珩磨机和M4215型珩磨机上,对钢制薄壁缸套基体进行三因素、四水平正交试验,研究了超声珩磨油石的特性,包括超硬磨料、粒度、结合剂等对表面粗糙度、尺寸精度、圆度和珩磨效率等的影响及影响程度。结果表明,超声珩磨可以有效地解决钢制薄壁缸套的珩磨加工难题,为珩磨加工软钢提供了理论依据,对实际生产具有一定的指导作用。

  6. Improvement and Analysis of One-Way Honing to Inner Ball Surface of Spherical Plain Bearing%关节轴承内圈球面单程珩磨分析与改进

    Institute of Scientific and Technical Information of China (English)

    蔡士源

    2014-01-01

    Based on the one-way honing process of inner surface of spherical plain bearing,the principle of one-way honing and finishing process are analyzed,and the principle defects of one-way honing and finishing are illustrated.A method of the spherical round-trip honing and super-finishing technique to replace the one-way honing is put for-ward,and the function of round-trip honing and working principle and characteristics of super-finishing are expoun-ded.%基于关节轴承内圈球面单程珩磨工艺,分析单程珩磨的原理和光整作用过程,说明了单程珩磨光整的原理性缺陷,提出了替代方法即球面双程珩磨和超精加工技术,并阐述了双程珩磨的作用和超精加工的工作原理及特点。

  7. Response of surface processes to climatic change in the dunefields and Loess Plateau of North China during the late Quaternary

    Science.gov (United States)

    Lu, H.; Mason, J.A.; Stevens, T.; Zhou, Y.; Yi, S.; Miao, X.

    2011-01-01

    This paper draws on recent optically stimulated luminescence (OSL) dating to evaluate the long-held assumption that dust accumulation rates in the Loess Plateau and the extent of active aeolian sand in the dunefields to the north have varied together over time, because both are controlled by the strength of the Asian monsoons and also possibly because the dunefields are proximal loess sources. The results show there is little evidence that high rates of loess accumulation coincided with well-dated episodes of extensive dune activity in the Mu Us, Otindag, and Horqin dunefields, at 11-8ka and 1-0ka. Explanations for the apparent lack of coupling include local variation in the trapping of dust and post-depositional preservation of the loess and dune sediments, in response to varying local environmental conditions. In addition, a substantial portion of the loess may be transported directly from source areas where dust emission has somewhat different climatic and geomorphic controls than aeolian sand activity within the dunefields. The results of this study cast doubt on the use of loess accumulation rate as a palaeoclimatic proxy at millennial timescale. The dunefield and loess stratigraphic records are interpreted as primarily recording changes in effective moisture at a local scale, but the timing of late Quaternary dune activity, along with a variety of other evidence, indicates that moisture changes in many of the drylands of northern China may not be in phase with precipitation in core regions of the Asian monsoons. ?? 2011 John Wiley & Sons, Ltd.

  8. Influence of geochemical processes on hydrochemistry and irrigation suitability of groundwater in part of semi-arid Deccan Plateau, India

    Science.gov (United States)

    Vasu, Duraisamy; Singh, Surendra Kumar; Tiwary, Pramod; Sahu, Nisha; Ray, Sanjay Kumar; Butte, Pravin; Duraisami, Veppangadu Perumal

    2017-02-01

    Major ion geochemistry was used to characterise the chemical composition of groundwater in part of semi-arid Deccan plateau region to understand the geochemical evolution and to evaluate the groundwater quality for irrigation. The study area comprises peninsular gneissic complex of Archean age, younger granites and basaltic alluvium. Forty-nine georeferenced groundwater samples were collected and analysed for major ions. The ionic sequence based on relative proportions was Na+ > Mg2+ > Ca2+ > SO4 2- > HCO3 - > Cl- > CO3 2- > BO3 3- > K+. High Na+, Mg2+ and Ca2+ were generally associated with basaltic alluvial formation, whereas pH, electrical conductivity (EC) and total dissolved salts (TDS) were found to be higher in granitic formations. High standard deviation for EC, TDS, Na+, Ca2+ and Mg2+ indicated the dispersion of ionic concentration throughout the study area. Four major hydrochemical facies identified were Na-Mg-HCO3 type; Mg-Na-HCO3 type; Na-Mg-Ca-SO4 and Mg-Na-Ca-SO4 type. The graphical plots indicated that the groundwater chemistry was influenced by rock-water interaction, silicate weathering and reverse ion exchange. Sodium-dominated waters might have impeded the hydraulic properties of soils as a result of long-term irrigation.

  9. Podcasting: An Effective Tool for Honing Language Students' Pronunciation?

    Science.gov (United States)

    Ducate, Lara; Lomicka, Lara

    2009-01-01

    This paper reports on an investigation of podcasting as a tool for honing pronunciation skills in intermediate language learning. We examined the effects of using podcasts to improve pronunciation in second language learning and how students' attitudes changed toward pronunciation over the semester. A total of 22 students in intermediate German…

  10. Comparison Between Honing and Reaming Honing in Machining Steering Valve Sleeve%转向器阀套内孔珩磨与铰珩工艺对比研究

    Institute of Scientific and Technical Information of China (English)

    杨筱蓉; 朱永伟; 朱振峰; 徐正选

    2013-01-01

    In this paper,the traditional honing is compared with the reaming homing from machining principle,processing parameters and machining results of the steering valve sleeve.Results show that:compared with traditional honing,reaming honing is characteristic of simple motion,high efficiency.perfect durability and rigdity,low cost and stable quality.This is the ixeal process for the batch process of the inner holes.%从加工原理、工艺参数、加工结果几个方面对加工转向器阀套使用的传统珩磨和铰珩工艺进行了对比研究.结果表明:铰珩相比传统珩磨工艺具有运动简洁高效、刀具耐用度高、刚性好、成本低、加工品质稳定、效率高等特点,是大批量加工内孔的理想工艺.

  11. Biomagnification of persistent organic pollutants along a high-altitude aquatic food chain in the Tibetan Plateau: Processes and mechanisms.

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Wang, Xiruo; Yao, Tandong

    2017-01-01

    Biomagnification of some persistent organic pollutants (POPs) has been found in marine and freshwater food chains; however, due to the relatively short food chains in high-altitude alpine lakes, whether trophic transfer would result in the biomagnification of POPs is not clear. The transfer of various POPs, including organochlorine pesticides and polychlorinated biphenyls (PCBs), along the aquatic food chain in Nam Co Lake (4700 m), in the central Tibetan Plateau, was studied. The POPs levels in the water, sediment and biota [plankton, invertebrates and fish (Gymnocypris namensis)] of Nam Co were generally low, with concentrations comparable to those reported for the remote Arctic. The composition profiles of POPs in the fish were different from that in the water, but similar to their food. DDEs, DDDs, PCB 138, 153 and 180 displayed significant positive correlations with trophic levels, with trophic magnification factors (TMFs) ranged between 1.5 and 4.2, implying these chemicals can undergo final biomagnification along food chain. A fugacity-based dynamic bioaccumulation model was applied to the fish with localized parameters, by which the simulated concentrations were comparable to the measured data. Modeling results showed that most compounds underwent net gill loss and net gut uptake; only when the net result of the combined gut and gill fluxes would be positive, bioaccumulation could eventually occur. The net accumulation flux increased with fish age, which was caused by the continuous increase of gut uptake by aged fish. Due to the oligotrophic condition, efficient food absorption is likely the key factor that influences the gut POPs uptake. Long residence times with half-lives up to two decades were found for the higher chlorinated PCBs in Gymnocypris namensis.

  12. The Hone Edge of the Carbide Cemented Drill Bit and the Measurement of Hone Edge Radius%硬质合金钻头刃口钝圆及其半径的测量

    Institute of Scientific and Technical Information of China (English)

    王弢; 周一丹; 张平

    2012-01-01

    指出了硬质合金钻头刃口钝圆对切削加工的影响,说明了硬质合金钻头刃口钝圆的重要性,简要介绍了刃口钝圆的方法及常规的测量方法,提出了在Matlab中用最小二乘法拟合的数据处理方法来获得刀口钝圆半径值.与传统测量方法相比,此方法避免了常规测量方法所产生的人为的不确定因素,减少了由于测量系统的精确度引起的误差,可以准确地判断是否达到钝化参数的要求,对优化刀具结构设计、提高切削性能、增加刀具使用寿命有重要的作用和实际意义.%The influence of hone edge radius of carbide drill bit during cutting was pointed out here, and the importance of hone edge was UlustratedAnd then,the measurement of hone edge and the way to measure were introduced briefly.The hone edge radius were acquired by a new data processing method of the least squares fitting, which can avoid the artificial uncertainties,reduce the errors caused by the accuracy of the measurement system in the conventional measurement methods,and it has an important significance for optimizing cutting tool structure design, improving cutting performance, and increasing tool life.

  13. Relative Roles of Deterministic and Stochastic Processes in Driving the Vertical Distribution of Bacterial Communities in a Permafrost Core from the Qinghai-Tibet Plateau, China.

    Science.gov (United States)

    Hu, Weigang; Zhang, Qi; Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; Stegen, James C; An, Lizhe; Feng, Huyuan

    2015-01-01

    Understanding the processes that influence the structure of biotic communities is one of the major ecological topics, and both stochastic and deterministic processes are expected to be at work simultaneously in most communities. Here, we investigated the vertical distribution patterns of bacterial communities in a 10-m-long soil core taken within permafrost of the Qinghai-Tibet Plateau. To get a better understanding of the forces that govern these patterns, we examined the diversity and structure of bacterial communities, and the change in community composition along the vertical distance (spatial turnover) from both taxonomic and phylogenetic perspectives. Measures of taxonomic and phylogenetic beta diversity revealed that bacterial community composition changed continuously along the soil core, and showed a vertical distance-decay relationship. Multiple stepwise regression analysis suggested that bacterial alpha diversity and phylogenetic structure were strongly correlated with soil conductivity and pH but weakly correlated with depth. There was evidence that deterministic and stochastic processes collectively drived bacterial vertically-structured pattern. Bacterial communities in five soil horizons (two originated from the active layer and three from permafrost) of the permafrost core were phylogenetically random, indicator of stochastic processes. However, we found a stronger effect of deterministic processes related to soil pH, conductivity, and organic carbon content that were structuring the bacterial communities. We therefore conclude that the vertical distribution of bacterial communities was governed primarily by deterministic ecological selection, although stochastic processes were also at work. Furthermore, the strong impact of environmental conditions (for example, soil physicochemical parameters and seasonal freeze-thaw cycles) on these communities underlines the sensitivity of permafrost microorganisms to climate change and potentially subsequent

  14. Quantification of the relative role of land-surface processes and large-scale forcing in dynamic downscaling over the Tibetan Plateau

    Science.gov (United States)

    Gao, Yanhong; Xiao, Linhong; Chen, Deliang; Chen, Fei; Xu, Jianwei; Xu, Yu

    2017-03-01

    Dynamical downscaling modeling (DDM) is important to understand regional climate change and develop local mitigation strategies, and the accuracy of DDM depends on the physical processes involved in the regional climate model as well as the forcing datasets derived from global models. This study investigates the relative role of the land surface schemes and forcing datasets in the DDM over the Tibet Plateau (TP), a region complex in topography and vulnerable to climate change. Three Weather Research and Forecasting model dynamical downscaling simulations configured with two land surface schemes [Noah versus Noah with multiparameterization (Noah-MP)] and two forcing datasets are performed over the period of 1980-2005. The downscaled temperature and precipitation are evaluated with observations and inter-compared regarding temporal trends, spatial distributions, and climatology. Results show that the temporal trends of the temperature and precipitation are determined by the forcing datasets, and the forcing dataset with the smallest trend bias performs the best. Relative to the forcing datasets, land surface processes play a more critical role in the DDM over the TP due to the strong heating effects on the atmospheric circulation from a vast area at exceptionally high elevations. By changing the vertical profiles of temperature in the atmosphere and the horizontal patterns of moisture advection during the monsoon seasons, the land surface schemes significantly regulate the downscaled temperature and precipitation in terms of climatology and spatial patterns. This study emphasizes the selection of land surface schemes is of crucial importance in the successful DDM over the TP.

  15. Research on the New Technology and System of Ultrasonic Honing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In recent years, the new technology of ultrasonic vibration cutting has been drawing general attention. And great advancement in theory and applications in production of the technology have been achieved. Ultrasonic vibration honing system developed in North China Institute of Technology and Nanjing University of Aeronautics and Astronautics of cast iron cylinder (47×97) and thin cylinder of 20# (86×95) has been successfully applied to productive experiment and the technological effect obtained is ideal...

  16. Research on the Dynamic Characteristics of Single Cavitation Bubble in Grinding Zone of the Power Ultrasonic Honing%功率超声珩磨磨削区单个空化泡动力特性的研究

    Institute of Scientific and Technical Information of China (English)

    郭策; 祝锡晶; 刘国东; 王建青

    2013-01-01

    空化效应是功率超声珩磨磨削区常见的物理现象,能够大幅提高超声珩磨的加工效率.建立了功率超声珩磨磨削区空化泡的动力学模型,采用4-5阶的Runge-Kutta方法,分析了空化泡的初始半径、超声频率、声压幅值、珩磨压力、珩磨头的回转速度对空化泡运动特性的影响.结果表明:超声波声压幅值与珩磨头的回转速度对磨削区空化泡运动特性影响较大,为进一步研究功率超声珩磨磨削区的空化效应提供了理论支持.%Cavitation effect can improve significantly processing efficiency of the ultrasonic honing,which happens in grinding zone of the power ultrasonic honing,is a common physical phenomena.The dynamic model of cavitation bubbles in the grinding zone of the power ultrasonic honing was established,with four-five levels of Runge-Kutta method.The effects of initial bubble radius,the frequency and pressure amplitude of the imposed ultrasonic field,honing pressure and the turning speed of honing head were numerically studied.It is shown that the amplitude of ultrasonic and the turning speed of honing head have greater effect than others.The results provide a theoretical support for cavitation effect in grinding zone of the power ultrasonic honing.

  17. Influence of short-term experimental warming on heat-water processes of the active layer in a swamp meadow ecosystem of the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    GuangSheng Liu; GenXu Wang

    2016-01-01

    Climate change is now evident in the Qinghai-Tibet Plateau (QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers (OTC) and the control manipulations were collected over a complete year. The results show that annual (2008) air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.

  18. Food-Chain Model of Grassland Degradation and Its Restoration Process in Northern Tibet Plateau: A Case Study in Nierong County

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wei; ZENG Yunying; LIU Shuzhen

    2006-01-01

    Based on the model of grassland climate ecological productivity, the process of grassland degradation and its restoration mechanism in northern Tibetan Plateau were discussed by the model of food-chain in which the environmental and human factors were corrected. The results of case study in Nierong County showed that:① the climate trend of becoming warmer, more droughts and gales were conflicted with the restoration of grassland degradation, even under level of perfect management the climate ecological productivity was declined from 89.3 kg/m2 of 1983 to 71.8 kg/m2 of 2003; ② from 1983 to 2003, the population increased fast, while the variation of livestock on hand was little, and the cost of its maintaining is rapid grassland degradation; ③ on the present condition of overgrazing, the livestock on hand can be maintained on the level of theoretical carrying capacity in 2033 by applying the mechanism of food-chain in grassland ecological system controlled with expected coefficients, so that to realize the policy of determining the quantity of livestock according to grass growth.

  19. Analyzing the transmission structures of long continuing current processes from negative ground flashes on the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Fan, Xiangpeng; Zhang, Guangshu; Wang, Yanhui; Li, Yajun; Zhang, Tong; Wu, Bin

    2014-03-01

    This paper presents a new overlap and progressive method using either a one-point charge model or a point dipole model for studying the electric field change data of lightning and tests the suitability of the proposed method by analyzing the slow electric field change of the long continuing current data from two negative ground flashes. The current measurements of the ground flashes are from the Composite Observing Experiment for Lightning project carried out in the Datong region of Qinghai Province, China, in 2009, obtained from field observations synchronized through high-precision GPS clocks at seven observation stations. Analysis shows that the time-averaged current can reach 800 A, and the current intensity relates to the height of the top of the return stroke before the continuing current process. The two current processes studied in this work neutralized a large amount of negative charge, 39.5C and 60.8C, respectively. The neutralized charges from the negative charge layer are typically at 2.5-4.7 km above ground. The intracloud transition of the positive leader is a complex process, and the horizontal propagation of the positive leader plays an important role in current duration as well as horizontally influencing the center of the electrical dipole moment with an obvious change of up to 3.0 km. The proposed analysis method is very useful compared to previous methods in terms of determining infinitesimal changes in long continuing currents. This work's new analysis method will help increase understanding of the fine physical processes of long continuing current processes.

  20. 珩磨头三维设计与仿真分析%3-D Design and Simulation Analysis of Honing Head

    Institute of Scientific and Technical Information of China (English)

    孙伏

    2013-01-01

    珩磨是对工件表面进行光整和精整的超精加工方法.在珩磨时,珩磨头的直线往复运动和旋转运动在工件表面上形成一定角度的、规则的交叉网纹,这种网纹是珩磨加工特有的.针对珩磨头要根据孔的大小进行设计,设计过程频繁,结构合理性以及运动参数的选择直接影响加工质量,以加工直径Φ40mm,长180mm的钢件孔的圆柱珩磨头为例进行了设计,用Pro/E软件进行参数化建模和运动学、动力学的仿真分析,观察其运行情况,得到相关数据,可提高设计效率和质量.%Honing is a super-precision process to surface of workpieces. In the honing, reciprocating and rotary of the honing head makes workpiece's surface form unique cross-textured. For some problem such as designed frequently according to hole size and influence of structure and kinematic parameters choice to process quality, parametric three-dimensional modeling, kinematics, dynamics simulation analysis applying Pro/E software are designed for example of cylindrical honing head in honing holes with diameter φ40mm and length 180mm. Watch its run and get data. Design efficient and quality is improved.

  1. Synthesis and characterization of new 3-(4,5-dihydro-5-arylisoxazol-3-yl-4-hydroxyquinolin-2(1H-ones and 3-(4-styrylisoxazolo[4,5-c]quinolin-4(5H-one derivatives

    Directory of Open Access Journals (Sweden)

    S. Sarveswari

    2016-09-01

    Full Text Available The 4-hydroxy-3-(3-arylacryloylquinolin-2(1H-ones were synthesized from 3-acetyl-4-hydroxyquinolin-2(1H-one by microwave assisted synthesis, which in turn converted into their corresponding 3-(4,5-dihydro-5-arylisoxazol-3-yl-4-hydroxyquinolin-2(1H-ones and 3-(4-styrylisoxazolo[4,5-c]quinolin-4(5H-one derivatives.

  2. Surface topography of cylindrical gear wheels after smoothing in abrasive mass, honing and shot peening

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, J; Pawlus, P [Rzeszow University of Technology, W Pola 2, 35-935 Rzeszow (Poland); Zelasko, W, E-mail: jmichals@prz.edu.pl [Technical School Complex at Lezajsk, Mickiewicza 67, 37-300 Lezajsk (Poland)

    2011-08-19

    The present paper presents the analysis of surface topography of gear teeth as the result of final machining processes. Teeth of multiple cylindrical gears shaped by grinding were smoothed in abrasive mass, honed or shot peened. The measurement of gears were made using coordinate measuring machine and 3D surface topography stylus instrument. The following deviations were studied; pitch deviation, total pitches deviations, variation of teeth thickness and deviation of gear radial run-out. Changes in teeth surface topography during machining process were determined. 3D surface topography parameters, surface directionality as well as areal autocorrelation and power spectral density functions were taken into consideration. As the results of the analysis, the best surface topography with regard to gear operational properties was recommended.

  3. Surface topography of cylindrical gear wheels after smoothing in abrasive mass, honing and shot peening

    Science.gov (United States)

    Michalski, J.; Pawlus, P.; Żelasko, W.

    2011-08-01

    The present paper presents the analysis of surface topography of gear teeth as the result of final machining processes. Teeth of multiple cylindrical gears shaped by grinding were smoothed in abrasive mass, honed or shot peened. The measurement of gears were made using coordinate measuring machine and 3D surface topography stylus instrument. The following deviations were studied; pitch deviation, total pitches deviations, variation of teeth thickness and deviation of gear radial run-out. Changes in teeth surface topography during machining process were determined. 3D surface topography parameters, surface directionality as well as areal autocorrelation and power spectral density functions were taken into consideration. As the results of the analysis, the best surface topography with regard to gear operational properties was recommended.

  4. Extrusion Honed Surface Characteristics of Inconel 625 Fabricated By EDM for Square Shape

    Directory of Open Access Journals (Sweden)

    N.L. Murali Krishna

    2014-07-01

    Full Text Available Extrusion Honing (EH is also known as Abrasive flow machining (AFM is an effective method that is used to deburr, clean, polish, remove recast layer and micro cracks by flowing pressurized semisolid abrasive laden visco-elastic media over those surfaces. Inconel 625 is one of the most difficult-to-cut materials because of its low thermal diffusive property, high hardness and high strength at elevated temperature. In this paper, the influence of the process parameters on surface roughness is investigated on Inconel 625 material of square shape fabricated by Electric discharge machining (EDM. The processed surfaces were measured and analyzed with the help of surface roughness tester and Scanning Electron Microscope (SEM. Results show a significant improvement in surface finish and EH/AFM is capable of removing the micro cracks and recast layer.

  5. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  6. 1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

    Science.gov (United States)

    Mielgo, Antonia

    2016-01-01

    Summary Asymmetric catalysis represents a very powerful tool for the synthesis of enantiopure compounds. In this context the main focus has been directed not only to the search for new efficient chiral catalysts, but also to the development of efficient pronucleophiles. This review highlights the utility and first examples of 1H-imidazol-4(5H)-ones and thiazol-4(5H)-ones as pronucleophiles in catalytic asymmetric reactions. PMID:27340482

  7. 1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis.

    Science.gov (United States)

    Mielgo, Antonia; Palomo, Claudio

    2016-01-01

    Asymmetric catalysis represents a very powerful tool for the synthesis of enantiopure compounds. In this context the main focus has been directed not only to the search for new efficient chiral catalysts, but also to the development of efficient pronucleophiles. This review highlights the utility and first examples of 1H-imidazol-4(5H)-ones and thiazol-4(5H)-ones as pronucleophiles in catalytic asymmetric reactions.

  8. Effect of a cold, dry air incursion on atmospheric boundary layer processes over a high-altitude lake in the Tibetan Plateau

    Science.gov (United States)

    Li, Zhaoguo; Lyu, Shihua; Wen, Lijuan; Zhao, Lin; Ao, Yinhuan; Wang, Shaoying

    2017-03-01

    High-altitude lakes are frequently exposed to extreme meteorological conditions, but the surface and atmospheric boundary layer (ABL) processes have received little attention under specific weather conditions. This study used the multi-source field data, re-analysis and remote sensing data to investigate the varying patterns and driving forces of the convective boundary layer (CBL) height over Ngoring Lake in the Tibetan Plateau (TP) before and after the cold air incursion. Daily cumulative surface heat flux and buoyancy flux over the land were markedly larger than those over the lake on a clear summer day, but an opposite pattern was observed accompanied by the cold air incursion. CBLs determined by the potential temperature thinned (depth < 100 m) over the lake in the daytime and thickened (400-600 m) at night on a clear day. Along with the arrival of the cold air, CBL rapidly thickened to 2280 m over the lake, exceeded than the maximum value at adjacent Madoi station. Cold air dramatically cooled the middle-upper atmosphere but the temperature of the lower atmosphere cooled down slowly, partly due to a sharp increase of sensible heat flux over the lake, both of which linked up to weaken the potential temperature gradient. Moreover, increasing wind speed and vertical wind shear further facilitated the buoyancy flux to exert higher heat convection efficiency. All of these factors acted together to cause the rapid growth of CBL over the lake. This investigation provided a more in-depth knowledge of boundary layer dynamics in the lake-rich region of the TP.

  9. Track of the Yellowstone hotspot: young and ongoing geologic processes from the Snake River Plain to the Yellowstone Plateau and Tetons

    Science.gov (United States)

    Morgan, Lisa A.; Pierce, Kenneth L.; Shanks, Pat; Raynolds, Robert G.H.

    2008-01-01

    This field trip highlights various stages in the evolution of the Snake River Plain–Yellowstone Plateau bimodal volcanic province, and associated faulting and uplift, also known as the track of the Yellowstone hotspot. The 16 Ma Yellowstone hotspot track is one of the few places on Earth where time-transgressive processes on continental crust can be observed in the volcanic and tectonic (faulting and uplift) record at the rate and direction predicted by plate motion. Recent interest in young and possible renewed volcanism at Yellowstone along with new discoveries and synthesis of previous studies, i.e., tomographic, deformation, bathymetric, and seismic surveys, provide a framework of evidence of plate motion over a mantle plume. This 3-day trip is organized to present an overview into volcanism and tectonism in this dynamically active region. Field trip stops will include the young basaltic Craters of the Moon, exposures of 12–4 Ma rhyolites and edges of their associated collapsed calderas on the Snake River Plain, and exposures of faults which show an age progression similar to the volcanic fields. An essential stop is Yellowstone National Park, where the last major caldera-forming event occurred 640,000 years ago and now is host to the world's largest concentration of hydrothermal features (>10,000 hot springs and geysers). This trip presents a quick, intensive overview into volcanism and tectonism in this dynamically active region. Field stops are directly linked to conceptual models related to hotspot passage through this volcano-tectonic province. Features that may reflect a tilted thermal mantle plume suggested in recent tomographic studies will be examined. The drive home will pass through Grand Teton National Park, where the Teton Range is currently rising in response to the passage of the North American plate over the Yellowstone hotspot.

  10. In-Process Inspection Study (IPIS) for Abrasive Machining (Honing)

    Science.gov (United States)

    1990-11-09

    Photonic Sensor Calibration Fixture 5-3 VOLTAGE vs DISPLACEMENT FOTONIC SENSOR USING A 2 MICROINCH SURFACE FINISH 11 10 9 8 7 S 6 -j 4 2 0...in Appendix VIII and presented graphically in Figures 5-6 through 5-8. SURFACE FINISH vs OUTPUT VOLTAGE FOTONIC SENSOR WITH VARIABLE SURFACE FINISHES...Finish Testing 5-7 SURFACE FINISH vs OUTPUT VOLTAGE FOTONIC SENSOR WITH VARIABLE SURFACE FINISHES AND A CONSTANT PROBE OFFSET 1211 CLEAN OIL FILM .02" 10

  11. Design of Keyhole Extrusion Honing Device Based on Fluid Magnetic Abrasive%基于液体磁性磨具的小孔挤压珩磨装置设计

    Institute of Scientific and Technical Information of China (English)

    孟强; 孙桓五; 吴正雨

    2013-01-01

    For the processing question of inside wall of spray hole and fuel injection pipe on the engine,a new kind of keyhole extrusion honing device based on fluid magnetic abrasive was designed.Structure composition and working principle of the device were introduced.Through extrusion honing experiment,the device is proved to have ideal results in the honing of hole.%针对发动机上的喷油孔、高压油管等小孔内壁加工困难的问题,设计了一种新型的基于液体磁性磨具的小孔挤压珩磨装置.介绍了该装置的结构和工作原理,通过挤压珩磨实验验证了该装置在珩磨小孔方面具有理想的效果.

  12. Gimme Shelter!: Doghouse Project Hones Construction Skills

    Science.gov (United States)

    Shackelford, Ray; Griffis, Kurt

    2007-01-01

    In Rover's House project, students practice planning, measurement, layout, and processing skills in building a doghouse. The project is more than a doghouse--it is a learning activity that helps students develop and enhance their ability to work with reinforced concrete, steel and wood studs, trusses, roofing materials and a variety of…

  13. Glacial lake evolution in the southeastern Tibetan Plateau and the cause of rapid expansion of proglacial lakes linked to glacial-hydrogeomorphic processes

    Science.gov (United States)

    Song, Chunqiao; Sheng, Yongwei; Ke, Linghong; Nie, Yong; Wang, Jida

    2016-09-01

    Glacial lakes, as an important component of the cryosphere in the southeastern Tibetan Plateau (SETP) in response to climate change, pose significant threats to the downstream lives and properties of people, engineering construction, and ecological environment via outburst floods, yet we currently have limited knowledge of their distribution, evolution, and the driving mechanism of rapid expansions due to the low accessibility and harsh natural conditions. By integrating optical imagery, satellite altimetry and digital elevation model (DEM), this study presents a regional-scale investigation of glacial lake dynamics across two river basins of the SETP during 1988-2013 and further explores the glacial-hydrogeomorphic process of rapidly expanding lakes. In total 1278 and 1396 glacial lakes were inventoried in 1988 and 2013, respectively. Approximately 92.4% of the lakes in 2013 are not in contact with modern glaciers, and the remaining 7.6% includes 27 (1.9%) debris-contact lakes (in contact with debris-covered ice) and 80 (5.7%) cirque lakes. In categorizing lake variations, we found that debris-contact proglacial lakes experienced much more rapid expansions (∼75%) than cirque lakes (∼7%) and non-glacier-contact lakes (∼3%). To explore the cause of rapid expansion for these debris-contact lakes, we further investigated the mass balance of parent glaciers and elevation changes in lake surfaces and debris-covered glacier tongues using time-series Landsat images, ICESat altimetry, and DEM. Results reveal that the upstream expansion of debris-contact proglacial lakes was not directly associated with rising water levels but with a geomorphological alternation of upstream lake basins caused by melting-induced debris subsidence at glacier termini. This suggests that the hydrogeomorphic process of glacier thinning and retreat, in comparison with direct glacial meltwater alone, may have played a dominant role in the recent glacial lake expansion observed across the

  14. Radiative plateau inflation

    CERN Document Server

    Ballesteros, Guillermo

    2016-01-01

    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflation with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  15. Discovery of 3,4-Dihydropyrimidin-2(1H)-ones As a Novel Class of Potent and Selective A2B Adenosine Receptor Antagonists.

    Science.gov (United States)

    Crespo, Abel; El Maatougui, Abdelaziz; Biagini, Pierfrancesco; Azuaje, Jhonny; Coelho, Alberto; Brea, José; Loza, María Isabel; Cadavid, María Isabel; García-Mera, Xerardo; Gutiérrez-de-Terán, Hugo; Sotelo, Eddy

    2013-11-14

    We describe the discovery and optimization of 3,4-dihydropyrimidin-2(1H)-ones as a novel family of (nonxanthine) A2B receptor antagonists that exhibit an unusually high selectivity profile. The Biginelli-based hit optimization process enabled a thoughtful exploration of the structure-activity and structure-selectivity relationships for this chemotype, enabling the identification of ligands that combine structural simplicity with excellent hA2B AdoR affinity and remarkable selectivity profiles.

  16. A Novel pseudo-Four-Component Domino Reaction for the Synthesis of Naphtho[2,1-b]furan-2(1H)-ones Using a Nanocatalyst.

    Science.gov (United States)

    Salami-Ranjbaran, Elmira; Khosropour, Ahmad R; Mohammadpoor-Baltork, Iraj; Moghadam, Majid; Tangestaninejad, Shahram; Mirkhani, Valiollah

    2015-08-10

    In this article, an original one-pot method is utilized to synthesize a variety of derivatives of naphtho[2,1-b]furan-2(1H)-one via a pseudo-four-component domino reaction of aryl aldehydes, acetic anhydride, hippuric acids, and 2-naphthols catalyzed by HSW@SPIONs. This reaction illustrates an array of attractive features including, with particular interest in this report, a convenient and unique process of creating and utilizing a powerful recyclable nanocatalyst.

  17. Enrichment of Mantle-derived Fluids in the Formation Process of Granitoids: Evidence from the Himalayan Granitoids around Kunjirap in the Western Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    姜耀辉; 凌洪飞; 蒋少涌; 周珣若; 芮行健; 杨万志

    2002-01-01

    Taking the Himalayan granitoids around Kunjirap in the western Qinghai-Tibet plateau as an example, the authors present in this paper the characteristics of the granitoids rich in mantle-derived fluid components and discuss their rock-forming mechanism. The research results indicate that the rock assemblage of the studied granitoids involves diopside syenite-diopside granite-biotite (monzonitic) granite, consisting mainly of K-feldspar, oligoclase, quartz, iron-phlogolite, diopside and edenite. The rocks are rich in mantle-derived fluid components of volatiles including F, alkali metal elements such as K, Na, Rb, Sr and Ba, and radiogenic heat-producing elements such as U and Th. They were generated by the influx of mantle-derived fluids into the lower crust to give rise to partial melting during the lithosphere thinning in the Qinghai-Tibet plateau.

  18. The Third Pole Environment Programme (TPE): A new base for the processes study of atmospheric physics and environment over the Tibetan Plateau and surrounding regions

    Science.gov (United States)

    Ma, Yaoming

    2016-04-01

    The Tibetan Plateau, with the most prominent and complicated terrain on the globe and an elevation of more than 4000 m on average above sea leave (msl), is often called the "Third Pole" due to its significance parallel with Antarctica and the Arctic. The exchange of energy, water vapor and some greenhouse gases between land surface and atmosphere over the Tibetan Plateau and the surrounding regions play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. Supported by the Chinese Academy of Sciences and some international organizations, a Third Pole Environment (TPE) Research Platform (TPEP) is now implementing over the Tibetan Plateau and surrounding region. The background of the establishment of the TPEP, the establishing and monitoring plan of long-term scale (5-10 years) of the TPEP will be shown firstly. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes, CO2 flux and evapotranspiration (ET) partitioning (diurnal variation, inter-monthly variation and vertical variation etc), aerosol optical properties between southern and northern sides of the Himalayas, the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this study.

  19. Plateau Indian Ways with Words

    Science.gov (United States)

    Monroe, Barbara

    2009-01-01

    The indigenous rhetoric of the Plateau Indians continues to exert a discursive influence on student writing in reservation schools today. Plateau students score low on state-mandated tests and on college writing assignments, in large part because the pervasive personalization of Plateau rhetoric runs counter to the depersonalization of academic…

  20. Greening the Plateau

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Located on the world’s largest plateau, Tibet Autonomous Region in China’s southwest has an average elevation of 4,000 meters. Tibet’s diverse natural landscapes, including snow-capped mountains, vast pastures and virgin forests, combined with its

  1. 珩磨机控制系统设计与实现%Design and Implementation of the Honing Machine Control System

    Institute of Scientific and Technical Information of China (English)

    盛维杰; 李维嘉

    2013-01-01

    According to the honing machine lathe process principle and the control requirements, we design the honing machine control system to achieve precise motion control. This paper describes design ideas of the STM32 machine tool controller of Cortex - M4 architecture,as well as u-sing the Master - slave CANopen industrial buses to build system communication and control networks.%根据珩磨机车床加工工艺原理和控制要求,设计珩磨机控制系统,实现了对珩磨机的精确运动控制.阐述了利用Cortex-M4架构的STM32开发机床控制器的设计思路以及利用主从式CAN-open工业总线构建系统通讯控制网络.

  2. Pd/C-mediated synthesis of α-pyrone fused with a five-membered nitrogen heteroaryl ring: A new route to pyrano[4,3-c]pyrazol-4(1H-ones

    Directory of Open Access Journals (Sweden)

    Dhilli Rao Gorja

    2009-11-01

    Full Text Available Pd/C-mediated alkynylation of 5-iodo-pyrazole-4-carboxylic acid, involving the first regioselective construction of α-pyrone ring on a pyrazol moiety via tandem coupling–cyclization process, has been developed to afford pyrano[4,3-c]pyrazol-4(1H-one in a single pot.

  3. Institute of Tibetan Plateau Research

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The Tibetan Plateau (Qinghai-Xizang Plateau)is a unique geological-geographical unit on Earth, an ideal region for studies into the formation and evolution of the lithosphere and the dynamic mechanism of the earth crust. The uplifting of the Plateau exerts profound influence upon the evolution and differentiation of the natural environment of the plateau itself, its adjacent regions and the Northern Hemisphere. As a unique natural geographical unit, the Plateau holds a special status in the whole globe due to its special natural environment and ecosystems, which is also in close relation to global environmental change.The significance of the Plateau research should be recognized not only in the fundamental research fields of geo-sciences and biology, but also in its application to resource exploitation, environmental protection and sustainable development of the Plateau region.

  4. Modularity of the anthropoid dentition: Implications for the evolution of the hominin canine honing complex.

    Science.gov (United States)

    Delezene, Lucas K

    2015-09-01

    In most anthropoid primates, the maxillary canine, mandibular canine, and mesial mandibular premolar form a functional complex that hones the canines. Characters in functional complexes are predicted to covary genetically, which constrains their evolutionary independence. As a result of substantial changes to canine and honing premolar size and shape, hominins are characterized by the apomorphic loss of canine honing. In early hominins, changes in canine and 'honing' premolar size and shape appear to have been uncoordinated, which is unexpected if there is strong genetic covariation coupling these teeth. Using the pattern and magnitude of phenotypic dental size covariation in extant anthropoids, results of this study indicate that certain dimensions of the anthropoid honing complex are characterized by strong size covariation within species and that canine and honing premolar size have evolved in a coordinated manner in both males and females, which undermines arguments that the complex is selectively important only in males. Further, there is no evidence for negative or strong positive covariance between canine and either incisor or postcanine size. If patterns of phenotypic covariation reflect genetic covariation, this suggests that canine reduction was unlikely to have been a dependent change associated with the development of postcanine megadontia or incisor reduction.

  5. Comparison and validation of Logistic Regression and Analytic Hierarchy Process models of landslide susceptibility in monoclinic regions. A case study in Moldavian Plateau, N-E Romania

    Science.gov (United States)

    Ciprian Margarint, Mihai; Niculita, Mihai

    2014-05-01

    The regions with monoclinic geological structure are large portions of earth surface where the repetition of similar landform patterns is very distinguished, the scarps of cuestas being characterized by similar values of morphometrical variables. Landslides are associated with these scarps of cuestas and consequently, a very high value of landslide susceptibility can be reported on its surface. In these regions, landslide susceptibility mapping can be realized for the entire region, or for test areas, with accurate, reliable, and available datasets, concerning multi-temporal inventories and landslide predictors. Because of the similar geomorphologic and landslide distribution we think that if any relevance of using test areas for extrapolating susceptibility models is present, these areas should be targeted first. This study case try to establish the level of usability of landslide predictors influence, obtained for a 90 km2 sample located in the northern part of the Moldavian Plateau (N-E Romania), in other areas of the same physio-geographic region. In a first phase, landslide susceptibility assessment was carried out and validated using logistic regression (LR) approach, using a multiple landslide inventory. This inventory was created using ortorectified aerial images from 1978 and 2005, for each period being considered both old and active landslides. The modeling strategy was based on a distinctly inventory of depletion areas of all landslide, for 1978 phase, and on a number of 30 covariates extracted from topographical and aerial images (both from 1978 and 2005 periods). The geomorphometric variables were computed from a Digital Elevation Model (DEM) obtained by interpolation from 1:5000 contour data (2.5 m equidistance), at 10x10 m resolution. Distance from river network, distance from roads and land use were extracted from topographic maps and aerial images. By applying Akaike Information Criterion (AIC) the covariates with significance under 0.001 level

  6. Exploration in Newnes Plateau, NSW

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P.; McQuade, C. [Pasminco Port Pirie Smelter, NSW (Australia)

    1999-06-01

    Underground coal mining operations in the Western Coalfields of NSW extend into the Newnes Plateau area. The Newnes Plateau area is known for its floral diversity and distinctive topography. A quantitative flora assessment concerning rehabilitation performance of exploration sites was undertaken to refine the environmental component of the exploration process and identify practices that may assist in an improved rate of regeneration within disturbed areas. This article briefly summarises the method and key outcomes of the study, undertaken as part of an Honours Degree program. Surveys of sites showed that plant height was reduced due to vehicle traffic compacting soil, and this also led to a reduced number of plant species and a reduced number of seedlings germinating. Percentage litter cover was found to be positively correlated with the number of species on the sites and the percent plant cover of the regenerating vegetation, shallow surface ripping is recommended to relieve soil compaction. Seeds should be collected from exploration sites prior to disturbance, particularly of species like Banksia and Haken that retain their seed on the plant. Seed should then be dispersed after work has finished. 1 fig., 2 photos.

  7. A facile microwave assisted one-pot synthesis of novel 1-methylhexahydroquinazolin-5(6H-ones and bis-1-methylhexahydroquinazolin-5(6H-ones

    Directory of Open Access Journals (Sweden)

    Madhusudhan Saha

    2011-03-01

    Full Text Available Novel hexahydroquinazolin-5(6H-ones 3a-j have been synthesized in good yields by the reaction of enaminones 2a-b with primary amines and formaldehyde under the influence microwaves. Enaminones 2a-b have also been reacted with diamines and formaldehyde under similar conditions resulting in hitherto unreported bis- hexahydroquinazolin-5(6H-ones 4a-d and 5a-d. The structures of the molecules have been established with the help of spectral and analytical data.

  8. [Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)].

    Science.gov (United States)

    Zhu, Rui-Juan; Rao, Xin-Feng; Wei, Deng-Bang; Wang, Duo-Wei; Wei, Lian; Sun, Sheng-Zhen

    2012-04-25

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDH1 and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P 0.05); (3) mRNA level and enzymatic activity of MDH1 was significantly lower than those of MDH2 in the pika liver (P 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.

  9. Extrude Honing Abrasive Slurry and Its Honing Experiments for Fuel Jet Nozzle%喷油嘴微喷孔挤压研磨液及其试验研究

    Institute of Scientific and Technical Information of China (English)

    黄颖; 张向军; 李勇; 李晓民

    2011-01-01

    The abrasive flow machining has become a key process for the advanced diesel engines to finish the final surface of fuel injector nozzle. Abrasive slurry was compounded by the method of oil-water emulsion. According to the principles of abrasive flow machining, a kind of abrasive slurry with good performance in suspension and cutting was explored and compounded, whose abrasive particles are brown alumina, and particle size range is 0. 4~50 μm. In addition, a test -bed was built for extruding honing the fuel injector nozzle. Then, the variations of the flow coefficient were measured and a series of the process parameters involved in the extruding honing technology for the fuel injector nozzle were studied experimentally. The injector nozzles were extruding honed under different times and pressures. With the increase of processing time, the effect was gradually saturated. With the increese of pressure, the wear of the device was serious. Tes-ting results indicated that 5 min and 10 Mpa are the best process parameters. The fuel injector nozzles were reamed in the process but didn't exceed 2%.%挤压研磨工艺已经成为高端柴油机喷油嘴微喷孔加工的最终表面成形的关键工序.根据磨料流加工的原理采用油水乳浊液的方式,配制了具有良好分散性能和切削性能的研磨剂,其磨料颗粒为棕刚玉,粒度范围0.4~50 μm,搭建了喷油嘴微喷孔挤压研磨的试验台,测量其流量因数的变化,对喷油嘴微喷孔挤压研磨工艺中的时间、压力因素进行了试验研究.随加工时间增加,研磨效果趋于饱和,随加工压力增加,对设备磨损加剧,试验结果表明,加工时间5 min,加工压力10 MPa为最佳工艺参数.挤压研磨过程中,造成了喷油嘴微喷孔孔径的扩大,但是不超过2%.

  10. Evaluation and Comparison of the Processing Methods of Airborne Gravimetry Concerning the Errors Effects on Downward Continuation Results: Case Studies in Louisiana (USA and the Tibetan Plateau (China

    Directory of Open Access Journals (Sweden)

    Qilong Zhao

    2017-05-01

    Full Text Available Gravity data gaps in mountainous areas are nowadays often filled in with the data from airborne gravity surveys. Because of the errors caused by the airborne gravimeter sensors, and because of rough flight conditions, such errors cannot be completely eliminated. The precision of the gravity disturbances generated by the airborne gravimetry is around 3–5 mgal. A major obstacle in using airborne gravimetry are the errors caused by the downward continuation. In order to improve the results the external high-accuracy gravity information e.g., from the surface data can be used for high frequency correction, while satellite information can be applying for low frequency correction. Surface data may be used to reduce the systematic errors, while regularization methods can reduce the random errors in downward continuation. Airborne gravity surveys are sometimes conducted in mountainous areas and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08-derived gravity data contaminated with the synthetic errors. The estimated systematic errors generated by the method are close to the simulated values. In addition, we study the relationship between the downward continuation altitudes and the

  11. Research progress in erosion-type nonpoint source poLLution process simuLationof the Loess PLateau%黄土高原水土流失型非点源污染过程模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    吴磊; 马孝义

    2015-01-01

    Loss of nitrogen and phosphorus in soil and water loss area of the Loess Plateau not only reduces the utilization rate of fertilizer,but also is a potential threat to aquatic environments.This study takes the typicality of soil and nutrient loss in the Lo-ess Plateau Region as a starting point to deeply analyse and systematically summarize the basic status of the Loss Plateau,the re-search progress of hydrological process,soil erosion,erosion-type nonpoint source pollution and its control strategies of the Loess Plateau.Aiming at the few existing studies on the Loess Plateau,the key research directions of nonpoint source pollution in the Loess Plateau for the future were proposed,such as the loss mechanism of nonpoint source pollution,the load estimation method of nonpoint source pollution in the Loess Plateau,the coupled model of water,sediment and pollution in the Loess Plateau,the combined application of 3S technology and control strategies of erosion-type nonpoint source pollution in the Loess Plateau etc.This re-sult may provide reference for studying the modeling process of erosion-type nonpoint source pollution in the Loess Plateau.%黄土高原严重的水土流失造成了土壤氮磷流失,不仅降低了化肥的利用率,而且对水环境造成了潜在威胁。从黄土高原区水土与养分流失的典型性入手,剖析和总结了黄土高原区基本概况、水文过程、土壤侵蚀、水土流失型非点源污染过程模拟及防控策略等的研究进展。针对目前黄土高原区尤其是黄土丘陵沟壑区非点源污染研究较少,提出了未来黄土高原地区非点源污染的研究方向与建议:黄土区非点源污染物流失机理,非点源污染负荷估算方法,流域水、沙、污染物耦合模型以及3S 技术与流域非点源污染防控决策耦合应用等。

  12. Podcasting: An Effective Tool for Honing Language Students’ Pronunciation?

    Directory of Open Access Journals (Sweden)

    Lara Ducate

    2001-10-01

    Full Text Available This paper reports on an investigation of podcasting as a tool for honing pronunciation skills in intermediate language learning. We examined the effects of using podcasts to improve pronunciation in second language learning and how students’ attitudes changed toward pronunciation over the semester. A total of 22 students in intermediate German and French courses made five scripted pronunciation recordings throughout the semester. After the pronunciation recordings, students produced three extemporaneous podcasts. Students also completed a pre- and post-survey based on Elliott’s (1995 Pronunciation Attitude Inventory to assess their perspectives regarding pronunciation. Students’ pronunciation, extemporaneous recordings, and surveys were analyzed to explore changes over the semester. Data analysis revealed that students’ pronunciation did not significantly improve in regard to accentedness or comprehensibility, perhaps because the16-week long treatment was too short to foster significant improvement and there was no in-class pronunciation practice. The podcast project, however, was perceived positively by students, and they appreciated the feedback given for each scripted recording and enjoyed opportunities for creativity during extemporaneous podcasts. Future studies might seek to delineate more specific guidelines or examine how teacher involvement might be adapted to the use of podcasts as a companion to classroom instruction.

  13. Synthesis, spectral characterization and larvicidal activity of acridin-1(2H)-one analogues

    Science.gov (United States)

    Subashini, R.; Bharathi, A.; Roopan, Selvaraj Mohana; Rajakumar, G.; Abdul Rahuman, A.; Gullanki, Pavan Kumar

    Acridin-1(2H)-one analogue of 7-chloro-3,4-dihydro-9-phenyl-2-[(pyridine-2yl) methylene] acridin-1(2H)-one, 5 was prepared by using 7-chloro-3,4-dihydro-9-phenylacridin-1(2H)-one, 3 and picolinaldehyde, 4 in the presence of KOH at room temperature. These compounds were characterized by analytical and spectral analyses. The purpose of the present study was to assess the efficacy of larvicidal and repellent activity of synthesized 7-chloro-3,4-dihydro-9-phenyl-acridin-1(2H)-one analogues such as compounds 3 and 5 against the early fourth instar larvae of filariasis vector, Culex quinquefasciatus and Japanese encephalitis vector, Culex gelidus (Diptera: Culicidae). The compound exhibited high larvicidal effects at 50 mg/L against both the mosquitoes with LC50 values of 25.02 mg/L (r2 = 0.998) and 26.40 mg/L (r2 = 0.988) against C. quinquefasciatus and C. gelidus, respectively. The 7-chloro-3,4-dihydro-9-phenyl-acridin-1(2H)-one analogues that are reported for the first time to our best of knowledge can be better explored for the control of mosquito population. This is an ideal ecofriendly approach for the control of Japanese encephalitis vectors, C. quinquefasciatus and C. gelidus.

  14. Application of Reaming Honing Technology in Valve Sleeve of Automobile Steering Gear%铰珩工艺在汽车转向器阀套中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘晓石

    2012-01-01

    A single - pass honing technology with super hard abrasive, named reaming honing technology, is used to solve the Sow accuracy and efficiency caused by the traditional honing technology which is used to machine the valve sleeve of automobile steering gear. The fixture and cutter proposal is given according to the machining characters of the valve sleeve, and the orthogonal test is used to investigate the effects of the reaming honing parameters on the machining performance. The reaming honing technology with the optimized parameters proves itself to solve the accuracy problem in the machining of valve sleeve effectively, as a result the match grinding processing is cancelled and the machining efficiency is improved.%针对传统珩磨工艺在汽车转向器阀套加工中存在的精度不足和效率不高问题,引入一种单冲程超硬磨料珩磨孔加工技术,即铰珩工艺.根据阀套的加工特点,设计相应的夹具和刀具方案,并通过正交试验法研究铰珩工艺参数对加工性能的影响.参数经过优化的铰珩工艺,有效解决了阀套内孔加工的精度问题,取消了配磨工序,提高了加工效率.

  15. Concentration and chiral signature of chlordane in soils and sediments of the Central Tibetan Plateau, China: Transformation in the surficial process.

    Science.gov (United States)

    Yuan, Guo-Li; Wu, Ming-Zhe; Sun, Yong; Li, Jun; Han, Peng; Wang, Gen-Hou

    2015-11-01

    The fraction of trans-chlordane (TC) in chlordane was used to indicate racemic degradation while the enantiomer fractions (EFs) indicated enantioselective depletion. In 44 soils of the Central Tibetan Plateau, the fractions of TC ranged from 0.368 to 0.411. The EFs ranged from 0.174 to 0.696 for TC and from 0.483 to 0.672 for cis-chlordane (CC). (-) enantiomer excess (ee) was found to be 80.0% in the soils for TC and (+) ee was 86.5% for CC. The fraction of TC changed with the clay content while the EFs changed with the soil organic carbon. Meanwhile, the fractions of TC and the EFs were determined for the surficial sediments in Yamzhog Yumco Lake, which were compared with those in the soils at its catchment area. The composition and chiral signature of chlordane did not vary between soils and sediments. Our results will help to elucidate the transformation of chlordane in soils and in surficial transport.

  16. Modeling and analysis of grinding force in ultrasonic honing considering the scale effect

    Directory of Open Access Journals (Sweden)

    Linzheng Ye

    2016-01-01

    Full Text Available To research the power ultrasonic honing mechanism at the micro scale, the scale effect is considered and the strain gradient plasticity theory based on the dislocation mechanism (MSG is applied to establish the model of a whetstone grinding force, and the simulation analysis is conducted. Results show: the grinding force will increase when the scale effect is considered; the main influence parameter is honing depth on the grinding force; the grinding force increases nonlinearly with the continued reduce of honing depth after which decreases to 1.4 μm, which decreases slightly with the increase of the relative velocity of a whetstone. So the material becomes difficult to remove at the micro scale.

  17. 3,3′-Oxybi[isobenzofuran-1(3H-one

    Directory of Open Access Journals (Sweden)

    Wenkuan Li

    2009-10-01

    Full Text Available The title compound, C16H10O5, consists of two isobenzofuran-1(3H-one moieties which are linked by a bridging O atom. The two halves of the molecule display approximate non-crystallographic mirror symmetry. The dihedral angle between the two isobenzofuran-1(3H-one ring systems is 53.18 (6 Å. Two chiral carbon centres are observed in the compound, but their absolute configurations could not be determined. In the crystal structure, intermolecular C—H...O hydrogen bonds link molecules into zigzag chains along c. Additional C—H...O interactions connect adjacent chains.

  18. Synthesis of 3-{4-[4-(Benzylideneaminobenzenesulfonyl]- phenyl}-2-phenylquinazolin-4(3H-one

    Directory of Open Access Journals (Sweden)

    Sunil Manohar Babu

    2009-01-01

    Full Text Available The present work describes the synthesis of a Schiff base, 3-{4-[4-(benzylideneamino benzenesulfonyl]phenyl}-2-phenylquinazolin-4(3H-one from a novel quinazolinone, 3-[4-(4 aminobenzenesulfonylphenyl]-2-phenylquinazolin-4(3H-one. The quinazolinone was prepared by reacting 2-phenyl-4H-3,1 benzoxazin-4-one with dapsone. The structure of the synthesized Schiff base is confirmed by IR, 1H NMR, 13C NMR, MS and elemental analysis.-

  19. Synthesis of spiro[isoindole-1,5’-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction

    Science.gov (United States)

    Cirmi, Santa; Mancuso, Raffaella; Nicolò, Francesco; Lanza, Giuseppe; Legnani, Laura; Campisi, Agata; Chiacchio, Maria A; Navarra, Michele; Gabriele, Bartolo

    2016-01-01

    A series of spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9–22 μM. Biological tests suggest that the antitumor activity could be linked to the inhibition of the protein–protein p53-MDM2 interaction. Docking measurements support the biological data. PMID:28144352

  20. Synthesis of spiro[isoindole-1,5’-isoxazolidin]-3(2H-ones as potential inhibitors of the MDM2-p53 interaction

    Directory of Open Access Journals (Sweden)

    Salvatore V. Giofrè

    2016-12-01

    Full Text Available A series of spiro[isoindole-1,5-isoxazolidin]-3(2H-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9–22 μM. Biological tests suggest that the antitumor activity could be linked to the inhibition of the protein–protein p53-MDM2 interaction. Docking measurements support the biological data.

  1. Magnetotelluric sounding results in eastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    马晓冰; 孔祥儒; 刘宏兵; 闫永利

    2001-01-01

    The results of Zayu-Qingshuihe MT sounding profile carried out in eastern Tibetan Plateau are presented in this paper. Using 2-D RRI method, the resistivity distribution with depth is obtained along the profile. It is featured by the resistivity zones in the horizontal direction and layers in the vertical direction. The Bangong-Nujiang suture zone and Jinshajiang suture zone are both important electrical conductivity-separating zones in the plateau, and the former is a zone with relatively low resistivity while the latter is an electrical conductivity gradient zone. The highly electrical conductive bodies in the mid and lower crust of northern Qiangtang and Bayan Har Terrain might be caused by regional melting due to shear heating during the process of subduction in tectonic evolution.

  2. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  3. Posterior bicondylar tibial plateau fractures.

    Science.gov (United States)

    Carlson, DuWayne A

    2005-02-01

    To present a case series of patients with posterior bicondylar tibial plateau fractures treated by direct fracture exposure and fixation through dual incisions. Retrospective clinical study. Level 1 trauma centers. Eight patients were identified that had posterior bicondylar tibial plateau fractures. Two patients had depressed posterolateral tibial plateau fractures with contained defects and did not have direct fracture exposure. One patient died of medical problems leaving 5 patients who underwent direct fracture exposure, reduction, and fixation. Posteromedial followed by posterolateral open reduction and internal fixation of posterior bicondylar tibial plateau fractures. At 6 to 24 months follow-up (mean 13 months), all patients returned to near full activities, each with aching after prolonged standing (8-hour shift). Range of motion averaged 2 degrees to 121 degrees of flexion. Three of 5 returned to manual labor jobs; the others were not employed at the time of injury. Posterior bicondylar tibial plateau fractures have a high association with lateral meniscal pathology and can be associated with anterior cruciate ligament injury. Reduction of the posterior plateau condyles is easiest with the knee in full extension. Flexion contractures can be a problem, and patients should be encouraged to regain/maintain knee extension. The dual-incision approach to these challenging fractures can result in good to excellent knee function for these patients.

  4. Domino [Pd]-Catalysis: One-Pot Synthesis of Isobenzofuran-1(3H)-ones.

    Science.gov (United States)

    Mahendar, Lodi; Satyanarayana, Gedu

    2016-09-02

    An efficient domino [Pd]-catalysis for the synthesis of isobenzofuran-1(3H)-ones is presented. The strategy shows broad substrate scope and is amenable to o-bromobenzyl tertiary/secondary/primary alcohols. Significantly, the method was applied to the synthesis of antiplatelet drug n-butyl phthalide and cytotoxic agonist 3a-[4'-methoxylbenzyl]-5,7-dimethoxyphthalide.

  5. 4-Acetyl-2-hydroxy-2,5-dimethylfuran-3(2H-one

    Directory of Open Access Journals (Sweden)

    Chiaki Akazaki

    2016-10-01

    Full Text Available The facile synthesis of 4-acetyl-2-hydroxy-2,5-dimethylfuran-3(2H-one (4 was achieved by the Mn(OAc3-mediated aerobic oxidation of 2,4-pentanedione or the direct reaction of Mn(acac3 in AcOH-TFE at room temperature under a dried air stream.

  6. 5-Dimethylamino-1-phenylchromeno[2,3-c]pyrazol-4(1H-one

    Directory of Open Access Journals (Sweden)

    Wolfgang Holzer

    2010-11-01

    Full Text Available The title compound was prepared by treatment of 5-fluoro-1-phenylchromeno [2,3-c]pyrazol-4(1H-one with aqueous dimethylamine. Detailed spectroscopic data (1H NMR, 13C NMR, 15N NMR, IR, MS are presented.

  7. Friday Forum and the AICPA Core Competency Framework: Honing Students' Personal Competencies

    Science.gov (United States)

    Johnson, Grace F.

    2013-01-01

    This paper shares one learning technique for honing undergraduate students' personal competencies. The senior accounting capstone course at a small Midwestern private liberal college includes a weekly seminar series, called the Friday Forum, where students and practitioners meet to discuss a current professional accounting article. Since Spring…

  8. 功率超声珩磨单颗磨粒耦合颤振模型%The Model of Single Abrasive Coupling Flutter During Power Ultrasonic Honing

    Institute of Scientific and Technical Information of China (English)

    张小强; 祝锡晶; 王建青; 王静

    2013-01-01

    Flutter,a dynamic and severe self-excited vibration easily to produce in power ultrasonic honing,is one of the important factors that affect the processing quality of the workpiece and the efficiency of the machine tool.In the basis of study in mechanism of power ultrasonic honing,choosing single abrasive and workpiece as research objects,respectively established the physical and mathematical of power ultrasonic honing nonlinear system with two degrees of freedom of coupling flutter,and determined the differential expression of the model,and provided a theoretical basis for to further seeking the strategy for repressing and eliminating the flutter.%颤振是功率超声珩磨中极易产生的一种动态强烈自激振动现象,是影响工件加工质量和机床加工效率的重要因素之一.在对功率超声珩磨机理研究的基础上,以单颗磨粒工件系统为研究对象,分别建立了功率超声珩磨系统的两自由度非线性耦合颤振物理模型及数学模型,并确定了其微分方程表达式,为进一步寻求抑制、消除颤振策略提供了理论依据.

  9. Evolution of the Ordos Plateau and environmental effects

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the analysis of temporary-spatial distribution, geomorphic position, contact relationship with underlying strata and grain size of red clay, we studied the formation and environmental background of red clay. During late Miocene-Pliocene, the Ordos Block finished the transformation from the basin to the plateau, which had an obvious environmental effect on the topography, indicated by the formation of highland undergoing wind erosion and lowland receiving red clay deposits. The red clay materials were sourced from dusts carried by wind energy and covered on the initial topography. Unlike Quaternary loess dust covering the overall the Loess Plateau, red clay deposited on the highland would be transported to the lowlands by wind and fluvial process. As a result, there was no continuous "Red Clay Plateau" in the Ordos region and red clay was only preserved in former lowlands. However, red clay was discontinuously distributed through the Loess Plateau and to some extent modified the initial topography. The differential uplift in interior plateau is indicated by the uplift of northern Baiyushan, central Ziwuling and southern Weibeibeishan. The Weibeibeishan Depression formed earlier and became the sedimentary center of red clay resulting in the thicker red clay deposits in Chaona, Lingtai and Xunyi. Since Quaternary the aridity in the northern plateau enhanced and accelerated loess accumulation caused the formation of the Loess Plateau. During the late Pleistocene the rapid uplift led to the enhancement of erosion. Especially after the cut-through of Sanme Lake by the Yellow River, the decline of base level caused the falling of ground water level and at the same time the increase of drainage density resulting in the enhancement of evaporation capacity, which enhanced the aridity tendency of aridity in the Loess Plateau region.

  10. Sandy Desertification Status and its Driving Mechanism in North Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    DONG Yuxiang

    2004-01-01

    As the main body of Qinghai-Tibetan Plateau, North Tibet Plateau is one of three major sandy desertification regions in China and also a representative sandy desertification zone of Qinghai-Tibet Plateau. Accordingly, it is an important region for the study of recent sandy desertification processes and formation mechanism. From such aspects as desertified land types, areas and distributions etc., this paper analyses in detail the sandy desertification status on North Tibet Plateau,and qualitatively and quantitatively deals with the main factors that affect recent sandy desertification processes and the driving mechanism. Research results show that North Tibet Plateau is an important sandy desertification region in China characterized with large desertified land areas, diversified types,high severity, extensive distributions and serious damages. Sandy desertification occurrence and development resulted from combined effects of natural factors, anthropogenic factors, natural processes and man-made processes, of which climatic change is the main driving force.

  11. 试论青藏高原岩浆活动史及其与板块构造的关系%Relation between magmatic evolutionary process and plate tectonics in Qinghai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    季绍新; 余根峰; 邢文臣

    2001-01-01

    In the paper,the Wilson's Vital Cyclicing theory in the ocean was used to explain the magmatism in the south of Qinghai-Tibet plateau,where magmatism underwent rift-type magmatism-ocean-type magmatism-island-type magmatism- col lision-type magmatism-intracontinent collision type magmatism. They reveal the internal relations between the magmatic evolutionary process and plate tectonics .%运用威尔逊的海洋盆地生命旋回理论,阐明青藏 高原南部地区岩浆作用经历了裂谷型岩浆作用—海洋型岩浆作用—岛弧型岩浆作用—碰撞型 岩浆作用—陆内会聚型岩浆作用,从而揭示了青藏高原岩浆活动史与板块构造的内在联系。

  12. High resolution studies of gully erosion, sedimentation processes, and land use changes since the late Pleistocene and future trajectories in the Kazimierz Dolny area (Nałęczów Plateau, SE-Poland)

    Science.gov (United States)

    Dotterweich, M.; Rodzik, J.; Zgłobicki, W.; Schmitt, A.; Schmidtchen, G.; Bork, H. R.

    2012-04-01

    This paper presents the results of 30 years of research on the Doły Podmularskie gully system (catchment 0.35 km2 in size), which is situated in the south-western part of the loess-covered Nałęczów Plateau in SE-Poland. Detailed topographic, stratigraphic and pedologic investigations, and monitoring of a tributary gully (gully area: 0.7 ha, catchment: 2.5 ha), combined with historical, archaeological and palaeoecological records reveal a long and complex history in terms of the temporal and spatial extent and the impact of land use on gully erosion, and the long-term feed-back mechanisms between land use changes and natural processes since the end of the Pleistocene are also expressed. Phases of gully erosion and subsequent filling occurred in the Bronze Age and around the 10th to 11th century. The most severe deepening and expansion of the gully took place in the 17th century. The results also show that field structures and land use intensity had a significant influence on the frequency and magnitude of run-off, soil erosion, piping, and landslide events. The last significant erosion phase started in the mid-19th century with renewed headward retreatment and down-cutting into older gully fills. Today, most of the catchment is either forested or the land is covered in berry shrubs. In the future, the area will continue to produce sediments, because of the steep slopes and because there are still areas of bare soil with a low resistance to erosion, a legacy from past land uses, which will remain a factor affecting soil erosion and sedimentation processes in the future. This study is an example of how important it is to observe and understand slow geomorphologic processes, changes and rare extreme events in the light of land use changes when investigating long-term human-environment interactions.

  13. 基于球面展成原理的小球径内球面珩磨方法%A research on inner spherical honing within small diameter of balls based on spherical generating principle

    Institute of Scientific and Technical Information of China (English)

    张明建

    2014-01-01

    Based on spherical generating principle,this paper conducts a research on grain trajectory in in-ner spherical honing. It develops a grain trajectory model,and proposes a method of high hardness and precision inner spherical honing within small diameter of balls. The actual processing results show that this method can ensure high hardness and high precision honing of inner spherical parts within small diameter of balls.%基于球面的展成原理研究内球面珩磨过程中磨粒在工件上的空间运动轨迹,建立磨粒运动轨迹的数学模型,提出高硬度、高精度小球径内球面的珩磨方法。实际加工结果表明,提出的小球径内球面珩磨方法,可实现高硬度、高精度小球径内球面零件的精密珩磨加工。

  14. The Study of Single Abrasive Grain Dynamics Model During Ultrasonic Honing Chatter%超声珩磨颤振单颗磨粒动力学模型的研究

    Institute of Scientific and Technical Information of China (English)

    刘猛; 祝锡晶; 袁小飞

    2011-01-01

    Chatter is one of the important factors that affect grinding stability and processing quality, dynamic model is usually used to study the stability of ultrasonic honing. In the basis of proposing the basic assumptions on the single Abrasive grain and analysis the mechanism of regenerative chatter, establish three-dimensional and multi-freedom degree of nonlinear dynamic model of ultrasonic honing The dynamic models and equations of single grain in the axial and radial ultrasonic vibration honing was simplified, and provided a basis for to further explore effective methods of suppress and eliminate vibration.%颤振是影响磨削加工稳定性及加工质量的重要因素之一,对于超声珩磨稳定性的研究主要通过动力学模型.在提出对超声珩磨单颗磨粒的基本假设和分析再生型颤振产生机理的基础上,建立了超声珩磨颤振单颗磨粒三维多自由度非线性动力学模型,并简化了轴向和径向超声振动单颗磨粒的动力学模型及其方程,为进一步探求有效的抑振、消振方法提供了依据.

  15. Optically active 6-acetyloxy-2H-pyran-3(6H)-one obtained by lipase catalyzed transesterification and esterification

    NARCIS (Netherlands)

    van den Heuvel, M.; Cuiper, A.D; van der Deen, H.; Kellogg, R.M; Feringa, B.L.

    1997-01-01

    Kinetic resolution of 6-acetyloxy-2H-pyran-3(6H)-one (1) is achieved by immobilized lipase PS on Hyflo Super Cell in organic solvents. Transesterification in hexane/n-butanol yields enantiomerically pure R-(-)-6-acetyloxy-2H-pyran-3(6H)-one, whereas esterification of 6-hydroxy-2H-pyran-3(6H)-one (2)

  16. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    NARCIS (Netherlands)

    Bown, J.; Boye, M.; Laan, P.; Bowie, A.R.; Park, Y.H.; Jeandel, C.; Nelson, D.M.

    2012-01-01

    Processes of cobalt (Co) entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study) in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Pla

  17. INFLUENCE OF WHEEL STRUCTURAL PARAMETERS ON MACHINING ACCURACY OF ULTRA-PRECISION PLANE HONING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new idea for designing wheel patterns is presented so as to solve the problems about machining accuracy ofworkpiece and wear of honing wheel in ultra-precision plane honing. The influence factors on motion principle and pat-tern structures are analyzed and optimization machining parameters are obtained. By calculating effective cutting lengthon the surface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiece contactingwith wheel, the wear coefficient of different kinds of wheels and accuracy coefficient of workpiece machined by corre-sponding wheels are obtained. Furthermore, the simulation results show that the optimal pattern structure of wheel turnsout to have lower wheel wear and higher machining accuracy.

  18. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China

    Science.gov (United States)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing

    2016-10-01

    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  19. Efficient and convenient synthesis of indazol-3(2H)-ones and 2-aminobenzonitriles.

    Science.gov (United States)

    Dou, Guolan; Shi, Daqing

    2009-01-01

    A mild, efficient, one-pot protocol for the synthesis of indazole-3(2H)-ones via cyclization of nitro-aryl substrates through low-valent titanium reagent has been described. The method used Triethylamine (TEA) to control pH. Particularly, 2-aminobenzonitriles were synthesized by one step easily. The mechanistic course of the reaction suggests the involvement of an anion leading to an intramolecular cyclization via N-N bond formation.

  20. Red Clay Sediment in the Central Chinese Loess Plateau and Its Implication for the Uplift of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    SONG Yougui; LI Jijun; FANG Xiaomin; XIA Fei; DONG Hongmei

    2005-01-01

    The widely distributed red clay sediment underlying the Chinese Loess Plateau truly records the Neogene environmental evolution, and its genesis and development are intrinsically related to the uplift processes of the Tibetan Plateau and the evolution of East Asia monsoon system. In this paper, a detailed magnetostratigraphy of a loess-red clay section (107°13′E, 35°02′N) from the central Loess Plateau is reported. The loess-red clay sequence is composed of 175 m Quaternary loess-paleosol sequence and 128 m Neogene red clay sediments. Based on the correlation with the standard geomagnetic polarity time scale, the paleomagnetic results indicate that the age of Chaona red clay sequence extends to 8.1Ma, which is the older red clay deposition in the central Chinese Loess Plateau. The commencement of red clay at ~8.1 Ma may imply that the Ordos planation surface was broken by the movement of the Haiyuan-Liupanshan Faults, which was related to the uplift of the Tibetan Plateau induced by the collision of India Plate and Eurasian Plate. And the western part adjacent to the Tibetan Plateau was uplifted to form the embryo of the Liupan Shan (Mts.) and the eastern part was down-faulted to receive red clay deposition. We link this faulting to an initial uplift of the Tibetan Plateau. The undulating nature of the broken Ordos planation surface may explain the chronological differences and depth discrepancies among various cross-sections of red clay.

  1. Synthesis, cytotoxic activity, and tubulin polymerization inhibitory activity of new pyrrol-2(3H)-ones and pyridazin-3(2H)-ones.

    Science.gov (United States)

    Abbas, Samar Hafez; Abuo-Rahma, Gamal El-Din A A; Abdel-Aziz, Mohamed; Aly, Omar M; Beshr, Eman A; Gamal-Eldeen, Amira M

    2016-06-01

    A series of new pyrrol-2(3H)-ones 4a-f and pyridazin-3(2H)-ones 7a-f were synthesized and characterized using different spectroscopic tools. Some of the tested compounds revealed moderate activity against 60 cell lines. The E form of the pyrrolones 4 showed good cytotoxic activity than both the Z form and the corresponding open amide form. Furthermore, the in vitro cytotoxic activity against HepG2 and MCF-7 cell lines revealed that compounds (E)4b, 6f and 7f showed good cytotoxic activity against HepG2 with IC50 values of 11.47, 7.11 and 14.80μM, respectively. Compounds (E)4b, 6f, 7d and 7f showed a pronounced inhibitory effect against cellular localization of tubulin. Flow cytometric analysis indicated that HepG2 cells treated with (E)4b showed a predominated growth arrest at the S-phase compared to that of G2/M-phase. Molecular modeling study using MOE® program indicated that most of the target compounds showed good binding of β-subunit of tubulin with the binding free energy (dG) values about -10kcal/mole.

  2. Lake overspill and onset of fluvial incision in the Iranian Plateau: Insights from the Mianeh Basin

    Science.gov (United States)

    Heidarzadeh, Ghasem; Ballato, Paolo; Hassanzadeh, Jamshid; Ghassemi, Mohammad R.; Strecker, Manfred R.

    2017-07-01

    Orogenic plateaus represent a prime example of the interplay between surface processes, climate, and tectonics. This kind of an interplay is thought to be responsible for the formation, preservation, and, ultimately, the destruction of a typical elevated, low-internal relief plateau landscape. Here, we document the timing of intermontane basin filling associated with the formation of a low-relief plateau morphology, followed by basin opening and plateau-flank incision in the northwestern Iranian Plateau of the Arabia-Eurasia collision zone. Our new U-Pb zircon ages from intercalated volcanic ashes in exposed plateau basin-fill sediments from the most external plateau basin (Mianeh Basin) document that the basin was internally drained at least between ∼7 and 4 Ma, and that from ∼5 to 4 Ma it was characterized by an ∼2-km-high and ∼0.5-km-deep lake (Mianeh paleolake), most likely as a result of wetter climatic conditions. At the same time, the eastern margin of the Mianeh Basin (and, therefore, of the Iranian Plateau) experienced limited tectonic activity, as documented by onlapping sediments and smoothed topography. The combination of high lake level and subdued topography at the plateau margin led to lake overspill, which resulted in the cutting of an ∼1-km-deep bedrock gorge (Amardos) by the Qezel-Owzan River (QOR) beginning at ∼4 Ma. This was associated with the incision of the plateau landscape and the establishment of fluvial connectivity with the Caspian Sea. Overall, our study emphasizes the interplay between surface and tectonic processes in forming, maintaining, and destroying orogenic plateau morphology, the transitional nature of orogenic plateau landscapes on timescales of 106 yr, and, finally, the role played by overspilling in integrating endorheic basins.

  3. 黄土高原丘陵沟壑区包气带土壤水运移过程%Migration process of soil water in the unsaturated zone of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    杨永刚; 李国琴; 焦文涛; 黄磊

    2016-01-01

    包气带土壤水运移过程是黄土高原生态修复中亟需回答的关键科学问题。环境同位素方法可获取其他方法难以获取的水文过程信息。通过对黄土高原丘陵沟壑区羊圈沟小流域降水、包气带0~150 cm土壤水和绣线菊( Spi⁃raea salicifolia)木质部水等样品的同位素δD和δ18 O进行测定。结果表明:羊圈沟小流域降水同位素组成受蒸发作用影响较大,呈现明显分馏效应。包气带土壤水、降水与木质部水同位素组成存在明显月份变化特征。降水是土壤水的主要补给来源,灌丛的水分利用来源主要为降水和土壤水,符合降水⁃土壤水⁃植被水的运移特征。灌丛木质部水和20~40 cm土壤水δD和δ18 O最为接近,20~40 cm土壤水是灌丛水分利用的主要来源。研究揭示了包气带土壤水运移过程及植物水分利用来源,为土壤水运移过程、模型结构与参数识别等提供科学依据。%The mechanism of soil water migration in the reconstruction and restoration of the Loess Plateau is a key scientific problem that must be solved. Isotopic tracers can provide valuable information associated with complex hydro⁃logical problems and are difficult to obtain by other methods. This study investigated soil water migration in the unsatu⁃rated zone in the hilly and gully region of the Loess Plateau. Samples were collected from the 0—150 cm unsaturated zone, including precipitation, soil water content, plant xylems, and plant roots, and were analysed. The results showed that the isotopic composition of precipitation in the Yangjuangou River basin was affected by evaporation, as indicated by isotopic fractionation phenomena. The δD and δ18 O isotopic profiles of the soil water exhibited monthly variations. The soil water was recharged by precipitation. The soil water and precipitation were taken up by shrubland. Water migration exhibited a transformation pathway from

  4. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

    Directory of Open Access Journals (Sweden)

    Minal Desai

    2012-03-01

    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  5. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

    Directory of Open Access Journals (Sweden)

    Minal Desai

    2012-03-01

    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  6. The Pajarito Plateau: a bibliography

    Science.gov (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.

    1993-01-01

    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  7. Monuments of the Giza Plateau

    Science.gov (United States)

    Ruggles, Clive L. N.

    The colossal pyramids of the pharaohs Khufu (Cheops), Khafre (Chephren), and Menkaure (Mycerinus) have attracted a huge amount of astronomical interest over the years, both scholarly and popular. Less attention is usually given to the broader context of structures on the Giza Plateau. One of the most notorious ideas connecting the Giza Plateau with astronomy is that the three large pyramids are laid out on the ground so as to reflect the appearance of the three stars of Orion's Belt in the sky. This idea is unsupportable for several reasons but has succeeded in generating huge public interest. Of much greater serious interest is the fact that the three main pyramids were oriented cardinally to extraordinary precision, which raises the questions of why this was important and how it was achieved. Another idea that has attracted serious attention but also some confusion is that the orientations of some narrow shafts within Khufu's pyramid might have been deliberately aligned upon particular stars. The overall layout of monuments on the plateau may certainly have been designed so as to emphasize certain solar phenomena, for symbolic and ideological reasons relating to a dominant sun cult. It is also possible that it formed part of a wider cosmological "master plan" extending to other pyramids and temples up to 20 km distant.

  8. A study of the parameterization of land-surface processes over the natural vegetation surface of Loess Plateau%黄土高原自然植被下垫面陆面过程参数研究

    Institute of Scientific and Technical Information of China (English)

    李宏宇; 张强; 史晋森; 赵建华; 王胜

    2012-01-01

    Based on the data observed at the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) , the physical parameters related to land-surface processes over the natural vegetation surface of Loess Plateau are calculated. The paper studied averaged diurnal variations and the frequency distributions of the bulk transfer coefficients in the different seasons, and analyzed the trend of the surface roughness as well as effects of precipitation on the roughness. Monthly averages of the roughness in a normal year of precipitation have more changes compared with those in a dryer year since precipitation increasing tends to increase the roughness. The roughness in a normal year is 9 ×10-3m, while the roughness in a dryer year decreases to 6×l0-3m. The rainfall raises the roughness by increasing the vegetation cover and height. Relationships a-mong the bulk transfer coefficients and the two factors including surface roughness and the Richardson number are discussed. The role of dynamical transfer in land-atmosphere energy exchange over the Loess Plateau is dominant. Additionally, the neutral bulk transfer coefficient for momentum is close to that over the movable dune at Naiman in Inner Mongolia and the neutral bulk transfer coefficient for sensible heat is close to that over Gobi. We also analyzed effects of solar elevation angle and soil moisture on surface albedo and preliminarily a multiple factorial parameterization formula of surface albedo is suggested. Generally, the albedo over the Loess Plateau is smaller than that over the desert of Dunhuang and larger than that over pine forests in Changbai Mountain. The various vegetation covers and soil types in the three regions lead to differences of albedo. By testing the simulation results of the albedo formula, it is found that the albedo with low solar elevation angles is sensitive to the other factors except soil moisture and solar elevation angle, while soil moisture and solar elevation angle affect

  9. Combined experimental and computational study on the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Margarida S., E-mail: msmirand@fc.up.p [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Centro de Geologia da Universidade do Porto, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Matos, M. Agostinha R., E-mail: marmatos@fc.up.p [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Morais, Victor M.F., E-mail: vmmorais@icbas.up.p [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal); Instituto de Ciencias Biomedicas Abel Salazar, ICBAS, Universidade do Porto, P-4099-003 Porto (Portugal); Liebman, Joel F., E-mail: jliebman@umbc.ed [Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States)

    2011-05-15

    Research highlights: The standard molar enthalpies of formation and sublimation of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one were determined. Computational calculations predict that keto tautomers are more stable than the enol ones. G3(MP2)//B3LYP calculations allowed estimation of the standard enthalpies of formation. The aromaticity of both compounds was evaluated by analysis of NICS values. - Abstract: The present work reports an experimental and computational study of the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one. The standard (p{sup o} = 0.1 MPa) massic energy of combustion, at T = 298.15 K, of each compound was measured by rotating bomb combustion calorimetry, in oxygen that allowed the calculation of the respective standard molar enthalpy of formation, in the condensed phase, at T = 298.15 K. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by high-temperature Calvet microcalorimetry. From the combination of data obtained by both techniques we have calculated the standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K. In addition, computational calculations were carried using the density functional theory with the B3LYP functional and the 6-31G* basis set and some correlations between structure and energetics were obtained for the keto and enol forms of both compounds. Using the G3(MP2)//B3LYP composite method and various appropriate reactions, the standard molar enthalpies of formation of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one, at T = 298.15 K, were computationally derived and compared with the experimental data. The aromaticity of 1,2-benzisothiazol-3(2H)-one, 1,4-benzothiazin-3(2H, 4H)-one and that of some related species was evaluated by analysis of nucleus independent chemical shifts (NICS).

  10. Synthesis and biological activity of novel series of 1,3-benzoxazol-2(3H)-one derivatives.

    Science.gov (United States)

    Krawiecka, Mariola; Kuran, Bozena; Kossakowski, Jerzy; Kierzkowska, Marta; Młynarczyk, Grazyna; Cieślak, Marcin; Kaźmierczak-Barańska, Julia; Królewska, Karolina; Dobrowolski, Michał A

    2013-01-01

    In the search for novel biological agents, a series of new derivatives N-substituted 1,3-benzoxazol-2(3H)-one, 5-chloro-1,3-benzoxazol-2(3H)-one, 6-bromo-1,3-benzoxazol-2(3H)-one were prepared. All of the compounds were characterized by 1H NMR, 13C NMR and ESI MS spectra. Moreover, for compound 1 an Xray structure was determined. All derivatives were tested for antimicrobial activity against a selection of Gram-positive, Gram-negative bacteria and yeasts. The selected compounds (2-8, 10) were tested for their cytotoxic properties in K562, HeLa and normal cells.

  11. Biodiversity and conservation in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Tibetan Plateau (Qinghai-Xizang Plateau) is a unique biogeographic region in the world, where various landscapes, altitudinal belts, alpine ecosystems, and endangered and endemic species have been developed. A total of 26 altitudinal belts, 28 spectra of altitudinal belts, 12,000 species of vascular plant, 5,000 species of epiphytes, 210 species of mammals, and 532 species of birds have been recorded. The plateau is also one of the centers of species formation and differentiation in the world. To protect the biodiversity of the plateau, about 80 nature reserves have been designated, of which 45 are national or provincial, covering about 22% of the plateau area. Most of the nature reserves are distributed in the southeastern plateau. Recently, the Chinese government has initiated the "Natural Forests Protection Project of China,' mainly in the upper reaches of the Yangtze and Yellow rivers. "No logging" policies have been made and implemented for these areas.

  12. A study of the bone healing kinetics of plateau versus screw root design titanium dental implants.

    LENUS (Irish Health Repository)

    Leonard, Gary

    2009-03-01

    This study was designed to compare the bone healing process around plateau root from (PRF) and screw root from (SRF) titanium dental implants over the immediate 12 week healing period post implant placement.

  13. Synthesis of Novel 2-(Substituted aminoalkylthiopyrimidin-4(3H-ones as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Mohamed I. Attia

    2013-12-01

    Full Text Available 5-Alkyl-6-(substituted benzyl-2-thiouracils 3a,c were reacted with (2-chloroethyl diethylamine hydrochloride to afford the corresponding 2-(2-diethylaminoethylthiopyrimidin- 4(3H-ones 4a,b. Reaction of 3a–c with N-(2-chloroethylpyrrolidine hydrochloride and/or N-(2-chloroethylpiperidine hydrochloride gave the corresponding 2-[2-(pyrrolidin-1-ylethyl]-thiopyrimidin-4(3H-ones 5a–c and 2-[2-(piperidin-1-ylethyl]thiopyrimidin-4(3H-ones 6a,b, respectively. Treatment of 3a–d with N-(2-chloroethylmorpholine hydrochloride under the same reaction conditions formed the corresponding 2-[2-(morpholin-4-ylethyl]thiopyrimidines 6c–f. On the other hand, 3a,b were reacted with N-(2-bromoethylphthalimide and/or N-(3-bromopropylphthalimide to furnish the corresponding 2-[2-(N-phthalimidoethyl]-pyrimidines 7a,b and 2-[3-(N-phthalimido-propyl]pyrimidines 7c,d, respectively. Compounds 3a–d, 4a,b, 5a–c, 6a–f and 7a–d were screened against Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Bacillus subtilis NRRL 4219 and Bacillus cereus, yeast-like pathogenic fungus (Candida albicans ATCC 10231 and a fungus (Aspergillusniger NRRL 599. The best antibacterial activity was displayed by compounds 3a, 3b, 4a, 5a, 5b, 6d, 6f, 7b and 7d, whereas compounds 4b, 5b, 5c, 6a, 6b and 6f exhibited the best antifungal activity.

  14. 3-(4-Bromophenyl-4-(4-hydroxyanilinofuran-2(5H-one

    Directory of Open Access Journals (Sweden)

    Wanxi Peng

    2011-09-01

    Full Text Available In the title compound, C16H12BrNO3, the butyrolactone core adopts the furan-2(5H-one structure and forms dihedral angles of 44.80 (17 and 65.73 (18° with the bromobenzene and phenol rings, respectively. In the crystal, N—H...O and O—H...O hydrogen bonds link the molecules, generating R43(26 loops The edge-fused rings extend to form a chain running along the b-axis direction and C—H...π contacts help to consolidate the packing.

  15. 1-(4-Methylbenzyl-1H-benzimidazol-2(3H-one

    Directory of Open Access Journals (Sweden)

    Lahcen El Ammari

    2013-01-01

    Full Text Available In the title compound, C15H14N2O, the fused five- and six-membered ring system is essentially planar, the maximum deviation from the mean plane being 0.009 (1 Å. The benzimidazol-2(3H-one residue is nearly perpendicular to the benzyl ring, forming a dihedral angle of 77.41 (6°. In the crystal, inversion dimers are formed by pairs of N—H...O hydrogen bonds; these dimers are linked by weak C—H...O interactions into a two-dimensional array in the (102 plane.

  16. The Experimental and Theoretical Research of "Local Resonance" in Ultrasonic Honing System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In 1982, Professor Fang Guoliang found the "Non full resonance" phenomenon in a tool system while he use the thin-long tool ultrasonically machining deep-small hole. He called it as "local resonance". Also this "Non full resonance" phenomenon was discovered in the ultrasonic drilling and the ultrasonic honing system later. To its mechanism, professor Fang thought that the coupling of long-thin tool bar and driving system is weak, so the tool bar can vibrate independently, but the quantitative relation betwe...

  17. Synthesis and antimicrobial activities of new oxime carbamates of 3-aryl-2-thioquinazolin-4(3H)-one

    Indian Academy of Sciences (India)

    Suresh S Patil; Swati D Jadhav; M B Deshmukh

    2012-09-01

    S-alkylation of 3-aryl-2-thioquinazolin-4(3H)-one (1) with chloroacetone gave 2-(propanonyl thio)-3-arylquinazol-4(3H)ones (2). Further, the treatment of compound (2) with hydroxylamine hydrochloride gave the corresponding oximes (3) which on reaction with phenyl isocyanate in THF yielded corresponding oxime carbamates 4. The synthesized compounds have been confirmed using IR and 1H NMR, mass spectral data together with elemental analysis. All newly synthesized compounds have been tested for their antibacterial and antifungal activities.

  18. Excessive afforestation and soil drying on China's Loess Plateau

    Science.gov (United States)

    Zhang, Shulei; Yang, Dawen

    2017-04-01

    Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess Plateau following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess Plateau. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess Plateau, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess Plateau should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.

  19. Improving Retention and Fit by Honing an Honors Admissions Model

    Science.gov (United States)

    Smith, Patricia Joanne; Zagurski, John Thomas Vitus

    2013-01-01

    Since SAT and ACT tests have been long-suspected and then shown to contain class and race biases while not accurately predicting retention, the Schedler Honors College at the University of Central Arkansas (UCA) shifted to a holistic, multi-criterion selection process, de-emphasizing standardized tests, and then analyzed the outcomes. This essay…

  20. 高硅铝合金无缸套发动机缸体缸孔珩磨加工数控机床关键技术研究%Research on Key Technologies of High-silicon Aluminum Alloy No-cylinder-liner Engine Block Cylinder Bore Honing CNC Machine Tool

    Institute of Scientific and Technical Information of China (English)

    余阿东; 王平俊; 李翔龙

    2016-01-01

    Based on high⁃silicon aluminum alloy no⁃cylinder⁃liner engine block bore materials grinding characteristics, a dual⁃spindle CNC honing machine tool was developed. In the machine tool, two⁃position two⁃spindle honing layout was used, it consisted of the following modules:spindle box, column, column glide, workpiece clamping table and so on. Spindle honing dual feed mechanism and honing oilstone double feed body were adopted. A closed loop control system based on motion control card was used. The system hardware platform was IPC and general industrial motion control card, based on the pneumatic differential pressure measuring honing online system, processing volume closed⁃loop control was achieved. The software platform was Windows system, VC++ development tool was used to program specialized processing procedures for the honing process.%基于高硅铝合金无缸套发动机缸体缸孔材料的磨削特点,开发了一种数控双主轴珩磨机床。该机床采用二工位双主轴的珩磨加工布局,由以下模块组成:主轴箱、立柱、立柱下滑台、工件装夹工作台等;采用主轴珩磨双进给机构及珩磨头油石双涨机构;采用基于运动控制卡的全闭环控制系统,系统硬件平台采用工控机和通用工业运动控制卡,运用基于差压式珩磨在线气动测量系统,实现加工量的闭环控制;软件平台采用Windows系统,采用VC++开发工具编制珩磨工艺加工程序。

  1. 基于空化效应的功率超声珩磨再生型颤振研究%Research on Regenerative Chatter of Power Ultrasonic Honing Based on Cavitation Effects

    Institute of Scientific and Technical Information of China (English)

    许鑫; 刘国东

    2016-01-01

    Power ultrasonic honing has been proved to be a complex vibration system, grindering chatter may be generated during power machining process, and many different influence factors can cause the chatter such as physical grinding process, mechanical vi-bration, high frequency vibration and ultrasonic transmission system.The dynamic model of chatter of power ultrasonic honing was es-tablished.The influence of acoustic pressure radiated by collapsing cavitation on the regenerative chatter was researched mainly.The re-sults show that the main cause of the regenerative chatter of power ultrasonic honing is the thickness of the grinding;the acoustic pres-sure radiated by collapsing cavitation can increase the frequency of chatter of the system, but no obvious effects on the change trends of time domain and amplitude of the system.%功率超声珩磨加工过程中的颤振影响因素很多,不仅包含物理磨削过程和机械振动环节,还包含了高频振动和超声波传动系统,是一个非常复杂的复合振动系统.通过建立珩磨颤振动力学模型,重点研究珩磨中空化泡溃灭产生辐射声压对再生型颤振的影响,结果表明:决定功率超声珩磨再生型颤振的主要原因为磨削厚度;空化泡溃灭产生的辐射声压会加剧系统颤振的频率,但对系统颤振的时域图变化趋势和振幅的大小基本没有影响.

  2. Machine integrated optical measurement of honed surfaces in presence of cooling lubricant

    Science.gov (United States)

    Schmitt, R.; König, N.; Zheng, H.

    2011-08-01

    The measurement of honed surfaces is one of the most important tasks in tribology. Although many established techniques exist for texture characterization, such as SEM, tactile stylus or white-light interferometry, none of them is suited for a machine integrated measurement. Harsh conditions such as the presence of cooling lubricant or vibrations prohibit the use of commercial sensors inside a honing machine. Instead, machined engine blocks need time-consuming cleaning and preparation while taken out of the production line for inspection. A full inspection of all produced parts is hardly possible this way. Within this paper, an approach for a machine-integrated measurement is presented, which makes use of optical sensors for texture profiling. The cooling lubricant here serves as immersion medium. The results of test measurements with a chromatic-confocal sensor and a fiber-optical low-coherence interferometer show the potential of both measuring principles for our approach. Cooling lubricant temperature and flow, scanning speed and measurement frequency have been varied in the tests. The sensor with best performance will later be chosen for machine integration.

  3. Machine integrated optical measurement of honed surfaces in presence of cooling lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R; Koenig, N; Zheng, H, E-mail: n.koenig@wzl.rwth-aachen.de [Laboratory for Machine Tools and Production Engineering of RWTH Aachen University, Steinbachstr. 19, 52074 Aachen (Germany)

    2011-08-19

    The measurement of honed surfaces is one of the most important tasks in tribology. Although many established techniques exist for texture characterization, such as SEM, tactile stylus or white-light interferometry, none of them is suited for a machine integrated measurement. Harsh conditions such as the presence of cooling lubricant or vibrations prohibit the use of commercial sensors inside a honing machine. Instead, machined engine blocks need time-consuming cleaning and preparation while taken out of the production line for inspection. A full inspection of all produced parts is hardly possible this way. Within this paper, an approach for a machine-integrated measurement is presented, which makes use of optical sensors for texture profiling. The cooling lubricant here serves as immersion medium. The results of test measurements with a chromatic-confocal sensor and a fiber-optical low-coherence interferometer show the potential of both measuring principles for our approach. Cooling lubricant temperature and flow, scanning speed and measurement frequency have been varied in the tests. The sensor with best performance will later be chosen for machine integration.

  4. Synthesis, antibacterial and antifungal activity of pyrazolyl-quinazolin-4(3H-one derivatives

    Directory of Open Access Journals (Sweden)

    Navin B. Patel

    2011-03-01

    Full Text Available A series of pyrazolyl-quinazolin-4(3H-ones 6a-m have been synthesized from 2-[2-(phenylaminophenyl]acetic acid by using efficient methods. An acid chloride of 2-[2-(phenylaminophenyl]acetic acid on cyclization reaction with 5-iodo anthranilic acid yielded benzoxazinone 2, which on condensation reaction with hydrazine hydrate afforded quinazolin-4(3H-one 3. Acetylation of compound 3 and then condensation with aromatic aldehydes led to the formation of chalcones 5a-m which on subjected to reaction with phenyl hydrazine yielded the disired compounds 6a-m. All the synthesized componds have been characterized by elemental analyses, IR and NMR spectra data. The title compounds have been screened against bacterial as well as fungal microorganisms. The potency of these compounds was calculated and compared with standard drugs i.e. Penicillin-G and Fluconazole. Some of the compounds showed very good antimicrobial activity.

  5. Degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau, Southwest China%滇西北高原纳帕海湖滨湿地退化特征、规律与过程

    Institute of Scientific and Technical Information of China (English)

    尚文; 杨永兴

    2012-01-01

    采用双向指示种分析(TWINSPAN)和典范对应分析(CCA)方法,研究了滇西北高原纳帕海湖滨湿地退化特征、规律与过程.结果表明:纳帕海湖滨湿地植物群落可以划分为4个群丛,群落演替规律为水生植物群落→沼泽植物群落→沼泽化草甸植物群落→草甸植物群落.随植物群落演替,群落盖度、密度、多样性指数、物种丰富度和地上生物量均增大,群落高度减小;植物水分生态型演替规律为水生植物→沼生植物→湿生植物→中生植物.随群落演替,湿地水体矿化度、硬度和碱度均降低,氨氮和总磷含量升高,总氮和硝态氮含量变化不明显;土壤pH、有机质和全氮含量逐渐降低,全磷和全钾含量逐渐升高,速效氮和速效磷含量先增大后减小.CCA分析表明,群落结构和物种组成主要受水分梯度影响,土壤pH、全磷和湿地水的总氮、氨氮对湿地植物物种分布和群落演替影响显著.%Two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA) were employed to analyze the degradation characteristics, patterns, and processes of lakeside wetland in Napahai of northwest Yunnan Plateau. The plant communities in the lakeside wetland could be classified into four associations, according to the TWINSPAN results. The succession patterns of the plant community were represented by aquatic plant community→swamp plant community→swamp meadow plant community→meadow plant community. During die processes of succession, the plant community coverage, density, Shannon diversity index, species richness, and plant aboveground biomass increased, whereas the community height decreased. The succession of the plant hydro-ecotypes followed the sequence of aquatic→helophyte→hygrophyte→ meso-phyte. With the succession of the plant community, the wetland water quality indices salinity, alkalinity, and hardness decreased but ammonium nitrogen and total phosphorus

  6. Argentina's YPF hones in on privatization

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-30

    This paper reports on Argentina's push to privatize and attract more foreign investment to its petroleum sector which continues to gather momentum. The Argentine government plans by year end 1992 to sell unprofitable assets of Yacimientos Petroliferos Fiscales, then sell as much as 50% of the state oil company through an international stock offering. If privatization proceeds as expected, YPF Pres. Jose Estenssoro the, the company's stock will be offered to private investors early in 1993. The company was founded in 1922. By March 1992, Argentina also will begin selling all assets of state owned Gas del Estado (GDE) through an international bidding process expected to take about 18 months.

  7. Prehistoric human settling on the Tibetan Plateau

    Science.gov (United States)

    Chen, Fahu; Zhang, Dongju; Dong, Guanghui

    2017-04-01

    When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By studying hand- and footprints in Chusang, Meyer et al. (2016) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene without the help of agriculture. However, we think the limited hand- and footprints evidence found in Chusang could indicate no more than prehistoric hunter-gatherers presence on the remote central Tibetan Plateau in the early Holocene. In addition, by reviewing all the published archaeological data, we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in Tibetan Plateau, even above 3000 masl, during mid- and late Holocene. References: Chen et al., 2015. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347: 248-250. Meyer et al., 2016

  8. Acylated 2-(N-arylaminomethylenebenzo[b]thiophene-3(2H-Ones: Molecular Switches with Varying Migrants and Substituents

    Directory of Open Access Journals (Sweden)

    Alexander D. Dubonosov

    2009-01-01

    Full Text Available Synthesis and properties of photochromic acylated 2-(N-arylaminomethylenebenzo[b]thiophene-3(2H-ones are described. Their structure largely depends on the nature of acyl migrant and in a less degree on N-aryl substituent.

  9. Synthesis of 3-Bromotetronamides via Amination of 3,4-Dibromofuran-2(5H)-one

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Silvio; Oliveira, Caio C., E-mail: silviodc@ufba.b [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Instituto Nacional de Ciencia e Tecnologia (INCT) em Energia, Salvador, BA (Brazil); Sabino, Jose R. [Universidade Federal de Goias (IF/UFG), Goiania (Brazil). Inst. de Fisica

    2011-07-01

    This work describes the direct synthesis of 3-bromotetronamides in good yields through the reaction of 3,4-dibromofuran-2(5H)-one, obtained from furfural, with primary and secondary amines. Aromatic amines were more tolerated than aliphatic and heteroaromatic ones. The X-ray structures of five derivatives are described. (author)

  10. Numerical study of Peakons and k-Solitons of the Camassa-Holm and Holm-Hone equations

    Science.gov (United States)

    Popov, S. P.

    2011-07-01

    The spectral Fourier and Runge-Kutta methods are used to study the Camassa-Holm and Holm-Hone equations numerically. Numerical results for problems with initial data leading to the generation and interaction of peakons and k-solitons are discussed.

  11. Synthesis of a Biologically Active Oxazol-5-(4H)-One via an Erlenmeyer-Plo¨chl Reaction

    Science.gov (United States)

    Rodrigues, Catarina A. B.; Martinho, Jose´ M. G.; Afonso, Carlos A. M.

    2015-01-01

    The synthesis of (Z)-4-(4-nitrobenzylidene)-2- phenyloxazol-5(4"H")-one, which is a potent immunomodulator and tyrosinase inhibitor, is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. This compound is produced via an Erlenmeyer-Plo¨chl reaction in the absence of any additional solvents…

  12. Synthesis of a Biologically Active Oxazol-5-(4H)-One via an Erlenmeyer-Plo¨chl Reaction

    Science.gov (United States)

    Rodrigues, Catarina A. B.; Martinho, Jose´ M. G.; Afonso, Carlos A. M.

    2015-01-01

    The synthesis of (Z)-4-(4-nitrobenzylidene)-2- phenyloxazol-5(4"H")-one, which is a potent immunomodulator and tyrosinase inhibitor, is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. This compound is produced via an Erlenmeyer-Plo¨chl reaction in the absence of any additional solvents…

  13. Spatio-temporal dynamics of evapotranspiration on the Tibetan Plateau from 2000 to 2010

    Science.gov (United States)

    Song, Lulu; Zhuang, Qianlai; Yin, Yunhe; Zhu, Xudong; Wu, Shaohong

    2017-01-01

    Evapotranspiration (ET) is a key process of the climate system because it links water, energy and carbon cycles. In this study we modified a Penman-Monteith based algorithm to estimate ET on the Tibetan Plateau at a 1 km spatial resolution for the period 2000-2010 using meteorological and satellite remote sensing data. The results showed that the average annual ET on the Tibetan Plateau was 350.3 mm year-1 and decreased from the southeast toward the northwest. The highest ET value was found in open water bodies (680.9 mm year-1) and the lowest ET value was found in open shrubland (254.0 mm year-1). Overall, the inter-annual ET decreased from 2000 to 2010 and there was significant negative ET trend over 42% of the region, primarily in the northwest of the Tibetan Plateau. Relative humidity was the dominant factor in controlling long-term variations of ET in the arid northwest plateau. But under moist conditions, leaf area index or temperature drove ET. In addition, P-ET on the Tibetan Plateau significantly increased and about 37% of the region showed strong positive P-ET trend primarily in the central of the Tibetan Plateau. The positive P-ET trend in four seasons suggested that the Tibetan Plateau might have become wetter during the past decade.

  14. Honing the in silico toolkit for detecting protein disorder.

    Science.gov (United States)

    Esnouf, Robert M; Hamer, R; Sussman, J L; Silman, I; Trudgian, D; Yang, Z-R; Prilusky, Jaime

    2006-10-01

    Not all proteins form well defined three-dimensional structures in their native states. Some amino-acid sequences appear to strongly favour the disordered state, whereas some can apparently transition between disordered and ordered states under the influence of changes in the biological environment, thereby playing an important role in processes such as signalling. Although important biologically, for the structural biologist disordered regions of proteins can be disastrous even preventing successful structure determination. The accurate prediction of disorder is therefore important, not least for directing the design of expression constructs so as to maximize the chances of successful structure determination. Such design criteria have become integral to the construct-design strategies of laboratories within the Structural Proteomics In Europe (SPINE) consortium. This paper assesses the current state of the art in disorder prediction in terms of prediction reliability and considers how best to use these methods to guide construct design. Finally, it presents a brief discussion as to how methods of prediction might be improved in the future.

  15. Synthesis and Antibacterial Activity of 3-(Substituted)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one

    OpenAIRE

    Ramgopal Appani; Baburao Bhukya; Kiran Gangarapu

    2016-01-01

    A series of novel 3-(substituted)-2-(substituted quinazolinylamino)quinazolin-4(3H)-ones were synthesized by the reaction of 3-(substituted)-2-hydrazino-quinazoline-4(3H)-ones with 2-phenyl-3,1-benzoxazin-4-one. The starting materials 3-(substituted)-2-hydrazino-quinazolin-4(3H)-ones were synthesized from various primary amines by a multistep synthesis. All the title compounds were tested for their antibacterial activity using ciprofloxacin as reference standard. Compounds 3-(4-fluorophenyl)-...

  16. Research on the electromagnetic field and temperature field of magnetic honing system%磁性珩磨系统电磁场和温度场的研究

    Institute of Scientific and Technical Information of China (English)

    杨慧; 杨平; 李雪红; 姚新改

    2014-01-01

    Magnetic honing technology utilizes electromagnetic interaction to rotate and axially translate a rotor abrasive on the in -ner surface of workpiece ,so as to effectively solve the practical issue that the inner surface of the long stainless steel pipes are hardly polished since they are too long and not suitably rotated at high speed .On the basis of electromechanics ,magnetic honing system is optimized and designed and the electromagnetic field and temperature field ,which are the main factors influencing work-piece processing ,are analyzed based on Ansoft software and ANSYS Workbench software and using the heat transfer theory .The result of the analysis provided reliable theoretical basis for the design of magnetic honing system .%磁性珩磨技术是利用电磁作用驱动磁性磨具在工件内腔运动,从而有效地解决由于结构本身的特殊性而不宜做高速旋转运动的长不锈钢管内表面加工难的实际问题。磁性珩磨系统的电磁场和温度场是影响加工的主要因素,以电机学知识为基础,运用传热学理论,借助Ansoft软件和ANSYS Workbench 软件对磁性珩磨系统进行优化设计,并对其进行电磁场和温度场分析,为磁性珩磨系统的设计提供理论依据。

  17. Numerical simulation of GPS observed clockwise rotation around the eastern Himalayan syntax in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    CAO dianLing; SHI YaoLin; ZHANG Huai; WANG Hui

    2009-01-01

    From Global Position System (GPS) measurements,there is a clockwise rotation around the eastern Himalayan syntax in the Tibetan Plateau.This phenomenon is difficult to be interpreted by simple two-dimensional modeling from a geodynamic point of view.Because of the extremely thick crust and the lower crust with relatively high temperature in the Tibetan Plateau,the lithospheric rheology in Tibet and surrounding areas present a complex structure,in general,the tectonic structure of the Tibetan Plateau consists of brittle upper crust,ductile lower crust,high viscosity lithospheric upper mantle,and low viscosity asthenosphere,the same as the case in many other continental regions.However,the lower crust in the Tibetan Plateau is much more ductile with a lower viscosity than those of its sur-roundings at the same depth,and the effective viscosity is low along the collision fault zone.In this study,we construct a three-dimensional Maxwell visco-elastic model in spherical coordinate system,and simulate the deformation process of the Tibetan Plateau driven by a continuous push from the Indian plate.The results show that the existence of the soft lower crust under the plateau makes the entire plateau uplift as a whole,and the Himalayas and the eastern Himalayan syntax uplift faster.Since the lower crust of surrounding blocks is harder except in the southeastern corner where the high-temperature material is much softer and forms an exit channel for material transfer,after the whole plateau reaches a certain height,the lower crustal and upper mantle material begins to move eastward or southeastward and drag the upper crust to behave same way.Thus,from the macroscopic point of view,a relative rigid motion of the plateau with a clockwise rotation around the eastern Himalayan syntax is developed.

  18. Project management of business process

    OpenAIRE

    Jovanović, Slaviša

    2011-01-01

    This thesis presents one of the hottest areas in today's software industry, business process management (. Business Process Management has become an important tool for companies to hone their capabilities and business processes to adjust rapid and sudden changes in the marketplace and achieve the set of plans. Thesis is divided into two parts. The first section provides an overview of the scope of business process management through the project approach, historically defined its...

  19. Compressive Tectonics around Tibetan Plateau Edges

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhixin; Xu Jiren

    2009-01-01

    Various earthquake fault types, mechanism solutions, stress field, and other geophysical data were analyzed for study on the crust movement in the Tibetan plateau and its tectonic implications. The results show that numbers of thrust fault and strike-slip fault type earthquakes with strong compressive stress near NNE-SSW direction occurred in the edges around the plateau except the eastern boundary. Some normal faulting type earthquakes concentrate in the Central Tibetan plateau. The strikes of fault planes of thrust and strike-slip faulting earthquakes are almost in the E-W direction based on the analyses of the Wulff stereonet diagrams of fault plane solutions. This implies that the dislocation slip vectors of the thrust and strike-slip faulting type events have quite great components in the N-S direction. The compression motion mainly probably plays the tectonic active regime around the plateau edges. The compressive stress in N-S or NE-SW directions predominates earthquake occurrence in the thrust and strike-slip faulting event region around the plateau. The compressive motion around the Tibetan plateau edge is attributable to the northward motion of the Indian subcontinent plate. The northward motion of the Tibetan plateau shortened in the N-S direction encounters probably strong obstructions at the western and northern margins.

  20. Analysis of Mechanism of Tibetan Plateau Vortex Frequency Differences between Strong and Weak MJO Periods

    Science.gov (United States)

    Li, Guoping; Zhao, Fuhu

    2017-04-01

    There are many unique weather systems over the Tibetan Plateau (TP). Among them, the TP vortex (TPV for short) is representative of the low air pressure weather systems. The generation, development and eastward propagation of the TPV is usually accompanied by precipitation, strong winds, thunderstorms and other weather processes, resulting in a series of extreme weather events over the TP and the Sichuan-Chongqing basin where is the downstream of the plateau. Some TPVs, which move from the plateau to the east and develop strongly, even affect a wide range of China's eastern region. NCEP/DOE reanalysis data, OLR data from NOAA, the Australian Meteorological Bureau Real-time Multivariate MJO index, and Tibetan Plateau vortex (TPV) statistical data from the Institute of Plateau Meteorology, are used to discuss the modulation of the TPV by the MJO. Wavelet analysis and composite analysis are the methods used. The results show that: (1) The MJO plays an important role in modulating the TPV, for the number of TPVs generated in strong MJO periods is three times more than in weak periods. (2) During strong (weak) MJO periods, the Tibetan Plateau is in control of a low-frequency, low-pressure cyclone (high-pressure anticyclone) system, and thus the atmospheric circulation conditions over the plateau are conducive (not conducive) to the generation of TPVs. (3) During strong (weak) MJO periods, southerly (northerly) winds prevail in the east of the plateau, but northerly (southerly) winds in the west. Over the northern part of the plateau, easterly (westerly) flow is predominant, while westerly (easterly) flow prevails over the south, thus conducive (not conducive) to the formation of cyclonic circulation (i.e., TPVs) at low altitude over the plateau. (4) In strong MJO periods, water vapor is relatively less abundant over most of the plateau, which is not conducive to the generation of TPVs; however, moisture transported by the south branch trough and the low-frequency, high

  1. Constructions of new plateaued functions from known ones

    Institute of Scientific and Technical Information of China (English)

    Zhang Weiguo; Ding Yong; Zhang Ning; Xiao Guozhen

    2008-01-01

    A number of methods for constructing new plateaued functions from known ones are presented. By properly combining the known plateaued functions it is possible to get highly nonlinear resilient plateaued functions. The order, resiliency and propagation characteristics of the constructed plateaued functions are discussed. We show the new functions could possess the desirable cryptographic property.

  2. Research on Honing System with Different Spindles%基于不同安装主轴类型的珩磨系统

    Institute of Scientific and Technical Information of China (English)

    肖飞来

    2001-01-01

    从珩磨机床在国内目前应用情况,分析珩磨加工原理,基于两种不同主轴的珩磨系统,根据各种零件的自身特点,试图找出某种内在规律,以期为相关厂家在珩磨设备选型时提供一定的依据,达到节省选型时间和投资者的利益最大化。%The paper introduces several of honing machine and application in the machine work field.The principle of honing system Analyzed,on the basis of the different installed spindles of honing system and characteristic of the all kinds of workpiece. It is helpful for customer to select suitable honing machine with high efficiently and low cost.

  3. Crystal structure of 3-amino-2-propylquinazolin-4(3H-one

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Hiti

    2015-08-01

    Full Text Available In the title molecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H-one mean plane, making a dihedral angle of 88.98 (9°. In the crystal, molecules related by an inversion centre are paired via π–π overlap, indicated by the short distances of 3.616 (5 and 3.619 (5 Å between the centroids of the aromatic rings of neighbouring molecules. Intermolecular N—H...N and N—H...O hydrogen bonds form R66(30 rings and C(5 chains, respectively, generating a three-dimensional network. Weak C—H...O interactions are also observed.

  4. Search for anticonvulsant and analgesic active derivatives of dihydrofuran-2(3H)-one.

    Science.gov (United States)

    Więckowski, Krzysztof; Sałat, Kinga; Bytnar, Justyna; Bajda, Marek; Filipek, Barbara; Stables, James P; Malawska, Barbara

    2012-11-01

    A series of derivatives of dihydrofuran-2(3H)-one (γ-butyrolactone, GBL) was synthesized and tested for anticonvulsant, neurotoxic and analgesic activity. In the anticonvulsant screening 10 lactones were effective in the maximal electroshock test (MES) at the highest doses (300 and 100 mg/kg, 0.5 h, ip, mice). Statistical analysis showed correlation between the anticonvulsant activity and relative lipophilicity parameters determined by experimental and computational methods (R(M0), ClogP and MlogP). Preliminary antinociceptive evaluation of selected derivatives revealed strong analgesic activity. The majority of the tested compounds showed high efficacy in animal models of acute pain (hot plate and writhing tests) and strong local anesthetic activity (modified tail immersion test). The obtained ED(50) values were comparable with such analgesics as acetylsalicylic acid and morphine.

  5. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    Directory of Open Access Journals (Sweden)

    J. Bown

    2012-06-01

    Full Text Available Processes of cobalt (Co entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope current, in addition to advection of Co-enriched and low oxygenated ocean water-masses.

    In surface waters, strong sedimentary Co inputs were estimated to be much higher than biological Co uptake in phytoplankton blooms, underlining the potential role of cobalt as lithogenic tracer. Based on a simple, steady state balance equation of the external input of dissolved iron over the plateau, the fertilization of iron inferred by using Co as a tracer of basalt sources is estimated to be 28 × 102 ± 21 × 102 ton yr−1 in surface waters of the Kerguelen Plateau. This estimate is consistent with preceding ones and the required iron supply matching the phytoplankton demand.

  6. Argalis on the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The argali are listed by the State as animals subject tosecond-class protection,and no killing is allowed. The international communitylists argali on the Qinghai-Tibet Plateau as animals that must not be hunted.

  7. Colorado Plateau Rapid Ecoregion Assessment Data Catalog

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — Datasets used in the analysis of the Colorado Plateau (COP) Rapid Ecoregion Assessment (REA).They can be downloaded via a layer package (lpk, similar to a zip file...

  8. Pyramid Schemes on the Tibetan Plateau

    OpenAIRE

    Devin Gonier; Rgyal yum sgrol ma

    2012-01-01

    The unique features of pyramid schemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be ...

  9. Comparative Study on Growth Process of Main Introduced Tree Species in the Middle Loess Plateau%黄土高原中部主要引进树种生长过程分析

    Institute of Scientific and Technical Information of China (English)

    刘广全; 孙克; 何正祥; 王鸿喆

    2012-01-01

    The introduced 16 species Austrian black pine,ponderosa pine,pinyon,scotch pine,Austrian pine and so on in the middle part of the Loess Plateau,the process of the average individual height growth can be grouped into two categories,the first type represented by Austrian pine,it grows rapidly in the period of seedlings,along with the ages its growth slows down and gradually stabilizes.The other type follows the growth pattern of "show-rapid-slow-stably drop down".Its average annual growth in height is 0.369±0.097m,Ponderosa pine and Austrian pine are the highest(0.535±0.052m),and china hemlock is the lowest(0.251±0.044m).The mean current annual growth in height of the 6 species is 0.387±0.104 m,the black pine is the maximum,the huashan pine is the minimum,the former is 2.63 times of the later.The variation of the average annual growth at breast height of the above-mentioned sixteen species is not appreciable,the highest of the ponderosa pine is 1.595±0.192 cm,the lowest is Wilson spruce with variation of 0.363±0.088cm.The average annual growth at breast height of the native tree species as bunge pine,huashan pine,golden larch,Wilson spruce,china hemlock and mogol scotch pine is 0.6048 cm,compared with the introduced tree species with 0.8488cm,which growth surpass the native tree species.Among the 16 introduced tree species with the mean current annual growth of 0.7056±0.2590 cm,the ponderosa pine is the maximum(1.249±0.350cm),and Wilson spruce is the minimum(0.376±0.241cm),the introduced tree species surpass the native tree species more than 50.0%.%本文对黄土高原中部引进的奥地利黑松、美国黄松、美人松、欧洲赤松、欧洲黑松等16个树种,林分个体树高平均生长量曲线分两种类型,以欧洲黑松为代表的第一种类型,苗期生长较快,随着年龄的增加,树高平均生长量趋于减慢且逐渐稳定,另外一种类型满足正常的"慢—快—缓慢—稳中有降"的生长规

  10. DYNAMICS OF BRÂGLEZ RIVERBED (SOMEŞAN PLATEAU

    Directory of Open Access Journals (Sweden)

    V. ARGHIUŞ

    2012-03-01

    Full Text Available Dynamics of Brâglez Riverbed (Someşan Plateau. The main left tributaries of Someş along Surduc – Jibou sector (Brâglez, Almaş and Agrij, are characterized by the presence of obvious processes of lateral and vertical erosion at the level of the riverbeds. The field observations, as well as the position of these rivers and their catchment areas in the neighborhood of the lower Someş subsidence area, would easily be grounds for explaining the riverbed processes as caused by an unstable fluvial base level. More precisely, this base level would be moving downwards under the influence of subsidence movements of Tisa Plain or even because of the subsidence affecting Guruslău Basin. Starting from these more or less speculative deductions, this paper aims at checking and confirming the above-mentioned explanations or finding other causes for the dynamics of riverbed processes. In this sense, we analysed a correlation between the drainage in the catchment area and at the level of the riverbeds, on one hand, and the riverbed geomorphological processes, on the other hand. Brâglez River (in western Someşan Plateau will be considered as a study case, as it provides an accelerated dynamics of riverbed processes. This situation will be compared with the one in the eastern part of the same plateau, where rivers like Borşa, Luna or Lujerdiu do not present obvious riverbed processes despite the similar climatic and geological conditions.

  11. Mutual influence between human activities and climate change in the Tibetan Plateau during recent years

    Science.gov (United States)

    Du, Mingyuan; Kawashima, Shigeto; Yonemura, Seiichiro; Zhang, Xianzhou; Chen, Shenbin

    2004-07-01

    It is well known that there is a vast expanse of grassland on the Tibetan Plateau, China. It is suggested that a major climatic factor limiting production of the grassland ecosystem is the low thermo-conditions on the Tibetan Plateau. An increase in temperature may therefore increase the productivity of grasslands on the Plateau. Monthly mean temperature and monthly precipitation data for recent years on the Tibetan Plateau were analyzed. It is clear that the increase in air temperature on the Plateau is greater than that in the whole China and East Asia. On the other hand, statistics show that the production of livestock or meat in the Tibetan Plateau has increased by one to three times since 1978, which means that there should be an equivalent increase in the consumption of plant biomass from the grassland. How is the "increased biomass" related to human activities and climate changes? This paper tries to clarify the relationship between human activities and climate change and to propose a possible answer by laying emphasis on the importance of grassland protection and CO 2 flux monitoring. It is suggested that there is a positive feedback in which degradation of grassland by overgrazing will increase potential evapotranspiration level thereby promoting the climate warming and the degradation process. This feedback should be considered seriously in the future.

  12. Magnetostratigraphy of Late Cenozoic fossil mammals in the northeastern margin of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A number of fossil mammals have been found in the very thick Cenozoic stratigraphy of the Guide Basin in the northeastern margin of the Tibetan Plateau. Some of these are of great significance in mammal evolution and stratigraphic correlation on and around the Tibetan Plateau and North China. However, the chronology of these mammals is poorly constrained. Dating of the mammals will not only place precise age constraints on the mammals, but also provide much information on the related stratigraphy that records the uplift process of the Tibetan Plateau. Detailed paleomagnetism of the upper part of the Cenozoic stratigraphy at He'erjia and Lajigai north of Guide County has revealed magnetic chrons that can be correlated to Gauss and 3An chrons, determining the section spanning about 3.1-6.5 Ma and the first, second and third layers of fossil mammals at about 5.25, 5.1 and 4.4 Ma, respectively. Ages of the significant genus Gazella kueitensis and the Chinese elephant Anancus sinensis are firstly constrained at about 5.25 MaBP and 4.4 Ma, respectively. The mammalian evolution and the associated increase in coarse sediments and sedimentation rate may suggest that the northeastern Tibetan Plateau was uplifted rapidly at that time, and the eastern Tibetan Plateau with its neighboring regions was not high enough to stop mammal exchange between the northern and southern sides of the Tibetan Plateau.

  13. Long-term exhumation history of the Inner Mongolian Plateau constrained by apatite fission track analysis

    Science.gov (United States)

    Li, Ke; Jolivet, Marc; Zhang, Zhicheng; Li, Jianfeng; Tang, Wenhao

    2016-01-01

    The Inner Mongolian Plateau, along the southeastern flank of the wider Mongolian Plateau, is a vast undulating surface ranging in elevation between 900 and 1500 m above sea level. The peculiar topography of this area is assumed to be closely related to its complex tectono-thermal evolution since Late Paleozoic. The lithospheric structure of the Plateau includes three continental blocks: the Mandula and the Bart Obo blocks form the southern margin of the Central Asian Orogenic Belt in that area, and to the south, the Plateau includes the northern margin of the North China Craton. Apatite fission track (AFT) ages and track length distributions from 13 basement outcrops situated in the main tectonic blocks forming the Inner Mongolian Plateau were determined in order to reconstruct its denudation history. The thermal histories inferred from these data imply multi-phased, differential exhumation/burying processes from the Late Paleozoic to the Early Cretaceous. This complex thermal history is largely related to the Early/Middle Triassic closure of the Paleo-Asian Ocean, the Jurassic closure of the Mongol-Okhotsk Ocean, and the Early Cretaceous orogenic collapse of the Mongol-Okhotsk belt. Finally, since Late Cretaceous, no further major tectonic movement occurred and the Inner Mongolian Plateau has been largely peneplained.

  14. STATUS, CAUSES AND COMBATING SUGGESTIONS OF SANDY DESERTIFICATION IN QINGHAI-TIBET PLATEAU

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-hua; DONG Guang-rong; LI Sen; DONG Yu-xiang

    2005-01-01

    The Qinghai-Tibet Plateau is one of the major sandy desertification regions of China. Based on the recent investigation on sandy desertification, this paper analyses the status such as the type, area, distribution and damage of sandy land desertification in the plateau. Through the analysis on the factors affecting sandy desertification in the region's natural and socio-economic systems as well as the processes and their interrelations, it can be concluded that sandy desertification in the Qinghai-Tibet Plateau resulted from the combined actions of normal natural sand drift processes, natural sandy desertification processes caused by climatic changes and man-made sandy desertification caused by improper human activities. In addition, it also predicts the possible developmental trend including the increase in desertification area and the enhancement in desertification developmental degree with the exacerbation of the complex processes, and finally puts forward some strategic suggestions to combat sandy desertification in the coming years.

  15. 基于UG内啮合珩齿的仿真加工分析%Simulation Machining Analysis for Internal Gear Honing based on UG

    Institute of Scientific and Technical Information of China (English)

    师瑜; 赵洪鹤; 张满栋

    2013-01-01

    Internal gear honing is a process of precise machining of the gear, in the process, there exists trace amounts of interference between tooth surfaces as helical internal honing wheel and spur gear are a gear pair with crossed shaft, a crown teeth can be obtained by removing the interference amount, and the crown teeth brings great benefit for reducing noise and enhancing the stability of transmission of the gear. Because the meshing of a crossed shaft gear pair is very complex, the analytical calculation of the quantity of interference between teeth is also difficult to be achieved. By using a 3 - D modeling software UG/NX, the parameter of the cylindrical internal helical gear and the spur gear modeling and assembly simulation is realized, through the simulation of gear meshing movement, interference is successfully removed to process the crown teeth, and finally data of interference for a single tooth is obtained.%内啮合珩齿是一种齿轮精密加工的工艺方法,由于其斜齿内珩轮与直齿圆柱齿轮属于交错轴齿轮副,齿面之间存在着微量的干涉.通过去除干涉量可得到鼓形齿,而鼓形齿对于降低噪声,增强齿轮传动的平稳性都有极大的益处.由于交错轴齿轮副的啮合情况非常复杂,轮齿之间的干涉量解析计算也难以实现.为此利用三维建模软件UG/NX实现了对圆柱内斜齿轮和直齿圆柱齿轮参数建模和装配,通过模拟齿轮的啮合运动,成功将干涉部分切除加工出鼓形齿.最终得到单个齿上的干涉量.

  16. Synthesis, Biological Evaluation and Molecular Docking Studies of 6-Aryl-2-Styrylquinazolin-4(3H-Ones

    Directory of Open Access Journals (Sweden)

    Emmanuel Ndubuisi Agbo

    2015-12-01

    Full Text Available Suzuki-Miyaura cross-coupling of 6-bromo-2-styrylquinazolin-4(3H-ones with arylboronic acids afforded a series of novel 6-aryl-2-styrylquinazolin-4(3H-ones. These compounds were evaluated for potential anticancer properties against the human renal (TK-10, melanoma (UACC-62 and breast cancer (MCF-7 cell lines. Their antimicrobial properties were also evaluated against six Gram-positive and four Gram-negative bacteria, as well as two strains of fungi. Molecular docking studies (in silico were conducted on compounds 5a, b, d and 6a, b, d–f to recognize the hypothetical binding motif of the title compounds within the active site of the dihydrofolate reductase and thymidylate synthase enzymes.

  17. Synthesis and Antimicrobial Activity of Some Novel Substituted Piperazinyl-quinazolin-3(4H-ones

    Directory of Open Access Journals (Sweden)

    N. M. Raghavendra

    2008-01-01

    Full Text Available Several substituted-quinazolin-3(4H-ones were synthesized by condensation of 2-chloro-N-(4-oxo-substituted-quinazolin-3(4H-yl-acetamides with various substituted piperazines through single step reaction. Elemental analysis, IR, 1HNMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolin-4-one derivatives were investigated for their antibacterial and antifungal activities.

  18. Synthesis of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives from curcuminoids

    Institute of Scientific and Technical Information of China (English)

    Ying Peng Huo; Xu Qiu; Wei Yan Shao; Lin Kun An; Xian Zhang Bu; Lian Quan Gu

    2009-01-01

    Series of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives were synthesized in acceptable to good yields by treatment of the curcuminoids with aqueous ammonia, the mechanism was proposed. By modification of the primary products, total 13 new compounds were obtained. The structures of all products were elucidated by spectroscopy analysis including HR-MS, ~1H NMR and ~(13)C NMR.

  19. Water and ionic liquid synergy: A novel approach for the synthesis of benzothiazole-2(3H)-one

    OpenAIRE

    Malik A. Waseem; Shireen; Arjita Srivastava; Anjali Srivastava; Rahila; Siddiqui, I. R.

    2015-01-01

    Synergy between water, a green reaction medium and ionic liquid, a green catalyst has opened new vistas in the field of organic transformation. The developed methodology has emerged as an interesting combination for an environmentally benign, facile and efficient synthesis of benzothiazole-2(3H)-one. Product was achieved in excellent yield by the reaction of structurally diverse 2-iodoanilines with potassium thiocyanate. The strategy involves nucleophilic substitution forming NC and SC bond...

  20. Ceric Ion Loaded MCM-41 Catalyzed Synthesis of Substituted Mono- and Bis-dihydropyrimidin-2(1H-ones

    Directory of Open Access Journals (Sweden)

    Pullar Vadivel

    2013-01-01

    Full Text Available An effective one-pot three-component reaction of aromatic aldehydes with 1,3-diketone and urea or thiourea under solvent-free condition leads to the formation of mono- and bis-dihydropyrimidin-2-(1H-ones using Ce-MCM-41 as a recyclable solid acid catalyst. This method has several advantages like simple and easy work-up with shorter reaction time, reusability of catalyst, and high yields of Biginelli products.

  1. Characteristics of land-atmosphere energy and turbulentfluxes over the plateau steppe in central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the TibetanPlateau (TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point (BJ) of the Nagqu PlateauClimate and Environment Station (NPCE-BJ), different characteristics of the energy flux during the Asian summermonsoon (ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energyfluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than thatof the post-monsoon period. Footprint modeling shows the distribution of data quality assessments (QA) and qualitycontrols (QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly representativeof the target land-use type. The target surface contributed more to the fluxes under unstable conditions thanunder stable conditions. The main wind directions (180° and 210°) with the highest data density showed flux contributionsreaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density,e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance(SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was alsoexplored in this study. The Nash-Sutcliffe model efficiency coefficients (NSEs) of the observed fluxes with the SEWABmodel runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of?0.9 for latent heat flux during the post-monsoon period.

  2. Synthesis, characterization and In vitro antimicrobial evaluation of novel pyrazolothiazol-4(5H-one derivatives

    Directory of Open Access Journals (Sweden)

    Priyanka L Gaikwad

    2013-01-01

    Full Text Available Antimicrobial screening of several novel pyrazolothiazol-4(5H-one derivatives (3a-3j has been performed. Reaction of aromatic aldehydes with aromatic ketones yielded starting chalcones (1a-1j which have been subsequently reacted with thiosemicarbazide for obtaining N-thiocarbamoylpyrazole derivatives (2a-2j. These were further cyclized to pyrazolothiazol-4(5H-one derivatives (3a-3j in the presence of ethylbromoacetate. The structures of newly synthesized compounds were confirmed by FTIR and 1 H NMR and/or MS. The in vitro antimicrobial activity of these compounds was evaluated against Gram positive bacteria, Gram negative bacteria and fungi. Their minimum inhibitory concentration was determined by tube dilution method. The results showed that most of the compounds have promising antimicrobial activity as compared to standard drugs. Among the test compounds, 2-[5(4-chlorophenyl-3-phenyl-4,5-dihydropyrazol-1-yl]-thiazol-4(5H-one (3e was found to show the most potent antimicrobial activity.

  3. CO2 processes in an alpine grassland ecosystem on the Tibetan Plateau%青藏高原高寒草原生态系统CO2过程研究

    Institute of Scientific and Technical Information of China (English)

    裴志永; 欧阳华; 周才平

    2003-01-01

    In this paper, the CO2 concentrations profile from 1.5 m depth in soil to 32 m height in atmosphere were measured from July 2000 to July 2001 in an alpine grassland ecosystem located in the permafrost area on the Tibetan Plateau, which revealed that CO2 concentrations varied greatly during this study period. Mean concentrations during the whole experiment in the atmosphere were absolutely lower than the CO2 concentrations in soil, which resulted in CO2 emissions from the alpine steppe soil to the atmosphere. The highest CO2 concentration was found at a depth of 1.5 m in soil while the lowest CO2 concentration occurred in the atmosphere. Mean CO2 concentrations in soil generally increased with depth. This was the compositive influence of the increasing soil moistures and decreasing soil pH, which induced the increasing biological activities with depth. Temporally, the CO2 concentrations at different layers in air remained a more steady state because of the atmospheric turbulent milking. During the seasonal variations, CO2 concentrations at surface soil interface showed symmetrical patterns, with the lowest accumulation of CO2 occurring in the late winter and the highest CO2 concentration in the growing seasons.

  4. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 301 (FGE.301): A sulphur substituted pyrimidin-derivative and its hydrochloride salt

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate two flavouring substances, 4-amino-5,6-dimethylthieno[2,3-d]pyrimidin-2(1H)-one [FL-no: 16.116] and 4-amino-5,6-dimethylthieno[2,3-d]pyrimidin-2(1H)-one...

  5. Simulation Research on the Surface Residual Stress of Ultrasonic Vibration Honing%超声振动珩磨表面残余应力数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    郑华林; 张伟

    2015-01-01

    目的:磨削产生的残余应力对工件表面特性有重要影响,超声振动珩磨使磨粒具有极大的加速度而改变了材料去除机理,研究超声振动对工件表面残余应力的影响及产生机理。方法分析残余应力形成有限元理论,建立基于热弹塑性有限元法的超声振动单颗CBN磨粒切削40 CrNiMoA热力耦合有限元模型,并设置两次切削、卸载、约束转换及冷却等分析步。通过数值模拟得到不同振动参数下表面残余应力的分布情况,并对模拟结果进行分析。结果有限元计算得到的各分析阶段应力分布存在差别,超声振动参数设置达到仿真要求;对磨粒施加超声振动后珩磨力下降约26%,珩磨热降低约17%,切向残余压应力有所减小,垂直珩磨速度方向拉应力减小并向压应力转变。结论超声振动使珩磨力和珩磨热有一定程度降低从而改变了残余应力的分布及数值;振动频率在20 kHz波动时对残余应力的影响不大;磨削速度减小,切向残余压应力增大,垂直磨削方向残余拉应力减小;振幅增大时,切向残余压应力减小,垂直方向残余应力增大。%ABSTRACT:Objective To study the influence on residual stress as the grinding residual stress has important influence on work-piece surface characteristics and ultrasonic vibration honing makes the grains obtain a great acceleration which changes the material removal mechanism. Methods The residual stress finite element theory was analyzed, the coupled thermal-mechanical finite ele-ment model was established for the ultrasonic vibration honing of a single CBN grain cutting 40CrNiMoA based on the thermal elas-tic-plastic theory. Steps of two cutting processes, unloading, constraint transformation and the cooling analysis were set. The sur-face residual stress distribution was obtained by numerical simulation under different vibration parameters and the simulation results

  6. Imprint of a dissolved cobalt basaltic source on the Kerguelen Plateau

    Directory of Open Access Journals (Sweden)

    J. Bown

    2012-12-01

    Full Text Available Processes of cobalt (Co entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope current, in addition to advection of Co-enriched and low-oxygenated ocean water masses.

    In surface waters, the strong sedimentary Co inputs were estimated to be much higher than biological Co uptake in phytoplankton blooms, underlining the potential use of dissolved cobalt as tracer of the natural iron fertilization above the Kerguelen Plateau. Based on a simple steady-state balance equation of the external input of dissolved iron over the plateau, the fertilization of iron inferred by using dissolved Co as a tracer of basalt sources is estimated to be 28 × 102 ± 21 × 102 t yr−1 in surface waters of the Kerguelen Plateau. This estimate is consistent with preceding ones (Zhang et al., 2008; Chever et al., 2010, and the calculated iron supply matches with the phytoplankton demand (Sarthou et al., 2008.

  7. Relationship model of sediment grain size and Tibetan Plateau uplift in middle-west parts of Qilian Mountain

    Institute of Scientific and Technical Information of China (English)

    傅开道; 李吉均; 高军平; 方小敏

    2001-01-01

    By observing, measuring the fluvial sediment grain size of mid-western segment of the Qilianshan Range and studying the correlation between the grain size and uplift of the plateau, we model the correlation. These models are applied to the Laojunmiao section and the process curve of the uplift of the northern Tibetan Plateau against age from 8.35 Ma is illustrated here. The process curve shows that the northern Tibetan Plateau surface has uplifted from the mean altitude of 900-3700 m since 8.35 MaBP. From 8.35 to 3.1 MaBP, the Tibetan Plateau uplifted slowly, uplifted amplitude is small, the total range is 420 m. From 3.1 MaBP up to now, the Tibetan Plateau uplifted tempestuously, showing that the uplift accelerated obviously later. It uplifted totally 2400 m. About 0.9 Ma ago, the northern Tibetan Plateau surface had uplifted to over 3000 m a.s.l., showing that the Tibetan Plateau surface had reached the cryosphere; and the mountain peaks had uplifted to more than 4000 m altitude, suggesting that there

  8. The Hikurangi Plateau: Tectonic Ricochet and Accretion

    Science.gov (United States)

    Willis, David; Moresi, Louis; Betts, Peter; Whittaker, Joanne

    2015-04-01

    80 million years between interactions with different subduction systems provided time for the Hikurangi Plateau and Pacific Ocean lithosphere to cool, densify and strengthen. Neogene subduction of the Hikurangi Plateau occurring orthogonal to its Cretaceous predecessor, provides a unique opportunity to explore how changes to the physical properties of oceanic lithosphere affect subduction dynamics. We used Underworld to build mechanically consistent collision models to understand the dynamics of the two Hikurangi collisions. The Hikurangi Plateau is a ~112 Ma, 15km thick oceanic plateau that has been entrained by subduction zones immediately preceding the final break-up of Eastern Gondwana and currently within the active Hikurangi Margin. We explore why attempted subduction of the plateau has resulted in vastly different dynamics on two separate occasions. Slab break-off occured during the collision with Gondwana, currently there is apparent subduction of the plateau underneath New Zealand. At ~100Ma the young, hot Hikurangi Plateau, positively buoyant with respect to the underlying mantle, impacted a Gondwana Margin under rapid extension after the subduction of an mid-ocean ridge 10-15Ma earlier. Modelling of plateaus within young oceanic crust indicates that subduction of the thickened crust was unlikely to occur. Frontal accretion of the plateau and accompanying slab break-off is expected to have occured rapidly after its arrival. The weak, young slab was susceptible to lateral propagation of the ~1500 km window opened by the collision, and break-off would have progressed along the subduction zone inhibiting the "step-back" of the trench seen in older plates. Slab break-off coincided with a world-wide reorganisation of plate velocites, and orogenic collapse along the Gondwana margin characterised by rapid extension and thinning of the over-riding continental plate from ~60 to 30km. Following extension, Zealandia migrated to the NW until the Miocene allowing the

  9. Optical Turbulence above the Internal Antarctic Plateau

    CERN Document Server

    Masciadri, E; Hagelin, S; Moigne, P Le; Noilhan, J

    2010-01-01

    The internal antarctic plateau revealed in the last years to be a site with interesting potentialities for the astronomical applications due to the extreme dryness and low temperatures, the typical high altitude of the plateau, the weak level of turbulence in the free atmosphere down to a just few tens of meters from the ground and the thin optical turbulence layer developed at the ground. The main goal of a site testing assessment above the internal antarctic plateau is to characterize the site (optical turbulence and classical meteorological parameters) and to quantify which is the gain we might obtain with respect to equivalent astronomical observations done above mid-latitude sites to support plans for future astronomical facilities. Our group is involved, since a few years, in studies related to the assessment of this site for astronomical applications that include the characterization of the meteorological parameters and optical turbulence provided by general circulation models as well as mesoscale atmo...

  10. Crustal Flows beneath the Eastern Tibetan Plateau Revealed by Magnetotelluric Observations

    Institute of Scientific and Technical Information of China (English)

    BAI Dengha; TENG Jiwen; MA Xiaobing; KONG Xiangru

    2011-01-01

    The ongoing collision of the Indian and Asian continents has created the Himalayan and Tibetan plateau through a range of deformation processes that include crustal thickening, delamination, lateral extrusion and crustal flow. A debate continues as to which of these processes are most significant in terms of the overall mass balance of this continent-continent collision.

  11. Tectonomagmatic Associations on the Central Andean Plateau

    Science.gov (United States)

    de Silva, S. L.; Viramonte, J. G.

    2012-12-01

    The Neogene evolution of the Central Andes is characterized by a strong association between plate convergence, mountain building and plateau formation, and magmatism. Plateau uplift by crustal shortening and thickening in the lower crust is broadly coincident with large scale silicic magmatism defined by the Neogene Central Andean ignimbrite province. Of particular interest here are the spatiotemporal correlations between silicic magmatism and tectonic evolution of the Altiplano-Puna plateau. Although magmatism is driven by the subduction-related flux from mantle to crust, the shift to "crustal" magmatism as indicated by elevated crustal isotopic indices after ~10Ma suggests a link between crustal thickening, plateau formation and silicic magmatism. In particular, elevated geotherms associated with crustal thickening and enhanced mantle flux associated with lithospheric delamination may have played a role in thermally preparing the Central Andean crust for enhanced silicic magma production during the extensive Neogene ignimbrite flare-up. Emplacement of these magmas in the upper crust throughout the Neogene may have fuelled a period of significant interaction between magmatism and tectonism on the plateau. With particular reference to the 21° to 24°S segment of the Central Andes, spatial and structural coincidence of calderas of the Altiplano Puna Volcanic Complex with the NW-SE striking Calama-Olacapata-El Toro fault zone suggests significant tectonomagmatic interaction. Location of calderas suggest that these regional faults focused magma intrusion and storage, while spatially and temporally correlated eruption pulses connote a tectonic control. Indeed, current thermomechanical models of magma chamber development and eruption triggering promote a role for external triggering of "perched" upper crustal magma chambers. This might have been achieved by melt-enhanced deformation, or alternatively, significant uplift (~1km) associated with the development of large

  12. Peopling the Tibetan plateau: insights from archaeology.

    Science.gov (United States)

    Aldenderfer, Mark

    2011-01-01

    Recent studies of the genome of modern Tibetans have revealed the existence of genes thought to provide an adaptive advantage for life at high elevation. Extrapolating from this discovery, some researchers now argue that a Tibetan-Han split occurred no more than 2750 yr ago. This date is implausible, and in this paper I review the archaeological data from the Tibetan plateau as one means by which to examine the veracity of this assertion. Following a review of the general state of knowledge of Tibetan prehistory, which is unfortunately only at its beginnings, I first examine the data that speak to the initial peopling of the plateau and assess the evidence that traces of their presence can be seen in modern Tibetans today. Although the data are sparse, both archaeology and genetics suggest that the plateau was occupied in the Late Pleistocene, perhaps as early as 30,000 yr ago, and that these early peoples have left a genetic signature in modern Tibetans. I then turn to the evidence for later migrations and focus on the question of the timing of the establishment of permanent settled villages on the plateau. Three areas of the plateau-northeastern Qinghai, extreme eastern Tibet, and the Yarlung Tsangpo valley-have evidence of permanent settlements dating from ca. 6500, 5900, and 3750 yr ago, respectively. These data are not consonant with the 2750 yr ago date for the split and suggest at a minimum that the plateau has been occupied substantially longer and, further, that multiple migrations at different times and from different places have created a complex mosaic of population history. © Mary Ann Liebert, Inc.

  13. Plateau-insulator transition in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Amado, M; Diez, E; Caridad, J M [Laboratorio de Bajas Temperaturas, Universidad de Salamanca, E-37008 Salamanca (Spain); Lopez-Romero, D [CT-ISOM, Universidad Politecnica de Madrid, E-28040 Madrid (Spain); Rossella, F; Dionigi, F; Bellani, V [Dipartimento di Fisica ' A Volta' and CNISM, Universita degli studi di Pavia, I-27100 Pavia (Italy); Maude, D K, E-mail: marioam@fis.ucm.e [Laboratoire National des Champs Magnetiques Intenses, F-38042 Grenoble (France)

    2010-05-15

    We investigate the quantum Hall effect (QHE) in a graphene sample with Hall-bar geometry close to the Dirac point at high magnetic fields up to 28 T. We have discovered a plateau-insulator quantum phase transition passing from the last plateau for the integer QHE in graphene to an insulator regime {nu}=-2{yields}{nu}=0. The analysis of the temperature dependence of the longitudinal resistance gives a value for the critical exponent associated with the transition equal to {kappa}=0.58{+-}0.03.

  14. Environmentally Benign Syntheses and Characterization of 4- Aryldihydropyrimidin-2(1H-ones

    Directory of Open Access Journals (Sweden)

    Shafqat Syed Salman

    2017-01-01

    Full Text Available A general, simple, efficient, cost-effective and environmental benign procedure for the syntheses of 4-aryl-3,4-dihydropyrimidin-2(1H-ones (DHPMs has been developed. The reaction is efficiently catalysed by using various amino acids viz., glycine, L-proline, L-cysteine, leucine and tryptophan. Reactions give excellent yields under reflux conditions. The chemical structures of these compounds were identified by Fourier Transform-Infra Red Spectroscopy (FT-IR, Gas Chromatography-Mass Spectroscopy (GC-MS and Nuclear Magnetic Resonance Spectroscopy (1H NMR. Physical parameters such as m.p., mixed m.p. as well as TLC also helped to characterize the expected products. The progress of the reaction time and purity was checked by TLC and the products were purified by recrystallization using ethyl acetate as a solvent. The synthesized molecule has numerous biological applications as it is anti-microbial, anti-inflammatory and anti-hypertensive in character.

  15. Plateau iris Íris em platô

    Directory of Open Access Journals (Sweden)

    Alberto Diniz Filho

    2008-10-01

    Full Text Available The term plateau iris was first coined in 1958 to describe the iris configuration of a patient. Two years later the concept of plateau iris was published. In 1977, the plateau iris configuration was classically defined as presurgical changes of an eye with a relative normal central anterior chamber depth, flat iris by conventional biomicroscopy, but displaying an extremely narrow or closed angle on gonioscopic examination. On the other hand, the plateau iris syndrome was defined as an acute glaucoma crisis in one eye with a relative normal central anterior chamber depth and patent iridotomy on direct examination, presenting angle closure confirmed by gonioscopic examination after mydriasis. In 1992, the anatomic aspects of plateau iris were studied using ultrasound biomicroscopy. Finally, plateau iris has been considered an anatomic variant of iris structure in which the iris periphery angulates sharply forward from its insertion point and then again angulates sharply and centrally backward, along with an anterior positioning of the ciliary processes seen on ultrasound biomicroscopy. The clinical treatment of plateau iris syndrome is carried out with topical use of pilocarpine. However, the definitive treatment should be fulfilled by performing an argon laser peripheral iridoplasty.O termo íris em platô foi primeiramente inventado em 1958 para descrever a configuração da íris de um paciente. Dois anos depois o conceito de íris em platô foi publicado. Em 1977, a configuração de íris em platô foi classicamente definida como alterações pré-cirúrgicas de um olho com uma profundidade de câmara anterior relativamente normal, íris plana pela biomicroscopia convencional, mas mostrando um ângulo extremamente estreito ou fechado pela gonioscopia. Por outro lado, a síndrome de íris em platô foi definida como uma crise de glaucoma agudo em um olho com uma profundidade de câmara anterior relativamente normal e uma iridectomia patente ao

  16. A Comparative Study of the Electrical Structure of Circum Tibetan Plateau Orogenic Belts and its Tectonic Implications

    Science.gov (United States)

    Jin, Sheng; Zhang, Letian; Wei, Wenbo; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

    2017-04-01

    The Tibetan Plateau, as known as "roof of the world", was created through the on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma. As the process continues, the plateau is growing both vertically and horizontally. The horizontal expansion of the plateau is blocked by the Yangtze block in the east, the Tarim block in the north, and the Ordos block in the northeast, and consequently lead to the formation of the circum Tibetan plateau orogenic belts. To better understand the mechanism behind this process, we conducted a comparative study by collecting 7 magnetotelluric (MT) profiles over the margins of the Tibetan plateau, namely, the INDEPTH 100, 700 and 800 lines in the southern Tibet, the INDEPTH 4000 and 5000 lines across the Altyn Tagh fault on the northern margin of the plateau, as well as other two profiles across the Haiyuan fault and the Longmenshan fault on the northeastern and eastern margins of the plateau deployed under the framework of project SinoProbe. The electrical features of the stable blocks surrounding the Tibetan plateau are generally resistive, while crustal conductive layers are found to be wide spread within the plateau. The southern margin of the Tibetan plateau is characterized by large scale underthrust of the Indian lithosphere beneath the plateau. This intense converging process created the thrust fault system distributed along the southern margin of the Tibetan plateau over 1000 km. Crustal conductive layers discovered in southern Tibet are generally associated with the southward crustal flow that originated from the lower crust within the plateau and exhumed along the thrust belts in the Himalayas. On the eastern margin of the Tibetan plateau, the electrical structures suggest that the Yangtze block wedged into the Tibetan lithosphere and caused decoupling between the crust and upper mantel. Large scale conductors discovered beneath the Songpan-Ganze block reflect that the eastward crustal flow was

  17. 珩磨工具用中温钎焊材料的研制%Development of moderate temperature brazing filler metals for honing tools

    Institute of Scientific and Technical Information of China (English)

    杨继东; 裴夤崟; 龙伟民; 钟素娟

    2011-01-01

    For the present brazing problems on the honing segments, joining experiment on the honing segments was conducted by moderate temperature brazing. The compositions of moderate temperature brazing filler metals were adjusted, melting temperature of filler metals, wettability of filler metals on the honing segments and the tensile strength of brazing joints were tested. The deformation amount of brazed honing segments with different filler metals was compared. The research results showed that the moderate temperature brazing technology had small deformation and high tensile strength, and it was a feasible mode for joining of honing segments.%针对目前珩磨条钎焊存在的问题,采用中温钎焊对珩磨工具进行了连接试验,对中温钎焊用钎料的化学成分进行了调整,测试了钎料的熔化温度、钎料对珩磨条的润湿性以及钎焊接头的抗拉强度,并比较了不同钎料钎焊后珩磨工具的变形量.研究表明:中温钎焊工艺变形小,强度较高,是珩磨条连接的可行方式.

  18. Synthesis and Antibacterial Activity of 3-(Substituted)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one.

    Science.gov (United States)

    Appani, Ramgopal; Bhukya, Baburao; Gangarapu, Kiran

    2016-01-01

    A series of novel 3-(substituted)-2-(substituted quinazolinylamino)quinazolin-4(3H)-ones were synthesized by the reaction of 3-(substituted)-2-hydrazino-quinazoline-4(3H)-ones with 2-phenyl-3,1-benzoxazin-4-one. The starting materials 3-(substituted)-2-hydrazino-quinazolin-4(3H)-ones were synthesized from various primary amines by a multistep synthesis. All the title compounds were tested for their antibacterial activity using ciprofloxacin as reference standard. Compounds 3-(4-fluorophenyl)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one (9a) and 3-(4-chlorophenyl)-2-(4-oxo-2-phenylquinazolin-3(4H)-ylamino)quinazolin-4(3H)-one (9h) emerged as the most active compounds of the series. These compounds have shown most potent antibacterial activity against the tested organisms of Proteus vulgaris and Bacillus subtilis having zone of inhibition values of 1.1 cm and 1.4 cm for compound 9a 1.2 cm and 1.0 cm for compound 9h, respectively.

  19. Synthesis and Antibacterial Activity of 3-(Substituted-2-(4-oxo-2-phenylquinazolin-3(4H-ylaminoquinazolin-4(3H-one

    Directory of Open Access Journals (Sweden)

    Ramgopal Appani

    2016-01-01

    Full Text Available A series of novel 3-(substituted-2-(substituted quinazolinylaminoquinazolin-4(3H-ones were synthesized by the reaction of 3-(substituted-2-hydrazino-quinazoline-4(3H-ones with 2-phenyl-3,1-benzoxazin-4-one. The starting materials 3-(substituted-2-hydrazino-quinazolin-4(3H-ones were synthesized from various primary amines by a multistep synthesis. All the title compounds were tested for their antibacterial activity using ciprofloxacin as reference standard. Compounds 3-(4-fluorophenyl-2-(4-oxo-2-phenylquinazolin-3(4H-ylaminoquinazolin-4(3H-one (9a and 3-(4-chlorophenyl-2-(4-oxo-2-phenylquinazolin-3(4H-ylaminoquinazolin-4(3H-one (9h emerged as the most active compounds of the series. These compounds have shown most potent antibacterial activity against the tested organisms of Proteus vulgaris and Bacillus subtilis having zone of inhibition values of 1.1 cm and 1.4 cm for compound 9a 1.2 cm and 1.0 cm for compound 9h, respectively.

  20. Continuing Colorado plateau uplift by delamination-style convective lithospheric downwelling.

    Science.gov (United States)

    Levander, A; Schmandt, B; Miller, M S; Liu, K; Karlstrom, K E; Crow, R S; Lee, C-T A; Humphreys, E D

    2011-04-28

    The Colorado plateau is a large, tectonically intact, physiographic province in the southwestern North American Cordillera that stands at ∼1,800-2,000 m elevation and has long been thought to be in isostatic equilibrium. The origin of these high elevations is unclear because unlike the surrounding provinces, which have undergone significant Cretaceous-Palaeogene compressional deformation followed by Neogene extensional deformation, the Colorado plateau is largely internally undeformed. Here we combine new seismic tomography and receiver function images to resolve a vertical high-seismic-velocity anomaly beneath the west-central plateau that extends more than 200 km in depth. The upper surface of this anomaly is seismically defined by a dipping interface extending from the lower crust to depths of 70-90 km. The base of the continental crust above the anomaly has a similar shape, with an elevated Moho. We interpret these seismic structures as a continuing regional, delamination-style foundering of lower crust and continental lithosphere. This implies that Pliocene (2.6-5.3 Myr ago) uplift of the plateau and the magmatism on its margins are intimately tied to continuing deep lithospheric processes. Petrologic and geochemical observations indicate that late Cretaceous-Palaeogene (∼90-40 Myr ago) low-angle subduction hydrated and probably weakened much of the Proterozoic tectospheric mantle beneath the Colorado plateau. We suggest that mid-Cenozoic (∼35-25 Myr ago) to Recent magmatic infiltration subsequently imparted negative compositional buoyancy to the base and sides of the Colorado plateau upper mantle, triggering downwelling. The patterns of magmatic activity suggest that previous such events have progressively removed the Colorado plateau lithosphere inward from its margins, and have driven uplift. Using Grand Canyon incision rates and Pliocene basaltic volcanism patterns, we suggest that this particular event has been active over the past ∼6 Myr.

  1. FINAL FRONTIER AT HANFORD TACKLING THE CENTRAL PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    GERBER MS

    2008-03-04

    The large land area in the center of the vast Department of Energy (DOE) Hanford Site in southeast Washington State is known as 'the plateau'--aptly named because its surface elevations are 250-300 feet above the groundwater table. By contrast, areas on the 585-square mile Site that border the Columbia River sit just 30-80 feet above the water table. The Central Plateau, which covers an ellipse of approximately 70 square miles, contains Hanford's radiochemical reprocessing areas--the 200 East and 200 West Areas--and includes the most highly radioactive waste and contaminated facilities on the Site. Five 'canyons' where chemical processes were used to separate out plutonium (Pu), 884 identified soil waste sites (including approximately 50 miles of solid waste burial trenches), more than 900 structures, and all of Hanford's liquid waste storage tanks reside in the Central Plateau. (Notes: Canyons is a nickname given by Hanford workers to the chemical reprocessing facilities. The 177, underground waste tanks at Hanford comprise a separate work scope and are not under Fluor's management). Fluor Hanford, a DOE prime cleanup contractor at the Site for the past 12 years, has moved aggressively to investigate Central Plateau waste sites in the last few years, digging more than 500 boreholes, test pits, direct soil 'pushes' or drive points; logging geophysical data sets; and performing electrical-resistivity scans (a non-intrusive technique that maps patterns of sub-surface soil conductivity). The goal is to identify areas of contamination areas in soil and solid waste sites, so that cost-effective and appropriate decisions on remediation can be made. In 2007, Fluor developed a new work plan for DOE that added 238 soil waste-site characterization activities in the Central Plateau during fiscal years (FYs) 2007-2010. This number represents a 50 percent increase over similar work previously done in central Hanford. Work Plans are

  2. Sino-Japanese Teamwork Probes Environment Changes on Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ With the support of a CAS project on Holocene environmental changes and their influences on the ecosystem of the Tibetan Plateau, a research group headed by Prof. Zhu Liping from the CAS Institute of Tibetan Plateau Research and their Japanese collaborators carried out a field survey in Puma Yumco area on the Tibetan Plateau from September 8 to 20.

  3. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent

    2015-01-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau

  4. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent

    2015-01-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau in

  5. Ozone Minihole Found over Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Through a comprehensive analysis, researchers from the CAS Institute of Atmospheric Physics (IAP) discovered an ozone minihole, a large area with the lowest total ozone column (TOC, see figure), over the Qinghai-Tibet Plateau from Dec. 14 to 17, 2003.

  6. Construction of plateaued functions satisfying multiple criteria

    Institute of Scientific and Technical Information of China (English)

    Zhang Weiguo

    2005-01-01

    A class of plateaued functions has been got by using the Maiorana-McFarland construction. A variety of desirable criteria for functions with cryptographic application could be satisfied: balancedness, high nonlinearity, correlation immunity of reasonably high order, strict avalanche criterion, non-existence of non-zero linear structures, good global avalanche characteristics, etc.

  7. Planation Surfaces on the Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold (T), the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate (U) is equal to or less than the threshold rate (U ≤ T), the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are fiat plains or deeply dissected mountains. If U > T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than 100m and the slopes are gentle at a gradient of <200. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

  8. Monte Carlo study of half-magnetization plateau and magnetic phase diagram in pyrochlore antiferromagnetic Heisenberg model

    OpenAIRE

    Motome, Yukitoshi; Penc, Karlo; Shannon, Nic

    2005-01-01

    The antiferromagnetic Heisenberg model on a pyrochlore lattice under external magnetic field is studied by classical Monte Carlo simulation. The model includes bilinear and biquadratic interactions; the latter effectively describes the coupling to lattice distortions. The magnetization process shows a half-magnetization plateau at low temperatures, accompanied with strong suppression of the magnetic susceptibility. Temperature dependence of the plateau behavior is clarified. Finite-temperatur...

  9. 6-Benzyl-3,4-dimethoxy-10-methylpyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H-one

    Directory of Open Access Journals (Sweden)

    Kathrin Meindl

    2009-10-01

    Full Text Available Pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H-ones such as the title compound, C24H21N3O3, can be obtained in a few minutes in a microwave-assisted three-component reaction from 2-aminopyridines, isocyanides and 2-carboxybenzaldehydes. In the title compound, the pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H-one ring system is almost planar (mean deviation 0.068 Å. The dihedral angle between the benzyl ring and the pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5(6H-one ring system is 78.2°. The crystal structure is stabilized by intermolecular C—H...O and C—H...N hydrogen bonds.

  10. Magnetic properties of Jiaxian red clay sequences from northern Chinese Loess Plateau and its paleoclimatic significance

    Institute of Scientific and Technical Information of China (English)

    QIANG; Xiaoke; AN; Zhisheng; LI; Huamei; CHANG; Hong

    2005-01-01

    Detailed rock magnetism investigation of the Jiaxian red clay sequences indicated that there are common magnetic mineralogy properties in red clay and loess-paleosol sequences from the Chinese Loess Plateau as well as the marked properties of themselves, magnetic minerals mainly with magnetite, maghemite, hematite, and possibly limonite/goethite contributing to the magnetic behavior. Meanwhile, it is found that the strong paleosol in red clay sequences has a lower coercivity and higher content of ultra-fine ferrimagnetic grains than that of the weak paleosol, which is similar to loess and paleosol in upper Wucheng Loess sequences, and indicates that humid conditions and relatively strong pedogenesis play a significant role in the increase of ultra-fine magnetic minerals and transformation of the magnetic minerals. This suggests that, like Quaternary loess-paleosols, the change of characteristics of paleoclimatic conditions of the late Tertiary red clay deposits is fluctuant. In addition, the results of magnetic hysteresis properties show that the applied saturated field for samples from the Jiaxian red clay sequences is higher than that of the samples from eastern and southern Chinese Loess Plateau. It is obviously shown that there exist more hard magnetic minerals and relatively weak biochemical processes in the Jiaxian red clay sequences on northern Chinese Loess Plateau. We conclude that the paleoclimatic environment is different between northern and eastern/southern Chinese Loess Plateau, and it should be more arid in northern Chinese Loess Plateau.

  11. The Cenozoic mantle magmatism and motion of lithosphere on the north margin of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    罗照华; 肖序常; 曹永清; 莫宣学; 苏尚国; 邓晋福; 张文会

    2001-01-01

    Geodynamic properties and evolution of the lithosphere on the north margin of the Tibetan Plateau are recently hot topics to geoscientists in the world. Have the northern plates been subducting underneath the Plateau? It is still an unsolved problem. One of the keys to solving this problem is to understand the genetic processes of Cenozoic magmas on the north margin of the Tibetan Plateau. However, there is no enough evidence supporting the subduction model. In contrast, a series of evidence indicates that collision-induced huge shearing faults and large-scale crust shortening played a main role in lithosphere motion on the north margin of the Tibetan Plateau. The mantle-derived igneous rocks strictly distribute at the intersections of large strike-slip faults on the north margin of the Plateau. Generation of magmas may be related to local exten-sional condition induced by strike-slipping faults, which lead to lithosphere gravitational instability and collapse, as well as upwelling of the deep hot materi

  12. 陇中黄土高原自然植被下垫面陆面过程及其参数对降水波动的气候响应%Responses of the land-surface process and its parameters over the natural vegetation underlying surface of the middle of Gansu in loess plateau to precipitation fluctuation

    Institute of Scientific and Technical Information of China (English)

    张强; 李宏宇; 张立阳; 岳平; 史晋森

    2013-01-01

    作为气候敏感区和生态脆弱区,黄土高原地区的陆面物理过程受气候波动影响十分明显.目前,虽然对黄土高原特定气候条件下的陆面物理过程有了一定认识,但对其随气候波动的动态变化规律认识却非常有限.本文利用黄土高原陆面过程观测试验在陇中黄土高原榆中SACOL站5年多的观测资料,系统分析了该地区自然植被下垫面陆面水分收支和能量平衡及地表反照率、土壤热传导率和粗糙度长度等陆面过程参数对气候波动的响应规律,发现陇中黄土高原自然植被下垫面的陆面过程特征及其参数对降水的气候波动十分敏感,不仅对降水量波动响应显著,而且与降水性质也密切相关.土壤湿度并不完全随年总降水量波动,而是随有效降水量增加而增大;陆面水分收支和土壤水分收支也随有效降水量波动变化明显;近地层垂直感热平流通量随年总降水量增加而减弱,地表能量不平衡差额却随年总降水量增加而增大.夏半年平均反照率随有效降水量增加而减小,但全年平均地表反照率却受冬季积雪时数影响十分明显,而且随积雪时数增加而增大;土壤热传导率和粗糙度长度均随年有效降水量增加而增加.并且,降水量越小,陆面过程参数对降水波动的响应就越敏感.不过,陆面过程参数基本在荒漠气候平均值和农田气候平均值之间波动,并没有突破气候约束,能够用拟合关系来表示它们对降水因子波动的响应规律,这种动态参数化关系可用来改善以往数值模拟或微气象分析时由于使用非动态陆面过程参数所带来的误差.%The Loess Plateau is well known as a specific region sensitive to global climate change, and thus its land-surface process is significantly influenced by climatic fluctuation. Up to now, the land-surface physical process over the Loess Plateau has been basically understood under a

  13. Structure Optimization of Large Double Feed Honing Stone Bridge%大型双进给珩磨头油石座的结构优化∗

    Institute of Scientific and Technical Information of China (English)

    侯运丰; 廖秋岩; 张龙波; 樊思敏

    2015-01-01

    对于大型珩磨机的珩磨头,珩磨头的刚度大小主要依靠油石座等零件的刚度大小来衡量。文章以大型双进给珩磨头油石座为研究对象,运用ANSYS软件对直径为ϕ400 mm的大型珩磨头油石座进行刚度模拟计算,在保证油石座基本尺寸不变的情况下,进行结构优化,并通过材料力学的理论计算验证其正确性,进而采用模拟计算与理论计算对比的方法,得出最佳油石座导向支柱数量为四个的结论,最终得出刚度优化方案,为大型珩磨头油石座刚度优化设计研究提供了参考。%For large honing head of honing machine, the rigidity of the honing head size mainly rely on oil-stone seat stiffness measured size. Based on the large double feed honing stone bridge as the research object, by using the ANSYS software to a diameter of 400 mm large honing stone stiffness simulation calculation, in guarantee under the condition of invariable oilstone seat basic size, structure optimization, and its correctness is proved by the theory of mechanics of materials, then adopt the method of simulation compared with the theoretical calculation, it is concluded that the best oilstone seat number for the four pillars of the conclu-sion, finally concluded that stiffness optimization scheme, for large honing stone bridge rigidity as reference for optimizing design and research.

  14. Soil erosion and management on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Loess Plateau is well known to the world for its intense soil erosion. The root cause for river sedimentation of Yellow River (Huanghe) and its resultant "hanging river" in certain section is soil and water loss on the Loess Plateau. The Loess Plateau has a long cultivation history, hence population growth, vegetation degeneration and plugging constitute the chief reason for serious soil and water loss on Loess Plateau. This paper analyses several successful cases and failures in soil conservation, presents practical soil conservation technique and related benefit analysis, and discusses some effective methods adopted in China in soil erosion control, research directions and future perspectives on Loess Plateau.

  15. Numerical investigation of the influence of gravity on the Rayleigh-Plateau jet instability

    Science.gov (United States)

    Rosello, M.; Maîtrejean, G.; Roux, D. C. D.; Jay, P.

    2016-12-01

    Controlled jet breakup processes are commonly used in many fields of industrial applications, such as inkjet printing, spray painting, and fuel injection. Most of these applications rely on the accurate prediction of the size of droplets resulting from breakup. While many parameters influence the droplets’ size, the present study focuses on the influence of the Bond number. This dimensionless number measures the influence of body forces compared with surface tension, which usually drives the Rayleigh-Plateau instability. The present work uses numerical simulation to assess the influence of the Bond number on both main droplets and satellites issuing from the Rayleigh-Plateau instability jet.

  16. Controlling and Optimization of the Honing Trajectory%珩磨轨迹的控制与优化

    Institute of Scientific and Technical Information of China (English)

    赵玉祥; 马戎; 秦继宏; 张雪萍; 姚振强

    2014-01-01

    基于对四种不同形状缸孔的统计分析,对缸孔-活塞摩擦副的摩擦功进行仿真计算,发现腰鼓形缸孔所对应的摩擦功最小,且随着缸孔截面尺寸差异程度的增大而增大。对缸孔珩磨轨迹进行重构分析,揭示了分布轨迹中间密集两端稀疏的规律,提出了油石错位安装的珩磨头结构,以提高缸孔的形状精度。建立了珩磨轨迹分布与珩磨去除量的转换关系,基于对圆柱度的数值仿真计算,证明了该方法能有效控制并优化珩磨轨迹,提高缸孔的形状精度。%This paper computes the friction work of the cylinder hole-piston friction pair by means of simula-tion and finds that the drum-shaped cylinder hole has the minimum friction work, which increases with the rise of the cross section diameters’ difference, based on the statistics of four typical cylinder hole shapes. Through reconstruction and analysis of the honing trajectory, the paper reveals that the distribution is sparse on both end and intense in the middle. Also the paper develops a honing head with dislocated stones who can overcome the defect and improve the shape precision. This paper establishes the conversion relation between the honing trajectory distribution and material removal amount. The numerical simulation of the cylindricity verifies that this method can effectively improve the cylinder hole shape precision.

  17. Solid-phase synthesis of a 6-phenylquinolin-2(1H)-one library directed toward nuclear hormone receptors.

    Science.gov (United States)

    Ruda, Marcus; Kann, Nina; Gordon, Sandra; Bergman, Jan; Nelson, William; Agback, Peter; Hagberg, Lars; Koehler, Konrad F

    2005-01-01

    A library of 6-phenylquinolin-2(1H)-ones with diversity at position 1 and the ortho, meta, and para positions of the pendant phenyl ring has been synthesized using solid-phase parallel synthetic techniques. A key step in the synthesis of the library is a tandem alkylation cleavage in which diversity can be introduced at position 1 simultaneously to the cleavage from the resin. The yields of this step were significantly improved over what has previously been reported by addition of cesium carbonate to scavenge the acid that is formed during the reaction. Furthermore, we have shown that the solid support linkage is tolerant to Suzuki coupling and etherification reaction conditions and that selective cleavage of the linkage can take place in the presence of esters. The resulting 6-phenylquinolin-2(1H)-one library was screened against a panel of nuclear hormone receptors (androgen, estrogen alpha and beta isoforms, glucocorticoid, mineralocorticoid, and progesterone). Certain members of this library display moderate affinity for several of these receptors, and consequently, the 6-phenylquinolin-2(1H)-one core of the library may be considered a privileged structure for nuclear hormone receptors. In contrast, other members of the library display high selectivity for a particular receptor. The highest affinity ligand (9{2,1,1}) possesses an affinity of 330 nM for the androgen receptor, whereas the most selective ligand (9{2,4,1}) displays an affinity of 900 nM for the androgen receptor and a selectivity of 140-fold over the next highest affinity receptor.

  18. Enantioselectivity of recombinant Rhizomucor miehei lipase in the ring opening of oxazolin-5(4H)-ones.

    Science.gov (United States)

    Turner, N A; Gaskin, D J; Yagnik, A T; Littlechild, J A; Vulfson, E N

    2001-04-01

    Enantioselectivity of enzyme catalysis is often rationalized via active site models. These models are constructed on the basis of comparing the enantiomeric excess of product observed in a series of reactions which are conducted with a range of homologous substrates, typically carrying various side chain substitutions. Surprisingly the practical application of these simple but informative 'pocket size' models has been rarely tested in genetic engineering experiments. In this paper we report the construction, purification and enantioselectivity of two recombinant Rhizomucor miehei lipases which were designed to check the validity of such a model in reactions of ring opening of oxazolin-5(4H)-ones.

  19. Facile synthetic approach for 5-aryl-9-hydroxypyrano [3,2-f] indole-2(8H-one

    Directory of Open Access Journals (Sweden)

    Cheng Wang

    2016-11-01

    Full Text Available An appropriate method for the synthesis of 5-aryl-9-hydroxypyrano[3,2-f]indole-2(8H-one was described. The targeted compounds were obtained starting from vanillin via nine steps. Interestingly, in the final cyclization step, the intermediate 4-(2-halogeno phenyl-7-methoxy-1H-indole-6-yl propiolate could convert directly into the final product in one step reaction using PtCl4 or Pd(PPh34/trifluoroacetic acid as catalysts. The possible catalytic mechanism for PtCl4 and Pd(PPh34/trifluoroacetic acid was discussed.

  20. Spectral Properties of Novel 1,3-oxazol-5(4H)-ones With Substituted Benzylidene and Phenyl Rings

    DEFF Research Database (Denmark)

    Palcut, Marián

    2009-01-01

    In the present work, five novel (4Z)-4-benzylidene-2-phenyl-1,3-oxazol-5(4H)-ones (azlactones) were investigated by the infra-red (IR) and nuclear magnetic resonance spectroscopy (NMR) of the 1H and 13C nuclei. The spectral properties of the oxazolone ring were monitored with respect...... to the substituents at the benzylidene and phenyl rings. The compounds were prepared by the Erlenmeyer–Plöchl synthesis from the respective substituted aldehydes and hippuric acid. The IR absorption spectra, measured in chlorophorm, showed a clear splitting of the vibration band in the region characteristic...

  1. Synthesis, Characterization and Single Crystal Studies of 3-cyclopropyl-3, 4-dihydroquinazolin-2(1H-one

    Directory of Open Access Journals (Sweden)

    Nitinkumar S. Shetty

    2016-10-01

    Full Text Available The paper describes industrially scalable synthesis and single crystal studies of 3-cyclopropyl-3,4-dihydroquinazolin-2(1H-one4, a versatile intermediate in the synthesis of number of biologically active compounds. The target compound has been characterized by LC-MS, 1H NMR and IR. The crystal structure analysis shows that the title compound crystallizes in monoclinic classunder the space groupP 1 21/n 1with cell parameters, a = 10.273(2 Å, b = 8.3227(19 Å, c = 11.623(3 Å, β = 104.980(3°, V = 960.0(4 Å3and Z=4.

  2. 2-(2-Hydroxypropan-2-yl-6-(prop-2-ynyloxy-1-benzofuran-3(2H-one

    Directory of Open Access Journals (Sweden)

    Henok H. Kinfe

    2012-12-01

    Full Text Available In the title compound, C14H14O4, the prop-2-ynyloxy O—C—C[triple-bond]C plane [maximum deviation = 0.0116 (12 Å] forms a dihedral angle of 78.44 (9° with the benzofuran-3(2H-one ring system. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming a tape along the a-axis direction. C—H...O interactions are observed between the tapes.

  3. Synthesis and Characterization of a Novel Copoly(aryl ether ketone) Containing 4, 4'-Biphenyl-bis[4-phthalazin-1(2H)-one] Moiety

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new monomer of 4, 4'-biphenyl-bis[4-phthalazin-1(2H)-one] was synthesized from biphenyl and phthalic anhydride, and a novel copoly(aryl ether ketone) (PPEK) was synthesized from 2, 2-bis(4-hydroxyphenyl)-propane (BPA), 4, 4'-biphenyl-bis-[4-phthalazin-1(2H)-one], 4, 4'- difluorodiphenylketone (DFK). The monomer and copolymer were characterized by FT-IR and 1H-NMR. DSC and TGA were used to the novel polymer.

  4. Potassium phthalimide as efficient basic organocatalyst for the synthesis of 3,4-disubstituted isoxazol-5(4H-ones in aqueous medium

    Directory of Open Access Journals (Sweden)

    Hamzeh Kiyani

    2017-01-01

    Full Text Available Potassium phthalimide (PPI is employed as an efficient and effective basic organocatalyst for the one-pot three-component reaction of β-oxoesters with hydroxylamine hydrochloride and various aromatic aldehydes. This cyclocondensation reaction was performed in water as an environmentally benign solvent at room temperature giving 3,4-disubstituted isoxazol-5(4H-ones in good to excellent yields. PPI was found to be an effective organocatalyst for the synthesis of isoxazol-5(4H-one system. The advantages of this method are efficiency, clean, easy work-up, high yields, shorter reaction times, inexpensive, and readily available catalyst.

  5. Synthesis of 3,4-dihydro-1,8-naphthyridin-2(1H-ones via microwave-activated inverse electron-demand Diels–Alder reactions

    Directory of Open Access Journals (Sweden)

    Salah Fadel

    2014-01-01

    Full Text Available Substituted 3,4-dihydro-1,8-naphthyridin-2(1H-ones have been synthesized with the inverse electron-demand Diels–Alder reaction from 1,2,4-triazines bearing an acylamino group with a terminal alkyne side chain. Alkynes were first subjected to the Sonogashira cross-coupling reaction with aryl halides, the product of which then underwent an intramolecular inverse electron-demand Diels–Alder reaction to yield 5-aryl-3,4-dihydro-1,8-naphthyridin-2(1H-ones by an efficient synthetic route.

  6. One-Pot Cascade Synthesis of Quinazolin-4(3H)-ones via Nickel-Catalyzed Dehydrogenative Coupling of o-Aminobenzamides with Alcohols.

    Science.gov (United States)

    Parua, Seuli; Das, Siuli; Sikari, Rina; Sinha, Suman; Paul, Nanda D

    2017-07-21

    In this paper, we report a general, efficient, and environmentally benign method for the one-pot cascade synthesis of quinazolin-4(3H)-ones via acceptorless dehydrogenative coupling of o-aminobenzamide with alcohols catalyzed by a simple Ni(II) catalyst, [Ni(MeTAA)], featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)). A wide variety of substituted quinazolin-4(3H)-ones were synthesized in high yields starting from readily available benzyl alcohols and o-aminobenzamides. Several controlled reactions along with deuterium labeling studies were carried out to establish the acceptorless dehydrogenative nature of the reactions.

  7. DNA fluorescent labeling with naphtho[1,2,3-cd]indol-6(2H)-one for investigation of protein-DNA interactions.

    Science.gov (United States)

    Vasilyeva, Svetlana V; Kuznetsov, Nikita A; Kuznetsova, Anastasya S; Khalyavina, Juliya G; Tropina, Darya A; Lavrikova, Tatyana I; Kargina, Olga I; Gornostaev, Leonid M

    2017-06-01

    Fluorescently labeled DNA to study protein-DNA interactions was synthesized using the Cu(I)-catalysed cycloaddition (CuAAC) reaction. For this purpose, a new azido-containing fluorophore based on the naphtho[1,2,3-cd]indol-6(2H)-one derivative was obtained. The fluorescent properties of naphtho[1,2,3-cd]indol-6(2H)-one derivatives and labeled DNA were studied. The new fluorescent DNA conjugate was shown to be a useful tool to study complex mechanisms of protein-DNA interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Re-evaluating the 1940s CO2 plateau

    Science.gov (United States)

    Bastos, Ana; Ciais, Philippe; Barichivich, Jonathan; Bopp, Laurent; Brovkin, Victor; Gasser, Thomas; Peng, Shushi; Pongratz, Julia; Viovy, Nicolas; Trudinger, Cathy M.

    2016-09-01

    The high-resolution CO2 record from Law Dome ice core reveals that atmospheric CO2 concentration stalled during the 1940s (so-called CO2 plateau). Since the fossil-fuel emissions did not decrease during the period, this stalling implies the persistence of a strong sink, perhaps sustained for as long as a decade or more. Double-deconvolution analyses have attributed this sink to the ocean, conceivably as a response to the very strong El Niño event in 1940-1942. However, this explanation is questionable, as recent ocean CO2 data indicate that the range of variability in the ocean sink has been rather modest in recent decades, and El Niño events have generally led to higher growth rates of atmospheric CO2 due to the offsetting terrestrial response. Here, we use the most up-to-date information on the different terms of the carbon budget: fossil-fuel emissions, four estimates of land-use change (LUC) emissions, ocean uptake from two different reconstructions, and the terrestrial sink modelled by the TRENDY project to identify the most likely causes of the 1940s plateau. We find that they greatly overestimate atmospheric CO2 growth rate during the plateau period, as well as in the 1960s, in spite of giving a plausible explanation for most of the 20th century carbon budget, especially from 1970 onwards. The mismatch between reconstructions and observations during the CO2 plateau epoch of 1940-1950 ranges between 0.9 and 2.0 Pg C yr-1, depending on the LUC dataset considered. This mismatch may be explained by (i) decadal variability in the ocean carbon sink not accounted for in the reconstructions we used, (ii) a further terrestrial sink currently missing in the estimates by land-surface models, or (iii) LUC processes not included in the current datasets. Ocean carbon models from CMIP5 indicate that natural variability in the ocean carbon sink could explain an additional 0.5 Pg C yr-1 uptake, but it is unlikely to be higher. The impact of the 1940-1942 El Niño on the

  9. Hydrogeology of the Markagunt Plateau, Southwestern Utah

    Science.gov (United States)

    Spangler, Lawrence E.

    2010-01-01

    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet and is capped primarily by Quaternary-age basalt that overlies Eocene-age freshwater limestone of the Claron Formation. Over large parts of the Markagunt Plateau, dissolution of the Claron limestone and subsequent collapse of the overlying basalt have produced a terrain characterized by sinkholes as much as 1,000 feet across and 100 feet deep. Numerous large springs discharge from the basalt and underlying limestone on the plateau, including Mammoth Spring, one of the largest springs in Utah, with a discharge that can exceed 300 cubic feet per second. Discharge from Mammoth Spring is from the Claron Formation; however, recharge to the spring largely takes place by both focused and diffuse infiltration through the basalt that caps the limestone. Results of dye tracing to Mammoth Spring indicate that recharge originates largely southwest of the spring outside of the Mammoth Creek watershed, as well as from losing reaches along Mammoth Creek. Maximum groundwater travel time to the spring from dye-tracer tests during the snowmelt runoff period was about 1 week. Specific conductance and water temperature data from the spring show an inverse relation to discharge during snowmelt runoff and rainfall events, also indicating short groundwater residence times. Results of major-ion analyses for samples collected from Mammoth and other springs on the plateau indicate calcium-bicarbonate type water containing low (less than 200 mg/L) dissolved-solids concentrations. Investigations in the Navajo Lake area along the southern margin of the plateau have shown that water losing to sinkholes bifurcates and discharges to both Cascade and Duck Creek Springs, which subsequently flow into the Virgin and Sevier River basins, respectively. Groundwater travel times to these springs, on the basis of dye tracing, were about 8.5 and 53 hours, respectively. Similarly, groundwater travel time from Duck Creek

  10. Old-field plant succession on the Pajarito Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Foxx, T.; Mullen, M.; Salisbury, M. [Los Alamos National Lab., NM (United States); Tierney, G. [Tierney (Gail), Santa Fe, NM (United States)

    1997-10-01

    Eight fallow historic fields of the ponderosa pine and pinon-juniper cover types were surveyed to determine species composition and distribution. The purpose of the study was to understand plant succession on old fields as related to mechanically manipulated sites such as material disposal areas (MDAs). Additionally, the authors wanted a listing of species on disturbed lands of the Pajarito Plateau to aide in the reclamation planning of MDAs using native species. They also wanted to determine if any species could be used as an indicator of disturbance. The eight historic fields were all within Los Alamos County, New Mexico, and had been abandoned in 1943. Two sites were within the boundaries of Los Alamos National Laboratory and were studied both in 1982 and 1993. The study provides a description of each of the field sites, historic information about the homesteads from patent applications, a photographic record of some of the sites, and a listing of species found within each field. The study showed that there were 78 different plant species found on disturbed sites. Of these 78 species, 23 were found to be dominant on one or more of the MDAs or old fields. Although, the disturbance history of each site is imperfectly known, the study does provide an indication of successional processes within disturbed sites of the Pajarito Plateau. Additionally, it provides a listing of species that will invade disturbed sites, species that may be used in site reclamation.

  11. The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The karst landforms distributed on the Qinghai-Xizang (Tibet) Plateau can be genetically classed with the Tertiary underground karst, which were gradually exhumed to the surface with the uplift of the plateau during Quaternary period. The relative deposits of the Tertiary palaeokarst processes, such as the residuum and speleothem, were discovered recently in the southern and southeastern fringe areas of the plateau, where has geological-currently been disintegrated by the headward erosion processes of the modern river systems. The major chemical components of the clay portion of the residuum consist mainly of SiO2, Al2O3 and Fe2O3. The clay minerals composition of the clay portion belongs to illite-kaolinite pattern for most of the residuum samples, and kaoliniteillite pattern for a few of the samples. It can be judged from the silicic acid index and the clay minerals composition that the formation of the residuum of the Plateau was in its initial phase.However, such a lower chemical weathering index only reflected the weathering degree in the bottom or lower parts of the lateritic weathering crust. The relatively intensive chemical weathering processes of the surface layers of the lateritic weathering crust could be logically speculated. The surface feature textures of quartz grains in the residuum were formed mainly by the chemical erosion, which revealed a long-term humid-tropical environment when the residuum and the palaeokarst formed.

  12. Effect of different process model on the compartment syndrome prevention after serious fracture of tibial plateau%不同处理方式预防严重胫骨平台骨折后骨筋膜室综合征的效果比较

    Institute of Scientific and Technical Information of China (English)

    蒋群花; 杨莹; 张秀凤; 冯洁; 沈丽

    2012-01-01

    目的 比较3种不同处理方式对预防严重胫骨平台骨折后骨筋膜室综合征的效果.方法 将90例严重胫骨平台骨折患者随机分为3组,小腿按压组患者30例给予小腿静脉按压,冰袋冷敷组患者30例给予冰袋冷敷,对照组30例进行常规护理,3组患者入院后均给予常规脱水剂快速静脉滴注.比较3组效果.结果 在骨筋膜室综合征的发生率、张力性水疱、1周内皮肤皱褶方面冰袋冷敷组与对照组比较差异有统计学意义(1比4,3比9,22比15;x2值分别为4.284,3.822,3.875;P<0.05),小腿按压组与对照组比较差异也有统计学意义(0比4,2比9,23比15;x2值分别为4.784,5.986,4.593;P <0.05);而冰袋冷敷组与小腿按压组之间差异无统计学意义(x2值分别为0.005,0.215,0.085;P>0.05).结论 早期局部冰袋冷敷和小腿静脉按压均能减轻软组织的肿胀,预防骨筋膜室综合征发生.%Objective To compare the effect of three different process models on the compartment syndrome prevention after serious fracture of tibial plateau.Methods Totals of 90 cases with serious fracture of tibial plateau were randomly divided into three groups,with 30 cases every group,crus press group received the intervention of leg vein press,cold packs group received the cold packs intervention,and the control group received the traditional nursing care.All the patents received the rapid intravenous drip of dehydrant.Results The incidence of compartment syndrome,tension sex blisters,skin folds in one week of cold packs group was significantly different with that of control group( 1 vs 4,3 vs 9,22 vs 15;x2 =4.284,3.822,3.875,respectively;P < 0.05 ),and between crus press group and control group,the difference was statistically significant (0 vs 4,2 vs 9,23 vs 15; x2 =4.784,5.986,4.593,respectively; P < 0.05 ),while there was no significantly difference between cold packs group and crus press group( P > 0.05 ).Conclusions The process model of

  13. Improvement of antibacterial activity of some sulfa drugs through linkage to certain phthalazin-1(2H)-one scaffolds.

    Science.gov (United States)

    Ibrahim, Hany S; Eldehna, Wagdy M; Abdel-Aziz, Hatem A; Elaasser, Mahmoud M; Abdel-Aziz, Marwa M

    2014-10-06

    RAB1 5 is a lead antibacterial agent in which trimethoprim is linked to phthalazine moiety. Similarly, our strategy in this research depends on the interconnection between some sulfa drugs and certain phthalazin-1(2H)-one scaffolds in an attempt to enhance their antibacterial activity. This approach was achieved through the combination of 4-substituted phthalazin-1(2H)-ones 9a, b or 14a, b with sulfanilamide 1a, sulfathiazole 1b or sulfadiazine 1c through amide linkers 6a, b to produce the target compounds 10a-d and 15a-e, respectively. The antibacterial activity of the newly synthesized compounds showed that all tested compounds have antibacterial activity higher than that of their reference sulfa drugs 1a-c. Compound 10c represented the highest antibacterial activity against Gram-positive bacteria Streptococcus pneumonia and Staphylococcus aureus with MIC = 0.39 μmol/mL. Moreover, compound 10d displayed excellent antibacterial activity against Gram-negative bacteria Escherichia coli and Salmonella typhimurium with MIC = 0.39 and 0.78 μmol/mL, respectively.

  14. Structural and spectroscopic studies of bis(2-amino-6-methylpyrimidinium-4-(1H)-one) aquapentachloridoindate(III) monohydrate

    Science.gov (United States)

    Nbili, W.; Kaabi, K.; Ferretti, V.; Lefebvre, F.; Ben Nasr, C.

    2015-11-01

    Physico-chemical properties of a new organic indate(III) (C5H8N3O)2[InCl5(H2O)].H2O are discussed on the basis of its X-ray crystal structure investigation. The asymmetric unit includes two independent 2-amino-6-methylpyrimidinium-4-(1H)-one cations, one aquapentachloridoindate dianion, and one crystallization water molecule. The InIII ion is in a slightly distorted octahedral coordination geometry. In the crystal structure, the dimeric species formed by two metal complexes and two water molecules are connected to the 2-amino-6-methylpyrimidin-4-1H)-one cations through N-H⋯Cl hydrogen bonds to build 2D sheets parallel to the (b, a + c) plane. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed attributions of NMR signals and of the IR bands.

  15. Some practical notes on the land surface modeling in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    K. Yang

    2009-05-01

    Full Text Available The Tibetan Plateau is a key region of land-atmosphere interactions, as it provides an elevated heat source to the middle-troposphere. The Plateau surfaces are typically characterized by alpine meadows and grasslands in the central and eastern part while by alpine deserts in the western part. This study evaluates performance of three state-of-the-art land surface models (LSMs for the Plateau typical land surfaces. The LSMs of interest are SiB2 (the Simple Biosphere, CoLM (Common Land Model, and Noah. They are run at typical alpine meadow sites in the central Plateau and typical alpine desert sites in the western Plateau.

    The identified key processes and modeling issues are as follows. First, soil stratification is a typical phenomenon beneath the alpine meadows, with dense roots and soil organic matters within the topsoil, and it controls the profile of soil moisture in the central and eastern Plateau; all models, when using default parameters, significantly under-estimate the soil moisture within the topsoil. Second, a soil surface resistance controls the surface evaporation from the alpine deserts but it has not been reasonably modeled in LSMs; an advanced scheme for soil water flow is implemented in a LSM, based on which the soil resistance is determined from soil water content and meteorological conditions. Third, an excess resistance controls sensible heat fluxes from dry bare-soil or sparsely vegetated surfaces, and all LSMs significantly under-predict the ground-air temperature gradient, which would result in higher net radiation, lower soil heat fluxes and thus higher sensible heat fluxes in the models. A parameterization scheme for this resistance has been shown to be effective to remove these biases.

  16. Exhumation history of the southern Altiplano plateau (southern Bolivia) constrained by apatite fission track thermochronology

    Science.gov (United States)

    Ege, H.; Sobel, E. R.; Scheuber, E.; Jacobshagen, V.

    2007-02-01

    Although the structural geometry of the Cenozoic Altiplano-Puna plateau in the central Andes is well defined, the temporal evolution of this contractile deformation is poorly constrained. To address this shortcoming, we used apatite fission track thermochronology (AFT) to quantify the cooling and exhumation history along a transect at 21°S in southern Bolivia, through the deformed intermontane Altiplano basin, the doubly vergent thrust belt of the Eastern Cordillera and the inner foreland thrust belt east of the plateau (Interandean Zone). Thermal history modeling combined with published balanced cross sections and stratigraphic data constrain exhumation histories. Exhumation started during the late Eocene (40-36 Ma) in the central Eastern Cordillera, possibly due to bivergent thrusting and Cretaceous rift structure inversion. During the early Oligocene (33-27 Ma), exhumation spread across the study area as the current boundary thrusts of the Eastern Cordillera were activated. The inner west vergent thrust system became active in irregular order until circa 20 Ma, whereas the east vergent Interandean thrust belt formed by eastward propagating deformation since circa 30 Ma. Plateau exhumation continued at ˜0.2 mm/yr until shortening terminated by 11-7 Ma. Shortening within the plateau since circa 30 Ma did not evolve by lateral accretion of thrust wedges; the propagating deformation style is spatially confined to the foreland thrust belt, which initiated coeval to plateau deformation (Interandean Zone) but propagated mainly after circa 10 Ma (Subandean Zone). Early Oligocene plateau-wide tectonically driven exhumation suggests that subduction-related processes had already thermally weakened the continental lithosphere prior to the 27-25 Ma onset of volcanic activity.

  17. The crustal composition of the Falkland Plateau

    Science.gov (United States)

    Klemt, Claudia; Jokat, Wilfried

    2015-04-01

    The Falkland Islands are situated in the South Atlantic Ocean 500 km east of Patagonia, South America. The islands are part of the Falkland Plateau, which stretches eastward for more than 1500 km. A bathymetric high, the Maurice Ewing Bank, terminates the plateau in the east. Until Late Jurassic the Falkland Islands were part of Gondwana and were located adjacent to the east coast of South Africa. While the Falkland Islands and Maurice Ewing Bank are proved to be of continental composition, the nature and structure of the Falkland Plateau's basement in between is debatable. The first crustal model derived from sonobuoy data contradicts an only recently published 3D-gravity model. To enhance the understanding of Gondwana break-up considering timing, geometry and amount of volcanism, further knowledge about the structure and thickness of the crust is inevitable. During the ANT-XXIX/5 Polarstern cruise seismic refraction measurements were conducted using Ocean Bottom Seismometers (OBS) and Reftek land stations onshore of East Falkland. The OBS were deployed at 78 locations along an approximately 1500 km east-west stretching profile. For the western transect a P-wave velocity model is calculated using 2D-raytracing techniques. The results are presented in combination with potential field data showing the extension of the Falkland Islands basement, the continent-ocean transition zone and the crustal structure of the plateau. On the Falkland Plateau Basin sediment thickness is about 6 km with velocities ranging from 1.7 to 4.1 km/s in the upper part and about 4.7 km/s above basement. The crust is of oceanic composition with an igneous section that is considerably thicker than average oceanic crust (up to 17 km). The velocity structure in the upper crustal part is typical for layer 2 with a velocity gradient ranging from 5.4 km/s to 6.5 km/s and thicknesses between 1.5 km and 4 km. Layer 3 is about 14 km thick with a velocity gradient from 6.6 km/s to 7.6 km/s, which is

  18. The Influence of Low-frequency Oscillation Propagation of the Tibetan Plateau Vortex on Rainstorm Downstream

    Science.gov (United States)

    Xiao, Tiangui; Wang, Chao; La, Jia; Du, Jun; Zhang, Kairong

    2017-04-01

    Based on Tibetan Plateau vortex data, ERA-Interim and NCEP/NCAR reanalysis data, the characteristics of Tibetan Plateau vortex and the relationship with Low-Frequency Oscillation (LFO) from 2003 to 2012 were investigated. The heavy rainstorm occurred in Sichuan from June 29th to July 2nd in 2013, caused by the LFO, was studied. Besides, the signal of LFO, energy transmission and those influence to rainstorm were also investigate. The main conclusions are as follows: (1)Most of Tibetan Plateau vortex generate in eastern plateau, located at Tanggula Mountains, Zaduo, Dege, Qumalai and Qaidam. The moving-out Tibetan Plateau vortex mainly generate in Qumalai and most vortex occurrences during April to September. There are three directions of moving-out vortex paths: northeast, southeast and east. The areas which plateau vortex moving into are mainly distributed in Gansu, Sichuan, Shaanxi and Ningxia. (2)The zonal wind at 500hPa in plateau key region has a significant main 10-30d oscillation, with the secondly significant oscillation in 30-50d and the third in 70-90d. The relative vorticity at 500hPa in plateau key region has a significant main 30-50d oscillations, with the secondly significant oscillation in 10-30d. The 30-50d oscillation phase zone with weak westerly oscillation zone of 500hPa, and the 10-30d oscillation positive phase zone with weak oscillation zone of 500hPa are benefit to vortex generation. The 30-50d oscillation of zonal wind at 500hPa provides necessary circulation background for generation of plateau vortex, and positive phase region of 10-30d oscillation of relative vorticity at 500hPa provide necessary dynamic background conditions for it. (3) Comparing with the high frequency oscillation vortex, 10-25d low-frequency vortex is not significant at 500hPa before merging into the basin vortex. However, after merging into the basin vortex, there is a significant relationship between low-frequency vortex and the process of development, weakening and

  19. Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by zirconium (IV) chloride as a mild and efficient catalyst

    Institute of Scientific and Technical Information of China (English)

    Mohammad Abdollahi-Alibeik; Elahe Shabani

    2011-01-01

    2,3-Dihydroquinazolin-4(1H)-ones have been synthesized in the high to excellent yields via condensation of 2-aminobenzamide with aldehydes and ketones in the presence of catalytic amount of ZrCl4 in EtOH at room temperature. Mild reaction conditions, clean reaction media, simple workup and easy purification are advantages of this methodology.

  20. Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids

    Science.gov (United States)

    Dzhons, Daria Yu

    2016-01-01

    Summary The base-mediated photochemical cyclization of 2-azidobenzoic acids with the formation of 2,1-benzisoxazole-3(1H)-ones is reported. The optimization and scope of this cyclization reaction is discussed. It is shown that an essential step of the ring closure of 2-azidobenzoic acids is the formation and photolysis of 2-azidobenzoate anions. PMID:27340478

  1. Strontium chloride-catalyzed one-pot synthesis of 2, 3-dihydroquinazolin-4(1H)-ones in protic media

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Ting Ting Zhang; Yan Liang; Jing Jing Gao

    2011-01-01

    A wide range of mono- and disubstituted 2, 3-dihydroquinazolin-4(1H)-ones were obtained in high yields by condensation of isatoic anhydride, aldehydes with ammonium salts or primary amines in the presence of strontium chloride in aqueous ethanol under reflux.

  2. Green synthesis of tri/tetrasubstituted 1-imidazoles and 2,3-dihydroquinazolin-4(1H)-ones using nano aluminium nitride as solid source of ammonia

    Indian Academy of Sciences (India)

    Maryam Hajjami; Arash Ghorbani-Choghamarani; Zakieh Yousofvand; Masoomeh Rorouzi

    2015-07-01

    A simple, green and cost-effective protocol was achieved for the synthesis of tri/tetrasubstituted-1H-imidazoles and 2,3-dihydroquinazolin-4(1H)-ones using nano aluminium nitride. The reaction was carried out under catalyst-free conditions and the products were isolated in good to excellent yield.

  3. A Selective Synthesis of 2-Alkylamino-5, 6, 7, 8-tetrahydro benzothieno[2, 3-d]pyrimidin-4(3H)-ones

    Institute of Scientific and Technical Information of China (English)

    Ming Wu DING; Rui Jun XU; Jing XU; Yun Feng CHEN

    2005-01-01

    2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2, 3-d] pyrimidin-4(3H)-ones 7 were synthesized by a new selective synthetic method, which includes aza-Wittig reaction of iminophosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 with various aliphatic primary amine in the presence of EtO-Na+.

  4. Isomerization of 4-Amino-6-tert-butyl-3-methylthio-1, 2,4-triazin-5 (4H)-one with Base

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Isomerizaton of 4-amino-6-tert-butyl-3-methylthio-1, 2, 4-triazin-5 (4H)-one in the presence of base is described. Mechanism of this rearrangement reaction involving four-member ring intermediate formation has been proposed.

  5. Effects of honing treatment on AIP-TiN and TiAlN coated end-mill for high speed machining

    Institute of Scientific and Technical Information of China (English)

    Jae-Young HEO; Sung-Hak CHO; Tae-Jin JE; Kwang-Ho KIM; Hyung-Woo LEE; Myung-Chang KANG

    2011-01-01

    The objective of this work is to compare the tool performance of TiN and TiAIN coated carbides end-mills deposited by an arc ion plating (ALP) method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness (Ra) of 0.028 μm, the highest critical loads of TiN and TiAIN coating layers were 98 and 114 N. respectively. Tool performances of uncoated and coated tools were conducted under high speed machining (HSM) of AISI D2 cold-worked die steel (62 HRC). Consequently, the TiAIN coated end-mill using honing treatment showed excellent tool life under HSM conditions.

  6. Boehmite nanoparticle catalyst for the one-pot multicomponent synthesis of 3,4-dihydropyrimidin-2-(1H)-ones and thiones under solvent-free conditions

    Institute of Scientific and Technical Information of China (English)

    Ali Keivanloo; Mahdi Mirzaee; Mohammad Bakherad; Atena Soozani

    2014-01-01

    A simple, green, and efficient synthesis protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones using boehmite nanoparticles as catalyst was developed. It did not use any toxic metal cata-lysts or corrosive acidic reagents. The method gave good to excellent yields and has short reaction time, operational simplicity, and a recyclable catalyst.

  7. Silica-bonded N-propylsulfamic acid as a recyclable catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

    Institute of Scientific and Technical Information of China (English)

    Khodabakhsh Niknam; Nasrolah Jafarpour; Ebrahim Niknam

    2011-01-01

    2,3-Dihydroquinazolin-4(1H)-one derivatives are synthesized via a one-pot,three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-propylsulfamic acid(SBNPSA)in refluxing ethanol.

  8. Nuclear Magnetic Resonance (NMR), Infrared (IR) and Mass Spectrometry (MS) study of keto-enol tautomerism of isobenzofuran-1(3H)-one derivatives

    Science.gov (United States)

    Pires, Diego Arantes Teixeira; Pereira, Wagner Luiz; Teixeira, Róbson Ricardo; Figueroa-Villar, José Daniel; Nascimento, Claudia Jorge do

    2016-06-01

    The keto-enol tautomerism of 3-(2-hydroxy-4,4-dimethyl-6-oxo-cyclohexen-1-yl)isobenzofuran-1(3H-one (1), 3-(2-hydroxy-6-oxocyclohex-1-enyl)isobenzofuran-1(3H)-one (2), 3-(2-hydroxy-4-methyl-6-oxocyclohex-1-enyl)isobenzofuran-1(3H)-one (3), 3-(2-hydroxy-5-oxocyclopent-1-enyl)isobenzofuran-1(3H)-one (4) and 2-(3-oxo-1,3-dihydroisobenzofuran-1-yl)-1H-indene-1,3(2H)-dione (5) were investigated. We noticed that for compounds 1 to 4 only the enol form is observed in solid, in solution or in the gas phase. Their tautomeric equilibria are not affected by the solvent, temperature or physical state. Compound 5 was observed in its keto form in solution (NMR) and solid state (IR). The enol species of 5 was also observed upon Mass Spectrometry analysis. These findings were supported by NMR, IR, MS/MS and molecular modeling analyses.

  9. One-pot and Three-Component Synthesis of isoxazol-5(4H-one Derivatives in the presence of Citric Acid

    Directory of Open Access Journals (Sweden)

    Ashkan bashash Rikani

    2016-06-01

    Full Text Available In this context, the one-pot three-component synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H-ones has been performed in the presence of citric acid as catalyst in water. The products have been obtained in high yields (70-90% and convenient reaction times (5-24 hours.

  10. Synthesis of 2,1-benzisoxazole-3(1H-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids

    Directory of Open Access Journals (Sweden)

    Daria Yu. Dzhons

    2016-05-01

    Full Text Available The base-mediated photochemical cyclization of 2-azidobenzoic acids with the formation of 2,1-benzisoxazole-3(1H-ones is reported. The optimization and scope of this cyclization reaction is discussed. It is shown that an essential step of the ring closure of 2-azidobenzoic acids is the formation and photolysis of 2-azidobenzoate anions.

  11. Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N-O bond-forming cyclization of 2-azidobenzoic acids.

    Science.gov (United States)

    Dzhons, Daria Yu; Budruev, Andrei V

    2016-01-01

    The base-mediated photochemical cyclization of 2-azidobenzoic acids with the formation of 2,1-benzisoxazole-3(1H)-ones is reported. The optimization and scope of this cyclization reaction is discussed. It is shown that an essential step of the ring closure of 2-azidobenzoic acids is the formation and photolysis of 2-azidobenzoate anions.

  12. H-Y-zeolites induced heterocyclization: Highly efficient synthesis of substituted-quinazolin-4(3H)ones under microwave irradiation

    Institute of Scientific and Technical Information of China (English)

    M. Bakavoli; O. Sabzevari; M. Rahimizadeh

    2007-01-01

    A highly efficient synthesis of 2-amino-N-substituted-benzamides was performed by the condensation of isatoic anhydride with several amines in solvent-free conditions under microwave irradiation. H-Y-zeolites induced heterocyclization of these products with ortho-esters under similar conditions afforded the relevant substituted-quinazolin-4(3H)ones in high yields.

  13. Synthesis of 2-Alkyl(aryl)-3-methylthio-6-methyl-6-arylpyrano-[4, 3-c] pyrazol-4(2H)-ones

    Institute of Scientific and Technical Information of China (English)

    Yu Xin LI; You Ming WANG; Xiao Ping YANG; Su Hua WANG; Zheng Ming LI

    2004-01-01

    The synthesis of 2-alkyl(aryl)-3-methylthiopyrano[4,3-c]pyrazol-4(2H)-ones via 5, 6-dihydro-2H-pyran-2, 4-dione-3-dithioacetals with (un)substituted hydrazines is described and the mechanism of the formation of title compounds is discussed. Their structures were confirmed by 1HNMR spectra and elemental analysis.

  14. Interannual Variability of the Normalized Difference Vegetation Index on the Tibetan Plateau and Its Relationship with Climate Change

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dingwen; FAN Guangzhou; HUANG Ronghui; FANG Zhifang; LIU Yaqin; LI Hongquan

    2007-01-01

    The Qinghai-Xizang Plateau, or Tibetan Plateau, is a sensitive region for climate change, where the manifestation of global warming is particularly noticeable. The wide climate variability in this region significantly affects the local land ecosystem and could consequently lead to notable vegetation changes. In this paper, the interannual variations of the plateau vegetation are investigated using a 21-year normalized difference vegetation index (NDVI) dataset to quantify the consequences of climate warming for the regional ecosystem and its interactions. The results show that vegetation coverage is best in the eastern and southern plateau regions and deteriorates toward the west and north. On the whole, vegetation activity demonstrates a gradual enhancement in an oscillatory manner during 1982-2002. The temporal variation also exhibits striking regional differences: an increasing trend is most apparent in the west, south, north and southeast, whereas a decreasing trend is present along the southern plateau boundary and in the central-east region. Covariance analysis between the NDVI and surface temperature/precipitation suggests that vegetation change is closely related to climate change. However, the controlling physical processes vary geographically. In the west and east, vegetation variability is found to be driven predominantly by temperature, with the impact of precipitation being of secondary importance. In the central plateau, however, temperature and precipitation factors are equally important in modulating the interannual vegetation variability.

  15. Relationship Between the Eastern Tibetan Plateau Rainfall and Subtropical High Shift in Summer

    Institute of Scientific and Technical Information of China (English)

    GONG Yuanfa; HE Jinhai; CHEN Longxun

    2006-01-01

    Based on the routine rainfall data on the Tibetan Plateau and NCEP/NCAR reanalysis data, the rela tionship between the eastern Tibetan Plateau rainfall and the southward/northward shift of West Pacific subtropical high in summer of 1993/1994 is studied. The results show that: the West Pacific subtropi cal high is abnormally located to more southern latitude and the high ridge is mainly the quasi-biweekly southward/northward oscillation in its processes of northward shift from May to August in 1993; but it is ab normally located to more northern latitude and the high ridge is obviously 30-60-day southward/northward oscillation in its processes of northward shift from May to August in 1994. At the same time, it is found that the changes of the eastern Tibetan Plateau rainfall active/break have the similar characteristics of the high ridge southward/northward oscillation. Therefore, the southward/northward shift of the West Pacific subtropical high in summer may be related to the changes of eastern Tibetan Plateau rainfall active/break.

  16. Spatial distribution and controlling factors of stable isotopes in meteoric waters on the Tibetan Plateau: Implications for paleoelevation reconstruction

    Science.gov (United States)

    Li, Lin; Garzione, Carmala N.

    2017-02-01

    Debates persist about the interpretations of stable isotope based proxies for the surface uplift of the central-northern Tibetan Plateau. These disputes arise from the uncertain relationship between elevation and the δ18 O values of meteoric waters, based on modern patterns of isotopes in precipitation and surface waters. We present a large river water data set (1,340 samples) covering most parts of the Tibetan Plateau to characterize the spatial variability and controlling factors of their isotopic compositions. Compared with the amount-weighted mean annual oxygen isotopic values of precipitation, we conclude that river water is a good substitute for isotopic studies of precipitation in the high flat (e.g., elevation >3,300 m) interior of the Tibetan Plateau in the mean annual timescale. We construct, for the first time based on field data, contour maps of isotopic variations of meteoric waters (δ18 O, δD and d-excess) on the Tibetan Plateau. In the marginal mountainous regions of the Plateau, especially the southern through eastern margins, the δ18 O and δD values of river waters decrease with increasing mean catchment elevation, which can be modeled as a Rayleigh distillation process. However, in the interior of the Plateau, northward increasing trends in δ18 O and δD values are pronounced and present robust linear relations; d-excess values are lower than the marginal regions and exhibit distinct contrasts between the eastern (8 ‰- 12 ‰) and western (<8‰) Plateau. We suggest that these isotopic features of river waters in the interior of the Tibetan Plateau result from the combined effects of: 1) mixing of different moisture sources transported by the South Asian monsoon and Westerly winds; 2) contribution of moisture from recycled surface water; and 3) sub-cloud evaporation. We further provide a sub-cloud evaporation modified Rayleigh distillation and mixing model to simulate the isotopic variations in the western Plateau. Results of this work

  17. Livelihood Vulnerability Assessment Of Farmers and Nomads in Eastern Ecotone of Tibetan Plateau

    Science.gov (United States)

    Yan, J.; Zhang, Y.

    2011-12-01

    Livelihood vulnerability assessment provides a scientific basis for anti-poverty of people and regional sustainable development in vulnerable area. Although there are massive discussions on concept of vulnerability, it is still difficult to make it quantitative and to carry out comprehensive appraise. Vulnerability assessments based on sustainable livelihood frame are widely accepted in case studies for attentions to vulnerable groups. However, these case studies are always on regional scale and never reflect how climate change affects people's livelihood and adaptive capability of people. It is necessary to seek vulnerable assessment index system and means based on livelihood process of local people. This paper develops a livelihood vulnerability assessment index system on the basis of sustainable livelihood framework and appraises livelihood vulnerability values of 11 townships, using data of 879 sample households. Livelihood vulnerability assessment index system reflects main risks, livelihood assets and adaptation strategies of local people and government. The results show that livelihood vulnerability level of plateau region is higher than that of mountain to plateau region and mountain gorge region. Manzhang Township in plateau region is the most vulnerable township and nomads there cannot cope with risks of climate change, meadow degeneration and herbs degradation. Upper part of mountain to plateau region and the whole plateau region have high livelihood vulnerability values and local nomads would not cope with risks if no measures are taken by government. The driving forces of livelihood vulnerability include strikes of risks and deficiency of livelihood assets and adaptive capability. Farmers and nomads in high mountain gorge region and lower part of mountain to plateau region can cope with these risks, meanwhile, there are more employment opportunities in second and tertiary industries are needed to help them realize livelihood diversification. Therefore

  18. Chemical erosion and hydrologic budget for the Susure karst plateau

    Directory of Open Access Journals (Sweden)

    Nikić Zoran

    2010-01-01

    Full Text Available The karst plateau of Susure, about 4.5 km2 in surface area, is situated on the Jadovnik eastern offset, western Serbia. The plateau is a morphologic unit higher 15 m to 30 m than the surrounding terrain. The unit consists of crushed and karstified Middle Triassic limestones. Numerous hydrogeological and geomorphologic features of the plateau are attractive for visitors in this economically underdeveloped country. Rocks building up the surrounding terrain are largely peridotites. Surface streams flow neither into nor off the plateau. Atmospheric precipitations discharge to evapotanspiration and filtration underground. More than eighteen constant springs at the limestone/peridotite tectonic contact drain fracture aquifers on the karst plateau border. Measured precipitations and springflows were the input and output data for accounting water budget of an aquifer of Middle Triassic limestones in the Susure plateau.

  19. Melt-Enhanced Rejuvenation of Lithospheric Mantle: Insights from the Colorado Plateau

    CERN Document Server

    Roy, Mousumi; Holtzman, Ben; Gaherty, James

    2012-01-01

    The stability of the lithospheric mantle beneath the ancient cratonic cores of continents is primarily a function of chemical modification during the process of melt extraction. Processes by which stable continental lithosphere may be destabilized are not well-understood, although destabilization by thickening and removal of negatively-buoyant lithospheric mantle in "delamination" events has been proposed in a number of tectonic settings. In this paper we explore an alternative process for destabilizing continents, namely, thermal and chemical modification during infiltration of metasomatic fluids and melts into the lithospheric column. We consider observations pertinent to the structure and evolution of the Colorado Plateau within the western United States to argue that the physical and chemical state of the margins of the plateau have been variably modified and destabilized by interaction with melts. In the melt-infiltration process explored here, the primary mechanism for weakening and rejuvenating the pla...

  20. A study of cloud microphysics and precipitation over the Tibetan Plateau by radar observations and cloud-resolving model simulations: Cloud Microphysics over Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wenhua [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China; Pacific Northwest National Laboratory, Richland Washington USA; Sui, Chung-Hsiung [Department of Atmospheric Sciences, National Taiwan University, Taipei Taiwan; Fan, Jiwen [Pacific Northwest National Laboratory, Richland Washington USA; Hu, Zhiqun [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China; Zhong, Lingzhi [State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing China

    2016-11-27

    Cloud microphysical properties and precipitation over the Tibetan Plateau (TP) are unique because of the high terrains, clean atmosphere, and sufficient water vapor. With dual-polarization precipitation radar and cloud radar measurements during the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX-III), the simulated microphysics and precipitation by the Weather Research and Forecasting model (WRF) with the Chinese Academy of Meteorological Sciences (CAMS) microphysics and other microphysical schemes are investigated through a typical plateau rainfall event on 22 July 2014. Results show that the WRF-CAMS simulation reasonably reproduces the spatial distribution of 24-h accumulated precipitation, but has limitations in simulating time evolution of precipitation rates. The model-calculated polarimetric radar variables have biases as well, suggesting bias in modeled hydrometeor types. The raindrop sizes in convective region are larger than those in stratiform region indicated by the small intercept of raindrop size distribution in the former. The sensitivity experiments show that precipitation processes are sensitive to the changes of warm rain processes in condensation and nucleated droplet size (but less sensitive to evaporation process). Increasing droplet condensation produces the best area-averaged rain rate during weak convection period compared with the observation, suggesting a considerable bias in thermodynamics in the baseline simulation. Increasing the initial cloud droplet size causes the rain rate reduced by half, an opposite effect to that of increasing droplet condensation.

  1. Colorado Plateau magmatism and uplift by warming of heterogeneous lithosphere.

    Science.gov (United States)

    Roy, Mousumi; Jordan, Thomas H; Pederson, Joel

    2009-06-18

    The forces that drove rock uplift of the low-relief, high-elevation, tectonically stable Colorado Plateau are the subject of long-standing debate. While the adjacent Basin and Range province and Rio Grande rift province underwent Cenozoic shortening followed by extension, the plateau experienced approximately 2 km of rock uplift without significant internal deformation. Here we propose that warming of the thicker, more iron-depleted Colorado Plateau lithosphere over 35-40 Myr following mid-Cenozoic removal of the Farallon plate from beneath North America is the primary mechanism driving rock uplift. In our model, conductive re-equilibration not only explains the rock uplift of the plateau, but also provides a robust geodynamic interpretation of observed contrasts between the Colorado Plateau margins and the plateau interior. In particular, the model matches the encroachment of Cenozoic magmatism from the margins towards the plateau interior at rates of 3-6 km Myr(-1) and is consistent with lower seismic velocities and more negative Bouguer gravity at the margins than in the plateau interior. We suggest that warming of heterogeneous lithosphere is a powerful mechanism for driving epeirogenic rock uplift of the Colorado Plateau and may be of general importance in plate-interior settings.

  2. Sapping Features of the Colorado Plateau: a Comparative Planetary Geology Field Guide

    Science.gov (United States)

    Howard, Alan D. (Editor); Kochel, R. Craig (Editor); Holt, Henry E. (Editor)

    1987-01-01

    This book is an attempt to determine geomorphic criteria to be used to distinguish between channels formed predominantly by sapping and seepage erosion and those formed principally by surface runoff processes. The geologic nature of the Colorado Plateau has resulted in geomorphic features that show similarities to some areas on Mars, especially certain valley networks within thick sandstone formations. Where spring sapping is an effective process, the valleys that develop are unique in terms of their morphology and network pattern.

  3. Experimental and theoretical studies of the influence of solvent polarity on the spectral properties of two push-pull oxazol-5-(4H)-one compounds.

    Science.gov (United States)

    Jędrzejewska, Beata; Krawczyk, Przemysław; Józefowicz, Marek

    2017-01-15

    Spectral and photophysical properties of two derivatives of the 2-phenyl-1,3-oxazol-5(4H)-ones were studied in 17 solvents of different polarity. These compounds have either push-pull non-centrosymmetric or C3-symmetric structures with electron-withdrawing groups (2-phenyl-oxazolone) introduced onto the triphenylamine. It has been found that their spectral and photophysical properties depend on the structure of the compounds and on the solvent polarity. The non-radiative relaxation process is facilitated by an increase of the solvent polarity. The changes in the electronic absorption and fluorescence maximum positions with solvent polarity were analyzed applying different solvent polarity parameters based on Lippert-Mataga, McRae, Bakhshiev and Kawski theories or ET(N) scale. The long-wavelength absorption band positions exhibit a slight dependence on the solvent, whereas the fluorescence spectra demonstrate substantial positive solvatochromism. It was found that the position of the electronic absorption band depends mainly on the solute polarizability (related to the solvent refraction index function f(n(2))=(n(2)-1)/(2n(2)+1)), whereas the solvent polarity influences the position of the fluorescence band. Quantum chemical calculations of the transition energies and dipole moments at the DFT level have been also performed. The difference between the first excited and ground state dipole moments was found experimentally to be 10.8 D and 13.0 D according to Bakhshiev's model. The experimental values of Δμ were compared to that one obtained from theoretical calculations for various solvents.

  4. Experimental and theoretical studies of the influence of solvent polarity on the spectral properties of two push-pull oxazol-5-(4H)-one compounds

    Science.gov (United States)

    Jędrzejewska, Beata; Krawczyk, Przemysław; Józefowicz, Marek

    2017-01-01

    Spectral and photophysical properties of two derivatives of the 2-phenyl-1,3-oxazol-5(4H)-ones were studied in 17 solvents of different polarity. These compounds have either push-pull non-centrosymmetric or C3-symmetric structures with electron-withdrawing groups (2-phenyl-oxazolone) introduced onto the triphenylamine. It has been found that their spectral and photophysical properties depend on the structure of the compounds and on the solvent polarity. The non-radiative relaxation process is facilitated by an increase of the solvent polarity. The changes in the electronic absorption and fluorescence maximum positions with solvent polarity were analyzed applying different solvent polarity parameters based on Lippert-Mataga, McRae, Bakhshiev and Kawski theories or ETN scale. The long-wavelength absorption band positions exhibit a slight dependence on the solvent, whereas the fluorescence spectra demonstrate substantial positive solvatochromism. It was found that the position of the electronic absorption band depends mainly on the solute polarizability (related to the solvent refraction index function f(n2) = (n2-1) / (2n2 + 1)), whereas the solvent polarity influences the position of the fluorescence band. Quantum chemical calculations of the transition energies and dipole moments at the DFT level have been also performed. The difference between the first excited and ground state dipole moments was found experimentally to be 10.8 D and 13.0 D according to Bakhshiev's model. The experimental values of Δμ were compared to that one obtained from theoretical calculations for various solvents.

  5. Observational Facts of Sustained Departure Plateau Vortexes

    Institute of Scientific and Technical Information of China (English)

    YU Shuhua; GAO Wenliang; PENG Jun; XIAO Yuhua

    2014-01-01

    By using the twice-daily atmospheric observation data from 1998 to 2012, station rainfall data, Tropical Rainfall Measure Mission (TRMM) data, as well as the plateau vortex and shear line year book, charac-teristics of the sustained departure plateau vortexes (SDPVs) are analyzed. Some new useful observational facts and understanding are obtained about the SDPV activities. The following results are obtained. (1) The active period of SDPVs is from June to August, most in July, unlike that of the unsustained depar-ture plateau vortexes (UDPVs), which have same occurrence frequencies in the three summer months. (2) The SDPVs, generated mainly in the Qumalai neighborhood and situated in a sheared surrounding, move eastward or northeastward, while the UDPVs are mainly led by the upper-level trough, and move eastward or southeastward. (3) The SDPVs influence wide areas of China, even far to the Korean Peninsula, Japan, and Vietnam. (4) The SDPVs change their intensities and properties on the way to the east. Most of them become stronger and produce downpour or sustained regional rainstorms to the south of Yellow River. (5) The longer the SDPV sustains, the more baroclinity it has. (6) When an SDPV moves into the sea, its central pressure descends and rainfall increases in all probability. (7) An SDPV might spin over the bend of the Yellow River when there exists a tropical cyclone in the East China Sea. It could also move oppositely to a landed tropical low pressure originated from the sea to the east of Taiwan or from the South China Sea.

  6. Contrast Enhancement Using Brightness Preserving Histogram Plateau Limit Technique

    Directory of Open Access Journals (Sweden)

    K. Santhi

    2014-07-01

    Full Text Available Contrast enhancement is an important factor in the gray scale images. One of the widely accepted contrast enhancement method is the Histogram equalization (HE. HE achieves comparatively better performance on almost all types of image but sometimes produces excessive visual deterioration. The proposed Contrast Enhancement using Brightness Preserving Histogram Plateau Limit (CEBPHPL method provides better brightness preservation without allowing in excess of contrast improvement measure. This method decomposes the input image by computing the local maxima of the smoothed image using Gaussian filter which reduces the noise. Then the clipping process has been implemented which provides the good enhancement rate than the conventional methods. The experimental result of the proposed CEBPHPL is better than the existing methods.

  7. Relation between stable isotope in monsoon precipitation in southern Tibetan Plateau and moisture transport history

    Institute of Scientific and Technical Information of China (English)

    田立德; 姚檀栋; A.Numaguti; 段克勤

    2001-01-01

    The moisture transport history to the south of the Tibetan Plateau was modeled using the meteorological data provided by NCEP in this paper, and the modeled results were compared with the measured δ18O in the south of the Tibetan Plateau. The relation between δ18O in precipitation in the south of the Tibetan Plateau and moisture trajectories was discussed. The results show that the extremely low δ18O in precipitation in the south of the Tibetan Plateau is always related to the moisture from the low-level sea surface evaporation. The long-distance transport of moisture also contributes to low δ18O in precipitation probably due to the rainout process during moisture transport. It is also found that lowδ18O in precipitation is also related with deep layer transport of moisture, and with intensive condensation in the upper layers of the atmosphere, resulting in low δ18O because of depletion of heavy isotopes in deep condensation. However, high δ18O in precipitation whether in monsoon period or not is

  8. Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    孙东怀; 刘东生; 陈明扬; 安芷生; John Shaw

    1997-01-01

    Two Red Clay profiles near Xi’ an and Xifeng were investigated in an attempt to determine magne-tostratigraphic and palaeoclimatic records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma, and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5-2.5 Ma. Stepwise increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan Plateau, sola

  9. Mio-Pliocene morphotectonic evolution of the Iranian Plateau: from outward expansion to incision and excavation

    Science.gov (United States)

    Ballato, Paolo; Heidarzadeh, Ghasem; Zeilinger, Gerold; Ghassemi, Mohammad; Cifelli, Francesca; Mattei, Massimo; Hassanzadeh, Jamshid; Balling, Philipp; Dunkl, István; Sudo, Masafumi; Mulch, Andreas; Strecker, Manfred

    2015-04-01

    Located along plate convergence zones, high orogenic plateaus form extensive and elevated morphotectonic provinces that are flanked by high mountain ranges at their margins. The Iranian Plateau (IP) is a prominent NW-SE striking (ca. 1500 km in length for a width of 140 to 260 km), elevated (> 50% lies between 1.5 and 2 km of elevation), mostly internally drained (at present ca. 55% has internal drainage), arid (mean annual precipitation ranging from 0.1 to 50 km of distance) of conglomerates in the distal sectors of the basin. This event was followed by basin uplift and erosion with a shift of the basin depocenter toward the outer margin of the plateau (to the N and NE; Zanjan and Mianeh basins). There, sedimentation lasted until fluvial incision and basin excavation of sub-horizontal sediments started sometime during the last 4 Ma. Overall, our data suggest that sedimentation took place in a contiguous foreland-basin system, most likely triggered by thrust stacking and topographic loading in the interior of the plateau from ~17 Ma. The outward N to NE-directed propagation of the deformation fronts (< 10.5 Ma) excised parts of the foreland, incorporating new basin sectors into the orogenic plateau and compartmentalizing the foreland into a contractional basin and range topography. This implies that the IP developed during crustal shortening and thickening processes and that sometime after 10.5 Ma the northern IP had reached a lateral size similar to the modern one.

  10. [Coupling coordinated development of ecological-economic system in Loess Plateau].

    Science.gov (United States)

    Zhang, Qing-Feng; Wu, Fa-Qi; Wang, Li; Wang, Jian

    2011-06-01

    Based on system theory, a coupling coordinated development model of ecological-economic system in Loess Plateau was established, and the evaluation criteria and basic types of the coordinated development of the ecological-economic system were proposed. The county-level coupling coordinated development of the ecological-economic system was also discussed, based on the local characteristics. The interactions between the ecological and economic systems in Loess Plateau could be divided into four stages, i.e., seriously disordered development stage, mild-disordered development stage, low-level coordinated development stage, and high level well-coordinated development stage. At each stage, there existed a cyclic process of profit and loss-antagonist-running-dominant-synchronous development. The coupling development degree of the ecological-economic system in Loess Plateau was overall at a lower level, being about 62.7% of the counties at serious disorder, 30.1% of the counties at mild disorder, and 7.1% of the counties at low but coordinated level. The coupling development degree based on the model established in this study could better reflect the current social-economic and ecological environment situations, especially the status of coordination. To fully understand the coupling of ecological-economic system and to adopt appropriate development mode would be of significance to promote the county-level coordinated development in Loess Plateau.

  11. Tracing grassland degradation on the Eastern Tibetan Plateau with multi-temporal remote sensing data

    Science.gov (United States)

    Fassnacht, Fabian E.; Li, Li; Fritz, Andreas

    2017-04-01

    The Tibetan Plateau in Western China is the world's largest alpine landscape, sheltering a rich diversity of native flora and fauna. In the past few decades, the Tibetan Plateau was found to suffer from grassland degradation processes. Grassland degradation is assumed to not only endanger biodiversity but also to increase the risk for natural hazards in other parts of the country which are ecologically and hydrologically connected to the area. Grassland degradation is furthermore, changing the albedo of the surfaces of the Plateau and may therefore even notably affect atmospheric and climatic processes. However, the mechanisms behind the degradation processes remain poorly understood due to scarce baseline data and insufficient scientific research as well as manifold potential influences on the degradation processes including pastoral management, climate, herbivor mammals and administrative decisions. This study tries to contribute to this research gap by tracing grassland degradation processes by time-series analysis of multi-spectral Landsat data. After identifying the degraded areas, it is examined whether the degradation patterns relate to topographic properties, climatic gradients or administrative borders. Results from a first study showed that most degradation occurred in high-altitude areas, while slope and aspect where not having a notable influence. Furthermore, a climatic gradient within the study area was found to correlate with the degradation patterns observed for large extents. Currently, the study is being expanded over a larger area and more detailed spatially-adaptive analysis concerning the degradation drivers are being developed. Corresponding results will be presented. We conclude that remotely sensed patterns of grassland degradation can contribute to an improved understanding of the degradation processed on the Tibetan Plateau by providing spatially and temporally explicit information on the degradation processes at an adequate scale.

  12. Synthesis of new N-benzoxazole and N-benzothiazole derivatives of 3-(4-substituted phenyl) aminoisoxazol-5(2H)-ones and comparison of their base induced rearrangement

    Energy Technology Data Exchange (ETDEWEB)

    Khalafy, Jabbar; Marjani, Ahmad Poursattar; Ebrahimlo, Ali Reza Molla [Urmia University, Urmia (Iran, Islamic Republic of). Dept. of Chemistry]. E-mail: jkhalafi@yahoo.com

    2006-05-15

    3-Arylaminoisoxazol-5(2H)-ones, substituted on nitrogen with benzoxazole and benzothiazole groups react with triethylamine in ethanol under reflux to afford the corresponding indole and imidazobenzothiazole derivatives, respectively. (author)

  13. 3-(4-Bromophenyl-4-[2-(4-nitrophenylhydrazinyl]furan-2(5H-one

    Directory of Open Access Journals (Sweden)

    Zhu-Ping Xiao

    2011-11-01

    Full Text Available In the title compound, C16H12BrN3O4, the furan-2(5H-one ring forms a dihedral angle of 33.19 (9° with the 4-bromobenzene unit and is nearly perpendicular to the 4-nitrobenzene segment, making a dihedral angle of 89.93 (10°. In the crystal, N—H...O hydrogen bonds link the molecules, generating an infinite chain along [010]. The chains are linked into a three-dimensional network by C—H...O, C—H...π and π–π contacts [centroid–centroid separation = 3.805 (2 Å].

  14. Water and ionic liquid synergy: A novel approach for the synthesis of benzothiazole-2(3H-one

    Directory of Open Access Journals (Sweden)

    Malik A. Waseem

    2015-05-01

    Full Text Available Synergy between water, a green reaction medium and ionic liquid, a green catalyst has opened new vistas in the field of organic transformation. The developed methodology has emerged as an interesting combination for an environmentally benign, facile and efficient synthesis of benzothiazole-2(3H-one. Product was achieved in excellent yield by the reaction of structurally diverse 2-iodoanilines with potassium thiocyanate. The strategy involves nucleophilic substitution forming NC and SC bonds resulting in the desired heterocyclic scaffold. This novel approach is also helpful for the synthesis of other related heterocycles for the development of an important drug like library. The reaction proceeded smoothly at an ambient temperature.

  15. Discovery of antibiotic (E)-3-(3-carboxyphenyl)-2-(4-cyanostyryl)quinazolin-4(3H)-one.

    Science.gov (United States)

    Bouley, Renee; Kumarasiri, Malika; Peng, Zhihong; Otero, Lisandro H; Song, Wei; Suckow, Mark A; Schroeder, Valerie A; Wolter, William R; Lastochkin, Elena; Antunes, Nuno T; Pi, Hualiang; Vakulenko, Sergei; Hermoso, Juan A; Chang, Mayland; Mobashery, Shahriar

    2015-02-11

    In the face of the clinical challenge posed by resistant bacteria, the present needs for novel classes of antibiotics are genuine. In silico docking and screening, followed by chemical synthesis of a library of quinazolinones, led to the discovery of (E)-3-(3-carboxyphenyl)-2-(4-cyanostyryl)quinazolin-4(3H)-one (compound 2) as an antibiotic effective in vivo against methicillin-resistant Staphylococcus aureus (MRSA). This antibiotic impairs cell-wall biosynthesis as documented by functional assays, showing binding of 2 to penicillin-binding protein (PBP) 2a. We document that the antibiotic also inhibits PBP1 of S. aureus, indicating a broad targeting of structurally similar PBPs by this antibiotic. This class of antibiotics holds promise in fighting MRSA infections.

  16. PowerPoint Presentations: A Creative Addition to the Research Process.

    Science.gov (United States)

    Perry, Alan E.

    2003-01-01

    Contends that the requirement of a PowerPoint presentation as part of the research process would benefit students in the following ways: learning how to conduct research; starting their research project sooner; honing presentation and public speaking skills; improving cooperative and social skills; and enhancing technology skills. Outlines the…

  17. PowerPoint Presentations: A Creative Addition to the Research Process.

    Science.gov (United States)

    Perry, Alan E.

    2003-01-01

    Contends that the requirement of a PowerPoint presentation as part of the research process would benefit students in the following ways: learning how to conduct research; starting their research project sooner; honing presentation and public speaking skills; improving cooperative and social skills; and enhancing technology skills. Outlines the…

  18. The Manihiki Plateau, Hikurangi Plateau, Wishbone Scarp, and Osbourn Trough: A Review and Analysis

    Science.gov (United States)

    Henig, A.; Luyendyk, B. P.

    2007-12-01

    The extinct Osbourn Trough spreading system in the southwestern Pacific played a key role in separating the once joined Hikurangi and Manihiki Plateaus in Cretaceous time. Recent studies by Downey et al. [2007] and Taylor [20006] have provided new data and concepts on that history. Studies by Larson et al. [2002] describe Cretaceous histories adjacent and east of the Osbourn system and Eagles et al. [2004] describe a history for the southwest Pacific just after the Osbourn system became extinct. The lack of identifiable magnetic anomalies allows tectonic events during separation of the plateaus and spreading on the Osbourn Trough to occur between about 124.6 and 84 Ma (Chron 34). Satellite gravity maps of the region identify what are interpreted as Cretaceous fracture zone trends. Swath bathymetry data reveal at least four provinces of abyssal hill trends. What is known are the following: Minimum age of the Manihiki High Plateau at 123.4 Ma from DSDP Site 317, the age of seafloor, 115 Ma, from a dredge sample from the southern segment of the West Wishbone Scarp 300 km northeast of the Hikurangi Plateau, the east-west trend and extent of the extinct Osbourn spreading center at latitude 26° S, the trends (NNE-SSW to NE-SW) and extent of portions of the West Wishbone Scarp east of the Hikurangi Plateau, the N-S trend of the East Wishbone Scarp that appears to truncate the West Wishbone Scarp, the NNE- SSW trend and extent of the prominent Manihiki (Eastern) Scarp at the eastern boundary of the Manihiki High Plateau, the NW-SE trend and extent of the Rapuhia Scarp on the northwestern Hikurangi Plateau, and trends in abyssal hills; E-W near the Osbourn Trough and WNW-ESE closer to the plateaus. Differences in abyssal hill morphology suggest one or more changes in spreading rates. The Osbourn Trough began rifting apart a Large Igneous Province formed at 123.5 +/- 1.5 Ma, into the separate Ontong-Java, Manihiki, and Hikurangi Plateaus by 121 Ma. After an initial 6 Myr

  19. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

    Science.gov (United States)

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek

    2016-01-01

    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  20. Interpretation of Plateau in High-Harmonic Generation

    Institute of Scientific and Technical Information of China (English)

    程太旺; 李晓峰; 敖淑艳; 傅盘铭

    2003-01-01

    The plateau in high-harmonic generation is investigated in the frequency domain. Probability density of an electron in an electromagnetic field is obtained through analysing the quantized-field Volkov state. The plateau of high-harmonic generation reflects the spectral density of the electron at the location of nucleus after abovethreshold ionization.

  1. Ongoing speciation in the Tibetan plateau Gymnocypris species complex.

    Science.gov (United States)

    Zhang, Renyi; Peng, Zuogang; Li, Guogang; Zhang, Cunfang; Tang, Yongtao; Gan, Xiaoni; He, Shunping; Zhao, Kai

    2013-01-01

    Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke) in the Northeast Tibetan Plateau. We used a combination of mitochondrial (16S rRNA and Cyt b) and nuclear (RAG-2) genetic sequences to investigate the phylogeography of these morphs based on a sample of 277 specimens. Analysis of gill rakers allowed for mapping of phenotypic trajectories along the phylogeny. The phylogenetic and morphological analyses showed that the three sparsely rakered morphs were present at two extremes of the phylogenetic tree: the Yellow River morphs were located at the basal phylogenetic split, and the Lake Keluke and Ganzi River morphs at the peak, with the densely rakered Lake Qinghai morphs located between these two extremes. Age estimation further indicated that the sparsely rakered morphs constituted the oldest and youngest lineages, whereas the densely rakered morph was assigned to an intermediate-age lineage. These results are most compatible with the process of evolutionary convergence or reversal. Disruptive natural selection due to divergent habitats and dietary preferences is likely the driving force behind the formation of new morphs, and the similarities between their phenotypes may be attributable to the similarities between their forms of niche tracking associated with food acquisition. This study provides the first genetic evidence for the occurrence of convergence or reversal in the schizothoracine fish of the Tibetan Plateau at small temporal scales.

  2. Ongoing speciation in the Tibetan plateau Gymnocypris species complex.

    Directory of Open Access Journals (Sweden)

    Renyi Zhang

    Full Text Available Local adaptation towards divergent ecological conditions often results in genetic differentiation and adaptive phenotypic divergence. To illuminate the ecological distinctiveness of the schizothoracine fish, we studied a Gymnocypris species complex consisting of three morphs distributed across four bodies of water (the Yellow River, Lake Qinghai, the Ganzi River and Lake Keluke in the Northeast Tibetan Plateau. We used a combination of mitochondrial (16S rRNA and Cyt b and nuclear (RAG-2 genetic sequences to investigate the phylogeography of these morphs based on a sample of 277 specimens. Analysis of gill rakers allowed for mapping of phenotypic trajectories along the phylogeny. The phylogenetic and morphological analyses showed that the three sparsely rakered morphs were present at two extremes of the phylogenetic tree: the Yellow River morphs were located at the basal phylogenetic split, and the Lake Keluke and Ganzi River morphs at the peak, with the densely rakered Lake Qinghai morphs located between these two extremes. Age estimation further indicated that the sparsely rakered morphs constituted the oldest and youngest lineages, whereas the densely rakered morph was assigned to an intermediate-age lineage. These results are most compatible with the process of evolutionary convergence or reversal. Disruptive natural selection due to divergent habitats and dietary preferences is likely the driving force behind the formation of new morphs, and the similarities between their phenotypes may be attributable to the similarities between their forms of niche tracking associated with food acquisition. This study provides the first genetic evidence for the occurrence of convergence or reversal in the schizothoracine fish of the Tibetan Plateau at small temporal scales.

  3. Relationship between gullying and landslides within the Barlad Plateau, Romania

    Science.gov (United States)

    Niacsu, Lilian; Ionita, Ion

    2016-04-01

    Located in the eastern Romania and extending on 8200 km2 the Barlad Plateau is considered the most typical subunit of the Moldavian Plateau. The sedimentary Miocene-Pliocene clay-sandy layers, inter-bedded with shallow sandstone and limestone are gently dipping toward S-SE as homoclinal structure. Land degradation through soil erosion, gullying and landslides represent the most important environmental threat in the region. By using both the classical research methods such as repeated field surveys and mapping, mathematical-statistical processing as well as the present-day methods based on the GIS software it was possible to precisely measure and evaluate the gully erosion rates and triggered landslides during the last two centuries, especially with a very high accuracy since 1960. Results have indicated that the landslide development is strongly controlled by gullying. Generally, by combining the areal growth of both gullying and new landslides within the selected study catchments, it is noticeable that 62 % of the total recent land degradation occurred during the last 55 years, with the remainder pre-1960. In addition, half of the gully areal growth occurred since 1961 but the new triggered landslides amount over three-quarters of the total area under landslides. This asymmetrical distribution reveals that usually a preparing time lag of tens of years is required for triggering landslides by gullying and this pattern depicts the common mechanism for landslide development. Acknowledgements: This work was partly supported by a grant from the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, Project number PN-II-PT-PCCA-2011-3.2-0975.

  4. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-03-06

    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  5. Warming in Arctic intermediate and deep waters around Chukchi Plateau and its adjacent regions in 1999

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Jinping; GAO; Guoping

    2005-01-01

    Based on the data measured during Arctic scientific expedition of China in 1999, the characteristics of temperature and salinity distributions around the Chukchi Plateau and its adjacent regions have been studied. It was found that the intermediate water with temperature higher than 0.5℃ existed in all parts of a 640 km section with a maximum temperature of 0.85℃ indicating a strong signal of the warming in Arctic Intermediate Water in 1999. Two important phenomena are described in this paper. First, the temperature of warm water was horizontally nonuniform. In the area of Chukchi Plateau, the temperature was higher, the layer of warm water was thicker and the depth of the warm water core was shallower than those in the area of continental slope. The horizontal nonuniformity of the temperature distribution of warming water implies that the upward heat flux should also be nonuniform, thus exerting different effects on sea ice thickness, ice extent, and air-sea heat exchange. The mechanism to generate higher temperature in the plateau region was the bypassing of current around the plateau area caused by the special local topography, which restricted water exchange across the plateau and conserved heat in the water body. Second, the deep water down to 1400 m was also warming with a temperature increase of 0.2℃. The warming in deep water reflects the occurrence of complicated heat redistribution processes in the intermediate water, which altered the thermal structure in the upper 1400 m. The warming data embody the obvious impact of global climate change on the Arctic Ocean and further studies are wanted.

  6. On the nature of the plateau in two-step dinuclear spin-crossover complexes.

    Science.gov (United States)

    Ksenofontov, Vadim; Gaspar, Ana B; Niel, Virginie; Reiman, Sergey; Real, José A; Gütlich, Philipp

    2004-03-05

    A remarkable feature of the spin-crossover process in several dinuclear iron(II) compounds is a plateau in the two-step transition curve. Up to now, it has not been possible to analyse the spin state of dinuclear pairs that constitute such a plateau, due to the relative high temperatures at which the transition takes place in complexes investigated so far. We solved this problem by experimentally studying a novel dinuclear spin-crossover compound [[Fe(phdia)(NCS)(2)](2)(phdia)] (phdia: 4,7-phenanthroline-5,6-diamine). We report here on the synthesis and characterisation of this system, which exhibits a two-step spin transition at T(c1)=108 K and T(c2)=80 K, displaying 2 K and 7 K wide thermal hysteresis loops in the upper and the lower steps, respectively. A plateau of approximately 20 K width centred at about 90 K, which corresponds to the 50 % of the spin conversion, separates the two transitions. The composition of the plateau was identified in metastable state after quenching to 4.2 K by means of Mössbauer spectroscopy in an external magnetic field. Such experiments revealed that the plateau consists mainly of [HS-LS] pairs (HS=high spin, LS=low spin) and confirmed the hypothesis that the spin conversion in dinuclear entities proceeds through [LS-LS][HS-LS][HS-HS] pairs. The results are discussed in terms of a thermodynamic model based on the regular solution theory adapted for dinuclear spin-crossover compounds.

  7. Dynamic contact mechanics on the tibial plateau of the human knee during activities of daily living.

    Science.gov (United States)

    Gilbert, Susannah; Chen, Tony; Hutchinson, Ian D; Choi, Dan; Voigt, Clifford; Warren, Russell F; Maher, Suzanne A

    2014-06-27

    Despite significant advances in scaffold design, manufacture, and development, it remains unclear what forces these scaffolds must withstand when implanted into the heavily loaded environment of the knee joint. The objective of this study was to fully quantify the dynamic contact mechanics across the tibial plateau of the human knee joint during gait and stair climbing. Our model consisted of a modified Stanmore knee simulator (to apply multi-directional dynamic forces), a two-camera motion capture system (to record joint kinematics), an electronic sensor (to record contact stresses on the tibial plateau), and a suite of post-processing algorithms. During gait, peak contact stresses on the medial plateau occurred in areas of cartilage-cartilage contact; while during stair climb, peak contact stresses were located in the posterior aspect of the plateau, under the meniscus. On the lateral plateau, during gait and in early stair-climb, peak contact stresses occurred under the meniscus, while in late stair-climb, peak contact stresses were experienced in the zone of cartilage-cartilage contact. At 45% of the gait cycle, and 20% and 48% of the stair-climb cycle, peak stresses were simultaneously experienced on both the medial and lateral compartment, suggesting that these phases of loading warrant particular consideration in any simulation intended to evaluate scaffold performance. Our study suggests that in order to design a scaffold capable of restoring 'normal' contact mechanics to the injured knees, the mechanics of the intended site of implantation should be taken into account in any pre-clinical testing regime.

  8. Stable isotope variations (δ18O and δD) in modern waters across the Andean Plateau

    Science.gov (United States)

    Bershaw, John; Saylor, Joel E.; Garzione, Carmala N.; Leier, Andrew; Sundell, Kurt E.

    2016-12-01

    Environmental parameters that influence the isotopic composition of meteoric water (δ18O and δD) are well characterized up the windward side of mountains, where orographic precipitation results in a predictable relationship between the isotopic composition of precipitation and elevation. The topographic and climatic evolution of the Andean Plateau and surrounding regions has been studied extensively by exploiting this relationship through the use of paleowater proxies. However, interpretation on the plateau itself is challenged by a poor understanding of processes that fractionate isotopes during vapor transport and rainout, and by the relative contribution of unique moisture sources. Here, we present an extensive dataset of modern surface water samples for the northern Andean Plateau and surrounding regions to elucidate patterns and causes of isotope fractionation in this continental environment. These data show a progressive increase in δ18O of stream water west of the Eastern Cordillera (∼1‰/70 km), almost identical to the rate observed across the Tibetan Plateau, attributed to a larger fraction of recycled water in precipitation and/or increased evaporative enrichment downwind. This may lead to underestimates of paleoelevation, particularly for sites deep into the rainshadow of the Eastern Cordilleran crest. That said, elevation is a primary control on the isotopic composition of surface waters across the entire Andean Plateau and its flanks when considering the most negative δ18O values, highlighting the need for sufficiently large datasets to distinguish minimally evaporated samples. There is a general increase in δ18O on the plateau from north to south, concomitant with an increase in aridity and decrease in convective moistening (amount effect). Lastly, stable isotope and seasonal precipitation patterns suggest easterlies provide the vast majority of moisture that falls as precipitation across the Andean Plateau and Western Cordillera, from Peru to

  9. Variability in New Shortening Estimates from Southern Peru (12-14S); Implications for Mass Balance of the Andean Plateau.

    Science.gov (United States)

    Gotberg, N.; McQuarrie, N.

    2008-12-01

    One of the fundamental questions of interest with regards to the Andean Plateau is the mass balance of material needed to create and sustain a 3-4 km high plateau. Is crustal shortening sufficient to support an isostatically compensated crust of 60-70km? We present new estimates of shortening across the northern margin of the Andean Plateau. The cross section extent, from the eastern edge of the volcanic arc to foreland basin, is approximately one half of the physiographic width of the Andean Plateau in Peru. Cross sectional shortening estimates in southern Peru (12-14°S) provide a best estimate of 123 km or 40% shortening with an absolute minimum estimate of 86 km or 30% and absolute maximum estimate of 275 km or 60%. We determined the maximum and minimum shortening estimates using the cross sectional area and possible variations in assumptions made about the amount of erosion, detachment dip, involvement of basement thrusts and displacement along faults. The best estimate of shortening is well short of the required 240-300km of shortening needed in order to account for a 60-70km thick crust under the entire plateau. This suggests that for an isostatically equilibrated crust either 1) there is a significant amount of shortening (~150km) in the western half of the plateau which, is hidden by the volcanic arc or 2) crustal material is being added to the Peruvian section of the Andean Plateau either through lower crustal flow or a process of magmatic underplating followed by differentiation and delamination.

  10. Characteristics of land-atmosphere energy and turbulent fluxes over the plateau steppe in central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    MaoShan Li; ZhongBo Su; YaoMing Ma; XueLong Chen; Lang Zhang; ZeYong Hu

    2016-01-01

    The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the Tibetan Plateau (TP). Using observed data for Aug. 4 to Dec. 3, 2012 from the Bujiao observation point (BJ) of the Nagqu Plateau Climate and Environment Station (NPCE-BJ), different characteristics of the energy flux during the Asian summer monsoon (ASM) season and post-monsoon period were analyzed. This study outlines the impact of the ASM on energy fluxes in the central TP. It also demonstrates that the surface energy closure rate during the ASM season is higher than that of the post-monsoon period. Footprint modeling shows the distribution of data quality assessments (QA) and quality controls (QC) surrounding the observation point. The measured turbulent flux data at the NPCE-BJ site were highly rep-resentative of the target land-use type. The target surface contributed more to the fluxes under unstable conditions than under stable conditions. The main wind directions (180° and 210°) with the highest data density showed flux contributions reaching 100%, even under stable conditions. The lowest flux contributions were found in sectors with low data density, e.g., 90.4% in the 360° sector under stable conditions during the ASM season. Lastly, a surface energy water balance (SEWAB) model was used to gap-fill any absent or corrected turbulence data. The potential simulation error was also explored in this study. The Nash-Sutcliffe model efficiency coefficients (NSEs) of the observed fluxes with the SEWAB model runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season, but unrealistic values of−0.9 for latent heat flux during the post-monsoon period.

  11. Bartonella Species Detected in the Plateau Pikas (Ochotona curzoiae) from Qinghai Plateau in China.

    Science.gov (United States)

    Rao, Hua Xiang; Yu, Juan; Guo, Peng; Ma, Yong Cheng; Liu, Qi Yong; Jiao, Ming; Ma, Zhong Wen; Ge, Hua; Wang, Chun Xiang; Song, Xiu Ping; Shi, Yan; Li, Dong Mei

    2015-09-01

    Bartonella species can infect a variety of mammalian hosts and cause a broad spectrum of diseases in humans, but there have been no reports of Bartonella infection in Ochotonidae. This is the first study to detect Bartonella in plateau pikas in the Qinghai plateau, providing baseline data for the risk assessment of human Bartonella infection in this area. We obtained 15 Bartonella strains from 79 pikas in Binggou and Maixiu areas of Qinghai with a positive rate of 18.99%. Based on the phylogenetic analysis of the Bartonella citrate synthase (gltA) gene sequences, most strains were closely related to B. taylorii (3/15) and B. grahamii (12/15). The latter is a pathogenic strain in humans. Our results suggest that a corresponding prevention and control strategy should be taken into consideration in the Qinghai province.

  12. Extension of the Yellowstone plateau, eastern Snake River Plain, and Owyhee plateau

    Science.gov (United States)

    Rodgers, David W.; Hackett, William R.; Ore, H. Thomas

    1990-11-01

    Formation of the late Cenozoic volcanic province comprising the Owyhee plateau, eastern Snake River Plain, and Yellowstone plateau has been accompanied by east-northeast-directed crustal extension. A new vector of 45 mm/yr, N56°E for the migration of silicic volcanism across the volcanic province is calculated. If migration of volcanism reflects west-southwest continental drift over a mantle plume, a zone of crustal extension must separate the volcanic province from the more slowly moving North American craton. Space-time relations of basin fill in the adjacent Basin and Range province provide evidence for a zone of extension, about 125 km wide, coincident with and east of coeval silicic volcanism. Since 16 Ma, the zone of extension has migrated along with silicic volcanism, maintaining its position between the province and the unextended craton.

  13. Deep structure of the Iceland plateau

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.R.; Sacks, I.S.

    1979-11-10

    The topography of the sea floor between Iceland and Jan Mayen Island is flat and elevated in relation to most ocean basins. Marine geophysical observations in the area have shown that it was formed by sea floor spreading but have not revealed details of structures more than a few hundred meters beneath the sea floor. We have examined the dispersion of seismic surface waves across the Iceland Plateau and have modeled structures to depths of up to 100 km. We find that the thickness of the crustal component of the lithosphere is much greater than that of normal oceanic structures, perhaps exceeding 20 km. We suggest that the elevation of the region is due to isostatic compensation for this excess of low-density crustal material. The total lithospheric thickness is about 50 km throughout the region, indicating that the lithosphere thickens with age at a rate similar to that found in other young oceans.

  14. Plateau inflation in SUGRA-MSSM

    Science.gov (United States)

    Chakravarty, Girish Kumar; Gupta, Gaveshna; Lambiase, Gaetano; Mohanty, Subhendra

    2016-09-01

    We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU (2) Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  15. Plateau inflation in SUGRA-MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty

    2016-09-01

    Full Text Available We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU(2 Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  16. Multidisciplinary scientific program of investigation of the structure and evolution of the Demerara marginal plateau

    Science.gov (United States)

    Loncke, Lies; Basile, Christophe; Roest, Walter; Graindorge, David; Mercier de Lépinay, Marion; Klinghelhoefer, Frauke; Heuret, Arnauld; Pattier, France; Tallobre, Cedric; Lebrun, Jean-Frédéric; Poetisi, Ewald; Loubrieu, Benoît; Iguanes, Dradem, Margats Scientific Parties, Plus

    2017-04-01

    Mercier de Lépinay et al. published in 2016 an updated inventory of transform passive margins in the world. This inventory shows that those margins represent 30% of continental passive margins and a cumulative length of 16% of non-convergent margins. It also highlights the fact that many submarine plateaus prolong transform continental margins, systematically at the junction of oceanic domains of different ages. In the world, we identified twenty of those continental submarine plateaus (Falklands, Voring, Demerara, Tasman, etc). Those marginal plateaus systematically experiment two phases of deformation: a first extensional phase and a second transform phase that allows the individualization of those submarine reliefs appearing on bathymetry as seaward continental-like salients. The understanding of the origin, nature, evolution of those marginal plateaus has many scientific and economic issues. The Demerara marginal plateau located off French Guiana and Surinam belongs to this category of submarine provinces. The French part of this plateau has been the locus of a first investigation in 2003 in the framework of the GUYAPLAC cruise dedicated to support French submissions about extension of the limit of the continental shelf beyond 200 nautical miles. This cruise was the starting point of a scientific program dedicated to geological investigations of the Demerara plateau that was sustained by different cruises and collaborations (1) IGUANES (2013) that completed the mapping of this plateau including off Surinam, allowed to better understand the segmentation of the Northern edge of this plateau, and to evidence the combined importance of contourite and mass-wasting processes in the recent sedimentary evolution of this domain, (2) Collaboration with TOTAL (Mercier de Lépinay's PhD thesis) that allowed to better qualify the two main phases of structural evolution of the plateau respectively during Jurassic times for its Western border, Cretaceous times for its

  17. Have Periprosthetic Hip Infection Rates Plateaued?

    Science.gov (United States)

    Perfetti, Dean C; Boylan, Matthew R; Naziri, Qais; Paulino, Carl B; Kurtz, Steven M; Mont, Michael A

    2017-07-01

    Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). Although the number of revision cases is increasing, the prevalence of PJI as an indication for revision surgery, and the variability of this indication among surgeons and hospitals, is unclear. The New York Statewide Planning and Research Cooperative System was used to identify 33,582 patients undergoing revision THA between 2000 and 2013. PJI was identified using International Classification of Diseases, Ninth Revision diagnosis codes. Volume was defined using mean number of revision THAs performed annually by each hospital and surgeon. PJI was the indication for 13.0% of all revision THAs. The percentage of revision THAs for PJI increased between years 2000 and 2007 (odds ratio [OR] = 1.05, P < .001), but decreased between years 2008 and 2013 (OR = 0.96, P = .001). Compared to medium-volume hospitals, the PJI burden at high-volume hospitals decreased during years 2000-2007 (OR = 0.58, P < .001) and 2008-2013 (OR = 0.57, P < .001). Compared to medium-volume surgeons, the PJI burden for high-volume surgeons increased during years 2000-2007 (OR = 1.39, P < .001), but did not differ during years 2008-2013 (P = .618). The burden of PJI as an indication for revision THA may be plateauing. High-volume institutions have seen decreases in the percentage of revisions performed for PJI over the complete study duration. Specific surgeon may be associated with the plateauing in PJI rates as high-volume surgeons in 2008-2013 were no longer found to be at increased risk of PJI as an indication for revision THA. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Microwave assisted synthesis of a series of charge-transfer photosensitizers having quinoxaline-2(1H)-one as anchoring group onto TiO2 surface

    Science.gov (United States)

    Caicedo, Mauricio; Echeverry, Carlos A.; Guimarães, Robson R.; Ortiz, Alejandro; Araki, Koiti; Insuasty, Braulio

    2017-04-01

    In this work, we present the synthesis of novel donor-acceptor compounds based on 3-methylquinoxaline-2(1H)one which follow an easy synthetic route, involving Knoevenagel reaction with electron-donor groups such as N,N-dimethylaminobenzene, ferrocene, triphenylamine (TPA) and ((E)-4,4'-(ethene-1,2-diyl) bis (N,N-diphenylaniline). Additionally, the optical properties were measured by means of the absorption and emission spectroscopy suggesting a push-pull behavior which was further confirmed by electrochemical experiments. Finally, the quinoxaline-2(1H)one fragment not only bestow wide absorption, but also can chelate to titanium ions on the TiO2 surface, allowing a strong electron coupling between the excited-state energy level of the dyes and the conduction band of TiO2.

  19. Synthesis of some novel pyrazolo[3,4-d] pyrimidin-4(5H-one derivatives as potential antimicrobial agent

    Directory of Open Access Journals (Sweden)

    Dipen K Sureja

    2016-01-01

    Full Text Available Objectives: The aim of the present work was to synthesize a novel series of pyrazolo[3,4-d]pyrimidin-4(5H-one derivatives and evaluate their in vitro antimicrobial activity. Methods: Cyclization of an ortho-amino ester of 1-(2,4-dinitrophenylpyrazole with various aliphatic/aromatic nitriles under different reaction conditions such as conventional and microwave assisted synthesis, provided pyrazolo[3,4-d] pyrimidin-4(5H-one derivatives. All the synthesized compounds were evaluated in vitro for their antimicrobial activity against selected bacteria and fungi by agar well diffusion method. Results: All newly synthesized compounds were characterized using spectral and elemental analysis. Compounds 2e, 2f, and 2g showed significant antimicrobial activity as compared to standard drugs used. Conclusion: The newly synthesized compounds could be useful templates for the design and optimization of more active analogs as a possible antimicrobial agent.

  20. Design of a Simple Honing Apparatus for Engine Cylinder Hole%发动机缸孔简易珩磨装置的设计

    Institute of Scientific and Technical Information of China (English)

    董学平; 唐宁

    2011-01-01

    设计了一套安装在立式钻床上使用的发动机缸孔简易珩磨装置,解决了某些汽车、摩托车修理厂家因为没有珩磨机而无法进行发动机缸孔珩磨加工之困难。本装置结构简单,制造容易,成本低,使用方便。%A simple honing apparatus for engine cylinder hole installed in vertical drilling machine was designed to solve difficulties for some automobile and motorcycle repair shop because of no honing machine.The apparatus is simple in structure,easy to make,low

  1. Design, synthesis, and biological evaluation of 3-vinyl-quinoxalin-2(1H)-one derivatives as novel antitumor inhibitors of FGFR1

    Science.gov (United States)

    Liu, Zhiguo; Yu, Shufang; Chen, Di; Shen, Guoliang; Wang, Yu; Hou, Leping; Lin, Dan; Zhang, Jinsan; Ye, Faqing

    2016-01-01

    FGFR1 is well known as a molecular target in anticancer drug design. TKI258 plays an important role in RTK inhibitors. Utilizing TKI258 as a lead compound that contains a quinazolinone nucleus, we synthesized four series of 3-vinyl-quinoxalin-2(1H)-one derivatives, a total of 27 compounds. We further evaluated these compounds for FGFR1 inhibition ability as well as cytotoxicity against four cancer cell lines (H460, B16-F10, Hela229, and Hct116) in vitro. Some compounds displayed good-to-excellent potency against the four tested cancer cell lines compared with TKI258. Structure–activity relationship analyses indicated that small substituents at the side chain of the 3-vinyl-quinoxalin-2(1H)-one were more effective than large substituents. Lastly, we used molecular docking to obtain further insight into the interactions between the compounds and FGFR1. PMID:27217720

  2. Design, synthesis, and biological evaluation of 3-vinyl-quinoxalin-2(1H)-one derivatives as novel antitumor inhibitors of FGFR1.

    Science.gov (United States)

    Liu, Zhiguo; Yu, Shufang; Chen, Di; Shen, Guoliang; Wang, Yu; Hou, Leping; Lin, Dan; Zhang, Jinsan; Ye, Faqing

    2016-01-01

    FGFR1 is well known as a molecular target in anticancer drug design. TKI258 plays an important role in RTK inhibitors. Utilizing TKI258 as a lead compound that contains a quinazolinone nucleus, we synthesized four series of 3-vinyl-quinoxalin-2(1H)-one derivatives, a total of 27 compounds. We further evaluated these compounds for FGFR1 inhibition ability as well as cytotoxicity against four cancer cell lines (H460, B16-F10, Hela229, and Hct116) in vitro. Some compounds displayed good-to-excellent potency against the four tested cancer cell lines compared with TKI258. Structure-activity relationship analyses indicated that small substituents at the side chain of the 3-vinyl-quinoxalin-2(1H)-one were more effective than large substituents. Lastly, we used molecular docking to obtain further insight into the interactions between the compounds and FGFR1.

  3. Studies on the chemical behavior of 3-(nitroacetyl)-1-ethyl-4-hydroxyquinoline-2(1H)-one towards some electrophilic and nucleophilic reagents

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Magdy A.; Hassanin, Hany M.; Gabr, Yassin A.; Alnamer, Youssef A., E-mail: magdy_ahmed1977@yahoo.com [Department of Chemistry, Faculty of Education, Ain Shams University, Cairo (Egypt)

    2012-05-15

    A variety of heterocyclic systems linked to 1-ethylquinolin-2(1H)-one was prepared from reaction of 3-(nitroacetyl)-1-ethyl-4-hydroxyquinoline-2(1H)-one with some electrophilic and nucleophilic reagents. Besides its cyclization to 5-ethyl-2-(hydroxyimino)-2,3,4,5- tetrahydrofuro[3,2-c]quinoline-3,4-dione, the 3-(nitroacetyl)-1-ethyl-4-hydroxyquinoline-2(1H)- one has been brominated, chlorinated, formylated, acetylated, and condensed with chromone-3- carbonitrile and 2-amino-3-formylchromone. Some new pyrazolo[4,3-c]quinoline, pyrimido[5,4-c] quinoline and quinolino[4,3-b][1,5]benzodiazepine derivatives were also synthesized. (author)

  4. Synthesis, cytotoxic and antibacterial activities of 6-bromobenzo[d]thiazol-2(3H-one-[1,2,3] triazole hybrids

    Directory of Open Access Journals (Sweden)

    Vasudeva Reddy Nagavelli

    2016-07-01

    Full Text Available A series of new 6-bromobenzo[d]thiazol-2(3H-one derived 1,2,3-triazole derivatives (3a-j have been synthesized by 1,3-dipolar cycloaddition of 6-bromobenzo[d]thiazol-2(3H-one (2 with propargyl bromide and different aryl azides in a copper catalyzed one-pot reaction. All the synthesized compounds (3a-j were evaluated for their in vitro cytotoxic activity against two human cancer cell lines MCF-7 and HeLa. The results showed that these compounds showed good cytotoxicity against the tested cell lines as compared with that of standard drug Cisplatin. The antibacterial activity of the newly synthesized triazole derivatives (3a-j were also studied against different bacteria. The activity results showed that majority of compounds showed good to moderate antibacterial activity compared with positive control drug Streptomycin.

  5. Long-term, deep-mantle support of the Ethiopia-Yemen Plateau

    Science.gov (United States)

    Sembroni, Andrea; Faccenna, Claudio; Becker, Thorsten W.; Molin, Paola; Abebe, Bekele

    2016-04-01

    Ethiopia is a key site to investigate the interactions between mantle dynamics and surface processes because of the presence of the Main Ethiopian Rift (MER), Cenozoic continental flood basalt volcanism, and plateau uplift. The role of mantle plumes in causing Ethiopia's flood basalts and tectonics has been commonly accepted. However, the location and number of plumes and their impact on surface uplift are still uncertain. Here, we present new constraints on the geological and topographic evolution of the Ethiopian Plateau (NW Ethiopia) prior to and after the emplacement of the large flood basalts (40-20 Ma). Using geological information and topographic reconstructions, we show that the large topographic dome that we see today is a long-term feature, already present prior the emplacement of the flood basalts. We also infer that large-scale doming operated even after the emplacement of the flood basalts. Using a comparison with the present-day topographic setting we show that an important component of the topography has been and is presently represented by a residual, non-isostatic, dynamic contribution. We conclude that the growth of the Ethiopian Plateau is a long-term, probably still active, dynamically supported process. Our arguments provide constraints on the processes leading to the formation of one of the largest igneous plateaus on Earth.

  6. Holocene climate change in the Central Tibetan Plateau inferred by lacustrine sediment geochemical records

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Multi-proxies of lacustrine sediments, such as total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), hydrogen index (HI), oxygen index (OI) and stable carbon isotopic composition of organic matter (δ13Corg), were analyzed using a 7.3 m core from Zigê Tangco. The source of the organic matter in the sediment was mainly from autochthonous phytoplankton, therefore the significances of proxies can be interpreted as that high TOC, TOC/TS, HI and δ13Corg values, low TC, TIC values corresponded to warm and wet climatic condition, and vice versa. The process of climatic development in the Zigê Tangco region was hence recovered. During the early and Mid-Holocene, the climate was warm and wet and intensive cold events occurred during the periods of 8600 to 8400 cal a BP and 7400 to 7000 cal a BP. In the second half of Holocene, the climate became cold and dry gradually. The palaeoclimatic process during Holocene in Zigê Tangco region matched well with that in Co Ngoin region which is ca 40 km to the south-east. Therefore this palaeoclimatic process represents the Holocene climatic feature in the Central Tibetan Plateau which has the same pattern in the Northern Tibetan Plateau, but the time and duration of some climatic events might be different. We can conclude that in Holocene solar insolation controlled the climatic pattern on the central Tibetan Plateau.

  7. An ecosystem approach to combat desertification on the Colorado Plateau.

    Science.gov (United States)

    Clements, Amanda

    2004-12-01

    Desertification of shrub and grassland into pinyon-juniper woodland is occurring over much of the Colorado Plateau in the southwestern United States. As trees invade, they out-compete shrubs and grasses, increasing erosion rates and reducing infiltration of moisture into the soil. This has caused habitat problems for wildlife, and reduced forage for livestock. These impacts also affect the human communities that rely on ranching and tourism related to hunting. Past land use and management practices including heavy livestock grazing, fire suppression and introduction of exotic annual plants are believed to have led to current conditions. The Montrose office of the Bureau of Land Management has implemented an ecosystem-based program to reverse the desertification process on public land. The program is centered on detailed landscape objectives describing the desired vegetation mosaic on 360,000 ha of public land. The objectives outline proportions of plant seral stages and arrays of patch sizes for each planning unit. These objectives are based on priority management issues and the need to replicate a natural vegetation mosaic. Where the existing mosaic does not meet objectives, mechanical vegetation treatments and prescribed fire are used to create early and mid-seral patches on the ground. This restored vegetation pattern and type should be sustained over time through a natural fire regime and improved livestock management. Because many uncertainties exist, an adaptive management process is being used that allows mosaic objectives to be changed or processes modified where monitoring or scientific research indicate a need.

  8. Brøsted Acidic Ionic Liquid ([Bmim]Hso4 Promoted Cyclocodensation Reaction: Synthesis of 3,4,5-Substituted Furan-2(5h-Ones

    Directory of Open Access Journals (Sweden)

    Sajjad Salahi

    2015-12-01

    Full Text Available 1-Butyl-3-methylimidazolium hydrogen sulfate [bmim]HSO4: an acidic ionic liquid was used as a catalyst for the synthesis of heterocyclic compounds 3,4,5-substituted furan-2(5H-ones from aniline derivatives, dialkyl acetylenedicarboxylates and aromatic aldehydes at 75 °C. Solvent-free conditions, shorter reaction time, and good yields (71-94% are some of advantages.

  9. Efficient synthesis of 5,6-dihydrothieno[3',2':4,5]-thieno[2,3-d]pyrimidin-4(3H)-ones via an iminophosphorane

    Institute of Scientific and Technical Information of China (English)

    Yu Lu Chen; Yi Bo Nie; Ming Wu Ding

    2009-01-01

    5,6-Dihydrothieno[3',2':4,5]thieno[2,3-d]pyrimidin-4(3H)-ones 6 were synthesized in yields of 71-87% by a consecutive method,which includes aza-Wittig reaction of iminophosphorane 3 with aromatic isocynate to give carbodiimide 4 and subsequent reaction of 4 with various amines,phenols or alcohols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate.

  10. 2-(Pyrrolidin-1-yl)ethyl-3,4-dihydroisoquinolin-1(2H)-one derivatives as potent and selective histamine-3 receptor antagonists.

    Science.gov (United States)

    Zhou, Dahui; Gross, Jonathan L; Adedoyin, Adedayo B; Aschmies, Suzan B; Brennan, Julie; Bowlby, Mark; Di, Li; Kubek, Katie; Platt, Brian J; Wang, Zheng; Zhang, Guoming; Brandon, Nicholas; Comery, Thomas A; Robichaud, Albert J

    2012-03-08

    On the basis of the previously reported benzimidazole 1,3'-bipyrrolidine benzamides (1), a new class of 2-(pyrrolidin-1-yl)ethyl-3,4-dihydroisoquinolin-1(2H)-one derivatives (3-50) were synthesized and evaluated as potent H(3) receptor antagonists. In particular, compound 39 exhibited potent in vitro binding and functional activities at the H(3) receptor, good selectivities against other neurotransmitter receptors and ion channels, acceptable pharmacokinetic properties, and a favorable in vivo profile.

  11. Pyridinium Trifluoro Acetate Mediated Synthesis of 3,4-Dihydropyrimidin-2(1H-ones and Tetrazolo[1,5-a]pyrimidine-6-carboxylates

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Sridhar

    2012-01-01

    Full Text Available A simple and economic synthesis of 3,4-dihydropyrimidin-2(1H-ones using pyridinium triflate as catalyst under microwave condition was attempted with an easy work-up protocol. Further tetrazolo [1,5-a] pyrimidine-6-carboxylates were synthesized by three-component coupling reaction of β-ketoesters with a mixture of aromatic aldehyde and 5-aminotetrazole. The products were well characterized with IR, NMR (1H and 13C NMR and mass spectrometry.

  12. Two epithelial tumor cell lines (HNE-1 and HONE-1) latently infected with Epstein-Barr virus that were derived from nasopharyngeal carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, R.; Zhang, Haizhang (Ohio State Univ. Medical Center, Columbus (USA)); Yao, Kaitai; Zhu, Hecheng; Wang, Fuxi; Li, Guiyuan; Wen, Dongseng; Li, Yingping (Hunan Medical Univ., Changsha (China))

    1989-12-01

    Two epithelia tumor cell lines were established from biopsy specimens of nasopharyngeal carcinomas (NPC). The specimens were taken from poorly differentiated squamous cell carcinomas of the nasopharynx. The tissues were prepared for cell culture and eventually two continuous epithelia cell lines were obtained and designated HONE-1 and HNE-1. Light and electron microscopic examination of these two cell lines demonstrated cells with an epithelial morphology including the presence of desmosomes. It was found that early-passage uncloned HNE-1 cells (passage 23) could be superinfected with B95-8 and NPC-EBV isolates as demonstrated by the induction of Epstein-Barr virus (EBV)-specific early antigen(s) in a small percentage of the cells; HONE-1 cells could also be superinfected with EBV. Southern blot analysis detected EBV DNA in samples from uncloned HNE-1 cells at passages 12, 17, 21, 27, and 35. However, by passage 45, EBV DNA could no longer be detected in HNE-1 cells by Southern blot analysis. The EBV genome was detected in parental HONE-1 cells at subculture 9 and in clone 40 cells up to passage 40 thus far. The data suggest that EBV genome-positive HNE-1 and HONE-1 cells were lost as the cells were cultivated in vitro and that cloning the cells at an early passage level may be critical in maintaining EBV genome-positive epithelial NPC cells. These EBV genome-positive epithelia NPC cell lines will be useful for studying the association of EBV and NPC.

  13. Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

    Institute of Scientific and Technical Information of China (English)

    Khodabakhsh; Niknam; Alireza; Hasaninejad; Madihe; Arman

    2010-01-01

    Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

  14. Design and Synthesis of Novel 5-Sulfoxide-substituted Pyrazolo[5,1-d] [1,2,3,5]tetrazin-4(3H)ones

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of novel 5-sulfoxide-substituted pyrazolo[5,1-d][1,2,3,5]tetrazin-4(3H)ones 4a-j were designed and efficiently synthesized via a diazotization of 5-amine-3-methylsulfinyl1H-pyrazole, followed by cycloaddition with aryl isocyanate. A possible reaction mechanism is outlined and discussed. These new compounds exhibit some biological activity as preliminary bioassay indicated. Their structures were confirmed with1 H NMR, IR and elemental analysis.

  15. Synthesis of Some Novel 2,6-Disubstituted Pyridazin-3(2H)-one Derivatives as Analgesic, Anti-Inflammatory, and Non-Ulcerogenic Agents.

    Science.gov (United States)

    Ibrahim, Tamer H; Loksha, Yasser M; Elshihawy, Hosam A; Khodeer, Dina M; Said, Mohamed M

    2017-09-01

    Some novel 2,6-disubstituted pyridazine-3(2H)-one derivatives were synthesized and evaluated for in vitro cyclooxygenase-2 (COX-2) inhibitory efficacy. Compounds 2-{[3-(2-methylphenoxy)-6-oxopyridazin-1(6H)-yl]methyl}-1H-isoindole-1,3(2H)-dione (5a), 2-propyl-6-(o-tolyloxy)pyridazin-3(2H)-one (6a), and 2-benzyl-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazin-3(2H)-one (16a) showed the most potent COX-2 inhibitory activity with IC50 values of 0.19, 0.11, and 0.24 μM, respectively. The synthesized compounds with the highest COX-2 selectivity indices were evaluated for their anti-inflammatory, analgesic, and ulcerogenic activities. Compounds 6a and 16a demonstrated the most potent and consistent anti-inflammatory activity over the synthesized compounds, which was significantly higher than that of celecoxib in the carrageenin rat paw edema model and with milder ulcer scoring than that of indomethacin in the ulcerogenicity screening. © 2017 Deutsche Pharmazeutische Gesellschaft.

  16. High Voltage Plateau and Data Reliability Test for the DSNC Troubleshooting

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwang-June; Jeong, Jeong-Whan; Kang, Hee-Young; Shin, Hee-Sung; Kim, Ho-Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    DSNC(Dupic safeguard neutron counter) was installed in the Dupic fuel development facility (DFDF) for the nuclear material accounting in the end of 1990s and had operated normally until 2003. But there have been a problem after that time. It has an abnormal state in the function of counting the neutrons emitting from the Dupic process product as well as the spent nuclear fuel at present. In this study, high voltage plateau and data acquisition reliability test were carried out as a method of troubleshooting for DSNC. As a result of the test, it was confirmed that the high voltage plateau was not formed but data acquisition reliability was good at some high voltages and at 6V applied to the electronic circuit of the counter.

  17. Evolution of Chinese mammalian faunal regions and elevation of the Qinghai-Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    QIU Zhuding; LI Chuankui

    2005-01-01

    On the basis of mammal's high evolutionary rates and sensitivity to environment, this paper deals with the evolutionary history of the Chinese Cenozoic mammals and environmental changes, and explores the relationship between the uplift of the Qinghai-Xizang Plateau and the evolution of zoogeographic provinces of China, through studying fossil mammal and the lithological characters of fossil-bearing beds. Evolutionary tendency and distribution of the mammals demonstrate that the uplift of the Qinghai-Xizang region, onset of the Asian monsoon and differentiation of the mammalian distribution probably initiated in Oligocene. The elevation of the Plateau seems to be a gradual and relatively stable process, and the uplift not only has resulted in significant environmental changes in Asia, but also caused distinct regional differentiation of mammals in China since the middle Miocene, and as a consequence the modern zoogeographic provinces gradually took shape.

  18. Agrobiodiversity of cactus pear (Opuntia, Cactaceae in the Meridional Highlands Plateau of Mexico

    Directory of Open Access Journals (Sweden)

    Juan Antonio Reyes-Agüero

    2011-08-01

    Full Text Available Mexico is characterized by a remarkable richness of Opuntia, mostly at the Meridional Highlands Plateau; it is also here where the greatest richness of Opuntia variants occurs. Most of these variants have been maintained in homegardens; however, the gathering process which originated these homegardens has been disrupted over the past decades, as a result of social change and the destruction of large wild nopaleras. If the variants still surviving in homegardens are lost, these will be hard to recover, that is, the millenary cultural heritage from the human groups that populated the Mexican Meridional Highland Plateau will be lost forever. This situation motivated the preparation of a catalogue that records the diversity of wild and cultivated Opuntia variants living in the meridional Highlands Plateau. To this end, 379 samples were obtained in 29 localities, between 1998 and 2003. The information was processed through Twinspan. All specimens were identified and preserved in herbaria. Botanical keys and descriptions were elaborated. The catalogue includes information on 126 variants comprising 18 species. There were species with only one variant (Opuntia atropes, O. cochinera, O. jaliscana, O. leucotricha, O. rzedowskii and O. velutina, two (O. durangensis, O. lindheimeri, O. phaeacantha and O. robusta, five (O. joconostle and O. lasiacantha, seven (O. chavena, 12 (O. hyptiacantha and O. streptacantha, 15 (O. ficus-indica, 22 (O. albicarpa, and up to 34 (O. megacantha. Additionally, 267 common cactus pear names were related to those variants.

  19. A Convenient Approach to Heterocyclic Building Blocks: Synthesis of Novel Ring Systems Containing a [5,6]Pyrano[2,3-c]pyrazol-4(1H-one Moiety

    Directory of Open Access Journals (Sweden)

    Wolfgang Holzer

    2007-01-01

    Full Text Available Starting from commercially available educts, a straightforward synthetic route to new heterocyclic building blocks is exemplified with the one- or two-step synthesis of tri-, tetra-, or pentacyclic ring systems. Representatives of the following novel ring systems are prepared from 3-methyl-1-phenyl-2-pyrazolin-5-one and the corresponding o-halo-arenecarbonyl chloride using calcium hydroxide in refluxing 1,4-dioxane: pyrimidino[4',5':5,6]pyrano[2,3-c]pyrazol-4(1H-one, thieno[3',2':5,6]pyrano[2,3c]pyrazol- 4-(1H-one, thieno[3',4':5,6]pyrano[2,3-c]pyrazol-4(1H-one, thieno[3'',2'':4',5']thieno[2',3':5,6]-pyrano[2,3-c]pyrazol-4(1H-one, [1,3]dioxolo[5',6'][1]benzothieno[2',3':5,6]pyrano-[2,3-c]- pyrazol-4(1H-one, pyridazino[4',3':5,6]pyrano[2,3-c]pyrazol-4(1H-one and pyrazolo-[4'',3'':5',6']pyrido[3',4':5,6]pyrano[2,3-c]pyrazol-4(1H-one. While the latter two ring systems are directly obtained due to a spontaneous intramolecular substitution reaction, in the other reactions uncyclised 4-aroylpyrazol-5-ols are produced, which are cyclised into the target heterocycles in a subsequent synthetic step (i.e. treatment with NaH in DMF. Detailed NMR spectroscopic investigations (1H-, 13C-, 15N- with the obtained compounds were undertaken to unambiguously prove the new structures.

  20. Total knee arthroplasty and fractures of the tibial plateau

    Science.gov (United States)

    Softness, Kenneth A; Murray, Ryan S; Evans, Brian G

    2017-01-01

    Tibial plateau fractures are common injuries that occur in a bimodal age distribution. While there are various treatment options for displaced tibial plateau fractures, the standard of care is open reduction and internal fixation (ORIF). In physiologically young patients with higher demand and better bone quality, ORIF is the preferred method of treating these fractures. However, future total knee arthroplasty (TKA) is a consideration in these patients as post-traumatic osteoarthritis is a common long-term complication of tibial plateau fractures. In older, lower demand patients, ORIF is potentially less favorable for a variety of reasons, namely fixation failure and the need for delayed weight bearing. In some of these patients, TKA can be considered as primary mode of treatment. This paper will review the literature surrounding TKA as both primary treatment and as a salvage measure in patients with fractures of the tibial plateau. The outcomes, complications, techniques and surgical challenges are also discussed.

  1. Phylogeography of regional fauna on the Tibetan Plateau: A review

    Institute of Scientific and Technical Information of China (English)

    Shujuan Yang; Hailiang Dong; Fumin Lei

    2009-01-01

    The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the pla-teau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range con-tractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

  2. The Colorado Plateau coal assessment study area, 2000 (cpstdyg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a coverage of the Colorado Plateau coal assessment study area. The study area outline was drawn on the county lines that most closely outline the...

  3. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    Turned multifunctional surfaces are a new typology of textured surfaces presenting a flat plateau region and deterministically distributed lubricant reservoirs. Existing standards are not suitable for the characterization of such surfaces, providing at times values without physical meaning. A new...

  4. Flora investigation kicks off on Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Coordinated by the CAS Kunming Institute of Botany,a project to investigate the floral germplasm resources on the Qinghai-Tibet Plateau was initiated recently in Kunming,capital of southwest China's Yunnan Province.

  5. Changes in lake areas on the Tibetan Plateau from 1972 to present

    Science.gov (United States)

    Abbey, A. L.; Hudson, A. M.; Kapp, P. A.; Quade, J.

    2012-12-01

    We determined changes in th areas of selected lakes on the Qinghai-Tibetan Plateau, from the 1970's to present, to evaluate their significance in terms of lake hydrology and climate. The Qinghai-Tibetan Plateau is covered by thousands of lakes ranging in size from a few square kilometers to several thousand square kilometers. Many of the lakes are located in internally drained basins, where lake area can be used as a direct indicator of the hydrologic budget within the basin. Eight internally drained lakes were chosen to represent four regions on the plateau (NE, NW, SE, and SW); in each region, one lake basin is fed by glacial runoff and one lake basin has no modern glaciers, in its catchment area. For each lake, classification mapping was done using ArcGIS and Landsat images from the 1970's to present. Changes in lake area were measured by extracting the pixels that made up the lake in each image. Lake area time series for each basin showed that between 1972 and 1997 lake level decreased or had no change (0% to -25%). From 1998 to present, all lakes show an increasing trend in area, ranging from 2% - 108%. Precipitation over the study period has not changed significantly, and not equally in all regions, and therefore is an unlikely explanation for lake expansion. Although glacier melt may be contributing to the increase in lake areas in glaciated watersheds, this cannot the lake area increases in non-glaciated watersheds. In contrast to changes in regional precipitation, mean annual temperature has been increasing relatively uniformly across the plateau since the 1950's. The plateau is almost entirely covered in frozen ground, and in response to these warmer air temperatures (and average annual ground temperatures), the frozen ground has been degrading over the past 50 years. We suggest that a threshold temperature was reached in 1998 that caused accelerated permafrost degradation, and since then, permafrost melting has been an important process contributing to

  6. Impact of Cryosphere Hydrological Changes on the River Runoff in the Tibetan Plateau

    Science.gov (United States)

    Wang, Y.; Yang, D.

    2015-12-01

    The Tibetan Plateau is the headwaters of many major rivers in Asia, the change in streamflow is significant for social and economic development and natural ecology in the middle and lower reaches. Located in the alpine region, streamflow in the plateau is mainly affected by the cryosphere hydrological processes. Due to global warming in recent decades, the Tibetan Plateau is experiencing glaciers shrinking and permafrost degradation. Accelerated glacier melt led to the increasing meltwater, thus affecting the streamflow. Permafrost is an important factor in stabilizing the water cycle and streamflow, the ecological degradation and the significant changes of rivers, lakes, swamps, wetlands and other hydrological environment in recent decades in the Tibetan plateau is closely related to permafrost degradation. Therefore, it is important to explore the impact of cryosphere hydrological changes on the streamflow for the future water management. This study uses a method of base flow separation and a stepwise multiple regression model to investigate the reasons for the runoff changes in different regions of the Tibetan Plateau during 1960-2000. The contribution of glacier melt to annual runoff is particularly estimated to explore the possible influences of soil freezing and thawing on annual runoff changes. The results show an increasing trend of the annual runoff in the upstream of Nujiang River, Lancang River and Qilian Mountains, dominated by the increasing of base flow; and a decreasing trend of the runoff in the upper reach of the Yarlung Zangbo River, Yellow River and Yangtze River, dominated by the reduction of quick flow. Change in the amount of runoff was mainly due to change in precipitation. Rising temperature accelerates the melting of glaciers and increases the summer quick flow. In addition, rising temperature may reduce the quick flow and increase the base flow due to change of the active permafrost layers, which leads to the increase of soil water storage

  7. 变齿厚齿轮的珩齿加工%Honing Process for Involute Beveloid Gear

    Institute of Scientific and Technical Information of China (English)

    王智礼; 沈永鹤; 徐锋; 周丽文

    2007-01-01

    介绍了一种变齿厚齿轮的珩齿加工方法.根据变齿厚齿轮的几何特征,选用蜗杆式珩磨轮来珩削变齿厚齿轮方案,并且设计了一套简便实用的定压浮动珩齿装置.通过珩齿加工后,降低了变齿厚齿轮的齿面粗糙度,提高了齿轮精度.

  8. The effect of up-regulating miR-34c-5p on the proliferation and invasion of nasopharyngeal carcinoma cell line HONE-1%上调miR-34c-5p对鼻咽癌细胞HONE-1增殖和侵袭的影响

    Institute of Scientific and Technical Information of China (English)

    马菲菲; 郝彦强; 王国强; 张鑫; 郅程; 冀天星

    2015-01-01

    Objective To investigate the effect of up-regulating miR-34c-5p on cloning formation and migration of nasopharyngeal carcinoma cell line HONE-1 in vitro. Methods Expression levels of miR-34c-5p in nasopharyngeal cell line NP69 and nasopharyngeal carcinoma cell line HONE-1 were investigated by real time quantitative PCR;Cloning Forma⁃tion Test and Transwell Migration Assay were used to explore the effect of up-regulating miR-34c-5p on proliferation and migration of nasopharyngeal carcinoma cell line HONE-1. Results The expression of miR-34c-5p in nasopharyngeal car⁃cinoma cell line HONE-1 was lower than that in normal nasopharyngeal cell line NP69. Up-regulating miR-34c-5p signifi⁃cantly suppressed the cloning formation and migration capacity, compared to those of NP69 cell line and HONE-1 with nor⁃mal level of miR-34c-5p(P<0.05). Conclusion Down-regulating miR-34c-5p involve in proliferation and migration of nasopharyngeal carcinoma and may be a used as a new therapeutic target for nasopharyngeal carcinoma.%目的:探讨上调miR-34c-5p对鼻咽癌细胞HONE-1增殖和转移能力的影响。方法利用定量PCR分析miR-34c-5p在鼻咽癌细胞株HONE-1和正常鼻咽细胞株NP69中的表达情况;利用克隆形成实验和Transwell实验分析上调miR-34c-5p表达对miR-34c-5p mimic转染组、miR-34c-5p对照序列组和未处理组增殖和侵袭能力的影响。结果 miR-34c-5p在鼻咽癌细胞株HONE-1的表达水平低于正常鼻咽细胞株NP69;miR-34c-5p mimic转染组鼻咽癌细胞HONE-1的克隆形成和侵袭能力明显低于miR-34c-5p对照序列组和未处理组(均P<0.05)。结论 miR-34c-5p的下调与鼻咽癌的生物学功能增殖和侵袭能力相关,是鼻咽癌治疗的潜在靶点。

  9. The Colorado Plateau II : Biophysical, Socioeconomic, and Cultural Research

    OpenAIRE

    Van Riper, Charles; Mattson, David J.

    2005-01-01

    Abstract from GoogleBooks: The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by again focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through graz...

  10. The Colorado Plateau II : Biophysical, Socioeconomic, and Cultural Research

    OpenAIRE

    Van Riper, Charles; Mattson, David J.

    2005-01-01

    Abstract from GoogleBooks: The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by again focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through graz...

  11. AHP 21: Pyramid Schemes on the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Devin Gonier

    2017-09-01

    Full Text Available The unique features of pyramid shemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be reduced at both institutional and individual levels.

  12. Nutrient Lossed in Soils on Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    PENGLIN; WANGJI-ZENG; 等

    1995-01-01

    The soil nutrient losses due to excessive soil loss on Loess Plateau were studied by means of runoff plots and systematical determination of soil nutrients both in sediments and runoff.The results show that the amounts of nutrient losses depended on the amounts of ersoion sediments.Along with sediment,11-197kg nitrogen/hectare and 9-174kg phosphorus/hectare were lost,accounting for 92.46-99.47 percent of the total amount of nitrogen loss and 99.85-99.99 percent of the total amount of phosphorus loss respectively.The nutrient losses,very small in runoff,were mainly attributed to erosion of a few rainstorms during a year.The nutrient level in sediment was mostly higher than that in the original soil.Planting grass evidently redued the losses of soil nutrients.The N level was lower in runoff than in rainfall so that the N loss from runoff could be made up by rainfall.Fertilizer application to crops raised the nutrient level in runoff.

  13. Solution of the Kirchhoff-Plateau Problem

    Science.gov (United States)

    Giusteri, Giulio G.; Lussardi, Luca; Fried, Eliot

    2017-01-01

    The Kirchhoff-Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a liquid film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. We establish the existence of an equilibrium shape that minimizes the total energy of the system under the physical constraint of noninterpenetration of matter, but allowing for points on the surface of the bounding loop to come into contact. In our treatment, the bounding loop retains a finite cross-sectional thickness and a nonvanishing volume, while the liquid film is represented by a set with finite two-dimensional Hausdorff measure. Moreover, the region where the liquid film touches the surface of the bounding loop is not prescribed a priori. Our mathematical results substantiate the physical relevance of the chosen model. Indeed, no matter how strong is the competition between surface tension and the elastic response of the filament, the system is always able to adjust to achieve a configuration that complies with the physical constraints encountered in experiments.

  14. Dendroclimatic reconstructions for the southern Colorado plateau

    Energy Technology Data Exchange (ETDEWEB)

    Dean, J.S.; Funkhouser, G.S. [Univ. of Arizona, Tucson, AZ (United States)

    1995-09-01

    A geographical network of climate sensitive tree-ring chronologies consisting of 25 archaeological sequences and two bristlecone pine series provides the basis for high resolution reconstructions of low and high frequency climatic variability on the southern Colorado Plateau over the last 1,500 years. Qualitative and quantitative dendroclimatic analyses of these data produce annual retrodictions of yearly and seasonal precipitation and summer Palmer Drought Severity Indices for each station and reconstructions of regional scale patterns in climatic variability. These reconstructions provide detailed information on climatic fluctuations that affected biotic and human populations as well as long-term baseline data for evaluating present-day climate and estimating future climatic trends. When integrated with other measures of past environmental variability, these reconstructions specify periods of favorable and unfavorable environmental conditions that would have affected past human populations of the region. The severest degradation, which occurred between A.D. 1250 and 1450, probably was causally related to numerous cultural changes that occurred at the end of the l3th century including the Anasazi abandonment of the Four Comers area. Projecting environmental patterns that characterized the last two millennia into the future indicates potential hazards to long term uranium mill waste disposal and containment and the potential and limitations of environmental restoration.

  15. Does the climate warming hiatus exist over the Tibetan Plateau?

    Science.gov (United States)

    Duan, Anmin; Xiao, Zhixiang

    2015-09-02

    The surface air temperature change over the Tibetan Plateau is determined based on historical observations from 1980 to 2013. In contrast to the cooling trend in the rest of China, and the global warming hiatus post-1990s, an accelerated warming trend has appeared over the Tibetan Plateau during 1998-2013 (0.25 °C decade(-1)), compared with that during 1980-1997 (0.21 °C decade(-1)). Further results indicate that, to some degree, such an accelerated warming trend might be attributable to cloud-radiation feedback. The increased nocturnal cloud over the northern Tibetan Plateau would warm the nighttime temperature via enhanced atmospheric back-radiation, while the decreased daytime cloud over the southern Tibetan Plateau would induce the daytime sunshine duration to increase, resulting in surface air temperature warming. Meanwhile, the in situ surface wind speed has recovered gradually since 1998, and thus the energy concentration cannot explain the accelerated warming trend over the Tibetan Plateau after the 1990s. It is suggested that cloud-radiation feedback may play an important role in modulating the recent accelerated warming trend over the Tibetan Plateau.

  16. Does the climate warming hiatus exist over the Tibetan Plateau?

    Science.gov (United States)

    Duan, Anmin; Xiao, Zhixiang

    2015-01-01

    The surface air temperature change over the Tibetan Plateau is determined based on historical observations from 1980 to 2013. In contrast to the cooling trend in the rest of China, and the global warming hiatus post-1990s, an accelerated warming trend has appeared over the Tibetan Plateau during 1998–2013 (0.25 °C decade−1), compared with that during 1980–1997 (0.21 °C decade−1). Further results indicate that, to some degree, such an accelerated warming trend might be attributable to cloud–radiation feedback. The increased nocturnal cloud over the northern Tibetan Plateau would warm the nighttime temperature via enhanced atmospheric back-radiation, while the decreased daytime cloud over the southern Tibetan Plateau would induce the daytime sunshine duration to increase, resulting in surface air temperature warming. Meanwhile, the in situ surface wind speed has recovered gradually since 1998, and thus the energy concentration cannot explain the accelerated warming trend over the Tibetan Plateau after the 1990s. It is suggested that cloud–radiation feedback may play an important role in modulating the recent accelerated warming trend over the Tibetan Plateau. PMID:26329678

  17. Impact of the Anomalous Thawing in the Tibetan Plateau on Summer Precipitation in China and Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    GAO Rong; WEI Zhigang; DONG Wenjie; ZHONG Hailing

    2005-01-01

    The impact of the anomalous thawing of frozen soil in the late spring on the summer precipitation in China and its possible mechanism are analyzed in the context of the frozen soil thawing date data of the 50meteorological stations in the Tibetan Plateau, and the NCEP/NCAR monthly average reanalysis data.Results show that the thawing dates of the Tibetan Plateau gradually become earlier from 1980 to 1999,which is consistent with the trend of global warming in the 20th century. Because differences in the thermal capacity and conductivity between frozen and unfrozen soils are larger, changes in the freezing/thawing process of soil may change the physical properties of the underlying surface, thus affecting exchanges of sensible and latent heat between the ground surface and air. The thermal state change of the plateau ground surface must lead to the thermal anomalies of the atmosphere over and around the plateau, and then further to the anomalies of the general atmospheric circulation. A possible mechanism for the impact of the thawing of the plateau on summer (July) precipitation may be as follows. When the frozen soil thaws early (late) in the plateau, the thermal capacity of the ground surface is large (small), and the thermal conductivity is small (large), therefore, the thermal exchanges between the ground surface and the air are weak (strong). The small (large) ground surface sensible and latent heat fluxes lead to a weak (strong) South Asian high, a weak (strong) West Pacific subtropical high and a little to south (north) of its normal position. Correspondingly, the ascending motion is strengthened (weakened) and precipitation increases (decreases) in South China, while in the middle and lower reaches of the Changjiang River, the ascending motion and precipitation show the opposite trend.

  18. Crystal structure of fac-tricarbonylchloridobis(4-hydroxypyridinerhenium(I–pyridin-4(1H-one (1/1

    Directory of Open Access Journals (Sweden)

    Saray Argibay-Otero

    2017-10-01

    Full Text Available The asymmetric unit of the title compound, [ReCl(C5H5NO2(CO3]·C5H5NO, contains one molecule of the complex fac-[ReCl(4-pyOH2(CO3] (where 4-pyOH represents 4-hydroxypyridine and one molecule of pyridin-4(1H-one (4-HpyO. In the molecule of the complex, the Re atom is coordinated to two N atoms of the two 4-pyOH ligands, three carbonyl C atoms, in a facial configuration, and the Cl atom. The resulting geometry is slightly distorted octahedral. In the crystal structure, both fragments are associated by hydrogen bonds; two 4-HpyO molecules bridge between two molecules of the complex using the O=C group as acceptor for two different HO– groups of coordinated 4-pyOH from two neighbouring metal complexes. The resulting square arrangements are extented into infinite chains by hydrogen bonds involving the N—H groups of the 4-HpyO molecule and the chloride ligands. The chains are further stabilized by π-stacking interactions.

  19. 5-Aryl-2-(naphtha-1-yl)sulfonamido-thiazol-4(5H)-ones as clathrin inhibitors.

    Science.gov (United States)

    Robertson, Mark J; Horatscheck, André; Sauer, Samantha; von Kleist, Lisa; Baker, Jennifer R; Stahlschmidt, Wiebke; Nazaré, Marc; Whiting, Ainslie; Chau, Ngoc; Robinson, Phillip J; Haucke, Volker; McCluskey, Adam

    2016-11-29

    The development of a (Z)-5-((6,8-dichloro-4-oxo-4H-chromen-3-yl)methylene)-2-thioxothiazolidin-4-one (2), rhodanine-based lead that led to the Pitstop® 2 family of clathrin inhibitors is described herein. Head group substitution and bioisosteric replacement of the rhodanine core with a 2-aminothiazol-4(5H)-one scaffold eliminated off target dynamin activity. A series of N-substituents gave first phenylglycine (20, IC50 ∼ 20 μM) then phenyl (25, IC50 ∼ 7.1 μM) and 1-napthyl sulfonamide (26, Pitstop® 2 compound, IC50 ∼ 1.9 μM) analogues with good activity, validating this approach. A final library exploring the head group resulted in three analogues displaying either slight improvements or comparable activity (33, 38, and 29 with IC50 ∼ 1.4, 1.6 and 1.8 μM respectively) and nine others with IC50 < 10 μM. These results were rationalized using in silico docking studies. Docking studies predicted enhanced Pitstop® 2 family binding, not a loss of binding, within the Pistop® groove of the reported clathrin mutant invalidating recent assumptions of poor selectivity for this family of clathrin inhibitors.

  20. Synthesis, anti-microbial and molecular docking studies of quinazolin-4(3H)-one derivatives.

    Science.gov (United States)

    Mabkhot, Yahia Nasser; Al-Har, Munirah S; Barakat, Assem; Aldawsari, Fahad D; Aldalbahi, Ali; Ul-Haq, Zaheer

    2014-06-25

    In this work, synthesis, antimicrobial activities and molecular docking studies of some new series of substituted quinazolinone 2a-h and 3a-d were described. Starting form 2-aminobenzamide derivatives 1, a new series of quinazolinone derivatives has been synthesized, in high yields, assisted by microwave and classical methods. Some of these substituted quinazolinones were tested for their antimicrobial activity against Gram-negative bacteria (Pseudomonas aeruginosa and Esherichia coli) and Gram-positive bacteria (Staphylococcus aureus, and Bacillus subtilis), and anti-fungal activity against (Aspergillus fumigatus, Saccharomyces cervevisiae, and Candida albicans) using agar well diffusion method. Among the prepared products, 3-benzyl-2-(4-chlorophenyl)quinazolin-4(3H)-one (3a) was found to exhibits the most potent in vitro anti-microbial activity with MICs of 25.6±0.5, 24.3±0.4, 30.1±0.6, and 25.1±0.5 µg/mL against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Esherichia coli, respectively. Compound 3a was found to exhibits the most potent in vitro anti-fungal activity with MICs of 18.3±0.6, 23.1±0.4, and 26.1±0.5 µg/mL against Aspergillus fumigatus, Saccharomyces cervevisiae, and Candidaal bicans, respectively.

  1. Synthesis, Anti-microbial and Molecular Docking Studies of Quinazolin-4(3H-one Derivatives

    Directory of Open Access Journals (Sweden)

    Yahia Nasser Mabkhot

    2014-06-01

    Full Text Available In this work, synthesis, antimicrobial activities and molecular docking studies of some new series of substituted quinazolinone 2a–h and 3a–d were described. Starting form 2-aminobenzamide derivatives 1, a new series of quinazolinone derivatives has been synthesized, in high yields, assisted by microwave and classical methods. Some of these substituted quinazolinones were tested for their antimicrobial activity against Gram-negative bacteria (Pseudomonas aeruginosa and Esherichia coli and Gram-positive bacteria (Staphylococcus aureus, and Bacillus subtilis, and anti-fungal activity against (Aspergillus fumigatus, Saccharomyces cervevisiae, and Candida albicans using agar well diffusion method. Among the prepared products, 3-benzyl-2-(4-chlorophenylquinazolin-4(3H-one (3a was found to exhibits the most potent in vitro anti-microbial activity with MICs of 25.6 ± 0.5, 24.3 ± 0.4, 30.1 ± 0.6, and 25.1 ± 0.5 µg/mL against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Esherichia coli, respectively. Compound 3a was found to exhibits the most potent in vitro anti-fungal activity with MICs of 18.3 ± 0.6, 23.1 ± 0.4, and 26.1 ± 0. 5 µg/mL against Aspergillus fumigatus, Saccharomyces cervevisiae, and Candidaal bicans, respectively.

  2. Border Crossings: A Commentary on Henkjan Honing's "On the Growing Role of Observation, Formalization and Experimental Method in Musicology"

    Directory of Open Access Journals (Sweden)

    Nicholas Cook

    2006-09-01

    Full Text Available In the early twentieth century systematic musicology, which was based on the comparative method, played a prominent role in the discipline: however it was appropriated by the Nazis and fell out of favour after the war. It was replaced by ethnomusicology and structuralist music theory, both of which emphasized the individual context (cultural or structural and eschewed comparison between contexts. Both also developed an epistemology based on the generation of meaning through the act of "experiencing and understanding music" (Titon 1997: 87: this epistemology, characteristic of cultural musicology and theory (CMT in general, is quite distinct from that of the cognitive sciences of music (CSM. The otherwise confusing variety of musicological practices subsumed under the category "systematic musicology", as set out in Honing's article on which this is a commentary, can be usefully seen in terms of two distinct dimensions, those of method and of epistemology. It follows from this that empirical methods are as consistent with, and as potentially valuable to, CMT as they are to CSM, and that EMR has the potential to reach both constituencies.

  3. Extensional extrusion: Insights into south-eastward expansion of Tibetan Plateau from magnetotelluric array data

    Science.gov (United States)

    Dong, Hao; Wei, Wenbo; Jin, Sheng; Ye, Gaofeng; Zhang, Letian; Jing, Jian'en; Yin, Yaotian; Xie, Chengliang; Jones, Alan G.

    2016-11-01

    Despite extensive effort over many decades to understand the tectonic evolution of the Tibetan Plateau, the geodynamic processes creating the iconic south-eastward expansion of the plateau at the Eastern Himalayan Syntaxis (EHS) are still unclear and are hotly debated. Two popular (but not necessarily exclusive) geodynamic models, namely crustal flow at mid-to-lower crustal depths and coherent deformation between the crust and lithospheric mantle, are commonly invoked to explain the expansion mechanism. However, neither of these is able to reconcile all of the abundant geological and geophysical data. Here we present a three-dimensional (3D) geo-electrical model, derived from new SINOPROBE magnetotelluric (MT) array data, that reveals the geo-electrical, and by inference rheological, structure of southeast Tibet. Instead of NW-SE conductive channels proposed in prior two-dimensional (2D) MT studies, distinct NNE-SSW directed quasi-linear conductive anomalies are identified in the mid-to-lower crust, which are separated by a large-scale electrically resistive structure that extends from the crust to the upper mantle. This argues against the prior proposed model of south-eastward conductive anomalies, and hence against the southeast lower crust flow of material. To interpret our observations and resultant model, a new mechanism of "extensional extrusion" is proposed to address the lithospheric deformation of the south-eastward expansion of Tibetan Plateau.

  4. Thermal and geodynamic contributions to the elevation of the Altiplano-Puna plateau

    Science.gov (United States)

    Prezzi, Claudia; Iglesia Llanos, María Paula; Götze, Hans-Jürgen; Schmidt, Sabine

    2014-12-01

    The most remarkable feature of the Central Andes is the Altiplano-Puna plateau. This plateau is characterized by 3.5 km average elevation, approximately 70 km crustal thickness and very high heat flow. The upper mantle structure changes along strike below the plateau. The upper mantle below the Puna becomes hotter, and the lithosphere becomes thinner and weaker. These features suggest that thermal isostasy could play a role in the compensation of the Altiplano-Puna. Thermal isostasy is the geodynamic process whereby regional variations in the lithospheric thermal regime cause changes in elevation. Elevation changes result from variations in rock density in response to thermal expansion. The aim of this study is to estimate the thermal and geodynamic contributions to the elevation. While the thermal component of the Altiplano elevation would be of 1 km, the thermal contribution to the southern Puna elevation would be of 1.5 km. However, in the case of the southern Puna a portion of the actual topography (∼20%) cannot be explained considering only compositional and thermal effects, suggesting additional geodynamical support. The obtained results suggest that the thermal state of the lithosphere would play a significant role in the elevation of the Central Andes, and may be responsible of some of the geological differences displayed by the Altiplano and the Puna.

  5. Revisiting Asian monsoon formation and change associated with Tibetan Plateau forcing: I. Formation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guoxiong; Liu, Yimin; Duan, Anmin; Bao, Qing [Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China); Dong, Buwen [University of Reading, Department of Meteorology, National Centre for Atmospheric Science, Reading (United Kingdom); Liang, Xiaoyun [China Meteorological Administration, National Climate Center, Beijing (China); Yu, Jingjing [China Meteorological Administration, National Meteorological Information Center, Beijing (China)

    2012-09-15

    Numerical experiments with different idealized land and mountain distributions are carried out to study the formation of the Asian monsoon and related coupling processes. Results demonstrate that when there is only extratropical continent located between 0 and 120 E and between 20/30 N and the North Pole, a rather weak monsoon rainband appears along the southern border of the continent, coexisting with an intense intertropical convergence zone (ITCZ). The continuous ITCZ surrounds the whole globe, prohibits the development of near-surface cross-equatorial flow, and collects water vapor from tropical oceans, resulting in very weak monsoon rainfall. When tropical lands are integrated, the ITCZ over the longitude domain where the extratropical continent exists disappears as a consequence of the development of a strong surface cross-equatorial flow from the winter hemisphere to the summer hemisphere. In addition, an intense interaction between the two hemispheres develops, tropical water vapor is transported to the subtropics by the enhanced poleward flow, and a prototype of the Asian monsoon appears. The Tibetan Plateau acts to enhance the coupling between the lower and upper tropospheric circulations and between the subtropical and tropical monsoon circulations, resulting in an intensification of the East Asian summer monsoon and a weakening of the South Asian summer monsoon. Linking the Iranian Plateau to the Tibetan Plateau substantially reduces the precipitation over Africa and increases the precipitation over the Arabian Sea and the northern Indian subcontinent, effectively contributing to the development of the South Asian summer monsoon. (orig.)

  6. Constraining the stepwise migration of the eastern Tibetan Plateau margin by apatite fission track thermochronology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Granites sampled from Garzê-Litang thrust, Longmen Shan thrust, Garzê and Litang strike-slip faults in the eastern Tibetan Plateau have been analyzed with apatite fission track thermochronological method in this study. The measured fission track apparent ages, combined with the simulated annealing mod- eling of the thermal history, have been used to reconstruct the thermal evolutionary histories of the samples and interpret the active history of the thrusts and faults in these areas. Thermal history mod- eling shows that earlier tectonic cooling occurred in the Garzê-Litang thrust in Miocene (~20―16 Ma) whereas the later cooling occurred mainly in the Longmen Shan thrust since ~5 Ma. Our study sug- gests that the margin of eastern Tibetan Plateau was extended by stages: through strike-slip faults deformations and related thrusts, the upper crust formed the Garzê-Litang margin in the Miocene epoch and then moved to the Longmen Shan margin since ~5 Ma. During this process, the deformations of different phases in the eastern Tibetan Plateau were absorbed by the thrusts within them and conse- quently the tectonic events of long-distance slip and extrusion up to hundreds of kilometers have not been found.

  7. Cenozoic pulsed deformation history of northeastern Tibetan Plateau reconstructed from fission-track thermochronology

    Science.gov (United States)

    Wang, Xiuxi; Song, Chunhui; Zattin, Massimiliano; He, Pengju; Song, Ai; Li, Jijun; Wang, Qiangqiang

    2016-03-01

    The synorogenic basin deposits and bedrocks of their source terranes within and along the Tibetan Plateau contain fundamental information regarding the spatiotemporal evolution of the largest orogenic plateau on Earth. The Guide-Xining region is located on the northeastern portion of the Tibet and its Eocene-early Pleistocene basin succession is well preserved. By integrating apatite fission-track thermochronology from sedimentary and basement samples, with heavy minerals and paleocurrent data, we decipher an almost complete sequence of exhumation and depositional events during the Cenozoic. Our data indicates that the initial deformation along the Guide-Xining region occurred since the Eocene, with the reorganization of the regional tectonomorphology and the formation of a broad basin. Thereafter, this single large basin was disrupted by multiple episodes of exhumation and deformation. Our study illuminate that the multiple-stage active processes (occurred at 49-42, 36-32, 23-19, 16-13 and 8-4 Ma) work together to produce the current NE Tibetan Plateau.

  8. Constraining the stepwise migration of the eastern Tibetan Plateau margin by apatite fission track thermochronology

    Institute of Scientific and Technical Information of China (English)

    LAI QingZhou; DING Lin; WANG HongWei; YUE YaHui; CAI FuLong

    2007-01-01

    Granites sampled from Garzê-Litang thrust, Longmen Shan thrust, Garzê and Litang strike-slip faults in the eastern Tibetan Plateau have been analyzed with apatite fission track thermochronological method in this study. The measured fission track apparent ages, combined with the simulated annealing modeling of the thermal history, have been used to reconstruct the thermal evolutionary histories of the samples and interpret the active history of the thrusts and faults in these areas. Thermal history modeling shows that earlier tectonic cooling occurred in the Garzê-Litang thrust in Miocene (~20―16 Ma) whereas the later cooling occurred mainly in the Longmen Shan thrust since ~5 Ma. Our study suggests that the margin of eastern Tibetan Plateau was extended by stages: through strike-slip faults deformations and related thrusts, the upper crust formed the Garzê-Litang margin in the Miocene epoch and then moved to the Longmen Shan margin since ~5 Ma. During this process, the deformations of different phases in the eastern Tibetan Plateau were absorbed by the thrusts within them and consequently the tectonic events of long-distance slip and extrusion up to hundreds of kilometers have not been found.

  9. Seasonal response of grasslands to climate change on the Tibetan Plateau.

    Science.gov (United States)

    Yu, Haiying; Xu, Jianchu; Okuto, Erick; Luedeling, Eike

    2012-01-01

    Monitoring vegetation dynamics and their responses to climate change has been the subject of considerable research. This paper aims to detect change trends in grassland activity on the Tibetan Plateau between 1982 and 2006 and relate these to changes in climate. Grassland activity was analyzed by evaluating remotely sensed Normalized Difference Vegetation Index (NDVI) data collected at 15-day intervals between 1982 and 2006. The timings of vegetation stages (start of green-up, beginning of the growing season, plant maturity, start of senescence and end of the growing season) were assessed using the NDVI ratio method. Mean NDVI values were determined for major vegetation stages (green-up, fast growth, maturity and senescence). All vegetation variables were linked with datasets of monthly temperature and precipitation, and correlations between variables were established using Partial Least Squares regression. Most parts of the Tibetan Plateau showed significantly increasing temperatures, as well as clear advances in late season phenological stages by several weeks. Rainfall trends and significant long-term changes in early season phenology occurred on small parts of the plateau. Vegetation activity increased significantly for all vegetation stages. Most of these changes were related to increasing temperatures during the growing season and in some cases during the previous winter. Precipitation effects appeared less pronounced. Warming thus appears to have shortened the growing season, while increasing vegetation activity. Shortening of the growing season despite a longer thermally favorable period implies that vegetation on the Tibetan Plateau is unable to exploit additional thermal resources availed by climate change. Ecosystem composition may no longer be well attuned to the local temperature regime, which has changed rapidly over the past three decades. This apparent lag of the vegetation assemblage behind changes in climate should be taken into account when

  10. Dust provenance change of Chinese Loess Plateau during the past 7Ma

    Science.gov (United States)

    Zhang, Hanzhi

    2017-04-01

    Aeolian deposit (e.g. loess, paleo-soil and Red Clay) in Chinese Loess Plateau is one of the most valuable climate archives on land in late Cenozoic. Surveying the origin of these aeolian sediments is essential for the interpretation of the climate proxies potentially over the past 25Ma. However, disputes still exist on whether or not there is shift of dust origin in tectonic time scale or glacial-interglacial time scale. Detrital zircon dating method is applied on aeolian sediments of Lantian site in south part of Chinese Loess Plateau, which is at the foot of Qinling Mountain in order to reveal the provenance evolution during the past 7Ma. The results indicate that the composition of aeolian sediments shifted at around 2.6 Ma. Detrital zircon age reveals that the tertiary Red Clay is mainly derived from the North Tibet Plateau and Qinling Mountain. This indicates that the origin area for the tertiary Red Clay is relative local. Quaternary Loess of this site is basically mixture of sediments from North Tibet Plateau and Gobi Altay Mountains. The composition of local sediments from Qinling Mountains is relatively low. Sediment in L1 layer contains the highest proportions of Gobi Altay Mountains material, which show completely different pattern from other loess sediments. Besides this, there are no consistent composition shifts between glacial and interglacial periods. The time of dust origin shift is in coincident with initiation of the Northern Hemisphere ice sheet. This suggests that the onset of the Northern Hemisphere ice sheet enhanced the surface erosion of the area of Gobi Altay Mountains. This process contributed more detrital material to be blown to the air. Furthermore, enhanced winter monsoon played an important role in the transportation of dust material. However, the reason for the unique characteristics of loess in L1 is not clear.

  11. Eocene Tibetan Plateau remnants preserved in the Northwest Himalaya

    Science.gov (United States)

    van der Beek, P. A.; van Melle, J.; Guillot, S.; Pêcher, A.; Reiners, P. W.; Nicolescu, S.; Latif, M.

    2009-04-01

    The northwest Himalaya shows strongly contrasting relief, opposing deeply incised mountain ranges characterized by extremely rapid exhumation and some of the highest peaks in the world (i.e., the Karakorum range and Nanga Parbat massif) to high-elevation, low-relief areas such as the 4000-m high Deosai plateau in northern Pakistan and the 5000-m high Tso Morari in Indian Ladakh. The origin and evolution of such plateau regions in the syntaxis of the most active continental collision in the world remain elusive. Here, we report the first low-temperature thermochronology (apatite fission-track, apatite and zircon (U-Th)/He) data from the Deosai plateau and use thermal history modelling to show that it has undergone continuous slow (≤ 200 m/Myr) denudation and has thus remained tectonically stable for the last 35 Myr at least. The inferred history of constant slow denudation of the plateau contradicts the hypothesis that widespread low-relief surfaces in the northwest Himalaya result from efficient, km-scale glacial erosion during Quaternary times; such erosion would have been recorded as a phase of rapid recent denudation that is not observed in the data. Slow continuous denudation since Eocene times, i.e. only 15-20 Myr after the onset of India-Asia collision implies that the Deosai plateau surface developed early in the Himalayan history and limits the phase of orogenic relief growth in the Ladakh-Kohistan arc to the early Paleogene. Although thermochronology data do not directly record surface uplift, the simplest explanation for the inferred constant denudation rates is that the plateau had reached its present-day elevation already during the Eocene, as a later phase of surface uplift would have triggered an erosional response that would have been recorded by the thermochronology data. We use morphological analyses to characterise such plateaux and identify them at the scale of the entire northwest Himalaya and compare our thermochronological data with

  12. 基于参考模型的珩磨机往复位置自适应控制%Honing machines reciprocating motion position adaptive control based on reference mode

    Institute of Scientific and Technical Information of China (English)

    周耿烈; 胡赤兵; 陈杉杉; 赵家黎

    2012-01-01

    On the basis of brief introduction to the processing of honing machine reciprocating movement , its malh-ematic model and the system of reference model were established,and then the control system was conducted hy using the tool of MATLAB. The simulation result showed that the response characteristics of the dynamic performance can keep a consistent with the adaptive control by the way of model reference adaptive control, and overshoots are reduced which can well satisfied the system performance index, and has a certain anti-interference ability.%通过简要介绍珩磨加工的基础上,建立其往复运动数学模型及其参考模型系统,然后利用MATLAB工具对控制系统进行仿真分析.结果表明采用参考模型自适应控制方法能够使珩磨头往复换向位置与参考模型一致,同时超调量也有所减小,能够很好地满足控制系统的性能指标,并具有一定的抗干扰能力.

  13. The Development in modeling Tibetan Plateau Land/Climate Interaction

    Science.gov (United States)

    Xue, Yongkang; Liu, Ye; li, qian; Maheswor Shrestha, Maheswor; Ma, Hsi-Yen; Cox, Peter; Sun, shufen; Koike, Toshio

    2015-04-01

    Tibetan Plateau (TP) plays an important role in influencing the continental and planetary scale climate, including East Asian and South Asian monsoon, circulation and precipitation over West Pacific and Indian Oceans. The numerical study has identified TP as the area with strongest land/atmosphere interactions over the midlatitude land. The land degradation there has also affected the monsoon precipitation in TP along the monsoon pathway. The water cycle there affects water sources for major Asian river systems, which include the Tarim, Amu Darya, Indus, Ganges, Brahmaputra, Irrawaddy, Salween, Mekong, Yellow, and Yangtze Rivers. Despite the importance of TP land process in the climate system, the TP land surface processes are poorly modeled due to lack of data available for model validation. To better understand, simulate, and project the role of Tibetan Plateau land surface processes, better parameterization of the Tibetan Land surface processes have been developed and evaluated. The recently available field measurement there and satellite observation have greatly helped this development. This paper presents these new developments and preliminary results using the newly developed biophysical/dynamic vegetation model, frozen soil model, and glacier model. In recent CMIP5 simulation, the CMIP5 models with dynamic vegetation model show poor performance in simulating the TP vegetation and climate. To better simulate the TP vegetation condition and its interaction with climate, we have developed biophysical/dynamic vegetation model, the Simplified Simple Biosphere Model version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics Model (SSiB4/TRIFFID), based on water, carbon, and energy balance. The simulated vegetation variables are updates, driven by carbon assimilation, allocation, and accumulation, as well as competition between plant functional types. The model has been validated with the station data, including those measured over the TP

  14. Aftershock Decay Rates in the Iranian Plateau

    Science.gov (United States)

    Ommi, S.; Zafarani, H.; Zare, M.

    2016-07-01

    Motivated by the desire to have more information following the occurrence of damaging events, the main purpose of this article is to study aftershock sequence parameters in the Iranian plateau. To this end, the catalogue of the Iranian earthquakes between 2002 to the end of 2013 has been collected and homogenized among which 15 earthquakes have been selected to study their aftershock decay rates. For different tectonic provinces, the completeness magnitudes ( M c) of the earthquake catalogue have been calculated in different time intervals. Also, the M c variability in spatial and temporal windows has been determined for each selected event. For major Iranian earthquakes, catalogue of aftershocks has been collected thanks to three declustering methods: first, the classical windowing method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974); second, a modified version of this using spatial windowing based on the Wells and Coppersmith (Bull Seismol Soc Am 84:974-1002, 1994) relations; and third, the Burkhard and Grünthal (Swiss J Geosci 102:149-188, 2009) scheme. Effects of the temporal windows also have been investigated using the time periods of 1 month, 100 days, and 1 year in the declustering method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). In the next step, the modified Omori law coefficients have been calculated for the 15 selected earthquakes. The calibrated regional generic model describing the temporal and magnitude distribution of aftershocks is of interest for time-dependent seismic hazard forecasts. The regional characteristics of the aftershock decay rates have been studied for the selected Iranian earthquakes in the Alborz, Zagros and Central Iran regions considering their different seismotectonics regimes. However, due to the lack of sufficient data, no results have been reported for the Kopeh-Dagh and Makran seismotectonic regions.

  15. Comparison of hole surface finishing processes with roller burnishing method applied in copper materials

    OpenAIRE

    Adnan AKKURT; Kurt, Abdullah; Ahmet ÖZDEMİR; ŞEKER, Ulvi

    2014-01-01

    Surface finishing processes such as drilling, turning, reaming, grinding, honing and roller burnishing etc. are widely used in manufacturing as hole surface finishing process. In addition to the characteristics of hole such as the surface roughness, the surface hardness and the wear resistance, the circularity and cylindricality of hole are also effective on the performance of hole. In this paper, it is presented that different hole surface finishing processes were applied to the samples made...

  16. Amplitude of climatic changes in Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    On the basis of ice core and meteorological data from the Qinghai-Tibetan (Q-T) Plateau, this article focuses on the discussion of the problems related to the sensitivity of temporal and spatial changes of the climate in high-altitude regions, particularly in the Q-T Plateau. The features of abrupt climatic changes of the past 100 ka, 2 000 a and recent years indicate that the amplitude of these changes in the Q-T Plateau was obviously larger than that in low-altitude regions. The scope of temperature change above 6 000 m in the Q-T Plateau between glacial and interglacial stages could reach over 10℃, but only about 4℃ in low-elevation regions close to sea level. During the last 2 000 a, the amplitude of temperature changes at Guliya (over 6 000 m a.s.l.) in the Q-T Plateau reached 7℃, in comparison with 2℃ in eastern China at low altitude. In the present age, apparent differences of climatic warming have been observed in the Q-T Plateau, indicating that the warming in high-elevation regions is much higher than that in low-elevation regions. The temperature in over 3 500 m regions of the Q-T Plateau have been increasing at a rate of 0.25×10-1/a in recent 30 years, but almost no change has taken place in the regions below 500 m. Thus, we concluded that high-altitude regions are more sensitive to climatic changes than the low-altitude regions.

  17. The Colorado Plateau II: biophysical, socioeconomic, and cultural research

    Science.gov (United States)

    Mattson, David J.; van Riper, Charles

    2005-01-01

    The publication of The Colorado Plateau: Cultural, Biological, and Physical Research in 2004 marked a timely summation of current research in the Four Corners states. This new volume, derived from the seventh Biennial Conference on the Colorado Plateau in 2003, complements the previous book by focusing on the integration of science into resource management issues. The 32 chapters range in content from measuring human impacts on cultural resources, through grazing and the wildland-urban interface issues, to parameters of climate change on the Plateau. The book also introduces economic perspectives by considering shifting patterns and regional disparities in the Colorado Plateau economy. A series of chapters on mountain lions explores the human-wildland interface. These chapters deal with the entire spectrum of challenges associated with managing this large mammal species in Arizona and on the Colorado Plateau, conveying a wealth of timely information of interest to wildlife managers and enthusiasts. Another provocative set of chapters on biophysical resources explores the management of forest restoration, from the micro scale all the way up to large-scale GIS analyses of ponderosa pine ecosystems on the Colorado Plateau. Given recent concerns for forest health in the wake of fires, severe drought, and bark-beetle infestation, these chapters will prove enlightening for forest service, park service, and land management professionals at both the federal and state level, as well as general readers interested in how forest management practices will ultimately affect their recreation activities. With broad coverage that touches on topics as diverse as movement patterns of rattlesnakes, calculating watersheds, and rescuing looted rockshelters, this volume stands as a compendium of cutting-edge research on the Colorado Plateau that offers a wealth of insights for many scholars.

  18. The age of the lithospheric mantle beneath the Northern Kerguelen Plateau

    Science.gov (United States)

    Debaille, V.; Mattielli, N. D.; Weis, D. A.

    2009-12-01

    geochemically distinct younger lavas (<10 Myr) [3], and show no implication of continental lithosphere beneath the Northern Kerguelen Plateau. These results are consistent with mixture of enriched plume material and depleted mantle horizontally migrating in sublithospheric channels from the ridge to the archipelago, though this process likely progressively vanished at ~26 Myr ago [4]. The internal Sm-Nd and Lu-Hf isochrons that will be obtained on the basic and ultrabasic xenoliths should provide important information about the age and the nature of the lithospheric mantle beneath the Northern Kerguelen Plateau, in a plume-ridge interaction context. [1] Hassler, D. and Shimizu, N. (1998), Science 28, 418-420 [2] Gregoire, M. et al. (1998), Contrib. Mineral. Petrol. 133, 259-283 [3] Mattielli, N. et al. (2002), J. Petrol. 43, 1327-1339 [4] Doucet, S. et al. (2002), J. Petrol. 43, 1341-1366

  19. Synthesis of 2-substituted 9-oxa-guanines {5-aminooxazolo[5,4-d]pyrimidin-7(6H-ones} and 9-oxa-2-thio-xanthines {5-mercaptooxazolo[5,4-d]pyrimidin-7(6H-ones}

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available Oxazolo[5,4-d]pyrimidines can be considered as 9-oxa-purine analogs of naturally occurring nucleic acid bases. Interest in this ring system has increased due to recent reports of biologically active derivatives. In particular, 5-aminooxazolo[5,4-d]pyrimidine-7(6H-ones (9-oxa-guanines have been shown to inhibit ricin. The preparation of a series of 2-substituted 5-aminooxazolo[5,4-d]pyrimidin-7(6H-ones and related 5-thio-oxazolo[5,4-d]pyrimidines is described, including analogs suitable for further elaboration employing “click” chemistry utilizing copper-catalyzed Huisgen 1,3-dipolar cycloadditions. Two of the compounds prepared were found to inhibit ricin with IC50 ca. 1–3 mM.

  20. Gravitational salt tectonics above a rising basement plateau offshore Algeria

    Science.gov (United States)

    Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël

    2017-04-01

    Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from

  1. Seismic wave speed structure of the Ontong Java Plateau

    Science.gov (United States)

    Covellone, Brian M.; Savage, Brian; Shen, Yang

    2015-06-01

    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution image to date of the wave speed structure of the OJP region. We use a data set that combines Rayleigh waves extracted from both ambient noise and earthquake waveforms and an iterative finite-frequency tomography methodology. The combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and 300 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly that resulted from the residuum of eclogite entrainment during the plateau's formation. The combination of our imaged wave speed structure and previous geochemical work suggest that a surfacing plume head entrained eclogite from the deep mantle and accounts for the anomalous buoyancy characteristics of the plateau and observed fast wave speeds.

  2. Spontaneous collapse of the tibial plateau: radiological staging

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero, P.; Leon, F.; Zafra, M. [University Hospital ' ' Reina Sofia' ' , Orthopaedic Department, Cordoba (Spain); Montero, R.; Carreto, A. [University Hospital ' ' Reina Sofia' ' , Radiology Department, Cordoba (Spain)

    2005-07-01

    This paper proposes a radiological staging system for necrosis of the tibial plateau, similar to those already developed for the hip and the medial femoral condyle. We retrospectively studied the clinical case histories and radiographic findings of 14 patients (15 affected knees) with histologically proven osteonecrosis of the tibial plateau. Stage I was marked by normal radiograph, but increased uptake in bone scan and subchondral areas of abnormal marrow signal intensity in magnetic resonance imaging (MRI), as reported in other osteonecrosis sites. Stage II was characterised by cystic and sclerotic changes, and stage III fracture of the medial rim of the medial tibial plateau and tibial plateau collapse were present. Stage IV was marked by joint narrowing. These changes appeared earlier and were more pronounced when there was genu varum/valgum or involvement of the lateral tibial plateau. The radiological evolution of the disease appears to follow a four-stage course over a period of roughly one year from the onset of symptoms. (orig.)

  3. Verçenik Plateau Alternative Tourism and Recreational Activities

    Directory of Open Access Journals (Sweden)

    İzzet İSLAMOĞLU

    2014-08-01

    Full Text Available In the last century working life become easier and result of this increased people free time, after that interest of tourism activities wide spread all over. Plateau tourism or highland places are not first choices of the tourism activities but plateau rec reation will give an application for potential activity place. Turkey have unmatched nature and rich environmental resources will able to give any kind of tourism activities. In that context city of Rize took place in Black Sea region with different capabi lities, one of the source areas that make up tourism and recreational activities. This research intended for Vercenik Plateau take place 60 km away from Camlihemsin district center and will determine potential tourism and recreational application. Research is based on field observation and studies. This information obtained as a result ofthis evaluationbeing associated toliterature data and that information determined which exercise can be done in the field. Vercenik Plateau; with pristine environment and ru ral locations, the fresh water supplies, unique flora for city of Rize has high recreational capacities.As a result of study; Vercenik Plateau has natural features with the great potential of the alternative tourism as it is suitable for areas but not asse ss enough potential tourism and recreational activities without prior review has been observed.

  4. Rapid Loss of Lakes on the Mongolian Plateau

    Science.gov (United States)

    Tao, S.; Fang, J.; Zhao, X.; Zhao, S.; Shen, H.; Hu, H.; Tang, Z.; Wang, Z.; Guo, Q.

    2015-12-01

    Lakes are widely distributed on the Mongolian Plateau and as critical water sources have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multi-temporal Landsat images from the 1970s to 2000s, combining with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, while in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

  5. 功率超声珩磨加工振动的研究与控制%Research and Monitoring to Vibration of Power Ultrasonic Honing

    Institute of Scientific and Technical Information of China (English)

    邢秀琴; 高春强; 祝锡晶

    2013-01-01

    This paper Provides the solution that makes the amplitude of ultrasonic honing keeping near the maximum, aiming at the problem of amplitude decaying with the change of external conditions. Using Hall sensor MLX9025, the current of transducer is maasured and also design the relevant circuit is designed. According to the current, the output power of ultrasonic generator is adjusted, and the whole system in a resonant state is ensured. Thus, the amplitude of the oil-stone keeps near the biggest amplitude. Finally, the scheme is applied to MBA4215 semi - automatic and vertical ultrasonic honing machine, and through the fairly good honing resuit, its feasibility is proved.%针对超声珩磨加工中系统振幅随外界条件的变化而衰减的问题,提出了维持超声珩磨加工的振幅在最大值附近的方案.采用霍尔传感器MLX90251检测输入换能器的电流,并设计了相关的电路.根据电流的变化调节超声发生器的输出功率,进而使整个系统处于谐振状态,即油石的振幅保持在最大振幅附近.最后,将此方案应用于MBA4215型半自动立式珩磨机的功率超声加工中,根据加工的良好效果证明此方案可行.

  6. Emplacement Scenarios for Vallis Schroteri, Aristarchus Plateau, the Moon

    Science.gov (United States)

    Garry, W. Brent; Bleacher, Jacob E.

    2011-01-01

    The volcanic processes that formed Vallis Schr teri are not well understood. Vallis Schr teri, located on the Aristarchus Plateau, is the largest rille on the Moon, and it displays three key morphologic components: the Cobra Head, the 155-km-long primary rille, and the 240-km-long inner rille. Observations of terrestrial eruptions are applied here to help explain the morphologic relationships observed for Vallis Schr teri. The Cobra Head, a 10-km-wide source vent surrounded by a 35-kmdiameter and 900-m-high low shield, might have been constructed from fl ows, spatter, and pyroclastic deposits erupted during lava fountain events, similar to the early stages of the vent at Pu u O o in Hawaii and the fi nal morphology of Bandera crater, a cinder cone in New Mexico. The vent fed an initial sheet fl ow controlled by preeruption topography. A channel formed within this sheet fl ow was the foundation for the primary rille, which deepened through construction and thermomechanical erosion by lava. The inner rille is confi ned to the fl at fl oor of the primary rille and is characterized by tight gooseneck meanders. This rille crosscuts the distal scarp of the primary rille and extends toward Oceanus Procellarum. This enigmatic relationship can be explained through backup, overfl ow, and diversion of the lava into a new rille that eroded into the margin of the primary rille. Similar backup, overfl ow, and redirection of the lava fl ow were observed during the 1984 Mauna Loa eruption in Hawaii. Analysis of the fi nal morphology of lunar rilles provides key information about lunar volcanic processes and insight into the local stratigraphy.

  7. Fraturas do planalto tibial Tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Maurício Kfuri Júnior

    2009-01-01

    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  8. Synthesis, characterization and antibacterial activities of Zn(II and Cd(II complexes of a quinazoline-4(3H-one Schiff base

    Directory of Open Access Journals (Sweden)

    Brahman Dhiraj

    2014-01-01

    Full Text Available Zn(II and Cd(II complexes of a Schiff base derived from quinazoline-4(3H one and 2-formylphenoxy acetic acid were prepared and characterized by elemental and different spectroscopic (IR, UV-Visible and NMR analyses. The elemental analysis indicated the formation of the complexes: [ML(AcO].H2O, where M stands for Zn(II and Cd(II and L stands for quinazoline-4(3H-one Schiff base. The molar conductivities of the prepared complexes revealed their non-electrolytic nature. The complexes were also investigated for their antimicrobial activities by using turbidometric assay method.

  9. A facile synthesis and fungicidal activities of 2-(alkylamino-5,6-dimethylthieno[2,3-d]pyrimidin-4(3H-ones

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available The aza-Wittig reactions of iminophosphorane 3 with aromatic isocyanates generated carbodiimides 4, which were reacted with alkylamines under mild conditions to give a series of 2-(alkylamino-5,6-dimethylthieno[2,3-d]pyrimidin-4(3H-ones 6 and 8 in satisfactory yield. Their structures were confirmed by 1H NMR, EI-MS, IR and elementary analysis, and compound 8c was further analyzed by single-crystal X-ray diffraction. The preliminary bioassays indicated that these compounds showed excellent fungicidal activities against six kinds of fungi.

  10. New Efficient Synthesis of 3,4-Dihydropyrimidin-2(1H-ones Catalyzed by Benzotriazolium-Based Ionic Liquids under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Zhiqing Liu

    2016-04-01

    Full Text Available An efficient synthesis of novel 3,4-dihydropyrimidin-2(1H-ones (DHPMs and their derivatives, using Brønsted acidic ionic liquid [C2O2BBTA][TFA] as a catalyst, from the condensation of aryl aldehyde, β-ketoester and urea was described. Reactions proceeded smoothly for 40 min under solvent-free conditions and gave the desirable products with good to excellent yields (up to 99%. The catalyst could be easily recycled and reused with similar efficacies for at least six cycles.

  11. Synthesis and in vitro cytotoxic evaluation of 2-hydrazinylpyrido[2,3-6]pyrazin-3(4H)-one derivatives

    Institute of Scientific and Technical Information of China (English)

    Guo Gang Zhang; Ya Jing Liu; Xiao Guang Ma; Hao Dong; Ju Li; Ping Gong

    2011-01-01

    A series of novel 2-hydrazinylpyrido[2,3-b]pyrazin-3(4H)-one derivatives were synthesized and evaluated for their cytotoxic activities against A549, MDA-MB-231 and HT-29 cell lines in vitro. Pharmacological data indicated that compounds 5b, 5c, 10a and 10g possessed marked cytotoxicity, especially 10a (with IC50 values of 0.81, 2.56 and 1.63 μmol/L against A549, MDA-MB-231 and HT29 cell lines, respectively), which had emerged as a lead compound.

  12. One-pot three-component synthesis of pyrano [3,2-b]pyrazolo[4,3-e]pyridin-8(1H)-ones.

    Science.gov (United States)

    Safaei, Shirin; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad Reza; Moghadam, Majid; Tangestaninejad, Shahram; Mirkhani, Valiollah; Khavasi, Hamid Reza

    2013-03-11

    An efficient one-pot synthesis of novel pyrano[3,2-b]pyrazolo[4,3-e]pyridin-8(1H)-ones via three-component condensation of kojic acid, 1-H-pyrazol-5-amines and aldehydes in the presence of a catalytic amount of Zn(OTf)(2) followed by H(2)O(2)-mediated oxidation is reported. Furthermore, the synthesis of 1'H-spiro[indoline-3,4'-pyrano[2,3-b]pyrazolo[3,4-e]pyridine]-2,8'(9'H)-diones were chosen for the library validation.

  13. Zero temperature non-plateau magnetization and magnetocaloric effect in an Ising-XYZ diamond chain structure

    Science.gov (United States)

    Torrico, J.; Rojas, M.; de Souza, S. M.; Rojas, Onofre

    2016-10-01

    Zero temperature non-plateau magnetization is a peculiar property of a quantum spin chain and it sometimes appears due to different gyromagnetic factors. In this study, we illustrate a quite unusual non-plateau magnetization property driven by XY-anisotropy in an Ising-XYZ diamond chain. Two particles with spin-1/2 are bonded by XYZ coupling and they are responsible for the emergence of non-plateau magnetization. These two quantum operator spins are bonded to two nodal Ising spins and this process is repeated infinitely to yield a diamond chain structure. Due to the non-plateau magnetization property, we focus our discussion on the magnetocaloric effect of this model by presenting the isentropic curves and the Grüneisen parameters, as well as showing the regions where the model exhibits an efficient magnetocaloric effect. Due to the existence of two phases located very close to each other, the strong XY-anisotropy exhibits a particular behavior with a magnetocaloric effect, with a wider interval in the magnetic field, where the magnetocaloric effect is efficient.

  14. Quantitative Assessment of Desertification Using Landsat Data on a Regional Scale – A Case Study in the Ordos Plateau, China

    Directory of Open Access Journals (Sweden)

    Jianjun Pan

    2009-03-01

    Full Text Available Desertification is a serious threat to the ecological environment and social economy in our world and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. In this paper, the Ordos Plateau in China was selected as the research region and a quantitative method for desertification assessment was developed by using Landsat MSS and TM/ETM+ data on a regional scale. In this method, NDVI, MSDI and land surface albedo were selected as assessment indicators of desertification to represent land surface conditions from vegetation biomass, landscape pattern and micrometeorology. Based on considering the effects of vegetation type and time of images acquired on assessment indictors, assessing rule sets were built and a decision tree approach was used to assess desertification of Ordos Plateau in 1980, 1990 and 2000. The average overall accuracy of three periods was higher than 90%. The results showed that although some local places of Ordos Plateau experienced an expanding trend of desertification, the trend of desertification of Ordos Plateau was an overall decrease in from 1980 to 2000. By analyzing the causes of desertification processes, it was found that climate change could benefit for the reversion of desertification from 1980 to 1990 at a regional scale and human activities might explain the expansion of desertification in this period; however human conservation activities were the main driving factor that induced the reversion of desertification from 1990 to 2000.

  15. The role of climatic and anthropogenic stresses on long-term runoff reduction from the Loess Plateau, China.

    Science.gov (United States)

    Feng, Xiaoming; Cheng, Wei; Fu, Bojie; Lü, Yihe

    2016-11-15

    Human intervention has strongly altered patterns of river runoff. Yet, few studies have addressed the complexity and nonlinearity of the anthropogenic stresses on runoff or their interaction with climate. We study the Loess Plateau in China, whose river runoff contributes 65% of the discharge to the middle reach of the Yellow River; this landscape has been shaped by human activity and is intensively managed. Our purpose is to characterize the interactive roles of climate and human activities in defining river runoff from the Loess Plateau. Applying a transient analysis to discover the time-varying runoff trend and impact factors, we found that the average runoff in the Loess Plateau decreased continuously during the period 1961-2009 (average rate of -0.9mmyear(-1), Prunoff mainly occurred in three stages, with transitions in 1970, 1981 and 1996. Reduced precipitation was the main reason for the decrease in runoff over the entire study period. However, human intervention played a dominant role in creating the transition points. Water yield (i.e., the ratio of runoff to precipitation) decreased following each anthropogenic transition, causing a 56% reduction in available freshwater resources during the period 1961-2009. These findings highlight the need for studies that address the dynamic and nonlinear processes controlling the availability of freshwater resources in the light of anthropogenic influences applied under a changing climate. Such studies are essential if we are to meet the human water demand in the Loess Plateau region.

  16. Synthesis and Anti-inflammatory Activity of Some Novel 3-(6-Substituted-1, 3-benzothiazole-2-yl-2-[{(4-substituted phenyl amino} methyl] quinazolines-4 (3H-ones

    Directory of Open Access Journals (Sweden)

    Manish Srivastav

    2009-01-01

    Full Text Available A series of novel 3-(6-substituted-1, 3-benzothiazole-2-yl-2-[{(4-substituted phenyl amino} methyl] quinazolines-4(3H-ones were synthesized by treating 2-(chloromethyl-3-(6-substituted-1, 3-benzothiazole-2-yl quinazoline-4-(3H-one (IIa-d with various substituted amine. The compounds (IIa-d prepared by treating 2-[(chloroacetyl amino] benzoic acid with different 2-amino-6-substituted benzothiazole. Elemental analysis, IR, 1HNMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolines-4-one derivative were investigated for their anti-inflammatory and antibacterial activity.

  17. The effect of the Asian Monsoon to the atmospheric boundary layer over the Tibetan Plateau

    Science.gov (United States)

    Li, Maoshan; Su, Zhongbo; Chen, Xuelong; Zheng, Donghai; Sun, Fanglin; Ma, Yaoming; Hu, Zeyong

    2016-04-01

    Modulation of the diurnal variations in the convective activities associated with day-by-day changes of surface flux and soil moisture was observed in the beginning of the monsoon season on the central Tibetan plateau (Sugimoto et al., 2008) which indicates the importance of land-atmosphere interactions in determining convective activities over the Tibetan plateau. Detailed interaction processes need to be studied by experiments designed to evaluate a set of hypotheses on mechanisms and linkages of these interactions. A possible function of vegetation to increase precipitation in cases of Tibetan High type was suggested by Yamada and Uyeda (2006). Use of satellite derived plateau scale soil moisture (Wen et al., 2003) enables the verification of these hypotheses (e.g. Trier et al. 2004). To evaluate these feedbacks, the mesoscale WRF model will be used because several numerical experiments are being conducted to improve the soil physical parameterization in the Noah land surface scheme in WRF so that the extreme conditions on the Tibetan plateau could be adequately represented (Van der Velde et al., 2009) such that the impacts on the structure of the atmospheric boundary layer can be assessed and improved. The Tibetan Observational Research Platform (TORP) operated by the Institute of Tibetan Plateau (Ma et al., 2008) will be fully utilized to study the characteristics of the plateau climate and different aspects of the WRF model will be evaluated using this extensive observation platform (e.g. Su et al., 2012). Recently, advanced studies on energy budget have been done by combining field and satellite measurements over the Tibetan Plateau (e.g. Ma et al., 2005). Such studies, however, were based on a single satellite observation and for a few days over an annual cycle, which are insufficient to reveal the relation between the land surface energy budget and the Asian monsoon over the Tibetan plateau. Time series analysis of satellite observations will provide the

  18. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2016-01-01

    Full Text Available Testis-specific lactate dehydrogenase (LDH-C4 is one of the lactate dehydrogenase (LDH isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4, Lactate Dehydrogenase B4 (LDH-B4, and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE and native polyacrylamide gel electrophoresis (PAGE. The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L, LDH-B4 (Ki = 23.800 mmol/L, and LDH-C4 (Ki = 65.500 mmol/L. These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4.

  19. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae)

    Science.gov (United States)

    Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

    2016-01-01

    Testis-specific lactate dehydrogenase (LDH-C4) is one of the lactate dehydrogenase (LDH) isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae) belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4), Lactate Dehydrogenase B4 (LDH-B4), and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis (PAGE). The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km) of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki) of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L), LDH-B4 (Ki = 23.800 mmol/L), and LDH-C4 (Ki = 65.500 mmol/L). These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4. PMID:26751442

  20. ANALYSIS OF MESOSCALE CONVECTIVE SYSTEMS OVER TIBETAN PLATEAU IN SUMMER

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-yang; DAI Xiao-yan; WU Jian-ping; LIN Hui

    2006-01-01

    In this paper, Geostationary Meteorological Satellite (GMS) infrared black-body temperature (Tbb) data from June to August 1998 are used to automatically track the activity of Mesoscale Convective System (MCS) over the Tibetan Plateau in China. Consequently, the features of MCS, such as area, intensity, life cycle, activity region and shape, are obtained. High Resolution Limited Area Analysis and Forecasting System (HLAFS) values provided by China National Meteorological Center are used to study the relationships between the MCS trajectories and their environmental physical field values, based on the distribution and trajectories of MCSs over the Tibetan Plateau. Favorable environmental physical field charts of influencing MCS movement out of the Tibetan Plateau in different UTC (Universal Time Coordinate) are developed by using spatial data mining techniques at levels of 400hPa and 500hPa, respectively.

  1. More evidence of the plateau effect: a social perspective.

    Science.gov (United States)

    Pinto-Prades, J L; Lopez-Nicolás, A

    1998-01-01

    The purpose of this study was to test the existence of the plateau effect at the social level. The authors tried to confirm the preliminary conclusion that people may not be willing to trade off any longevity to improve the health state of a large number of people if the health states are mild enough. They tested this assumption using the person-tradeoff technique. They also used a parametric approach and a nonparametric approach to study the relationship between individual and social values. Results show the existence of the plateau effect in the context of resource allocation. Furthermore, with the nonparametric approach, a plateau effect in the middle part of the scale was also observed, suggesting that social preference may not be directly predicted from individual utilities. The authors caution against the possible framing effects that may be present in these kinds of questions.

  2. State of tectonic stress in Shillong Plateau of northeast India

    Science.gov (United States)

    Baruah, Santanu; Baruah, Saurabh; Saikia, Sowrav; Shrivastava, Mahesh N.; Sharma, Antara; Reddy, C. D.; Kayal, J. R.

    2016-10-01

    Tectonic stress regime in the Shillong plateau, northeast region of India, is examined by stress tensor inversion. Some 97 reliable fault plane solutions are used for stress inversion by the Michael and Gauss methods. Although an overall NNW-SSE compressional stress is observed in the area, the stress regime varies from western part to eastern part of the plateau. The eastern part of the plateau is dominated by NNE-SSW compression and the western part by NNW-SSE compression. The NNW-SSE compression in the western part may be due to the tectonic loading induced by the Himalayan orogeny in the north, and the NNE-SSW compression in the eastern part may be attributed to the influence of oblique convergence of the Indian plate beneath the Indo-Burma ranges. Further, Gravitational Potential Energy (GPE) derived stress also indicates a variation from west to east.

  3. Fukushima nuclear accident recorded in Tibetan Plateau snow pits.

    Directory of Open Access Journals (Sweden)

    Ninglian Wang

    Full Text Available The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month.

  4. In vitro comparison of tibial plateau leveling osteotomy with and without use of a tibial plateau leveling jig.

    Science.gov (United States)

    Schmerbach, Kay Ingo; Boeltzig, Christian Konrad Matthias; Reif, Ullrich; Wieser, Jan Carsten; Keller, Thomas; Grevel, Vera

    2007-02-01

    To evaluate the influence of a tibial plateau leveling jig on osteotomy orientation, fragment reduction, and postoperative tibial plateau angle (TPA) during tibial plateau leveling osteotomy (TPLO). In vitro experimental study. Large-breed canine cadavers (n=20). TPLO was performed on 40 hindlimbs using 4 methods. Group 1: Jig; dogs in dorsal recumbency with the osteotomy parallel to the distal jig pin. Groups 2-4: No jig; dogs in lateral recumbency with the osteotomy in a vertical orientation (group 2: tibia parallel to the table top; group 3: controlled superimposition of the femoral condyles; group 4: internal rotation of the tibia). Postoperative TPA, fragment reduction, and osteotomy orientation relative to the tibial plateau were compared. Positive or negative values denoted deviation from parallel relative to the tibial plateau. Postoperative TPA, fragment reduction, and proximodistal osteotomy orientation were not significantly different between groups. Craniocaudal osteotomy orientation was significantly different (Ptable surface. TPLO without use of a jig reduces surgical trauma, is less time consuming, and reduces cost.

  5. Outer shelf seafloor geomorphology along a carbonate escarpment: The eastern Malta Plateau, Mediterranean Sea

    Science.gov (United States)

    Micallef, Aaron; Georgiopoulou, Aggeliki; Mountjoy, Joshu; Huvenne, Veerle A. I.; Iacono, Claudio Lo; Le Bas, Timothy; Del Carlo, Paola; Otero, Daniel Cunarro

    2016-12-01

    Submarine carbonate escarpments, documented in numerous sites around the world, consist of thick exposures of Mesozoic shallow water carbonate sequences - primarily limestones and dolomites - with reliefs of >1 km and slope gradients of >70°. Whilst most research efforts have focused on the processes that shaped carbonate escarpments into complex and extreme terrains, little attention has been paid to the geomorphology of shelves upslope of carbonate escarpments. In this study we investigate high resolution geophysical, sedimentological and visual data acquired from the eastern Malta Plateau, central Mediterranean Sea, to demonstrate that the outer shelf of a carbonate escarpment is directly influenced by escarpment-forming processes. We document forty eight erosional scars, six long channels and numerous smaller-scale channels, three elongate mounds, and an elongate ridge across the eastern Malta Plateau. By analysing their morphology, seismic character, and sedimentological properties, we infer that the seafloor of the eastern Malta Plateau has been modified by three key processes: (i) Mass movements - in the form of translational slides, spreading and debris flows - that mobilised stratified Plio-Pleistocene hemipelagic mud along the shelf break and that were likely triggered by seismicity and loss of support due to canyon erosion across the upper Malta Escarpment; (ii) NNW-SSE trending sinistral strike-slip deformation in Cenozoic carbonates - resulting from the development of a mega-hinge fault system along the Malta Escarpment since the Late Mesozoic, and SE-NW directed horizontal shortening since the Late Miocene - which gave rise to NW-SE oriented extensional grabens and a NNW-SSE horst; (iii) Flow of bottom currents perpendicular and parallel to the Malta Escarpment, associated with either Modified Atlantic Water flows during sea level lowstands and/or Levantine Intermediate Water flows at present, which was responsible for sediment erosion and deposition

  6. Multifractal Downscaling of Rainfall Using Normalized Difference Vegetation Index (NDVI) in the Andes Plateau

    Science.gov (United States)

    Posadas, A. N.; Carbajal, M.; Quiroz, R.

    2017-01-01

    In this paper, a multifractal downscaling technique is applied to adequately transformed and lag corrected normalized difference vegetation index (NDVI) in order to obtain daily estimates of rainfall in an area of the Peruvian Andean high plateau. This downscaling procedure is temporal in nature since the original NDVI information is provided at an irregular temporal sampling period between 8 and 11 days, and the desired final scale is 1 day. The spatial resolution of approximately 1 km remains the same throughout the downscaling process. The results were validated against on-site measurements of meteorological stations distributed in the area under study. PMID:28125607

  7. Multifractal Downscaling of Rainfall Using Normalized Difference Vegetation Index (NDVI) in the Andes Plateau.

    Science.gov (United States)

    Duffaut Espinosa, L A; Posadas, A N; Carbajal, M; Quiroz, R

    2017-01-01

    In this paper, a multifractal downscaling technique is applied to adequately transformed and lag corrected normalized difference vegetation index (NDVI) in order to obtain daily estimates of rainfall in an area of the Peruvian Andean high plateau. This downscaling procedure is temporal in nature since the original NDVI information is provided at an irregular temporal sampling period between 8 and 11 days, and the desired final scale is 1 day. The spatial resolution of approximately 1 km remains the same throughout the downscaling process. The results were validated against on-site measurements of meteorological stations distributed in the area under study.

  8. Sur le concept de geosite, des préliminaires au Plateau de Dobroudja du Sud

    Directory of Open Access Journals (Sweden)

    CARMEN CAMELIA RÃDULESCU

    2016-12-01

    Full Text Available The purpose of this article is to analyze the concept of geosite in terms of research in international level and national level, with particularisation on the study of geosites in South Dobrogea Plateau. Geosites are relief forms with a scientific, ecological, aesthetical, archaeological, historical, religious and economical value, in respect of human perception. Inventory and evaluation of the geosites is a complex process of observation, interpretation and award the relief of values, making landforms natural resources, cultural and economic. These values expressed possible synergy between the geological and geomorphological heritage, bioecological and historical-cultural identity and gives a site the identity of geosite.

  9. Receiver function results from the PUDEL (PUna DELamination) Seismic Array in the Southern Puna plateau

    OpenAIRE

    Benjamin Heit; Xiaohui Yuan; Rainer Kind; Kay, S; E. Sandvol; Alonso, R; Coira, B.; Comte, D.

    2010-01-01

    A passive seismic array which operated between December 2007 and November 2010 has been deployed in the southern Puna plateau between 25°S to 28°S latitude and 65W to 70W longitude in Argentina and Chile to address fundamental questions on the processes that form, modify and destroy continental lithosphere and control lithospheric dynamics along Andean-type continental margins. This experiment consisted of 75 stations has been conducted by Argentine, Chilean, German and US scientists and was ...

  10. Discussion on possibilities of taking ground ice in permafrost as water sources on the Qinghai-Tibet Plateau during climate warming

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Large amounts of ground ice are born with permafrost on the Qinghai-Tibet Plateau.Degradation of permafrost resulted from the climate warming will inevitably lead to melting of ground ice.The water released from the melting ground ice enters hydrologic cycles at various levels,and changes regional hydrologic regimes to various degrees.Due to difficulties in monitoring the perma-frost-degradation-release-water process,direct and reliable evidence is few.The accumulative effect of releasing water,however,is remarkable in the macro-scale hydrologic process.On the basis of the monitoring results of water-levels changes in some lakes on the Qinghai-Tibet Plateau,and combined with the previous results of the hydrologic changing trends at the regional scale,the authors preliminarily discussed the possibilities of the degrading permafrost on the Qinghai-Tibet Plateau as a potential water source during climate warming.

  11. Weather and Climate Effects of the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    DUAN Anmin; WU Guoxiong; LIU Yimin; MA Yaoming; ZHAO Ping

    2012-01-01

    Progress in observation experiments and studies concerning the effects of the Tibetan Plateau (TP) on weather and climate during the last 5 years are reviewed.The mesoscale topography over the TP plays an important role in generating and enhancing mesoscale disturbances.These disturbances increase the surface sensible heat (SH) flux over the TP and propagate eastward to enhance convection and precipitation in the valley of Yangtze River.Some new evidence from both observations and numerical simulations shows that the southwesterly flow,which lies on the southeastern flank of the TP,is highly correlated with the SH of the southeastern TP in seasonal and interannual variability.The mechanical and thermal forcing of the TP is an important climatic cause of the spring persistent rains over southeastern China.Moreover,the thermodynamic processes over the TP can influence the atmospheric circulation and climate over North America and Europe by stimulating the large-scale teleconnections such as the Asian-Pacific oscillation and can affect the atmospheric circulation over the southern Indian Ocean.Estimating the trend in the atmospheric heat source over the TP shows that,in contrast to the strong surface and troposphere warming,the SH over the TP has undergone a significant decreasing trend since the mid-1980s.Despite the fact that in situ latent heating presents a weak increasing trend,the springtime atmospheric heat source over the TP is losing its strength.This gives rise to reduced precipitation along the southern and eastern slopes of the TP and to increased rainfall over northeastern India and the Bay of Bengal.

  12. Synthesis and biological evaluation of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position as potential antitumor agents.

    Science.gov (United States)

    Ding, Pan-Pan; Gao, Man; Mao, Bei-Bei; Cao, Sheng-Li; Liu, Cui-Huan; Yang, Chao-Rui; Li, Zhong-Feng; Liao, Ji; Zhao, Hongchang; Li, Zheng; Li, Jing; Wang, Hailong; Xu, Xingzhi

    2016-01-27

    A series of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at the C2-position were synthesized and evaluated for their antiproliferative activities against A549, MCF-7, HeLa, HT29 and HCT-116 cell lines. Most of the synthesized compounds exhibited broad spectrum antitproliferative activity against five cell lines, of which 5c was the most potent against HT29 cell line with an IC50 value of 5.53 μM, inducing a G2/M phase arrest in HT29 cells. Treatment of HT29 cells with 5c resulted in BubR1 phosphorylation and an increase of mitotic index in a time-dependent manner. Furthermore, 5c promoted tubulin polymerization in vitro. These results demonstrate that quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position may be potentially novel antitumor agents targeting tubulin to activate the spindle assembly checkpoint.

  13. Research of Pressure Control System for NC Honing Machine Head%数控珩磨机磨头压力控制研究

    Institute of Scientific and Technical Information of China (English)

    刘冰

    2015-01-01

    珩磨机在珩磨过程中,珩磨头压力的稳定对于发动机缸体等工件的质量有着重要的影响。通过设计电气、液压驱动控制系统,应用PI闭环控制策略,采用比例压力阀作为调压元件,极大地改善了珩磨头工作压力的稳定性并且实现了压力的无级调整。%In working condition, the pressure of honing machine's head must keep stable, and it has an important influence on the quality of the products such as engine cylinder block. The electrical and hydraulic drive control system is designed, the PI close-loop control strategy is applied, the proportional pressure valve is used as pressure regulating devices, so the stability of the honing machine ’s pressure is improved and stepless adjustment of the pressure is realized.

  14. Design, synthesis, and biological evaluation of 3-vinyl-quinoxalin-2(1H-one derivatives as novel antitumor inhibitors of FGFR1

    Directory of Open Access Journals (Sweden)

    Liu Z

    2016-05-01

    Full Text Available Zhiguo Liu,1,* Shufang Yu,1,* Di Chen,1 Guoliang Shen,1 Yu Wang,1 Leping Hou,2 Dan Lin,1 Jinsan Zhang,1 Faqing Ye1 1School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 2Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: FGFR1 is well known as a molecular target in anticancer drug design. TKI258 plays an important role in RTK inhibitors. Utilizing TKI258 as a lead compound that contains a quinazolinone nucleus, we synthesized four series of 3-vinyl-quinoxalin-2(1H-one derivatives, a total of 27 compounds. We further evaluated these compounds for FGFR1 inhibition ability as well as cytotoxicity against four cancer cell lines (H460, B16-F10, Hela229, and Hct116 in vitro. Some compounds displayed good-to-excellent potency against the four tested cancer cell lines compared with TKI258. Structure–activity relationship analyses indicated that small substituents at the side chain of the 3-vinyl-quinoxalin-2(1H-one were more effective than large substituents. Lastly, we used molecular docking to obtain further insight into the interactions between the compounds and FGFR1. Keywords: FGFR1, synthesis, quinoxaline, antitumor activity, kinase inhibitor

  15. SbCl3 as effective catalyst for the preparation of 2,3-Dihydroquinazolin-4(1H)-ones, spectroscopic investigation and DFT study

    Science.gov (United States)

    Pourmousavi, Seied Ali; Kanaani, Ayoob; Fatahi, Hamid Reza; Ghorbani, Fatemeh; Ajloo, Davood

    2017-07-01

    A simple and efficient method has been developed for the synthesis of Quinazolines using SbCl3 as a heterogeneous catalysis at room temperature. This method provides a good pathway for the synthesis of 2,3-Dihydroquinazolin-4(1H)-ones derivatives in the terms of excellent yields and short reaction times. Also we studied theoretically and experimentally on 2-phenyl-2,3-dihydroquinazolin-4(1H)-one (PDQ). Using density functional theory (DFT), the tautomerism of PDQ was also studied. Thermal stability of PDQ was studied by thermo gravimetric analysis (TGA). The spectroscopic results and theoretical calculations indicate that the strength of intramolecular hydrogen bonding (IHB) of PDQ is stronger than that in 2-methyl-4-quinolinol (2MQ). The absorption spectra of the PDQ in solvents with different polarity were obtained and the results show that PDQ exists in both keto-amine and enol-imine forms in THF, while it has keto-amine form in other solvents. Theoretical results show that the conductance of the two tautomers (keto-amine and enol-imine) varies greatly, which offers that the potential usage of this molecule is as a molecular device.

  16. Optimization of 1,2,3,4-tetrahydroacridin-9(10H)-ones as antimalarials utilizing structure-activity and structure-property relationships.

    Science.gov (United States)

    Cross, R Matthew; Maignan, Jordany R; Mutka, Tina S; Luong, Lisa; Sargent, Justin; Kyle, Dennis E; Manetsch, Roman

    2011-07-14

    Antimalarial activity of 1,2,3,4-tetrahydroacridin-9(10H)-ones (THAs) has been known since the 1940s and has garnered more attention with the development of the acridinedione floxacrine (1) in the 1970s and analogues thereof such as WR 243251 (2a) in the 1990s. These compounds failed just prior to clinical development because of suboptimal activity, poor solubility, and rapid induction of parasite resistance. Moreover, detailed structure-activity relationship (SAR) studies of the THA core scaffold were lacking and SPR studies were nonexistent. To improve upon initial findings, several series of 1,2,3,4-tetrahydroacridin-9(10H)-ones were synthesized and tested in a systematic fashion, examining each compound for antimalarial activity, solubility, and permeability. Furthermore, a select set of compounds was chosen for microsomal stability testing to identify physicochemical liabilities of the THA scaffold. Several potent compounds (EC(50) < 100 nM) were identified to be active against the clinically relevant isolates W2 and TM90-C2B while possessing good physicochemical properties and little to no cross-resistance.

  17. Synthesis and biological evaluation of 3-aminoisoquinolin-1(2H)-one based inhibitors of the dual-specificity phosphatase Cdc25B.

    Science.gov (United States)

    George Rosenker, Kara M; Paquette, William D; Johnston, Paul A; Sharlow, Elizabeth R; Vogt, Andreas; Bakan, Ahmet; Lazo, John S; Wipf, Peter

    2015-06-15

    The cell division cycle 25B dual specificity phosphatase (Cdc25B) regulates the normal progression of the mammalian cell cycle by dephosphorylating and activating cyclin-dependent kinase (Cdk) complexes, particularly in response to DNA damage. Elevated Cdc25B levels enable a bypass of normal cell cycle checkpoints, and the overexpression of Cdc25B has been linked to a variety of human cancers. Thus, Cdc25B is an attractive target for the development of anticancer therapeutics. Herein we describe the synthesis and biological evaluation of a series of non-quinoid inhibitors of Cdc25B containing the 3-aminoisoquinolin-1(2H)-one pharmacophore. In addition to several strategies that address specific substitution patterns on isoquinolines, we have applied a regioselective Pd-catalyzed cross-coupling methodology to synthesize a new lead structure, 6-(3-aminophenyl)-3-(phenylamino)isoquinolin-1(2H)-one (13), which proved to be a reversible, competitive Cdc25B inhibitor with a Ki of 1.9μM. Compound 13 prevented human cancer cell growth and blocked Cdc25B-mediated mitotic checkpoint bypass. Molecular docking studies support binding near the catalytic site. Copyright © 2015. Published by Elsevier Ltd.

  18. Application of SCS Model in Estimation of Runoff from Small Watershed in Loess Plateau of China

    Institute of Scientific and Technical Information of China (English)

    LIU Xianzhao; LI Jiazhu

    2008-01-01

    Soil Conservation Service (SCS) model,developed by U.S.Soil Conservation Service in 1972,has been widely applied in the estimation of runoff from an small watershed.In this paper,based on the remote sensing geo-information data of land use and soil classification all obtained from Landsat images in 1996 and 1997 and conventional data of hydrology and meteorology,the SCS model was investigated for simulating the surface runoff for single rainstorm in Wangdonggou watershed,a typical small watershed in the Loess Plateau,located in Changwu County of Shaanxi Province of China.Wangdonggou watershed was compartmentalized into 28 sub-units according to natural draining division,and the table of curve number (CN) values fitting for Wangdonggou watershed was also presented.During the flood period from 1996 to 1997,the hydrograph of calculated runoff process using the SCS model and the hydrograph of observed runoff process coincided very well in height as well as shape,and the model was of high precision above 75%.It is indicated that the SCS model is legitimate and can be successfully used to simulate the runoff generation and the runoff process of typical small watershed based on the remote sensing geo-information in the Loess Plateau.

  19. Multiple-plateau structure and scaling relation in photoelectron spectra of high-order above-threshold ionization

    Institute of Scientific and Technical Information of China (English)

    Wu Yan; Ye Hui-Liang; Zhang Jing-Tao; Guo Dong-Sheng

    2012-01-01

    By developing a full quantum scattering theory of high-order above-threshold ionization,we study the energy spectra and the angular distributions of photoelectrons from atoms with intense laser fields shining on them.We find that real rescattering can occur many times,and even infinite times.The photoelectrons from the rescattering process form a broad plateau in the kinetic-energy spectrum.We further disclose a multiple-plateau structure formed by the high-energy photoelectrons,which absorb many photons during the rescattering process.Moreover,we find that both the angular distributions and the kinetic-energy spectra of photoelectrons obey the same scaling law as that for directly emitted photoelectrons.

  20. 40 CFR 81.162 - Northeast Plateau Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Air Quality Control Regions § 81.162 Northeast Plateau Intrastate Air Quality Control Region. The Northeast Plateau Intrastate Air Quality Control Region (California) consists of the territorial area... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northeast Plateau Intrastate...

  1. Discovery of cryptic Armillaria solidipes genotypes within the Colorado Plateau

    Science.gov (United States)

    J. W. Hanna; N. B. Klopfenstein; M. -S. Kim; S. M. Ashiglar; A. L. Ross-Davis; G. I. McDonald

    2012-01-01

    Armillaria solidipes (= A. ostoyae) is a root-disease pathogen that causes severe losses in growth and productivity of forest trees throughout the Northern Hemisphere. This species is genetically diverse with variable disease activities across different regions of the world. In North America, A. solidipes in the Colorado Plateau exists in drier habitats and causes more...

  2. Spatial Distribution of Soil Erosion Sensitivity on the Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Dan; ZHONG Xiang-Hao; FAN Jian-Rong

    2005-01-01

    The Tibet Plateau, occupying the main part of Qinghai-Tibet Plateau and having an average altitude of 4 500 m, has geomorphological features that are unique in the world, with soil erosion being one of the main ecological problems. Thus the main objectives of the present research were to set up an efficient and simple way of evaluating spatial distribution of soil erosion sensitivity in the Tibet Plateau as well as the responses of soil erosion to changes of natural environmental conditions, and to indicate key regions where soil erosion should be preferentially controlled. Based on the Universal Soil Loss Equation (USLE), the study applied geographic information system (GIS) technology to develop a methodological reference framework, from which soil erosion sensitivity could be evaluated. The impact of precipitation, soil, topography and vegetation on soil erosion was divided into classes of extreme sensitivity, high sensitivity, medium sensitivity, low sensitivity and no sensitivity. With the aid of GIS, the resultant map from overlaying various factors showed that soil erosion sensitivity had great discrepancy in different parts of the region. In the southeastern part of the Tibet Plateau there were mainly three classes of sensitivity, namely, extreme, high and medium sensitivity. However, the other two classes, low and no sensitivity, were dominant in the northwestern part.

  3. Deep mantle forces and the uplift of the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Moucha, R; Forte, A M; Rowley, D B; Mitrovica, J X; Simmons, N A; Grand, S P

    2009-06-23

    Since the advent of plate tectonics, it has been speculated that the northern extension of the East Pacific Rise, specifically its mantle source, has been over-ridden by the North American Plate in the last 30 Myrs. Consequently, it has also been postulated that the opening of the Gulf of California, the extension in the Basin and Range province, and the uplift of the Colorado Plateau are the resulting continental expressions of the over-ridden mantle source of the East Pacific Rise. However, only qualitative models based solely on surface observations and heuristic, simplified conceptions of mantle convection have been used in support or against this hypothesis. We introduce a quantitative model of mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Myrs and its relative advance towards the interior of the southwestern USA. The onset and evolution of the crustal uplift in the central Basin and Range province and the Colorado Plateau is determined by tracking the topographic swell due to this mantle upwelling through time. We show that (1) the extension and magmatism in the central Basin and Range province between 25 and 10 Ma coincides with the reconstructed past position of this focused upwelling, and (2) the southwestern portion of the Colorado Plateau experienced significant uplift between 10 Ma and 5 Ma that progressed towards the northeastern portion of the plateau. These uplift estimates are consistent with a young, ca. 6 Ma, Grand Canyon model and the recent commencement of mafic magmatism.

  4. SUMMER DIURNAL CYCLE AT DOME C ON THE ANTARTIC PLATEAU

    OpenAIRE

    Barral, H.; E. Vignon; Bazile, E.; Traullé, O; Gallée, H.; Genthon, C.; Brun, C.; F. Couvreux; P. Le Moigne

    2014-01-01

    International audience; The ice-sheet offers us ”laboratory cases” with endless snow covered, relatively homogeneous, flat or sloped areas with persistent and strong stable stratifications resulting in low level jets. Dome C (75°06 S,123°E) on the East Antarctic Plateau is one of them.

  5. New transhumance in the Mahafaly Plateau region in Madagascar

    African Journals Online (AJOL)

    models influence people's capacity to adapt, especially in socio- .... pastoral mobility have mainly been described as climate change adaptation strategies ..... transhumance on the plateau, where most herders can build on a ..... and ecosystem services in southern Madagascar. .... Migration as a contribution to resilience.

  6. Ningwu——An Ancient Pass On The Plateau

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>Ningwu situated on the Loess Plateau in north of Shanxi Province is one of the three passes along the Great Wall. The other two are the Pian Pass in the west and the Yanmen Pass in the east. In the ancient times, it had been a key military town in the northern Chinese borders.

  7. Heat Flow for the Minimal Surface with Plateau Boundary Condition

    Institute of Scientific and Technical Information of China (English)

    Kung Ching CHANG; Jia Quan LIU

    2003-01-01

    The heat flow for the minimal surface under Plateau boundary condition is defined to be aparabolic variational inequality, and then the existence, uniqueness, regularity, continuous dependenceon the initial data and the asymptotics are studied. It is applied as a deformation of the level sets inthe critical point theory.

  8. Oil/Gas Exploration Prospects for Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhengzhang; Li Yongtie; Ye Hefei

    1997-01-01

    @@ As an important part of the Tethys, Tibet Plateau is prominent in the global geology tectonics. However, due to the limitation of local geographic conditions, the degree of geological study in this region is low, especially in the field of marine Mesozoic petroleum geological study.

  9. The Colorado Plateau IV: shaping conservation through science and management

    Science.gov (United States)

    Wakeling, Brian F.; Sisk, Thomas D.; van Riper, Charles

    2010-01-01

    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This book focuses on the integration of science and resource management issues in this unique and highly varied environment. Broken into three subsections, this volume addresses conservation biology, biophysical resources, and inventory and monitoring concerns. The chapters range in content, addressing conservation issues–past, present, and future–on the Colorado Plateau, measurement of human impacts on resources, grazing and wildland-urban interfaces, and tools and methods for monitoring habitats and species. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  10. Mapping risk of plague in Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

    2014-07-10

    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  11. Thermal Stratification in Lake Zige Tangco, Central Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    LI Wan-chun; YANG Xiang-dong; YIN Yu; JI Jiang; LI Shi-jie; PU Pei-min

    2005-01-01

    Lake Zige Tangco is an endorheic saline lake in central Tibetan Plateau. Investigations of 1998 and 1999 revealed that is was a typical stratified lake. The characteristics of thermal stratification of the lake have been extensively discussed from 4 aspects, i.e. thermocline, hydrochemistry and dissolved oxygen, stable isotope oxygen, and stability. The thermocline coupled with chemocline was further analyzed.

  12. Structural model of the Balkassar area, Potwar Plateau, Pakistan

    Science.gov (United States)

    Iqbal, Shahid; Akhter, Gulraiz; Bibi, Sehrish

    2015-11-01

    Balkassar is an important hydrocarbon producing area of the Potwar Plateau, Pakistan. Two-dimensional seismic reflection data of the area revealed tectonically controlled, distinct episodes of (1) normal faulting in the basement followed by (2) reverse faulting in the cover sequence. Himalayan orogeny and associated diapirism of the Precambrian Salt Range Formation have produced many salt-cored anticlines in the Potwar Plateau, and one such salt-cored anticline is present in the Balkassar. This anticline has NE-SW-oriented axis, and both the SE and NW limbs are bounded by reverse faults. The basement normal faults indicate Jurassic rifting and splitting of Pangaea. We interpret reverse faults with dip angles of about 60°-75° in the cover sequence, having both hinterland and foreland vergence. Both NW- and SE-dipping faults are present in contrast to the only southward-directed thrusts of previous models. Duplexes and triangle zones, which are common in the northern part of the Potwar Plateau, are not developed in the Balkassar area due to comparatively less crustal shortening in the area. The present interpretation can help in understanding the complex structures in other parts of the Potwar Plateau for hydrocarbons exploration and also in deformed foreland basins worldwide that display similar characteristics but are considered to be dominated by low-angle thrust tectonics.

  13. Interaction between seabed morphology and water masses around the seamounts on the Motril Marginal Plateau (Alboran Sea, Western Mediterranean)

    OpenAIRE

    Palomino, Desirée; Vázquez, J. T.; Ercilla, Gemma; Alonso, Belén; López-González, Nieves; Díaz del Río, Víctor

    2011-01-01

    The seabed morphology in the vicinity of the seamounts on the Motril Marginal Plateau (northern Alboran Sea) was investigated using high-resolution (sparker) and very high-resolution (TOPAS) seismic reflection profiles and multibeam bathymetry. The aim of the study was to determine the recent geological processes, and in particular those that control the contourite depositional system associated with the intermediate and deep Mediterranean water masses. Six groups of morphological features we...

  14. Synthesis and dual D2 and 5-HT1A receptor binding affinities of 5-piperidinyl and 5-piperazinyl-1H-benzo[d]imidazol-2(3H)-ones.

    Science.gov (United States)

    Ullah, Nisar

    2014-04-01

    A series of new 5-piperidinyl and 5-piperazinyl-1H-benzo[d]imidazol-2(3H)-ones have been synthesized and evaluated for dual D2 and 5-HT1A receptor binding affinities. The synthesized ligands are structurally related to bifeprunox, a potential atypical antipsychotic, having potent D2 receptor antagonist and 5-HT1A receptor agonist properties. The Suzuki-Miyaura reaction of cyclic vinyl boronate with appropriate aryl halide yielded arylpiperidine, which was eventually transformed to piperidinyl-1H-benzo[d]imidazol-2(3H)-one. The reductive amination of the latter with appropriate biarylaldehdyes rendered the synthesis of 5-piperidinyl-1H-benzo[d]imidazol-2(3H)-ones. Likewise, the Buchwald-Hartwig coupling reactions of 1-boc-piperazine with appropriate aryl halide and subsequent removal of the boc group rendered arylpiperazine. The reductive amination of the latter with appropriate biarylaldehdyes accomplished the synthesis of 5-piperazinyl-1H-benzo[d]imidazol-2(3H)-ones. The structure-activity relationship studies showed that cyclopentenylpyridine and cyclopentenylbenzyl groups contribute significantly to the dual D2 and 5-HT1A receptor binding affinities of these compounds.

  15. Honing Trajectory Reconstruction and Accuaacy Control for Automotive Engine Cylinder Bore%汽车发动机缸孔珩磨轨迹重构与精度控制

    Institute of Scientific and Technical Information of China (English)

    高罗辉; 张雪萍; 姚振强

    2013-01-01

    This paper ascertains the relationship between the honing head's rotation angle in circumferential direction of the cylinder bore and motion parameters through the analysis and reconstruction of the honing abrasive trajectory. The motion parameters include rotational speed, reciprocating velocity, bottom stroke delays time, and up and down overshoot length. Thus the distribution of the abrasive trajectory is obtained. Based on the research, the paper establishes the corresponding relationship between the honing head motion parameters and the distribution of abrasive trajectory. Finally through the control of abrasive trajectory distribution, it provides a method to improve the cylinder bore honing accuracy.%通过对汽车发动机缸孔珩磨头的运动轨迹的跟踪分析与重构,确定了珩磨头旋转速度、往复运动速度、下端停留时间、上下越程等主要运动参数的变化对珩磨头周向相位角的影响规律,重构磨粒运动轨迹轮廓,建立珩磨关运动参数与磨粒轨迹分布的映射关系模型.基于该模型,探索了控制珩磨轨迹分布的均匀性的看法,改善了缸孔珩磨精度.

  16. PIFA-BF3·OEt2 mediated intramolecular regioselective domino cyclization of ynamides: A novel method for the synthesis of tetrahydroisoquinoline-oxazol-2(3H)-ones.

    Science.gov (United States)

    Ieawsuwan, Winai; Ruchirawat, Somsak

    2017-06-01

    The transition metal-free intramolecular regioselective domino cyclization of N-Boc protected ynamides has been developed to provide the corresponding tetrahydroisoquinoline-oxazo-2(3H)-ones in moderate to good yields. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Facile Diversity-Oriented Multicomponent One-Pot Synthesis of 3-Amino-6,7-dihydrobenzo[c]thiophen-4(5H)-one Derivatives from alpha-Oxo-N,S-ketene Acetal

    NARCIS (Netherlands)

    Yerande, Swapnil G.; More, Sunil D.; Bhandari, Mayur; Newase, Kiran M.; Khoury, Kareem; Wang, Kan; Doemling, Alexander

    2014-01-01

    A convenient one-pot multicomponent method for the preparation of 3-amino-6,7-dihydrobenzo[c]thiophen-4(5H)-one derivative has been developed. Reaction of 1,3-cyclohexanedione and phenyl isothiocynate gave -oxo-N,S-ketene acetal that were reacted in situ with 2-chloromethylquniazoline-4-one derivati

  18. The mechanism of unexpected reduction of dimethyl pyridine-2,3-dicarboxylate to 1,2,3,4-tetrahydrofuro[3,4-b]-pyridin-5(7H)-one with sodium borohydride

    Institute of Scientific and Technical Information of China (English)

    Yan Bo Tang; Qing Jian Zhang; De Quan Yu

    2012-01-01

    An unexpected reduction of dimethyl pyridine-2,3-dicarboxylate to 1,2,3,4-tetrahydrofuro[3,4-b]pyridin-5(7H)-one with sodium borohydride in ethanol and tetrahydrofuran,respectively,is described,a hypothetic mechanism for the unusual reductive product is proposed.

  19. TIBIAL PLATEAU FRACTURES – SURGICAL MANAGEMENT BY MIPPO

    Directory of Open Access Journals (Sweden)

    Bharath Raju

    2014-06-01

    Full Text Available BACKGROUND AND OBJECTIVES: Tibial plateau fractures are one of the most common intra-articular fractures. They are the outcome of indirect coronal or direct compressive forces. The incidence of tibial plateau fractures is 1.3% of all fractures. These fractures have varied degree of fracture configuration involving medial, lateral or both tibial plateaus with varied degree of intra-articular depressions and displacements. Due to speedy vehicles and mechanization there has been increase in the number of tibial plateau fractures. Knee joints being one of the major weight bearing joints of human body, these fractures are of big importance. METHODS: We studied 30 cases of tibial plateau fractures treated by MIPPO at kempegowda institute of medical sciences from June 2012 to April 2014 with minimum follow up of up to 6months. RESULTS: All the selected patients were evaluated both clinically as well as radiologically. The lab investigations were done and then they were taken up for the surgery. The fractures were classified as per schatzker’s classification and treated accordingly. In the post-op period early range of movements were started and the patients were non weight bearing till 6 weeks. Till 12 weeks partial weight bearing was allowed and full weight bearing was allowed after radiological union of the fracture. CONCLUSION: Tibial plateau fractures when treated with MIPPO give articular anatomical reduction, rigid fixation and early mobolisation of the knee joint. This prevents development of osteoarthritis and includes all the advantages of minimally invasive procedure and so better patient compliance.

  20. Morphostructural characterization of the western edge of the Huila Plateau (SW Angola), based on remote sensing techniques

    Science.gov (United States)

    Lopes, Fernando Carlos; Pereira, Alcides José; Mantas, Vasco Manuel; Mpengo, Horácio Kativa

    2016-05-01

    Recognition of the main morphostructural features of the western edge of the Huila Plateau (SW Angola) can be done by using remote sensing techniques associated with field work. A digital elevation model (DEM) of the area was built for this purpose. This model is based on altimeter data acquired from the Aster sensor, on which image processing techniques such as enhancement techniques, contrast change and filtering were applied. Other techniques, such as RGB colour composition, were also tested. The processed satellite images were interpreted by visual process and the results were then compared with available geological maps (scale 1: 1 000 000). To facilitate both analysis and interpretation, the edge of the plateau was divided into three sectors: northern (or Chongoroi Edge), central (or Humpata Edge) and southern (or Oncocua Edge). For each sector, the main morphological aspects and main lineament systems were identified and characterized. In the specific case of the central sector, these parameters were also confirmed by field work. This study shows that the morphology of the western edge of the plateau is dominated by N50°W-N60°W, N60°E and N-S trending main tectonic systems. These results have important implications in terms of geological mapping and regional tectonics as well as in land-use planning and other areas, such as hydrogeology or geotechnics.

  1. Theoretical Analysis and Experimental Study of an Adjustable Honing Head for Hole Finishing%内孔光整可调珩磨头的理论分析与试验研究

    Institute of Scientific and Technical Information of China (English)

    陈世彬; 杨胜强; 李文辉

    2016-01-01

    ABSTRACT:Objective At present, a honing head can only hone holes with a single size, which is poor in suitability. In order to improve the versatility of honing head and to adapt low-volume and multi-standard honing, an adjustable honing head was in-troduced.Methods Adjustment principle of this honing head was introduced. The honing force suffered by workpiece and the movement of this honing head were analyzed. The 3D modeling was built using the software SolidWorks, and the physical pro-totype which adapted to the inner diameter from 95 mm to 125 mm was manufactured. Experiments were carried out using stainless steel pipe with inner diameter of 98 mm and 106 mm respectively. After 6 minutes of honing, theRa curve and surface topography were acquired.ResultsRa decreased from 2.174μm to 0.869μm for the stainless steel pipe with inner diameter of 98 mm, andRa decreased from 1.582μm to 0.758μm for the one with inner diameter of 106 mm. The surface became smooth and bright, and the surface topography was significantly improved.Conclusion The honing head described in this article was simple and easy to use, and it could be used on general machine tool. The feasibility of this device was verified by experiments.%目的:目前对内孔的珩磨加工,一种珩磨头只能加工一种口径的内孔,加工尺寸单一,适应性差。为了提高珩磨头的通用性,适应小批量、多规格珩磨加工,介绍一种尺寸可调的珩磨头。方法对珩磨头尺寸调节原理进行了介绍,并分析了珩磨时工件所受的珩磨力以及珩磨头的运动情况。用SolidWorks建立了装置的三维模型,并加工出了适应孔径为95~125 mm的珩磨头实物样机。通过对内径为φ98 mm和φ106 mm的不锈钢钢管进行加工实验,加工6 min后,获取了表面粗糙度Ra变化曲线和加工后的表面形貌。结果加工后φ98 mm管的表面粗糙度Ra值由2.174μm降低到0.869μm,φ106 mm管的表面粗糙度由1.582

  2. A New Technique for Composting Livestock Manure on the Cold Qinghai-Tibet Plateau, China

    Directory of Open Access Journals (Sweden)

    FAN Yue

    2014-08-01

    Full Text Available Livestock manure compositing on the cold Qinghai-Tibet Plateau is a feasible way to utilize manure while alleviating negative en-vironmental effects. In order to overcome unfavorable factors of cold temperature and shortage of manpower for composting operation, we de-veloped a new technique for composting livestock manure on the Qinghai-Tibet plateau:static ventilation-double-layer film insulation and studied the effect of it. The static ventilation had been achieved by ventilation pipes implanted in compost stacks while double-layer film mulching had prevented heat loss from composting process. Composting trials showed that compared with pile turning over, the static ventila-tion pipes significantly shortened the time for temperature rise and reduced the temperature difference between interior and outer layers of compost stacks, and thus speeded up the composting process meanwhile reducing losses of nutrients during composting. The double-layer film mulching further helped maintain the temperature of compost stacks. By this new technique, the operation of overturning compost stacks was not a necessity for composting livestock manure. Adding phosphorus fertilizers to manure for composting also helped to increase tempera-ture but this had a possibility to increase losses of nitrogen and organic matters from composts.

  3. Effects of Accelerated Soil Erosion on Soil Nutrient Loss After Deforestation on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fen-Li

    2005-01-01

    Soil erosion and nutrient losses on newly-deforested lands in the Ziwuling Region on the Loess Plateau of China were monitored to quantitatively evaluate the effects of accelerated soil erosion, caused by deforestation, on organic matter,nitrogen and phosphorus losses. Eight natural runoff plots were established on the loessial hill slopes representing different erosion patterns of dominant erosion processes including sheet, rill and shallow gully (similar to ephemeral gully). Sediment samples were collected after each erosive rainfall event. Results showed that soil nutrients losses increased with an increase of erosion intensity. Linear relations between the losses of organic matter, total N, NH4-N, and available P and erosion intensity were found. Nutrient content per unit amount of eroded sediment decreased from the sheet to the shallow gully erosion zones, whereas total nutrient loss increased. Compared with topsoil, nutrients in eroded sediment were enriched,especially available P and NH4-N. The intensity of soil nutrient losses was also closely related to soil erosion intensity and pattern with the most severe soil erosion and nutrient loss occurring in the shallow gully channels on loessial hill slopes.These research findings will help to improve the understanding of the relation between accelerated erosion process after deforestation and soil quality degradation and to design better eco-environmental rehabilitation schemes for the Loess Plateau.

  4. Nebkha development and its relationship to environmental change in the Alaxa Plateau, China

    Science.gov (United States)

    Wang, Xunming; Xiao, Honglang; Li, Jinchang; Qiang, Mingrui; Su, Zhizu

    2008-11-01

    Extensive nebkha areas develop mainly under the control of aeolian processes, and their sediments record information on regional environmental changes during different periods. Such areas have developed on the dry riverbeds and deserted arable lands of China’s Alaxa Plateau, Taklimakan, and Kumutage deserts. In this paper, we studied nebkhas that had developed in the Heicheng Juyan region to determine their CaCO3 contents, particle size distributions, and creation dates. Extensive human activities have occurred in this region since at least in the late Tang Dynasty (618 907 ad). Although historical records show that most of the region’s rivers dried up around 1372, surface water persisted in some areas until the early Qing Dynasty (1644 1911 ad). After the 1600s, extensive nebkhas began to develop due to drying of the region’s rivers. The early stages of nebkha development were controlled by both the sediment supply and the regional wind regime, whereas late stages were controlled primarily by variations in wind activity. In the Alaxa Plateau, it took about 100 years for arable lands and riverbeds to evolve into gobi deserts, and during this time, several phases occurred with different levels of wind activity. The land degradation processes in this region are mainly controlled by surface water resources, and the impact of human activities such as reclamation on land degradation appear to have been overestimated in previous studies.

  5. An experimental method to verify soil conservation by check dams on the Loess Plateau, China.

    Science.gov (United States)

    Xu, X Z; Zhang, H W; Wang, G Q; Chen, S C; Dang, W Q

    2009-12-01

    A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model-prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D(a) and D(b), have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.

  6. Quadrant Dynamic with Automatic Plateau Limit Histogram Equalization for Image Enhancement

    Directory of Open Access Journals (Sweden)

    P. Jagatheeswari

    2014-01-01

    Full Text Available The fundamental and important preprocessing stage in image processing is the image contrast enhancement technique. Histogram equalization is an effective contrast enhancement technique. In this paper, a histogram equalization based technique called quadrant dynamic with automatic plateau limit histogram equalization (QDAPLHE is introduced. In this method, a hybrid of dynamic and clipped histogram equalization methods are used to increase the brightness preservation and to reduce the overenhancement. Initially, the proposed QDAPLHE algorithm passes the input image through a median filter to remove the noises present in the image. Then the histogram of the filtered image is divided into four subhistograms while maintaining second separated point as the mean brightness. Then the clipping process is implemented by calculating automatically the plateau limit as the clipped level. The clipped portion of the histogram is modified to reduce the loss of image intensity value. Finally the clipped portion is redistributed uniformly to the entire dynamic range and the conventional histogram equalization is executed in each subhistogram independently. Based on the qualitative and the quantitative analysis, the QDAPLHE method outperforms some existing methods in literature.

  7. Rangeland Privatization and Its Impacts on the Zoige Wetlands on the Eastern Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    YAN Zhaoli; WU Ning

    2005-01-01

    The high Zoige Basin (Ruoergai Plateau) on the eastern Tibetan Plateau is a fault depression formed during intensive uplifting of the Tibetan Plateau. The wetland is globally important in biodiversity and is composed of marshes, bogs, fens, wet meadows and shallow water interspersed with low hills and sub-alpine meadows. Most of the Zoige wetlands have long been one of the most important grazing lands in China. Recent rangeland policy has allowed grazing, and usable wetland areas have been being legally allocated to individuals or groups of households on a long-term lease basis. Privatization of the wetland has impacted the Zoige wetlands in aspects of hydrologic condition, landscape and biodiversity. The uneven spatial distribution of water resources on private lands has led to the practice of extracting ground water, which has decreased the perched water table in Zoige. Fencing off the rangelands and grazing on expanding sand dunes have affected landscapes. Variation in the water table has led to the changes in vegetation diversity, resulting in the changes in wildlife and aquatic diversities and ecosystem processes. Making use all year round of the pasture that was previously grazed only in summer has shrunk the daily activity space of wildlife, and the newly erected fences blocked the movement of wild animals looking for food in the snow to lower and open areas. To maintain the favorable conditions of the Zoige wetland ecosystem, the author suggests that, in addition to biophysical research and implementation of conservation practices, there is an immediate need to initiate an integrated management program, increase public awareness of wetland functions and provide better training for the local conservation staff.

  8. Aerosol effects on the development of cumulus clouds over the Tibetan Plateau

    Science.gov (United States)

    Zhou, Xu; Bei, Naifang; Liu, Hongli; Cao, Junji; Xing, Li; Lei, Wenfang; Molina, Luisa T.; Li, Guohui

    2017-06-01

    The aerosol-cloud interaction over the Tibetan Plateau has been investigated using a cloud-resolving weather research and forecasting model with a two-moment bulk microphysical scheme including aerosol effects on cloud condensation nuclei and ice nuclei. Two types of cumulus clouds with a similar convective available potential energy, occurring over the Tibetan Plateau (Cu-TP) and North China Plain (Cu-NCP) in August 2014, are simulated to explore the response of convective clouds to aerosols. A set of aerosol profiles is used in the simulations, with the surface aerosol number concentration varying from 20 to 9000 cm-3 and the sulfate mass concentration varying from 0.02 to 9.0 µg cm-3. Increasing aerosol concentrations generally enhances the cloud core updraft and maximum updraft, intensifying convections in Cu-TP and Cu-NCP. However, the core updraft is much stronger in Cu-TP than Cu-NCP, because of the early occurrence of the glaciation process in Cu-TP that is triggered at an elevation above 4000 m. The precipitation increases steadily with aerosol concentrations in Cu-NCP, caused by the suppression of the warm rain but occurrence of efficient mix-phased precipitation due to the reduced cloud droplet size. The precipitation in Cu-TP also increases with aerosol concentrations, but the precipitation enhancement is not substantial compared to that in Cu-NCP with high aerosol concentrations. The aerosol-induced intensification of convections in Cu-TP not only facilitates the precipitation but also transports more ice-phase hydrometeors into the upper troposphere to decrease the precipitation efficiency. Considering the very clean atmosphere over the Tibetan Plateau, elevated aerosol concentrations can remarkably enhance convections due to its specific topography, which not only warms the middle troposphere to influence the Asian summer monsoon but also delivers hydrometeors into the upper troposphere to allow more water vapor to travel into the lower stratosphere.

  9. Records of anthropogenic antimony in the glacial snow from the southeastern Tibetan Plateau

    Science.gov (United States)

    Zhang, Yulan; Kang, Shichang; Chen, Pengfei; Li, Xiaofei; Liu, Yajun; Gao, Tanguang; Guo, Junming; Sillanpää, Mika

    2016-12-01

    Antimony (Sb) is a ubiquitous element in the environment that is potentially toxic at very low concentrations. In this study, surface snow/ice and snowpit samples were collected from four glaciers in the southeastern Tibetan Plateau in June 2015. The concentrations of Sb and other elements were measured in these samples. The results showed that the average concentration of Sb was approximately 2.58 pg g-1 with a range of 1.64-9.20 pg g-1. The average Sb concentration in the study area was comparable to that recorded in a Mt. Everest ice core and higher than that in Arctic and Antarctic snow/ice but much lower than that in Tien Shan and Alps ice cores. Sb presented different variations with other toxic elements (Pb and Cr) and a crustal element (Al) in the three snowpits, which indicated the impact of a different source or post-deposition processes. The enrichment factor of Sb was larger than 10, suggesting that anthropogenic sources provided important contributions to Sb deposition in the glaciers. The Sb in the glacial snow was mainly loaded in the fourth component in principal component analysis, exhibiting discrepancies with crustal elements (Fe and Ca) and other toxic metals (Pb). Backward trajectories revealed that the air mass arriving at the southeastern Tibetan Plateau mostly originated from the Bay of Bengal and the South Asia in June. Thus, pollutants from the South Asia could play an important role in Sb deposition in the studied region. The released Sb from glacier meltwater in the Tibetan Plateau and surrounding areas might pose a risk to the livelihoods and well-being of those in downstream regions.

  10. Cenozoic basin development and its indication of plateau growth in the Xunhua-Guide district

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Xunhua, Guide and Tongren Basins are linked with the Laji Mountain and the northern West Qinling thrust belts in the Xunhua-Guide district. Basin depositional stratigraphy consists of the Oligocene Xining Group, the uppermost Oligocene-Pliocene Guide Group and the Lower Pleistocene. They are divided into three basin phases by unconformities. Basin phase 1 is composed of the Xining Group, and Basin phase 2 of the Zharang, Xiadongshan, Herjia and Ganjia Conglomerate Formations in the Guide Group, and Basin phase 3 of the Gonghe Formation and the Lower Pleistocene. Three basin phases all develop lacustrine deposits at their lower parts, and alluvial-braided channel plain depositional systems at upper parts, which constitute a coarsening-upward and progradational sequence. Basin deposition, paleocurrent and provenance analyses represent that large lacustrine basin across the Laji Mountain was developed and sourced from the West Qinling thrust belt during the stage of the Xining Group (Basin phase 1), and point-dispersed alluvial fan-braided channel plain deposition systems were developed beside the thrust and uplifted Laji Mountain and sourced from it, as thrusting migrated northwards during the stage of the Guide Group (Basin phase 2). Evolution of basin-mountain system in the study area significantly indicates the growth process of the distal Tibetan Plateau. The result shows that the Tibetan Plateau expanded to the northern West-Qinling at Oligocene (29―21.4 Ma) by means of northward folded-and-thrust thickening and uplifting and frontal foreland basin filling, and across the study area to North Qilian and Liupan Mountain at the Miocene-Pliocene (20.8―2.6 Ma) by means of two-sided basement-involved-thrust thickening and uplifting and broken foreland basin filling, and the distant end of Tibetan Plateau behaved as regional erosion and intermontane basin aggradational filling during the Pliocene and early Pleistocene (2.6―1.7 Ma).

  11. Keeping the Edges Sharp I: Honing the Theory of Narrow Rings

    Science.gov (United States)

    Hamilton, Douglas P.; Rimlinger, Thomas; Hahn, Joseph M.

    2016-05-01

    Most of the rings that encircle Saturn, Uranus, and Neptune are very narrow structures with typical radial widths of just a few kilometers. Such extreme sharpness is surprising, as even slightly different orbital periods should allow ring particles to continually jostle one another in collisions that preserve angular momentum whileinexorably draining energy. Sharp edges should blur as rings spread in response to collisions and yet they do not. The generally accepted solution to this dilemma is to bracket each narrow ring with a pair of shepherding satellites that can pump energy back into the ring to replace that lost by collisions. But only a disappointing two of roughly twenty narrow rings actually have known attendant satellites. We present a compelling alternative in which the slight eccentricities and inclinations of narrow ringlets act as internal energy sources that can be tapped to prevent ring spreading. When unattended circular rings dissipate energy they must spread radially in order to preserve angular momentum. By contrast, eccentric or inclined rings have an extra degree of freedom that can be exploited to prevent radial spreading; energy is dissipated while keeping z-component of angular momentum, sqrt(a(1-e^2))cos(i), constant by simply decreasing the overall eccentricity (e) and/or inclination (i) of the entire ring. A real narrow ring moves inward as a unit, circularizes, and drops into the equatorial plane in a process that deters radial spreading for millions or billions of years. Using secular theory with dissipation (Zhang et al. 2013), we show that narrow rings are secular eigenstates in which ellipses are nested with pericenters almost, but not exactly aligned. The misalignment of pericenters is crucial in allowing energy dissipation to be shared evenly across the ring. We predict ring surface densities that are roughly constant across the ring's width, in contrast to profiles expected for shepherded rings. Rimlinger et al. (this meeting

  12. Educating surgeons for the new golden hours: honing the skills of palliative care.

    Science.gov (United States)

    Huffman, Joan L

    2005-04-01

    All surgeons should maintain a lifetime commitment to education and learning. Those who already are in practice need to make the effort to obtain or refresh their education in basic competencies in palliative care and to provide a measured balance between philosophy and practical skills. Many resources and teaching tools are available to assist in this continuing process: surgical peers (and peers from other medical specialties),journals, textbooks, CME conferences, surgical governance and educational organizations, and palliative care websites. A tremendous summary article on palliative care education for surgeons was published recently in JACS[24]. Surgeons must be competent in the following palliative care skills:communication, holistic patient evaluation, control of pain and symptoms,understanding legal/ethical issues, withdrawing care, and the continuum of acute to chronic to terminal care. If they cannot attend to all of these areas individually, they need to be aware of the local, regional, and national resources that are available to assist the patient (or their surrogate decision maker) and themselves in the end-of-life arena. Consultations and referrals should be accomplished in such a manner that the patient does not feel abandoned by his/her surgeon at such a critical point in his/her life. Practicing surgeons also must be involved actively in the education of resident and medical students in didactic and clinical situations. Most importantly, they must model the appropriate behaviors for their charges personally, whether it be in the consultation room breaking bad news compassionately or at the bedside easing the path to the next world. In these golden hours, the educated surgeon who wields new and mighty resources can be the greatest champion of the patient who is at the end of life.

  13. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

    Science.gov (United States)

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the

  14. Analysis, synthesis and design of chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Turton, R. [West Virginia Univ., Morgantown, WV (United States); Bailie, R.C.; Whiting, W.B.

    1998-12-31

    The book illustrates key concepts through a running example from the real world: the manufacture of benzene; covers design, economic considerations, troubleshooting and health/environmental safety; and includes exclusive software for estimating chemical manufacturing equipment capital costs. This book will help chemical engineers optimize the efficiency of production processes, by providing both a philosophical framework and detailed information about chemical process design. Design is the focal point of the chemical engineering practice. This book helps engineers and senior-level students hone their design skills through process design rather than simply plant design. It introduces all the basics of process simulation. Learn how to size equipment, optimize flowsheets, evaluate the economics of projects, and plan the operation of processes. Learn how to use Process Flow Diagrams; choose the operating conditions for a process; and evaluate the performance of existing processes and equipment. Finally, understand how chemical process design impacts health, safety, the environment and the community.

  15. Interseismic deformation of the Central Tibetan Plateau measured using InSAR

    Science.gov (United States)

    Garthwaite, M. C.; Wright, T. J.

    2009-12-01

    Contrasting models have been proposed to describe the ongoing deformation of the Tibetan plateau as a result of the shortening imposed by the India-Asia Collision. One extreme involves rigid rotations of coherent blocks bounded by major faults which penetrate the entire lithosphere. The rigidity of each block implies that there is minimal internal deformation. This description implies relatively high slip rates on block bounding faults separated by narrow shear zones. In the alternative extreme, the bulk continental lithosphere is considered to deform continuously as a viscous fluid. Deformation in the brittle upper crust is driven by tractions imparted on its base from the viscous layer beneath, and distributed on a large number of shallow faults throughout the deforming zone. As a result, slip rates on faults are lower, and the number of discrete crustal blocks is larger. Geodetic observations of interseismic deformation around locked faults often show concentrated strain. If crustal blocks are separated by distances less than or equal to the locking depth (i.e. many small blocks), their straining zones will merge together. If a few large blocks exist, their strain zones should be distinct. There are very few GPS measurements of surface velocity in the plateau interior, therefore it has been difficult to verify either of the proposed models. Interferometric synthetic aperture radar (InSAR) is a powerful technique which dramatically increases the spatial density of velocity measurements. By combining multiple interferograms, interseismic strain can be measured using InSAR with an accuracy of approximately 6 millimetres per year (Wang et. al. GRL, 2009). We use 32 Envisat ASAR images acquired between 2003 and 2009 on descending track 176 in the plateau centre. The swath length of ~1500 km spans the entire plateau including the four major east-west trending strike-slip faults of Tibet - the Altyn Tagh, Kunlun, Jiali, and Xianshuihe. Interferograms are processed

  16. [The pathogenic ecology research on plague in Qinghai plateau].

    Science.gov (United States)

    Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun

    2013-12-01

    To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial

  17. Deformation Mechanism of the Northern Tibetan Plateau as Revealed by Magnetotelluric Data

    Science.gov (United States)

    Zhang, Letian; Wei, Wenbo; Jin, Sheng; Ye, Gaofeng; Xie, Chengliang

    2017-04-01

    As a unique geologic unit on the northern margin of the Tibetan Plateau, the Qaidam Basin plays a significant role in constraining the vertical uplift and horizontal expansion of the northern and northeastern Tibetan Plateau. However, due to its complex evolution history and difficult logistic condition, deformation mechanism of the lithosphere beneath the Qaidam Basin is still highly debated. To better understand the lithospheric electrical structure and deformation mechanism of the Qaidam Basin, A 250 km long, NE-SW directed Magnetotelluric (MT) profile was finished in the northern portion of the Basin, which is roughly perpendicular to the thrust fault systems on the western and eastern margins of the Basin, as well as anticlinorium systems within the Basin. The profile consists of 20 broad-band MT stations and 5 long-period MT stations. Original time series data is processed with regular robust routines. Dimensionality and regional strike direction are determined for the dataset through data analysis. Based on the analysis results, 2D inversions were performed to produce a preferred model of the lithospheric electrical structure beneath the northern Qaidam Basin. Uncertainty analysis of the 2D inversion model was also conducted based on a data resampling approach. The outcome 2D electrical model was further used to estimate the distribution of temperature and melt fraction in the upper mantle based on laboratory-determined relationships between the electrical conductivity and temperature of nominally anhydrous minerals and basaltic melt by using the mixing law of Hashin-Shtrikman's bounds. All these results suggest that: (1) the crust-mantle boundary is imaged as a conductive layer beneath the western Qaidam Basin, with its temperature estimated to be 1200-1300 °C and melt fraction 5-8%, indicating decoupling deformation of the crust and upper mantle. (2) A large-scale east-dipping conductor is imaged beneath the eastern Qaidam Basin. This conductor extends

  18. Post-rift volcanic structures of the Pernambuco Plateau, northeastern Brazil

    Science.gov (United States)

    Buarque, Bruno V.; Barbosa, José A.; Magalhães, José R. G.; Cruz Oliveira, Jefferson T.; Filho, Osvaldo J. Correia

    2016-10-01

    The Pernambuco marginal basin is located on the eastern continental margin of northeastern Brazil, covers an area of 20,800 km2, and represents one of the most prominent frontiers for deep water oil and gas exploration off the Brazilian coast. The onshore region of this basin was highly affected by extrusive and intrusive magmatism during the Upper Albian, and the relation of that event with the volcanic structures observed in the offshore sector has not been thoroughly characterized to date. This study aims to characterize the major extrusive and intrusive volcanic structures of the offshore portion of this basin, which is dominated by the Pernambuco Plateau, and its stratigraphic relations. A set of 143 2D multichannel seismic sections that cover the Pernambuco Plateau region are used to interpret the major tectono-stratigraphic sequences and describe the distribution of volcanoes, sills, vent complexes and related volcaniclastic sequences. The interpretations are supported by aeromagnetic and gravimetric geophysical surveys. Volcanoes are classified into two groups that differ in terms of their morphology: shield-like structures and cone-shaped volcanic structures. Sill intrusions are mainly identified beneath the volcanic structures and are characterized by high-amplitude reflectors with short extensions and abrupt terminations. Volcaniclastic sequences are found adjacent to the volcanoes and are characterized by high-amplitude, disrupted reflections with local chaotic configurations. Vent complexes are classified on the basis of their morphologies as either eye-shaped or crater-shaped. The volcanic features identified within the available seismic dataset are concentrated in two main areas: in the centre of the plateau and near its northeastern border. These two regions are host basement outer highs and are surrounded by hyper-extended continental crust, which forms the plateau itself. The extrusive and intrusive features described in the offshore region were

  19. A new phasmid gecko (Squamata: Diplodactylidae: Strophurus) from the Arnhem Plateau: more new diversity in rare vertebrates from northern Australia.

    Science.gov (United States)

    Oliver, Paul M; Parkin, Tom

    2014-10-22

    The Arnhem Plateau is a rugged expanse of sandstone escarpment in the Australian Monsoonal Tropics with a highly endemic biota. Here we describe a new species of small spinifex dwelling Strophurus (phasmid gecko) that also appears to be endemic to this region. Strophurus horneri sp. nov. can be diagnosed from all congeners by aspects of size, coloration and scalation. Even with the description of this new species, however, levels of morphological and genetic diversity within Strophurus from the stone country of the Northern Territory suggest additional divergent lineages are present. A number of recent studies have now provided preliminary evidence of evolutionary diversity within the Arnhem Plateau, but data remains scant and almost nothing is known about how topography and historical processes have shaped the endemic biota of this region. 

  20. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Science.gov (United States)

    Xie, Y.; Wei, F.; Chen, G.; Zhang, T.; Hu, L.

    2010-06-01

    Four successive storms with freezing rain and snow blanketed South China from 10 January-2 February 2008, when the precipitation increased more than 200%-300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV) measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA), has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January-29 January and 31 January-2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January-16 January and 18 January-22 January was significantly related to the abnormal variation of the one day pre-observation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models.

  1. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y. [Texas A and M Univ., College Station, TX (United States). Dept. of Atmospheric Sciences; Wei, F.; Chen, G.; Zhang, T. [Chinese Academy of Meteorological Sciences, Beijing (China). State Key Lab. of Severe Weather; Hu, L. [Texas A and M Univ., College Station, TX (United States). Dept. of Oceanography

    2010-07-01

    Four successive storms with freezing rain and snow blanketed South China from 10 January-2 February 2008, when the precipitation increased more than 200%- 300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV) measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA), has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January-29 January and 31 January-2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January-16 January and 18 January-22 January was significantly related to the abnormal variation of the one day preobservation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models. (orig.)

  2. Analysis of the 2008 heavy snowfall over South China using GPS PWV measurements from the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Y. Xie

    2010-06-01

    Full Text Available Four successive storms with freezing rain and snow blanketed South China from 10 January–2 February 2008, when the precipitation increased more than 200%–300% above the average for the corresponding period. The unusual atmospheric circulation associated with these disasters was caused by many complex physical processes, one of which was the active southern branch of currents over low latitude ocean areas which provided plenty of water vapor for South China. The ground-based GPS Precipitable Water Vapor (PWV measurements on the Tibetan Plateau, supported by the China and Japan Intergovernmental Cooperation Program (JICA, has compensated for the lack of conventional observations of atmospheric water vapor in this area and provided a good opportunity to analyze the character of the water vapor transport in the four heavy precipitation processes. It was found that the GPS stations located on the southeastern Tibetan Plateau were on the route of the water vapor transport during 25 January–29 January and 31 January–2 February when two heavy precipitation events occurred over South China. The increasing trend from the one to two days pre-observation by the GPS stations was then associated with the heavy precipitation. Precipitation during 10 January–16 January and 18 January–22 January was significantly related to the abnormal variation of the one day pre-observation by the GPS stations located on the northeastern Tibetan Plateau. This research indicates that ground-based GPS measurements are applicable to data assimilation in operational numerical models.

  3. Assessment of satellite rainfall products over the Andean plateau

    Science.gov (United States)

    Satgé, Frédéric; Bonnet, Marie-Paule; Gosset, Marielle; Molina, Jorge; Hernan Yuque Lima, Wilson; Pillco Zolá, Ramiro; Timouk, Franck; Garnier, Jérémie

    2016-01-01

    Nine satellite rainfall estimations (SREs) were evaluated for the first time over the South American Andean plateau watershed by comparison with rain gauge data acquired between 2005 and 2007. The comparisons were carried out at the annual, monthly and daily time steps. All SREs reproduce the salient pattern of the annual rain field, with a marked north-south gradient and a lighter east-west gradient. However, the intensity of the gradient differs among SREs: it is well marked in the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis 3B42 (TMPA-3B42), Precipitation Estimation from remotely Sensed Information using Artificial Neural Networks (PERSIANN) and Global Satellite Mapping of Precipitation (GSMaP) products, and it is smoothed out in the Climate prediction center MORPHing (CMORPH) products. Another interesting difference among products is the contrast in rainfall amounts between the water surfaces (Lake Titicaca) and the surrounding land. Some products (TMPA-3B42, PERSIANN and GSMaP) show a contradictory rainfall deficit over Lake Titicaca, which may be due to the emissivity contrast between the lake and the surrounding lands and warm rain cloud processes. An analysis differentiating coastal Lake Titicaca from inland pixels confirmed this trend. The raw or Real Time (RT) products have strong biases over the study region. These biases are strongly positive for PERSIANN (above 90%), moderately positive for TMPA-3B42 (28%), strongly negative for CMORPH (- 42%) and moderately negative for GSMaP (- 18%). The biases are associated with a deformation of the rain rate frequency distribution: GSMaP underestimates the proportion of rainfall events for all rain rates; CMORPH overestimates the proportion of rain rates below 2 mm day- 1; and the other products tend to overestimate the proportion of moderate to high rain rates. These biases are greatly reduced by the gauge adjustment in the TMPA-3B42, PERSIANN and CMORPH products, whereas a

  4. Erosion and deposition on the Pajarito Plateau, New Mexico, and implications for geomorphic responses to late Quaternary climatic changes

    Energy Technology Data Exchange (ETDEWEB)

    Reneau, S.L.; McDonald, E.V.; Gardner, J.N.; Longmire, P.A. [Los Alamos National Lab., NM (United States); Kolbe, T.R. [Woodward-Clyde Federal Services, Oakland, CA (United States); Carney, J.S. [Kent State Univ., OH (United States). Dept. of Geology; Watt, P.M. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences

    1996-04-01

    The Pajarito Plateau of northern New Mexico contains a rich and diverse record of late Quaternary landscape changes in a variety of geomorphic settings that include gently-sloping mesa tops, steep canyon walls, and canyon bottoms. A broad range of investigations during the past decade, motivated by environmental and seismic hazard concerns, have resulted in examination of the characteristics, stratigraphy, and age of sediments and soils at numerous locations throughout the Plateau. Geochronologic control is provided by >140 radiocarbon dates supplemented by soil characterization and tephrochronology. In this paper we first summarize some of the results of recent and ongoing work on late Quaternary deposits on the Pajarito Plateau, illustrating both the complexity of the geomorphic record and some common elements that have been observed in multiple locations. We then use these observations, in combination with other work in the Southwest, to make some inferences about the local geomorphic response to regional climatic changes. Because the geomorphic and paleoclimatic records are fragmentary, and because the relations between large scale climate changes and local variations in precipitation, vegetation, and geomorphic processes are not fully understood, many uncertainties exist concerning the response of the local landscape to past climatic fluctuations. In addition, variations in local landscape sensitivity related to prior erosional history and spatial variations in vegetation, and the localized nature of many storms, probably contribute to the complexity of the geomorphic record. Nevertheless, the work discussed in this paper suggests a strong relation between regional climatic changes and local geomorphic history, and provides a framework for considering relations between modem processes, the record of past landscape changes, and future erosion and deposition on the Plateau and in surrounding areas.

  5. The Standardized Candle Method for Type II Plateau Supernovae

    Science.gov (United States)

    Olivares E., Felipe; Hamuy, Mario; Pignata, Giuliano; Maza, José; Bersten, Melina; Phillips, Mark M.; Suntzeff, Nicholas B.; Filippenko, Alexei V.; Morrel, Nidia I.; Kirshner, Robert P.; Matheson, Thomas

    2010-06-01

    In this paper, we study the "standardized candle method" using a sample of 37 nearby (redshift z color curves, and velocity curves. We find that the V-I color toward the end of the plateau can be used to estimate the host-galaxy reddening with a precision of σ(AV ) = 0.2 mag. The correlation between plateau luminosity and expansion velocity previously reported in the literature is recovered. Using this relation and assuming a standard reddening law (RV = 3.1), we obtain Hubble diagrams (HDs) in the BVI bands with dispersions of ~0.4 mag. Allowing RV to vary and minimizing the spread in the HDs, we obtain a dispersion range of 0.25-0.30 mag, which implies that these objects can deliver relative distances with precisions of 12%-14%. The resulting best-fit value of RV is 1.4 ± 0.1.

  6. Mantle structure beneath the western edge of the Colorado Plateau

    Science.gov (United States)

    Sine, C.R.; Wilson, D.; Gao, W.; Grand, S.P.; Aster, R.; Ni, J.; Baldridge, W.S.

    2008-01-01

    Teleseismic traveltime data are inverted for mantle Vp and Vs variations beneath a 1400 km long line of broadband seismometers extending from eastern New Mexico to western Utah. The model spans 600 km beneath the moho with resolution of ???50 km. Inversions show a sharp, large-magnitude velocity contrast across the Colorado Plateau-Great Basin transition extending ???200 km below the crust. Also imaged is a fast anomaly 300 to 600 km beneath the NW portion of the array. Very slow velocities beneath the Great Basin imply partial melting and/or anomalously wet mantle. We propose that the sharp contrast in mantle velocities across the western edge of the Plateau corresponds to differential lithospheric modification, during and following Farallon subduction, across a boundary defining the western extent of unmodified Proterozoic mantle lithosphere. The deep fast anomaly corresponds to thickened Farallon plate or detached continental lithosphere at transition zone depths. Copyright 2008 by the American Geophysical Union.

  7. Frequency of human toxocariasis in Jos, Plateau State, Nigeria

    Directory of Open Access Journals (Sweden)

    OO Ajayi

    2000-04-01

    Full Text Available The enzyme-linked immunosorbent assay (Elisa was used to examine sera of 104 children and adults in Jos, Plateau State, Nigeria for anti-toxocaral antibodies, out of which 31 (29.8% were reactive. The seropositive rates were 30.4% for adults, 29.6% for children, 34% for females and 25.9% for males. However, the differences were not significant by age and sex. A highly significant association (p 0.05.

  8. Landslide development within the Barlad Plateau of Eastern Romania

    Science.gov (United States)

    Niacsu, Lilian; Ionita, Ion

    2014-05-01

    The Barlad Plateau, extending about 8,230 square kilometers is considered as the most typical unit of the Moldavian Plateau of the Eastern Romania. The Miocene-Pliocene clay-sandy layers are inter-bedded with shallow sandstone and limestone seams. These sedimentary layers that have outcropped as a result of erosion are gently dipping toward S-SE in the form of a monocline. Landslides have been recognized as an important environmental threat in the major subunits of the Barlad Plateau, namely: Central Moldavian Plateau, Falciu Hills and Tutova Rolling Hills. Four main areas of monitoring landslides were explored such as successive aerial photographs of the 1960, 1970, 2005 and 2009 flights, repeated field surveys for a thorough reconnaissance of the study area, classical levelling work and GIS software applications as TNT Mips and Arc GIS. Also, the Caesium-137 technique has been used to get information on documenting sedimentation rates in some small catchments. Results have indicated that the landslide development is strongly controlled by the northern and western looking steep faces of cuestas, by changes of rock composition and by human impact. Also, it showed great pulses in conjunction with the rainfall distribution. For example, half of the Upper Barlad catchment that drains an area of 22,560 ha is covered by landslides. Furthermore, the active landslides amounted 11% of the total (2,317 ha) after the rainy 1968-1973 period and since 1982 under drier conditions they gradually limited to 444.0 ha (2% of the total).

  9. Evaluating first-year pine seedling survival plateau in Louisiana

    Science.gov (United States)

    Puskar N. Khana; Thomas J. Dean; Scott D. Roberts; Donald L. Grebner

    2016-01-01

    First-year seeding survival has been a continuing problem since the start of commercial pine plantation forestry in the 1950s. First-year survival of bare-root loblolly pine seedlings on intensively prepared sites in Louisiana has maintained a survival plateau between 79 to 89 percent with an average of about 82 percent. The specific objectives of this study were to...

  10. The Colorado Plateau: cultural, biological, and physical research

    Science.gov (United States)

    Cole, Kenneth L.; van Riper, Charles

    2004-01-01

    Stretching from the four corners of Arizona, New Mexico, Colorado, and Utah, the Colorado Plateau is a natural laboratory for a wide range of studies. This volume presents 23 original articles drawn from more than 100 research projects presented at the Sixth Biennial Conference of Research on the Colorado Plateau. This scientific gathering revolved around research, inventory, and monitoring of lands in the region. The book's contents cover management techniques for cultural, biological, and physical resources, representing collaborative efforts among federal, university, and private sector scientists and land managers. Chapters on cultural concerns cover benchmarks of modern southwestern anthropological knowledge, models of past human activity and impact of modern visitation at newly established national monuments, challenges in implementing the 1964 Wilderness Act, and opportunities for increased federal research on Native American lands. The section on biological resources comprises sixteen chapters, with coverage that ranges from mammalian biogeography to responses of elk at the urban-wildland interface. Additional biological studies include the effects of fire and grazing on vegetation; research on bald eagles at Grand Canyon and tracking wild turkeys using radio collars; and management of palentological resources. Two final chapters on physical resources consider a proposed rerouting of the Rio de Flag River in urban Flagstaff, Arizona, and an examination of past climate patterns over the Plateau, using stream flow records and tree ring data. In light of similarities in habitat and climate across the Colorado Plateau, techniques useful to particular management units have been found to be applicable in many locations. This volume highlights an abundance of research that will prove useful for all of those working in the region, as well as for others seeking comparative studies that integrate research into land management actions.

  11. Research on the slope spectrum of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new concept dealing with digital analysis of loess terrain,slope spectrum,is presented and discussed in this paper,by introducing its characteristic,represen-tation and extracting method from DEMs. Using 48 geomorphological units in dif-ferent parts of the loess as test areas and 5 m-resolution DEMs as original test data,the quantitative depiction and spatial distribution of slope spectrum in China’s Loess Plateau have been studied on the basis of a series of carefully-designed experiments. In addition,initial experiment indicates a strong relationship between the slope spectrum and the loess landform types,displaying a potential importance of the slope spectrum in geomorphological studies. Based on the slope spectrums derived from the 25 m-resolution DEM data in whole loess terrain in northern part of Shaanxi,13 slope spectrum indices were extracted and integrated into a compre-hensive layer with image integration method. Based on that,a series of unsuper-vised classifications was applied in order to make a landform classification in northern Shaanxi Loess Plateau. Experimental results show that the slope spec-trum analysis is an effective method in revealing the macro landform features. A continuous change of slope spectrum from south to north in northern Shaanxi Loess Plateau shows an obvious spatial distribution of different loess landforms. This also proves the great significance of the slope spectrum method in describing the terrain roughness and landform evolution as well as a further understanding on landform genesis and spatial distribution rule of different landforms in the Loess Plateau.

  12. Effect of Vegetation Changes on Soil Erosion on the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fen-Li

    2006-01-01

    Vegetation is one of the key factors affecting soil erosion on the Loess Plateau. The effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from long-term field runoff plots established on the eastern slope of the Ziwuling secondary forest region, China and a field survey. The results showed that before the secondary vegetation restoration period (before about 1866-1872), soil erosion in the Ziwuling region of the Loess Plateau was similar to the current erosion conditions in neighboring regions, where the soil erosion rate now is 8 000 to 10 000t km-2 year-1. After the secondary vegetation restoration, soil erosion was very low; influences of rainfall and slope gradient on soil erosion were small; the vegetation effect on soil erosion was predominant; shallow gully and gully erosion ceased; and sediment deposition occurred in shallow gully and gully channels. In modern times when human activities destroyed secondary forests, soil erosion increased markedly, and erosion rates in the deforested lands reached 10 000 to24 000 t km-2 year-1, which was 797 to 1682 times greater than those in the forested land prior to deforestation. Rainfall intensity and landform greatly affected the soil erosion process after deforestation. These results showed that accelerated erosion caused by vegetation destruction played a key role in soil degradation and eco-environmental deterioration in deforested regions.

  13. Improvement of Rainfall Simulation on the Steep Edge of the Tibetan Plateau

    Science.gov (United States)

    Li, J.; Yu, R.; Zhang, Y.; Chen, H.

    2016-12-01

    Overestimation of precipitation over steep mountains has been a long-lasting bias in many climate models. After replacing the semi-Lagrangian method with a finite-difference approach for trace transport algorithm (the two-step shape preserving scheme, TSPAS), the modified NCAR CAM5 (M-CAM5) with high horizontal resolution results in a significant improvement of simulation in precipitation over the steep edge of the Tibetan Plateau. The M-CAM5 restrains the "overshoot" of water vapor to the high-altitude region of the windward slopes and significantly reduces the overestimation of precipitation in areas above 2000 m along the southern edge of the Tibetan Plateau. More moisture are left in the low-altitude region on the slope where used to present dry biases in CAM5. The excessive (insufficient) amount of precipitation over the higher (lower) part of the steep slope is partially caused by the multi-grid water vapor transport in CAM5, which leads to spurious accumulation of water vapor at cold and high-altitude grids. Benefited from calculation of transport grid by grid in TSPAS and detailed description of steep mountains by the high-resolution model, M-CAM5 moves water vapor and precipitation downward over windward slopes and presents a more realistic simulation. Results in this study indicate that in addition to the development of physical parameterization schemes, the dynamical process should also be reconsidered in order to improve the climate simulation over steep mountains.

  14. Estimation of actual evapotranspiration in the Nagqu river basin of the Tibetan Plateau

    Science.gov (United States)

    Zou, Mijun; Zhong, Lei; Ma, Yaoming; Hu, Yuanyuan; Feng, Lu

    2017-05-01

    As a critical component of the energy and water cycle, terrestrial actual evapotranspiration (ET) can be influenced by many factors. This study was mainly devoted to providing accurate and continuous estimations of actual ET for the Tibetan Plateau (TP) and analyzing the effects of its impact factors. In this study, summer observational data from the Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau (CAMP/Tibet) for 2003 to 2004 was selected to determine actual ET and investigate its relationship with energy, hydrological, and dynamical parameters. Multiple-layer air temperature, relative humidity, net radiation flux, wind speed, precipitation, and soil moisture were used to estimate actual ET. The regression model simulation results were validated with independent data retrieved using the combinatory method. The results suggested that significant correlations exist between actual ET and hydro-meteorological parameters in the surface layer of the Nagqu river basin, among which the most important factors are energy-related elements (net radiation flux and air temperature). The results also suggested that how ET is eventually affected by precipitation and two-layer wind speed difference depends on whether their positive or negative feedback processes have a more important role. The multivariate linear regression method provided reliable estimations of actual ET; thus, 6-parameter simplified schemes and 14-parameter regular schemes were established.

  15. Is the Mozambique Ridge related to the Agulhas Plateau Large Igneous Province?

    Science.gov (United States)

    Gohl, K.; Uenzelmann-Neben, G.; Parsiegla, N.

    2009-12-01

    The Mozambique Ridge (MOZR) and the Agulhas Plateau (AP) are prominent bathymetrically elevated rises off south-eastern Africa connected by a rise of less bathymetric expression. Intuitively, this observation would imply that the plateaus and rises underwent a related crustal formation. Deep crustal ocean-bottom seismometer data and a multichannel seismic reflection profile from the southern MOZR show evidence for its predominantly oceanic crustal origin with excessive volcanic eruption and magmatic accretion phases. The lower two-thirds of the crustal column exhibit P-wave velocities of more than 7.0 km/s, increasing to 7.5-7.6 km/s at the crustal base. These velocities suggest that the lower crust was accreted by large volumes of mantle-derived material to form an over-thickened equivalent of an oceanic layer 3. When comparing the velocity-depth model and the observations of the seismic reflection data with those of the AP, a resemblance can be established which concludes that a greater Southeast African Large Igneous Province (LIP) must have formed between 140 and 95 Ma in phases of highly varying magmatic and volcanic activities. The timing, size and formation history of the Southeast African LIP is almost analog to that of the Kerguelen-Heard Plateau, which provokes speculation about related processes of periodic magma generation at that time.

  16. Spatial-Temporal Patterns and Controls of Evapotranspiration across the Tibetan Plateau (2000–2012

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-01-01

    Full Text Available Evapotranspiration (ET is a key factor to further our understanding of climate change processes, especially on the Tibetan Plateau, which is sensitive to global change. Herein, the spatial patterns of ET are examined, and the effects of environmental factors on ET at different scales are explored from the years 2000 to 2012. The results indicated that a steady trend in ET was detected over the past decade. Meanwhile, the spatial distribution shows an increase of ET from the northwest to the southeast, and the rate of change in ET is lower in the middle part of the Tibetan Plateau. Besides, the positive effect of radiation on ET existed mainly in the southwest. Based on the environment gradient transects, the ET had positive correlations with temperature (R>0.85, p 0.89, p 0.75, p < 0.0001, but a negative correlation between ET and radiation (R = 0.76, p < 0.0001 was observed. We also found that the relationships between environmental factors and ET differed in the different grassland ecosystems, which indicated that vegetation type is one factor that can affect ET. Generally, the results indicate that ET can serve as a valuable ecological indicator.

  17. Lake volume and groundwater storage variations in Tibetan Plateau's endorheic basin

    Science.gov (United States)

    Zhang, Guoqing; Yao, Tandong; Shum, C. K.; Yi, Shuang; Yang, Kun; Xie, Hongjie; Feng, Wei; Bolch, Tobias; Wang, Lei; Behrangi, Ali; Zhang, Hongbo; Wang, Weicai; Xiang, Yang; Yu, Jinyuan

    2017-06-01

    The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing cryospheric-hydrologic-geodynamic processes, is particularly sensitive to anthropogenic warming. The quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level, and volume during 1970s-2015. We find that a complex pattern of lake volume changes during 1970s-2015: a slight decrease of -2.78 Gt yr-1 during 1970s-1995, followed by a rapid increase of 12.53 Gt yr-1 during 1996-2010, and then a recent deceleration (1.46 Gt yr-1) during 2011-2015. We then estimated the recent water mass budget for the Inner TP, 2003-2009, including changes in terrestrial water storage, lake volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components of water mass budget, namely, changes in lake volume (7.72 ± 0.63 Gt yr-1) and groundwater storage (5.01 ± 1.59 Gt yr-1), increased at similar rates. We find that increased net precipitation contributes the majority of water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due to permafrost degradation (12%). Other term such as SWE (1%) makes a relatively small contribution. These results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

  18. Synthesis under Microwave Irradiation and Crystal Structure of 4-(3,4-Methylenedioxylphenyl)-6-methyl- 5-ethoxycaronyl-3,4-dihydropyrimidin-2(H)-one

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Jiang; FANG Fang; JIANG Hong; ZHU Song-Lei; LI Tuan-Jie; ZHANG Xiao-Jing; SHI Da-Qing

    2004-01-01

    The title compound 4-(3,4-methylenedioxylphenyl)-6-methyl-5-ethoxycaronyl-3,4- dihydropyrimidin-2(H)-one (C15H16N2O5) has been synthesized and determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group Pī with a = 7.580(1), b = 7.920(2), c = 13.168(4)(A。),α = 96.44(2),β = 96.71(2), γ = 109.81(2)°, V = 728.8(3) (A。)3, Z = 2, Mr = 304.30, Dc = 1.387 g/cm3, F(000) = 320, μ(MoKα) = 0.105 mm-1 (λ = 0.71073(A。)), R = 0.0446 and wR = 0.1205. In the molecule the pyrimidine ring adopts a boat conformation.

  19. Inhibition of Na(+)/K(+)-ATPase by 5,6,7,8-tetrafluoro-3-hydroxy-2-phenylquinolin-4(1H)-one.

    Science.gov (United States)

    Šeflová, Jaroslava; Čechová, Petra; Biler, Michal; Hradil, Pavel; Kubala, Martin

    2017-07-01

    Na(+)/K(+)-ATPase (NKA) is an enzyme of crucial importance for all animal cells. We examined the inhibitory effects of halogenated phenylquinolinones on NKA. The 5,6,7,8-tetrafluoro-3-hydroxy-2-phenylquinolin-4(1H)-one (TFHPQ) was identified as an efficient NKA inhibitor with IC50 near 10 μM. The inhibition by TFHPQ is particularly efficient at higher concentrations of K(+), where NKA adopts the E2 conformation. The experimental observations are in a good agreement with the outcomes from molecular docking. We identified an energetically favourable TFHPQ binding site for the K(+)-bound NKA, which is located in the proximity of the cytoplasmic C-terminus. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. A new 2-(2‧-hydroxyphenyl)quinazolin-4(3H)-one derived acylhydrazone for fluorescence recognition of Al3 +

    Science.gov (United States)

    Tang, Lijun; Ding, Shuangli; Zhong, Keli; Hou, Shuhua; Bian, Yanjiang; Yan, Xiaomei

    2017-03-01

    A new 2-(2‧-hydroxyphenyl)quinazolin-4(3H)-one derived acylhydrazone (QP) was designed and synthesized as a fluorescent sensor. In Tris • HCl buffer (10 mM, pH 7.4)/ethanol (1/9, v/v) solution, QP exhibits a highly selective fluorescence response to Al3 + over other metal ions with a significant blue-shifted and enhanced emission at 473 nm. QP interacts with Al3 + reversibly through a 1:2 binding ratio with a detection limit of 4.79 × 10- 8 M. Potential applicability of QP for Al3 + detection in tap and lake water samples were also examined by 'proof-of-concept' experiments.

  1. Potent and selective HIV-1 ribonuclease H inhibitors based on a 1-hydroxy-1,8-naphthyridin-2(1H)-one scaffold.

    Science.gov (United States)

    Williams, Peter D; Staas, Donnette D; Venkatraman, Shankar; Loughran, H Marie; Ruzek, Rowena D; Booth, Theresa M; Lyle, Terry A; Wai, John S; Vacca, Joseph P; Feuston, Bradley P; Ecto, Linda T; Flynn, Jessica A; DiStefano, Daniel J; Hazuda, Daria J; Bahnck, Carolyn M; Himmelberger, Amy L; Dornadula, Geetha; Hrin, Renee C; Stillmock, Kara A; Witmer, Marc V; Miller, Michael D; Grobler, Jay A

    2010-11-15

    Optimization studies using an HIV RNase H active site inhibitor containing a 1-hydroxy-1,8-naphthyridin-2(1H)-one core identified 4-position substituents that provided several potent and selective inhibitors. The best compound was potent and selective in biochemical assays (IC(50)=0.045 μM, HIV RT RNase H; 13 μM, HIV RT-polymerase; 24 μM, HIV integrase) and showed antiviral efficacy in a single-cycle viral replication assay in P4-2 cells (IC(50)=0.19 μM) with a modest window with respect to cytotoxicity (CC(50)=3.3 μM).

  2. Naturally Abundance Vanillin as Starting Material to Synthesizing 4-(4-Hydroxy-3-methoxyphenyl-6-methyl-3,4-dihydropyrimidin-2(1H-one

    Directory of Open Access Journals (Sweden)

    Masruri MASRURI

    2015-12-01

    Full Text Available Indonesia is the second biggest producer of natural vanillin. Traditionally it was isolated from the bean of vanilla (Vanilla planifolia Andrews. This paper reports on applying vanillin as starting material for synthesizing a biologically important chemical structure 3,4-dihydropyrimidinone. The reaction was undertaken in one step following multi component reaction (MCR. Products determination was undergone using FTIR and UV-Vis spectrophotometry, and also liquid chromatography-mass spectrometry (LCMS. After purification under flash column chromatography in ethyl acetate-hexane, it was found a white solid of 4-(4-hydroxy-3-methoxyphenyl-6-methyl-3,4-dihydropyrimidin-2(1H-one in 67% yield with a few amount of an unreacted vanillin.

  3. Formation of allenyl ketones, 3-ethynylcoumarins, and arylfurans, furylfurans, and furylthiophenes by flash vacuum thermolysis of 3-methylidenefuran-2(3H)-ones.

    Science.gov (United States)

    Koch, Rainer; Berstermann, Hans Michael; Wentrup, Curt

    2014-01-03

    Flash vacuum thermolysis (FVT) of 3-methylidenefuran-2(3H)-ones 3 causes cheletropic extrusion of CO with formation of allenyl ketones 4. o-Chloro- and o-bromophenylmethylidenefuranones also afford allenyl ketones upon flash vacuum thermolysis, but in addition, 3-ethynylcoumarins 6 are formed via E/Z isomerization of the methylidenefuranones, cyclization, halogen atom migration, and HCl (HBr) elimination. The presence of strongly electron-withdrawing groups (nitroaryl or acetyl) on the acylallene moiety causes rearrangement to give 2-arylfurans 10 and 13 as well as 2-furylfurans and 2-furylthiophenes 16 by cyclization of the allenyl ketones. The reaction mechanisms are supported by calculations at the M06-2X/6-311+G(d,p) level of theory.

  4. Synthesis and Antitumor Evaluation of Novel 5-Hydrosulfonyl-1H-benzo[d]imidazol-2(3H)-one Derivatives.

    Science.gov (United States)

    Ouyang, Guang; Tong, Rongsheng; Li, Jinqi; Bai, Lan; Ouyang, Liang; Duan, Xingmei; Li, Fengqiong; He, Pin; Shi, Jianyou; He, Yuxin

    2016-04-20

    A series of novel 5-hydrosulfonyl-1H-benzo[d]imidazol-2(3H)-one derivatives bearing natural product substructures has been successfully synthesized and their antitumor activity studied. These newly synthesized derivatives were characterized by ¹H-NMR, (13)C-NMR and high resolution mass spectral data, then screened as antitumor agents against the A549, HCC1937, and MDA-MB-468 human tumor cell lines using MTT cell proliferation assays. The results show that some of these compounds can effectively inhibit the growth of these cancerous cells, with compound 5b being the best one (IC50 = 2.6 μM). Flow cytometry data revealed that compound 5b induced apoptosis of HCC1937 cells with increased solution concentration. The structure and activity relationships (SAR) of these compounds is summarized.

  5. Synthesis and Antitumor Evaluation of Novel 5-Hydrosulfonyl-1H-benzo[d]imidazol-2(3H-one Derivatives

    Directory of Open Access Journals (Sweden)

    Guang Ouyang

    2016-04-01

    Full Text Available A series of novel 5-hydrosulfonyl-1H-benzo[d]imidazol-2(3H-one derivatives bearing natural product substructures has been successfully synthesized and their antitumor activity studied. These newly synthesized derivatives were characterized by 1H-NMR, 13C-NMR and high resolution mass spectral data, then screened as antitumor agents against the A549, HCC1937, and MDA-MB-468 human tumor cell lines using MTT cell proliferation assays. The results show that some of these compounds can effectively inhibit the growth of these cancerous cells, with compound 5b being the best one (IC50 = 2.6 μM. Flow cytometry data revealed that compound 5b induced apoptosis of HCC1937 cells with increased solution concentration. The structure and activity relationships (SAR of these compounds is summarized.

  6. Synthesis and SAR of 1-Hydroxy-1H-benzo[d]imidazol-2(3H)-ones as Inhibitors of d-Amino Acid Oxidase

    Science.gov (United States)

    2012-01-01

    A series of 1-hydroxy-1H-benzo[d]imidazol-2(3H)-ones were synthesized and evaluated for their ability to inhibit human and porcine forms of d-amino acid oxidase (DAAO). The inhibitory potency is largely dependent on the size and position of substituents on the benzene ring with IC50 values of the compounds ranging from 70 nM to greater than 100 μM. Structure–activity relationships of this new class of DAAO inhibitors will be presented in detail along with comparisons to previously published SAR data from other classes of DAAO inhibitors. Two of these compounds were given to mice orally together with d-serine to assess their effects on plasma d-serine pharmacokinetics. PMID:23243487

  7. Indium Titanium Oxide Nanoparticles Induced Hepatic Damage: Hepatoprotective Role of Novel 2-Imino-4-methyl-1, 2-Dihydropyrimido [5, 4C] Quinoline-5(6H-one

    Directory of Open Access Journals (Sweden)

    Dinesh Bheeman

    2014-01-01

    Full Text Available Protective role of 2-imino-4-methyl-1, 2-dihydropyrimido [5, 4C] quinoline-5(6H-one (IMDHPQ in indium titanium oxide nanoparticles (InTiO NPs induced hepatotoxicity was analyzed. InTiO NPs were synthesized and given orally to albino rats to assess their hepatotoxicity. NPs mediated oxidative stress and liver tissue pathology were analyzed. Altered antioxidants (GSH, GPx, and catalase and, biochemical (SGOT, SGPT, ALP, total protein, and total bilirubin and histopathological changes were observed due to the oxidative stress caused by InTiO NPs. Varying effects of IMDHPQ on each parameter were observed in the present study. The altered parameters of InTiO NPs exposed rats might be due to the oxidative stress caused by NPs and hepatoprotective or ameliorative efficacy of quinoline compound IMDHPQ on signaling and molecular mechanism needs further study.

  8. Design and synthesis of novel tetrahydro-2H-Pyrano[3,2-c]pyridazin-3(6H)-one derivatives as potential anticancer agents.

    Science.gov (United States)

    Al-Tel, Taleb H

    2010-12-01

    Polyfunctional tetrahydro-2H-pyrano[3,2-c]pyridazin-3(6H)-one derivatives were synthesized and biologically evaluated as novel anticancer agents. These motifs were produced by a five-step reaction sequence in which the Achmatowicz oxidative cyclization, is the basic core for such synthesis. Compounds 15f, 16c, and 16d showed antiproliferative activity against the SK-BR-3 breast cancer cell line. Importantly, 16c and 16d showed the highest efficacy, being approximately 30-fold more potent against SK-BR-3 (IC50 0.21 and 0.15 μM, respectively) compared to other cancer cell lines tested. In addition, 16c and 16d displayed about 295 fold less toxicity against normal breast cell line MCF10A compared to SK-BR-3 breast cancer cells. These compounds form the foundation for further investigation in our continuing efforts to develop potent anticancer agents.

  9. Synthesis, Structure Characterization, and Cu2+ Recognition of 3-{[3-(Phenylsulfonamido)benzoyl]methylidene}-3,4-dihydroquinoxaline-2(1H)-one

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Aryl diketo acid derivatives are one of the most promising HIV-1 integrase(IN) inhibitors. With a view to substitute the critical diketo acid pharmacophore with the diketo benzimidazole unit, the coupling reaction of compound 4 with o -phenylenediamine was carried out. However, the reaction product, compound 5, was confirmed to be 3-{[3-(phenylsulfonamido)benzoyl]methylidene}-3,4-dihydroquinoxaline-2(1H)-one rather than the2-benzimidazole derivative by using X-ray diffraction. Owing to its low solubility in water, the evaluation of the anti-HIV IN activity of the synthesized compound 5 could not be carried out. Consequently, the ion-binding properties of compound 5 in the absence of HIV-1 IN were investigated with UV-Vis spectroscopy in organic solvents. The results show that such a compound can selectively recognize Cu2+ .

  10. Novel 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3Hone-6-sulphonic acidbased mono azo reactive dyes

    Directory of Open Access Journals (Sweden)

    DIVYESH R. PATEL

    2011-02-01

    Full Text Available A series of new heterocyclic mono azo reactive dyes 7a–m were prepared by diazotization of 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3H-one-6-sulphonic acid (3 and coupling with various cyanurated coupling components 6a–m and their dyeing performance on silk, wool and cotton fibres was assessed. These dyes were found to give a variety of colour shades with very good depth and levelness on the fibres. All the compounds were identified by conventional method (IR and 1H-NMR and elemental analyses. The percentage dye bath exhaustion on different fibres was reasonably good and acceptable. The dyed fibre showed moderate to very good fastness to light, washing and rubbing.

  11. Design and synthesis of novel benzo[d]oxazol-2(3H)-one derivatives bearing 7-substituted-4-enthoxyquinoline moieties as c-Met kinase inhibitors.

    Science.gov (United States)

    Lu, Dong; Shen, Aijun; Liu, Yang; Peng, Xia; Xing, Weiqiang; Ai, Jing; Geng, Meiyu; Hu, Youhong

    2016-06-10

    Analysis of the results of studies of docking 1 and 7a with c-Met kinase led to the identification of benzo[d]oxazol-2(3H)-one-quinolone derivatives as potential inhibitors of this enzyme. A molecular hybrid strategy, using a 4-ethoxy-7-substituted-quinoline core and a benzo[d]oxazol-2(3H)-one scaffold, was employed to design members of this family for study as inhibitors of the kinase and proliferation of EBC-1 cells. Most of the substances were found to display good to excellent c-Met kinase inhibitory activities. The results of a structure-activity relationship (SAR) study led to the discovery of benzo[d]oxazol-2(3H)-one-quinolone 13, which has IC50 values of 1 nM against c-Met kinase and 5 nM against proliferation of the EBC-1 cell line.

  12. Synthesis and Crystal Structure of 1-(4-Nitrobenzyl-3-allyl-1H-benzo[d]imidazol-2(3H-one

    Directory of Open Access Journals (Sweden)

    Dounia Belaziz

    2013-01-01

    Full Text Available A functionalized benzimidazole, 1-(4-nitrobenzyl-3-allyl-1H-benzo[d]imidazol-2(3H-one, has been synthesized, and the crystal structure was determined and analyzed. This compound crystallizes in the monoclinic, space group P21/n (number 14 c with cell parameters, a=7.12148(8 Å, b=16.12035(17 Å, c=13.04169(17 Å, β=93.3043(11, V=1494.71(3 Å3, and Dcalc = 1.375 g/mm3. The solid state geometry is stabilized by intermolecular π–π interactions along with the van der Waals interactions which contribute to the stability of the crystal packing. Computational calculations have been used to properly understand the main intermolecular interactions present in the crystal.

  13. Extremely strong temperature-dependent Davydow-splitting effects in the polarized IR spectra of the hydrogen bond: Pyrazole and quinolin-2(1H)-one crystals

    Science.gov (United States)

    Hachuła, Barbara; Flakus, Henryk T.; Tyl, Aleksandra; Polasz, Anna

    2014-04-01

    Polarized IR spectra were recorded in the spectral range of the νN-H and νN-D proton stretching vibration bands for the isotopically neat and isotopically diluted crystals of pyrazole (Pzl) and quinolin-2(1H)-one (2HQ). The spectra measured in the temperature range of 77-293 K have shown that temperature extremely strongly influenced the magnitude of the Davydow-splitting effects in the crystalline spectra. Two different competing vibrational Davydow-coupling mechanisms involving hydrogen bonds, i.e., the ‘tail-to-head' and the ‘side-to-side', were responsible for the generation of the temperature effects in the polarized spectra.

  14. Stability of alpine meadow ecosystem on the Qinghai- Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    ZHOU Huakun; ZHOU Li; ZHAO Xinquan; LIU Wei; LI Yingnian; GU Song; ZHOU Xinmin

    2006-01-01

    The meadow ecosystem on the Qinghai-Tibetan Plateau is considered to be sensitive to climate change. An understanding of the alpine meadow ecosystem is therefore important for predicting the response of ecosystems to climate change. In this study, we use the coefficients of variation (Cv) and stability (E) obtained from the Haibei Alpine Meadow Ecosystem Research Station to characterize the ecosystem stability. The results suggest that the net primary production of the alpine meadow ecosystem was more stable (Cv = 13.18%) than annual precipitation (Cv = 16.55%) and annual mean air temperature (Cv = 28.82%). The net primary production was insensitive to either the precipitation (E = 0.0782) or air temperature (E = 0.1113). In summary, the alpine meadow ecosystem on the Qinghai- Tibetan Plateau is much stable. Comparison of alpine meadow ecosystem stability with other five natural grassland ecosystems in Israel and southern African indicates that the alpine meadow ecosystem on the Qinghai-Tibetan Plateau is the most stable ecosystem. The alpine meadow ecosystem with relatively simple structure has high stability, which indicates that community stability is not only correlated with biodiversity and community complicity but also with environmental stability. An average oscillation cycles of 3―4 years existed in annual precipitation, annual mean air temperature, net primary production and the population size of consumers at the Haibei natural ecosystem. The high stability of the alpine meadow ecosystem may be resulting also from the adaptation of the ecosystem to the alpine environment.

  15. Several characteristics of contemporary climate change in the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    朱文琴; 陈隆勋; 周自江

    2001-01-01

    Characteristics of contemporary climate change in the Tibetan Plateau have been investigated based on the observational data of monthly mean air temperature, monthly mean maximum and minimum air temperatures, and precipitation amount at 217 stations in the Plateau and its adjacent areas in 1951-1998, in which the temperature data at Lhasa, Lanzhou, Kunming and Chengdu were extended to a period of 1935-1950. The following conclusions can be drawn. (1) The air temperature in the Tibetan Plateau decreased from the 1950s to the 1960s, afterwards it began warming up to the 1990s. The data at the Lhasa Station beginning from 1935 have indicated that the air temperature at the station was the highest in the 1940s, then it became cooling until the 1960s. After the 1960s, it began warming until the 1990s. However, the air temperature at Lhasa in the 1990s still did not reach as high as in the 1940s. (2) Since the 1960s, there has existed a cooling belt below 3000 m altitude above sea level, which is located in ea

  16. Soil Erosion Study on the Chinese Loess Plateau

    Science.gov (United States)

    Hu, Yaxian; Guo, Shengli; Kuhn, Nikolaus

    2017-04-01

    The Chinese Loess Plateau, because of its highly erodible loess soils and hilly topography, has been extensively studied by soil scientists and geomorphologists. As a research hotspot, there are five national-level field stations across the Loess Plateau, with hundreds of erosion plots set up with various sizes, lengths, slope angles and vegetation covers. In addition, huge indoor rain simulation facilities exist in in different institutes which can provide rainfall simulations under a wide range of controlled conditions. Consequently, national-level restoration projects have achieved tremendous improvements in curbing soil erosion and improving regional agro-ecosystem, mostly by afforestation and soil rehabilitation. However, when implementing the advanced techniques and models that have been widely applied in the rest of the world, there are often regional considerations, which demand new approaches to overcome. One example are the unintentional impacts of restoration efforts, such as the establishment of apple orchards. Over 20 years, they have caused an increase in soil erodibility and lowered local ground water levels. Neither before the introduction of this landscape rehabilitation technique, nor now, has the impact of intensive fruit production been systematically studied, despite lending itself to systematic experiments. The lack of research is attributed to the general idea that trees protect soils and improve environmental services. This presentation identifies several such specific regional environmental issues associated with soil erosion on the Loess Plateau and discusses strategies to avoid missing important research questions.

  17. Spatial variation of reference crop evapotranspiration on Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Yong-hong YANG; Zhan-yu ZHANG; Xin-yi XIANG

    2009-01-01

    This study is based on meteorological observation data collected at 38 weather stations on the Tibetan Plateau over several decades. Daily reference crop evapotranspiration (ET0) was calculated with the FAO-56 standard Penman-Monteith formula. A test of normality was performed with Statistica 6.0 software, isotropic and anisotropic semi-variogram analysis was conducted with the GS+ (geostatistics for the environmental sciences) system for Windows 7.0, and the characteristics of spatial variation of daily ET0 were obtained. The following results can be obtained: Daily ETo for different periods on the Tibetan Plateau are distributed normally; Except for daily ETo in the E-W (east-west) direction in the summer, which showed a slight negative correlation with distance change, the Moran's indexes of daily ET0 for different periods in all directions on the Tibetan Plateau within a 100-km distance were positive, demonstrating a positive correlation with distance change; Variograms of daily ET0 in June, the dry season, the wet season, as well as annual average daily ET0 fit well with the Gaussian model; A variogram of daily ET0 in December fit well with the exponential model; Variograms of daily ET0 for the four seasons fit well with the linear with sill model.

  18. Plateau Inflation in $R$-parity Violating MSSM

    CERN Document Server

    Chakravarty, Girish Kumar; Lambiase, Gaetano; Mohanty, Subhendra

    2016-01-01

    Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical K\\"ahler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry at the end of the inflation. The SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and triliear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.

  19. Path of Social Construction in Northwest Sichuan Plateau Pastoral Area

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    On the basis of main contents of social construction and key points of construction,this paper analyzes features of conditions of northwest Sichuan plateau pastoral area.The social construction at current stage mainly includes social cause in narrow sense,and social management at meso-level.The northwest Sichuan plateau pastoral area is faced with the best policy and development opportunity.However,there are still many weak aspects.Firstly,social structure is not coordinated with economic structure.Secondly,social construction ability of grass-roots government is weak.Thirdly,the ability to respond to public demands is low.Fourthly,there is a big gap in availability of basic public service.Finally,it presents path selection for social construction of northwest Sichuan plateau pastoral area:strengthen social construction ability of grass-roots government;promote social construction with livelihood projects as key projects;boost social construction taking advantage of ecological construction;develop basic public service with the aid of external forces;intensify evaluation system for supervision of social construction works.

  20. River discharge changes in the Qinghai-Tibet Plateau

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Annual mean discharge data of the five large rivers in the exorheic region of the Qinghai-Tibet Plateau from 1956 to 2000 are analyzed for trends with the Mann-Kendall nonparametric trend test. The results reveal that though in general no increasing trends exist in the total river discharges, significant regional differences of river discharge exist, reflecting the decreasing trends of discharge in the Yellow River and the Tongtian River (upper Changjiang River), an increasing trend in Yalong River, and inverted change in the Lancang River and Yarlung Zangbo River. Based on analyses of the seasonal discharge, it is found that climatic change had a significant effect on the seasonal variation of river discharge in the Qinghai-Tibet Plateau. In spring (from March to May) the discharge increased significantly, especially in the source area of the Yellow River. Together with the analyses on data of the mean temperature in the Northern Hemisphere and climatic data within the river basins, the relationship between discharges and mean temperature of the Northern Hemisphere is explored, which indicates that there is no increase in the stream discharge in the Qinghai-Tibet Plateau with global warming. It is probably the increasing evaporation, caused by rising temperature that offsets the hydrological effect of increasing precipitation.