Sample records for reaction coordinate ca-cl

  1. Quasiclassical trajectory and wave packet calculations for D + CaCl(X2Σ+; vi = 0, ji = 0) → DCl + Ca(1S) reaction

    Tan, Rui Shan; Yan, Wei; Lin, Shi Ying


    A computational study for the title reaction is carried out employing recent ab initio potential energy surface. J = 0 reaction probability is obtained using both quasiclassical trajectory (QCT) and wave packet methods. The total and state resolved integral as well as differential cross sections are also obtained by means of QCT method. Dynamics of the title reaction shows qualitative similarity with its isotopic counterpart, the H + CaCl reaction, but quantitatively, reactivity is significantly enhanced in the title reaction. In addition, the effect of initial rotational state excitation on H + CaCl reaction is investigated.

  2. Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2


    The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps.The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3,Ca5F(PO4)3 and Ca3(PO4)2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3decomposing has high chemical activity. In calcining process, the new formed Ca5F(PO4)3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.

  3. Quantum and classical dynamics of H + CaCl(X (2)Σ(+)) → HCl + Ca((1)S) reaction and vibrational energy levels of the HCaCl complex.

    Tan, Rui Shan; Zhai, Huan Chen; Gao, Feng; Tong, Dianmin; Lin, Shi Ying


    We carried out accurate quantum wave packet as well as quasi-classical trajectory (QCT) calculations for H + CaCl (νi = 0, ji = 0) reaction occurring on an adiabatic ground state using the recent ab initio potential energy surface to obtain the quantum and QCT reaction probabilities for several partial waves (J = 0, 10, and 20) as well as state resolved QCT integral and differential cross sections. The complete list of vibrational energy levels supported by the intermediate HCaCl complex is also obtained using the Lanczos algorithm. The QCT reaction probabilities show excellent agreement with the quantum ones except for the failure in reproducing the highly oscillatory resonance structure. Despite the fact that the reaction is exothermic and the existence of a barrier that is energetically lower than the bottom of the reactant valley, the reaction probability for J = 0 shows threshold-like behavior and the reactivity all through the energies is very low (0.35 eV) are found to be different drastically from each other. The analyses of these results suggest that the reaction is governed by one of the two different types of reaction mechanism, one is the direct mechanism at the high energy region and the other is the indirect mechanism at the low energy region by which the reaction proceeds through the long-lived intermediate complex followed by a statistical dissociation into asymptotic channels.

  4. The Formation of Mathematical Model for CaCl2 Derived from The Reaction of Ulexite and Hydrochloric Acid by Using Full Factorial Desing Method

    DURAK, Halil; GENEL, Yasar; BASHIROV, Novruz; KERIMOV, Genber


    One of the significant boron compounds which are common substance in nature is ulexite. Ulexite is a sodium calcium boron hydrate, its chemical formula is Na2O2CaO5B2O316H2O , and it is thick with in Turkey. Lots of products are derived from boron minerals. One of them is boric acid. CaCl2 is used in many fields and this compound can be obtained by different processes. The aim of this study is producing CaCl2 by forming mathematical model for CaCl2 composing in the wake of the interaction of ...

  5. The Formation of Mathematical Model for CaCl2 Derived from The Reaction of Ulexite and Hydrochloric Acid by Using Full Factorial Desing Method

    DURAK, Halil; GENEL, Yasar; BASHIROV, Novruz; KERIMOV, Genber


    One of the significant boron compounds which are common substance in nature is ulexite. Ulexite is a sodium calcium boron hydrate, its chemical formula is Na2O2CaO5B2O316H2O , and it is thick with in Turkey. Lots of products are derived from boron minerals. One of them is boric acid. CaCl2 is used in many fields and this compound can be obtained by different processes. The aim of this study is producing CaCl2 by forming mathematical model for CaCl2 composing in the wake of the interaction of ...

  6. Reaction Coordinates and Mechanistic Hypothesis Tests.

    Peters, Baron


    Reaction coordinates are integral to several classic rate theories that can (a) predict kinetic trends across conditions and homologous reactions, (b) extract activation parameters with a clear physical interpretation from experimental rates, and (c) enable efficient calculations of free energy barriers and rates. New trajectory-based rare events methods can provide rates directly from dynamical trajectories without a reaction coordinate. Trajectory-based frameworks can also generate ideal (but abstract) reaction coordinates such as committors and eigenfunctions of the master equation. However, rates and mechanistic insights obtained from trajectory-based methods and abstract coordinates are not readily generalized across simulation conditions or reaction families. We discuss methods for identifying physically meaningful reaction coordinates, including committor analysis, variational transition state theory, Kramers-Langer-Berezhkovskii-Szabo theory, and statistical inference methods that can use path sampling data to screen, mix, and optimize thousands of trial coordinates. Special focus is given to likelihood maximization and inertial likelihood maximization approaches.

  7. Reaction Coordinates and Mechanistic Hypothesis Tests

    Peters, Baron


    Reaction coordinates are integral to several classic rate theories that can (a) predict kinetic trends across conditions and homologous reactions, (b) extract activation parameters with a clear physical interpretation from experimental rates, and (c) enable efficient calculations of free energy barriers and rates. New trajectory-based rare events methods can provide rates directly from dynamical trajectories without a reaction coordinate. Trajectory-based frameworks can also generate ideal (but abstract) reaction coordinates such as committors and eigenfunctions of the master equation. However, rates and mechanistic insights obtained from trajectory-based methods and abstract coordinates are not readily generalized across simulation conditions or reaction families. We discuss methods for identifying physically meaningful reaction coordinates, including committor analysis, variational transition state theory, Kramers-Langer-Berezhkovskii-Szabo theory, and statistical inference methods that can use path sampling data to screen, mix, and optimize thousands of trial coordinates. Special focus is given to likelihood maximization and inertial likelihood maximization approaches.

  8. Extraction of potassium from K-feldspar via the CaCl2 calcination route☆

    Bo Yuan; Chun Li; Bin Liang; Li Lü; Hairong Yue; Haoyi Sheng; Longpo Ye; Heping Xie


    The extraction of potassium from K-feldspar via a calcium chloride calcination route was studied with a focus on the effects of the calcination atmosphere, calcination temperature and time, mass ratio of CaCl2 to K-feldspar ore and particle size of the K-feldspar ore. The results demonstrated that a competing high-temperature hydrolysis reaction of calcium chloride with moisture in a damp atmosphere occurred concurrently with the conversion reaction of K-feldspar with CaCl2, thus reducing the amount of potassium extracted. The conversion reaction started at approximately 600 °C and accelerated with increasing temperature. When the temperature rose above 900 °C, the extraction of potassium gradually decreased due to the volatilization of the product, KCl. As much as approximately 41%of the potassium was volatilized in 40 min at 1100 °C. The mass ratio of CaCl2/K-feldspar ore significantly affected the extraction. At a mass ratio of 1.15 and 900 °C, the potassium extraction reached 91%in 40 min, while the extraction was reduced to only 22%at the theoretical mass ratio of 0.2. Optimal process conditions are as follows:ore particle size of 50–75μm, tablet forming pressure of 3 MPa, dry nitrogen atmosphere, mass ratio of CaCl2/ore 1.15:1, calcination temperature of 900 °C, and calcination time of 40 min. The XRD analysis revealed that a complex phase transition of the product SiO2 was also accompanied by the con-version reaction of K-feldspar/CaCl2. The SiO2 product formed at the initial stage was in the quartz phase at 900 °C and was gradually transformed into cristobalite after 30 min.

  9. CaCl2-Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29Si MAS NMR

    Qinfei Li


    Full Text Available The effect of calcium chloride (CaCl2 on tricalcium silicate (C3S hydration was investigated by scanning transmission X-ray microscopy (STXM with Near Edge X-ray Absorption Fine Structure (NEXAFS spectra and 29Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement-based hydration system. The Ca L3,2-edge NEXAFS spectra obtained by examining C3S hydration in the presence of CaCl2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C-S-H, which is the primary hydration product. O K-edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C3S. Based on the Ca L3,2-edge spectra and chemical component mapping, we concluded that CaCl2 prefers to coexist with unhydrated C3S instead of C-S-H. In Si K-edge NEXAFS analysis, CaCl2 increases the degree of silicate polymerization of C-S-H in agreement with the 29Si CP/MAS NMR results, which show that the presence of CaCl2 in hydrated C3S considerably accelerates the formation of middle groups (Q2 and branch sites (Q3 in the silicate chains of C-S-H gel at 1-day hydration.

  10. Adsorption performances and refrigeration application of adsorption working pair of CaCl2-NH3

    WANG Liwei; WANG Ruzhu; WU Jingyi; WANG Kai


    The adsorption performance of CaCl2-NH3 is studied under the condition of different expansion spaces for adsorbent, andthe relationships between adsorption performance of CaCl2-NH3 and the phenomena of swelling and agglomeration during adsorption are researched. It is found that the performance stability is related to the ratio of expansion space to the volume of adsorbent ras, and the performance attenuation is serious in the case of large ras. Severe adsorption hysteresis exists in the process of adsorption and desorption at the same evaporating and condensing temperatures, which is related to the stability constant of chemical reaction. This phenomenon cannot be explained by the theory of physical adsorption. Moderate agglomeration will be beneficial to the formation of ammoniate complex; the magnitude of expansion space will affect adsorption performance. Analysis shows that the activated energy needed in the process of adsorption for the sample with ras of 2:1 is less than that for the sample with ras of 3:1.The refrigeration performance of CaCl2-NH3 is predicted from experiments. The cooling capacity of one adsorption cycle is about 945.4 kJ/kg for the adsorbent with an ras of 2:1 at the evaporating temperature of 0℃.

  11. Electrochemical characterisation of CaCl2 deficient LiCl-KCl-CaCl2 eutectic melt and electro-deoxidation of solid UO2

    Sri Maha Vishnu, D.; Sanil, N.; Mohandas, K. S.; Nagarajan, K.


    The CaCl2 deficient ternary eutectic melt LiCl-KCl-CaCl2 (50.5: 44.2: 5.3 mol %) was electrochemically characterised by cyclic voltammetry and polarization techniques in the context of its probable use as the electrolyte in the electrochemical reduction of solid UO2 to uranium metal. Tungsten (cathodic polarization) and graphite (anodic polarization) working electrodes were used in these studies carried out in the temperature range 623 K-923 K. The cathodic limit of the melt was observed to be set by the deposition of Ca2+ ions followed by Li+ ions on the tungsten electrode and the anodic limit by oxidation of chloride ions on the graphite electrode (chlorine evolution). The difference between the onset potential of deposition of Ca2+ and Li+ was found to be 0.241 V at a scan rate of 20 mV/s at 623 K and the difference decreased with increase in temperature and vanished at 923 K. Polarization measurements with stainless steel (SS) cathode and graphite anode at 673 K showed the possibility of low-energy reactions occurring on the UO2 electrode in the melt. UO2 pellets were cathodically polarized at 3.9 V for 25 h to test the feasibility of electro-reduction to uranium in the melt. The surface of the pellets was found reduced to U metal.

  12. CaCl2含量对PA6/CaCl2复合材料结构与性能的影响%The Effect of Content of CaCl2 on the Structure and Properties of PA6/CaCl2 Composite

    鲁圣军; 李飞; 何敏; 于杰


    PA6/CaCl2 composite were prepared through melting extrusion process and structure and properties of PA6/ CaCl2 composite was studied in term of CaCl2 content. The following results were obtained: with the increasing of the CaCl2 content, the deeper the complex degree of the PA6 and CaCl2 was, the smaller the crystallinity of the PA6/CaCl2 composites was, the more the crystal degree was imperfect; the stronger the viscosity of the PA6/CaCl2 composites was, the smaller the melt index was;the stronger the flexural strength was. But with the increasing of the CaCl2 content,the tensile strength and the Izod impact strength of the PA6/CaCl2 composites had the extreme point.%采用熔融挤出的方法,制备PA6/CaCl2复合材料,研究CaCl2含量对PA6/CaCl2复合材料结构与性能的影响.结果表明:随CaCl2含量的增加,PA6/CaCl2复合材料的结晶度越小,结晶不完善程度越大;复合材料的黏度越大,熔体指数越小.PA6/CaCl2复合材料的拉伸强度,冲击强度随CaCl2含量的增加存在极值现象,弯曲强度随CaCl2含量的增加而增加.

  13. Experimental Study on Liquid-Liquid Equilibria of Alcohol-Ester-Water-CaCl2 System

    Fu Jiquan; Fu Die


    The binary liquid-liquid equilibrium (LLE) data for salt-containing systems of 1-butanol+water+CaCl2, n-butyl acetate+water+CaCl2 and ethyl acetate+acetic acid+water+CaCl2 were determined and the salt effect was analyzed. The results showed that an obvious salt effect could be identified for the systems of 1-butanol+water+CaCl2 and ethyl acetate+acetic acid+water.

  14. Cathodic behavior of molten CaCl2-CaO and CaCl2-NaCl-CaO

    Wang, Shu-Lan; Wang, Wei; Li, Shi-Chao; Cao, Shan-Hui


    The cathodic behavior of molten CaCl2, CaCl2-CaO and equimolar CaCl2-NaCl-CaO was studied by cyclic voltammograms and constant potential polarization at temperatures of 1123 to 1173 K on molybdenum and titanium electrodes. The diffusion coefficient of Ca2+ (CaO) in molten CaCl2-CaO was calculated from the linear relationship between the square root of scan rate and the peak current density. The deposition potentials and the potential temperature coefficient of CaO in molten CaCl2-0.5mol%CaO and CaCl2-NaCl-0.5mol%CaO were also obtained from their cyclic voltammograms. The result shows that CaO is more easily reduced than CaCl2. The addition of NaCl in molten CaCl2-CaO induces the underpotential electrodeposition of CaO.

  15. Nonlinear reaction coordinate analysis in the reweighted path ensemble

    Lechner, W.; Rogal, J.; Juraszek, J.; Ensing, B.; Bolhuis, P.G.


    We present a flexible nonlinear reaction coordinate analysis method for the transition path ensemble based on the likelihood maximization approach developed by Peters and Trout [J. Chem. Phys. 125, 054108 (2006)] . By parametrizing the reaction coordinate by a string of images in a collective variab

  16. The catalytic dehydrochlorination of pentachloroethane with activated carbon supported calcium chloride%活性炭负载CaCl2催化五氯乙烷脱HCl的研究

    王智春; 陈胜洲; 陈汉伦; 谢文健


    Supported catalyst calcium chloride/activated carbon(CaCl2/AC) was prepared and used in dehydrochlorination of pentachloroethane to produce perchloroethylene.Influences of reaction temperature,space velocity and CaCl2 loading amount on catalytic activity of CaCl2/AC were investigated.Stability of catalytic activity of catalyst was also studied.Results of the experiment showed that the optimal conditions were reaction temperature 240℃,space velocity 3.4h-1,CaCl2 loading amount 0.3mmol/g.Under the optimal conditions,the conversion of pentachloroethane and the yield of perchloroethylene can reach more than 99% and 95%,respectively.And the repeatability of catalytic activity of catalyst was fine.The catalysts were characterized by X-ray diffraction(XRD) and nitrogen adsorption-desorption method.The results showed that the dispersion of CaCl2 on activated carbon surface was good.The BET surface area and pore volume of CaCl2/AC catalyst gradually decreased with the CaCl2 loading amount increased.%筛选出了催化性能较好的活性炭负载氯化钙(CaCl2/AC)催化剂用于五氯乙烷脱HCl制备四氯乙烯。考察了反应温度、空速、CaCl2负载量对CaCl2/AC催化剂催化性能的影响及催化剂的稳定性。实验结果表明最佳反应条件:反应温度为240℃,空速为3.4h-1,CaCl2负载量为0.3mmol/g,在此反应条件下五氯乙烷的转化率可达99%以上,四氯乙烯的收率达95%以上,催化剂催化性能重现性良好。采用X射线衍射(XRD)、氮气吸附-脱附对催化剂进行了表征。结果表明CaCl2在活性炭表面分散良好;随着CaCl2负载量的增加,CaCl2/AC催化剂的BET比表面及孔容逐渐减小。

  17. CaCl2对月季切花衰老的影响%Effect of CaCl2 on Senescence of Cut Rose

    洪法水; 赵海泉


    CaCl2处理月季切花可以延长瓶插寿命2~4 d.CaCl2延缓切花衰老的生理效应表现为增强切花的保水能力;减少蛋白质降解;提高SOD、CAT、POD活性;降低膜脂过氧化水平,维持膜结构的相对稳定性.其中以1.5% CaCl2处理效果较好.

  18. Recent Developments in Methods for Identifying Reaction Coordinates

    Li, Wenjin


    In the study of rare events in complex systems with many degrees of freedom, a key element is to identify the reaction coordinates of a given process. Over recent years, a number of methods and protocols have been developed to extract the reaction coordinates based on limited information from molecular dynamics simulations. In this review, we provide a brief survey over a number of major methods developed in the past decade, some of which are discussed in greater detail, to provide an overview of the problems that are partially solved and challenges that still remain. A particular emphasis has been placed on methods for identifying reaction coordinates that are related to the committor.

  19. Recent developments in methods for identifying reaction coordinates.

    Li, Wenjin; Ma, Ao


    In the study of rare events in complex systems with many degrees of freedom, a key element is to identify the reaction coordinates of a given process. Over recent years, a number of methods and protocols have been developed to extract the reaction coordinates based on limited information from molecular dynamics simulations. In this review, we provide a brief survey over a number of major methods developed in the past decade, some of which are discussed in greater detail, to provide an overview of the problems that are partially solved and challenges that still remain. A particular emphasis has been placed on methods for identifying reaction coordinates that are related to the committor.

  20. A benchmark for reaction coordinates in the transition path ensemble.

    Li, Wenjin; Ma, Ao


    The molecular mechanism of a reaction is embedded in its transition path ensemble, the complete collection of reactive trajectories. Utilizing the information in the transition path ensemble alone, we developed a novel metric, which we termed the emergent potential energy, for distinguishing reaction coordinates from the bath modes. The emergent potential energy can be understood as the average energy cost for making a displacement of a coordinate in the transition path ensemble. Where displacing a bath mode invokes essentially no cost, it costs significantly to move the reaction coordinate. Based on some general assumptions of the behaviors of reaction and bath coordinates in the transition path ensemble, we proved theoretically with statistical mechanics that the emergent potential energy could serve as a benchmark of reaction coordinates and demonstrated its effectiveness by applying it to a prototypical system of biomolecular dynamics. Using the emergent potential energy as guidance, we developed a committor-free and intuition-independent method for identifying reaction coordinates in complex systems. We expect this method to be applicable to a wide range of reaction processes in complex biomolecular systems.

  1. Reactivity of bromoalkanes in reactions of coordinated molecular decay

    Pokidova, T. S.; Denisov, E. T.


    The results from experiments on reactions of the coordinated molecular decay of RBr bromoalkanes on olefin and HBr are analyzed using the model of intersecting parabolas (MIP). Kinetic parameters within the MIP are calculated from the experimental data, enabling calculation of the activation energies ( E) and rate constants ( k) of such reactions, based on the enthalphy of the reaction and the MIP algorithms. The factors affecting the E of the RBr decay reaction are established: the enthalphy of the reaction, triplet repulsion, the energy of radical R• stabilization, the presence of a π bond adjacent to the reaction center, and the dipole-dipole interaction of polar groups. The energy spectrum of the partial energies of activation is constructed for the reaction of coordinated molecular decay of RBr, and the E and k of inverse addition reactions are evaluated.

  2. Influence of NaCl-CaCl2 on Decomposing REPO4 with CaO


    The influence of NaCl-CaCl2 on thermal decomposition of REPO4 (RE: Ce, La, Nd, Th) with CaO was studied.The heat decomposing process of REPO4 was tested with TG-DTA experiments.The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture (NaCl:CaCl2=1:1).The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied.The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.

  3. The stochastic separatrix and the reaction coordinate for complex systems.

    Antoniou, Dimitri; Schwartz, Steven D


    We present a new approach to the identification of degrees of freedom which comprise a reaction coordinate in a complex system. The method begins with the generation of an ensemble of reactive trajectories. Each trajectory is analyzed for its equicommittor position or transition state; then the transition state ensemble is identified as the stochastic separatrix. Numerical analysis of the points along the separatrix for variability of coordinate location correctly identifies the components of the reaction coordinate in a test system of a double well coupled to a promoting vibration and a bath of linearly coupled oscillators.

  4. CaCl2对苹果酒酿造的影响%Effects of Adding CaCl2 Treatment on Cider Brewing

    朱传合; 张开利; 杜金华


    对以红富士苹果为原料,分别添加0.3、0.4、0.5*#g/L CaCl2的澄清苹果汁进行了研究.清汁中接种酿酒酵母Aw(Saccharomyces cerevisiae, Aw),于20℃控温发酵,陈酿、澄清后进行理化、感官分析与风味物质测定.研究显示,添加CaCl2显著地提高了果汁的澄清度、加快了果汁澄清速度.果汁处理时间低于12*#h时,CaCl2加量以0.4*#g/L为宜;处理时间在18~22*#h,CaCl2加量为0.3~0.5*#g/L.经CaCl2增加酸度(1.49~1.57*#g/L)、降低pH值(0.19~0.24)、对酵母酒精发酵、发酵过程中滴定酸和pH的变化趋势无显著影响.CaCl2处理的果汁发酵的苹果酒滴定酸度高、残糖低,总浸出物低,酒精浓度与未处理苹果酒接近;口味纯正、爽口,色泽好,果香味突出.


    王淑兰; 王伟; 王川华; 张丽君


    采用循环伏安方法研究了1173 K时CaCl2-0.5%CaO(摩尔分数)和等摩尔CaCl2-X-0.5%CaO(X=NaCl,BaCl2,LiCl)熔盐中CaO在Mo电极上的阴极行为.研究结果表明,CaCl2与CaO电离的Ca计具有不同的离子结构和还原电势,在1173 K时其还原峰电势分别为-2.15和-1.51 V.等摩尔混合熔盐CaCl2-x-0.5%CaO(x=NaCl,BaCl2)中,CaO诱发电解质产生低电位沉积,降低了混合熔盐的电化学稳定性.通过阴极扫描电流峰密度与扫描速率的关系,计算出1173 K时CaO电离的Ca2+在CaCl2-0.5%CaO,等摩尔的CaCl2-NaCl-0.5%CaO,CaCl2-BaCl2-0.5%CaO和CaCl2-LiCl-0.5%CaO熔盐中的扩散系数,分别为6.42×10-5,1.56×10-5,1.20×10-5和6.79×10-5 cm2/s.

  6. Research on the chemical adsorption precursor state of CaCl2-NH3 for adsorption refrigeration

    WANG; Liwei; WANG; Ruzhu; WU; Jingyi; WANG; Kai


    As a type of chemical adsorption working pair, the physical adsorption occurs first for CaCl2-NH3 because the effective reaction distance for van der Waals force is longer than that for chemical reaction force, and this physical adsorption state is named the precursor state of chemical adsorption. In order to get the different precursor states of CaCl2-NH3, the different distances between NH3 gas and Ca2+ are realized by the control of different phenomena of swelling and agglomeration in the process of adsorption. When the serious swelling exists while the agglomeration does not exist in the process of adsorption, experimental results show that the activated energy consumed by adsorption reaction increases for the reason of longer distance between Ca2+ and NH3, and at the same time the performance attenuation occurs in the repeated adsorption cycles. When the agglomeration occurs in the process of adsorption, the activated energy for the transition from precursor state to chemical adsorption decreases because the distance between NH3 gas and Ca2+ is shortened by the limited expansion space of adsorbent, and at the same time the performance attenuation does not occur. The adsorption refrigeration isobars are researched by the precursor state of chemical adsorption; results also show that the precursor state is a key factor for isobaric adsorption performance while the distribution of Ca2+ does not influence the permeation of NH3 gas in adsorbent.

  7. Study on Roasting Decomposition of Mixed Rare Earth Concentrate in CaO-NaCl-CaCl2


    The decomposed process of bastnaesite, monazite and mixed rare earth concentrate in CaO-CaCl-CaCl2 was studied by means of TG-DTA method. The relationship among decomposition ratio, roasting temperature, and CaO-NaCl addition was studied by the quadratic regression orthogonal analysis, and then the regression equation was obtained. Through analysis, the optimum process conditions of mixed rare earth concentrate decomposed by CaO-CaCl-CaCl2 were obtained as follows: roasting temperature: 700 ℃, CaO addition: 15%, NaCl-CaCl2 addition: 10%, roasting time: 60 min, the decomposition ratio: 91.3%.

  8. How wet should be the reaction coordinate for ligand unbinding?

    Tiwary, Pratyush


    We use a recently proposed method called Spectral Gap Optimization of Order Parameters (SGOOP) (Tiwary and Berne, Proc. Natl. Acad. Sci 2016, 113, 2839 (2016)), to determine an optimal 1-dimensional reaction coordinate (RC) for the unbinding of a bucky-ball from a pocket in explicit water. This RC is estimated as a linear combination of the multiple available order parameters that collectively can be used to distinguish the various stable states relevant for unbinding. We pay special attention to determining and quantifying the degree to which water molecules should be included in the RC. Using SGOOP with under-sampled biased simulations, we predict that water plays a distinct role in the reaction coordinate for unbinding in the case when the ligand is sterically constrained to move along an axis of symmetry. This prediction is validated through extensive calculations of the unbinding times through metadynamics, and by comparison through detailed balance with unbiased molecular dynamics estimate of the bindin...

  9. The preparation of high quality bittern by liquid CaCl2 method%液体CaCl2法制备优质卤水



    结合氯碱企业对岩盐卤水的质量要求,以石灰石及副产盐酸为原料自制液体CaCl2来脱除岩盐卤水中的SO42-,并开发了CaCl2法脱硫新工艺,大大降低了卤水处理成本,从而制备出SO42-质量浓度低于4 g/L的优质卤水,达到了离子膜制碱一次盐水对SO42-的要求.

  10. Sulfide capacities of CaO-CaF2-CaCl2 melts

    Simeonov, Simeon; Sakai, Toshihiko; Maeda, Masafumi


    The sulfide capacityC_{s^{2 - } } = ({text{pct S}}^{{text{2 - }}} )(p_{{text{O}}_{text{2}} } /p_{{text{S}}_{text{2}} } )^{1/2} ) of CaO-CaF2-CaCl2 slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO2-Ar gas mixture. The sulfide capacity increases with replacing CaCl2 by CaF2 in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF2/CaCl2 of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale.

  11. 烧结矿喷洒CaCl2溶液工业试验

    袁骏; 王红春



  12. Electrodeposition of Ca Metal in CaCl2-CaO Molten Salt

    GUO; Jun-kang; WANG; Chang-shui; CAO; Long-hao; OUYANG; Ying-gen


    To realize the continuouscalciothermic reduction in molten salts,the electrodeposition behavior of Ca metal in CaCl2-CaO molten salt was investigated by cylic voltammetry.The cyclic voltammograms at the scan rate of 100 mV/s are shown in Fig.1.As is shown,the electrodeposition potential of Ca deviated from-1.66 V to-0.97 V after CaO was added to molten CaCl2 and the decomposition of CaO

  13. Reaction mechanism and reaction coordinates from the viewpoint of energy flow.

    Li, Wenjin; Ma, Ao


    Reaction coordinates are of central importance for correct understanding of reaction dynamics in complex systems, but their counter-intuitive nature made it a daunting challenge to identify them. Starting from an energetic view of a reaction process as stochastic energy flows biased towards preferred channels, which we deemed the reaction coordinates, we developed a rigorous scheme for decomposing energy changes of a system, both potential and kinetic, into pairwise components. The pairwise energy flows between different coordinates provide a concrete statistical mechanical language for depicting reaction mechanisms. Application of this scheme to the C7eq → C7ax transition of the alanine dipeptide in vacuum revealed novel and intriguing mechanisms that eluded previous investigations of this well studied prototype system for biomolecular conformational dynamics. Using a cost function developed from the energy decomposition components by proper averaging over the transition path ensemble, we were able to identify signatures of the reaction coordinates of this system without requiring any input from human intuition.

  14. Low temperature synthesis of CaZrO3 nanoceramics from CaCl2–NaCl molten eutectic salt

    Rahman Fazli; Farhad Golestani-Fard


    CaZrO3 nanoceramics were successfully synthesized at 700 C using the molten salt method, and the effects of processing parameters, such as temperature, holding time, and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, Na2CO3, and nano-ZrO2 were used as starting materials. On heating, CaCl2–NaCl molten eutectic salt provided a liquid medium for the reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 600C and that,...

  15. Measurement of the Phase Diagram of the SiO2-CaCl2 System and Liquid Area Study of the SiO2-CaO-CaCl2 System

    Wang, Ye; Morita, Kazuki


    To optimize the process of boron removal from molten silicon, the slag refining treatment using the CaO-SiO2-CaCl2 slag system has been proven to be effective. However, the phase relations of the SiO2-CaCl2 and CaO-SiO2-CaCl2 systems have not been reported yet. Thus, in this study, the phase diagram of the SiO2-CaCl2 system was determined by using thermogravimetric differential thermal analysis (TG-DTA). Moreover, the liquid area of the CaO-SiO2-CaCl2 ternary system at 1723 K (1450 °C) was also measured by using TG-DTA and morphological observations.

  16. "JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More

    Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun


    This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

  17. Cathodic Potential Dependence of Electrochemical Reduction of SiO2 Granules in Molten CaCl2

    Yang, Xiao; Yasuda, Kouji; Nohira, Toshiyuki; Hagiwara, Rika; Homma, Takayuki


    As part of an ongoing fundamental study to develop a new process for producing solar-grade silicon, this paper examines the effects of cathodic potential on reduction kinetics, current efficiency, morphology, and purity of Si product during electrolysis of SiO2 granules in molten CaCl2 at 1123 K (850 °C). SiO2 granules were electrolyzed potentiostatically at different cathodic potentials (0.6, 0.8, 1.0, and 1.2 V vs Ca2+/Ca). The reduction kinetics was evaluated based on the growth of the reduced Si layer and the current behavior during electrolysis. The results suggest that a more negative cathodic potential is favorable for faster reduction. Current efficiencies in 60 minutes are greater than 65 pct at all the potentials examined. Si wires with sub-micron diameters are formed, and their morphologies show little dependence on the cathodic potential. The impurities in the Si product can be controlled at low level. The rate-determining step for the electrochemical reduction of SiO2 granules in molten CaCl2 changes with time. At the initial stage of electrolysis, the electron transfer is the rate-determining step. At the later stage, the diffusion of O2- ions is the rate-determining step. The major cause of the decrease in reduction rate with increasing electrolysis time is the potential drop from the current collector to the reaction front due to the increased contact resistance among the reduced Si particles.

  18. Tribological behaviors of graphite sliding against cemented carbide in CaCl2 solution

    Guo, Fei; Tian, Yu; Liu, Ying; Wang, Yuming


    The tribological behaviors of graphite sliding against cemented carbide were investigated using a standard tribological tester Plint TE92 in a ring-on-ring contact configuration in both CaCl2 solution and deionized water. An interesting phenomenon occurred: as the CaCl2 solution concentration increased, the friction coefficient firstly decreased and was lower than that in the deionized water, and then gradually increased, exceeding the friction coefficient in the deionized water. The wear rate of the ,graphite also presented the same variation trend. According to the polarization curves of cemented carbide, contact angle measurements, Raman spectrum analysis and scanning electron microscope (SEM) images analysis, the above friction and wear behaviors of graphite sliding against cemented carbide were attributed to the graphite surface wettability and the cemented carbide surface corrosion property.

  19. NaCl、NaCl—CaCl2、CaCl2盐水作基液对压井液性能影响的实验研究%Experiment and Study of the Influence of Base Fluid on Killing Fluid by Respectively Using Nacl,Nacl-CaCl2 or CaCl2 Bring as the Base Fluid




  20. Influence of CaCl(2) on the foliar biomass and quality of tobacco leaves.

    Ruiz, J M; Romero, L


    The aim of the present work was to determine the influence of different CaCl(2) dosages on foliar biomass and quality of tobacco plants (Nicotiana tabacum L. var. Tennesse 86). Plants were grown under controlled conditions and submitted to regular fertilization with macro- and micronutrients. The CaCl(2) was applied to the nutrient solution at 1.25 mM (T1), 2.5 mM (T2), and 5 mM (T3). The results indicated that, under the experimental conditions of this work, the application of 1.25 mM of CaCl(2) favored the growth and development of the leaves, this leading to improved biomass production in tobacco leaves. The increase in foliar biomass in treatment T1 could largely be a result of the stimulation of NO(3)(-) assimilation. However, this situation has negative consequences for tobacco quality, given that the T1 treatment augmented the NO(3)(-) concentration and the foliar concentration of nicotine (both effects being harmful for human consumption) and decreased the concentration of reducing sugars in leaves of tobacco plants compared with those of T2 and T3. Finally, a close and directly proportional relationship was found in our experiment between the parameters of foliar-biomass production, total N concentration, chlorophyll concentration, and decline in quality.

  1. CaCl2溶液对柿子汁涩味的影响%Research on the Effect of CaCl2 in Atringent Reminal in Persimmon Beverage

    刘晓艳; 白卫东; 赵文红; 林士莹; 吴伟媚


    以柿子为实验原料,采用CaCl2液对柿子汁进行脱涩,对CaCl2液浓度,脱涩温度,脱涩时间,及脱涩环境pH值进行探讨.通过正交试验得出:质量分数1.8%CaCl2液控制在pH 4.5和40℃的条件下脱涩15 h,脱涩率达到88.57%.

  2. Partial displacement of ZnCl2 by CaCl2 in the Zn/MnO2 battery%CaCl2部分代替锌锰电池中的ZnCl2

    熊根良; 刘煦; 杨瑞浓



  3. The reaction force: Three key points along an intrinsic reaction coordinate

    Peter Politzer; Alejandro Toro-Labbé; Soledad Gutiérrez-Oliva; Bárbara herrera; Pablo Jaque; Monica C Concha; Jane S Murray


    The concept of the reaction force is presented and discussed in detail. For typical processes with energy barriers, it has a universal form which defines three key points along an intrinsic reaction coordinate: the force minimum, zero and maximum. We suggest that the resulting four zones be interpreted as involving preparation of reactants in the first, transition to products in the second and third, and relaxation in the fourth. This general picture is supported by the distinctive patterns of the variations in relevant electronic properties. Two important points that are brought out by the reaction force are that (a) the traditional activation energy comprises two separate contributions, and (b) the transition state corresponds to a balance between the driving and the retarding forces.

  4. NaCl-CaCl2对氧化钙分解独居石的影响%Influence of NaCl-CaCl2 on Decomposing Monazite with CaO

    孙树臣; 吴志颖; 边雪; 高波; 吴文远; 涂赣峰



  5. Study on cold resistance of B.napus by sprayi ng CaCl2 at low temperature%低温胁迫下喷施CaCl2对油菜抗寒性的影响

    王春利; 杨建利


    在低温胁迫下,0.10%CaCl2可使油菜叶片的POD 酶活性及可溶性蛋白质含量稍有提高;而其他处理POD酶活性依0.18%多效唑>0.30%CaCl2 >0.50%CaCl2规律递减.各处理和喷蒸馏水相比,叶绿素含量均下降.0.10%CaCl2可增加根粗、根长、根鲜重、地上部鲜重及根冠比,有利于植株形成壮苗,增强油菜抗寒性.

  6. The effect of the concerncations of CaCl2 on the transformation efficiency of E.coli%CaCl2浓度对感受态细胞转化效率的影响



    对于E.coli 菌株用8种不同浓度的CaCl2制备感受态细胞,然后转化各浓度的感受态细胞.实验结果表明,不同浓度CaCl2溶液处理所得到的感受态细胞,其转化效率有很大的不同.随着CaCl2浓度增高,转化效率也随之提高,在80m mol/L~100m mol/L时达到峰值,进一步提高CaCl2的浓度,转化效率急剧下降.还探讨了-70℃贮存时间对转化效率的影响.

  7. Influence of CaCl2 on quality and gray mold rot in postharvest strawberry fruit%CaCl2处理对草莓采后品质及灰霉病害的影响

    赵妍; 杨超; 王若兰; 宋永令


    CaCl2 was selected to keep strawberry fresh.The influence of CaCl2 on postharvest quality and the inhibitory effect to gray mold rot during storage were studied.It was indicated that CaCl2 had the ability to maintain postharvest quality of strawberry.Especially,the strawberry fruit treated with 10% CaCl2were freshest during the whole storage.CaCl2 could also inhibit the mycelial growth and spore germination of Botrytis cinerea,and reduce the incidence of gray mold rot in strawberry fruit significantly.Furthermore,the antibacterial effect of CaCl2 was positively correlated to its concentration.The content of defense-related substances in strawberry fruit was influenced by CaCl2.On the first day of storage,strawberry fruit treated with 10% and 5% CaCl2 showed significantly higher lignin content and phenylalanine ammonia lyase (PAL)activity than the control,moreover,catalase(CAT) (6~12d)and peroxidase(POD) (9~ 12d)activities were also significantly higher than the control.Therefore,CaCl2 can induce the accumulation of disease-related substances in postharvest strawberry and thus improve the defense capability for gray mold rot in strawberry fruit.%选用CaCl2溶液处理新鲜草莓,研究其对草莓采后品质的影响及对贮期灰霉病的抑制作用.研究结果表明CaCl2处理具有较好地保持采后草莓品质的能力,尤其是经10%浓度CaCl2处理的草莓果实在贮藏期间品质最好.CaCl2处理还可以抑制灰葡萄孢的菌丝生长与孢子萌发,并显著地降低草莓果实贮藏期间灰霉病的发病率,且该抑菌效果与CaCl2使用浓度呈正相关.此外,CaCl2处理会影响草莓果实抗病相关物质的含量.经10%、5%浓度CaC12处理的草莓果实在贮藏早期(1d)其木质素含量和苯丙氨酸解氨酶(PAL)活性均显著地高于对照;而在贮藏中后期(6~12d和9~12d),其过氧化氢酶(CAT)及过氧化物酶(POD)活性也均显著地高于对照.由此可见,CaCl2处理可以诱导采

  8. XRD study on Interaction between CaCl2 and 10X Zeolite%XRD法研究CaCl2与10X分子筛的相互作用




  9. Effects of Different 6-BA Concentration Plus 3% CaCl2 on Fresh-keeping of Mustard%3%CaCl2提高6-BA对蔬菜保鲜作用的研究



    采用3%CaCl2、不同浓度的6-BA和不同浓度的6-BA+3%CaCl2对芥菜进行采后保鲜处理,结果表明,用3%CaCl2,5mg/L、10mg/L、20mg/L 6-BA+3%CaCl2处理后的芥菜,其鲜重下降率,叶绿素、蛋白质、维生素C含量的下降率,电导率的上升率均比对照降低,呼吸强度抑制比对照提高.在各种处理的组合中,6-BA的作用比3%CaCl2明显,而同一浓度6-BA中,以6-BA+3% CaCl2处理的效果比单独用6-BA处理的明显.其中以5mg/L 6-BA处理的效果最为明显.

  10. Effect of CaCl2 on Quality of Pitaya Fruits under Cold Storage%CaCl2处理对火龙果低温贮藏期品质的影响

    王彬; 郑伟; 何绪晓; 邓仁菊; 彭玉基; 周俊良


    以白肉火龙果新品种晶红龙为试验材料,研究了3种不同浓度的CaCl2溶液处理对低温贮藏期火龙果品质的影响.结果表明,CaCl2处理对火龙果呼吸作用的抑制作用不明显,但对降低火龙果的腐烂率有一定的作用,以2 % CaCl2处理效果较好,而6 % CaCl2处理可延缓果实的腐烂;2 % CaCl2处理可降低火龙果果实的水分蒸腾率;火龙果果实在整个贮藏过程中,各处理间的营养品质变化差异不显著.3种钙浓度处理中以2 % CaCl2溶液浸果效果较好.

  11. CaCl2浸种对盐胁迫玉米幼苗的生理效应%Effects of Seed Soaking with CaCl2 on Maize Seedlings under Salt Stress

    于龙凤; 安福全


    The nutrient solution culture method was employed to study the effect of CaCl2 solution soaking of maize under salt stress on seedling growth of some physiological indicators. The results show that CaCl2 solution soaking maize seedlings increased proline content,reduced the relative conductivity and water potential of maize seedlings ; under salt stress, CaCl2 solution soaking of maize seed increased chlorophyll content, promoted root activity.%采用营养液培养的方法,研究了CaCl2溶液浸种对盐胁迫下玉米幼苗生长的一些生理指标的影响。结果表明,CaCl2溶液浸种提高了玉米幼苗脯氨酸含量,降低了玉米幼苗相对电导率和水势;在盐胁迫下,CaCl2溶液浸种提高玉米幼苗叶绿素含量,增强了根系活力。

  12. CaCl2对非洲菊切花保鲜效果的研究

    夏晶晖; 梅巧灵


    以浓度4 g/L、6 g/L、8 g/L、10g/L4个的CaCl2作为保鲜液,通过外部形态观察和生理指标测定,研究CaCl2对非洲菊切花瓶插保鲜效果.结果表明:CaCl2对延缓切花菊的衰老有一定作用,可比对照延长4 d瓶插寿命,增加花枝鲜重,减缓花瓣组织中蛋白质和糖含量的分解速变.各处理中以含8 g/L的CaCl2配方效果最好,可使切花非洲菊的瓶插寿命.

  13. CaCl2-CaO熔盐中金属钙的电沉积行为研究




  14. Acoustic attenuation due to transformation twins in CaCl2: Analogue behaviour for stishovite

    Zhang, Zhiying; Schranz, Wilfried; Carpenter, Michael A.


    CaCl2 undergoes a tetragonal (P42/mnm) to orthorhombic (Pnnm) transition as a function of temperature which is essentially the same as occurs in stishovite at high pressures. It can therefore be used as a convenient analogue material for experimental studies. In order to investigate variations in elastic properties associated with the transition and possible anelastic loss behaviour related to the mobility of ferroelastic twin walls in the orthorhombic phase, the transition in polycrystalline CaCl2 has been examined using resonant ultrasound spectroscopy (RUS) at high frequencies (0.1-1.5 MHz) in the temperature interval 7-626 K, and dynamic mechanical analysis (DMA) at low frequencies (0.1-50 Hz) in the temperature interval 378-771 K. RUS data show steep softening of the shear modulus as the transition temperature is approached from above and substantial acoustic dissipation in the stability field of the orthorhombic structure. DMA data show softening of the storage modulus, which continues through to a minimum ˜20 K below the transition point and is followed by stiffening with further lowering of temperature. There is no obvious acoustic dissipation associated with the transition, as measured by tan δ, however. The elastic softening and stiffening matches the pattern expected for a pseudoproper ferroelastic transition as predicted elsewhere. Acoustic loss behaviour at high frequencies fits with the pattern of behaviour expected for a twin wall loss mechanism but with relaxation times in the vicinity of ˜10-6 s. With such short relaxation times, the shear modulus of CaCl2 at frequencies corresponding to seismic frequencies would include relaxations of the twin walls and is therefore likely to be significantly lower than the intrinsic shear modulus. If these characteristics apply also to twin wall mobility in stishovite, the seismic signature of the orthorhombic phase should be an unusually soft shear modulus but with no increase in attenuation.

  15. Pengaruh Konsentrasi CaCl2 Dan Alginat Terhadap Karakteristik Analog Bulir Jeruk Dari Alginat

    Rosmawaty Peranginangin


    Full Text Available Alginat memiliki sifat dapat membentuk gel dengan adanya ion Ca2+, yang dapat dimanfaatkan sebagai bahan dasar pembuatan bulir jeruk analog. Tujuan penelitian ini adalah untuk mendapatkan konsentrasi alginat dan CaCl2 yang optimum dalam pembuatan bulir jeruk analog  dengan menggunakan response surface methodology (RSM dan mempelajari karakteristik bulir jeruk analog yang dihasilkan. RSM dengan central composite design (CCD pada software Design Expert 7 (DX 7 digunakan dengan variasi konsentrasi alginat dan konsentrasi CaCl2 sebagai variabel. Parameter yang diamati pada analog bulir jeruk meliputi kekuatan gel, viskositas, sineresis, dan pH. Selain itu juga diamati kadar air, kadar abu, kadar serat, dan uji sensoris (hedonik skala 5. Analog bulir jeruk disimpan dalam larutan sari jeruk  selama 1 bulan dengan pengamatan berat dan warna periode per minggu. Optimasi dilakukan dengan menggunakan program DX 7 (RSM dan 5 kali ulangan pada bulir jeruk yang dibuat dari alginat 0,8% dan CaCl2 0,5%.  Analog bulir jeruk yang dihasilkan memiliki kekuatan gel 130,29 g/cm2; viskositas larutan 118,6 cPs; sineresis 43,47% dan pH 3,99; sedangkan kadar air 94,05%; kadar abu 0,35%; kadar serat 2,46%. Hasil uji hedonik skala 5 pada analog bulir jeruk  memiliki nilai yaitu mendekati suka untuk tekstur (3,73, suka untuk kenampakan (4 dan antara agak suka hingga suka untuk rasa (3,53.

  16. Thermodynamic characteristics of the heparin-leucine-CaCl2 system in a diluted physiological solution

    Nikolaeva, L. S.; Belov, G. V.; Rulev, Yu. A.; Semenov, A. N.


    Chemical equilibria in aqueous solutions of high-molecular weight heparin (Na4hep) and leucine (HLeu) are calculated through the mathematical modeling of chemical equilibria based on representative experimental pH titration data. In addition, chemical equilibria in the CaCl2-Na4hep-HLeu-H2O-NaCl system in the presence of 0.154M NaCl background electrolyte at a temperature of 37°C in the range of 2.30 ≤ pH ≤ 10.50 and initial concentrations of basic components n × 10-3 M ( n ≤ 4).

  17. Electrochemical Behavior of Dissolved Fe2O3 in Molten CaCl2-KF

    WANG Shu-lan; Geir Martin Haarberg; Eirin Kvalheim


    The elctrochemical behavior of dissolved Fe2O3 in 82.5CaCl2-17.5KF(mole percent,%)was studied using cyclic voltammetry,chronoamperometry,and galvanostatic electrolysis at 827℃,and the deposits were characterized by XRD and SEM.Pure iron was deposited on a rotating cylinder(210 r/min)with a cell voltage less than-1.0 V.Deposition rate was controlled by diffusion on a molybdenum electrode.The diffusion coefficient of iron species Fe(Ⅲ)in the melt at 827℃was found to be 9.7×105cm2/s.

  18. Multisite ion model in concentrated solutions of divalent cations (MgCl2 and CaCl2): osmotic pressure calculations.

    Saxena, Akansha; García, Angel E


    Accurate force field parameters for ions are essential for meaningful simulation studies of proteins and nucleic acids. Currently accepted models of ions, especially for divalent ions, do not necessarily reproduce the right physiological behavior of Ca(2+) and Mg(2+) ions. Saxena and Sept (J. Chem. Theor. Comput. 2013, 9, 3538-3542) described a model, called the multisite-ion model, where instead of treating the ions as an isolated sphere, the charge was split into multiple sites with partial charge. This model provided accurate inner shell coordination of the ion with biomolecules and predicted better free energies for proteins and nucleic acids. Here, we expand and refine the multisite model to describe the behavior of divalent ions in concentrated MgCl2 and CaCl2 electrolyte solutions, eliminating the unusual ion-ion pairing and clustering of ions which occurred in the original model. We calibrate and improve the parameters of the multisite model by matching the osmotic pressure of concentrated solutions of MgCl2 to the experimental values and then use these parameters to test the behavior of CaCl2 solutions. We find that the concentrated solutions of both divalent ions exhibit the experimentally observed behavior with correct osmotic pressure, the presence of solvent separated ion pairs instead of direct ion pairs, and no aggregation of ions. The improved multisite model for (Mg(2+) and Ca(2+)) can be used in classical simulations of biomolecules at physiologically relevant salt concentrations.

  19. A.c. susceptibility study of CaCl2 doped copper–zinc ferrite system

    A Y Lipare; P N Vasambekar; A S Vaingankar


    Polycrystalline soft ferrites, Zn$_x$ Cu$_{1–x}$ Fe2O4 ( = 0.30, 0.50, 0.70, 0.80 and 0.90), doped with controlled amount of calcium chloride (CaCl2) were prepared by standard ceramic route and studied for a.c. susceptibility. X-ray diffraction studies of the compositions reveal formation of single-phase cubic spinel. The values of lattice constant increase as doping percentage of CaCl2 increased from 0.01% to 0.05% and afterwards decrease slightly. The presence of chlorine ions is confirmed by absorption peak in far IR spectra near 650 cm-1 for all the samples. The variation of a.c. susceptibility with temperature shows the existence of single domain structure for = 0.3 and exhibits transition from single domain to multidomain structure with increased Ca2+ contents from 0.01 to 0.1%. The composition, = 0.5, shows multidomain structure independent of Ca2+ content. The samples for = 0.70, 0.80 and 0.90 show paramagnetic behaviour at and above room temperature.

  20. The Effect of CaCl_2 Fresh-keeping Liquid on Cutrose in Vase%CaCl2溶液对月季切花瓶插的影响



    In the paper,the base of cut Rosa was steeped in traditional Preservation solution added different levels of CaCl2 solution,and observed outword norphology and determined physiological index,the result show:The CaCl2 solution could increase the ability th%本研究在传统切花保鲜液中加入不同浓度的CaCl2溶液,对月季切花进行了瓶插试验。通过外部形态观察和生理指标测定,结果表明:用CaCl2溶液瓶插月季切花可以增强花枝的吸水能力,增加花枝的鲜重,增加切花的开放程度,延长瓶插寿命,其中以3%蔗糖+200 mg·L^-18-羟基喹啉+200 mg·L^-1柠檬酸+0.5%CaCl2溶液保鲜效果最好。

  1. CaCl2对月季切花瓶插效果的影响%Study on Preservation Effects of CaCl2 on Cut Rose

    齐颖; 刘爱媛; 冯淑杰; 张荣


    [目的]探讨CaCl2在月季切花瓶插过程中的保鲜效果.[方法]以月季"红衣主教"为试验材料,研究在月季瓶插过程中,3种不同浓度5、10和15 g/L的CaCl2对月季切花的外观品质,瓶插寿命,鲜重变化率及水分平衡值的影响.[结果]结果表明,3种不同浓度的CaCl2处理,均可以不同程度地促进月季切花吸水,增大切花鲜重,维持水分平衡,延缓切花变色和弯头时间,延长瓶插寿命.其中5 g/L CaCl2处理效果最好,瓶插寿命比对照延长约3 d.[结论]5 g/L CaCl2+蒸馏水+200 mg/L 8-羟基喹啉是该试验最好的处理方法.

  2. Influence of CaCl2 Treatment on Lipid Peroxidation in Eggplant Seedlings%CaCl2处理对茄子幼苗膜脂过氧化的影响

    王凤华; 王贵学; 赖钟雄; 林德清


    以营养液栽培的茄子幼苗为试材,研究了低温(4℃)胁迫下CaCl2处理对质膜透性、MDA含量、POD活性和POD同工酶的影响.结果表明:CaCl2处理能降低质膜透性,减少MAD含量.在48h前CaCl2处理能显著提高POD酶活性,48h后可以阻止其下降,不同CaCl2处理水平之间POD活性差异达显著水平,其变化趋势为0mmol/L<5mmol/L<10mmol/L<15mmol/L<20mmol/L, 同时CaCl2处理还诱导产生POD同工酶.

  3. Reaction coordinates, one-dimensional Smoluchowski equations, and a test for dynamical self-consistency.

    Peters, Baron; Bolhuis, Peter G; Mullen, Ryan G; Shea, Joan-Emma


    We propose a method for identifying accurate reaction coordinates among a set of trial coordinates. The method applies to special cases where motion along the reaction coordinate follows a one-dimensional Smoluchowski equation. In these cases the reaction coordinate can predict its own short-time dynamical evolution, i.e., the dynamics projected from multiple dimensions onto the reaction coordinate depend only on the reaction coordinate itself. To test whether this property holds, we project an ensemble of short trajectory swarms onto trial coordinates and compare projections of individual swarms to projections of the ensemble of swarms. The comparison, quantified by the Kullback-Leibler divergence, is numerically performed for each isosurface of each trial coordinate. The ensemble of short dynamical trajectories is generated only once by sampling along an initial order parameter. The initial order parameter should separate the reactants and products with a free energy barrier, and distributions on isosurfaces of the initial parameter should be unimodal. The method is illustrated for three model free energy landscapes with anisotropic diffusion. Where exact coordinates can be obtained from Kramers-Langer-Berezhkovskii-Szabo theory, results from the new method agree with the exact results. We also examine characteristics of systems where the proposed method fails. We show how dynamical self-consistency is related (through the Chapman-Kolmogorov equation) to the earlier isocommittor criterion, which is based on longer paths.

  4. Fep1d: a script for the analysis of reaction coordinates.

    Banushkina, Polina V; Krivov, Sergei V


    The dynamics of complex systems with many degrees of freedom can be analyzed by projecting it onto one or few coordinates (collective variables). The dynamics is often described then as diffusion on a free energy landscape associated with the coordinates. Fep1d is a script for the analysis of such one-dimensional coordinates. The script allows one to construct conventional and cut-based free energy profiles, to assess the optimality of a reaction coordinate, to inspect whether the dynamics projected on the coordinate is diffusive, to transform (rescale) the reaction coordinate to more convenient ones, and to compute such quantities as the mean first passage time, the transition path times, the coordinate dependent diffusion coefficient, and so forth. Here, we describe the implemented functionality together with the underlying theoretical framework.

  5. Steady-state equation of water vapor sorption for CaCl2-based chemical sorbents and its application

    Zhang, Haiquan; Yuan, Yanping; Sun, Qingrong; Cao, Xiaoling; Sun, Liangliang


    Green CaCl2-based chemical sorbent has been widely used in sorption refrigeration, air purification and air desiccation. Methods to improve the sorption rate have been extensively investigated, but the corresponding theoretical formulations have not been reported. In this paper, a sorption system of solid-liquid coexistence is established based on the hypothesis of steady-state sorption. The combination of theoretical analysis and experimental results indicates that the system can be described by steady-state sorption process. The steady-state sorption equation, μ = (η - γT) , was obtained in consideration of humidity, temperature and the surface area. Based on engineering applications and this equation, two methods including an increase of specific surface area and adjustment of the critical relative humidity (γ) for chemical sorbents, have been proposed to increase the sorption rate. The results indicate that the CaCl2/CNTs composite with a large specific surface area can be obtained by coating CaCl2 powder on the surface of carbon nanotubes (CNTs). The composite reached sorption equilibrium within only 4 h, and the sorption capacity was improved by 75% compared with pure CaCl2 powder. Furthermore, the addition of NaCl powder to saturated CaCl2 solution could significantly lower the solution’s γ. The sorption rate was improved by 30% under the same environment.

  6. Steady-state equation of water vapor sorption for CaCl2-based chemical sorbents and its application

    Zhang, Haiquan; Yuan, Yanping; Sun, Qingrong; Cao, Xiaoling; Sun, Liangliang


    Green CaCl2-based chemical sorbent has been widely used in sorption refrigeration, air purification and air desiccation. Methods to improve the sorption rate have been extensively investigated, but the corresponding theoretical formulations have not been reported. In this paper, a sorption system of solid-liquid coexistence is established based on the hypothesis of steady-state sorption. The combination of theoretical analysis and experimental results indicates that the system can be described by steady-state sorption process. The steady-state sorption equation, μ = (η − γT) , was obtained in consideration of humidity, temperature and the surface area. Based on engineering applications and this equation, two methods including an increase of specific surface area and adjustment of the critical relative humidity (γ) for chemical sorbents, have been proposed to increase the sorption rate. The results indicate that the CaCl2/CNTs composite with a large specific surface area can be obtained by coating CaCl2 powder on the surface of carbon nanotubes (CNTs). The composite reached sorption equilibrium within only 4 h, and the sorption capacity was improved by 75% compared with pure CaCl2 powder. Furthermore, the addition of NaCl powder to saturated CaCl2 solution could significantly lower the solution’s γ. The sorption rate was improved by 30% under the same environment. PMID:27682811


    胡涛; 秦延华; 张红丽; 陈伟; 左鸿涛



  8. The Effects of CaCl2 and Glycerin on Cyamopsis Tetragonoloba (1) Taubert Seed Vigor and Cold-Resistance%CaCl2和甘油对瓜尔豆种子活力的影响

    郑群; 吕国华; 李辉; 樊新民


    用不同浓度的CaCl2和甘油溶液在15℃条件下处理瓜尔豆种子24 h,放人(15±1.5)℃的发芽箱中发芽.结果表明:0.5%CaCl2溶液极显著提高了瓜尔豆种子的发芽率、发芽势、发芽指数和活力指数;1%的甘油和1%CaCl2也有提高种子活力的趋势,但效果不显著.

  9. CaCl2对月季切花保鲜效应的研究%Study of CaCl2 on Fresh-keeping Effect of Cut Rose

    杨晓盆; 王跃进



  10. Low temperature synthesis of CaZrO3 nanoceramics from CaCl2–NaCl molten eutectic salt

    Rahman Fazli


    Full Text Available CaZrO3 nanoceramics were successfully synthesized at 700 C using the molten salt method, and the effects of processing parameters, such as temperature, holding time, and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, Na2CO3, and nano-ZrO2 were used as starting materials. On heating, CaCl2–NaCl molten eutectic salt provided a liquid medium for the reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 600C and that, after the temperature was increased to 1,000C, the amounts of CaZrO3 in the resultant powders increased with a concomitant decrease in CaCO3and ZrO2 contents. After washing with hot distilled water, the samples heated for 3 h at 700C were single-phase CaZrO3 with 90–95 nm particle size. Furthermore, the synthesized CaZrO3 particles retained the size and morphology of the ZrO2 powders which indicated that a template mechanism dominated the formation of CaZrO3 by molten-salt method.

  11. Effects of Inclusions in HSLA Carbon Steel on Pitting Corrosion in CaCl2

    M. Ziomek-Moroz; S. Bullard; K. Rozman; J.J. Kruzic


    Susceptibility of high strength low alloy steel to localized corrosion was studied in 6.7 M CaCl{sub 2} for oil and natural gas drilling applications. Results of the immersion and electrochemical experiments showed that the steel is susceptible to pitting corrosion. Optical microscopy investigations of the polished samples revealed that 10% of the surface area was occupied by defects in the form of pits. The energy dispersive X-ray (EDX) and wavelength dispersive X-ray (WDX) chemical analyses revealed higher concentrations of Mn and S compared to the metal matrix in defected areas. These areas served as the sites for development of corrosion pits during both immersion and electrochemical experiments. The fatigue results of the corroded samples indicate that if the pit was the most significant defect, the fatigue crack initiated and propagated at this site.

  12. Ellagic acid improved arrhythmias induced by CaCL2 in the rat stress model

    Mahin Dianat


    Full Text Available Objective: In ventricular arrhythmias, due to their free radical scavenging action, antioxidant agents are usually used in the treatment of cardiovascular disease. Since stress is considered as risk factor for increased mortality by causing malignant arrhythmias, the study was designed to evaluate the cardioprotective effects of ellagic acid (EA on CaCl2-induced arrhythmias in rat stress model. Materials and Methods: Male Sprague-Dawley rats (200-250 g were divided into four groups: Group I: Control rats (2 ml of saline by gavage, Group II: Rats treated with EA (15 mg/kg, gavage, Group III: stress group, Group IV: received EA plus stress. Stress was applied in a restrainer box (6 hour/day, 21 days. After induction of anesthesia, lead II electrocardiogram was recorded for calculating heart rate and QRS complex. The arrhythmia was produced by injection of CaCl2 solution (140 mg/kg, iv and incidences of Ventricular fibrillation, Ventricular premature beats and Ventricular tachycardia were recorded. Results were analyzed by using one-way ANOVA and Fisher`s exact test. pResults: The results showed a positive inotropic effect and negative chronotropic effect for the EA group in comparison with the control group. Incidence rates (% of premature beats, ventricular fibrillation and ventricular tachycardia in stress group and all the arrhythmia parameters decreased in groups which received EA. Conclusions:  By decreasing the incidence rates of premature beats, fibrillation and ventricular tachycardia in groups which received EA, ellagic acid probably acted as an anti-arrhythmic agent which showed to have aprotective functionin heart.

  13. Distribution threshold values of CaCl2 onto the 10X-zeolite and macro-pore silica gel

    TANG YouCheng; LI Bin; YANG JingChang; CHU Wei; LUO ShiZhong


    The calcium chloride used for adsorption separation of ammonia is promising for its large adsorptive capacity and lower desorption temperature, but difficult to develop because of the liable expansion, lump and chip in the adsorption/desorption process. Composite adsorbents made by monolayer dis-persion of calcium chloride onto carriers with high surface areas exhibit better adsorptive capacity and stability. Several models were developed to confirm the maximum monolayer dispersion capacity of calcium chloride onto the carriers (the distribution threshold value), and the closely packed monolayer dispersion model was considered the most suitable for this study. The distribution threshold values given by this model were 0.60 g CaCl2/(g 10X-zeolite) and 0.38 g CaCl2/(g SiO2). When the divalent salt was dispersed onto the carriers, however, anions were separated into two types, causing that the en-tropy of the system tended to increase and the system was not stable. To minimize the entropy, a new model was put forward as the modified closely packed monolayer dispersion model. Based on this model, the distribution threshold values are 0.52 g CaCl2/(g 10X-zeolite) and 0.33 g CaCl2/(g SiO2), re-spectively. The distribution threshold values were also gained experimentally by XRD quantitative phase analysis: 0.61 g CaCl2/(g 10X-zeollte) and 0.31 g CaCl2/(g SiO2). Comparison between experi-mental values of distribution threshold with theoretical ones based on two different model showed that the closely packed monolayer dispersion model fits the monolayer dispersion of calcium chloride onto micro-pore carrier -10X-zeolite, and the modified closely packed monolayer dispersion model is more suitable for the bigger aperture carrier -macro-pore silica gel.

  14. 典型土壤中有效态镉CaCl2提取条件优化研究%Optimization of CaCl2Extraction of Available Cadmium in Typical Soils

    颜世红; 吴春发; 胡友彪; 李振炫; 卢青松; 陈树; 杨泉军


    In order to study the optimal conditions for extracting available cadmium from different types of soil with CaCl2, different concentrations of CaCl2 were used to extract available cadmium from sierozem and paddy soil with different extraction times. The results showed that: the extracted cadmium by CaCl2 was water-soluble and exchangeable cadmium, and the extracted contents increased with the time prolonged. The extracted cadmium by 0.01 mol/L CaCl2 from paddy soil reached equilibrium after 3 h and accounted for 4.68%-54.90% of the sum of water-soluble cadmium and exchangeable cadmium; the extracted cadmium by 0.01 mol/L CaCl2 from sierozem reached equilibrium after 3 h and accounted for 3.60%-3.89% of the sum of water-soluble cadmium and exchangeable cadmium; the extracted cadmium by 0.1 mol/L CaCl2 from paddy soil reached equilibrium after three hours and accounted for 83.28%-90.32% of the sum of water-soluble cadmium and exchangeable cadmium; the extracted cadmium by 0.01 mol/L CaCl2 from paddy soil reached equilibrium after 3 h and accounted for 44.21%-45.26% of the sum of water-soluble cadmium and exchangeable cadmium. It indicated that 0.1 mol/L CaCl2 was more suitable than 0.01 mol/L CaCl2 in available cadmium extracting for paddy soil and sierozem , and their equilibrium time was 12 h and 3 h, respectively.%为了研究CaCl2提取不同类型土壤中有效态镉的优化条件,以中国南方酸性水稻土和西北中偏碱性灰钙土为研究对象,探讨不同浓度CaCl2提取剂和不同提取时间对2种土壤中镉提取量的影响.结果表明,CaCl2提取的镉主要为土壤中的水溶态镉与部分交换态镉;0.01 mol/L CaCl2浸提下,酸性水稻土在3h达到平衡,提取量占土壤中水溶态与交换态镉含量之和的4.68%~54.90%,灰钙土仅需1h就达到平衡,但提取量占土壤中水溶态与交换态镉含量之和的3.60%~3.89%;0.1 mol/L CaCl2浸提下,水稻土需12h才达到平衡,提取量占土壤中水

  15. Near-infrared spectroscopic investigation of water in supercritical CO2 and the effect of CaCl2

    Wang, Zheming; Felmy, Andrew R.; Thompson, Christopher J.; Loring, John S.; Joly, Alan G.; Rosso, Kevin M.; Schaef, Herbert T.; Dixon, David A.


    Near-infrared (NIR) spectroscopy was applied to investigate the dissolution and chemical interaction of water dissolved into supercritical carbon dioxide (scCO2) and the influence of CaCl2 in the co-existing aqueous phase at fo empe e : 40 50 75 nd 100 C at 90 atm. Consistent with the trend of the vapor pressure of water, the solubility of pure water in scCO2 inc e ed f om 40 °C (0.32 mole%) o 100 °C (1.61 mole%). The presence of CaCl2 negatively affects the solubility of water in scCO2: at a given temperature and pressure the solubility of water decreased as the concentration of CaCl2 in the aqueous phase increased, following the trend of the activity of water. A 40 °C, the water concentration in scCO2 in contact with saturated CaCl2 aqueous solution was only 0.16 mole%, a drop of more than 50% as compared to pure water while that a 100 °C was 1.12 mole%, a drop of over 30% as compared to pure water, under otherwise the same conditions. Analysis of the spectral profiles suggested that water dissolved into scCO2 exists in the monomeric form under the evaluated temperature and pressure conditions, for both neat water and CaCl2 solutions. However, its rotational degrees of freedom decrease at lower temperatures due to higher fluid densities, leading to formation of weak H2O:CO2 Lewis acid-base complexes. Similarly, the nearly invariant spectral profiles of dissolved water in the presence and absence of saturated CaCl2 under the same experimental conditions was taken as evidence that CaCl2 dissolution in scCO2 was limited as the dissolved Ca2+/CaCl2 would likely be highly hydrated and would alter the overall spectra of waters in the scCO2 phase.

  16. [Determination of enthalpy change of coordinating color reaction by UV-Vis absorption spectrum method].

    Yang, D; An, L; Chen, L


    In this paper, a simple experimental method for the determination of enthalpy change of coordinating color reaction has been proposed and a relation formula between absorption and temperature has been deduced. Using coordinating color reaction of cobalt(II) thiocyanate in Tween-80 medium, the linear relation of this formula has been validated: r = 0.9957 and delta H = -44.7 kJ.mol-1, which is accordant with the result obtained from Van't Hoff equation.

  17. Definition and determination of the triplet-triplet energy transfer reaction coordinate

    Zapata, Felipe; Marazzi, Marco; Castaño, Obis; Frutos, Luis Manuel, E-mail: [Departamento de Química Física, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Acuña, A. Ulises [Instituto de Química Física “Rocasolano”, C.S.I.C., Serrano 119, 28006 Madrid (Spain)


    A definition of the triplet-triplet energy transfer reaction coordinate within the very weak electronic coupling limit is proposed, and a novel theoretical formalism is developed for its quantitative determination in terms of internal coordinates The present formalism permits (i) the separation of donor and acceptor contributions to the reaction coordinate, (ii) the identification of the intrinsic role of donor and acceptor in the triplet energy transfer process, and (iii) the quantification of the effect of every internal coordinate on the transfer process. This formalism is general and can be applied to classical as well as to nonvertical triplet energy transfer processes. The utility of the novel formalism is demonstrated here by its application to the paradigm of nonvertical triplet-triplet energy transfer involving cis-stilbene as acceptor molecule. In this way the effect of each internal molecular coordinate in promoting the transfer rate, from triplet donors in the low and high-energy limit, could be analyzed in detail.

  18. The potentials of multi-nutrient soil extraction with 0.01 M CaCl2 in nutrient management

    Erp, van P.J.


    Key words: 0.01 M CaCl 2 , soil testing, nutrient management, decision-making, multi-nutrient

    Aim of this thesis is to improve the understanding of nutrient dynamics in soil and thereby to improve

  19. The potentials of multi-nutrient soil extraction with 0.01 M CaCl2 in nutrient management

    Erp, van P.J.


     Key words: 0.01 M CaCl 2 , soil testing, nutrient management, decision-making, multi-nutrientAim of this thesis is to improve the understanding of nutrient dynamics in soil and thereby to improve decision-making in nutrient management. There is a need for a more mechanistic

  20. Electronic and Elastic Properties of CrO2 in the Orthorhombic CaCl2-TYPE Structure

    Wu, H. Y.; Chen, Y. H.; Deng, C. R.; Su, X. F.


    The structure, electronic and elastic properties of CrO2 in the high pressure orthorhombic CaCl2 (Pnnm) phase are investigated by first-principles calculations based on density functional theory (DFT). Our calculated crystal parameters are in good agreement with the available experimental data. The electronic band structure, density of state (DOS) and projected density of state (PDOS) at 14 GPa are studied within local spin density approximation (LSDA) and generalized gradient approximation (GGA) in details. The CaCl2 phase of CrO2 still has the half metal character, which is in accordance with previous theoretical predictions. The elastic constants, bulk modulus, shear modulus, Young's modulus and Poisson ratio under pressures are successfully obtained for the orthorhombic CaCl2 phase of CrO2. This structure is mechanically stable at our applied range of pressures. The calculated elastic anisotropic factors show that the CaCl2 phase of CrO2 is provided with high elastic anisotropy and the elastic anisotropy decreases with increasing pressures. The propagation speed of transverse, longitudinal elastic wave together with associated Debye temperatures are also estimated.

  1. Effect of Chlorine on the Viscosities and Structures of CaO-SiO2-CaCl2 Slags

    Wang, Cui; Zhang, Jianliang; Liu, Zhengjian; Jiao, Kexin; Wang, Guangwei; Yang, Junqiang; Chou, Kuochih


    The viscosities of CaO-SiO2-CaCl2 (CaO/SiO2 = 1.12) slags were measured to elucidate the effect of chlorine with CaCl2 content from 0 to 15 mass pct on the slags at high temperatures, and the Raman spectra of the glassy slags were detected to account for the role of chlorine in modifying the structures of the slags. The viscosity was found to increase with decreasing temperature and to decrease with increasing chlorine content at a given temperature. The critical temperature (T CR) decreased from about 1675 K to 1621 K (1402 °C to 1348 °C) with increasing CaCl2 content from 5 to 15 mass pct, and the activation energy decreased from 226 to 152 kJ/mol with CaCl2 content increasing from 0 to 15 mass pct. Meanwhile, the Raman spectra gradually shifted to lower wavenumber, the fractions of Q 0 and Q 2 units increased and the Q 1 and Q 3 units decreased continuously, and the Q 3/Q 2 ratio generally decreased with increasing the chlorine content in the investigated slags; all of these results above demonstrated the role of network modifier of the chlorine in decreasing the degree of polymerization in the silicon-oxygen tetrahedra.

  2. CaCl(2) as a bifunctional reusable catalyst: diversity-oriented synthesis of 4H-pyran library under ultrasonic irradiation.

    Safaei, Hamid Reza; Shekouhy, Mohsen; Shirinfeshan, Athar; Rahmanpur, Sudabeh


    CaCl(2) is applied as an efficient reusable and eco-friendly bifunctional catalyst for the one-pot three-component synthesis of 4H-pyrans under ultrasonic irradiation. A broad range of substrates including the aromatic and heteroaromatic aldehydes, indoline-2,3-dione (isatin) derivatives, acenaphthylene-1,2-dione (acenaphthenequinone) and 2, 2-dihydroxy-2H-indene-1,3-dione (ninhydrin) were condensed with carbonyl compounds possessing a reactive α-methylene group and alkylmalonates. All reactions are completed in short times, and the products are obtained in good to excellent yields. The catalyst could be recycled and reused several times without any loss of efficiency.

  3. Local Effects in the X-ray Absorption Spectrum of CaCl2, MgCl2, and NaCl Solutions

    Kulik, H J; Correa Tedesco, A A; Schwegler, E; Prendergast, D; Galli, G


    Both first principles molecular dynamics and theoretical X-ray absorption spectroscopy have been used to investigate the aqueous solvation of cations in 0.5 M MgCl{sub 2}, CaCl{sub 2}, and NaCl solutions. We focus here on the species-specific effects that Mg{sup 2+}, Ca{sup 2+}, and Na{sup +}, have on the X-ray absorption spectrum of the respective solutions. For the divalent cations, we find that the hydrogen bonding characteristics of the more rigid magnesium first shell water molecules differ from those in the more flexible solvation shell surrounding calcium. In particular, the first solvation shell water molecules of calcium are accessible to forming acceptor hydrogen bonds, and this results in an enhancement of a post-edge peak near 540 eV. The absence of acceptor hydrogen bonds for magnesium first shell water molecules provides an explanation for the experimental and theoretical observation of a lack of enhancement at the post-main-edge peak. For the sodium monovalent cation we find that the broad tilt angle distribution results in a broadening of post-edge features, despite populations in donor-and-acceptor configurations consistent with calcium. We also present the re-averaged spectra of the MgCl{sub 2}, CaCl{sub 2}, and NaCl solutions and show that trends apparent with increasing concentration (0.5 M, 2.0 M, 4.0 M) are consistent with experiment. Finally, we examine more closely both the effect that cation coordination number has on the hydrogen bonding network and the relative perturbation strength of the cations on lone pair oxygen orbitals.

  4. Penggunaan Hot Water Treatment dan CaCl2 untuk Mencegah Kerusakan Fisiologis Buah Belimbing (Averrhoa carambola L.

    Siti Trinurasih


    Full Text Available Demand and productivity of starfruit have been increased every year. With that potency, starfruit could determined as national fruit commodityto be exported. One of the obstacle that encountered by fruit export from Indonesia was the high attack of pest or fruit fly which caused many fruit do not qualify in the quarantine process. Moreover, the problem of postharvest handling should be more focused because the starfruit was perishable commodity. In this research, postharvest handling was combination of hot water treatment and soaking in CaCl2 solution. This research used starfruit variety of Dewi with ripeness index of level 4. Samples treated with hot water treatment (HWT with three levels (35oC for 60’; 45oC for 40’ and 55oC for 15’. After HWT, samples treated with soaking in CaCl2 solution at three level treatments (60’; 40’; dan 20’. The results showed that HWT was very significantly affected on overall starfruit quality during storage, whereas treatment of soaking in CaCl2 solution wasn’t significantly affected on starfruit quality. Meanwhile, combination of HWT and CaCl2 were significantly affected to respiration rate, weight shrinkage, brightness level, yellow-blue pulp level, and panelists acceptance toward flavor and aroma. Treatment of HWT 55ºC for 15 minutes, softening of fruit pulp cannot be avoided because of the heat injury. Combination of HWT 45ºC for 40 minutes and 4% CaCl2 for 60 minutes can maintain quality till 24th day panelist acceptance test.

  5. Equations for calculation of NaCl/( NaCl + CaCl2 ) ratios and salinities from hydrohalite-melting and ice-melting temperatures in the H2O-NaCl-CaCl2 system%利用H2O-NaCl-CaCl2体系水盐化合物和冰的融化温度计算NaCl/(NaCl+CaCl2)比值和盐度的方程

    Guoxiang Chi; Pei Ni


    The composition of fluid inclusions in the H2O-NaCl-CaCl2 system has been generally graphically estimated using the melting temperatures of hydrohalite ( Tm-HH ) and ice ( Tm-ice ). Here we present two equations that can be used to calculate the relative proportion of NaCl ( i. e. , NaCt/[ NaCl + CaCl2 ], or XNaCl) and the total salinity ( i. e. , NaCl + CaCl2, wt% ) for fluid inclusions with ice as the last melting phase. XNaCl can be calculated from Tm-HH using the following equation:y= ( a + bx)-1/c where y is XNaCl, x is Tm-HH, a =0. 33124402, b = -0.031518028, and c =0. 22932736. In the cases where only Tm-ice is measured and Tm-HH is not known, Tm-ice can be used as the maximum possible Tm-HH to calculate the maximum value of XNaCl using the above equation. In these cases, the following equation can be used to calculate the maximum total salinity: y = (a +bx +cx2) -1 where y is salinity, x is Tm-HH, a = 0. 057184817, b = 0. 00078565757, and c = 5. 7262766E-6. Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl2 binary side in the H2O-NaCl-CaCl2 ternary system, the errors in salinity calculation introduced by the above approximation are small ( less than 2 wt% ). A Windows program for calculation of XNacl and salinity is available at: http ://uregina. ca/~ chiguox.

  6. Nitrate sorption on activated carbon modified with CaCl2: Equilibrium, isotherms and kinetics

    Zanella Odivan


    Full Text Available In this study, nitrate (NO3- removal from aqueous solutions was investigated using granular activated carbon (GAC modified with CaCl2. Batch sorption studies were performed as a function of sorbent dose, initial nitrate concentration and pH. Sorption was maximized between pH 3 and 9. Studies on the effect of pH showed that the ion exchange mechanism might be involved in the sorption process. The percentage of nitrate removed increased with increasing sorbent concentration, and the ideal sorbent dose was found to be 20 g•L-1. Four isotherm models-Langmuir, Freundlich, Redlich-Peterson and Sips-were used to fit the experimental data. The Redlich-Peterson isotherm model explained the sorption process well and showed the best coefficient of determination (0.9979 and Chi-square test statistic (0.0079. Using the Sips isotherm model, the sorption capacity (qe was found to be 1.93 mg nitrate per g of sorbent. Kinetic experiments indicated that sorption was a fast process, reaching equilibrium within 120 min. The nitrate sorption kinetic data were successfully fitted to a pseudo-second-order kinetic model. The overall results demonstrated potential applications of modified GAC for nitrate removal from aqueous solutions.

  7. Solid-state polymerisation via [2+2] cycloaddition reaction involving coordination polymers.

    Medishetty, Raghavender; Park, In-Hyeok; Lee, Shim Sung; Vittal, Jagadese J


    Highly crystalline metal ions containing organic polymers are potentially useful to manipulate the magnetic and optical properties to make advanced multifunctional materials. However, it is challenging to synthesise monocrystalline metal complexes of organic polymers and single-phase hybrid materials made up of both coordination and organic polymers by traditional solution crystallisation. This requires an entirely different approach in the solid-state by thermal or photo polymerisation of the ligands. Among the photochemical methods available, [2+2] cycloaddition reaction has been recently employed to generate cyclobutane based coordination polymers from the metal complexes. Cyclobutane polymers have also been integrated into coordination polymers in this way. Recent advancements in the construction of polymeric chains of cyclobutane rings through photo-dimerisation reaction in the monocrystalline solids containing metal complexes, coordination polymers and metal-organic framework structures are discussed here.

  8. Preparation of pre-reduced pellet using pyrite cinder containing nonferrous metals with high temperature chloridizingreduction roasting technology—Effect of CaCl2additive

    陈栋; 朱德庆; 洪澜; 陈瑶; 许继芳; 伍凌


    The role of CaCl2 during the high temperature chloridizing-reduction roasting process was investigated, aiming at acquiring high strength blast furnace burden with high iron grade and low nonferrous metals content. The effects of CaCl2 dosage on pelletizing, preheating and reduction were investigated. The results show that CaCl2 can improve the wet drop strength but reduces the thermostability of pyrite cinder green balls. When the dosage of CaCl2 exceeds 1%, the compressive strength of preheated pellets decreases while the growth of iron oxide particles is improved. Furthermore, the compressive strength of pre-reduced pellets increases but the metallization degree of pre-reduced pellets decreases with CaCl2 additive. The removal tests indicate that Zn can be removed completely without CaCl2 additive, Cu is removed only under the condition with CaCl2 additive and part of Pb must be removed by CaCl2 additive.

  9. Preparation of pre-reduced pellet using pyrite cinder containing nonferrous metals with high temperature chloridizing- reduction roasting technology-Effect of CaCl2 additive

    陈栋; 朱德庆; 洪澜; 陈瑶; 许继芳; 伍凌


    The role of CaCl2 during the high temperature chloridizing-reduction roasting process was investigated, aiming at acquiring high strength blast furnace burden with high iron grade and low nonferrous metals content. The effects of CaCl2 dosage on pelletizing, preheating and reduction were investigated. The results show that CaCl2 can improve the wet drop strength but reduces the thermostability of pyrite cinder green balls. When the dosage of CaCl2 exceeds 1%, the compressive strength of preheated pellets decreases while the growth of iron oxide particles is improved. Furthermore, the compressive strength of pre-reduced pellets increases but the metallization degree of pre-reduced pellets decreases with CaCl2 additive. The removal tests indicate that Zn can be removed completely without CaCl2 additive, Cu is removed only under the condition with CaCl2 additive and part of Pb must be removed by CaCl2 additive.

  10. Path optimization by a variational reaction coordinate method. II. Improved computational efficiency through internal coordinates and surface interpolation.

    Birkholz, Adam B; Schlegel, H Bernhard


    Reaction path optimization is being used more frequently as an alternative to the standard practice of locating a transition state and following the path downhill. The Variational Reaction Coordinate (VRC) method was proposed as an alternative to chain-of-states methods like nudged elastic band and string method. The VRC method represents the path using a linear expansion of continuous basis functions, allowing the path to be optimized variationally by updating the expansion coefficients to minimize the line integral of the potential energy gradient norm, referred to as the Variational Reaction Energy (VRE) of the path. When constraints are used to control the spacing of basis functions and to couple the minimization of the VRE with the optimization of one or more individual points along the path (representing transition states and intermediates), an approximate path as well as the converged geometries of transition states and intermediates along the path are determined in only a few iterations. This algorithmic efficiency comes at a high per-iteration cost due to numerical integration of the VRE derivatives. In the present work, methods for incorporating redundant internal coordinates and potential energy surface interpolation into the VRC method are described. With these methods, the per-iteration cost, in terms of the number of potential energy surface evaluations, of the VRC method is reduced while the high algorithmic efficiency is maintained.

  11. Simulations of Pore Formation in Lipid Membranes: Reaction Coordinates, Convergence, Hysteresis, and Finite-Size Effects.

    Awasthi, Neha; Hub, Jochen S


    Transmembrane pores play an important role in various biophysical processes such as membrane permeation, membrane fusion, and antimicrobial peptide activity. In principal, all-atom molecular dynamics (MD) simulations provide an accurate model of pore formation in lipid membranes. However, the free energy landscape of transmembrane pore formation remains poorly understood, partly because potential of mean force (PMF) calculations of pore formation strongly depend on the choice of the reaction coordinate. In this study, we used umbrella sampling to compute PMFs for pore formation using three different reaction coordinates, namely, (i) a coordinate that steers the lipids in the lateral direction away from the pore center, (ii) the distance of a single lipid phosphate group from the membrane center, and (iii) the average water density inside a membrane-spanning cylinder. Our results show that while the three reaction coordinates efficiently form pores in membranes, they suffer from strong hysteresis between pore-opening and pore-closing simulations, suggesting that they do not restrain the systems close to the transition state for pore formation. The two reaction coordinates that act via restraining the lipids lead to more pronounced hysteresis compared with the coordinate acting on the water molecules. By comparing PMFs computed from membranes with different numbers of lipids, we observed significant artifacts from the periodic boundary conditions in small simulation systems. Further analysis suggests that the formation and disruption of a continuous hydrogen-bonding network across the membrane corresponds to the transition state for pore formation. Our study provides molecular insights into the critical steps of transmembrane pore formation, and it may guide the development of efficient reaction coordinates for pore formation.

  12. Distribution threshold values of CaCl2 onto the 10X-zeolite and macro-pore silica gel


    The calcium chloride used for adsorption separation of ammonia is promising for its large adsorptive capacity and lower desorption temperature,but difficult to develop because of the liable expansion,lump and chip in the adsorption/desorption process.Composite adsorbents made by monolayer dis-persion of calcium chloride onto carriers with high surface areas exhibit better adsorptive capacity and stability.Several models were developed to confirm the maximum monolayer dispersion capacity of calcium chloride onto the carriers(the distribution threshold value),and the closely packed monolayer dispersion model was considered the most suitable for this study.The distribution threshold values given by this model were 0.60 g CaCl2/(g 10X-zeolite) and 0.38 g CaCl2/(g SiO2).When the divalent salt was dispersed onto the carriers,however,anions were separated into two types,causing that the en-tropy of the system tended to increase and the system was not stable.To minimize the entropy,a new model was put forward as the modified closely packed monolayer dispersion model.Based on this model,the distribution threshold values are 0.52 g CaCl2/(g 10X-zeolite) and 0.33 g CaCl2/(g SiO2),re-spectively.The distribution threshold values were also gained experimentally by XRD quantitative phase analysis:0.61 g CaCl2/(g 10X-zeolite) and 0.31 g CaCl2/(g SiO2).Comparison between experi-mental values of distribution threshold with theoretical ones based on two different model showed that the closely packed monolayer dispersion model fits the monolayer dispersion of calcium chloride onto micro-pore carrier - 10X-zeolite,and the modified closely packed monolayer dispersion model is more suitable for the bigger aperture carrier - macro-pore silica gel.

  13. Activity coefficients of CaCl{sub 2} in (maltose + water) and (lactose + water) mixtures at 298.15 K

    Zhuo Kelei [School of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China)], E-mail:; Liu Hongxun; Zhang Honghao; Liu Yaohui; Wang Jianji [School of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan 453007 (China)


    Activity coefficients of CaCl{sub 2} in disaccharide {l_brace}(maltose, lactose) + water{r_brace} mixtures at 298.15 K were determined by cell potentials. The molalities of CaCl{sub 2} ranged from about 0.01 mol . kg{sup -1} to 0.20 mol . kg{sup -1}, the mass fractions of maltose from 0.05 to 0.25, and those of lactose from 0.025 to 0.125. The cell potentials were analyzed by using the Debye-Hueckel extended equation and the Pitzer equation. The activity coefficients obtained from the two theoretical models are in good agreement with each other. Gibbs free energy interaction parameters (g{sub ES}) and salting constants (k{sub S}) were also obtained. These were discussed in terms of the stereo-chemistry of saccharide molecules and the structural interaction model.

  14. Facile fabrication of robust silk nanofibril films via direct dissolution of silk in CaCl2-formic acid solution.

    Zhang, Feng; You, Xinran; Dou, Hao; Liu, Zhi; Zuo, Baoqi; Zhang, Xueguang


    In this study, we report for the first time a novel silk fibroin (SF) nanofibrous films with robust mechanical properties that was fabricated by directly dissolving silk in CaCl2-formic acid solution. CaCl2-FA dissolved silk rapidly at room temperature, and more importantly, it disintegrated silk into nanofibrils instead of separate molecules. The morphology of nanofibrils crucially depended on CaCl2 concentrations, which resulted in different aggregation nanostructure in SF films. The SF film after drawing had maximum elastic modulus, ultimate tensile strength, and strain at break reaching 4 GPa, 106 MPa, and 29%, respectively, in dry state and 206 MPa, 28 MPa, and 188%, respectively, in wet state. Moreover, multiple yielding phenomena and substantially strain-hardening behavior was also observed in the stretched films, indicating the important role played by preparation method in regulating the mechanical properties of SF films. These exceptional and unique mechanical properties were suggested to be caused by preserving silk nanofibril during dissolution and stretching to align these nanofibrils. Furthermore, the SF films exhibit excellent biocompatibility, supporting marrow stromal cells adhesion and proliferation. The film preparation was facile, and the resulting SF films manifested enhanced mechanical properties, unique nanofibrous structures, and good biocompability.

  15. Phase transition between the CaCl2-type and α-PbO2-type structures of germanium dioxide

    Ono, Shigeaki; Tsuchiya, Taku; Hirose, Kei; Ohishi, Yasuo


    Observations of the phase transition between the CaCl2-type (Pnnm) and α-PbO2-type (Pbcn) structures of germanium dioxide (GeO2) were carried out using quench and in situ x-ray diffraction methods in a laser-heated diamond anvil cell (LHDAC). First-principle theoretical simulations were also performed to complement the experimental results. The experiments showed that the transition had a positive dP/dT dependence. The phase boundary between the CaCl2-type and α-PbO2-type structures in the temperature range 1500 2400 K was determined to be P (GPa)=(53±3)+(0.011±0.005)(T-1800) (K) based on the equation of state of platinum and the ruby scale. The positive slope of the transition is consistent with the known phase boundary between the CaCl2-type and α-PbO2-type structures of tin dioxide (SnO2) as germanium dioxide analog and theoretical simulation results. However, our results do not agree with the slope of the phase boundary of silica (SiO2), which has been reported to have a negative slope.

  16. Rate constant and reaction coordinate of Trp-cage folding in explicit water

    Juraszek, J.; Bolhuis, P.G.


    We report rate constant calculations and a reaction coordinate analysis of the rate-limiting folding and unfolding process of the Trp-cage mini-protein in explicit solvent using transition interface sampling. Previous transition path sampling simulations revealed that in this (un)folding process the

  17. The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2-HCl solutions

    Feldmann, Thomas; Demopoulos, George P.


    The crystal growth kinetics of calcium sulfate α-hemihydrate (α-HH) in nearly constant supersaturated HCl-CaCl2 solutions were investigated. Two types of solutions were used, the first had a low HCl (1.4 mol/L) and high CaCl2 (2.8 mol/L) concentration and the second had a high HCl (5.6 mol/L) and low CaCl2 (0.7 mol/L) concentration. These conditions were chosen to represent the first and last stage of a newly developed stage-wise HCl regeneration process. The seeded growth experiments were carried out in a stirred, temperature controlled semi-batch reactor in which supersaturation was kept constant by simultaneous addition of CaCl2 and Na2SO4 solutions. The influence of the following parameters on α-HH crystal growth was studied: temperature (70-95 °C), specific power input of stirring (0.02-1.29 W/kg) and equimolar inflow rate of CaCl2 and Na2SO4 (0-0.6 mol/h). The crystal growth rate was derived from particle size distribution measurements made with the laser light diffraction technique. It was found that the surface area normalized crystal growth rate increased linearly with the molar inflow rate up to 0.3 mol/h, at higher inflow rates no further increase of the growth rate was observed. Temperature and specific power input, within the investigated ranges, did not show a marked effect on the growth rate, attributable to a diffusion/adsorption controlled growth process. An interesting finding of the present research is the establishment of a positive relationship between the narrowing of the width of the particle size distribution with increasing crystal growth rate. The results show that the resulting particle size distribution is positively related to the reagent inflow rate, a finding that can be applied to the industrial design and scale-up of the α-HH crystallization/HCl regeneration process.

  18. Computing the Free Energy along a Reaction Coordinate Using Rigid Body Dynamics.

    Tao, Peng; Sodt, Alexander J; Shao, Yihan; König, Gerhard; Brooks, Bernard R


    The calculations of potential of mean force along complex chemical reactions or rare events pathways are of great interest because of their importance for many areas in chemistry, molecular biology, and material science. The major difficulty for free energy calculations comes from the great computational cost for adequate sampling of the system in high-energy regions, especially close to the reaction transition state. Here, we present a method, called FEG-RBD, in which the free energy gradients were obtained from rigid body dynamics simulations. Then the free energy gradients were integrated along a reference reaction pathway to calculate free energy profiles. In a given system, the reaction coordinates defining a subset of atoms (e.g., a solute, or the quantum mechanics (QM) region of a quantum mechanics/molecular mechanics simulation) are selected to form a rigid body during the simulation. The first-order derivatives (gradients) of the free energy with respect to the reaction coordinates are obtained through the integration of constraint forces within the rigid body. Each structure along the reference reaction path is separately subjected to such a rigid body simulation. The individual free energy gradients are integrated along the reference pathway to obtain the free energy profile. Test cases provided demonstrate both the strengths and weaknesses of the FEG-RBD method. The most significant benefit of this method comes from the fast convergence rate of the free energy gradient using rigid-body constraints instead of restraints. A correction to the free energy due to approximate relaxation of the rigid-body constraint is estimated and discussed. A comparison with umbrella sampling using a simple test case revealed the improved sampling efficiency of FEG-RBD by a factor of 4 on average. The enhanced efficiency makes this method effective for calculating the free energy of complex chemical reactions when the reaction coordinate can be unambiguously defined by a

  19. El CaCl2 en la vida florero de gerbera: pigmentos, fenoles, lignina y anatomía del escapo CaCl2 in gerbera vase life: pigments, phenols, lignin and scape anatomy

    Susana González-Aguilar


    Full Text Available Gerbera jamesonii presenta una vida florero corta caracterizada por el doblado del tallo floral (escapo. Con el objetivo de alargar la vida florero de gerbera se probaron tres concentraciones de CaCl2 (0.1, 0.5 y 1.0% en las variedades Duela y Shirlaine. Las concentraciones 0.5% y 1.0% redujeron la pérdida de peso de la flor entera y lígulas en comparación con el testigo. La concentración 0.5% fue el mejor tratamiento, aumentó la vida media florero (25 d Duela y 24 d Shirlaine. Los tallos florales tratados con CaCl2 acumularon más Ca+2 en el ápice (25.33 ug g-¹ Duela y 64.0 ug g-1 Shirlaine, permaneciendo erectos por más tiempo que el testigo (9.67 ug g-¹ Duela y 13.67 ug g-¹ Shirlaine. Con la concentración 0.5% se hizo un segundo experimento para evaluar los cambios en concentración de carotenos, antocianinas (pelargonidina, cianidina y fenoles totales de las lígulas. Las antocianinas de Shirlaine, no cambiaron entre tratamientos. Los fenoles aumentaron 2 1% en Shirlaine y 40% en Duela con respecto a su concentración inicial, en contraste los carotenos disminuyeron al fin de la vida florero 60% y 3 5 %. En Duela el tejido interfascicular es más lignificado que en Shirlaine confiriéndole mayor resistencia. El área relativa (% lignificada de la región media del escapo fue mayor en Duela (7% que en Shirlaine (4%. La mayor resistencia del tallo de Duela es explicada por su anatomía y lignificación pero el CaCl2 fue efectivo para retrasar la senescencia y el doblado del escapo en las dos variedades.Gerbera jamesonii has short vase life characterized by bending of floral stem (scape. With the purpose to extend gerbera vase life, three different CaCl2 concentrations (0.1, 0.5 and 1.0% were tested in Duela and Shirlaine varieties. Weight loss of whole flower and ligules was less than in control with 0.5% and 1.0%concentrations. Whole flower and ligules weight was reduced with 0.5% and 1.0% concentrations when compared to control. 0

  20. The influence of gymnastics in motor coordination and reaction time in urban public bus drivers

    Stela Paula Mezzomo


    Full Text Available This study investigated the influence of labour gymnastics (LG on bus drivers' basic skills such as reaction time and gross motor coordination. Sixty male bus drivers (37.06 ± 7.66 years old from two bus lines in the city of Santa Maria (RS took part of this study. The participants were split into two groups, experimental group (EG and control group (CG. Subjects that were part of the EG took part in a LG intervention program, 2-3 times a week, over a year. Gross motor coordination was assessed by BURPEE Protocol (Johnson & Nelson, 1979, whereas reaction time by software providing a visual stimulus. Data normality was checked through Shapiro-Wilk test, which pointed to normal distribution only for the variables simple reaction time (SRT and choice reaction time (CRT in the EG. Therefore the non-parametric Mann-Whitney U test was selected to compare differences between groups. A statistically significant difference for gross motor coordination was found (z= −2.525, p= 0.012, suggesting the effectiveness of LG to improve motor skills. As regards SRT and CRT, no significant difference was found, in spite of better outcomes having been recorded after the LG program.

  1. CaCl2对北海道黄杨叶片抗冷生理的影响%Effects of CaCl2on Cold Resistance Physiology of Euonymus japonicus cv.‘Cuzhi' Leaves

    杨蕊; 张睿鹂; 杨文莉; 关雪莲


    为了探索Ca2+对植物抗寒性的影响,了解植物抗寒机理,在低温胁迫前用不同浓度CaCl2溶液浇灌北海道黄杨扦插植株,然后对植株进行4℃低温胁迫.研究不同浓度CaCl2对4℃低温胁迫过程中叶片渗透调节物质,抗氧化酶(SOD、POD和CAT)活性以及丙二醛含量的影响.结果表明,用10 mmol/L CaCl2处理北海道黄杨植株,能显著提高低温胁迫过程中叶片脯氨酸和可溶性蛋白含量,改变抗氧化酶活性,降低MDA含量.%For investigating the effects of calcium chloride on cold resistance and the mechanism of the plant's cold resistance, cuttings of Euonymus japonic us cv. 'Cuzhi' were irrigated by calcium chloride with different concentrations before cold stress. Then they were transferred at 4 ℃. The osmo-regulatory substances, activity of antioxidant enzymes (SOD, POD, CAT) and MDA content of leaves at 4 ℃ were observed. The results showed that 10 mmol/L of calcium chloride could significantly increase the content of the proline and soluble protein,change the activity of antioxidant enzymes, and decrease the content of MDA during cold stress.

  2. Dynamic reaction coordinate in thermally fluctuating environment in the framework of the multidimensional generalized Langevin equations.

    Kawai, Shinnosuke; Komatsuzaki, Tamiki


    A framework recently developed for the extraction of a dynamic reaction coordinate to mediate reactions buried in a multidimensional Langevin equation is extended to the generalized Langevin equations without a priori assumption of the forms of the potential (in general, nonlinearly coupled systems) and the friction kernel. The equation of motion with memory effect can be transformed into an equation without memory at the cost of an increase in the dimensionality of the system, and hence the theoretical framework developed for the (nonlinear) Langevin formulation can be generalized to the non-Markovian process with colored noise. It is found that the increased dimension can be physically interpreted as effective modes of the fluctuating environment. As an illustrative example, we apply this theory to a multidimensional generalized Langevin equation for motion on the Müller-Brown potential surface with an exponential friction kernel. Numerical simulations find a boundary between the highly reactive region and the less reactive region in the space of initial conditions. The location of the boundary is found to depend significantly on both the memory kernel and the nonlinear couplings. The theory extracts a reaction coordinate whose sign determines the fate of the reaction taking into account thermally fluctuating environments, memory effect, and nonlinearities. It is found that the location of the boundary of reactivity is satisfactorily reproduced as the zero of the statistical average of the new reaction coordinate, which is an analytical functional of both the original position coordinates and velocities of the system, and of the properties of the environment.

  3. PENGARUH CaCl2 DAN EDIBLE FILM TERHADAP PENGHAMBATAN CHILLING INJURY BUAH NANGKA KUPAS [Effect of CaCl2 and Edible Film on Chilling Injury Inhibition of fresh-cut Jackfruits

    Ida Bagus Banyuro Partha1


    Full Text Available Effect of CaCl2 soaking and edible film coating to delay or inhibit chilling injury of freshly-cut jackfruit has been studied. The onset of chilling injury was monitored based on sadden increase of ethylene emission as measured on-line using CO2-laser driven photoacoustic spectrometer. Freshly cut edible part of ripe jackfruit was used as the research material. The fruit was soaked in 0%, 1%, 1,5%, 2% of CaCl2 for 15 minutes. After rinsing, sample were divided into two parts each for edible coating and control. The edible film was prepared by soaking of the samples for 30 seconds in solution of white bean (Phaseolus lunatus, L. edible coating, which was derived from our previous research. The samples were devided into two parts for destructive and non destructive analysis. Both were then stored at 4oC for 3 days, at which time the normal fruit suffer from chilling injury. For the non-destructive analysis, the samples were individually put in special cuvet and a flow-trough air system was connected to each cuvet for on-line ethylene monitoring. Data of real-time ethylene emission were collected automatically every 120 minutes during the three day cold storage. The other set of samples were put in a plascic bag and stored at 4oC for 3 days period. At the end of cold stored, the samples were let to adjust to room temperature for 1 hr before subjected to respiration rate, reducing sugars, total acidity, and texture analysis. Result indicated that soaking with CaCl2 and edible film coating of freshly-cut jackfruit delayed the on-set of chilling injury as indicated by late increase of ethylene emission. Based on pattern of ethylene emission during the three day storage and their respiration rate, the best treatment to delay chilling injury of fresly-cut jackfruit was soaking in CaCl2 2% in combination with edible film coating.

  4. Path optimization by a variational reaction coordinate method. I. Development of formalism and algorithms.

    Birkholz, Adam B; Schlegel, H Bernhard


    The development of algorithms to optimize reaction pathways between reactants and products is an active area of study. Existing algorithms typically describe the path as a discrete series of images (chain of states) which are moved downhill toward the path, using various reparameterization schemes, constraints, or fictitious forces to maintain a uniform description of the reaction path. The Variational Reaction Coordinate (VRC) method is a novel approach that finds the reaction path by minimizing the variational reaction energy (VRE) of Quapp and Bofill. The VRE is the line integral of the gradient norm along a path between reactants and products and minimization of VRE has been shown to yield the steepest descent reaction path. In the VRC method, we represent the reaction path by a linear expansion in a set of continuous basis functions and find the optimized path by minimizing the VRE with respect to the linear expansion coefficients. Improved convergence is obtained by applying constraints to the spacing of the basis functions and coupling the minimization of the VRE to the minimization of one or more points along the path that correspond to intermediates and transition states. The VRC method is demonstrated by optimizing the reaction path for the Müller-Brown surface and by finding a reaction path passing through 5 transition states and 4 intermediates for a 10 atom Lennard-Jones cluster.


    施理; 叶桂安; 孙勇; 张亚力; 张振书; 张万岱; 周殿元



  6. Reaction Rate Theory in Coordination Number Space: An Application to Ion Solvation

    Roy, Santanu; Baer, Marcel D.; Mundy, Christopher J.; Schenter, Gregory K.


    Understanding reaction mechanisms in many chemical and biological processes require application of rare event theories. In these theories, an effective choice of a reaction coordinate to describe a reaction pathway is essential. To this end, we study ion solvation in water using molecular dynamics simulations and explore the utility of coordination number (n = number of water molecules in the first solvation shell) as the reaction coordinate. Here we compute the potential of mean force (W(n)) using umbrella sampling, predicting multiple metastable n-states for both cations and anions. We find with increasing ionic size, these states become more stable and structured for cations when compared to anions. We have extended transition state theory (TST) to calculate transition rates between n-states. TST overestimates the rate constant due to solvent-induced barrier recrossings that are not accounted for. We correct the TST rates by calculating transmission coefficients using the reactive flux method. This approach enables a new way of understanding rare events involving coordination complexes. We gratefully acknowledge Liem Dang and Panos Stinis for useful discussion. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. SR, CJM, and GKS were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. MDB was supported by MS3 (Materials Synthesis and Simulation Across Scales) Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated by Battelle for the U.S. Department of Energy.

  7. Regeneration of high-quality silk fibroin fiber by wet spinning from CaCl2-formic acid solvent.

    Zhang, Feng; Lu, Qiang; Yue, Xiaoxiao; Zuo, Baoqi; Qin, Mingde; Li, Fang; Kaplan, David L; Zhang, Xueguang


    Silks spun by silkworms and spiders feature outstanding mechanical properties despite being spun under benign conditions. The superior physical properties of silk are closely related to its complicated hierarchical structures constructed from nanoscale building blocks, such as nanocrystals and nanofibrils. Here, we report a novel silk dissolution behavior, which preserved nanofibrils in CaCl2-formic acid solution, that enables spinning of high-quality fibers with a hierarchical structure. This process is characterized by simplicity, high efficiency, low cost, environmental compatibility and large-scale industrialization potential, as well as having utility and potential for the recycling of silk waste and the production of silk-based functional materials.

  8. Yttria-stabilized zirconia as membrane material for electrolytic deoxidation of CaO-CaCl{sub 2} melts

    Martin, A.; Poignet, J. C.; Fouletier, J. [Univ Grenoble, LEPMI, CNRS, INPG, UJF, F-38402 St Martin Dheres (France); Allibert, M. [LPSC, F-38026 Grenoble 1 (France); Lambertin, D. [SPDE, CEA Marcoule, F-30207 Bagnols Sur Ceze (France); Bourges, G. [SRPU, CEA Valduc, F-21120 Is Sur Tille (France)


    This article is devoted to the study of the stability of an yttria-stabilized zirconia membrane used in the electrolysis of molten CaCl{sub 2}-CaO mixtures at 850 degrees C. Intentiostatic and potentiostatic electrolysis were carried for periods ranging from 10 to 20 h. Post-mortem composition profiles across the zirconia membrane were determined using Raman spectroscopy and microprobe analysis. The membrane degradation was analyzed in terms of synergetic parameters, i. e., chemical, electrochemical, and thermomechanical effects. (authors)

  9. Efecto de la inyección de CaCl2 sobre la suavidad del corte de solomo (Outside

    Alejandro Chac\\u00F3n-Villalobos


    Full Text Available Efecto de la inyección de CaCl2 sobre la suavidad del corte de solomo (Outside. Con el objetivo de determinar el efecto del CaCl2 sobre la suavidad del corte de solomo se utilizaron 100 so lomos (outside con pe so me dio de 2,9 kg, en Alajuela y San José en el año 2000. Ochen ta fue ron inyectados mecánicamente con CaCl2 (3% en una can ti dad equi va len te al 5% del pe so de ca da pieza, empacados al vacío, madurados a 7 ºC durante siete días, y divididos aleatoria mente en cuatro subgrupos de 20 unidades. Un subgrupo se con ge ló a –25 ºC du ran te un mes. El se gun do y ter cero se cocinaron por inmersión en agua ca liente hasta alcanzar una temperatura interna estimada de 70 ºC. Al terminar la cocción el tercer subgrupo se congeló como se describió antes. El cuar to sub gru po so lo se ma du ró y vein te pie zas fres cas constituyeron el grupo control. Se determinó la fuerza de cor te pa ra las 100 pie zas em plean do el mé to do de la Ame rican Meat Scien ce As so cia tion. El pH de las pie zas fres cas y de aquellas sometidas a los procesos de maduración fue determinado. Se estimó la calidad microbiológica y las pérdi das de peso de cada tratamiento. El solomo fresco presentó un pH ba jo (5,4 que no es significativamente incrementado por la maduración con CaCl2 (p > 0,05. Los tra tamientos de cocción presentaron mayores pérdidas de peso y menores mejorías en la sua vidad. To dos los tratamientos aumentaron la sua vi dad ini cial del so lo mo (7,45 kg/cm2 y pre sen ta ron recuentos microbianos aceptables. La inyección seguida de empacado al va cío y maduración generó mejores resultados en la sua vi dad fi nal (3,81 kg/cm2.

  10. Ultrastructural and intracellular chemical changes of a novel halophilic strain V430 of Staphylococcus saprophyticus under CaCl2 stress.

    Xin, Xin; Wang, Yanxin


    Observation of the ultrastructural and intracellular chemical changes of CaCl2-tolerant strains is important both for understanding their adaptation mechanism under high salt stress and for providing theoretical basis of their application in treating high-CaCl2 wastewaters. A novel strain V 430 isolated by us has been successfully used to decrease the chemical oxygen demand (COD) concentration of diosgenin wastewater from 20 g l-1 to less than 0.5 g l-1. For this study, strain V430 was incubated in culture media of different CaCl2 concentrations (up to 9.0%). Strain V430 cells incubated in media of high CaCl2 concentration excreted extracellular substances and accumulated intracellular Ca2+ and K+ and free amino acids. The levels of intracellular cations and free amino acids increased with increase in CaCl2 concentration of the medium. The increase in total free amino acids was mostly due to accumulation of glutamic acid. The strain cells under 9.0% CaCl2 stress took up K+ in a short time, while accumulation of Ca2+ proceeded over the whole growth process.

  11. Effect of Ascorbic Acid, CaCl2, and Hydrogen Peroxide on Mushrooms (Agaricus bisporus Shelf Life

    F. Sarlak


    Full Text Available Mushrooms are characterized by a very short shelf life and browning, weight-loss and microbial infections are known as the most deteriorating postharvest modifications in the mushrooms, leading to notable economic losses. In this study, the effects of some postharvest treatments including calcium chloride (0.30 and 0.45%, ascorbic acid (1, 2 and 3 mM and hydrogen peroxide (1% on increasing mushroom shelf life were evaluated. Mushrooms were dipped in the solution treatments for 2 min, then dried at room temperature and packed in polyethylene container by cellophane cover and were stored at 4°C. Some qualitative and quantitative parameters were measured on 8th and 16th days of storage. Results showed that, 0.45% CaCl2, as well as 2 and 3 mM ascorbic acid and 1% peroxide hydrogen effectively maintained mushrooms marketability and kept the cap closed. CaCl2 treatment was effective in extending the postharvest life of mushrooms due to reducing weight loss, maintaining firmness, reducing electrolyte leakage and lowering bacterial populations. Ascorbic acid was an effective treatment in reducing the weight loss, electrolyte leakage, bacterial populations and, thereby, maintaining the firmness. Hydrogen peroxide treatment improved the postharvest quality of mushrooms only through reducing bacterial populations.

  12. Long-Term Corrosion Behavior of Alloy 22 in 5M CaCl2 at 120 C

    J.C. Estill; G.A. Hust; K.J. Evans; M.L. Stuart; R.B. Rebak


    In conditions where tight crevices exist in hot chloride containing solutions Alloy 22 may suffer crevice corrosion. The occurrence (or not) of crevice corrosion in a given environment (e.g, salt concentration and temperature), is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}). This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of creviced Alloy 22 specimens in 5 M calcium chloride (CaCl{sub 2}) at 120 C. Tested specimens included non-creviced rods and multiple creviced assemblies (MCA) both non-welded (wrought) and welded. Results show that Alloy 22 suffers crevice corrosion under the open circuit conditions in the aerated hot CaCl{sub 2} brine. However, after more than a year of immersion the propagation of crevice corrosion was not significant. The general corrosion rate decreased or remained unchanged as the immersion time increased. For rods and MCA specimens, the corrosion rate was lower than 100 nm/year after more than a year immersion time.

  13. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals.

    Tu, Renyong; Xie, Yi; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; Trizio, Luca De; Manna, Liberato


    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e., with coordination number 4), such as Cd(2+) or Hg(2+), yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd(2+) and Hg(2+) ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2-xTe particles could be more easily deformed to match the anion framework of the metastable wurtzite structures. As hexagonal HgTe had never been reported to date, this represents another case of metastable new phases that can only be accessed by cation exchange. On the other hand, the exchanges involving octahedrally coordinated ions (i.e., with coordination number 6), such as Pb(2+) or Sn(2+), yielded rock-salt polycrystalline PbTe or SnTe nanocrystals with Cu2-xTe@PbTe or Cu2-xTe@SnTe core@shell architectures at the early stages of the exchange process. In this case, the octahedrally coordinated ions are probably too large to diffuse easily through the Cu2-xTe structure: their limited diffusion rate restricts their initial reaction to the surface of the nanocrystals, where cation exchange is initiated unselectively, leading to core@shell architectures. Interestingly, these heterostructures were found to be metastable as they evolved to stable Janus-like architectures if annealed at 200 °C under vacuum.

  14. Influence of the Ion Coordination Number on Cation Exchange Reactions with Copper Telluride Nanocrystals

    Tu, Renyong; Bertoni, Giovanni; Lak, Aidin; Gaspari, Roberto; Rapallo, Arnaldo; Cavalli, Andrea; De Trizio, Luca; Manna, Liberato


    Cu2-xTe nanocubes were used as starting seeds to access metal telluride nanocrystals by cation exchanges at room temperature. The coordination number of the entering cations was found to play an important role in dictating the reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e. with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like heterostructures as intermediates. The formation of Janus-like architectures was attributed to the high diffusion rate of the relatively small tetrahedrally coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and nucleate the CdTe (or HgTe) phase in a preferred region of the host structure. Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe phases rather than the more stable zinc-blende ones, indicating that the anion framework of the starting Cu2- xTe particles could be more easily deformed to match the anion framework of t...

  15. Effects of CaCl2 on osmotic regulators in the leaves of sweet potato under NaCl stress%CaCl2对NaCl胁迫下甘薯幼苗叶片渗透调节物质的影响

    李百伟; 孙存华; 王丹


    @@%以徐薯18为材料,通过浇灌不同浓度(0.6%、1.2%、1.8%) CaCl2研究了NaCl胁迫下CaCl2对甘薯幼苗叶片可溶性糖、可溶性蛋白和脯氨酸含量的影响,结果表明:盐胁迫下添加不同浓度CaCl2后甘薯幼苗叶片的脯氨酸和可溶性糖含量都比未添加的显著升高,顺序为添加1.2% CaCl2>添加1.8% CaCl2>添加0.6% CaCl2,可溶性蛋白含量在加入不同浓度CaCl2后均变化不大.

  16. Reaction between radicals and N-alkoxyamines As coordinated cleavage with fragmentation

    Denisov, E. T.; Shestakov, A. F.


    Quantum chemical calculations of the enthalpy and activation energy of two reactions with MeO{2/⊙} attacking the CH- and CH2-groups of 2,2,6,6-tetramethylpiperidineoxy-2'-butane are performed. It is shown that the cleavage of hydrogen atoms is accompanied by coordinated breaking of N-O-bonds in the former case and C-O-bonds in the latter. Based on the obtained results, a new scheme is proposed for the cyclic mechanism behind the cleavage of chains on nitroxyl radicals in oxidizing hydrocarbons and polymers that agrees with experimental data. At the center of this cyclic mechanism lies the fast exothermic reaction between peroxyl radicals and N-alkoxyamine with the cleavage of H atoms and the coordinated fragmentation of molecules. Using the model of intersecting parabolas, an algorithm for calculating the enthalpies, activation energies, and rate constants of these reactions with the participation of alkyl, alkoxy, aminyl, peroxyl, phenoxyl, thiyl, and hydroxyl radicals is proposed.

  17. The physiological protective effect of CaCl2 on papaya on seedlings stressed by acid rain%CaCl2对番木瓜幼苗酸雨伤害的生理保护效应

    肖艳; 黄建昌


    用30 mmol/L的CaCl2预处理番木瓜(Carica papaya L.)幼苗,结果表明,钙预处理能有效减缓番木瓜幼苗因酸雨胁迫引起的光合速率、叶绿素含量的下降,增加超氧歧化酶(SOD)活性,减少膜质过氧化产物丙二醛(MDA)含量,降低细胞质膜透性,维持细胞汁液pH值稳定性,减轻酸雨对番木瓜幼苗的酸致损伤.

  18. Homogeneous photocatalytic reactions with organometallic and coordination compounds--perspectives for sustainable chemistry.

    Hoffmann, Norbert


    Since the time of Giacomo Ciamician at the beginning of the 20th century, photochemical transformations have been recognized as contributing to sustainable chemistry. Electronic excitation significantly changes the reactivity of chemical compounds. Thus, the application of activation reagents is frequently avoided and transformations can be performed under mild conditions. Catalysis plays a central role in sustainable chemistry. Stoichiometric amounts of activation reagents are often avoided. This fact and the milder catalytic reaction conditions diminish the formation of byproducts. In the case of homogeneous catalysis, organometallic compounds are often applied. The combination of both techniques develops synergistic effects in the sense of "Green Chemistry". Herein, metal carbonyl-mediated reactions are reported. These transformations are of considerable interest for the synthesis of complex polyfunctionalized compounds. Copper(I)-catalyzed [2+2] photocycloaddition gives access to a large variety of cyclobutane derivatives. Currently, a large number of publications deal with photochemical electron-transfer-induced reactions with organometallic and coordination compounds, particularly with ruthenium complexes. Several photochemically induced oxidations can easily be performed with air or molecular oxygen when they are catalyzed with organometallic complexes. Photochemical reaction conditions also play a certain role in C-H activation with organometallic catalysts, for instance, with alkanes, although such transformations are conveniently performed with a variety of other photochemical reactions.

  19. Self-consistent collective coordinate for reaction path and inertial mass

    Wen, Kai


    We propose a numerical method to determine the optimal collective reaction path for the nucleus-nucleus collision, based on the adiabatic self-consistent collective coordinate (ASCC) method. We use an iterative method combining the imaginary-time evolution and the finite amplitude method, for the solution of the ASCC coupled equations. It is applied to the simplest case, the $\\alpha-\\alpha$ scattering. We determine the collective path, the potential, and the inertial mass. The results are compared with other methods, such as the constrained Hartree-Fock method, the Inglis's cranking formula, and the adiabatic time-dependent Hartree-Fock (ATDHF) method.

  20. Casein phosphopeptides and CaCl2 increase penicillin production and cause an increment in microbody/peroxisome proteins in Penicillium chrysogenum.

    Domínguez-Santos, Rebeca; Kosalková, Katarina; García-Estrada, Carlos; Barreiro, Carlos; Ibáñez, Ana; Morales, Alejandro; Martín, Juan-Francisco


    Transport of penicillin intermediates and penicillin secretion are still poorly characterized in Penicillium chrysogenum (re-identified as Penicillium rubens). Calcium (Ca(2+)) plays an important role in the metabolism of filamentous fungi, and casein phosphopeptides (CPP) are involved in Ca(2+) internalization. In this study we observe that the effect of CaCl2 and CPP is additive and promotes an increase in penicillin production of up to 10-12 fold. Combination of CaCl2 and CPP greatly promotes expression of the three penicillin biosynthetic genes. Comparative proteomic analysis by 2D-DIGE, identified 39 proteins differentially represented in P. chrysogenum Wisconsin 54-1255 after CPP/CaCl2 addition. The most interesting group of overrepresented proteins were a peroxisomal catalase, three proteins of the methylcitrate cycle, two aminotransferases and cystationine β-synthase, which are directly or indirectly related to the formation of penicillin amino acid precursors. Importantly, two of the enzymes of the penicillin pathway (isopenicillin N synthase and isopenicillin N acyltransferase) are clearly induced after CPP/CaCl2 addition. Most of these overrepresented proteins are either authentic peroxisomal proteins or microbody-associated proteins. This evidence suggests that addition of CPP/CaCl2 promotes the formation of penicillin precursors and the penicillin biosynthetic enzymes in peroxisomes and vesicles, which may be involved in transport and secretion of penicillin.

  1. The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500°C

    Bischoff, James L.; Rosenbauer, Robert J.; Fournier, Robert O.


    We determined vapor-liquid relations (P-T-x) and derived critical parameters for the system CaCl2-H2O from 380-500??C. Results show that the two-phase region of this system is extremely large and occupies a significant portion of the P-T space to which circulation of fluids in the Earth's crust is constrained. Results also show the system generates significant amounts of HCl (as much as 0.1 mol/kg) in the vapor phase buffered by the liquid at surprisingly high pressures (???230 bars at 380??C, CaCl2: CaCl2 + 2H2O = Ca(OH)2 + 2HCl. We interpret the abundance of HCl in the vapor as due to its preference for the vapor phase, and by the preference of Ca(OH)2 for either the liquid phase or solid. The recent recognition of the abundance of CaCl2 in deep brines of the Earth's crust and their hydrothermal mobilization makes the hydrolysis of CaCl2 geologically important. The boiling of Ca-rich brines produces abundant HCl buffered by the presence of the liquid at moderate pressures. The resultant Ca(OH)2 generated by this process reacts with silicates to form a variety of alteration products, such as epidote, whereas the vapor produces acid-alteration of rocks through which it ascends.

  2. Hydrophobic Encapsulated Phosphonium Salts-Synthesis of Weakly Coordinating Cations and their Application in Wittig Reactions.

    Moritz, Ralf; Wagner, Manfred; Schollmeyer, Dieter; Baumgarten, Martin; Müllen, Klaus


    Large and rigid tetraarylphosphonium tetrafluoroborate salts have been synthesized representing weakly coordinating cations with diameters of several nanometers. Divergent dendritic growth by means of thermal Diels-Alder cycloaddition was employed for the construction of the hydrophobic polyphenylene framework up to the third generation. X-ray crystal structure analysis of first-generation phosphonium tetrafluoroborate supported the rigidity of the non-collapsible shell around the phosphorus center and gave insight into solid-state packing and cation-anion distances. Copper(I)-catalyzed azide-alkyne ligation served as reliable method for the preparation of a first-generation triazolylphenyl hybrid phosphonium cation under mild reaction conditions. Furthermore, from the synthesis of triarylbenzylphosphonium bromides, Wittig precursors with unprecedented bulky substituents in the α-position were accessible. Employment of these precursors under Wittig conditions by treatment with base and subsequent reaction with aldehydes preferentially provided (Z)-olefins with bulky polyphenylene substituents.

  3. Virtual Screening for Transition State Analogue Inhibitors of IRAP Based on Quantum Mechanically Derived Reaction Coordinates.

    Svensson, Fredrik; Engen, Karin; Lundbäck, Thomas; Larhed, Mats; Sköld, Christian


    Transition state and high energy intermediate mimetics have the potential to be very potent enzyme inhibitors. In this study, a model of peptide hydrolysis in the active site of insulin-regulated aminopeptidase (IRAP) was developed using density functional theory calculations and the cluster approach. The 3D structure models of the reaction coordinates were used for virtual screening to obtain new chemical starting points for IRAP inhibitors. This mechanism-based virtual screening process managed to identify several known peptidase inhibitors from a library of over 5 million compounds, and biological testing identified one compound not previously reported as an IRAP inhibitor. This novel methodology for virtual screening is a promising approach to identify new inhibitors mimicking key transition states or intermediates of an enzymatic reaction.

  4. Perspective: Insight into reaction coordinates and dynamics from the potential energy landscape

    Wales, D. J.


    This perspective focuses on conceptual and computational aspects of the potential energy landscape framework. It has two objectives: first to summarise some key developments of the approach and second to illustrate how such techniques can be applied using a specific example that exploits knowledge of pathways. Recent developments in theory and simulation within the landscape framework are first outlined, including methods for structure prediction, analysis of global thermodynamic properties, and treatment of rare event dynamics. We then develop a connection between the kinetic transition network treatment of dynamics and a potential of mean force defined by a reaction coordinate. The effect of projection from the full configuration space to low dimensionality is illustrated for an atomic cluster. In this example, where a relatively successful structural order parameter is available, the principal change in cluster morphology is reproduced, but some details are not faithfully represented. In contrast, a profile based on configurations that correspond to the discrete path defined geometrically retains all the barriers and minima. This comparison provides insight into the physical origins of "friction" effects in low-dimensionality descriptions of dynamics based upon a reaction coordinate.


    雷亚川; 许志强



  6. A microiterative intrinsic reaction coordinate method for large QM/MM systems.

    Polyak, Iakov; Boulanger, Eliot; Sen, Kakali; Thiel, Walter


    Intrinsic reaction coordinate (IRC) computations are a valuable tool in theoretical studies of chemical reactions, but they can usually not be applied in their current form to handle large systems commonly described by quantum mechanics/molecular mechanics (QM/MM) methods. We report on a development that tackles this problem by using a strategy analogous to microiterative transition state optimization. In this approach, the IRC equations only govern the motion of a core region that contains at least the atoms directly involved in the reaction, while the remaining degrees of freedom are relaxed after each IRC step. This strategy can be used together with any existing IRC procedure. The present implementation covers the stabilized Euler, local quadratic approximation, and Hessian predictor-corrector algorithms for IRC calculations. As proof of principle, we perform tests at the QM level on small gas-phase systems and validate the results by comparisons with standard IRC procedures. The broad applicability of the method is demonstrated by IRC computations for two enzymatic reactions using standard QM/MM setups.


    SUN Benhui


    A discussion of the mechanism of nylon 6,6 dissolving process using CaCl2/MeOH as the solvent is presented. The calcium chloride forms a complex compound with nylon6,6 by breaking the hydrogen bonds. The melting point of the CaCl2-nylon 6,6 complex was found to be reduced by 91K relative to the pure nylon 6,6 polymer. The role of methanol is somewhat similar to a catalyst. The results demonstrate that the complexation of a Lewis acid (CaCl2) and a Lewis base (nylon 6, 6) can be used to probe intermolecular interactions such as hydrogen bonding in polymers, to modify the polymer properties and mediate its solubility and processing.

  8. Optimization of pH, temperature and CaCl2 concentrations for Ricotta cheese production from Buffalo cheese whey using Response Surface Methodology.

    Rashid, Abdul Ahid; Huma, Nuzhat; Zahoor, Tahir; Asgher, Muhammad


    The recovery of milk constituents from cheese whey is affected by various processing conditions followed during production of Ricotta cheese. The objective of the present investigation was to optimize the temperature (60-90 °C), pH (3-7) and CaCl2 concentration (2·0-6·0 mm) for maximum yield/recovery of milk constituents. The research work was carried out in two phases. In 1st phase, the influence of these processing conditions was evaluated through 20 experiments formulated by central composite design (CCD) keeping the yield as response factor. The results obtained from these experiments were used to optimize processing conditions for maximum yield using response surface methodology (RSM). The three best combinations of processing conditions (90 °C, pH 7, CaCl2 6 mm), (100 °C, pH 5, CaCl2 4 mm) and (75 °C, pH 8·4, CaCl2 4 mm) were exploited in the next phase for Ricotta cheese production from a mixture of Buffalo cheese whey and skim milk (9 : 1) to determine the influence of optimized conditions on the cheese composition. Ricotta cheeses were analyzed for various physicochemical (moisture, fat, protein, lactose, total solids, pH and acidity indicated) parameters during storage of 60 d at 4 ± 2 °C after every 15 d interval. Ricotta cheese prepared at 90 °C, pH 7 and CaCl2 6 mm exhibited the highest cheese yield, proteins and total solids, while high fat content was recorded for cheese processed at 100 °C, pH 5 and 4 mm CaCl2 concentration. A significant storage-related increase in acidity and NPN was recorded for all cheese samples.

  9. Influência do CaCl2 sobre a qualidade pós-colheita do abacaxi cv. Pérola Influence of CaCl2 on postharvest quality of cv. Pérola pineaplle

    Ana Carla Marques Pinheiro


    Full Text Available Objetivou-se avaliar a influência do cloreto de cálcio (CaCl2 sobre a qualidade pós-colheita de abacaxis cv. Pérola, armazenados sob condições simuladas de transporte marítimo (21 dias a 12±1ºC e comercialização (8 dias a temperatura ambiente, 21 ± 1ºC. O experimento foi conduzido utilizando-se parcelas constituídas de 6 frutos, obedecendo um delineamento experimental inteiramente casualizado e constituindo um fatorial 4 x 6, com 3 repetições, tendo-se quatro níveis de cloreto de cálcio (0, 1, 2 e 3% e seis épocas de análise (0, 21, 23, 25, 27 e 29 dias de armazenamento. Observou-se que a imersão em solução de cloreto de cálcio a 3% promoveu diminuição no índice de escurecimento interno, na área afetada e na intensidade do escurecimento interno, além de determinar uma maior perda de massa e diminuição aparente na solubilização de substâncias pécticas. O cloreto de cálcio, independente do nível, foi efetivo na manutenção da firmeza, embora não tenha afetado significativamente as variáveis pH, acidez titulável, açúcares solúveis totais e pectina total.The goal of this work was to evaluate the influence of the calcium chloride (CaCl2 on the quality of 'Pérola' pineapples, stored under simulated conditions of sea transport (21 days at 12+ 1ºC and marketing (8 days at room temperature, 21 + 1ºC. The experiment was carried out in a completely randomly design. A factorial 4 X 6 (4 levels of calcium chloride: 0, 1, 2 and 3% and six periods of analysis: 0, 21, 23, 25, 27 and 29 days of storage with 3 replicates and six fruits per parcel. The immersion in solution of calcium chloride at 3% promoted decreasing apparent in internal breakdown index, affected area and intensity of internal breakdown, as well as promoted higher mass loss and decreasing in pectic substances solubilization. The calcium chloride, despite the level, was effective in maintaining the firmness, although have not affected significantly

  10. Effects of Exogenous Nitric Oxide and Calcium on Seed Vigor of Salvia miltiorrhizay%外源NO和CaCl2对丹参种子活力的影响

    杨薇; 陈怡平; 贺军民


    用不同浓度的NO供体硝普钠(SNP)和CaCl2浸泡丹参种子,测定其对丹参种子活力的影响.结果表明:低浓度的NO和CaCl2能促进丹参种子萌发,提高丹参种子活力;高浓度的NO和CaCl2则降低了丹参种子活力,其中500μmol/L的SNP和100 mmol/L的CaCl2处理效果最佳.

  11. One-step synthesis of nitrogen-iron coordinated carbon nanotube catalysts for oxygen reduction reaction

    Choi, Woongchul; Yang, Gang; Kim, Suk Lae; Liu, Peng; Sue, Hung-Jue; Yu, Choongho


    Prohibitively expensive precious metal catalysts for oxygen reduction reaction (ORR) have been one of the major hurdles in a wide use of electrochemical cells. Recent significant efforts to develop precious metal free catalysts have resulted in excellent catalytic activities. However, complicated and time-consuming synthesis processes have negated the cost benefit. Moreover, detailed analysis about catalytically active sites and the role of each element in these high-performance catalysts containing nanomaterials for large surface areas are often lacking. Here we report a facile one-step synthesis method of nitrogen-iron coordinated carbon nanotube (CNT) catalysts without precious metals. Our catalysts show excellent long-term stability and onset ORR potential comparable to those of other precious metal free catalysts, and the maximum limiting current density from our catalysts is larger than that of the Pt-based catalysts. We carry out a series of synthesis and characterization experiments with/without iron and nitrogen in CNT, and identify that the coordination of nitrogen and iron in CNT plays a key role in achieving the excellent catalytic performances. We anticipate our one-step process could be used for mass production of precious metal free electrocatalysts for a wide range of electrochemical cells including fuel cells and metal-air batteries.

  12. One-step fabrication of nickel nanocones by electrodeposition using CaCl2·2H2O as capping reagent

    Lee, Jae Min; Jung, Kyung Kuk; Lee, Sung Ho; Ko, Jong Soo


    In this research, a method for the fabrication of nickel nanocones through the addition of CaCl2·2H2O to an electrodeposition solution was proposed. When electrodeposition was performed after CaCl2·2H2O addition, precipitation of the Ni ions onto the (2 0 0) crystal face was suppressed and anisotropic growth of the nickel electrodeposited structures was promoted. Sharper nanocones were produced with increasing concentration of CaCl2·2H2O added to the solution. Moreover, when temperature of the electrodeposition solutions approached 60 °C, the apex angle of the nanostructures decreased. In addition, the nanocones produced were applied to superhydrophobic surface modification using a plasma-polymerized fluorocarbon (PPFC) coating. When the solution temperature was maintained at 60 °C and the concentration of the added CaCl2·2H2O was 1.2 M or higher, the fabricated samples showed superhydrophobic surface properties. The proposed nickel nanocone formation method can be applied to various industrial fields that require metal nanocones, including superhydrophobic surface modification.

  13. Salt exclusion and mycorrhizal symbiosis increase tolerance to NaCl and CaCl2 salinity in ‘Siam Queen’ basil

    A study was conducted to evaluate the effects of salinity on growth and nutrient uptake in basil (Ocimum basilicum L.). Plants were fertilized with a complete nutrient solution and exposed to no, low, or moderate levels of salinity from NaCl or CaCl2. Plants in the control and moderate salinity tre...

  14. 1090K下MgCl2-KCl-CaCl2三元熔盐体系的密度预测

    赵飞; 陈志远; 陈洪智; 赵世强


    镁电解工艺中使用的电解质需要具有合适的密度范围.MgCl2-KCl-CaCl2三元熔盐体系是镁电解质的重要基础三元系.使用了新一代溶液几何模型,预测了这一三元系在1 090 K下的密度.首先勘正了标准数据库中的MgCl2-CaCl2熔盐二元系的密度表达式.对已知3个二元系KCl-CaCl2、MgCl2-CaCl2、KCl-MgCl2数据,采用三次式表达的Redlich-Kister关系式拟合得到了它们的超额密度函数.并计算各组分之间的相似系数.最终获得全组分范围内的三元熔盐体系密度分布图.已知成分点的实验值与预测值之间相对误差在2.21%~0.99%之间,这表明了预测结果的可靠性.

  15. Phase transition and optical properties of CaCl2 under high pressure by ab initio pseudopotential plane-wave calculations

    Liu, Y. H.; Ma, Y. M.; He, Z.; Cui, T.; Liu, B. B.; Zou, G. T.


    We present a detailed investigation of CaCl2 under high pressure in CaCl2 (Pnnm,Z = 2) and α-PbO2 (Pbcn, Z = 4) phases, respectively. Theoretical calculations are performed by using the ab initio pseudopotential plane-wave method based on the density functional method. We estimate the transition pressure between the two phases by the crossing point of their enthalpies, which are equivalent to the Gibbs free energy at zero temperature, after optimizing the structures under high pressure. Our results show that the transition happens at about 2.9 GPa, which is in agreement with the experimental data. We calculate the structural parameters, charge transfers, bond structures, density of states and optical properties. The calculated results show that there are no charge transfers in CaCl2 structure under high pressure. It is found that the transitions from the Cl 3p to Ca 4s and Cl 3s to Ca 3p orbitals contribute mainly to the dielectric function. The optical properties of CaCl2 (Pnnm, Z = 2) do not vary much under pressure. However, some of the dispersion curves of optical constants in the α-PbO2 (Pbcn, Z = 4) phase are changed significantly under pressure.

  16. Phase transition and optical properties of CaCl{sub 2} under high pressure by ab initio pseudopotential plane-wave calculations

    Liu, Y H; Ma, Y M; He, Z; Cui, T; Liu, B B; Zou, G T [National Lab of Superhard Materials, Jilin University, Changchun 130012 (China)


    We present a detailed investigation of CaCl{sub 2} under high pressure in CaCl{sub 2} (Pnnm,Z = 2) and {alpha}-PbO{sub 2} (Pbcn, Z = 4) phases, respectively. Theoretical calculations are performed by using the ab initio pseudopotential plane-wave method based on the density functional method. We estimate the transition pressure between the two phases by the crossing point of their enthalpies, which are equivalent to the Gibbs free energy at zero temperature, after optimizing the structures under high pressure. Our results show that the transition happens at about 2.9 GPa, which is in agreement with the experimental data. We calculate the structural parameters, charge transfers, bond structures, density of states and optical properties. The calculated results show that there are no charge transfers in CaCl{sub 2} structure under high pressure. It is found that the transitions from the Cl 3p to Ca 4s and Cl 3s to Ca 3p orbitals contribute mainly to the dielectric function. The optical properties of CaCl{sub 2} (Pnnm, Z = 2) do not vary much under pressure. However, some of the dispersion curves of optical constants in the {alpha}-PbO{sub 2} (Pbcn, Z = 4) phase are changed significantly under pressure.

  17. The Role of Granule Size on the Kinetics of Electrochemical Reduction of SiO2 Granules in Molten CaCl2

    Yang, Xiao; Yasuda, Kouji; Nohira, Toshiyuki; Hagiwara, Rika; Homma, Takayuki


    As a fundamental study to develop a new process for producing solar-grade silicon, the effect of granule size on the kinetics of the electrochemical reduction of SiO2 granules in molten CaCl2 was investigated. SiO2 granules with different size ranges were electrolyzed in molten CaCl2 at 1123 K (850 °C). The reduction kinetics was evaluated on the basis of the growth rate of the reduced Si layer and the behavior of the current during electrolysis. The results indicated that finer SiO2 granules are more favorable for a high reduction rate because the contact resistance between the bottom Si plate and the reduced Si particles is small and the diffusion of O2- ions in CaCl2 inside the porous Si shell is easy. Electrolysis using SiO2 granules less than 0.1 mm in size maintained a current density of no less than 0.4 A cm-2 within 20 minutes, indicating that the electrochemical reduction of fine SiO2 granules in molten CaCl2 has the potential of becoming a high-yield production process for solar-grade silicon.


    Y. B. Awang


    Full Text Available Fruits harvested at different maturity possess different biochemical constituents and physiological properties that make the fruits may react somewhat differently to the postharvest treatment. A study to examine the activity of Polygalacturonase (PG and Pectin Methylesterase (PME enzymes during storage in dragon fruit (Hylocereus polyrhizus harvested at 28 days (Index 3 and 34 days (Index 5 after anthesis and postharvest treated with 0, 2.5, 5.0 and 7.5 g L-1 CaCl2 was performed. The PG activity was lower in younger fruit and vice-versa for PME activity. Increasing concentration of CaCl2 effectively reduced the activity of both enzymes. PG activity for fruit treated with 0, 5 and 7.5 g L-1 CaCl2 increased linearly with the time of storage while its activity for the fruit treated with 2.5 g L-1 CaCl2 was lower at the beginning of storage. PG activity of Index 5 fruits increased almost linearly during storage while its activity in Index 3 fruits was low at the early days of storage and later continued to increase until day seven. At both maturity indices, the PME activity was low at the early days of storage and later continued to increase until day seven. Overall, results obtained indicated that CaCl2 postharvest treatment reduced both PME and PG activities thus slowing down the softening process giving an evident that calcium possess a distinguishable role in the reducing softening of fruit, regardless of maturity index.

  19. Osmopriming with CaCl2 improves wheat (Triticum aestivum L.) production under water-limited environments.

    Farooq, Shahid; Hussain, Mubshar; Jabran, Khawar; Hassan, Waseem; Rizwan, Muhammad S; Yasir, Tauqeer A


    This 2-year field study investigates the potential of seed priming to mitigate losses caused by drought stress at different phenophases of wheat. Wheat seeds were soaked either in distilled water or in aerated solution of CaCl2 (ψs -1.25 MPa) for 18 h to accomplish hydropriming and osmopriming, respectively. The soil moisture was maintained at 90-100% field capacity (well-watered) or 45-50% field capacity at vegetative (vegetative drought) and reproductive (terminal drought) phases. Allometric traits leaf area index, leaf area duration, and crop growth rate were initially more affected by vegetative drought; however, terminal drought was more severe at later stages. Drought at both phenophases, especially terminal drought, impaired the entire yield-related traits of wheat; however, osmopriming compensated the drought-induced losses up to a certain extent. Osmopriming improved the wheat grain yield, economic benefits, and allometric traits under vegetative and terminal drought as well as well-watered conditions. It is recommended that the physiological, biochemical, and genetic mechanisms of osmopriming must be explored to find more valuable insights for improving wheat productivity.

  20. Direct Extraction of Ti and Ti Alloy from Ti-Bearing Dust Slag in Molten CaCl2

    Chen, Chaoyi; Zhao, Chong; Li, Junqi; Yang, Shufeng


    Using process of solid oxygen-ion conducting membrane (SOM), titanium metal and its alloy can be prepared directly from Ti-bearing dust slag by immersing it in the molten CaCl2 at 1,100℃, which has been proposed by constant voltage of 3.5 V for 2-6 h. The dust slag was ball-milled and pressed into pellets, then employed as the cathode, while the liquid copper, which was saturated with graphite powder and encased in yttria-stabilized zirconia (YSZ) tube, acted as the anode. The effect of forming pressure and electrolytic time on products was analyzed. The results show that the content of titanium increased with electrolytic time and the characteristic morphology presents as granule. Ti-Fe alloy can be obtained from Ti-Fe residue by 6 h electrolysis. For titanium-rich residue, when the forming pressure of pellets decreased from 6 to 3 MPa, only electrolysis for more than 4 h can completely remove the oxygen, and pure titanium is obtained by 6 h electrolysis. Besides, there is an unprecedented finding that the porous cathode is conducive to the removal of impurity elements.

  1. Solution-reaction Calorimetric Study of Coordination Compounds of Rare Earth Perchlorates with Alanine and Imidazole

    ZHAO, Yan-Ru(赵艳茹); HOU, An-Xin(侯安新); DONG, Jia-Xin(董家新); ZHAO, Shun-Sheng(赵顺省); LIU, Yi(刘义); QU, Song-Sheng(屈松生)


    Two coordination compounds of rare earth perchlorates with alanine and imidazole, [RE(Ala)n(Im)(H2O)](ClO4)3(s) (RE=La, n=3; RE=Nd, n=2), have been prepared and characterized. The standard molar enthalpies of reaction for the following two reactions, LaCL·7H2O(s)+3Ala(s)+Im(s)+3NaClO4(s)=[La(Ala).(Im)(H2O)]-(ClO4)3(s)+3NaCl(s)+6H2O(I)(1)and NdCl3·6H2O(s)+2Ala(s)+2Ala(s)+Im(s)+3NaClO4(s)=[Nd(Ala)2(Im)(H2O)]-(ClO4)3(s)+3NaCl(s)+5H2O(l) (2), were determined by solution-reaction calorimetry, at T=298.15 K, as 36.168 ±0.642kJ·mol-1 and 48.590±0.934kJ·mol-1 respectively. From the results and other auxiliary quantities, the standard molar enthalpies of formation of [La(Ala)3(Im)(H2O)](ClO4)3(s) and [Nd(Ala)2(Im)(H2O)] (ClO4)3(s) were derived,△fH(-)m{[La(Ala).(Im)(H2O)](ClO4)3,s}=(-2984.8±1.0)kJ·mol-1 and △fH(-)m{[Nd(Ala).(Im)(H2O)]-(ClO4)3,s}=(-2387.8±0.8)kJ·mol-1, respectively.


    石林; 曾小平; 罗汉金


    通过CaCl2添加剂对KAlSi3O8-CaSO4-CaCO3体系研究反应温度和反应时间的影响研究,结果表明:随着CaCl2加入量的增多,体系的反应温度下降,反应时间缩短,当CaCl2的加入量为10%时,反应温度可降至1 000℃,反应时问降至25 min,此时KAlSi3O8的转化率仍可高达83.24%.研究CaCl2的加入对KAlSi3O8-CaSO4-CaCO3反应体系动力学过程的影响,得出反应体系符合金斯特林格动力学方程:FK(G)=1-2/3G-(1-G) 2/3=KKt,反应受扩散过程控制,计算出当CaCl2的加入量为10%时,体系的表观活化能可从原来的128.921 kJ/mol下降至58.320 kJ/mol.

  3. Stability and Reactivity of Cyclometallated Naphthylamine Complexes in Pd-C Bond Insertion Reactions with Coordinated Alkynylphosphanes

    Chen, Shuli


    Phenylbis(phenylethynyl)phosphane PhP(C≡CPh)2 coordinates regiospecifically to the α-methyl-chiral ortho-platinated and -palladated naphthylamine units at the positions trans to the nitrogen donors. The P→Pt coordination bond is kinetically inert, whereas the P→Pd bond is labile. Upon heating of these phosphane complexes at 70 °C, one of the C≡C bonds in the coordinated PhP(C≡CPh)2 was activated towards an intermolecular Pd-C bond insertion reaction with an external ortho-palladated naphthylamine ring. No intramolecular insertion reaction occurred. In contrast to its palladium analogue, the ortho-platinated ring is not reactive towards coordinated PhP(C≡CPh)2, although it can promote the Pd-C bond insertion reaction. However, despite the high kinetic stability of the P→Pt coordination, the organoplatinum unit is a noticeably weaker activator than its organopalladium counterpart. The chirality of the reacting ortho-metallated naphthylamine ligand exhibited high stereochemical influence on the formation of the new stereogenic phosphorus center during the course of these C-C bond-formation reactions. The coordination chemistry and the absolute stereochemistry of the dimetallic products were determined by single-crystal X-ray crystallographic analysis. The asymmetric monoinsertion of PhP(C≡CPh)2 coordinated to a cyclometallated N,N-dimethyl naphthyl/benzylamine template into the Pd-C bonds of N,N-dimethylnaphthylamine palladacycles has been demonstrated for the synthesis of a variety of new P-stereogenic homo- or heterodimetallic complexes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers

    Silva, Fausthon Fred da; Fernandes de Oliveira, Carlos Alberto; Lago Falcão, Eduardo Henrique [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil); Gatto, Claudia Cristina [Laboratório de Síntese Inorgânica e Cristalografia, Instituto de Química, Universidade de Brasília (IQ-UnB), 70904-970 Brasilia, DF (Brazil); Bezerra da Costa, Nivan; Oliveira Freire, Ricardo [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Chojnacki, Jarosław [Department of Inorganic Chemistry, Gdansk University of Technology, 80-233 Gdansk (Poland); Alves Júnior, Severino, E-mail: [Laboratório de Terras Raras, Departamento de Química Fundamental, Universidade Federal de Pernambuco (DQF-UFPE), 50590-470 Recife, PE (Brazil)


    The organic ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P2{sub 1}/c monoclinic system as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric analysis. Two new coordination networks based on lanthanide ions were obtained with this ligand using hydrothermal reaction. In addition to single-crystal X-ray diffraction, the compounds were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis. Single-crystal XRD showed that the compounds are isostructural, crystallizing in P2{sub 1}/n monoclinic system with chemical formula [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+}(1) and Eu{sup 3+}(2)).The luminescence properties of both compounds were studied. In the compound (1), a broad emission band was observed at 479 nm, redshifted by 70 nm in comparison of the free ligand. In (2), the typical f–f transition was observed with a maximum peak at 618 nm, related with the red emission of the europium ions. Computational methods were performed to simulate the crystal structure of (2). The theoretical calculations of the intensity parameters are in good agreement with the experimental values. - Graphical abstract: Scheme of obtaining the ligand 2,5-piperazinedione-1,4-diacetic acid (H{sub 2}PDA) and two new isostructural 3D-coordination polymers [Ln(PDA){sub 1.5}(H{sub 2}O)](H{sub 2}O){sub 3} (Ln=Gd{sup 3+} and Eu{sup 3+}) by hydrothermal synthesis. Display Omitted - Highlights: • The ligand 2,5-piperazinedione-1,4-diacetic acid was synthetized using the hydrothermic method and characterized. • Two new 3D-coordination polymers with this ligand containing Gd{sup 3+} and Eu{sup 3+} ions

  5. CaCl2对越冬期一品红观赏及生理特性的影响%Effects of CaCl2 on the Ornamental and Physiological Characteristics of Euphorbia pulcherrima during the Overwintering Period



    [目的]研究CaCl2对一品红抗冷性指标的影响.[方法]采用土壤浇灌的方式,设3个浓度梯度,测定并分析相关指标.[结果]土壤浇灌CaCl2可以增加低温期间一品红叶片叶绿素、可溶性糖、游离脯氨酸含量,降低自由水含量/束缚水含量比值,提高过氧化氢酶活性.[结论] CaCl2可以提高一品红耐冷性,试验以1 000mg/L浓度较好.

  6. CaCl2对高炉内碱金属富集和焦炭热态性能的影响%Influence of CaCl2 on Enrichment of Basic Metal inside Blast Furance and Coke Thermal Characteristics

    王再义; 王相力; 刘德军; 张伟; 张宁; 郝博



  7. Prediction of the density of molten MgCl2-KCl-CaCl2 ternary at 1 090 K%1090 K下MgCl2-KCl-CaCl2三元熔盐体系的密度预测

    赵飞; 陈志远; 陈洪智; 赵世强


    Electrolyte used for magnesium production should be maintained in a proper range of densities. MgCl2-KCl-CaCl2 ternary is one of the important basal melts of the electrolyte. The new generational geometric model is employed to predict the density of the ternary at the temperature of 1 090 K. Before the prediction , the density functions of molten MgCl2-CaCl2 binary to temperature are revised based on the data of NSRDS. The excess density functions of KCl-CaCl2,MgCl2-CaCl2,KCl-MgCl2 are fitted with Redlich-Kister equation. And the similarity coefficients of the three components in the ternary are worked out. The calculation results of the model are compared with the known experimental data. The relative errors of the predicted data are in the range of 2.21%~0.99%. Therefore, it is proposed that the prediction results are reliable.%镁电解工艺中使用的电解质需要具有合适的密度范围.MgCl2-KCl-CaCl2三元熔盐体系是镁电解质的重要基础三元系.使用了新一代溶液几何模型,预测了这一三元系在1090 K下的密度.首先勘正了标准数据库中的 MgCl2-CaCl2熔盐二元系的密度表达式.对已知3个二元系KCl-CaCl2、MgCl2-CaCl2、KCl-MgCl2数据,采用三次式表达的Redlich-Kister关系式拟合得到了它们的超额密度函数.并计算各组分之间的相似系数.最终获得全组分范围内的三元熔盐体系密度分布图.已知成分点的实验值与预测值之间相对误差在2.21%~0.99%之间,这表明了预测结果的可靠性.

  8. A reactant-coordinate-based approach to state-to-state differential cross sections for tetratomic reactions

    Zhao, Bin; Sun, Zhigang; Guo, Hua


    A new algorithm is proposed to compute quantum mechanically state-to-state differential cross sections for reactions involving four atoms in full dimensionality. This algorithm, which is based on the propagation of an initial state specific wave packet exclusively in reactant coordinates, extracts the S-matrix elements in the product channel by first interpolating the time-dependent wave packet using a collocation method at selected time intervals on the product coordinate grid and then projecting out the contributions of all final product states. This approach is efficient and accurate, particularly for reactions that are dominated by a product well or long-range interactions. Validation of this approach is demonstrated for the H2 + OH → H + H2O reaction.

  9. Change in organic molecule adhesion on α-alumina (Sapphire) with change in NaCl and CaCl2 solution salinity

    Juhl, Klaus; Bovet, Nicolas Emile; Hassenkam, Tue


    that the tips adhere to alumina through hydrogen bonding when only water is present. In solutions containing NaCl and CaCl2, cations are adsorbed but Cl- is not. When NaCl solutions are replaced by CaCl2, Ca2+ replaces Na+, but rinsing with ultrapure deionized water (pH 5.6) could not restore the original......We investigated the adhesion of two functional groups to α-alumina as a model for the adsorption of organic molecules on clay minerals. Interactions between organic compounds and clay minerals play an important role in processes such as drinking water treatment, remediation of contaminated soil......, oil recovery, and fabricating complicated nanomaterials, and there have been claims that organic compound-clay mineral interaction created the ordering that is necessary for the genesis of life. In many organisms, interaction between organic molecules and biominerals makes it possible to control...

  10. Temperature-induced structural changes in CaCl2 , CaBr2 , and CrCl2 : A synchrotron x-ray powder diffraction study

    Howard, Christopher J.; Kennedy, Brendan J.; Curfs, Caroline


    The halides CaCl2,CaBr2 , and CrCl2 all adopt, at room temperature, the same distorted rutile structure, in orthorhombic space group Pnnm , known as the calcium chloride structure. Upon heating, CaCl2 and CaBr2 each undergoes a continuous transformation to the true tetragonal rutile structure, in space group P42/mnm , the transition temperatures being 235 and 553 °C, respectively. By contrast, the structural change in CrCl2 upon heating is just further elongation of octahedra already lengthened by Jahn-Teller effects, and no phase transition occurs. The orthorhombic structure is maintained by a strong and temperature-dependent geometrical coupling of the orthorhombic strain to the order parameter, represented by the tilt angle of the CrCl6 octahedron.

  11. Formation of Si nanowires by the electrochemical reduction of porous Ni/SiO2 blocks in molten CaCl2

    Fang, Sheng; Wang, Han; Yang, Juanyu; Lu, Shigang; Yu, Bing; Wang, Jiantao; Zhao, Chunrong


    Silicon nanowires (SiNWs) were prepared by the electrochemical reduction of solid Ni/SiO2 blocks in molten CaCl2 at 1173 K. The SiNWs have diameter distributions ranging from 80 to 350 nm, and the nickel-silicon droplets are found on the tips of the nanowires. The growth mechanism of SiNWs was investigated, which confirmed that the nano-sized nickel-silicon droplets formed at the Ni/SiO2/CaCl2 three-phase interline. The droplets lead to the oriented growth of SiNWs. Formation of nano-sized nickel-silicon droplets suggests that this method could be a potential way to produce nano-sized metal silicides.

  12. Composite desiccant material "CaCl2/Vermiculite/Saw wood": a new material for fresh water production from atmospheric air

    Kumar, Manoj; Yadav, Avadhesh


    In this study a novel composite desiccant material "CaCl2/Vermiculite/Saw wood" have been synthesized and tested for the water generation from atmospheric air. The vermiculite- saw wood used as a host matrix and CaCl2 as a hygroscopic salt. A solar glass desiccant box type system with a collector area of 0.36 m2 has been used. Design parameters for water generation are height of glass from the desiccant material bed as 0.22 m, inclination in angle as 30º, the effective thickness of glass as 3 mm and number of glazing as single. It has been found that the concentration of calcium chloride is the most influencing factor for fresh water generation from atmospheric air. The maximum amount of water produced by using novel composite desiccant material is 195 ml/kg/day.

  13. Qualidade de carambolas azedas cv. 'Golden Star' tratadas com CaCl2 por imersão e armazenadas sob refrigeração Quality of starfruit cv 'Golden Star' treated with CaCl2 and stored under refrigerated conditions

    Leandro Camargo Neves


    Full Text Available No presente trabalho, avaliou-se o efeito de diferentes concentrações de CaCl2 aplicadas na pós-colheita de carambolas cv. 'Golden Star, durante o armazenamento refrigerado (AR. Os frutos colhidos fisiologicamente maturos foram selecionados pela ausência de defeitos e imersos em soluções de CaCl2, em diferentes concentrações, em temperatura ambiente (22 °C por 20 minutos. Após aplicação dos tratamentos T1 - controle (0% de CaCl2; T2 - CaCl2 a 1%; T3 - CaCl2 a 2%; T4 - CaCl2 a 3%, e T5 - CaCl2 a 4%, os frutos foram colocados em câmara frigorífica, por 35 dias, a 12 ± 0,5ºC e 95 ± 3%, e mais 3 dias a 22 ± 3°C e 72 ± 5% de umidade relativa (UR. 24 horas após a colheita e a cada sete dias, amostras foram retiradas da AR, mantidas por 12 horas em condições ambiente (22 ± 3°C e 72 ± 5% UR e analisadas quanto ao teor de cálcio na polpa, perda de massa fresca, coloração da epiderme, firmeza de polpa (FP, sólidos solúveis totais (SST, acidez total titulável (ATT e a ocorrência de distúrbios fisiológicos. Ao final do experimento, foi feita uma análise sensorial. Observou-se que os frutos imersos em solução de CaCl2 a 2% apresentaram menor perda de massa fresca e maior firmeza de polpa. As carambolas deste tratamento também não apresentaram manchas e podridões e foram preferidas pelos julgadores no teste de preferência. Os sólidos solúveis totais, a acidez total titulável e a coloração não apresentaram diferença estatística entre os tratamentos. Na análise de teores de cálcio adsorvido pelos frutos, determinou-se que quanto, maior a concentração da solução de CaCl2 aplicada, maior a concentração de cálcio presente na polpa.In the present work were evaluated the effects of different CaCl2 concentrations applied after harvest on starfruit cv. Golden Star, during refrigerated storage (RS. The fruits were harvested at physiological maturity stage, selected free of defects and immersed for 20 minutes at

  14. Evaluation of the effect of CaCl2 and alginate concentrations and hardening time on the characteristics of Lactobacillus acidophilus loaded alginate beads using response surface analysis

    Lotfipour, Farzaneh; Mirzaeei, Shahla; Maghsoodi, Maryam


    Purpose: This article describes preparation and characterization of beads of alginate containing probiotic bacteria of Lactobacillus acidophilus DMSZ20079. Methods: Fourteen formulations using different alginate (ALG) and CaCl2 concentrations as well as hardening times were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology, encapsulation efficiency and bacterial viabilities in acid (pH 1.8, 2 hours) condition. Results: The results showed that spherical beads with narrow size distribution ranging from 1.32±0.04 to 1.70±0.07 mm were achieved with encapsulation efficiency higher than 98%. Surface response analysis revealed that alginate concentration was the important factor for the size, shape and encapsulation efficiency of prepared beads. Furthermore, survived bacteria after acid exposure in all prepared beads (63-83%) were significantly higher than those of untreated cells (39%) and enhanced by increasing alginate concentration. Surface response analysis revealed that the effect of all three factors of alginate and CaCl2 concentrations as well as hardening times were significant in acid viability, however alginate concentration played the most important role according to its regression coefficient. Conclusion: Among alginate and CaCl2 concentrations as well as hardening times, alginate concentration was the most variable in the characteristics of Alginate beads. PMID:24312773

  15. The effect of CaCl2 on growth rate, wood decay and oxalic acid accumulation in Serpula lacrymans and related brown-rot fungi

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol. A.


    The dry rot fungus, Serpula lacrymans, is one of the most destructive copper-tolerant fungi causing timber decay in buildings in temperate regions. Calcium and oxalic acid have been shown to play important roles in the mechanism of wood decay. The effect of calcium on growth and decay was evaluated...... for 12 strains of S. lacrymans and compared to five brown-rot fungi. This was done by treating copper citrate (CC)-treated Southern yellow pine (SYP) wood with a CaCl2 solution and estimating the decay rate and amount of soluble oxalic acid in an ASTM soil block test. Decay by S. lacrymans was found....... In summary, a marked decrease was observed in the decay capacity of S. lacrymans in pine treated with CC+CaCl2. The amount of soluble oxalic acid was measured in CC-treated blocks and blocks also treated with CaCl2. Of the comparative brown-rot fungi, both Antrodia vaillantii (TFFH 294) and Postia placenta...

  16. Cation coordination reactions on nanocrystals: surface/interface, doping control and advanced photocatalysis applications (Conference Presentation)

    Zhang, Jiatao


    Abstract: Including the shape and size effect, the controllable doping, hetero-composite and surface/interface are the prerequisite of colloidal nanocrystals for exploring their optoelectronic properties, such as fluorescence, plasmon-exciton coupling, efficient electron/hole separation, and enhanced photocatalysis applications. By controlling soft acid-base coordination reactions between cation molecular complexes and colloidal nanocrystals, we showed that chemical thermodynamics could drive nanoscale monocrystalline growth of the semiconductor shell on metal nano-substrates and the substitutional heterovalent doping in semiconductor nanocrystals. We have demonstrated evolution of relative position of Au and II-VI semiconductor in Au-Semi from symmetric to asymmetric configuration, different phosphines initiated morphology engineering, oriented attachment of quantum dots into micrometer nanosheets with synergistic control of surface/interface and doing, which can further lead to fine tuning of plasmon-exciton coupling. Therefore, different hydrogen photocatalytic performance, Plasmon enhanced photocatalysis properties have been achieved further which lead to the fine tuning of plasmon-exciton coupling. Substitutional heterovalent doping here enables the tailoring of optical, electronic properties and photocatalysis applications of semiconductor nanocrystals because of electronic impurities (p-, n-type doping) control. References: (1) J. Gui, J. Zhang*, et al. Angew. Chem. Int. Ed. 2015, 54, 3683. (2) Q. Zhao, J. Zhang*, etc., Adv. Mater. 2014, 26, 1387. (3) J. Liu, Q. Zhao, S. G. Wang*, J. Zhang*, etc., Adv. Mater. 2015, 27-2753-2761. (4) H. Qian, J. Zhang*, etc., NPG Asia Mater. (2015) 7, e152. (5) M. Ji, M. Xu, etc., J. Zhang*, Adv. Mater. 2016, in proof. (6) S. Yu, J. T. Zhang, Y. Tang, M. Ouyang*, Nano Lett. 2015, 15, 6282-6288. (7) J. Zhang, Y. Tang, K. Lee and M. Ouyang*, Science 2010, 327, 1634. (8) J. Zhang, Y. Tang, K. Lee, M. Ouyang*, Nature 2010, 466

  17. Major Reaction Coordinates Linking Transient Amyloid-β Oligomers to Fibrils Measured at Atomic Level.

    Chandra, Bappaditya; Bhowmik, Debanjan; Maity, Barun Kumar; Mote, Kaustubh R; Dhara, Debabrata; Venkatramani, Ravindra; Maiti, Sudipta; Madhu, Perunthiruthy K


    The structural underpinnings for the higher toxicity of the oligomeric intermediates of amyloidogenic peptides, compared to the mature fibrils, remain unknown at present. The transient nature and heterogeneity of the oligomers make it difficult to follow their structure. Here, using vibrational and solid-state nuclear magnetic resonance spectroscopy, and molecular dynamics simulations, we show that freely aggregating Aβ40 oligomers in physiological solutions have an intramolecular antiparallel configuration that is distinct from the intermolecular parallel β-sheet structure observed in mature fibrils. The intramolecular hydrogen-bonding network flips nearly 90°, and the two β-strands of each monomeric unit move apart, to give rise to the well-known intermolecular in-register parallel β-sheet structure in the mature fibrils. Solid-state nuclear magnetic resonance distance measurements capture the interstrand separation within monomer units during the transition from the oligomer to the fibril form. We further find that the D23-K28 salt-bridge, a major feature of the Aβ40 fibrils and a focal point of mutations linked to early onset Alzheimer's disease, is not detectable in the small oligomers. Molecular dynamics simulations capture the correlation between changes in the D23-K28 distance and the flipping of the monomer secondary structure between antiparallel and parallel β-sheet architectures. Overall, we propose interstrand separation and salt-bridge formation as key reaction coordinates describing the structural transition of the small Aβ40 oligomers to fibrils. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  18. CaCl2在甘氨酸+水和丙氨酸+水混合溶剂中的活度系数%Activity Coefficients of CaCl2 in Glycine+Water and Alanine+Water Mixtures at 298.15 K

    张心宽; 卓克垒; 马晶晶; 刘宏勋; 王键吉


    利用离子选择性电极(ISE)测定了298.15 K时CaCl2在甘氨酸+水和丙氨酸+水混合溶剂中的活度系数. CaCl2的质量摩尔浓度变化范围为0.01~0.20 mol/kg, 氨基酸的质量摩尔浓度变化范围为0.10~0.40 mol/kg. 用Debye-Hückel扩展方程和Pitzer方程进行理论计算得到的活度系数基本一致. 依据McMillan-Mayer理论, 计算了CaCl2从纯水到氨基酸水溶液的标准转移Gibbs自由能, 利用最小二乘法拟合求得了对相互作用参数(gEA)和盐效应常数(ks). 讨论了这两种氨基酸的加入对CaCl2的活度系数、热力学稳定性及盐效应常数的影响.

  19. CeCl3-CaCl2-MgCl2三元体系相图的研究%Investigation on Phase Diagram of CeCl3-CaCl2-MgCl2 Ternary System

    郑朝贵; 叶于浦; 张晓励; 乔芝郁


    @@至今只见到某些稀土氯化物二元相图的报道,而含稀土的三元熔盐体系相图则研究甚少。据报道,CeCl3-CaCl2-MgCl2体系中相关的三个二元体系均属简单低共熔型。曾重新考察并测定其低共熔点的组成与温度为:CeCl3-MgCl2,54.0wt.%CeCl3(660℃)[1];CeCl3-CaCl2,57.0wt.%CeCl 3(622℃)[2];CaCl2-MgCl2,45.2wt.%MgCl2(609℃)[3]。作为系列研究含稀土氯化物三元相图与探讨其规律[4]的工作之一,本文测定了CeCl 3-CaCl2-MgCl2三元相图。 一、实验方法 MgCl2、CeCl 3和CaCl2分别由MgCl2·6H2O、CeCl3·6H2O和CaCl2·nH2O在干燥的HCl气氛中,逐级充分脱水制得[5]。除CeCl3纯度>99.5%外,其他试剂均为分析纯o CaCl2、MgCl2和CeCl3的熔点分别为:775、713和810℃。 准确配制约150mg样品,在充分干燥气氛中装入石英安瓿,抽空封口后,熔化样品并仔细摇匀,在400℃保温4h,留待差热分析。

  20. Studying the role of protein dynamics in an SN2 enzyme reaction using free-energy surfaces and solvent coordinates

    García-Meseguer, Rafael; Martí, Sergio; Ruiz-Pernía, J. Javier; Moliner, Vicent; Tuñón, Iñaki


    Conformational changes are known to be able to drive an enzyme through its catalytic cycle, allowing, for example, substrate binding or product release. However, the influence of protein motions on the chemical step is a controversial issue. One proposal is that the simple equilibrium fluctuations incorporated into transition-state theory are insufficient to account for the catalytic effect of enzymes and that protein motions should be treated dynamically. Here, we propose the use of free-energy surfaces, obtained as a function of both a chemical coordinate and an environmental coordinate, as an efficient way to elucidate the role of protein structure and motions during the reaction. We show that the structure of the protein provides an adequate environment for the progress of the reaction, although a certain degree of flexibility is needed to attain the full catalytic effect. However, these motions do not introduce significant dynamical corrections to the rate constant and can be described as equilibrium fluctuations.

  1. Energetics, transition states, and intrinsic reaction coordinates for reactions associated with O(3P) processing of hydrocarbon materials

    Yan, Tianying; Hase, William L.; Doubleday, Charles


    Electronic structure calculations based on multiconfiguration wave functions are used to investigate a set of archetypal reactions relevant to O(3P) processing of hydrocarbon molecules and surfaces. These include O(3P) reactions with methane and ethane to give OH plus methyl or ethyl radicals, O(3P)+ethane to give CH3O+CH3, and secondary reactions of the OH product radical with ethane and the ethyl radical. Geometry optimization is carried out with CASSCF/cc-pVTZ for all reactions, and with CASPT2/cc-pVTZ for O(3P)+methane/ethane. Single-point energy corrections are applied with CASPT2, CASPT3, and MRCI+Q with the cc-pVTZ and cc-pVQZ basis sets, and the energies extrapolated to the complete basis set limit (CBL). Where comparison of computed barriers and energies of reaction with experiment is possible, the agreement is good to excellent. The best agreement (within experimental error) is found for MRCI+Q/CBL applied to O(3P)+methane. For the other reactions, CASPT2/CBL and MRCI+Q/CBL predictions differ from experiment by 1-5 kcal/mol for 0 K enthalpies of reaction, and are within 1 kcal/mol of the best-estimate experimental range of 0 K barriers for O(3P)+ethane and OH+ethane. The accuracy of MRCI+Q/CBL is limited mainly by the quality of the active space. CASPT2/CBL barriers are consistently lower than MRCI+Q/CBL barriers with identical reference spaces.

  2. Effect of Calcium Chloride on Tenderness and WHC of Mutton%CaCl2处理对羊肉嫩度和系水力的影响

    丛玉艳; 朱玉博; 张建勋


    选用宰后8h的羊背最长肌,注射占肉质量3%的浓度分别为0、150、200和250 mmol/L的CaCl2溶液,将样品放在4℃左右冷藏24 h后,测定其剪切力和煮熟率,以此分析不同浓度CaCl2处理对羊肉嫩度和系水力的影响.研究结果显示,CaCl2处理能显著降低羊肉的剪切力(P0.05).注射CaCl2在改善羊肉嫩度同时,不影响羊肉的系水力.

  3. Electrochemical formation of Mg-Li-Ca alloys by codeposition of Mg, Li and Ca from LiCl-KCl-MgCl2-CaCl2 melts.

    Yan, Yong De; Zhang, Mi Lin; Xue, Yun; Han, Wei; Cao, Dian Xue; Jing, Xiao Yan; He, Li Yi; Yuan, Yi


    This work presents electrochemical formation of Mg-Li-Ca alloys via codeposition of Mg, Li and Ca on a molybdenum electrode in KCl-LiCl-MgCl(2)-CaCl(2) melts at 943 K. Cyclic voltammograms (CVs) showed that the underpotential deposition (UPD) of calcium on pre-deposited magnesium leads to the formation of a liquid Mg-Ca alloy, and the succeeding underpotential deposition of lithium on pre-deposited Mg-Ca alloy leads to the formation of a liquid Mg-Li-Ca solution. Chronopotentiometric measurements indicated that the codepositon of Mg, Li and Ca occurs at current densities more negative than -0.31 A cm(-2) in LiCl-KCl-MgCl(2) (5 wt%) melts containing 1 wt% CaCl(2). Chronoamperograms demonstrated that the onset potential for the codeposition of Mg, Li and Ca is -2.200 V, and the codeposition of Mg, Li and Ca is formed when the applied potentials are more negative than -2.200 V. X-Ray diffraction (XRD) indicated that Mg-Li-Ca alloys with different phases were formed via galvanostatic electrolysis. The microstructures of typical alpha and beta phases of Mg-Li-Ca alloys were characterized by optical microscope (OM) and scanning electron microscopy (SEM). The analysis of energy dispersive spectrometry (EDS) showed that the element Ca mainly distributes along grain boundary in Mg-Li-Ca alloys. The results of inductively coupled plasma analysis determined that the chemical compositions of Mg-Li-Ca alloys correspond with the phase structures of XRD patterns, and the lithium and calcium contents of Mg-Li-Ca alloys depend on the concentrations of MgCl(2) and CaCl(2).

  4. Resumed Activity of the Dead Sea Ca-Cl Brine and the Northward Migration of the Levant Rain System Upon the MIS5/4 Transition

    Waldmann, N.; Starinsky, A.; Stein, M.


    Terminal lakes in the arid and semi-arid region of the Dead Sea basin expanded significantly or contracted and dried up depending on the way the hydrological system is reacting to the regional and global climate during the late Pleistocene-Holocene periods. We reconstructed the precipitation and hydrological history of the drainage area of the Dead Sea basin during the transition from the last Interglacial (MIS5) to the last Glacial period (MIS4). Thus, the lakes are considered as a large rain gauges and faithful monitors of the regional hydrological-climate system. Our assessment is based on lithological, mineralogical, isotopic and chemical evidence stored in the sedimentary-limnological record of Samra (Amora) and Lisan lakes that filled the Dead Sea basin during the late Pleistocene. Deposition of CaCO3 as authigenic aragonite or calcite from the lakes depends on the relative contribution of the ancient Dead Sea Ca-Cl brine to the lake waters. During the uppermost Pleistocene time (approximately 120-80 ka) mainly authigenic calcite was deposited in the lake suggesting minor contribution of the Ca-Cl brine relative to the freshwater input. The transition from the last Interglacial to last Glacial periods (the MIS5/4 transition at approximately 70 ka) was marked by resumed activity of freshwater springs in the vicinity of the Dead Sea (depositing travertines) and enhanced activity of the Ca-Cl brines, leading to precipitation of salt and authigenic aragonite. The MIS5/4 freshwater-brine change was associated with a regional migration of rainstorms to the north of the Negev desert. Since then, during the past 70 ka rainstorms were mostly limited to the drainage area of the Jordan River and Dead Sea shoulders.

  5. Pengaruh Konsentrasi Alginat dan CaCl2 terhadap Kadar Antosianin, Aktivitas Antioksidan, dan Karakteristik Sensoris Buah Duwet (Syzygium cumini Linn Restrukturisasi (Effect of Alginate and CaCl2 Concentrations on Anthocyanin Content, Antioxidant Activity, and Sensory Characteristics of Restructured Java Plum Fruit (Syzygium cumini Linn

    Lydia Ninan Lestario


    Full Text Available Restructuration is one of the ways for processing fresh fruit without heating, so the nutritional value of fruit can be maintained. This method has been applied to several types of tropical fruits but has never been applied to java plum fruit, while it has high antioxidant activity but has a short shelf life. The aim of this research was to produce the best formulation to make restructured java plum fruit. Fresh java plum fruit puree was mixed with several concentrations of calcium alginate (1 %, 2 %, 3 %, and 4 % and CaCl2 (0.75 %; 1 %. Restructured fruit products were evaluated for total anthocyanin content, antioxidant activity, texture, pH, and sensory properties. The result of this research showed that 1 % alginate and 1 % CaCl2 gave restructured java plum fruit with the highest anthocyanin content 171.61 mg/100g (DW and highest antioxidant activity 75.79 %. The overall organoleptic test with 20 panelists showed that restructured fruit with alginate 1 % and CaCl2 1 % or 0.75 % resulted the highest score 3.75.   ABSTRAK Restrukturisasi merupakan salah satu cara pengolahan buah segar tanpa pemanasan sehingga nilai gizi buah dapat dipertahankan. Metode ini sudah diteliti pada beberapa jenis buah tropis tetapi belum pernah dilakukan terhadap buah duwet, padahal buah duwet memiliki aktivitas antioksidan tinggi tetapi memiliki daya simpan rendah. Penelitian ini bertujuan untuk menentukan formulasi terbaik pada pembuatan restrukturisasi buah duwet. Bubur buah duwet segar dicampur dengan berbagai konsentrasi alginat (1 %, 2 %, 3 %, dan 4 % dan CaCl2 (0,75 %; 1 %. Produk buah hasil restrukturisasi diukur kandungan antosianin total, aktivitas antioksidan, tekstur, pH, dan sifat-sifat sensorisnya. Hasil penelitian menunjukkan bahwa alginat 1% dan CaCl2 1% memiliki kandungan antosianin tertinggi yaitu 171,61 mg/100g (BK dan aktivitas antioksidan tertinggi yaitu 75,79 %. Uji organoleptik dengan 20 panelis menunjukkan bahwa produk restrukturisasi buah

  6. Evaluating smooth muscle cells from CaCl2-induced rat aortal expansions as a surrogate culture model for study of elastogenic induction of human aneurysmal cells.

    Gacchina, Carmen; Brothers, Thomas; Ramamurthi, Anand


    Regression of abdominal aortic aneurysms (AAAs) via regeneration of new elastic matrix is constrained by poor elastin synthesis by adult vascular cells and absence of methods to stimulate the same. We recently showed hyaluronan oligomers (HA-o) and TGF-β1 (termed elastogenic factors) to enhance elastin synthesis and matrix formation by healthy rat aortic smooth muscle cells (RASMCs). We also determined that these factors could likewise elastogenically induce aneurysmal RASMCs isolated from periadventitial CaCl(2)-injury induced rat AAAs (aRASMCs). However, the factor doses should be increased for these diseased cell types, as even when induced, elastic matrix amounts are roughly one order of magnitude lower than those produced by healthy RASMCs. We presently investigate the dose-specific elastogenic effects of HA-o (0-20  μg/mL) and TGF-β1 (0-10  ng/mL) factors on aRASMCs and compare their phenotype and elastogenic responses to those of human AAA-derived SMCs (aHASMCs); we seek to determine whether aRASMCs are appropriate surrogate cell types to study in the context of inducing elastic matrix regeneration within human AAAs. The periadventitial CaCl(2)-injury model of AAAs exhibits many of the pathological characteristics of human AAAs, including similarities in terms of decreased SMC contractile activity, enhanced proliferation, and reduced elastogenic capacity of aneurysmal SMCs (relative to healthy SMCs) when isolated and expanded in culture. Both aRASMCs and aHASMCs can be elastogenically stimulated by HA-o and TGF-β1 and show broadly similar trends in their dose-specific responses to these factors. However, compared with aHASMCs, aRASMCs appear to be far less elastogenically inducible. This may be due to differences in maturity of the AAAs studied, with the CaCl(2)-injury induced aortal expansion barely qualifying as an aneurysm and the human AAA representing a more well-developed condition. Further study of SMCs from stage-matched CaCl(2)-injury

  7. CaCl_2溶液能否鉴别Na_2CO_3溶液与NaHCO_3溶液的实验探究

    邵心阳; 肖禹; 曾冬冬



  8. Evidence of click and coordination reactions on a self-assembled monolayer by synchrotron radiation based XPS and NEXAFS

    Darlatt, Erik [BAM - Bundesanstalt fuer Materialforschung und -pruefung, 12200 Berlin (Germany); Traulsen, Christoph H.-H.; Poppenberg, Johannes; Richter, Sebastian [Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, Takustrasse 3, 14195 Berlin (Germany); Kuehn, Julius [BAM - Bundesanstalt fuer Materialforschung und -pruefung, 12200 Berlin (Germany); Schalley, Christoph A., E-mail: [Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, Takustrasse 3, 14195 Berlin (Germany); Unger, Wolfgang E.S., E-mail: [BAM - Bundesanstalt fuer Materialforschung und -pruefung, 12200 Berlin (Germany)


    Highlights: Black-Right-Pointing-Pointer Ethynyl terpyridines were clicked to azide-terminated SAMs on gold. Black-Right-Pointing-Pointer Azides and clicked terpyridines were characterized by N and C K-NEXAFS and N 1s XPS. Black-Right-Pointing-Pointer S 1s + S 2p XPS was used to characterize the buried gold-sulfur interface of the SAM. Black-Right-Pointing-Pointer Higher click reaction temperature leads to an increased amount of terpyridyl groups. Black-Right-Pointing-Pointer Introduced terpyridyl groups are accessible for Pd(II) ion coordination. - Abstract: An ethynylterpyridine was 'clicked' to an azide-terminated self-assembled monolayer on gold and characterized by synchrotron radiation based surface analysis as NEXAFS and XPS. The detection of azide and terpyridine signatures confirmed a partial click reaction at room temperature. The absence of the azides after reaction at 50 Degree-Sign C indicates an almost complete conversion. For the latter case successful Pd(II) coordination has been proven. The Au-S interface of the SAMs has been characterized by S 1s and S 2p XPS.

  9. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2)

    Bourg, I.C.; Sposito, G.


    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl{sup 2} electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO{sub 2} or high-level radioactive waste (0.34-1.83 mol{sub c} dm{sup -3}). Our results confirm the existence of three distinct ion adsorption planes (0-, {beta}-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the {beta}- and d-planes are independent of ionic strength or ion type and (2) 'indifferent electrolyte' ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl{sup +} ion pairs. Therefore, at concentrations 0.34 mol{sub c} dm{sup -3}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid 'ice-like' structures for water on clay mineral surfaces.

  10. Pore structure of new composite adsorbent SiO2·xH2O·yCaCl2 with high uptake of water from air

    刘业凤; 王如竹


    A new composite adsorbent SiO2@xH2O@yCaCl2 which is composed of macro-porous silica gel and calcium chloride is introduced. In order to analyze its adsorption theory, adsorption and desorption isotherms, BET surface areas, pore volumes and average pore diameters of macro-porous silica gel and four composite adsorbent samples with different CaCl2 content are measured using SEM and Asap2010 apparatus. From the adsorption isotherms, desorption isotherms and lag loops, it can be deduced that the main pore structure in macro-porous silica gel and the new composite adsorbent have two shapes: taper with one top open and taper or hyperbolic taper with both ends open. Based on the analysis of pore diameter distribution and lag loop, a sketch map showing calcium chloride filled in pore of macro-porous silica gel is presented. The adsorption isotherms at 25℃ are measured. Experimental results show that the new composite adsorbent can adsorb more water than common adsorbents (macro-porous silica gel, micro-porous silica gel and synthetic zeolite 13X). In the light of the results of pore structure, adsorption isotherms and lyolysis phenomenon are analyzed.

  11. Preparation of Ferrotitanium from Ilmenite by Electrolysis-Assisted Calciothermic Reduction in CaCl2-NaCl Molten Salt

    Zhou, Zhongren; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Gong, Kai; Ru, Juanjian; Xiong, Li


    Electrolysis-assisted calciothermic reduction method is proposed and successfully used to prepare ferrotitanium alloy from ilmenite by using equal-molar CaCl2-NaCl molten salt as electrolyte, molybdenum rod as cathode, and graphite as anode at 973 K with cell voltages of 3.2-4.4 V under inert atmosphere. Thermodynamics analysis of the process is presented, and the products obtained are examined with x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. It is demonstrated that the calciothermic reduction of ilmenite is a stepwise process since intermediate CaTiO3 is observed in the products partially reduced. In the calciothermic reduction process, the reduction of FeTiO3 first gives rise to the formation of Fe and CaTiO3, which as intermediates will further react with calcium metal to form ferrotitanium alloys. This is in good agreement with the prediction of thermodynamics. Experimental results also show that increasing cell voltage can accelerate the formation of calcium metal through electrolysis of CaO and CaCl2 and, hence, promote the calciothermic reduction of ilmenite. As the electrolytic zone and reduction zone are combined in the same bath, the theoretical energy requirement for the production of FeTi in the calciothermic process is lower than that in the aluminothermic process.

  12. IAEA coordinated research project on nuclear data for charged-particle monitor reactions and medical isotope production

    Capote, Roberto; Nichols, Alan L.; Nortier, Francois Meiring; Carlson, Brett V.; Engle, Jonathan W.; Hermanne, Alex; Hussain, Mazhar; Ignatyuk, Anatoly V.; Kellett, Mark A.; Kibédi, Tibor; Kim, Guinyun; Kondev, Filip G.; Lebeda, Ondrej; Luca, Aurelian; Naik, Haladhara; Nagai, Yasuki; Spahn, Ingo; Suryanarayana, Saraswatula V.; Tárkányi, Ferenc T.; Verpelli, Marco


    An IAEA coordinated research project was launched in December 2012 to establish and improve the nuclear data required to characterise charged-particle monitor reactions and extend data for medical radionuclide production. An international team was assembled to undertake work addressing the requirements for more accurate cross-section data over a wide range of targets and projectiles, undertaken in conjunction with a limited number of measurements and more extensive evaluations of the decay data of specific radionuclides. These studies are nearing completion, and are briefly described below.

  13. Effects of organic matter, CaCl2 and MgCl2 on flocculation and settling of fine sediment. CHEN Hong-song,%有机质、CaCl2和MgCl2对细颗粒泥沙絮凝沉降的影响

    陈洪松; 邵明安



  14. Homochiral coordination polymers constructed from aminocarboxylate derivates: Effect of bipyridine on the amidation reaction

    Chen Jianshan; Sheng Tianlu; Hu Shengmin; Xiang Shengchang; Fu Ruibiao; Zhu Qilong [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Wu Xintao, E-mail: [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)


    Using aminocarboxylate derivates (S)-N-(4-cyanobenzoic)-glutamic acid (denoted as cbg, 1a) and (S)-N-(4-nitrobenzoic)-glutamic acid (denoted as nbg, 1b) as chiral ligands, five new homochiral coordination polymers formulated as [Cu(cbg)(H{sub 2}O){sub 2}]{sub n} (3), [Cu(cbop){sub 2}(4,4 Prime -bipy)(H{sub 2}O)]{sub n} (4) (cbop=(S)-N-(4-cyanobenzoic)-5-oxoproline, 4,4 Prime -bipy=4,4 Prime -bipyridine), {l_brace}[Cu(nbop){sub 2}(4,4 Prime -bipy)]{center_dot}4H{sub 2}O{r_brace}{sub n} (5) (nbop=(S)-N-(4-nitrobenzoic)-5-oxoproline), {l_brace}[Cd(nbop){sub 2}(4,4 Prime -bipy)]{center_dot}2H{sub 2}O{r_brace}{sub n} (6), and [Ni(nbop){sub 2}(4,4 Prime -bipy)(H{sub 2}O){sub 2}]{sub n} (7) have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction study reveals that the original chirality of aminocarboxylate derivates is maintained in all these complexes. Complexes 3, 4, and 7 are one-dimensional infinite chain coordination polymers, while complexes 5 and 6 possess two-dimensional network structures. In situ cyclization of 1a and 1b was taken place in the formation of complexes 4-7, which may be due to the competition of 4,4 Prime -bipyridine with chiral ligands during the coordination process. Preliminary optical behavior investigation indicates that ligands 1a, 1b, and complexes 6, 7 are nonlinear optical active. - Graphical abstract: Using aminocarboxylate derivates as chiral ligands, five new homochiral coordination polymers possessing second harmonic generation activities have been hydrothermally synthesized. Highlights: Black-Right-Pointing-Pointer Two new chiral aminocarboxylate derivates were firstly synthesized. Black-Right-Pointing-Pointer Five new homochiral metal organic complexes were obtained hydrothermally based on these ligands. Black-Right-Pointing-Pointer Intramolecular amidation was taken place on the aminocarboxylate derivates during the formation of these complexes. Black-Right-Pointing-Pointer In situ

  15. CaCl2-heat shock preparation of competent cells of three Pseudomonas strains and related transformation conditions%3种假单胞菌CaCl2法感受态细胞制备及转化条件

    赵峰; 张颖; 李慧; 史荣久; 韩斯琴


    假单胞菌因其生境和代谢类型的多样性,在污染环境修复、生物转化、生物防治等领域具有广阔的应用潜力;外源基因的导入是假单胞菌遗传改造的重要环节,而感受态细胞的制备和转化方法的建立是导入外源基因的重要方法学基础.本研究以从石油污染土壤中分离筛选的假单胞菌属的3个菌株Pseudomonas putida TS11、P.stutzeri DNB、P.mendocina JJ12为对象,通过3因素4水平正交实验设计,研究了不同CaCl2浓度、热激时间及复苏时间对不同假单胞菌感受态细胞制备及转化效率的影响.结果表明:CaCl2浓度是影响假单胞菌转化效率的最主要因素(P<0.05),且在制备感受态细胞之前用无菌蒸馏水多次洗涤菌体细胞,转化率明显提高.3种假单胞菌的CaCl2转化优化条件分别为:100 mmol·L-1 CaCl2,热激3 min,复苏1.5 h;50 mmol·L-1 CaCl2,热激6 min,复苏1.5 h;75 mmol·L-1 CaCl2,热激4.5 min,复苏0.5h.在上述转化条件下,3种假单胞菌的外源质粒转化效率均达到105个转化子·μg-1DNA水平.%Pseudomonas, due to its diversity in habitat and metabolic type, makes it have broad prospects applying in bioremediation, byconversion, and biocontrol, while the introduction of exogenous gene is the key link to genetically modified Pseudomonas.The preparation and transformation of competent cells are the important methodological basis of the introduction of exogenous gene.In this paper, three Pseudomonas strains (P.putida TS11, P.stutzeri DNB, and P.mendocina JJ12) isolated from a petroleum-contaminated soil were taken as the recipient strains, and a three-factor and four-level orthogonal experiment was conducted to investigate the effects of CaCl2 concentration, heat shock duration, and recovery duration on the preparation and transformation efficiency of the strains competent cells.The results showed that CaCl2 concentration was the most important factor affecting the transformation

  16. Predicting the reaction coordinates of millisecond light-induced conformational changes in photoactive yellow protein

    Vreede, J.; Juraszek, J.; Bolhuis, P.G.


    Understanding the dynamics of large-scale conformational changes in proteins still poses a challenge for molecular simulations. We employ transition path sampling of explicit solvent molecular dynamics trajectories to obtain atomistic insight in the reaction network of the millisecond timescale part

  17. Maduración poscosecha de la feijoa (Acca sellowiana Berg tratada con CaCl2 en tres temperaturas de almacenamiento

    Ramírez Juan Manuel


    Full Text Available

    Con la finalidad de comprobar los efectos retardantes del calcio en la maduración de los frutos de feijoa (Acca sellowiana Berg, cultivar Quimba, se realizó un estudio sobre la aplicación poscosecha, mediante inmersiones de tres soluciones distintas de cloruro de calcio (5%, 10% y 15% y un testigo. La aplicación de CaCl2 prolongó la vida de almacenamiento de los fru­tos, ya que los tratamientos permitieron a los frutos so­portar las condiciones de almacenamiento. Se observó un efecto importante en la disminución de las pérdidas de peso; los frutos tratados con el porcentaje de calcio más alto (15% presentaron las menores pérdidas de peso en cada temperatura. En las fejioas almacenadas a temperatura ambiente (18° C, se observó que la in­cidencia de enfermedades fue más pequeña en los fru­tos tratados con CaCl2. La velocidad de pérdida de la firmeza de los frutos también se vio fortalecida por la adición de calcio. Con relación a las propiedades quí­micas de los frutos, no se presentaron diferencias sig­nificativas entre los tratamientos con cloruro de calcio para cada temperatura de almacenamiento; las feijoas tratadas con CaCl presentaron niveles superiores de sólidos solubles totales, a pesar de no ser significativos estadísticamente.

  18. Efectos del pH, NaCl, CaCl2 y la temperatura sobre la fuerza de cuajo de tres coagulantes/cuajos

    Osmar Thomas Morillo Piña


    Full Text Available El cuajo y los coagulantes juegan un papel fundamental en el proceso de elaboración de queso y su actividad se ve afectada por diversos parámetros tecnológicos. En este sentido se determinó el efecto del pH, concentración de NaCl, CaCl2 y de la temperatura sobre la fuerza de cuajo de un coagulante microbiano experimental (BIOMI-13, una quimosina recombinante comercial (Maxiren® y un cuajo comercial de origen animal (BIOVEN, preparados a concentraciones de 0,05 g/mL; 0,0004 g/mL y 0,0008 g/mL, respectivamente. El efecto del pH fue evaluado en un intervalo de 5,0 a 7,5 y la concentración de NaCl y CaCl2 en la leche entre 0,02 y 0,16 M. El efecto de los iones de Na y Ca en las soluciones enzimáticas fue evaluado entre 0,04 y 0,80 M y la temperatura de incubación entre 20 y 70 ºC. Se determinó que los cambios de pH tienen un efecto inversamente proporcional sobre la actividad coagulante de la leche y la máxima actividad fue a pH 5 para los tres coagulantes evaluados. La concentración de NaCl en la leche tuvo un efecto adverso sobre la actividad coagulante, mientras que el incremento de la [CaCl2] aumentó la actividad alcanzando valores máximos a 0,04 M. La presencia iones de Na en las soluciones enzimáticas tuvo el mismo efecto observado en las pruebas de concentración de NaCl en la leche y se observó un aumento de la actividad relativa conforme se incrementó la concentración de iones de Ca en la solución. Los tres coagulantes/cuajos evaluados exhibieron la máxima fuerza de cuajo a 45 ºC y tuvieron una acción catalítica muy específica sobre la leche con una marcada dependencia a los parámetros evaluados, presentando algunas diferencias entre ellos debido posiblemente a la fuente y forma de obtención.

  19. Efectos del pH, NaCl, CaCl2 y la temperatura sobre la fuerza de cuajo de tres coagulantes/cuajos

    Osmar Thomas Morillo Piña


    Full Text Available El cuajo y los coagulantes juegan un papel fundamental en el proceso de elaboración de queso y su actividad se ve afectada por diversos parámetros tecnológicos. En este sentido se determinó el efecto del pH, concentración de NaCl, CaCl2 y de la temperatura sobre la fuerza de cuajo de un coagulante microbiano experimental (BIOMI-13, una quimosina recombinante comercial (Maxiren® y un cuajo comercial de origen animal (BIOVEN, preparados a concentraciones de 0,05 g/mL; 0,0004 g/mL y 0,0008 g/mL, respectivamente. El efecto del pH fue evaluado en un intervalo de 5,0 a 7,5 y la concentración de NaCl y CaCl2 en la leche entre 0,02 y 0,16 M. El efecto de los iones de Na y Ca en las soluciones enzimáticas fue evaluado entre 0,04 y 0,80 M y la temperatura de incubación entre 20 y 70 ºC. Se determinó que los cambios de pH tienen un efecto inversamente proporcional sobre la actividad coagulante de la leche y la máxima actividad fue a pH 5 para los tres coagulantes evaluados. La concentración de NaCl en la leche tuvo un efecto adverso sobre la actividad coagulante, mientras que el incremento de la [CaCl2] aumentó la actividad alcanzando valores máximos a 0,04 M. La presencia iones de Na en las soluciones enzimáticas tuvo el mismo efecto observado en las pruebas de concentración de NaCl en la leche y se observó un aumento de la actividad relativa conforme se incrementó la concentración de iones de Ca en la solución. Los tres coagulantes/cuajos evaluados exhibieron la máxima fuerza de cuajo a 45 ºC y tuvieron una acción catalítica muy específica sobre la leche con una marcada dependencia a los parámetros evaluados, presentando algunas diferencias entre ellos debido posiblemente a la fuente y forma de obtención.

  20. Formation of CaCO3 Particle and Conductivity of Na2CO3 and CaCl2 Solution Under Magnetic Field on Dynamic Fluid System

    Nelson Saksono


    Full Text Available Hard  water  causes  the  CaCO3  scale  formation  on  the  pipe  walls and  heat  exchanger  equipments  in  industrial  or domestic  water  processes.  A  great  number  of  experimental  researches  on  the  prevention  of the  CaCO3  precipitation process  by  magnetic  field  have  been  carried  out.  In  this  research,  Na2CO3  and  CaCl2  solutions  was  magnetized  in  the circulated  flow  condition  (dynamic  fluid  system.  The  velocity  of  fluid  and  the  circulation  time  was  modified  to examine  its influences  to  the  magnetization  process.  CaCO3  content  was measured  by  titration  method  of  EDTA complexometry.  Conductivity  test  was  conducted  to  find  out  hydrate  ion  bonding.  The  results  showed  that magnetization increased the CaCO3 formation and the optimum process reaches for 10 minutes circulation on 0.554 m/s of flow rate. Magnetic field decreases the conductivities of Na2CO3 and CaCl2  solution, hence reduced the ion hydrate bonding. These results showed that magnetization on Na2CO3 and CaCl2 ionic solution was effective in controlling the CaCO3 formation by increasing CaCO3 precipitation.

  1. On the variation of bond length during large-amplitude bending from electron diffraction: the case of CaCl 2

    Hargittai, Magdolna; Veszprémi, Tamás; Pasinzki, Tibor


    All geometrical parameters, including bond lengths, are influenced by large-amplitude vibrations. The magnitude of this effect was examined for metal dihalides performing large-amplitude bending motions, using CaCl 2 as an example. By using quantum chemical calculations it was shown that the effect of bending on the bond length is very sensitive to the choice of basis set. A dynamic electron diffraction analysis, augmented with quantum chemical calculations, revealed that the effect of bending on the bond length is of moderate magnitude within experimental error. This fact contrasts with the consequences of other motions, in particular stretching, that must always be accounted for in any meaningful comparison of experimental and computed structures.

  2. Long Term Electrochemical Behavior of Creviced and Non-Creviced Alloy 22 in CaCl2 + Ca(NO3)2 Brines at 155?C

    Rodr?guez, M A; Stuart, M L; Rebak, R B


    Alloy 22 is a nickel base alloy highly resistant to all forms of corrosion. In very aggressive conditions (e.g. hot concentrated chloride containing brines) Alloy 22 could suffer localized attack, namely pitting and crevice corrosion. Chloride ion is known to be the most detrimental aggressive agent for Alloy 22 and is able to promote crevice corrosion when tight crevices exist in hot chloride containing solutions of different concentrations. Nitrate ion is an effective inhibitor of chloride induced crevice corrosion when present in a high enough [NO{sub 3}{sup -}]/[Cl{sup -}] ratio. The occurrence of localized corrosion in a given environment is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}) that the alloy may establish in the studied environment. If E{sub corr} is equal or higher than E{sub crit}, localized corrosion may be expected. This paper discusses the evolution of E{sub corr} and corrosion rate (CR) of Alloy 22 specimens in 18 m CaCl{sub 2} + 9 m Ca(NO{sub 3}){sub 2} and 18 m CaCl{sub 2} + 0.9 m Ca(NO{sub 3}){sub 2} brines at 155 C. Two types of specimens were used, polished as-welded (ASW) creviced and non-creviced specimens and as-welded plus solution heat-treated (ASW+SHT) creviced specimens. The latter contained the black annealing oxide film on the surface. Results show that, in a few immersion days E{sub corr} reached a stable value higher than the open circuit potential of a platinum electrode in 18 m CaCl{sub 2} + 9 m Ca(NO{sub 3}){sub 2} for all specimens tested. Specimens tested in this solution did not suffer any type of localized attack. On the other hand, E{sub corr} showed oscillations of up to 600 mV in 18 m CaCl{sub 2} + 0.9 m Ca(NO{sub 3}){sub 2} during the entire immersion period. These oscillations were due to pitting corrosion development. Crevice corrosion was not observed in any testing case. Corrosion rates for specimens in the latter solution ([NO{sub 3

  3. Determination of chlorine via the CaCl molecule by high-resolution continuum source graphite furnace molecular absorption spectrometry and direct solid sample analysis.

    Guarda, Ananda; Aramendía, Maite; Andrés, Irene; García-Ruiz, Esperanza; do Nascimento, Paulo Cícero; Resano, Martín


    This work investigates the possibilities of high-resolution continuum source graphite furnace molecular absorption spectrometry for the direct determination of Cl in solid samples via the CaCl molecule and measurement of its molecular absorption. The method proposed is based on addition of 400µg Ca as molecule-forming reagent and of 20µgPd as chemical modifier, which helps to stabilize the analyte and enhances sensitivity. The molecular spectrum for CaCl offers different lines with different limits of detection and linear ranges, which permitted to analyze solid samples with different Cl contents. The lowest limit of detection (0.75ng Cl, corresponding to 0.75µgg(-1) for a typical sample mass of 1mg) could be achieved by combination of three of the most sensitive lines in the vicinity of 620.862nm, while the amplest linear range (up to 860ng Cl) was achieved by selection of the less sensitive line at 377.501nm. The method developed enabled the direct determination of Cl in solid samples using simple external calibration with aqueous standards. Good precision (5-9% RSD) and accuracy was attained in a series of certified samples of very different nature (i.e. coal, iron oxide, polyethylene, human hair, pine needles, rice flour and milk) and with very different Cl contents, ranging from about 50µgg(-1) to 1% (w/w) Cl. The method appears as particularly useful for Cl determination in samples with elevated Ca contents, for which biased results with other diatomic molecules, such as AlCl or SrCl, may be obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Negative Chronotropic and Antidysrhythmic Effects of Hydroalcoholic Extract of Lemon Balm (Melissa Officinalis L.) on CaCl2-Induced Arrhythmias in Rats.

    Akhondali, Zahra; Dianat, Mahin; Radan, Maryam


    In many cases, myocardial infarction leads to arrhythmia. Since antioxidant agents have an important protective role in heart disease, these compounds in medicinal plants are used in traditional medicine. Lemon balm extract, compared to other plants of the lamiaceae family, has been proven to have significant amounts of antioxidant compounds. The aim of this study was to assess the effect of the hydroalcoholic extract of lemon balm (Melissa officinalis L.) on CaCl2-induced arrhythmias in rats. This research is an experimental study; male adult Sprague Dawley rats that weighed 200-250 g were divided randomly into three groups, i.e., 1) control (normal saline, 1 ml/kg/day), 2) extract (100 mg/kg), and 3) extract (200 mg/kg). The normal saline and the extracts were gavaged for 14 consecutive days. After anesthesia, lead II electrocardiograms were recorded for calculating the rats' heart rates (HRs). Arrhythmia was induced by intravenous injection of CaCl2 solution (140 mg/kg), and the percentages of incidence of ventricular tachycardia (VT), ventricular fibrillation (VF), and ventricular premature beats (VPB) were recorded. The results were analyzed by using Fisher's exact test and one-way ANOVA. P-values less than 0.05 were considered as significant level. Heart rates and percentages of incidence of VPB, VT, and VF were reduced significantly in extract groups (with the highest activity at 200 mg/kg) in comparison with the control group. Melissa officinalis was considered to be an antiarrhythmic agent because it reduced the percentage of incidence of VPB, VT, and VF in the groups that received it. The results indicated that Melissa officinalis had a protective effect on the heart.

  5. Tratamiento Térmico de Leche: Influencia del pH y CaCl2 en la Elaboración de Queso Cuartirolo Thermally Treated Milk: Influence of pH and CaCl2 on Cuartirolo Cheese-Making

    Oscar A Sbodio


    Full Text Available Con el objeto de mejorar la propiedad de coagular de leche entera tratada bajo condiciones moderadas de temperatura, 10 minutos a 73 °C, se estudió el efecto del pH (6.2-6.6 y la adición de CaCl2 (200 y 600 mg L-1. El proceso de la coagulación enzimática, con la acidificación de Glucono-5-Lactona, fue medido con el método del alambre caliente. A pH 6.4 y 6.6 los coágulos obtenidos a partir de leche entera tratada, mostraron tiempos de coagulación significativamente inferiores (PThe effect of pH (6.2-6.6 and CaCl2 addition (200 - 600 mg L-1 was studied, with the objective of improving the coagulation properties of whole milk treated under mild condition of temperature, 10 min at 73 °C. The hot wire method to monitor rennet coagulation induced through acidification with Glucono-5-Lactone was employed. At pH 6.4 and 6.6 the coagulum of heated milk presented lower coagulation time (P<0.05, increased máximum voltage and time where they reach máximum voltage, and a decreased in whey separation, compared to those of coagulum produced by unheated milk. The selected conditions of pH 6.4 and CaCl2 added 400 mg L-1, used in the process of cuartirolo cheese proved to be the best condition to increase the yield in 8.9% on a dry basis, without loosing consumer's acceptance.

  6. New Benchmark Set of Transition-Metal Coordination Reactions for the Assessment of Density Functionals

    Weymuth, Thomas; Chen, Peter; Reiher, Markus


    We present the WCCR10 data set of ten ligand dissociation energies of large cationic transition metal complexes for the assessment of approximate exchange--correlation functionals. We analyze nine popular functionals, namely BP86, BP86-D3, B3LYP, B3LYP-D3, B97-D-D2, PBE, TPSS, PBE0, and TPSSh by mutual comparison and by comparison to experimental gas-phase data measured with well-known precision. The comparison of all calculated data reveals a large, system-dependent scattering of results with nonnegligible consequences for computational chemistry studies on transition metal compounds. Considering further the comparison with experiment, the non-empirical functionals PBE and TPSS turn out to be among the best functionals for our reference data set. The deviation can be lowered further by including Hartree--Fock exchange. Accordingly, PBE0 and TPSSh are the two most accurate functionals for our test set, but also these functionals exhibit deviations from experiment by up to 50 kJ/mol for individual reactions. A...

  7. Nano Si preparation by constant cell voltage electrolysis of FFC-Cambridge Process in molten CaCl2

    Ji; Zhao; Shengmei; Lu; Linyan; Hu; Can; Li


    Using FFC-Cambridge Process to prepare Si from SiO2 is a promising method to prepare nanostructured and highly pure silicon for solar cells.However,the method still has many problems unsolved and the controlling effect of the cell voltage on silicon product is not clear.Here we report in this article that nano cluster-like silicon product with purity of 99.95%has been prepared by complete conversion of raw material SiO2,quartz glass plate,using constant cell voltage electrolysis FFC-Cambridge Process.By analysis of XRD,EDS,TEM,HRTEM and ICP-AES as well as the discussion from the thermodynamics calculation,the morphology and components of the product based on the change of cell voltage are clarified.It is clear that pure silicon could be prepared at the cell voltage of 1.7 2.1 V in this reaction system.The silicon material have cluster-like structure which are made of silicon nanoparticles in 20 100 nm size.Interestingly,the cluster-like nano structure of the silicon can be tuned by the used cell voltage.The purity,yield and the energy cost of silicon product prepared at the optimized cell voltage are discussed.The purity of the silicon product could be further improved,hence this method is promising for the preparation of solar grade silicon in future.

  8. ALA和CaCl2处理对黄瓜植株初花期、结果期盐胁迫的缓解效应%The effects of ALA and CaCl2 on cucumbers during initial bloom and fruit-bearing (Cucumis sativus L.) under salt stress

    杨蕊; 邹志荣; 祁向玲


    试验以津春4号黄瓜(Cucumis sativus L.)为材料,研究了ALA(5-aminole-vulinic acid)和CaCl2两种外源物质对150 mmol/L和250 mmol/L NaCl胁迫下黄瓜植株在初花期和结果期生理生化指标的影响.结果表明,ALA的作用效果较CaCl2显著,可显著提高黄瓜叶片中可溶性蛋白合量、叶绿素b/a值,降低细胞膜透性,提高根系活力,抑制MDA产生,增加黄瓜植株对盐胁迫的抵抗能力,显著提高盐胁迫下黄瓜产量,与盐胁迫下的对照相比小区产量分别提高24.9%和52.3%.

  9. Modelling choice and reaction time during arbitrary visuomotor learning through the coordination of adaptive working memory andreinforcement learning

    Guillaume eViejo


    Full Text Available Current learning theory provides a comprehensive description of how we and other animalslearn, and places behavioral flexibility and automaticity at heart of adaptive behaviors. However, the computations supporting the interactions between goal-directed and habitual decision-making systems are still poorly understood. Previous functional magnetic resonance imaging(fMRI results suggest that the brain hosts complementary computations that may differentiallysupport goal-directed and habitual processes in the form of a dynamical interplay rather than aserial recruitment of strategies. To better elucidate the computations underlying flexible behavior, we develop a dual-system computational model which can predict both performance (i.e.,participants’ choices and modulations in reaction times during learning of a stimulus-response association task. The habitual system is modelled with a simple Q-learning algorithm (QL.For the goal-directed system, we propose a new Bayesian Working Memory (BWM modelwhich searches for information in the history of previous trials in order to minimize Shannonentropy. We propose a model for QL and BWM coordination such that the expensive memorymanipulation is under control of, among others, the level of convergence of the habitual learning.We test the ability of QL or BWM alone to explain human behavior, and compare them with theperformance of model combinations, to highlight the need for such combinations to explainbehavior. Two of the tested combination models are derived from the literature, the latter beingour new proposal. In conclusion, all subjects were better explained by model combinations, andthe majority of them by our new coordination proposal.

  10. Effect of the calcium halides, CaCl{sub 2} and CaBr{sub 2}, on hydrogen desorption in the Li–Mg–N–H system

    Bill, Rachel F. [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Reed, Daniel; Book, David [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Anderson, Paul A., E-mail: [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)


    Highlights: • H{sub 2} desorption from 2LiNH{sub 2}–MgH{sub 2}–xCaX{sub 2} (x = 0, 0.1, 0.15; X = Cl, Br) samples studied. • Addition of calcium halides reduced the desorption temperature in all samples. • Peak H{sub 2} release was around 150 °C lower in ball-milled than in hand-ground samples. • The 2LiNH{sub 2}–MgH{sub 2}–0.15CaBr{sub 2} sample showed the lowest peak desorption temperature. • CaBr{sub 2} reduced the activation energy to 78.8 kJ mol{sup −1}, 24% less than the undoped sample. - Abstract: Calcium-halide-doped lithium amide–magnesium hydride samples were prepared both by hand-grinding and ball-milling 2LiNH{sub 2}–MgH{sub 2}–xCaX{sub 2} (x = 0, 0.1, and 0.15; X = Cl or Br). The addition of calcium halides reduced the hydrogen desorption temperature in all samples. The ball-milled undoped sample (2LiNH{sub 2}–MgH{sub 2}) began to desorb hydrogen at around 125 °C and peaked at 170 °C. Hydrogen desorption from the 0.15 mol CaCl{sub 2}-containing sample began ca 30 °C lower than that of the undoped sample and peaked at 150 °C. Both the onset and peak temperatures of the CaBr{sub 2} sample (x = 0.15) were reduced by 15 °C compared to the chloride. Kissinger’s method was used to calculate the effective activation energy (E{sub a}) for the systems: E{sub a} for the 0.15 mol CaCl{sub 2}-containing sample was found to be 91.8 kJ mol{sup −1} and the value for the 0.15 mol CaBr{sub 2}-containing sample was 78.8 kJ mol{sup −1}.

  11. Electrochemical preparation of NiAl intermetallic compound from solid oxides in molten CaCl{sub 2} and its corrosion behaviors in NaCl aqueous solution

    Yin Huayi; Yu Tang; Tang Diyong; Ruan Xuefeng; Zhu Hua [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Wang Dihua, E-mail: [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)


    Highlights: Black-Right-Pointing-Pointer Stoichiometric NiAl powder was prepared by one-step electrolysis of solid NiO-NiAl{sub 2}O{sub 4} in molten CaCl{sub 2}. Black-Right-Pointing-Pointer The energy consumption was as low as 6.1 kWh (kg-NiAl){sup -1}. Black-Right-Pointing-Pointer Uniform distribution and co-reduction of Ni and Al oxide played key role for Al retaining. Black-Right-Pointing-Pointer Electrolytic NiAl powder was made into dense NiAl rod by spark plasma sintering (SPS). Black-Right-Pointing-Pointer Obtained NiAl rod was self-passivated in NaCl solution and show very high corrosion resistance. - Abstract: Nickel aluminide powders were prepared by direct electrochemical reduction of solid mixture of NiO-NiAl{sub 2}O{sub 4} (Ni:Al = 1:1 in mol) precursor in molten CaCl{sub 2} at 850 Degree-Sign C. The reduction process of the solid oxide cathode was investigated by analyzing the intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It reveals that nickel is preferentially reduced and it benefits to prevent aluminum leaving from the cathode. The products obtained at the constant cell voltage electrolysis of 3.0 V for more than 4 h were stoichiometric NiAl. The energy consumption could be as low as 6.1 kWh (kg-NiAl){sup -1} based on the applied cell voltage and the consumed electrolysis charge. Furthermore, the NiAl powders were made into a dense rod by spark plasma sintering (SPS) technique. The corrosion behaviors of the NiAl rod in 0.5 mol L{sup -1} NaCl aqueous solution at room temperature were investigated by polarization curve and ac impedance measurements. It was found that the NiAl rod had satisfactory anti-corrosion ability in the solution.

  12. Effect of pH, NaCl, CaCl2 and temperature on self-assembly of β-lactoglobulin into nanofibrils: a central composite design study.

    Loveday, S M; Wang, X L; Rao, M A; Anema, S G; Singh, H


    The ability of certain globular proteins to self-assemble into amyloid-like fibrils in vitro opens opportunities for the development of new biomaterials with unique functional properties, like highly efficient gelation and viscosity enhancement. This work explored the individual and interacting effects of pH (1 to 3), NaCl (0-100 mM), CaCl(2) (0-80 mM) and heating temperature (80 to 120 °C) on the kinetics of β-lactoglobulin self-assembly and the morphology of resulting nanofibrils. Statistically significant (p < 0.05) interactions included CaCl(2)*temperature, NaCl*pH, CaCl(2)*pH, temperature*pH and NaCl*CaCl(2). Particularly notable was the very rapid self-assembly at pH 3 and the highly nonlinear effect of pH on self-assembly kinetics. Nanofibril morphologies ranged from long and semiflexible or curled and twisted to short and irregular. There did not seem to be a link between the kinetics of fibril formation and the morphology of fibrils, except at pH 3, where self-assembly was very rapid and fibrils were short and irregular, suggesting haphazard, uncontrolled self-assembly.

  13. Analysis of the Effect of the CaCl2 Mass Fraction on the Efficiency of a Heat Pump Integrated Heat-Source Tower Using an Artificial Neural Network Model

    Xiaoqing Wei


    Full Text Available An existing idle cooling tower can be reversibly used as a heat-source tower (HST to drive a heat pump (HP in cold seasons, with calcium chloride (CaCl2 aqueous solution commonly selected as the secondary working fluid in an indirect system due to its good thermo-physical properties. This study analyzed the effect of CaCl2 mass fraction on the effectiveness (ε of a closed HST and the coefficient of performance (COP of a HP heating system using an artificial neural network (ANN technique. CaCl2 aqueous solutions with five different mass fractions, viz. 3%, 9%, 15%, 21%, and 27%, were chosen as the secondary working fluids for the HSTHP heating system. In order to collect enough measured data, extensive field tests were conducted on an experimental test rig in Changsha, China which experiences hot summer and cold winter weather. After back-propagation (BP training, the three-layer (4-9-2 ANN model with a tangent sigmoid transfer function at the hidden layer and a linear transfer function at the output layer was developed for predicting the tower effectiveness and the COP of the HP under different inlet air dry-/wet-bulb temperatures, hot water inlet temperatures and CaCl2 mass fractions. The correlation coefficient (R, mean relative error (MRE and root mean squared error (RMSE were adopted to evaluate the prediction accuracy of the ANN model. The results showed that the R, MRE, and RMSE between the training values and the experimental values of ε (COP were 0.995 (0.996, 2.09% (1.89%, and 0.005 (0.060, respectively, which indicated that the ANN model was reliable and robust in predicting the performance of the HP. The findings of this paper indicated that in order to guarantee normal operation of the system, the freezing point temperature of the CaCl2 aqueous solution should be sufficiently (3–5 K below its lowest operating temperature or lower than the normal operating temperature by about 10 K. The tower effectiveness increased with

  14. Don Juan Pond, Antarctica: Near-surface CaCl2-brine feeding Earth's most saline lake and implications for Mars

    Dickson, James L.; Head, James W.; Levy, Joseph S.; Marchant, David R.


    The discovery on Mars of recurring slope lineae (RSL), thought to represent seasonal brines, has sparked interest in analogous environments on Earth. We report on new studies of Don Juan Pond (DJP), which exists at the upper limit of ephemeral water in the McMurdo Dry Valleys (MDV) of Antarctica, and is adjacent to several steep-sloped water tracks, the closest analog for RSL. The source of DJP has been interpreted to be deep groundwater. We present time-lapse data and meteorological measurements that confirm deliquescence within the DJP watershed and show that this, together with small amounts of meltwater, are capable of generating brines that control summertime water levels. Groundwater input was not observed. In addition to providing an analog for RSL formation, CaCl2 brines and chloride deposits in basins may provide clues to the origin of ancient chloride deposits on Mars dating from the transition period from “warm/wet” to “cold/dry” climates. PMID:23378901

  15. Suppression of Cell Wall Degrading Enzymes and their Encoding Genes in Button Mushrooms (Agaricus bisporus) by CaCl2 and Citric Acid.

    Khan, Zia Ullah; Jiayin, Li; Khan, Nasir Mehmood; Mou, Wangshu; Li, Dongdong; Wang, Yansheng; Feng, Simin; Luo, Zisheng; Mao, Linchun; Ying, Tiejin


    Fresh button mushrooms (Agaricus bisporus) were harvested and treated with a solution of 1.5% CaCl2 + 0.5% citric acid and stored for 16 days at 12 °C. The effects of this treatment on firmness, weight, color, cell wall compositions (cellulose and chitin) and cell wall degrading enzymes (cel1ulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase) were investigated during post-harvest storage. The expressions of major genes (Cel1, Glu1, Chi1 and PAL1) involved in cell wall degradation during post-harvest storage were also monitored. The results revealed that the post-harvest chemical treatment maintained better firmness, weight, color and inhibited cellulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase activities. These findings showed that the down-regulation of cell wall degrading enzymes is a possible mechanism that delays the softening of button mushrooms by the application of combined chemical treatment.

  16. Long-Term Corrosion Potential Behavior of Alloy 22 in Hot 5 m CaCl2 + 5 m Ca(NO3)2 Brines

    Rodriguez, M A; Carranza, R M; Stuart, M L; Rebak, R B


    Alloy 22 is a nickel base alloy highly resistant to all forms of corrosion. In very aggressive conditions (e.g. hot concentrated chloride containing brines) Alloy 22 could suffer localized attack, namely pitting and crevice corrosion. The occurrence of localized corrosion in a given environment is governed by the values of the critical potential (E{sub crit}) for crevice corrosion and the corrosion potential (E{sub corr}) that the alloy may establish in the studied environment. If E{sub corr} is equal or higher than E{sub crit}, localized corrosion may be expected. This paper discusses the evolution of E{sub corr} of Alloy 22 specimens in 5 m CaCl{sub 2} + 5 m Ca(NO{sub 3}){sub 2} brines at 100 C and 120 C. Two types of specimens were used, polished as-welded (ASW) creviced and noncreviced specimens and as-welded plus solution heat-treated (ASW+SHT) creviced specimens. The latter contained the black annealing oxide film on the surface. Results show that, for all types of Alloy 22 specimens the E{sub corr} was higher at 120 C than at 100 C, probably because a more protective film formed at the higher temperature. Specimens with the black oxide film on the surface showed more oscillations in the potential. None of the tested specimens suffered crevice corrosion probably because of the relatively high concentration of nitrate in the electrolyte, R = [NO3]/[Cl] = 1.

  17. Textural and chemical characterization of activated carbon prepared from shell of african palm (Elaeis guineensis by chemical activation with CaCl2 and MgCl2

    Sergio Acevedo


    Full Text Available Activated carbons through chemical activation of African palm shells (Elaeis guineensis with magnesium chloride and calcium chloride solutions at different concentrations were obtained. The prepared materials were characterized textural and chemically. The results show that activated carbons with higher values of surface area and pore volume are obtained when solutions with lower concentrations of the activating agent are used. The obtained activated carbons have surface areas and pore volumes with values between 10 and 501 m2 /g and 0.01 and 0.29 cm3 /g respectively. Immersion enthalpies values of solids in water were between -14.3 and -32.8 J/g and benzene between -13.9 and -38.6 J/g. Total acidity and basicity of the activated carbons had values between 23 and 262 μmol/g 123 and 1724 μmol/g respectively. pH at the point of zero charge was also determined with values between 4.08 and 9.92 for set of activated carbons . The results show that activation with CaCl2 and MgCl2 salts produce activated carbons with pores in the range of mesopores for facilitate entry of the adsorbate into the materials.

  18. Accelerating potential of mean force calculations for lipid membrane permeation: System size, reaction coordinate, solute-solute distance, and cutoffs

    Nitschke, Naomi; Atkovska, Kalina; Hub, Jochen S.


    Molecular dynamics simulations are capable of predicting the permeability of lipid membranes for drug-like solutes, but the calculations have remained prohibitively expensive for high-throughput studies. Here, we analyze simple measures for accelerating potential of mean force (PMF) calculations of membrane permeation, namely, (i) using smaller simulation systems, (ii) simulating multiple solutes per system, and (iii) using shorter cutoffs for the Lennard-Jones interactions. We find that PMFs for membrane permeation are remarkably robust against alterations of such parameters, suggesting that accurate PMF calculations are possible at strongly reduced computational cost. In addition, we evaluated the influence of the definition of the membrane center of mass (COM), used to define the transmembrane reaction coordinate. Membrane-COM definitions based on all lipid atoms lead to artifacts due to undulations and, consequently, to PMFs dependent on membrane size. In contrast, COM definitions based on a cylinder around the solute lead to size-independent PMFs, down to systems of only 16 lipids per monolayer. In summary, compared to popular setups that simulate a single solute in a membrane of 128 lipids with a Lennard-Jones cutoff of 1.2 nm, the measures applied here yield a speedup in sampling by factor of ˜40, without reducing the accuracy of the calculated PMF.

  19. Rupturing the hemi-fission intermediate in membrane fission under tension: Reaction coordinates, kinetic pathways, and free-energy barriers.

    Zhang, Guojie; Müller, Marcus


    Membrane fission is a fundamental process in cells, involved inter alia in endocytosis, intracellular trafficking, and virus infection. Its underlying molecular mechanism, however, is only incompletely understood. Recently, experiments and computer simulation studies have revealed that dynamin-mediated membrane fission is a two-step process that proceeds via a metastable hemi-fission intermediate (or wormlike micelle) formed by dynamin's constriction. Importantly, this hemi-fission intermediate is remarkably metastable, i.e., its subsequent rupture that completes the fission process does not occur spontaneously but requires additional, external effects, e.g., dynamin's (unknown) conformational changes or membrane tension. Using simulations of a coarse-grained, implicit-solvent model of lipid membranes, we investigate the molecular mechanism of rupturing the hemi-fission intermediate, such as its pathway, the concomitant transition states, and barriers, as well as the role of membrane tension. The membrane tension is controlled by the chemical potential of the lipids, and the free-energy landscape as a function of two reaction coordinates is obtained by grand canonical Wang-Landau sampling. Our results show that, in the course of rupturing, the hemi-fission intermediate undergoes a "thinning → local pinching → rupture/fission" pathway, with a bottle-neck-shaped cylindrical micelle as a transition state. Although an increase of membrane tension facilitates the fission process by reducing the corresponding free-energy barrier, for biologically relevant tensions, the free-energy barriers still significantly exceed the thermal energy scale kBT.

  20. Nonequilibrium thermodynamics in the strong coupling and non-Markovian regime based on a reaction coordinate mapping

    Strasberg, Philipp; Schaller, Gernot; Lambert, Neill; Brandes, Tobias


    We propose a method to study the thermodynamic behaviour of small systems beyond the weak coupling and Markovian approximation, which is different in spirit from conventional approaches. The idea is to redefine the system and environment such that the effective, redefined system is again coupled weakly to Markovian residual baths and thus, allows to derive a consistent thermodynamic framework for this new system-environment partition. To achieve this goal we make use of the reaction coordinate (RC) mapping, which is a general method in the sense that it can be applied to an arbitrary (quantum or classical and even time-dependent) system coupled linearly to an arbitrary number of harmonic oscillator reservoirs. The core of the method relies on an appropriate identification of a part of the environment (the RC), which is subsequently included as a part of the system. We demonstrate the power of this concept by showing that non-Markovian effects can significantly enhance the steady state efficiency of a three-level-maser heat engine, even in the regime of weak system-bath coupling. Furthermore, we show for a single electron transistor coupled to vibrations that our method allows one to justify master equations derived in a polaron transformed reference frame.




    Full Text Available A new Ca(II coordination polymer has been obtained by reaction of Ca(ClO42·H2O with 3-amino-2-pyrazinecarboxylic acid in CH3CH2OH/H2O. It was characterized by IR, 1HNMR, thermal analysis and X-ray single crystal diffraction analysis. X-ray analysis reveals that each Ca(II center is seven-coordination with a N2O5 distorted pentagonal bipyramidal coordination environment. The Ca(II ions are linked through the O atoms of 3-amino-2-pyrazinecarboxylic acid ligands to form 1D chain structure. And then a 3D network structure is constructed by hydrogen bonds and π-π stacking. The antitumor activity of 3-amino-2-pyrazinecarboxylic acid ligand and its Ca(II coordination polymer against human intestinal adenocarcinoma HCT-8 cells, lung adenocarcinoma HCT-116 cells and human lung adenocarcinoma A549 cells line have been investigated.

  2. The effects of CaCl2 at different concentrations on meat quality parameters of swine Iongissimus dorsi during shelf life%不同氯化钙浓度对货架期猪肉眼肌肉质参数的影响

    袁涛; 吴宏忠; 徐继成; 张伟力


    本试验对猪眼肌肉样设置对照、0.2mol/L CaCl2、0.4mol/L CaCl2、0.6mol/L CaCl2、0.8mol/LCaCl2五种处理,测定了pH、贮存损失、水浴损失、拿破率、L*,a*,b*值七项指标.试验结果表明:不同浓度CaCl2处理后24小时,各组pH均有显著降低(p<0.05),并且pH随CaCl2浓度的升高而降低;经CaCl2处理后肉样的拿破率都比对照组低;各处理贮存损失比对照组高,并且处理组肉样的贮存损失值随CaCl2浓度的升高呈上升趋势;这提示了CaCl2在降低了pH的同时,降低了肉样的系水力;货架期各处理的L*,a*,b*值的表现有明显的时间特点,值得进一步关注.

  3. 氯化钙对间位聚芳砜酰胺/二甲基甲酰胺溶液的影响%The Effect of CaCl2 on the Solution Behavior of Poly(3,3"-diphenylsulfone isophthalamide)/Dimethylformamide

    余优霞; 陈晟辉; 袁峥; 陆顺兴; 王华平; 张玉梅


    通过黏度法和电导率研究了间位聚芳砜酰胺——聚间二苯砜间苯二甲酰胺(mi-PSA)在二甲基甲酰胺(DMF)/氯化钙(CaCl2)中的稀溶液行为.结果表明:mi-PSA的特性黏度强烈依赖于CaCl2质量浓度的变化,并随着CaCl2质量浓度的增大出现最大值.针对这一现象,采用黏度法研究了CaCl2在DMF中的存在形式,推测CaCl2以[(DMF)4Ca] 2+Cl2-形式存在于DMF中,Cl-与mi-PSA中酰胺基团上的氢原子相互作用,导致mi-PSA在DMF/CaCl2中产生聚电解质效应.电导率随CaCl2质量浓度变化的结果同样说明了mi-PSA在DMF/CaCl2中存在着聚电解质效应.%The dilute solution properties of poly (3,3'-diphenylsulfone isophthalamide) (mi-PSA) in DMF/ CaCl2 were studied by an Ubbeholde viscometer and a Conductivity meter. It is found that the variations of intrinsic viscosity [η] of mi-PSA depend on the CaCl2 concentration and there is a maximum in [η] as a function of CaCl2. Thus the interactions between CaCl2 and DMF were studied and it was deduced that CaCl2 could be in form of [(DMF)4Ca]2+Cl2- in DMF by an Ubbeholde viscometer. Cl- will be associated with N-H groups of the macromolecule which result in the polyelectrolyte behavior of mi-PSA. The result of conductivity as a function of CaCl2 concentration also explains that mi-PSA behaves as polyelectrolyte in DMF/CaCl2.

  4. Preparation and Reactions of the 1,1-Dithiolato Complexes of Ni(II). An Undergraduate Coordination Chemistry Experiment.

    Ballester, L.; Perpinan, M. F.


    Described is an undergraduate coordination chemistry experiment that enables students to relate concepts developed in class about the stereochemistry and coordination numbers to the interpretation of the electronic and infrared spectra and their magnetic behavior. Indicates that thermal decomposition and x-ray diffraction studies can also be…

  5. 不同温度下氯化钙-葡萄糖-水体系的活度研究%Study of Activity Coefficients for CaCl2-glucose System in Water at Different Temperature

    李小庆; 李晶


    Electrochemical cells with a calcium ion selective electrode ( Ca-ISE ) versus a chlorine ion selective electrode ( Cl-ISE) as a reference electrode were used to determine the activity coefficients for CaCl2-glucose system in water at 308. 15 K and 318. 15 K, the molality rage of glucose was from 0. 1 to 2. 0 mol · kg-1 . A comparison of the results thus obtained was made with those determined by another electromotive force ( emf) method. It was showed that agreement was excellent. At the same time, the activity coefficients for CaCl2 -glucose-water systems at these temperatures were compared with other reference data. The results suggested that the activity coefficients for CaCl2 in the systems not only related to molality but also to temperature.%用一个钙离子选择性电极( Ca-ISE )和一个氯离子选择性电极( Cl-ISE )作参比电极组成的电池测定308.15 K和318.15 K下水中CaCl2-葡萄糖体系的平均活度系数,糖的浓度从0.1~2.0 mol·kg-1,此法和用其他电动势法测得的结果一致性相当好。同时,结合参考文献的其他数据综合比较了不同温度下活度系数随浓度及温度的变化情况。结果表明,活度系数不但与浓度有关,而且也与温度有关。

  6. The role of chemical additives to the phase change process of CaCl2.6H2O to optimize its performance as latent heat energy storage system

    Sutjahja, I. M.; U, S. Rahayu A.; Kurniati, Nia; Pallitine, Ivyalentine D.; Kurnia, D.


    CaCl2.6H2O is one of salt hydrate based phase change material (PCM) which is suitable for room air-temperature stabilizer because it has the melting temperature just above the human comfort zone temperature (Tm ∼⃒ 29 oC) and a relatively large heat entalphy (AH ∼⃒ 190 kJ/kg). This paper reports the role of the type of chemical additives to PCM CaCl2.6H2O to the phase change process throughout the solidification process or heat release in order to optimize its performance as latent heat energy storage system. In this research we used several kinds of chemical additive, namely SrCl2.6H2O (1.0 wt%), BaCO3 (0.5 wt%), and K2CO3 (0.5 wt%). In terms of its latent time for phase change process the order the effectiveness of those chemical additives are reduced from SrCl2.6H2O, BaCO3and K2CO3. We found that this is also related to their role in suppression supercooling and phase separation effects which occurs during crystallization process of CaCl2.6H2O.

  7. Preparation of 45Ca(HDEHP)n and (CaH{sub 1}50{sub 2})2 samples for liquid scintillation counting, compared to 45caCl{sub 2} results; Preparacion de Ca (HDEHP)n y (C{sub 8}H{sub 1}50{sub 2})2 marcados con 45Ca y estudio comparativo con 4 5ca Cl2 en medidas por centelleo liquido

    Rodriguez, L.; Arcos, J. M. los; Grau Malonda, A.


    A procedure for preparation of liquid scintillation counting organic samples of the Di-2-ethylhexyl phosphate calcium complex and the 2-ethylhexanoate calcium salt, labelled with 45Ca, is described. The chemical quench, the counting stability and spectral evolution of both compounds is studied in six scintillators,Toluene-alcohol, Dioxane-naphtalene, Hi safe II, Ultimate-Gold and Instagel, and compared to results obtained from a commercial solution of 4 5CaCl2. (Author) 7 refs.

  8. Effects of a Lidocaine-Loaded Poloxamer/Alginate/CaCl2 Mixture on Postoperative Pain and Adhesion in a Rat Model of Incisional Pain.

    Choi, Geun Joo; Kang, Hyun; Hong, Min Eui; Shin, Hwa Yong; Baek, Chong Wha; Jung, Yong Hun; Lee, Younsuk; Kim, Jeong Wook; Park, I L Kyu; Cho, Wan Jin


    Pain and adhesion are problematic issues after surgery. Lidocaine has analgesics and anti-inflammatory properties, and poloxamer/alginate/CaCl2 (PACM) is a known antiadhesive agent. We hypothesized that the novel combination of lidocaine as chemical barrier and PACM as physical barrier would be beneficial for both postoperative pain and adhesion. The purpose of this study was to investigate the effects of lidocaine-loaded PACM in a rat model of incisional pain. Primary outcome was to evaluate between-group differences for the mechanical withdrawal threshold (MWT) measured by von Frey filament in various concentrations of lidocaine-loaded PACM applied, PACM applied, and sham-operated groups. Male Sprague-Dawley rats were used for the postoperative pain model. After plantar incision and adhesion formation, 0.5%, 1%, 2%, and 4% lidocaine-loaded PACM, PACM only, nothing, and 4% lidocaine only were applied at the incision site in groups PL0.5, PL1, PL2, PL4, P, S, and L4, respectively. MWT using a von Frey filament and serum levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and high-sensitivity C-reactive protein were measured. Rats were euthanized 2 weeks after surgery, and inflammation and fibrosis were assessed with microscopy. Data were analyzed using the Kruskal-Wallis test, multivariate analysis of variance, and linear mixed-effect model. To compare MWT at each time point, analysis of variance with Bonferroni correction was used. Multivariate analysis of variance showed that 4% lidocaine-loaded PACM significantly raised the MWT up to 6 and 8 hours after surgery compared with lidocaine-unloaded groups S and P, respectively; 2% lidocaine-loaded PACM significantly increased the MWT at 4 hours after surgery compared with groups S and C. Linear mixed-effect model showed that the MWT (estimated difference in means [95% confidence interval]) was significantly increased in groups PL2 and PL4 (6.58 [2.52-10.63], P = .002; 11.46 [7.40-15.51], P lidocaine only

  9. Communication: State-to-state dynamics of the Cl + H2O → HCl + OH reaction: Energy flow into reaction coordinate and transition-state control of product energy disposal.

    Zhao, Bin; Sun, Zhigang; Guo, Hua


    Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H2O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H2O → H2 + OH reaction. The strong enhancement of reactivity by the H2O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal.

  10. Molecule-Level g-C3N4 Coordinated Transition Metals as a New Class of Electrocatalysts for Oxygen Electrode Reactions

    Zheng, Yao


    Organometallic complexes with metal-nitrogen/carbon (M-N/C) coordination are the most important alternatives to precious metal catalysts for oxygen reduction and evolution reactions (ORR and OER) in energy conversion devices. Here, we designed and developed a range of molecule-level graphitic carbon nitride (g-C3N4) coordinated transition metals (M-C3N4) as a new generation of M-N/C catalysts for these oxygen electrode reactions. As a proof-of-concept example, we conducted theoretical evaluation and experimental validation on a cobalt-C3N4 catalyst with a desired molecular configuration, which possesses comparable electrocatalytic activity to that of precious metal benchmarks for the ORR and OER in alkaline media. The correlation of experimental and computational results confirms that this high activity originates from the precise M-N2 coordination in the g-C3N4 matrix. Moreover, the reversible ORR/OER activity trend for a wide variety of M-C3N4 complexes has been constructed to provide guidance for the molecular design of this promising class of catalysts.

  11. Methylresorcinarene: a reaction vessel to control the coordination geometry of copper(II) in pyridine N-oxide copper(II) complexes.

    Beyeh, Ngong Kodiah; Puttreddy, Rakesh


    Pyridine and 2-picolinic acid N-oxides form 2 : 2 and 2 : 1 ligand : metal (L : M) discrete L2M2 and polymeric complexes with CuCl2 and Cu(NO3)2, respectively, with copper(ii) salts. The N-oxides also form 1 : 1 host-guest complexes with methylresorcinarene. In combination, the three components form a unique 2 : 2 : 1 host-ligand-metal complex. The methylresorcinarene acts as a reaction vessel/protecting group to control the coordination of copper(ii) from cis-see-saw to trans-square planar, and from octahedral to square planar coordination geometry. These processes were studied in solution and in the solid state via(1)H NMR spectroscopy and single crystal X-ray diffraction.

  12. Investigation of coordination of Mg(II) cations to 2-pyrimidinyloxy-N-arylbenzylamines by electrospray mass spectrometry: insights for Mg(II) catalyzed Smiles rearrangement reactions.

    Wang, Haoyang; Xu, Chu; Zhang, Li; Tang, Qinghong; Guo, Yinlong; Lu, Long


    The CH(3)OH solutions of pyrimidinyloxy-N-arylbenzylamines (1-5) in the presence of Mg(II)X(2) salts (X = Cl or ClO(4)) were investigated by electrospray ionization mass spectrometry and tandem mass spectrometry (MS/MS) subsequently, showing that the cationic Mg(II) complexes 1-5·MgX(+) were important active complexes or intermediates for initiating interesting Smiles rearrangement reactions in both the gas and solution phases. By using different MgX(2) salts and selecting a set of reactants with different substitutes, the role of the counter-ion (X(-)) and the structure effect of the reactants on the Mg(II) catalyzed Smiles rearrangement reactions were studied. Moreover, the solvent effect on Mg(II) catalyzed Smiles rearrangement reactions was revealed by studying the CH(3)OH adduct complexes of 1-5·MgCl(+), which showed that the coordination of CH(3)OH to the Mg(II) center in the complexes decreased the reaction tendency. The mechanisms involved in the gas-phase Mg(II) catalyzed Smiles rearrangement reactions were proposed on the basis of MS/MS experiments and theoretical computations, showing some unique chemistries initiated by introducing Mg(II) into the template molecules.

  13. Crystal Structures Reveal that the Reaction Mechanism of Imidazoleglycerol-Phosphate Dehydratase Is Controlled by Switching Mn(II) Coordination

    Bisson, Claudine; Britton, K. Linda; Sedelnikova, Svetlana E.; Rodgers, H. Fiona; Eadsforth, Thomas C.; Viner, Russell C.; Hawkes, Tim R.; Baker, Patrick J.; Rice, David W.


    Summary Imidazoleglycerol-phosphate dehydratase (IGPD) catalyzes the Mn(II)-dependent dehydration of imidazoleglycerol phosphate (IGP) to 3-(1H-imidazol-4-yl)-2-oxopropyl dihydrogen phosphate during biosynthesis of histidine. As part of a program of herbicide design, we have determined a series of high-resolution crystal structures of an inactive mutant of IGPD2 from Arabidopsis thaliana in complex with IGP. The structures represent snapshots of the enzyme trapped at different stages of the catalytic cycle and show how substrate binding triggers a switch in the coordination state of an active site Mn(II) between six- and five-coordinate species. This switch is critical to prime the active site for catalysis, by facilitating the formation of a high-energy imidazolate intermediate. This work not only provides evidence for the molecular processes that dominate catalysis in IGPD, but also describes how the manipulation of metal coordination can be linked to discrete steps in catalysis, demonstrating one way that metalloenzymes exploit the unique properties of metal ions to diversify their chemistry. PMID:26095028

  14. Water activities of NaClO4, Ca(ClO4)2, and Mg(ClO4)2 brines from experimental heat capacities: Water activity >0.6 below 200 K

    Toner, J. D.; Catling, D. C.


    Perchlorate salts found on Mars are extremely hygroscopic and form low eutectic temperature aqueous solutions, which could allow liquid water to exist on Mars despite cold and dry conditions. The formation, dynamics, and potential habitability of perchlorate salt solutions can be broadly understood in terms of water activity. Water activity controls condensation and evaporation of water vapor in brines, deliquescence and efflorescence of crystalline salts, and ice formation during freezing. Furthermore, water activity is a basic parameter defining the habitability of aqueous solutions. Despite the importance of water activity, its value in perchlorate solutions has only been measured at 298.15 K and at the freezing point of water. To address this lack of data, we have determined water activities in NaClO4, Ca(ClO4)2, and Mg(ClO4)2 solutions using experimental heat capacities measured by Differential Scanning Calorimetry. Our results include concentrations up to near-saturation and temperatures ranging from 298.15 to 178 K. We find that water activities in NaClO4 solutions increase with decreasing temperature, by as much as 0.25 aw from 298.15 to 178 K. Consequently, aw reaches ∼0.6-0.7 even for concentrations up to 15 molal NaClO4 below 200 K. In contrast, water activities in Ca(ClO4)2 and Mg(ClO4)2 solutions generally decrease with decreasing temperature. The temperature dependence of water activity indicates that low-temperature NaClO4 solutions will evaporate and deliquesce at higher relative humidity, crystallize ice at higher temperature, and potentially be more habitable for life (at least in terms of water activity) compared to solutions at 298.15 K. The opposite effects occur in Ca(ClO4)2 and Mg(ClO4)2 solutions.

  15. Coordination Chemistry of [Co(acac)2 ] with N-Doped Graphene: Implications for Oxygen Reduction Reaction Reactivity of Organometallic Co-O4 -N Species.

    Han, Jongwoo; Sa, Young Jin; Shim, Yeonjun; Choi, Min; Park, Noejung; Joo, Sang Hoon; Park, Sungjin


    Hybridization of organometallic complexes with graphene-based materials can give rise to enhanced catalytic performance. Understanding the chemical structures within hybrid materials is of primary importance. In this work, archetypical hybrid materials are synthesized by the reaction of an organometallic complex, [Co(II) (acac)2 ] (acac=acetylacetonate), with N-doped graphene-based materials at room temperature. Experimental characterization of the hybrid materials and theoretical calculations reveal that the organometallic cobalt-containing species is coordinated to heterocyclic groups in N-doped graphene as well as to its parental acac ligands. The hybrid material shows high electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline media, and superior durability and methanol tolerance to a Pt/C catalyst. Based on the chemical structures and ORR experiments, the catalytically active species is identified as a Co-O4 -N structure.

  16. Light-induced copper(II) coordination by a bicyclic tetraaza chelator through a ligand-to-metal charge-transfer reaction.

    Holm-Jørgensen, Jacob R; Jensen, Mikael; Bjerrum, Morten J


    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values and high temperatures are applied. We have investigated the effects of the variation in the pH, different anions, and UV irradiation on the chelation rate. UV spectra of mixtures of Cu(2+) and [2(4).3(1)]adz in water show the existence of a long-lived two-coordinated copper(II) intermediate (only counting coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu(2+) and [2(4).3(1)]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation of the four-coordinated copper(II) complex at a rate up to 7800-fold higher at 25 °C than in the dark. Anions in the solution were found to have three major effects: competitive inhibition due to Cu(II) binding anions, inhibition of the photoinduced transchelation from UV-absorbing anions, and photoredox inhibition from acido ligands capable of acting as electron donors in LMCT reactions. Dissolved O(2) was also found to result in photoredox inhibition.

  17. Reaction Mechanism for Direct Proton Transfer from Carbonic Acid to a Strong Base in Aqueous Solution II: Solvent Coordinate-Dependent Reaction Path.

    Daschakraborty, Snehasis; Kiefer, Philip M; Miller, Yifat; Motro, Yair; Pines, Dina; Pines, Ehud; Hynes, James T


    The protonation of methylamine base CH3NH2 by carbonic acid H2CO3 within a hydrogen (H)-bonded complex in aqueous solution was studied via Car-Parrinello dynamics in the preceding paper (Daschakraborty, S.; Kiefer, P. M.; Miller, Y.; Motro, Y.; Pines, D.; Pines, E.; Hynes, J. T. J. Phys. Chem. B 2016, DOI: 10.1021/acs.jpcb.5b12742). Here some important further details of the reaction path are presented, with specific emphasis on the water solvent's role. The overall reaction is barrierless and very rapid, on an ∼100 fs time scale, with the proton transfer (PT) event itself being very sudden (water solvent changes little until the actual PT occurrence; this results from the very strong driving force for the reaction, as indicated by the very favorable acid-protonated base ΔpKa difference. Further solvent rearrangement follows immediately the sudden PT's production of an incipient contact ion pair, stabilizing it by establishment of equilibrium solvation. The solvent water's short time scale ∼120 fs response to the incipient ion pair formation is primarily associated with librational modes and H-bond compression of water molecules around the carboxylate anion and the protonated base. This is consistent with this stabilization involving significant increase in H-bonding of hydration shell waters to the negatively charged carboxylate group oxygens' (especially the former H2CO3 donor oxygen) and the nitrogen of the positively charged protonated base's NH3(+).

  18. Mechanical and water-holding properties and microstructures of soy protein isolate emulsion gels induced by CaCl2, glucono-δ-lactone (GDL), and transglutaminase: influence of thermal treatments before and/or after emulsification.

    Tang, Chuan-He; Chen, Ling; Foegeding, Edward Allen


    The mechanical properties, water-holding capacities (WHC), and microstructures of emulsion gels, induced by glucono-δ-lactone (GDL), CaCl(2), and microbial transglutaminase (MTGase) from unheated and heated soy protein isolate (SPI)-stabilized emulsions (at protein concentration 5%, w/v; oil volume fraction, 20%, w/v), were investigated and compared. The influence of thermal pretreatments (at 90 °C for 5 min) before and/or after emulsification was evaluated. Considerable differences in mechanical, water-holding, and microstructural properties were observed among various emulsion gels. The thermal pretreatment after emulsification increased the strength of the emulsion gels induced by GDL and CaCl(2), whereas in the case of MTGase, thermal pretreatments before and/or after emulsification on the contrary greatly inhibited gel network formation. The application of the enzyme coagulant exhibited much higher potential to form SPI-stabilized emulsion gels with higher mechanical strength than that of the other two coagulants. The WHC of the emulsion gels seemed to be not directly related to their gel network strength. Confocal laser scanning microscope analyses indicated that the network microstructure of the formed emulsion gels, mainly composed of aggregated protein-stabilized oil droplets and protein aggregate clumps, varied with the type of applied coagulants and emulsions. The differences in microstructure were basically consistent with the differences in mechanical properties of the gels. These results could provide valuable information for the formation of cold-set soy protein-stabilized emulsion gels.

  19. The effectiveness of organic PCM based on lauric acid from coconut oil and inorganic PCM based on salt hydrate CaCl2.6H2o as latent heat energy storage system in Indonesia

    U, Sri Rahayu A.; Putri, Widya A.; Sutjahja, I. M.; Kurnia, D.; Wonorahardjo, S.


    A latent heat energy storage system utilizing phase change materials (PCM) is an alternative strategy to reduce the use of Air Conditioning (AC) system in big cities in Indonesia in order for energy conservation in the future. In this research we used two kinds of materials, namely organic PCM based on lauric acid from coconut oil (CO) and inorganic PCM based on salt hydrate CaCl2.6H2O, because they have thermophysical parameters suitable for human's thermal comfort application in the building. The CO which contained more than 50% lauric acid has the melting temperature (Tm ) of about 26 °C and heat entalphy (ΔH) around 103 kJ/kg, while CaCl2.6H2O has the melting point of 29 °C and heat entalphy of 190 kJ/kg. In this paper we report the effectiveness of those two kinds of PCM in reducing the air temperature as one of some criteria for human's thermal comfort. The experiments were performed in a close and adiabatic room and the time-temperature measurements were done automatically using Arduino microcontroller and LM35 temperature sensor connected to the PC.

  20. A DFT study on the correlation between topology and Bader charges: Part IV, on the change of atomic charges in polymorphic transitions - A case study on CaCl2

    Beck, Horst P.


    Referring to the experimental results of high pressure experiments of Léger et al. (1998) we have calculated the energies of all phases observed for CaCl2 within the DFT formalism using the VASP package, and we have retrieved enthalpies and transition pressures. All phases can be considerably compressed or dilated without much change in energy. This energetic "softness" could even be quantified. We classify the high temperature TiO2-type structure and the PbCl2-type one at highest pressures as the energetically "softest" ones and the SrI2-type one as the "hardest". We furthermore discuss the energy density (E/V) of the different phases and redefine it as a fictive cohesive pressure within these structures. Pursuing our earlier approaches we have analysed the charges of the atoms in the different CaCl2 phases and their change on compression or dilation. On comparing the gradients of the charge curves we define a sort of "charge hardness" which will generally depend on the type of cation-anion pair but also on their topological connection in the respective structures. We speculate that exhausting the "charge softness or hardness" of individual ions in such arrangements may initiate the structural reorganization at the transition pressures.

  1. Influence of chlorine coordination number on the catalytic mechanism of ruthenium chloride catalysts in the acetylene hydrochlorination reaction: a DFT study.

    Han, You; Sun, Mengxia; Li, Wei; Zhang, Jinli


    The catalytic mechanism of Ru-based catalysts in the acetylene hydrochlorination reaction has been investigated via the density functional theory (DFT) method. To study the effect of the chlorine coordination number on the catalytic mechanism, Ru3Cl9, Ru3Cl7, Ru5Cl7, Ru3Cl3 and Ru3 clusters were chosen as the catalytic models. Our results show that the energy barrier for acetylene hydrochlorination on Ru3Cl9 was as high as 1.51 eV at 458 K. When the chlorine coordination number decreased, the energy barriers on Ru3Cl7, Ru5Cl7, Ru3Cl3 and Ru3 were 1.29, 0.89, 1.01 and 1.42 eV, respectively. On Ru3Cl9, the H and Cl atoms of HCl were simultaneously added to C2H2 to form C2H3Cl, while the reaction was divided into two steps on Ru3Cl7, Ru3Cl3 and Ru3 clusters. The first step was the addition of H atom of HCl to C2H2 to form C2H3˙, and the second step was the addition of Cl atom to C2H3˙ to form C2H3Cl. The step involving the addition of Cl was the rate-controlling step during the whole reaction. On Ru5Cl7 cluster, there was an additional step before the steps involving the addition of H and Cl: the transfer of H atom from HCl to Ru atom. This step was the rate-controlling step during the reaction of acetylene hydrochlorination on Ru5Cl7 and its energy barrier was the lowest among all the above-mentioned catalytic models. Therefore, the Ru5Cl7 cluster played the most predominant role in acetylene hydrochlorination with the largest reaction rate constant kTST of 10(3).

  2. Reactions of nitrogen oxides with the five-coordinate Fe(III)(porphyrin) nitrito intermediate Fe(Por)(ONO) in sublimed solids.

    Kurtikyan, Tigran S; Hovhannisyan, Astghik A; Hakobyan, Manya E; Patterson, James C; Iretskii, Alexei; Ford, Peter C


    Detailed experimental studies are described for reactions of several nitrogen oxides with iron porphyrin models for heme/NxOy systems. It is shown by FTIR and optical spectroscopy and by isotope labeling experiments that reaction of small increments of NO2 with sublimed thin layers of the iron(II) complex Fe(Por) (Por = meso-tetraphenylporphyrinato dianion, TPP, or meso-tetra-p-tolylporphyrinato dianion, TTP) leads to formation of the 5-coordinate nitrito complexes Fe(Por)(eta1-ONO) (1), which are fairly stable but very slowly decompose under vacuum giving mostly the corresponding nitrosyl complexes Fe(Por)(NO). Further reaction of 1 with new NO2 increments leads to formation of the nitrato complex Fe(Por)(eta2-O2NO) (2). The interaction of NO with 1 at low temperature involves ligand addition to give the nitrito-nitrosyl complexes Fe(Por)(eta1-ONO)(NO) (3); however, these isomerize to the nitro-nitrosyl analogs Fe(Por)(eta1-NO2)(NO) (4) upon warming. Experiments with labeled nitrogen oxides argue for an intramolecular isomerization ("flipping") mechanism rather than one involving dissociation and rebinding of NO2. The Fe(III) centers in the 6-coordinate species 3 and 4 are low spin in contrast to 1, which appears to be high-spin, although DFT computations of the porphinato models Fe(P)(nitrite) suggest that the doublet nitro species and the quartet and sextet nitrito complexes are all relatively close in energy. The nitro-nitrosyl complex 4 is stable under an NO atmosphere but decomposes under intense pumping to give a mixture of the ferrous nitrosyl complex Fe(Por)(NO) and the ferric nitrito complex Fe(Por)(eta1-ONO) indicating the competitive dissociation of NO and NO2. Hence, loss of NO from 4 is accompanied with nitro --> nitrito isomerization consistent with 1 being the more stable of the 5-coordinate NO2 complexes of iron porphyrins.

  3. Coordination polymer derived cobalt embedded in nitrogen-doped carbon nanotubes for efficient electrocatalysis of oxygen evolution reaction

    Cong, Jingkun; Li, Changqing; Zhao, Tao; Wu, Jin; Zhang, Rui; Ren, Wenjing; Wang, Shunli; Gao, Junkuo; Liu, Yi; Yao, Juming


    In this paper, we reported the fabrication of Co-embedded nitrogen-doped carbon nanotube (Co-NCNT) by using Co-melamine coordination polymer (CP) as precursor. The sample was well characterized via SEM, TEM, XRD, XPS and BET methods. The Co-NCNT shows excellent and stable catalytic performance for OER. The overpotential of Co-NCNT at 10 mA cm-2 is 370 mV (vs RHE). The current density of Co-NCNT could reach 100 mA cm-2 at overpotential of 520 mV, which showed much better performance than RuO2, while the largest current density of RuO2 could reach is only 44 mA cm-2. The Tafel slope of Co-NCNT is 56 mV dec-1, which is smaller than that of commercial RuO2 (58 mV dec-1). The results indicate that metal-melamine based CPs or MOFs can be promising precursors for the preparation of efficient metal-embedded nitrogen-doped carbon materials for electrocatalysis.

  4. L-亮氨酸与醋酸铜固相配位反应的热化学研究%Study on Thermochemistry of Solid State Coordination Reaction of L-Leucine with Copper Acetate

    周传佩; 陈文生; 刘义; 屈松生


    The reaction enthalpy of solid-solid coordination reaction of L-Leucine with copper acetate is determined by solution calorimetry in an isoperibel reaction calorimeter. The calorimetric solvent is the solution of hydrochloric acid(4 mol/L), a new thermochemical cycle is designed. The values of △fHθm=1S. 64 kJ/mol, △fHθm(trans-Cu(L-Leu)2,s)=-1194. 7 kJ/mol are evalcated.

  5. Formation of diphenylphosphanylbutadienyl complexes by insertion of two P-coordinated alkynylphosphanes into a PtbondC6F5 bond: detection of intermediate and reaction products.

    Ara, Irene; Forniés, Juan; García, Ana; Gómez, Julio; Lalinde, Elena; Moreno, M Teresa


    The reactions between cis-[M(C(6)F(5))(2)(PPh(2)CtriplebondCR)(2)] (M=Pt, Pd; R=Ph, tBu, Tol 2, 3) or cis-[Pt(C(6)F(5))(2)(PPh(2)CtriplebondCR)(PPh(2)CtriplebondCtBu)] (R=Ph 4, Tol 5) and cis-[Pt(C(6)F(5))(2)(thf)(2)] 1 have been investigated. Whereas [M](PPh(2)CtriplebondCtBu)(2) ([M]=cis-M(C(6)F(5))(2)) is inert towards 1, the analogous reactions starting from [M](PPh(2)CtriplebondCR)(2) or [Pt](PPh(2)CtriplebondCR)(PPh(2)CtriplebondCtBu) (R=Ph, Tol) afford unusual binuclear species [Pt(C(6)F(5))(S)mu-[C(R')dbondC(PPh(2))C(PPh(2))doublebondC(R)(C(6)F(5))]M(C(6)F(5))(2)] (R=R'=Ph, Tol, M=Pt 6 a,c, M=Pd 7 a,c; M=Pt, R'=tBu, R=Ph 8, Tol 9) containing a bis(diphenylphosphanyl)butadienyl bridging ligand formed by an unprecedented sequential insertion reaction of two P-coordinated PPh(2)CtriplebondCR ligands into a PtbondC(6)F(5) bond. Although in solution the presence of coordinated solvent S (S=(thf)(x)(H(2)O)(y)) in 6, 7 is suggested by NMR spectroscopy, X-ray diffraction analyses of different crystals of the mixed complex [Pt(C(6)F(5))mu-[C(tBu)doublebondC(PPh(2))C(PPh(2))doublebondC(Tol)(C(6)F(5))]Pt(C(6)F(5))(2)] 9 unequivocally establish that in the solid state the steric crowding of the new diphenylbutadienyl ligand formed stabilizes an unusual coordinatively unsaturated T-shaped 3-coordinated platinum(II) center. Structure determinations of the mononuclear precursors cis-[Pt(C(6)F(5))(2)(PPh(2)CtriplebondCR)(2)] (R=Ph, tBu, Tol) have been carried out to evaluate the factors affecting the insertion processes. The reactions of the platinum complexes 6 towards neutral ligands (L=CO, py, PPh(2)H, CNtBu) in a 1:1 molar ratio afford related diplatinum derivatives 10-13, whereas treatment with CNtBu (1:2 molar ratio) or 2,2'-bipy (1:1 molar ratio) results in the opening of the chelating ring to give cis,cis-[Pt(C(6)F(5))(L)(2)mu-[1-kappaC(1):2-kappaPP'-C(R)doublebondC(PPh(2))C(PPh(2))doublebondC(R)(C(6)F(5))]Pt(C(6)F(5))(2)] (14, 15). The unsaturated or solvento

  6. Localizing internal friction along the reaction coordinate of protein folding by combining ensemble and single-molecule fluorescence spectroscopy.

    Borgia, Alessandro; Wensley, Beth G; Soranno, Andrea; Nettels, Daniel; Borgia, Madeleine B; Hoffmann, Armin; Pfeil, Shawn H; Lipman, Everett A; Clarke, Jane; Schuler, Benjamin


    Theory, simulations and experimental results have suggested an important role of internal friction in the kinetics of protein folding. Recent experiments on spectrin domains provided the first evidence for a pronounced contribution of internal friction in proteins that fold on the millisecond timescale. However, it has remained unclear how this contribution is distributed along the reaction and what influence it has on the folding dynamics. Here we use a combination of single-molecule Förster resonance energy transfer, nanosecond fluorescence correlation spectroscopy, microfluidic mixing and denaturant- and viscosity-dependent protein-folding kinetics to probe internal friction in the unfolded state and at the early and late transition states of slow- and fast-folding spectrin domains. We find that the internal friction affecting the folding rates of spectrin domains is highly localized to the early transition state, suggesting an important role of rather specific interactions in the rate-limiting conformational changes.

  7. Coordination polymers of Fe(iii) and Al(iii) ions with TCA ligand: distinctive fluorescence, CO2 uptake, redox-activity and oxygen evolution reaction.

    Dhara, Barun; Sappati, Subrahmanyam; Singh, Santosh K; Kurungot, Sreekumar; Ghosh, Prasenjit; Ballav, Nirmalya


    Fe and Al belong to different groups in the periodic table, one from the p-block and the other from the d-block. In spite of their different groups, they have the similarity of exhibiting a stable 3+ oxidation state. Here we have prepared Fe(iii) and Al(iii) based coordination polymers in the form of metal-organic gels with the 4,4',4''-tricarboxyltriphenylamine (TCA) ligand, namely Fe-TCA and Al-TCA, and evaluated some important physicochemical properties. Specifically, the electrical conductivity, redox-activity, porosity, and electrocatalytic activity (oxygen evolution reaction) of the Fe-TCA system were noted to be remarkably higher than those of the Al-TCA system. As for the photophysical properties, almost complete quenching of the fluorescence originating from TCA was observed in case of the Fe-TCA system, whereas for the Al-TCA system a significant retention of fluorescence with red-shifted emission was observed. Quantum mechanical calculations based on density functional theory (DFT) were performed to unravel the origin of such discriminative behaviour of these coordination polymer systems.

  8. Fluoride uptake in dental enamel after using fluoridated dentifrice, preceded or not by a CaCl2 solution rinse Incorporação de flúor ao esmalte dentário após o uso de dentifrício fluoretado, precedido ou não por bochecho com solução de CaCl2

    Liliane Torsani Úbeda


    Full Text Available INTRODUCTION: The use of a calcium solution previously to brushing could favor the remineralization and the fluoride (F uptake in dental enamel. OBJECTIVE: This study evaluated the F in dental enamel after using a F dentifrice, preceded or not by a rinse with a CaCl2 solution. METHODS: Ten subjects (18-30 years participated in a double-blind, cross-over protocol. Enamel biopsy and 3 min saliva samples were obtained at baseline and after brushing (1.5 g Crest®, 1,000 ppm F as NaF, preceded by a rinse with 10 mL of 20 mM CaCl2 50 mM acetate pH 7.2 or deionized water, for 1 min, followed by a 15 mL water rinse for 5 sec. Biopsies were made before the rinses and after 8-15 and 120 min. Saliva samples were collected before the rinses and after 4, 15, 30, 60 and 120 min. F concentration in enamel biopsies was analyzed with the F electrode (Orion 9409 and a miniature calomel reference electrode, while phosphorus concentration was analyzed by spectrophotometry. Saliva samples were analyzed for F with the electrode (Orion 9609 by the direct method. The data were analyzed by ANOVA and Tukey test (pINTRODUÇÃO: O uso de uma solução de cálcio previamente à escovação com dentifrício fluoretado, poderia favorecer a remineralização e a incorporação de flúor ao esmalte dentário. OBJETIVOS: Este estudo avaliou a concentração de flúor no esmalte dentário após o uso de dentifrício fluoretado, precedido ou não por bochecho com solução de CaCl2. MÉTODOS: Dez voluntários (18-30 anos participaram deste estudo duplo cego e cruzado. Biópsias de esmalte e coletas de saliva de 3 min foram feitas no baseline e após a escovação com dentifrício (1,5g Crest®, 1000 ppm F, NaF, precedida por bochecho com 10mL de CaCl2 20mM, acetato 50mM, pH 7,2 ou água deionizada, durante 1 min, seguido de bochecho com 15mL de água deionizada por 5s. As biópsias foram feitas antes do bochecho e após 8-15 e 120 min. Amostras de saliva foram coletadas antes do

  9. Design of nanoengineered hybrid PVA/PNIPAm/CaCl2/SiO2-Polystyrene (PSt) colloidal crystal hydrogel coatings that sweat/rehydrate H2O from the atmosphere to give sustainable cooling and self-indicate their state

    Eloi, Jean-Charles; Worsley, Myles P.; Sermon, Paul A.; Healy, William; Dimech, Christine


    The potential for nanoengineering hybrid PVA hydrogel and hydrogel microsphere optical coatings is demonstrated with fine-tuning by the addition of (i) PNIPAm domains, (ii) water-hunting humectant CaCl2, and (ii) polystyrene or SiO2 colloidal crystals. The design and application onto substrates of the hydrogel scaffold is described. The addition of a temperature-triggered component as well as humectant and NIR reflectors are reported. The hybrid hydrogels appeared effective in sustainable adsorption cooling technology (ACT) over sustained periods. It is shown that the thermoresponsive (PNIPAm) domains act as an extra reserve, sweating water above 305K, prolonging the controlled release of water. It is also reported that the addition of humectant is crucial for the natural re-hydration of the hydrogels. For the moment PNIPAm microspheres have only short- lived ACT properties. Finally, coating with microspheres (MSs) in hydrogels produces a visible-NIR reflector effect that may allow optical feedback on ACT.

  10. Novel bipyridinyl oxadiazole-based metal coordination complexes: High efficient and green synthesis of 3,4-dihydropyrimidin-2(1H)-ones through the Biginelli reactions

    Wang, Jin-Hua; Zhang, E.; Tang, Gui-Mei; Wang, Yong-Tao; Cui, Yue-Zhi; Ng, Seik Weng


    Three new metal coordination complexes, namely, [Co(BPO)2(H2O)4](BS)2(H2O)2 (1), [Co(BPO)2(H2O)4](ABS)2(H2O)2 (2), [Co(BPO)2(H2O)4](MBS)2(H2O)2 (3) [BPO=2,5-di(pyridin-4-yl)-1,3,4-oxadiazole, BS=benzenesulphonate, ABS=4-aminobenzenesulphonate, MBS=4-methylbenzenesulphonate] were obtained under hydrothermal conditions. Complexes 1-3 were structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR and thermogravimetric analyses (TGA). All of them display a zero-dimensional motif, in which strong intermolecular hydrogen bonding interactions (O-H···O/N) and packing interactions (C-H···π and π···π) make them achieve a three-dimensional supramolecular architecture. The primary catalytic results of these three complexes show that high efficiency for the green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones was observed under solvent free conditions through Biginelli reactions. The present catalytic protocols exhibit advantages such as excellent yield, easy isolation, eco-friendly conditions, and short reaction time.

  11. Coupled 3D Time-Dependent Wave-Packet Approach in Hyperspherical Coordinates: The D(+)+H2 Reaction on the Triple-Sheeted DMBE Potential Energy Surface.

    Ghosh, Sandip; Sahoo, Tapas; Adhikari, Satrajit; Sharma, Rahul; Varandas, António J C


    We implement a coupled three-dimensional (3D) time-dependent wave packet formalism for the 4D reactive scattering problem in hyperspherical coordinates on the accurate double many body expansion (DMBE) potential energy surface (PES) for the ground and first two singlet states (1(1)A', 2(1)A', and 3(1)A') to account for nonadiabatic processes in the D(+) + H2 reaction for both zero and nonzero values of the total angular momentum (J). As the long-range interactions in D(+) + H2 contribute significantly due to nonadiabatic effects, the convergence profiles of reaction probabilities for the reactive noncharge transfer (RNCT), nonreactive charge transfer (NRCT), and reactive charge transfer (RCT) processes are shown for different collisional energies with respect to the helicity (K) and total angular momentum (J) quantum numbers. The total and state-to-state cross sections are presented as a function of the collision energy for the initial rovibrational state v = 0, j = 0 of the diatom, and the calculated cross sections compared with other theoretical and experimental results.

  12. 氯化钙诱导大豆分离蛋白冷凝胶相图与流变性质研究%Rheological properties and phase diagram of CaCl2-induced soy protein isolate cold-set gel

    刘德阳; 孔祥珍; 华欲飞; 陈业明; 张彩猛


    The phase diagram, water holding capacity(WHC) and rheological properties of CaCl2 -in-duced soy protein isolate cold-set gel under the conditions of different preheating temperatures, protein contents and salt concentrations were studied. The results showed that with the increase of preheating temperature( from 75℃ to 95℃), CaCl2 concentration which was needed to form soy protein isolate cold-set gel decreased, and under the same condition, the higher the protein content, the easier the for-mation of cold-set gel;WHC of cold-set gel had a positive correlation with protein content and nega-tive correlation with CaCl2 concentration. Under the condition of preheating temperature 85℃,the WHC of cold-set gel was the highest, while it was the lowest under the condition of preheating temperature 75℃;with the increases of protein content, preheating temperature and CaCl2 concentration, the gel strength and yield stress of the cold-set gel improved. The linear viscoelastic region of cold-set gel in-duced by 15 mmol/L CaCl2 was positively correlated with protein content,while it showed opposite trends with the increase of protein content when the cold -set gel was induced by 10 mmol/L CaCl2 . The cold-set gel induced by 15 mmol/L CaCl2 could flow with certain strain, while the cold-set gel in-duced by 10 mmol/L CaCl2 couldn’ t flow under the same condition, which indicated that the structures of cold-set gels induced by 10 mmol/L CaCl2 and 15 mmol/L CaCl2 were very different.%主要研究了CaCl2诱导大豆分离蛋白冷凝胶在不同预加热温度、蛋白质含量和盐浓度下的相图、持水性与流变性质。结果表明:随着预加热温度的升高(75~95℃),诱导大豆分离蛋白冷凝胶形成所需要的CaCl2浓度降低,且相同条件下,蛋白质含量越高,冷凝胶越易形成;冷凝胶持水性与蛋白质含量成正比,与CaCl2浓度成反比,而在85℃预加热温度下冷凝胶持水性最高,75℃预

  13. The Effect of Different Kinds of Epoxy Resin on Properties of Polyamide 6/Calcium Chloride Complex%不同种类环氧树脂对PA6/CaCl2体系性能的影响

    刘典新; 王彩红; 李诚; 郭前程; 鲁圣军


    The effects of different kinds of epoxy resin of E20 and E06 on the crystallization behavior,mechanical properties and heat-resistant properties of polyamide 6/calcium chloride complex were focused on through melting extrusion method. The results show that under the same content of epoxy resin(EP),the melting temperature,initial crystallization temperature, crystallization temperature and crystallinity of PA6/CaCl2/E20 composites are substantially lower than that value of PA6/CaCl2/E06 composites,and the crystallization limitation extent of PA6 is bigger. When EP content reach 9 phr,tensile strength of PA6/CaCl2/E20 and PA6/CaCl2/E06 composites reaches maximum (92.7 and 87.0 MPa) respectively,which is raised to 97%and 85%compared with that PA6/CaCl2 composites (47.0 MPa). When E20 and E06 content reach 3 phr and 5 phr,the impact strength(8.7 kJ/m2 and 8.7 kJ/m2) of PA6/CaCl2/E20 and PA6/CaCl2/E06 are all raised to 45%compared with that of PA6/CaCl2 composites (6.0 kJ/m2). After adding suitable amount of E20 and E06,heat resistance of composites are significantly improved,and the declining extent of thermal stability is small. In conclusion,under suitable amount of E20,PA6/CaCl2/E20 composite has the better mechanical and heat-resistant properties.%利用熔融挤出法研究了两种不同环氧值的环氧树脂(E20,E06)对PA6/CaCl2复合体系的结晶、力学、耐热性能的影响。结果表明,在相同环氧树脂含量下,PA6/CaCl2/E20复合材料的熔融温度、起始结晶温度、结晶峰温度、结晶度大体上低于PA6/CaCl2/E06复合材料的值,PA6的结晶受限程度也较大。当EP含量为9份时,PA6/CaCl2/E20与PA6/CaCl2/E06复合材料的拉伸强度均达到最大值(92.7,87.0 MPa),与PA6/CaCl2(47.0 MPa)相比提高了97%和85%。当E20,E06含量分别为3份、5份时,PA6/CaCl2/EP复合材料的冲击强度分别达到最大值8.7,8.7 kJ/m2,与PA6/CaCl2(6.0 kJ/m2)相比提高了45%。另外,加入适量E20

  14. A New Bioinspired Perchlorate Reduction Catalyst with Significantly Enhanced Stability via Rational Tuning of Rhenium Coordination Chemistry and Heterogeneous Reaction Pathway.

    Liu, Jinyong; Han, Mengwei; Wu, Dimao; Chen, Xi; Choe, Jong Kwon; Werth, Charles J; Strathmann, Timothy J


    Rapid reduction of aqueous ClO4(-) to Cl(-) by H2 has been realized by a heterogeneous Re(hoz)2-Pd/C catalyst integrating Re(O)(hoz)2Cl complex (hoz = oxazolinyl-phenolato bidentate ligand) and Pd nanoparticles on carbon support, but ClOx(-) intermediates formed during reactions with concentrated ClO4(-) promote irreversible Re complex decomposition and catalyst deactivation. The original catalyst design mimics the microbial ClO4(-) reductase, which integrates Mo(MGD)2 complex (MGD = molybdopterin guanine dinucleotide) for oxygen atom transfer (OAT). Perchlorate-reducing microorganisms employ a separate enzyme, chlorite dismutase, to prevent accumulation of the destructive ClO2(-) intermediate. The structural intricacy of MGD ligand and the two-enzyme mechanism for microbial ClO4(-) reduction inspired us to improve catalyst stability by rationally tuning Re ligand structure and adding a ClOx(-) scavenger. Two new Re complexes, Re(O)(htz)2Cl and Re(O)(hoz)(htz)Cl (htz = thiazolinyl-phenolato bidentate ligand), significantly mitigate Re complex decomposition by slightly lowering the OAT activity when immobilized in Pd/C. Further stability enhancement is then obtained by switching the nanoparticles from Pd to Rh, which exhibits high reactivity with ClOx(-) intermediates and thus prevents their deactivating reaction with the Re complex. Compared to Re(hoz)2-Pd/C, the new Re(hoz)(htz)-Rh/C catalyst exhibits similar ClO4(-) reduction activity but superior stability, evidenced by a decrease of Re leaching from 37% to 0.25% and stability of surface Re speciation following the treatment of a concentrated "challenge" solution containing 1000 ppm of ClO4(-). This work demonstrates the pivotal roles of coordination chemistry control and tuning of individual catalyst components for achieving both high activity and stability in environmental catalyst applications.

  15. Temporal coordination between ground reaction forces generated by leading and trailing limbs for propulsion during double stance phase in human walking.

    Sato, Yoichiro; Yamada, Norimasa


    Although it was reported that ground reaction forces (GRFs) are generated simultaneously by the leading and trailing limbs during the double stance phase, the finding was not examined by temporal analyses. Therefore, the purpose of the present study is to clarify how GRFs can act to propel the body in a forward direction during the double stance phase. GRFs were recorded during the double stance phase in eleven healthy volunteers. We calculated the instantaneous phase of the GRFs for vertical and anterior-posterior (AP) components, and then calculated the relative phase between the leading and trailing limbs for each component. The relative phase of the vertical component was approximately 180° (i.e., anti-phase), indicating that the lower limb transfers weight smoothly from the trailing limb to the leading limb. The relative phase of the AP component ranged from 40 to 55°, indicating that the AP component of the forces do not occur simultaneously, but instead has a lag. This finding suggests that the forces exerted by the leading and trailing limbs would temporally coordinate to propel the body in the forward direction. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 氯化镧与甘氨酸配位反应的热化学研究%Thermochemical Study of the Reaction of Lanthanum Chloride Coordinated with Glycine

    周传佩; 陈文生; 刘义; 李林尉; 屈松生


    The reaction enthalpy of coordination reaction of lanthanum chloride with Glycine is determined by solution calorimetry in an isoperibel reaction calorimeter. The calormetric solvent is the solution of hydrochloric acid (2 mol·L- 1), a new thermochemical cycle is designed. According to the results, the following date:()(298.2 K)=- 4.310 kJ·mol- 1()(La(Gly)3Cl3· 5H2O, s, 298.2 K)=- 4222.93 kJ·mol- 1 were obtained.


    温德才; 刘义; 胡立新; 李昕; 屈松生


    The reaction enthalpy of solid-solid coordination reaction of 8-hoxine with zinc acetate is determined by solution calorimetry in an isoperibel reaction calorimeter. The calorimetric solvent is the solution of hydrochloric acid (4 mol·L-1). According to the results, the value ΔrH(-○m)=-1.002 kJ·mol-1ΔfH(-○m)(Zn(oxin)2·H2O)=-582.123 kJ·mol-1 are recommended.

  18. Phase boundary between rutile-type and CaCl2-type in SiO2 and GeO2 determined by in situ X-ray observations

    Ono, S.


    The physical properties and structural evolution of SiO2 at high pressures have attracted attention in the geophysical community because stishovite is one of minerals in the subducted oceanic crust which seems to subduct into the lower mantle. Recently some groups have claimed the disproportionation of Mg-perovskite into MgO and SiO2. If orthorhombic Mg-perovskite breaks down in the lower mantle, SiO2 could be an important mineral to clear the structure and dynamics in the lower mantle. Although detailed knowledge has been accumulated on the high-pressure behavior of SiO2, most data have been limited to room temperature and high pressure. In situ observation at high P-T is required to determine the phase boundary in SiO2, because the orthorhombic (CaCl2-type) phase is unquenchable, converting to the tetragonal (rutile-type) phase on release of pressure. In situ synchrotron X-ray experiments in the system SiO2 and GeO2 were made under pressures of 25-100 GPa and temperatures of 300-2300 K, using a laser-heated diamond anvil cell (LHDAC) technique. Platinum powder was mixed with the sample in order to absorb laser radiation for heating and to provide an internal pressure calibrant. The samples were heated with a multimode continuous wave Nd:YAG laser using double-sided laser heating techniques. The sample temperature was measured from one side of the sample using the spectroradiometric method. The heated samples were probed by angle-dispersive X-ray diffraction using the synchrotron beam line BL10XU at SPring-8 in Japan. I observed the second-order phase transition between the tetragonal rutile-type ( P42/mnm ) and the orthorhombic CaCl2-type ( Pnnm ) phases under high P-T. The transition showed the positive temperature dependence of the transition pressure. The phase boundary in GeO2, which is regarded as an analogue of SiO2, was determined to be P (GPa) = (35 +/- 1) + (0.009 +/- 0.003) x (T - 1300) (K) . The phase boundary in SiO2 was determined to be P (GPa) = (51

  19. 5%氯化钙存在下高硫煤还原磷石膏实验研究%Study on reducing phosphogypsum by high-sulfur coal in presence of 5% CaCl2

    吴雨龙; 吴穹


    Phosphogypsum,waste slag derived from phosphate fertilizer industry doping with 5%(mass fraction) CaCl2 was used as raw material, purged with N2 and then calcined under the presence of high-sulfur coal as reductant to prepare CaS and CaO.The contents of CaS and CaO in the product were analyzed by iodine quantity method so as to investigate the reduction rate of calcium sulfate.The effects of raw material mix ratio, calcining time, calcining temperature, and particle size etc. on the reduction of phosphogypsum were studied.Based on these studies, orthogonal experiments were conducted to find out the optimum process conditions for obtaining CaS and CaO by reducing phosphogypsum,which are as follows: amount-of-substance ratio of CaSO4 to C was 1:1.3, calcining temperature was 900℃. ,and calcining time was 2.5 h. Under those conditions the reduction rate of CaSO4 in phosphogypsum could reach more than 98%.The doping of 5% CaCl2could decline the reductive decomposition temperature of phosphogypsum.%以磷肥工业废渣磷石膏为原料,在磷石膏中掺入5%氯化钙(以质量分数计),以高硫煤为还原剂,在氮气吹净空气后焙烧还原磷石膏制备硫化钙、氧化钙,并采用碘量法分析产物中硫化钙、氧化钙的含量,考察硫酸钙的还原率.研究了原料配比、焙烧时间、焙烧温度、颗粒细度等因素对还原磷石膏的影响.在此基础上进行了正交实验,得到还原磷石膏制备硫化钙、氧化钙的优化工艺条件:硫酸钙与碳物质的量比为1:1.3、焙烧温度为900℃、焙烧时间为2.5 h,在此条件下,磷石膏中硫酸钙的还原率可达到98%以上.在磷石膏中掺入5%氯化钙能降低磷石膏的还原分解温度.

  20. Discovery and synthetic applications of novel silicon-carbon bond cleavage reactions based on the coordination number change of organosilicon compounds

    Tamao, Kohei


    Some synthetically useful transformations of organosilicon compounds have been developed since the mid 1970s, based on the new concept that the silicon-carbon bonds are activated toward electrophilic cleavage via the formation of penta- and hexa-coordinate species. This review mainly consists of the following aspects: (1) a general concept for the activation of the silicon-carbon bond via penta- and hexa-coordinate species, (2) synthetic application of hexa-coordinate organopentafluorosilicat...

  1. Monazite Alteration in H2O ± HCl ± NaCl ± CaCl2 Fluids at 150 ºC and psat: Implications for Uranium Deposits

    Antonin Richard


    Full Text Available Spectacular alteration of monazite by diagenetic/hydrothermal brines is well documented in some Proterozoic sedimentary basins in close relationship with high-grade uranium (U deposits. Hence, monazite has been proposed as a viable source for some U deposits. However, monazite alteration remains enigmatic with regard to its high stability in relatively low temperature hydrothermal conditions. Here, the results of batch experiments in which 10 mg of natural monazite grains were reacted with 15 mL of Na-Ca-Cl (6 molal Cl solutions as well as in pure water at 150 ºC and saturated vapor pressure (psat for one and six months are reported. The influence of pH (pH = 1, 3, 7 and relative molar proportions of Na and Ca (Na/(Na + Ca = 0, 0.5, 1, were tested. Discrete alteration features (etch pits and roughened surfaces appear in a minority of the one month experiments and are more developed in the six months experiments, especially at pH = 1 and 3. Although spectacular alteration of monazite, as seen around U deposits, could not be reproduced here, this study shows that monazite is unstable in the presence of fluids analogous to acidic deep basinal brines.

  2. New class of phosphine oxide donor-based supramolecular coordination complexes from an in situ phosphine oxidation reaction or phosphine oxide ligands.

    Shankar, Bhaskaran; Elumalai, Palani; Shanmugam, Ramasamy; Singh, Virender; Masram, Dhanraj T; Sathiyendiran, Malaichamy


    A one-pot, multicomponent, coordination-driven self-assembly approach was used to synthesize the first examples of neutral bridging phosphine oxide donor-based supramolecular coordination complexes. The complexes were self-assembled from a fac-Re(CO)3 acceptor, an anionic bridging O donor, and a neutral soft phosphine or hard phosphine oxide donor.

  3. Ca^2+、ABA预处理蝴蝶兰类原球茎的脱水保护系统比较及信号传导关系%Comparison on the Dehydration Protection Systems and Signal Transduction Relationship of CaCl2 and ABA Pretreatment on the Phalaenopsis PLB



    CaCl2和ABA溶液及两者联合分别预处理蝴蝶兰类原球茎(PLB)后脱水,对比PLB脱水前后的成活率、脱水保护系统指标变化及Ca^2+与ABA信号传导关系。结果表明,CaCl2和ABA溶液及两者联合预处理均能明显提高PLB脱水后的成活率。CaCl2和ABA溶液对可溶性糖、蔗糖、还原糖、SOD和总抗氧化能力有相同的效应趋势,对可溶性蛋白、热稳定蛋白含量及POD、CAT活性的作用趋势有所差异。ABA溶液提高PLB耐脱水性的能力被胞质Ca^2+螯合剂BAPT~AM和钙调蛋白拮抗剂氯丙嗪所削弱,Ca^2+预处理提高PLB耐脱水能力被ABA合成抑制剂环丙嘧啶醇削弱。在蝴蝶兰PLB的耐脱水性诱导中,Ca^2+和ABA具有基本相同的生理生化基础,在信号传递中两者互相关联,CaCl2取代ABA用于提高PLB耐脱水性是可行的。%In this paper we pretreated Phalaenopsis PLB (protocorm-like body) with CaCl2, ABA and both, respectively, and compared survival rate, dehydration protection system before and after desiccation, as well as the signal transduction relationship between Ca〉 and ABA. The results showed survival rates of dehydrated PLB pretreated with CaCl2, ABA and both all increased significantly. CaCl2 and ABA exhibited similar impact tendencies on the indexes of soluble carbohydrate, sucrose, reducing carbohydrate, SOD activity and antioxidative capability, respectively, but with respect to the indexes of soluble protein, heat-stable protein, POD and CAT, their impact tendencies showed deviation. The ability that ABA increased the dehydration tolerance of PLB was weaken by promethazine (calmodulin antagonist) or BAPTA/AM (cytosolic calcium chelator). Ancymidol (inhibitor of ABA synthesis) decreased the effect of ABA on the PLB's dehydration tolerance. Due to the fact that the effects of CaCl2 and ABA had almost the same basic of physiology and biochemistry, and that ABA and Ca〉 related to

  4. Comparison on the Dehydration Protection Systems and Signal Transduction Relationship of CaCl2 and ABA Pretreatment on the Phalaenopsis PLB%Ca2+、ABA预处理蝴蝶兰类原球茎的脱水保护系统比较及信号传导关系



    In this paper we pretreated Phalaenopsis PLB (protocorm-like body) with CaCl2, ABA and both, respectively, and compared survival rate, dehydration protection system before and after desiccation, as well as the signal transduction relationship between Ca2+ and ABA. The results showed survival rates of dehydrated PLB pretreated with CaCl2, ABA and both all increased significantly. CaCl2 and ABA exhibited similar impact tendencies on the indexes of soluble carbohydrate, sucrose, reducing carbohydrate, SOD activity and antioxidative capability, respectively, but with respect to the indexes of soluble protein, heat-stable protein, POD and CAT, their impact tendencies showed deviation. The ability that ABA increased the dehydration tolerance of PLB was weaken by promethazine (calmodulin antagonist) or BAPTA/AM (cytosolic calcium chelator). Ancymidol (inhibitor of ABA synthesis) decreased the effect of ABA on the PLB's dehydration tolerance. Due to the fact that the effects of CaCl2 and ABA had almost the same basic of physiology and biochemistry, and that ABA and Ca2+ related to each other by the signal transduction system during dehydration, it is practical to replace ABA with CaCl2 for pretreatment to induce the dehydration tolerance of Phalaenopsis PLB.%CaCl2和ABA溶液及两者联合分别预处理蝴蝶兰类原球茎(PLB)后脱水,对比PLB脱水前后的成活率、脱水保护系统指标变化及Ca2+与ABA信号传导关系.结果表明,CaCl2和ABA溶液及两者联合预处理均能明显提高PLB脱水后的成活率.CaCl2和ABA溶液对可溶性糖、蔗糖、还原糖、SOD和总抗氧化能力有相同的效应趋势,对可溶性蛋白、热稳定蛋白含量及POD、CAT活性的作用趋势有所差异.ABA溶液提高PLB耐脱水性的能力被胞质Ca2+ 螯合剂BAPTA/AM 和钙调蛋白拮抗剂氯丙嗪所削弱,Ca2+预处理提高PLB耐脱水能力被ABA合成抑制剂环丙嘧啶醇削弱.在蝴蝶兰PLB的耐脱水性诱导中,Ca2+和ABA具有基本

  5. Systematic Investigation of Reaction-Time Dependence of Three Series of Copper-Lanthanide/Lanthanide Coordination Polymers: Syntheses, Structures, Photoluminescence, and Magnetism.

    Zhang, Ju-Wen; Kan, Xiao-Min; Liu, Bin-Qiu; Liu, Guo-Cheng; Tian, Ai-Xiang; Wang, Xiu-Li


    Three series of copper-lanthanide/lanthanide coordination polymers (CPs) Ln(III) Cu(II) Cu(I) (bct)3 (H2 O)2 [Ln=La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Er (10), Yb (11), and Lu (12), H2 bct=2,5-bis(carboxymethylmercapto)-1,3,4-thiadiazole acid], Ln(III) Cu(I) (bct)2 [Ln=Ce (2 a), Pr (3 a), Nd (4 a), Sm (5 a), Eu (6 a), Gd (7 a), Tb (8 a), Dy (9 a), Er (10 a), Yb (11 a), and Lu (12 a)], and Ln(III) 2 (bct)3 (H2 O)5 [Ln=La (1 b), Ce (2 b), Pr (3 b), Nd (4 b), Sm (5 b), Eu (6 b), Gd (7 b), Tb (8 b), and Dy (9 b)] have been successfully constructed under hydrothermal conditions by modulating the reaction time. Structural characterization has revealed that CPs 1-12 possess a unique one-dimensional (1D) strip-shaped structure containing two types of double-helical chains and a double-helical channel. CPs 2 a-12 a show a three-dimensional (3D) framework formed by Cu(I) linking two types of homochiral layers with double-helical channels. CPs 1 b-9 b exhibit a 3D framework with single-helical channels. CPs 6 b and 8 b display visible red and green luminescence of the Eu(III) and Tb(III) ions, respectively, sensitized by the bct ligand, and microsecond-level lifetimes. CP 8 b shows a rare magnetic transition between short-range ferromagnetic ordering at 110 K and long-range ferromagnetic ordering below 10 K. CPs 9 a and 9 b display field-induced single-chain magnet (SCM) and/or single-molecule magnet (SMM) behaviors, with Ueff values of 51.7 and 36.5 K, respectively.

  6. Preparation of Porous Anodic Alumina/Zinc Oxide Nanowire Arrays by a Coordination Reaction Method%利用配位反应法制备多孔阳极氧化铝/氧化锌纳米线阵列

    张灵翠; 阮永丰; 王丹丽; 邱春霞


    A novel method named “coordination reaction method” was developed to fabricate zinc oxide (ZnO) nanowire arrays. The ZnO nanowires in the holes of the porous anodic alumina (PAA) template were synthesized with ammonia as a coordination agent and zinc- amino complex as a precursor by the coordination reaction method. The growth mechanism of ZnO nanowires and the conditions of the coordination reaction were also discussed. The microstructures and morphology of PAA/ZnO assembly were characterized by X-ray diffractometer, scanning electron microscope and transmission electron microscope. The results show that the ZnO nanowires prepared are a polycrystalline structure, and the nanowire arrays possess a periodic array of structure with the same morphological characteristics of PAA template.%研究了一种新型的制备氧化锌(ZnO)纳米线的配位反应法.以氨水为配位剂、氨水与可溶性的锌盐反应配制的锌氨配合物溶液为前驱液,在多孔阳极氧化铝(porous anodic alumina,PAA)模板中沉积了ZnO纳米线.研究了ZnO纳米线的生长机理和配位反应条件.用X射线衍射仪、扫描电子显微镜和透射电子显微镜对PAA/ZnO组装体的组成和形貌进行了表征.结果表明:所制备的ZnO纳米线为多晶结构,纳米线阵列具有周期排列结构,与多孔氧化铝模板形态特征一致.

  7. A molecular orbital study of a model of the Mg2+ coordination complex of the self splicing reaction of ribosomal RNA

    McCourt, M.; Shibata, M.; McIver, J. W.; Rein, R.


    Recent discoveries have established the fact that RNA is capable of acting as an enzyme. In this study two different types of molecular orbital calculations, INDO and ab initio, were used in an attempt to assess the structural/functional role of the Mg2+ hydrated complex in ribozyme reactions. Preliminary studies indicate that the reaction is multistep and that the Mg2+ complex exerts a stabilizing effect on the intermediate or midpoint of the reaction.

  8. Carbon-carbon cross-coupling reactions catalyzed by a two-coordinate nickel(II)-bis(amido) complex via observable Ni(I) , Ni(II) , and Ni(III) intermediates.

    Lipschutz, Michael I; Tilley, T Don


    Recently, the development of more sustainable catalytic systems based on abundant first-row metals, especially nickel, for cross-coupling reactions has attracted significant interest. One of the key intermediates invoked in these reactions is a Ni(III) -alkyl species, but no such species that is part of a competent catalytic cycle has yet been isolated. Herein, we report a carbon-carbon cross-coupling system based on a two-coordinate Ni(II) -bis(amido) complex in which a Ni(III) -alkyl species can be isolated and fully characterized. This study details compelling experimental evidence of the role played by this Ni(III) -alkyl species as well as those of other key Ni(I) and Ni(II) intermediates. The catalytic cycle described herein is also one of the first examples of a two-coordinate complex that competently catalyzes an organic transformation, potentially leading to a new class of catalysts based on the unique ability of first-row transition metals to accommodate two-coordinate complexes.

  9. Testing the nature of reaction coordinate describing interaction of H2 with carbonyl carbon, activated by Lewis acid complexation, and the Lewis basic solvent: A Born-Oppenheimer molecular dynamics study with explicit solvent

    Heshmat, Mojgan; Privalov, Timofei


    Using Born-Oppenheimer molecular dynamics (BOMD), we explore the nature of interactions between H2 and the activated carbonyl carbon, C(carbonyl), of the acetone-B(C6F5)3 adduct surrounded by an explicit solvent (1,4-dioxane). BOMD simulations at finite (non-zero) temperature with an explicit solvent produced long-lasting instances of significant vibrational perturbation of the H—H bond and H2-polarization at C(carbonyl). As far as the characteristics of H2 are concerned, the dynamical transient state approximates the transition-state of the heterolytic H2-cleavage. The culprit is the concerted interactions of H2 with C(carbonyl) and a number of Lewis basic solvent molecules—i.e., the concerted C(carbonyl)⋯H2⋯solvent interactions. On one hand, the results presented herein complement the mechanistic insight gained from our recent transition-state calculations, reported separately from this article. But on the other hand, we now indicate that an idea of the sufficiency of just one simple reaction coordinate in solution-phase reactions can be too simplistic and misleading. This article goes in the footsteps of the rapidly strengthening approach of investigating molecular interactions in large molecular systems via "computational experimentation" employing, primarily, ab initio molecular dynamics describing reactants-interaction without constraints of the preordained reaction coordinate and/or foreknowledge of the sampling order parameters.

  10. WHO co-ordinated short-term double-blind trial with thalidomide in the treatment of acute lepra reactions in male lepromatous patients.

    Iyer, C G; Languillon, J; Ramanujam, K; Tarabini-Castellani, G; De las Aguas, J T; Bechelli, L M; Uemura, K; Martinez Dominguez, V; Sundaresan, T


    The treatment of lepra reactions constitutes one of the most serious problems in leprosy. For this reason, the first reports in 1965 of the favourable results obtained with thalidomide aroused considerable interest and led WHO, in 1967, to carry out a trial with the co-operation of four centres. A short-term double-blind trial was designed to study the effect of thalidomide, in comparison with acetylsalicylic acid, in the treatment of acute lepra reactions in male lepromatous patients. Acetylsalicylic acid was used instead of a placebo because of its antipyretic and analgesic activity. Because of the severe adverse reactions that may be caused by thalidomide, mainly the teratogenic effects, only males were included in the trial.The results of this short-term study seem to confirm previous reports of the efficacy of thalidomide and indicate that acetylsalicylic acid also seems to be helpful in the management of certain symptoms of lepra reactions.

  11. Hydrogen transfer reactions in viscous media — Potential and free energy surfaces in solvent–solute coordinates and their kinetic implications

    Wiebe, Heather; Prachnau, Melissa; Weinberg, Noham


    Two-dimensional potential energy and free energy surfaces are obtained using quantum mechanical and molecular dynamics calculations for four hydrogen transfer reactions in n-hexane solvent: the methyl–methane, n-propyl–n-propane, n-pentyl...

  12. Poisson Coordinates.

    Li, Xian-Ying; Hu, Shi-Min


    Harmonic functions are the critical points of a Dirichlet energy functional, the linear projections of conformal maps. They play an important role in computer graphics, particularly for gradient-domain image processing and shape-preserving geometric computation. We propose Poisson coordinates, a novel transfinite interpolation scheme based on the Poisson integral formula, as a rapid way to estimate a harmonic function on a certain domain with desired boundary values. Poisson coordinates are an extension of the Mean Value coordinates (MVCs) which inherit their linear precision, smoothness, and kernel positivity. We give explicit formulas for Poisson coordinates in both continuous and 2D discrete forms. Superior to MVCs, Poisson coordinates are proved to be pseudoharmonic (i.e., they reproduce harmonic functions on n-dimensional balls). Our experimental results show that Poisson coordinates have lower Dirichlet energies than MVCs on a number of typical 2D domains (particularly convex domains). As well as presenting a formula, our approach provides useful insights for further studies on coordinates-based interpolation and fast estimation of harmonic functions.

  13. Reactions with a Metalloid Tin Cluster {Sn10[Si(SiMe3)3]4}(2-): Ligand Elimination versus Coordination Chemistry.

    Schrenk, Claudio; Gerke, Birgit; Pöttgen, Rainer; Clayborne, Andre; Schnepf, Andreas


    Chemistry that uses metalloid tin clusters as a starting material is of fundamental interest towards understanding the reactivity of such compounds. Since we identified {Sn10[Si(SiMe3)3]4}(2-) 7 as an ideal candidate for such reactions, we present a further step in the understanding of metalloid tin cluster chemistry. In contrast to germanium chemistry, ligand elimination seems to be a major reaction channel, which leads to the more open metalloid cluster {Sn10[Si(SiMe3)3]3}(-) 9, in which the Sn core is only shielded by three Si(SiMe3)3 ligands. Compound 9 is obtained through different routes and is crystallised together with two different countercations. Besides the structural characterisation of this novel metalloid tin cluster, the electronic structure is analysed by (119)Sn Mössbauer spectroscopy. Additionally, possible reaction pathways are discussed. The presented first step into the chemistry of metalloid tin clusters thus indicates that, with respect to metalloid germanium clusters, more reaction channels are accessible, thereby leading to a more complex reaction system.

  14. Light-Induced Copper(II) Coordination by a Bicyclic Tetraaza Chelator through a Ligand-to-Metal Charge-Transfer Reaction

    Holm-Jørgensen, Jacob Rørdam; Jensen, Mikael; Bjerrum, Morten


    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values...... and high temperatures are applied. We have investigated the effects of the variation in the pH, different anions, and UV irradiation on the chelation rate. UV spectra of mixtures of Cu2+ and [24.31]adz in water show the existence of a longlived two-coordinated copper(II) intermediate (only counting...

  15. Quantifying mixing using equilibrium reactions

    Wheat, Philip M.; Posner, Jonathan D.


    A method of quantifying equilibrium reactions in a microchannel using a fluorometric reaction of Fluo-4 and Ca2+ ions is presented. Under the proper conditions, equilibrium reactions can be used to quantify fluid mixing without the challenges associated with constituent mixing measures such as limited imaging spatial resolution and viewing angle coupled with three-dimensional structure. Quantitative measurements of CaCl and calcium-indicating fluorescent dye Fluo-4 mixing are measured in Y-shaped microchannels. Reactant and product concentration distributions are modeled using Green's function solutions and a numerical solution to the advection-diffusion equation. Equilibrium reactions provide for an unambiguous, quantitative measure of mixing when the reactant concentrations are greater than 100 times their dissociation constant and the diffusivities are equal. At lower concentrations and for dissimilar diffusivities, the area averaged fluorescence signal reaches a maximum before the species have interdiffused, suggesting that reactant concentrations and diffusivities must be carefully selected to provide unambiguous, quantitative mixing measures. Fluorometric equilibrium reactions work over a wide range of pH and background concentrations such that they can be used for a wide variety of fluid mixing measures including industrial or microscale flows.

  16. Coordination of NO(2)(-) ligand to Cu(I) ion in an O,O-bidentate fashion that evolves NO gas upon protonation: a model reaction relevant to the denitrification process.

    Chen, Chi-Shian; Yeh, Wen-Yann


    [(2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N)(2)Cu(2)](BF(4))(2) (2) has been prepared by treating 2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N (1) with [Cu(NCMe)(4)]BF(4). Reaction of 2 and [Ph(3)PNPPh(3)]NO(2) produces (2,6-(Ph(2)P(o-C(6)H(4))CH=N)(2)C(5)H(3)N)Cu(NO(2)) (3), with the nitrite ligand in a unique eta(2)-O,O coordination mode. Protonation of 3 releases NO gas, which mimics the reactivity of the Type 2 Cu-NiRs.

  17. Preparation, Crystal Structure and Enthalpy Change of Formation of the Reaction in Liquid Phase of a New Three-Dimensional Mixed-Ligand Holmium(Ⅲ) Coordination Polymer Based on Strong π-π Stacking Interactions

    REN,Yi-Xia; CHEN,San-Ping; GAO,Sheng-Li


    A new three-dimensional coordination polymer, [Ho(5-nip)(phen)(NO3)(DMF)] (5-nip=5-nitroisophthalic acid and phen=1,10-phenanthroline), was prepared and characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum and DTG-DSC techniques. The results show that the title complex crystallizes in space group P2/m with a= 1.0906(3) nm, b=1.2804 (3) nm, c= 1.6987(4) nm,β=91.400(5)°, Z=4, Dc= 1.931 Mg/m3, F(000)=1352. Each Ho(Ⅲ) ion is nine-coordinated by one chelating bidentate and two monodentate bridging carboxylate groups, one chelating bidentate NO3- anion, one DMF molecule and one 1,10-phenanthroline molecule. The complex is constructed with one-dimensional ribbons featuring dinuclear units and the one-dimensional ribbons are further assembled into two-dimensional networks by strong π-π stacking interactions with the distance of 0.327 nm,then the networks are arranged into three-dimensional structure according to ABAB fashion. The complex exhibits high stability up to 600 ℃. Its enthalpy change of formation of the reaction in liquid-phase in solvent DMF was measured using an RD496-Ⅲ type microcalorimeter with a value of (-11.016±0.184) kJ·mol-1.

  18. Synthesis, Characterization, and Crystal Structure of a Novel Copper(II) Complex with an Asymmetric Coordinated 2,2'-Bipyridine Derivative: A Model for the Associative Complex in the Ligand-Substitution Reactions of [Cu(tren)L](2+)?

    Lu Zl, Zhong-lin; Duan Cy, Chun-ying; Tian Yp, Yu-peng; You Xz, Xiao-zeng; Huang Xy, Xiao-ying


    The titled compound, (tris(2-aminoethyl)amine)(4,5-diazafluoren-9-one) copper(II) perchlorate, [Cu(C(6)H(18)N(4))(C(11)H(6)N(2)O)(ClO(4))(2)], 1, has been designed, synthesized, and characterized. The electronic and ESR spectra are very different from those of [Cu(tren)L](2+) complexes where L is monodentate ligand. The X-ray analysis revealed that the complex crystallizes in the monoclinic space group P2(1)/c, with a = 10.726(6) Å, b = 14.921(7) Å, c = 14.649(4) Å, beta = 95.13(3) degrees, and Z = 4. The copper(II) ion is coordinated by four nitrogen atoms from tris(2-aminoethyl)amine (tren) and two nitrogen atoms from 4,5-diazafluoren-9-one (dzf) to form an unusual six-coordinate (4 + 1 + 1') geometry. The structure is very rare, and to our knowledge, it is the first example of an asymmetric bidentate phenanthroline derivative metal complex. The structure could be used as a model of the associative complex in the ligand-exchange and ligand-substitution reactions of [Cu(tren)L](2+) and the catalytic mechanisms of enzymes involving copper sites. From the electronic and variable-temperature ESR spectra in solution, the possible mechanism of these reactions has also been proposed. As a comparison, the complex [Cu(tren)(ImH)(ClO(4))(2)], 2, was also synthesized and characterized, where ImH is imidazole.


    A. Ball

    Overview From a technical perspective, CMS has been in “beam operation” state since 6th November. The detector is fully closed with all components operational and the magnetic field is normally at the nominal 3.8T. The UXC cavern is normally closed with the radiation veto set. Access to UXC is now only possible during downtimes of LHC. Such accesses must be carefully planned, documented and carried out in agreement with CMS Technical Coordination, Experimental Area Management, LHC programme coordination and the CCC. Material flow in and out of UXC is now strictly controlled. Access to USC remains possible at any time, although, for safety reasons, it is necessary to register with the shift crew in the control room before going down.It is obligatory for all material leaving UXC to pass through the underground buffer zone for RP scanning, database entry and appropriate labeling for traceability. Technical coordination (notably Stephane Bally and Christoph Schaefer), the shift crew and run ...

  20. Atomic resolution structures of discrete stages on the reaction coordinate of the [Fe4S4] enzyme IspG (GcpE)

    Quitterer, Felix


    IspG is the penultimate enzyme in non-mevalonate biosynthesis of the universal terpene building blocks isopentenyl diphosphate and dimethylallyl diphosphate. Its mechanism of action has been the subject of numerous studies but remained unresolved due to difficulties in identifying distinct reaction intermediates. Using a moderate reducing agent as well as an epoxide substrate analogue, we were now able to trap and crystallographically characterize various stages in the IspG catalyzed conversion of 2-C-methyl-D-erythritol-2,4-cyclo-diphosphate (MEcPP) to (E)-1-hydroxy-2-methylbut-2-enyl-4-diphosphate (HMBPP). In addition, the enzyme’s structure was determined in complex with several inhibitors. These results, combined with recent electron paramagnetic resonance data, allowed us to deduce a detailed and complete IspG catalytic mechanism which describes all stages from initial ring opening to formation of HMBPP via discrete radical and carbanion intermediates. The data presented in this article provide a guide for the design of selective drugs against many pro- and eukaryotic pathogens to which the non-mevalonate pathway is essential for survival and virulence.

  1. Effect of head and neck position on vertical ground reaction forces and interlimb coordination in the dressage horse ridden at walk and trot on a treadmill.

    Weishaupt, M A; Wiestner, T; von Peinen, K; Waldern, N; Roepstorff, L; van Weeren, R; Meyer, H; Johnston, C


    Little is known in quantitative terms about the influence of different head-neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for injury. To improve the understanding of forelimb-hindlimb balance and its underlying temporal changes in relation to different head and neck positions. Vertical ground reaction force and time parameters of each limb were measured in 7 high level dressage horses while being ridden at walk and trot on an instrumented treadmill in 6 predetermined HNPs: HNP1 - free, unrestrained with loose reins; HNP2 - neck raised, bridge of the nose in front of the vertical; HNP3 - neck raised, bridge of the nose behind the vertical; HNP4 - neck lowered and flexed, bridge of the nose considerably behind the vertical; HNP5 - neck extremely elevated and bridge of the nose considerably in front of the vertical; HNP6 - neck and head extended forward and downward. Positions were judged by a qualified dressage judge. HNPs were assessed by comparing the data to a velocity-matched reference HNP (HNP2). Differences were tested using paired t test or Wilcoxon signed rank test (Pwalk, stride duration and overreach distance increased in HNP1, but decreased in HNP3 and HNP5. Stride impulse was shifted to the forehand in HNP1 and HNP6, but shifted to the hindquarters in HNP5. At the trot, stride duration increased in HNP4 and HNP5. Overreach distance was shorter in HNP4. Stride impulse shifted to the hindquarters in HNP5. In HNP1 peak forces decreased in the forelimbs; in HNP5 peak forces increased in fore- and hindlimbs. HNP5 had the biggest impact on limb timing and load distribution and behaved inversely to HNP1 and HNP6. Shortening of forelimb stance duration in HNP5 increased peak forces although the percentage of stride impulse carried by the forelimbs decreased. An extremely high HNP affects functionality much


    A. Ball


    Operational Experience At the end of the first full-year running period of LHC, CMS is established as a reliable, robust and mature experiment. In particular common systems and infrastructure faults accounted for <0.6 % CMS downtime during LHC pp physics. Technical operation throughout the entire year was rather smooth, the main faults requiring UXC access being sub-detector power systems and rack-cooling turbines. All such problems were corrected during scheduled technical stops, in the shadow of tunnel access needed by the LHC, or in negotiated accesses or access extensions. Nevertheless, the number of necessary accesses to the UXC averaged more than one per week and the technical stops were inevitably packed with work packages, typically 30 being executed within a few days, placing a high load on the coordination and area management teams. It is an appropriate moment for CMS Technical Coordination to thank all those in many CERN departments and in the Collaboration, who were involved in CMS techni...

  3. Spectral Study on Coordination Reaction between metMyoglobin and Nitric Oxide%光谱法研究高铁肌红蛋白活性中心与一氧化氮的配位反应

    唐乾; 张越; 曹洪玉; 史珊珊; 郑学仿


    As we all known ,the instantaneous reaction between protein and ligands are very important to adjust the normal pla‐ying of biological function .And nitric oxide interactions with iron are the most important biological reactions in which NO partic‐ipates .Unlike carbon monoxide or oxygen ,NO can also bind reversibly to ferric iron .In this paper ,UV‐Vis absorption and CD spectra were used to study coordination reaction process between horse heart metMb and NO ,to demonstrate the coordination reaction mechanism and to explore the influencing factors of metMb with NO .The experimental results showed that metMb could react with NO ,and obtained three new peaks at 420 nm ,534 and 568 nm ,respectively ,which implied metMb and NO have reacted and generated a new complex‐nitrosylmetmyoglobin (metMbNO) .Then as time went on ,NO concentration de‐creased in the solution ,and the Fe‐N bond fractured under the attack of H2O ,then NO leaves slowly from metMbNO ,and met‐Mb was regenerated .In this experiment ,we also found that external conditions such as buffer medium ,ionic strength ,pH , temperature ,etc ,had an important influence on the coordination reaction between metMb and NO .It was favorable for the coor‐dination reaction ,when the 0.01 mol・L -1 phosphate buffer solution is near neutral condition ,the temperature is 280 K ,the co‐ordination reaction could reach equilibrium at a fastest speed .In addition ,the CD date show that NO only reacts with Fe atom in the center of heme and has less effect on the secondary structuers of protein .The research of metMb and NO played an important role to further study the function of NO .Especially the establish of equilibrium reaction mechanism between NO and heme pro‐tein has an important research value on maintaining the balance of NO in vivo and keeping the normal function in the body ’s cells .%蛋白质与配体作用的瞬时性对调节生物功能的正常发挥至关重要。采用紫外‐可见

  4. Five-coordinate [Pt(II)(bipyridine)2(phosphine)](n+) complexes: long-lived intermediates in ligand substitution reactions of [Pt(bipyridine)2](2+) with phosphine ligands.

    Lo, Warrick K C; Cavigliasso, Germán; Stranger, Robert; Crowley, James D; Blackman, Allan G


    The reaction of [Pt(N-N)2](2+) [N-N = 2,2'-bipyridine (bpy) or 4,4'-dimethyl-2,2'-bipyridine (4,4'-Me2bpy)] with phosphine ligands [PPh3 or PPh(PhSO3)2(2-)] in aqueous or methanolic solutions was studied by multinuclear ((1)H, (13)C, (31)P, and (195)Pt) NMR spectroscopy, X-ray crystallography, UV-visible spectroscopy, and high-resolution mass spectrometry. NMR spectra of solutions containing equimolar amounts of [Pt(N-N)2](2+) and phosphine ligand give evidence for rapid formation of long-lived, 5-coordinate [Pt(II)(N-N)2(phosphine)](n+) complexes. In the presence of excess phosphine ligand, these intermediates undergo much slower entry of a second phosphine ligand and loss of a bpy ligand to give [Pt(II)(N-N)(phosphine)2](n+) as the final product. The coordination of a phosphine ligand to the Pt(II) ion in the intermediate [Pt(N-N)2(phosphine)](n+) complexes is supported by the observation of (31)P-(195)Pt coupling in the (31)P NMR spectra. The 5-coordinate nature of [Pt(bpy)2{PPh(PhSO3)2}] is confirmed by X-ray crystallography. X-ray crystal structural analysis shows that the Pt(II) ion in [Pt(bpy)2{PPh(PhSO3)2}]·5.5H2O displays a distorted square pyramidal geometry, with one bpy ligand bound asymmetrically. These results provide strong support for the widely accepted associative ligand substitution mechanism for square planar Pt(II) complexes. X-ray structural characterization of the distorted square planar complex [Pt(bpy)(PPh3)2](ClO4)2 confirms this as the final product of the reaction of [Pt(bpy)2](2+) with PPh3 in CD3OD. The results of density functional calculations on [Pt(bpy)2](2+), [Pt(bpy)2(phosphine)](n+), and [Pt(bpy)(phosphine)2](n+) indicate that the bonding energy follows the trend of [Pt(bpy)(phosphine)2](n+) > [Pt(bpy)2(phosphine)](n+) > [Pt(bpy)2](2+) for stability and that the formation reactions of [Pt(bpy)2(phosphine)](n+) from [Pt(bpy)2](2+) and [Pt(bpy)(phosphine)2](n+) from [Pt(bpy)2(phosphine)](n+) are energetically favorable. These

  5. Coordination Capacity

    Cuff, Paul; Cover, Thomas


    We develop elements of a theory of cooperation and coordination in networks. Rather than considering a communication network as a means of distributing information, or of reconstructing random processes at remote nodes, we ask what dependence can be established among the nodes given the communication constraints. Specifically, in a network with communication rates between the nodes, we ask what is the set of all achievable joint distributions p(x1, ..., xm) of actions at the nodes on the network. Several networks are solved, including arbitrarily large cascade networks. Distributed cooperation can be the solution to many problems such as distributed games, distributed control, and establishing mutual information bounds on the influence of one part of a physical system on another.


    C. Delaere


    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...


    Christophe Delaere


    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  8. Preparation for Spherical particles of Praseodymium doped Perovskite Red Phosphor by Hydrothermal Reaction

    Kosaka, T.; Matsuda, A.; Mizunuma, M.; Tanaka, Y.


    Spherical particles of 0.5mol%Pr3+-doped CaTiO3 were prepared by hydrothermal reaction on dissolved CaCl2, Pr(NO3)3, and ammonium citratoperoxotitanate (IV) complex precursor solution with molar ratio of Ti/CA=1:2 and calcination in ambient atmosphere. The obtained particle exhibited red photoluminescence at 610nm. It is found that several particles have hollow structure. It is required that further investigation is needed to clarify the formation mechanism of these spherical hollow paricles.

  9. Motor coordination: a local hub for coordination.

    Calabrese, Ronald L


    A local interneuron of a crayfish central pattern generator serves as a hub that integrates ascending and descending coordinating information and passes it on to a local oscillatory microcircuit to coordinate a series of segmental appendages known as swimmerets.

  10. 氯化钙与氯化钡的二级吸附式制冷性能%Performance Study of Two-Stage Adsorption Refrigeration Cycle Based on CaCl_2/BaCl_2-NH_3 Working Pair

    胡远扬; 王丽伟; 王健; 罗伟莉; 王如竹


    To utilize low-grade heat energy below 100℃,a two-stage adsorption refrigeration cycle was proposed and adsorption performance testing unit was also established.CaCl_2 and BaCl_2 were chosen as middle-temperature salt and low-temperature salt,respectively.Cycle adsorption quantities of the adsorbents under different heating and evaporating temperatures were tested,based on which COP and SCP of the two-stage adsorption system were obtained.Results showed that the two-stage adsorption refrigeration cycle is apt for utilization of low-grade heat energy on freezing application. Cycle adsorption quantity of CaCl_2,COP and SCP of the two-stage adsorption refrigeration system are 0.490 kg/kg,0.24 and 85.6 W/kg,respectively,when heating temperature,cooling temperature and evaporating temperature are 80,30 and-20℃,respectively.%针对100℃以下温度低品位热能的利用,提出二级吸附式制冷循环,建立吸附性能测试实验台。分别以氯化钙与氯化钡作中温盐与低温盐,测试当冷却温度为30℃时,不同热源温度与不同蒸发温度条件下吸附剂的循环吸附量,并在此基础上,分析二级吸附式制冷系统的性能。研究表明,二级吸附式制冷循环能够满足全年冷冻工况的应用,并且当热源温度、冷却温度及蒸发温度分别为80℃、30℃及-20℃时,氯化钙的循环吸附量、二级吸附式制冷系统的COP与SCP分别为0.490 kg/kg,0.24与85.6 W/kg。

  11. Tuning the selectivity of Gd3N cluster endohedral metallofullerene reactions with Lewis acids.

    Stevenson, Steven; Rottinger, Khristina A; Fahim, Muska; Field, Jessica S; Martin, Benjamin R; Arvola, Kristine D


    We demonstrate the manipulation of the Lewis acid strength to selectively fractionate different types of Gd3N metallofullerenes that are present in complex mixtures. Carbon disulfide is used for all Lewis acid studies. CaCl2 exhibits the lowest reactivity but the highest selectivity by precipitating only those gadolinium metallofullerenes with the lowest first oxidation potentials. ZnCl2 selectively complexes Gd3N@C88 during the first 4 h of reaction. Reaction with ZnCl2 for an additional 7 days permits a selective precipitation of Gd3N@C84 as the dominant endohedral isolated. A third fraction is the filtrate, which possesses Gd3N@C86 and Gd3N@C80 as the two dominant metallofullerenes. The order of increasing reactivity and decreasing selectivity (left to right) is as follows: CaCl2 Lewis acids and have the highest selectivity because of their very low precipitation onsets, which are below +0.19 V (i.e., endohedrals with first oxidation potentials below +0.19 V are precipitated). For CaCl2, the precipitation threshold is estimated at a remarkably low value of +0.06 V. Because most endohedrals possess first oxidation potentials significantly higher than +0.06 V, CaCl2 is especially useful in its ability to precipitate only a select group of gadolinium metallofullerenes. The Lewis acids of intermediate reactivity (i.e., precipitation onsets estimated between +0.19 and +0.4 V) are MgCl2, MnCl2, CuCl2, and WCl4. The strongest Lewis acids (WCl6, ZrCl4, AlCl3, and FeCl3) are the least selective and tend to precipitate the entire family of gadolinium metallofullerenes. Tuning the Lewis acid for a specific type of endohedral should be useful in a nonchromatographic purification method. The ability to control which metallofullerenes are permitted to precipitate and which endohedrals would remain in solution is a key outcome of this work.

  12. Limitations of Radar Coordinates

    Bini, Donato; Lusanna, Luca; Mashhoon, Bahram


    The construction of a radar coordinate system about the world line of an observer is discussed. Radar coordinates for a hyperbolic observer as well as a uniformly rotating observer are described in detail. The utility of the notion of radar distance and the admissibility of radar coordinates are investigated. Our results provide a critical assessment of the physical significance of radar coordinates.

  13. Novel Intramolecular Coordination Chemistry of Some New Metallocene Complexes

    钱延龙; 黄吉玲


    This article summarizes the recent results of systematic study on the novel intramolecular cordination chemistry of some new substituted metallocene complexes made by our research group.It deals with the syntheses,reactions,structures of 65 new substituted metallocene complexes and some application of such coordination in homogeneous ctalysis,especially the structural chemistry of such novel intramolecular coordination complexes,and the mechanism of elimination and cyclization of such coordination compounds,as well as their control action in catalytic reactions.

  14. From Coordination Polymer to Monomeric Complex: Two Cobalt Complexes from a Single Demko-Sharpless's Tetrazole Synthesis Reaction%从配位聚合物到单分子化合物的转化:Demko-Sharpless四唑合成法制备两个新颖的Co(Ⅱ)配合物



    The reaction of CoCl2· 6H2O with 4-cyanopyridine N-oxide in the present of NaN3 affords two novel complexes, {[(POTZ)(H2O)2N3]Co(H2O)} (1) and Co(POTZ)2(H2O)4 (2) (POTZ=4-tetrazolyl pyridine N-oxide), which are two different phases yielded at different stages of a single Demko-Sharpless' tetrazole synthesis reaction.Surprisingly the 1D chain coordination polymer 1 is almost completely converted into monomeric complex 2 in this reaction, and, in a separate test, 2 also can be converted into 1. CCDC: 641222, 1; 641223, 2.

  15. Age-related Analysis of Strength, Coordination and Reaction Time of Lower Extremity in Elderly%老年人下肢肌力、协调性和反应时的年龄特征相关性

    王娜; 瓮长水; 朱才兴; 刘立明; 焦伟国; 王秋华; 郭燕梅


    Objective To study the relationship between age and lower limb neuromuscular function in elderly people under the closed chain environment. Methods 45 cases met the criteria for inclusion were divided into the 60-69 years group, 70~74 years group, and > 75 years group, 15 patients in each group. With the Functional Squat Systems (FSS), the subjects were measured isometric lower limb strength, reaction time and coordination. The maximum isometric extension strength standard value (MISS), the average isometric extension strength standard value (AISS), the overall average response time (OART), the average migration distance (AMD) were recorded. Results With the Pearson's correlation analysis, the age significantly correlated with all the other indexes (P75 years group. There was no significant difference between the 70-74 years group and >75 years group. Conclusion The lower limb neuromuscular function in elderly showed age-related significance.%目的 研究闭链动作下老年人下肢神经肌肉功能的年龄相关性.方法 45例符合人选条件的老年人分成60~69岁组、70~74岁组和≥75岁组,每组15例.应用功能性蹲屈测试系统(FSS)分别测试受试者下肢的等长肌力、反应时间和协调性.采集记录最大等长伸展肌力标准值、平均等长伸展肌力标准值、总体平均反应时间、平均偏移距离.结果 经Pearson相关分析,年龄与各项指标均有显著相关性(P<0.05~0.01);经组间方差分析,协调性在各组人群中均无显著性差异;最大肌力标准值和平均肌力标准值在60~69组均优于其他两组(P<0.05);60~69岁组的总体平均反应时间优于≥75岁组(P<0.05);70~74岁组与≥75岁组各项指标均无显著性差异(P>0.05).结论 老年人的下肢神经肌肉功能具有年龄相关性.

  16. Movement and Coordination

    ... Español Text Size Email Print Share Movement and Coordination Page Content Article Body At this age, your ... level will strengthen his body and develop his coordination. In the months ahead, your child’s running will ...

  17. Developmental coordination disorder

    ... page: // Developmental coordination disorder To use the sharing features on this page, please enable JavaScript. Developmental coordination disorder is a childhood disorder. It leads to ...

  18. Coordination and Cooperation

    Janssen, Maarten


    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can be rationalized on individualistic grounds. Finally, psychological game theory should consider how players perceive their gaming situation. ---------------------------------------------------------...

  19. Processing Coordination Ambiguity

    Engelhardt, Paul E.; Ferreira, Fernanda


    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume…

  20. Processing Coordination Ambiguity

    Engelhardt, Paul E.; Ferreira, Fernanda


    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based…

  1. Coordination and Cooperation

    M.C.W. Janssen (Maarten)


    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can

  2. Coordination and Cooperation

    M.C.W. Janssen (Maarten)


    textabstractThis comment makes four related points. First, explaining coordination is different from explaining cooperation. Second, solving the coordination problem is more important for the theory of games than solving the cooperation problem. Third, a version of the Principle of Coordination can

  3. Diazabutadienes as ligands.I. Compounds of aluminium: coordination of diazabutadienes to Al(CH3)3 and subsequent intramolecular insertion and rearrangement reactions leading to [(CH3)2Al(RNCH(CH3)C(R')=NR)] (R' = H, CH3) and (CH3)2AlRNCH2C(CH3) =NR

    Koten, G. van; Klerks, J.M.; Stufkens, D.J.; Vrieze, K.


    Reaction of R-N=CH-CH=N-R with [(CH{3}){3}Al]{2} affords the coordination product (CH{3}){3}AlRN=CH-CH=NR (A) for R = 2, 6-(CH{3}){2}C{6}H{3} and 2,4,6(CH{3}){3}C{6}H{2}. For R = 4 ClC{6}H{4}, 4-CH{3}C{6}H{4} and 4-CH{3}OC{6}H{4}, insertion takes place, giving the complexes (CH{3}){2}AlRN-CH(CH{3})-

  4. Efficient path sampling on multiple reaction channels

    van Erp, Titus S.


    Due to the time scale problem, rare events are not accessible by straight forward molecular dynamics. The presence of multiple reaction channels complicates the problem even further. The feasibility of the standard free energy based methods relies strongly on the success in finding a proper reaction coordinate. This can be very difficult task in high-dimensional complex systems and even more if several distinct reaction channels exist. Moreover, even if a proper reaction coordinate can be fou...

  5. Mechanisms that underlie coordination in children with developmental coordination disorder.

    O'Brien, Jane Clifford; Williams, Harriet G; Bundy, Anita; Lyons, Jim; Mittal, Amita


    The authors examined potential mechanisms underlying motor coordination in children with developmental coordination disorder (DCD). Because children with DCD experience difficulty processing visual, auditory, and vibrotactile information, the authors explored patterns of choice reaction time (RT) in young (6-7 years) and older (9-10 years) children with and without DCD by using a compatibility-incompatibility paradigm and different sensory modalities. Young children responded more slowly than older children to visual, auditory, and vibrotactile stimuli. Children with DCD took longer than typical children to process visual and vibrotactile stimuli under more complex stimulus-response mappings. Young children with DCD responded more slowly than typical children to visual and vibrotactile information under incompatible conditions. Children with DCD responded faster than unaffected children to auditory stimuli. The results suggest that there is a developmental nature in the processing of visual and auditory input and imply that the vibrotactile sensory modality may be key to the motor coordination difficulties of children with DCD.

  6. Enhanced time overcurrent coordination

    Enriquez, Arturo Conde; Martinez, Ernesto Vazquez [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, Apdo. Postal 114-F, Ciudad Universitaria, CP 66450 San Nicolas de los Garza, Nuevo Leon (Mexico)


    In this paper, we recommend a new coordination system for time overcurrent relays. The purpose of the coordination process is to find a time element function that allows it to operate using a constant back-up time delay, for any fault current. In this article, we describe the implementation and coordination results of time overcurrent relays, fuses and reclosers. Experiments were carried out in a laboratory test situation using signals of a power electrical system physics simulator. (author)

  7. Changes in the distribution and molecular mass of boar sperm acrosome-associated 1 proteins during the acrosome reaction; their validity as indicators for occurrence of the true acrosome reaction.

    Ogura, Yukari; Takagishi, Yuki; Harayama, Hiroshi


    The aims of this study were to investigate changes in the distribution and molecular mass of boar sperm acrosome-associated 1 (SPACA1) proteins during the acrosome reaction and to discuss validity of SPACA1 proteins as indicators for occurrence of the true acrosome reaction. Boar ejaculated spermatozoa were used for induction of the extracellular Ca(2+)-dependent acrosome reaction (true acrosome reaction) or acrosomal damages (false acrosome reaction) and then subjected to double staining with the anti-SPACA1 protein antibody and FITC-PNA and Western blotting. Extracellular Ca(2+)-dependently acrosome-reacted spermatozoa were characterized by appearance of SPACA1 proteins in the postacrosomal region (; these spermatozoa were classified into SP-3&AR pattern of double staining). However, SPACA1 proteins were not observed in the postacrosomal region of frozen-thawed spermatozoa with severely damaged acrosomes (; these spermatozoa were classified into SP-2&AR pattern). Moreover, the spermatozoa in which acrosomes were severely damaged by incubation with cyclodextrins and without CaCl2 were classified into either SP-2&AR or SP-3&AR pattern. Although SPACA1 proteins were detected mainly as 36-42kDa proteins in the spermatozoa with intact acrosomes, small types of SPACA1 proteins (15-28kDa) increased in extracellular Ca(2+)-dependently acrosome-reacted spermatozoa as well as frozen-thawed spermatozoa with damaged acrosomes. These results show the increase of boar spermatozoa classified into SP-3&AR pattern after incubation in the medium with CaCl2 and without cyclodextrins indicates occurrence of the true acrosome reaction. Moreover, we suggest the increase of small types of SPACA1 proteins is a valid indicator for occurrence of the acrosomal disintegration arising from the true and false acrosome reactions.

  8. Characterizing traits of coordination

    Poss, R.


    How can one recognize coordination languages and technologies? As this report shows, the common approach that contrasts coordination with computation is intellectually unsound: depending on the selected understanding of the word "computation", it either captures too many or too few programming

  9. Coordination models and languages

    Papadopoulos, G.A.; Arbab, F.


    A new class of models, formalisms and mechanisms has recently evolved for describing concurrent and distributed computations based on the concept of ``coordination''. The purpose of a coordination model and associated language is to provide a means of integrating a number of possibly heterogeneous c

  10. Team coordination dynamics.

    Gorman, Jamie C; Amazeen, Polemnia G; Cooke, Nancy J


    Team coordination consists of both the dynamics of team member interaction and the environmental dynamics to which a team is subjected. Focusing on dynamics, an approach is developed that contrasts with traditional aggregate-static concepts of team coordination as characterized by the shared mental model approach. A team coordination order parameter was developed to capture momentary fluctuations in coordination. Team coordination was observed in three-person uninhabited air vehicle teams across two experimental sessions. The dynamics of the order parameter were observed under changes of a team familiarity control parameter. Team members returned for the second session to either the same (Intact) or different (Mixed) team. 'Roadblock' perturbations, or novel changes in the task environment, were introduced in order to probe the stability of team coordination. Nonlinear dynamic methods revealed differences that a traditional approach did not: Intact and Mixed team coordination dynamics looked very different; Mixed teams were more stable than Intact teams and explored the space of solutions without the need for correction. Stability was positively correlated with the number of roadblock perturbations that were overcome successfully. The novel and non-intuitive contribution of a dynamical analysis was that Mixed teams, who did not have a long history working together, were more adaptive. Team coordination dynamics carries new implications for traditional problems such as training adaptive teams.

  11. Coordinate measuring machines

    De Chiffre, Leonardo

    This document is used in connection with three exercises of 2 hours duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measuring: 1) Measuring and verification of tolerances on coordinate measuring machines, 2) Traceability...

  12. Social Postural Coordination

    Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.


    The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…

  13. Social Postural Coordination

    Varlet, Manuel; Marin, Ludovic; Lagarde, Julien; Bardy, Benoit G.


    The goal of the current study was to investigate whether a visual coupling between two people can produce spontaneous interpersonal postural coordination and change their intrapersonal postural coordination involved in the control of stance. We examined the front-to-back head displacements of participants and the angular motion of their hip and…

  14. Mechanism and Experimental Observability of Global Switching Between Reactive and Nonreactive Coordinates at High Total Energies

    Teramoto, Hiroshi; Toda, Mikito; Takahashi, Masahiko; Kono, Hirohiko; Komatsuzaki, Tamiki


    We present a mechanism of global reaction coordinate switching, namely, a phenomenon in which the reaction coordinate dynamically switches to another coordinate as the total energy of the system increases. The mechanism is based on global changes in the underlying phase space geometry caused by a switching of dominant unstable modes from the original reactive mode to another nonreactive mode in systems with more than 2 degrees of freedom. We demonstrate an experimental observability to detect a reaction coordinate switching in an ionization reaction of a hydrogen atom in crossed electric and magnetic fields. For this reaction, the reaction coordinate is a coordinate along which electrons escape and its switching changes the escaping direction from the direction of the electric field to that of the magnetic field and, thus, the switching can be detected experimentally by measuring the angle-resolved momentum distribution of escaping electrons.

  15. Uranyl ion coordination

    Evans, H.T.


    A review of the known crystal structures containing the uranyl ion shows that plane-pentagon coordination is equally as prevalent as plane-square or plane-hexagon. It is suggested that puckered-hexagon configurations of OH - or H2O about the uranyl group will tend to revert to plane-pentagon coordination. The concept of pentagonal coordination is invoked for possible explanations of the complex crystallography of the natural uranyl hydroxides and the unusual behavior of polynuclear ions in hydrolyzed uranyl solutions.

  16. CaCO3, its reaction and carbonate rocks: terahertz spectroscopy investigation

    Zhan, Honglei; Wu, Shixiang; Zhao, Kun; Bao, Rima; Xiao, Lizhi


    Carbonate-rich rocks cover a primary part of the earth’s petroleum geology reservoir. The study of carbonate has special significance and more effective study methods are now needed. In order to improve the availability of carbonate rock detection, terahertz (THz) spectroscopy was employed to investigate relevant materials in Na2CO3  +  CaCl2  =  CaCO3  +  2NaCl, which is often used to generate CaCO3. By comparing the materials composited with different ions, it can be revealed that Ca2+, \\text{CO}32- , Na+ and Cl- have respective absorption features at different frequencies. Furthermore, by utilizing a conservation equation it can be observed that the average refractive indices of Na2CO3 as well as CaCl2 equal those of CaCO3 and NaCl in the entire range. Combining the absorption and refractive effect of the materials in the reaction can comprehensively characterize the different substances and reveal the inner interaction during the reaction. THz spectra can deduce the process of molecule rearrangement in the chemical reaction of long-term rock evolution. Besides, the absorption features of the real carbonate rock collected from the nearest town of Sinan county, Guizhou province in Yunnan-Guizhou plateau validate the peaks’ central frequencies of ions and the principal components of carbonates, which can be in agreement with the SEM-EDS analysis. This research will supply a spectral tool to identify the particles in the rock and deduce an evolution of petroleum carbonate reservoir.

  17. Magnetic Coordinate Systems

    Laundal, K M


    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the...

  18. Supercritical Airfoil Coordinates

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  19. Understanding social motor coordination.

    Schmidt, R C; Fitzpatrick, Paula; Caron, Robert; Mergeche, Joanna


    Recently there has been much interest in social coordination of motor movements, or as it is referred to by some researchers, joint action. This paper reviews the cognitive perspective's common coding/mirror neuron theory of joint action, describes some of its limitations and then presents the behavioral dynamics perspective as an alternative way of understanding social motor coordination. In particular, behavioral dynamics' ability to explain the temporal coordination of interacting individuals is detailed. Two experiments are then described that demonstrate how dynamical processes of synchronization are apparent in the coordination underlying everyday joint actions such as martial art exercises, hand-clapping games, and conversations. The import of this evidence is that emergent dynamic patterns such as synchronization are the behavioral order that any neural substrate supporting joint action (e.g., mirror systems) would have to sustain.

  20. Environmental Compliance Issue Coordination

    An order to establish the Department of Energy (DOE) requirements for coordination of significant environmental compliance issues to ensure timely development and consistent application of Departmental environmental policy and guidance

  1. [Coordination and donation].

    Elizalde, J; Lorente, M


    The progressive incorporation of organ transplants as a therapeutic resource resulted in organisational adaptation and overall transplant management, leading to the emergence of the figure of the transplant coordinator in the mid-1980s. In Spain, the National Organisation of Transplants (Organización Nacional de Transplantes - ONT) was created, establishing a system - called the "Spanish model" - based on a network of coordinators at three levels: national, the autonomous community and the hospital. This organisational structure is a point of reference at the world level. The prevalence of the Intensive Medicine specialisation amongst hospital transplant coordinators is remarkable. The majority of organs proceed from brain-dead patients with beating hearts and this requires the infrastructure offered by intensive care units. The functions of the coordinator can be summarised in guaranteeing a synchrony of all the elements and teams that come together in an organisational chain that has come to be called the "process of donation". Schematically, the crucial points that the hospital coordinator develops are the following: - Detection of the potential donor. - Maintenance of the donor. - Diagnosis of brain death. - Family consent. - Preparation of the hospital logistics. - Helping the relatives. - Direct involvement in the Program of Guarantee of Quality. - Person of reference in any activity related to the transplant. It would be desirable to achieve the creation of transplant coordination teams, with univocal messages, professionalism and a permanent input of the so-called "human factor", which is so necessary and also so close to the transplant world.

  2. Continuous parallel coordinates.

    Heinrich, Julian; Weiskopf, Daniel


    Typical scientific data is represented on a grid with appropriate interpolation or approximation schemes,defined on a continuous domain. The visualization of such data in parallel coordinates may reveal patterns latently contained in the data and thus can improve the understanding of multidimensional relations. In this paper, we adopt the concept of continuous scatterplots for the visualization of spatially continuous input data to derive a density model for parallel coordinates. Based on the point-line duality between scatterplots and parallel coordinates, we propose a mathematical model that maps density from a continuous scatterplot to parallel coordinates and present different algorithms for both numerical and analytical computation of the resulting density field. In addition, we show how the 2-D model can be used to successively construct continuous parallel coordinates with an arbitrary number of dimensions. Since continuous parallel coordinates interpolate data values within grid cells, a scalable and dense visualization is achieved, which will be demonstrated for typical multi-variate scientific data.

  3. Magnetic Coordinate Systems

    Laundal, K. M.; Richmond, A. D.


    Geospace phenomena such as the aurora, plasma motion, ionospheric currents and associated magnetic field disturbances are highly organized by Earth's main magnetic field. This is due to the fact that the charged particles that comprise space plasma can move almost freely along magnetic field lines, but not across them. For this reason it is sensible to present such phenomena relative to Earth's magnetic field. A large variety of magnetic coordinate systems exist, designed for different purposes and regions, ranging from the magnetopause to the ionosphere. In this paper we review the most common magnetic coordinate systems and describe how they are defined, where they are used, and how to convert between them. The definitions are presented based on the spherical harmonic expansion coefficients of the International Geomagnetic Reference Field (IGRF) and, in some of the coordinate systems, the position of the Sun which we show how to calculate from the time and date. The most detailed coordinate systems take the full IGRF into account and define magnetic latitude and longitude such that they are constant along field lines. These coordinate systems, which are useful at ionospheric altitudes, are non-orthogonal. We show how to handle vectors and vector calculus in such coordinates, and discuss how systematic errors may appear if this is not done correctly.

  4. Heterogeneous reaction of NO2 with sea salt particles


    To understand how NO2 reacts with sea salt particles in the atmosphere of Mega-cities in coastal zones,the heterogeneous reaction of NO2 on the surface of wet sea salt was investigated with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatography (IC).Kinetic measurements indicated that nitrate formation on sea salt was second order in NO 2 concentration and reactive uptake coefficients were (5.51 ± 0.19) × 10-7 and 1.26 × 10-6 respectively under 0% and 20% relative humidity (RH) at NO 2 molecular concentration of 1.96 × 1015 mol/cm3.The results showed that liquid water was formed at the site of MgCl2·6H2O,CaCl2·2H2O on the surface of sea salt and made the reaction more sustainable by releasing hydrated water and absorbing water from air even under a low RH (30%).Therefore,pure NaCl particles should not be used to represent sea salt in studies of the heterogeneous reaction with NO2.

  5. Mechanism of the reaction of the [W3S4H3(dmpe)3]+ cluster with acids: evidence for the acid-promoted substitution of coordinated hydrides and the effect of the attacking species on the kinetics of protonation of the metal-hydride bonds.

    Basallote, Manuel G; Feliz, Marta; Fernández-Trujillo, M Jesús; Llusar, Rosa; Safont, Vicent S; Uriel, Santiago


    The cluster [W(3)S(4)H(3)(dmpe)(3)](+) (1) (dmpe=1,2-bis(dimethylphosphino)ethane) reacts with HX (X=Cl, Br) to form the corresponding [W(3)S(4)X(3)(dmpe)(3)](+) (2) complexes, but no reaction is observed when 1 is treated with an excess of halide salts. Kinetic studies indicate that the hydride 1 reacts with HX in MeCN and MeCN-H(2)O mixtures to form 2 in three kinetically distinguishable steps. In the initial step, the W-H bonds are attacked by the acid to form an unstable dihydrogen species that releases H(2) and yields a coordinatively unsaturated intermediate. This intermediate adds a solvent molecule (second step) and then replaces the coordinated solvent with X(-) (third step). The kinetic results show that the first step is faster with HCl than with solvated H(+). This indicates that the rate of protonation of this metal hydride is determined not only by reorganization of the electron density at the M-H bonds but also by breakage of the H-X or H(+)-solvent bonds. It also indicates that the latter process can be more important in determining the rate of protonation.

  6. Zinc coordination spheres in protein structures.

    Laitaoja, Mikko; Valjakka, Jarkko; Jänis, Janne


    Zinc metalloproteins are one of the most abundant and structurally diverse proteins in nature. In these proteins, the Zn(II) ion possesses a multifunctional role as it stabilizes the fold of small zinc fingers, catalyzes essential reactions in enzymes of all six classes, or assists in the formation of biological oligomers. Previously, a number of database surveys have been conducted on zinc proteins to gain broader insights into their rich coordination chemistry. However, many of these surveys suffer from severe flaws and misinterpretations or are otherwise limited. To provide a more comprehensive, up-to-date picture on zinc coordination environments in proteins, zinc containing protein structures deposited in the Protein Data Bank (PDB) were analyzed in detail. A statistical analysis in terms of zinc coordinating amino acids, metal-to-ligand bond lengths, coordination number, and structural classification was performed, revealing coordination spheres from classical tetrahedral cysteine/histidine binding sites to more complex binuclear sites with carboxylated lysine residues. According to the results, coordination spheres of hundreds of crystal structures in the PDB could be misinterpreted due to symmetry-related molecules or missing electron densities for ligands. The analysis also revealed increasing average metal-to-ligand bond length as a function of crystallographic resolution, which should be taken into account when interrogating metal ion binding sites. Moreover, one-third of the zinc ions present in crystal structures are artifacts, merely aiding crystal formation and packing with no biological significance. Our analysis provides solid evidence that a minimal stable zinc coordination sphere is made up by four ligands and adopts a tetrahedral coordination geometry.

  7. Ruthenium(II) coordination chemistry of a fused donor-acceptor ligand: synthesis, characterization, and photoinduced electron-transfer reactions of [{Ru(bpy)2}(n)(TTF-ppb)](PF6)(2n) (n = 1, 2).

    Goze, Christine; Dupont, Nathalie; Beitler, Elvira; Leiggener, Claudia; Jia, Hongpeng; Monbaron, Philippe; Liu, Shi-Xia; Neels, Antonia; Hauser, Andreas; Decurtins, Silvio


    A pi-extended, redox-active bridging ligand 4',5'-bis(propylthio)tetrathiafulvenyl[i]dipyrido[2,3-a:3',2'-c]phenazine (L) was prepared via direct Schiff-base condensation of the corresponding diamine-tetrathiafulvalene (TTF) precursor with 4,7-phenanthroline-5,6-dione. Reactions of L with [Ru(bpy)(2)Cl(2)] afforded its stable mono- and dinuclear ruthenium(II) complexes 1 and 2. They have been fully characterized, and their photophysical and electrochemical properties are reported together with those of [Ru(bpy)(2)(ppb)](2+) and [Ru(bpy)(2)(mu-ppb)Ru(bpy)(2)](4+) (ppb = dipyrido[2,3-a:3',2'-c]phenazine) for comparison. In all cases, the first excited state corresponds to an intramolecular TTF --> ppb charge-transfer state. Both ruthenium(II) complexes show two strong and well-separated metal-to-ligand charge-transfer (MLCT) absorption bands, whereas the (3)MLCT luminescence is strongly quenched via electron transfer from the TTF subunit. Clearly, the transient absorption spectra illustrate the role of the TTF fragment as an electron donor, which induces a triplet intraligand charge-transfer state ((3)ILCT) with lifetimes of approximately 200 and 50 ns for mono- and dinuclear ruthenium(II) complexes, respectively.

  8. Cobalt(II) and Cobalt(III) Coordination Compounds.

    Thomas, Nicholas C.; And Others


    Presents a laboratory experiment which illustrates the formation of tris(phenanthroline)cobalt complexes in the 2+ and 3+ oxidation states, the effect of coordination on reactions of the ligand, and the use of a ligand displacement reaction in recovering the transformed ligand. Uses IR, UV-VIS, conductivity, and NMR. (MVL)

  9. Coordinating Interactions: The Event Coordination Notation

    Kindler, Ekkart

    on a much more technical level. The Event Coordination Notation (ECNO) allows modelling the behaviour of an application on a high level of abstraction that is closer to the application’s domain than to the software realizing it. Still, these models contain all necessary details for actually executing...... implementation of ECNO, which consists of a modelling environment based on Eclipse and the Eclipse Modeling Framework (EMF) and an execution engine, which fully supports all the concepts and features of ECNO discussed in this technical report. All the examples are based on EMF, but the ECNO Engine can be used......The purpose of a domain model is to concisely capture the concepts of an application’s domain, and their relation among each other. Even though the main purpose of domain models is not on implementing the application, major parts of an application can be generated from the application’s domain...

  10. Linking homogeneous and heterogeneous enantioselective catalysis through a self-assembled coordination polymer.

    García, José I; López-Sánchez, Beatriz; Mayoral, José A


    Combining the advantages of homogeneous and heterogeneous enantioselective catalysis is possible through self-supported copper coordination polymers, based on a new kind of ditopic chiral ligand bearing two azabis(oxazoline) moieties. When the coordination polymer is used to catalyze a cyclopropanation reaction, it becomes soluble in reaction conditions but precipitates after reaction completion, allowing easy recovery and efficient reuse in the same reaction up to 14 times.

  11. Quantifying linguistic coordination

    Fusaroli, Riccardo; Tylén, Kristian

    ). We employ nominal recurrence analysis (Orsucci et al 2005, Dale et al 2011) on the decision-making conversations between the participants. We report strong correlations between various indexes of recurrence and collective performance. We argue this method allows us to quantify the qualities......Language has been defined as a social coordination device (Clark 1996) enabling innovative modalities of joint action. However, the exact coordinative dynamics over time and their effects are still insufficiently investigated and quantified. Relying on the data produced in a collective decision...

  12. Introduction to Coordination Chemistry

    Lawrance, Geoffrey Alan


    Introduction to Coordination Chemistry examines and explains how metals and molecules that bind as ligands interact, and the consequences of this assembly process. This book describes the chemical and physical properties and behavior of the complex assemblies that form, and applications that may arise as a result of these properties. Coordination complexes are an important but often hidden part of our world?even part of us?and what they do is probed in this book. This book distills the essence of this topic for undergraduate students and for research scientists.

  13. Coordinate Standard Measurement Development

    Hanshaw, R.A.


    A Shelton Precision Interferometer Base, which is used for calibration of coordinate standards, was improved through hardware replacement, software geometry error correction, and reduction of vibration effects. Substantial increases in resolution and reliability, as well as reduction in sampling time, were achieved through hardware replacement; vibration effects were reduced substantially through modification of the machine component dampening and software routines; and the majority of the machine's geometry error was corrected through software geometry error correction. Because of these modifications, the uncertainty of coordinate standards calibrated on this device has been reduced dramatically.

  14. Topochemical control in desolvation of coordination polymers

    Matteo Lusi


    Reactions in the solid state are at the core of crystal engineering as they can result in new crystalline phases that are not always accessible by traditional solution methods. The work of Brammer and co-workers [Wright et al. (2015), IUCrJ, 2, 188–197] represents a clear example of this potential as applied to the synthesis of a silver–phenazine coordination polymer.

  15. Coordination failure caused by sunspots

    Beugnot, Julie; Gürgüç, Zeynep; Øvlisen, Frederik Roose


    In a coordination game with Pareto-ranked equilibria, we study whether a sunspot can lead to either coordination on an inferior equilibrium (mis-coordination) or to out-of equilibrium behavior (dis-coordination). While much of the literature searches for mechanisms to attain coordination...... on the efficient equilibrium, we consider sunspots as a potential reason for coordination failure. We conduct an experiment with a three player 2x2x2 game in which coordination on the efficient equilibrium is easy and should normally occur. In the control session, we find almost perfect coordination on the payoff......-dominant equilibrium, but in the sunspot treatment, dis-coordination is frequent. Sunspots lead to significant inefficiency, and we conclude that sunspots can indeed cause coordination failure....

  16. Coordinating Work with Groupware

    Pors, Jens Kaaber; Simonsen, Jesper


    One important goal of employing groupware is to make possible complex collaboration between geographically distributed groups. This requires a dual transformation of both technology and work practice. The challenge is to re­duce the complexity of the coordination work by successfully inte­grating...

  17. Rockin' Readers Coordinator Handbook.

    Alachua County Schools, Gainesville, FL.

    This coordinator's handbook describes the "Rockin' Readers" program, in which senior-citizen volunteers are matched with specifically targeted at-risk children (usually of kindergarten age or slightly older) in Alachua County, Florida, who tested below their peer group in language development and reading readiness skills. The handbook…

  18. Explicit Spin Coordinates

    Hunter, G; Hunter, Geoffrey; Schlifer, Ian


    The recently established existence of spherical harmonic functions, $Y_\\ell^{m}(\\theta,\\phi)$ for half-odd-integer values of $\\ell$ and $m$, allows for the introduction into quantum chemistry of explicit electron spin-coordinates; i.e. spherical polar angles $\\theta_s, \\phi_s$, that specify the orientation of the spin angular momentum vector in space. In this coordinate representation the spin angular momentum operators, $S^2, S_z$, are represented by the usual differential operators in spherical polar coordinates (commonly used for $L^2, L_z$), and their electron-spin eigenfunctions are $\\sqrt{\\sin\\theta_s} \\exp(\\pm\\phi_s/2)$. This eigenfunction representation has the pedagogical advantage over the abstract spin eigenfunctions, $\\alpha, \\beta,$ that ``integration over spin coordinates'' is a true integration (over the angles $\\theta_s, \\phi_s$). In addition they facilitate construction of many electron wavefunctions in which the electron spins are neither parallel nor antiparallel, but inclined at an interme...

  19. Equilibria with Coordination Failures

    Herings, P.J.J.; van der Laan, G.; Talman, A.J.J.


    This paper extends the recent literature on equilibria with coordination failures to arbitrary convex sets of admissible prices.We introduce a new equilibrium concept, called quantity constrained equilibrium (QCE), giving a uni.ed treatment to all cases considered in the literature so far.At a QCE

  20. Block coordination copolymers

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R


    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  1. Application of an electrochemical hydrogen meter for studying reactions in liquid sodium

    Gnanasekaran, T.; Ganesan, V.; Periaswami, G.; Mathews, C. K.; Borgstedt, H. U.


    An electrochemical hydrogen meter based on a CaCl2- CaH2 solid electrolyte was used to study the reactions of rust (FeOOH) and hydrocarbon based oil with liquid sodium in the temperature range of 623 to 748 K. The results indicated that the reaction between FeOOH and sodium is slow at 623 K and fast at 723 K. The hydrogen concentration in sodium is increased due to the reaction. Similarly, the reaction between oil and sodium proceeds slowly at 623 K whereas above 673 K, it takes place rapidly. The gaseous products released during sodium-oil reactions were analysed by means of the gas Chromatographie technique. It was found that methane was the major gaseous product formed and its formation obeyed a parabolic rate law. The response of the meter for the liberation of hydrogen in both reactions was found to be fast, qualifying the meter for detecting the ingress of hydrogen bearing compounds into sodium.

  2. Unusual metal coordination chemistry from an amino-amide derivative of 4-nitrophenol, a surprising ligand

    McGinley, John; McKee, Vickie; Toftlund, Hans


    The simple ligand N-(2-aminoethyl)-2-hydroxy-5-nitrobenzamide () exhibits several coordination modes depending on the reaction conditions, acting as a zwitterion on its own or being ionic in the presence of acid and depending on the concentration of metal present in a reaction, it can coordinate ...

  3. Global Coordinate System


    Time in hours at Oh UT is GAST (hours) = GMST + E (41) GAST in radians is GASTo (radians) = GAST (hours) L (42) The angle e required for transforming...inertial coordinates to ECEF is- 6(radians) GASTo + 6.3003880.99 (ti - th) (43) o ~ooUT Mod ( E 27) where St.i - tohLjT = (JD -2.4 106). (JDOE -2.4 x

  4. International Monetary Policy Coordination

    Carlberg, Michael


    This paper studies the international coordination of monetary policies in the world economy. It carefully discusses the process of policy competition and the structure of policy cooperation. As to policy competition, the focus is on monetary competition between Europe and America. Similarly, as to policy cooperation, the focus is on monetary cooperation between Europe and America. The spillover effects of monetary policy are negative. The policy targets are price stability and full employment.

  5. Syntheses,Structure and Oxidation Reaction of Two 1D Copper(Ⅱ)Coordination Polymers with H2O2%两个一维铜配位聚合物的合成、晶体结构及其与双氧水的氧化反应

    陈志明; 倪天军; 宫腾; 赵永梅; 朱守荣


    Two 1D copper coordination polymers,{[Cu2L(4,4′-bipy)(H2O)2]·2.5H2O}n(1)and {[Cu2L(mbix)(H2O)2]·3H2O}n(2)(H4L=N,N,N′,N′-m-xylylenediamine tetracetic acid,mbix=m-bis(imidazol-1-ylmethyl)benzene)have been synthesized for the continuance of our research work on the coordination frameworks and oxidation reaction of copper(Ⅱ)complexes with ligand L4-.Compound 1 crystallizes in monoclinic system with space group P21/c and compound 2 crystallizes in space group P(1)with triclinic system,and they both form a 1D zigig-like chain.Interchain hydrogen-bonding interactions further extend the 1D arrangement to generate a 3D supramolecular architecture for 1 and 2.UV-Vis spectra shows that compound 1 and 2 both can hydroxylate the xylyl linker in the supporting ligand L4-in spite of chemical degradation of the two compounds by reaction with H2O2.CCDC:888051,1; 888052,2.%本文利用柔性的N,N,N′,N′-间-二甲苯二胺四乙酸(H4L)及不同的氮杂环配体如刚性的4-4′-联吡啶(4,4′-bipy)及柔性的间-二(咪唑-1-亚甲基)苯(mbix)构筑了2个新的一维铜配位聚合物{[Cu2L(4,4 ′-bipy)(H2O)2]·2.5H2O}n(1)和{[Cu2L(mbix)(H2O)2]·3H2O}n(2),并对其进行了元素分析、红外光谱和X-ray单晶衍射表征.另外利用紫外-可见光谱的方法对2个化合物与H2O2的氧化反应进行了研究,结果表明虽然化合物1和2在高浓度的H2O2条件下均发生了分子断裂,但仍能使配体L4-中二甲苯基联接体C2位置发生羟基化.

  6. Global coordination: weighted voting

    Jan-Erik Lane


    Full Text Available In order to halt the depletion of global ecological capital, a number of different kinds of meetings between Governments of countries in the world has been scheduled. The need for global coordination of environmental policies has become ever more obvious, supported by more and more evidence of the running down of ecological capital. But there are no formal or binding arrangements in sight, as global environmental coordination suffers from high transaction costs (qualitative voting. The CO2 equivalent emissions, resulting in global warming, are driven by the unstoppable economic expansion in the global market economy, employing mainly fossil fuel generated energy, although at the same time lifting sharply the GDP per capita of several emerging countries. Only global environmental coordination on the successful model of the World Band and the IMF (quantitative voting can stem the rising emissions numbers and stop further environmental degradation. However, the system of weighted voting in the WB and the IMF must be reformed by reducing the excessive voting power disparities, for instance by reducing all member country votes by the cube root expression.

  7. Universal mechatronics coordinator

    Muir, Patrick F.


    Mechatronic systems incorporate multiple actuators and sensor which must be properly coordinated to achieve the desired system functionality. Many mechatronic systems are designed as one-of-a-kind custom projects without consideration for facilitating future system or alterations and extensions to the current syste. Thus, subsequent changes to the system are slow, different, and costly. It has become apparent that manufacturing processes, and thus the mechatronics which embody them, need to be agile in order to more quickly and easily respond to changing customer demands or market pressures. To achieve agility, both the hardware and software of the system need to be designed such that the creation of new system and the alteration and extension of current system is fast and easy. This paper describes the design of a Universal Mechatronics Coordinator (UMC) which facilitates agile setup and changeover of coordination software for mechatronic systems. The UMC is capable of sequencing continuous and discrete actions that are programmed as stimulus-response pairs, as state machines, or a combination of the two. It facilitates the modular, reusable programing of continuous actions such as servo control algorithms, data collection code, and safety checking routines; and discrete actions such as reporting achieved states, and turning on/off binary devices. The UMC has been applied to the control of a z- theta assembly robot for the Minifactory project and is applicable to a spectrum of widely differing mechatronic systems.

  8. Improving Project Manufacturing Coordination

    Korpivaara Ville


    Full Text Available The objective of this research is to develop firms’ project manufacturing coordination. The development will be made by centralizing the manufacturing information flows in one system. To be able to centralize information, a deep user need assessment is required. After user needs have been identified, the existing system will be developed to match these needs. The theoretical background is achieved through exploring the literature of project manufacturing, development project success factors and different frameworks and tools for development project execution. The focus of this research is rather in customer need assessment than in system’s technical expertise. To ensure the deep understanding of customer needs this study is executed by action research method. As a result of this research the information system for project manufacturing coordination was developed to respond revealed needs of the stakeholders. The new system improves the quality of the manufacturing information, eliminates waste in manufacturing coordination processes and offers a better visibility to the project manufacturing. Hence it provides a solid base for the further development of project manufacturing.

  9. Adaptive group coordination and role differentiation.

    Michael E Roberts

    Full Text Available Many real world situations (potluck dinners, academic departments, sports teams, corporate divisions, committees, seminar classes, etc. involve actors adjusting their contributions in order to achieve a mutually satisfactory group goal, a win-win result. However, the majority of human group research has involved situations where groups perform poorly because task constraints promote either individual maximization behavior or diffusion of responsibility, and even successful tasks generally involve the propagation of one correct solution through a group. Here we introduce a group task that requires complementary actions among participants in order to reach a shared goal. Without communication, group members submit numbers in an attempt to collectively sum to a randomly selected target number. After receiving group feedback, members adjust their submitted numbers until the target number is reached. For all groups, performance improves with task experience, and group reactivity decreases over rounds. Our empirical results provide evidence for adaptive coordination in human groups, and as the coordination costs increase with group size, large groups adapt through spontaneous role differentiation and self-consistency among members. We suggest several agent-based models with different rules for agent reactions, and we show that the empirical results are best fit by a flexible, adaptive agent strategy in which agents decrease their reactions when the group feedback changes. The task offers a simple experimental platform for studying the general problem of group coordination while maximizing group returns, and we distinguish the task from several games in behavioral game theory.

  10. Symmetric two-coordinate photodiode

    Dobrovolskiy Yu. G.


    Full Text Available The two-coordinate photodiode is developed and explored on the longitudinal photoeffect, which allows to get the coordinate descriptions symmetric on the steepness and longitudinal resistance great exactness. It was shown, that the best type of the coordinate description is observed in the case of scanning by the optical probe on the central part of the photosensitive element. The ways of improvement of steepness and linear of its coordinate description were analyzed.

  11. Invariant Manifolds and Collective Coordinates

    Papenbrock, T


    We introduce suitable coordinate systems for interacting many-body systems with invariant manifolds. These are Cartesian in coordinate and momentum space and chosen such that several components are identically zero for motion on the invariant manifold. In this sense these coordinates are collective. We make a connection to Zickendraht's collective coordinates and present certain configurations of few-body systems where rotations and vibrations decouple from single-particle motion. These configurations do not depend on details of the interaction.

  12. (E) Enol ethers from the stereoselective reduction of α-alkoxy-β-ketophosphonates and Wittig type reaction

    DAYOUB; Wissam; DOUTHEAU; Alain


    When α-alkoxy-β-ketophosphonates,prepared by the Rh(Ⅱ) mediated insertion reaction of α-diazo-β-ketophosphonates into the OH bond of primary alcohols,were reduced either by NaBH4 in the presence of CaCl2 or by DIBAL,they respectively gave the corresponding anti or syn stereomeric hydroxyphosphonates with pronounced to complete stereoselectivity.Submitted to the action of potassium tert-butoxyde,syn isomers led to the corresponding pure(E) enol ethers in moderate to good yields.Under the same conditions anti isomers led to a mixture of(Z) and(E) enol ethers in rather poor yields.The sequence was applied to the preparation of some allyl-vinyl ethers with a(E) configuration for the vinylic double bond.

  13. Coordination Processes in International Organisations

    Nedergaard, Peter


    to coordinate relatively elaborate agreements due to the strength of its coordination as far as professional or technical and political activities (excepting the ILO budget) are concerned. In other more clear-cut or 'simple' policy areas such as the ILO budget, the EU coordination is weak: this contrast...

  14. Orbital Energy-Based Reaction Analysis of SN2 Reactions

    Takao Tsuneda


    Full Text Available An orbital energy-based reaction analysis theory is presented as an extension of the orbital-based conceptual density functional theory. In the orbital energy-based theory, the orbitals contributing to reactions are interpreted to be valence orbitals giving the largest orbital energy variation from reactants to products. Reactions are taken to be electron transfer-driven when they provide small variations for the gaps between the contributing occupied and unoccupied orbital energies on the intrinsic reaction coordinates in the initial processes. The orbital energy-based theory is then applied to the calculations of several S N2 reactions. Using a reaction path search method, the Cl− + CH3I → ClCH3 + I− reaction, for which another reaction path called “roundabout path” is proposed, is found to have a precursor process similar to the roundabout path just before this SN2 reaction process. The orbital energy-based theory indicates that this precursor process is obviously driven by structural change, while the successor SN2 reaction proceeds through electron transfer between the contributing orbitals. Comparing the calculated results of the SN2 reactions in gas phase and in aqueous solution shows that the contributing orbitals significantly depend on solvent effects and these orbitals can be correctly determined by this theory.

  15. Work Coordination Engine

    Zendejas, Silvino; Bui, Tung; Bui, Bach; Malhotra, Shantanu; Chen, Fannie; Kim, Rachel; Allen, Christopher; Luong, Ivy; Chang, George; Sadaqathulla, Syed


    The Work Coordination Engine (WCE) is a Java application integrated into the Service Management Database (SMDB), which coordinates the dispatching and monitoring of a work order system. WCE de-queues work orders from SMDB and orchestrates the dispatching of work to a registered set of software worker applications distributed over a set of local, or remote, heterogeneous computing systems. WCE monitors the execution of work orders once dispatched, and accepts the results of the work order by storing to the SMDB persistent store. The software leverages the use of a relational database, Java Messaging System (JMS), and Web Services using Simple Object Access Protocol (SOAP) technologies to implement an efficient work-order dispatching mechanism capable of coordinating the work of multiple computer servers on various platforms working concurrently on different, or similar, types of data or algorithmic processing. Existing (legacy) applications can be wrapped with a proxy object so that no changes to the application are needed to make them available for integration into the work order system as "workers." WCE automatically reschedules work orders that fail to be executed by one server to a different server if available. From initiation to completion, the system manages the execution state of work orders and workers via a well-defined set of events, states, and actions. It allows for configurable work-order execution timeouts by work-order type. This innovation eliminates a current processing bottleneck by providing a highly scalable, distributed work-order system used to quickly generate products needed by the Deep Space Network (DSN) to support space flight operations. WCE is driven by asynchronous messages delivered via JMS indicating the availability of new work or workers. It runs completely unattended in support of the lights-out operations concept in the DSN.

  16. The Spectroscopy and Reaction Kinetics of Coordinated Unsaturated Metal Carbonyls.


    liquid disso- ciation. I. Martyn Poliakoff and Eric Weitz, to be published in "Advances in Organo- metallic Chemistry" (1985). 2. A. J. Ouderkirk, P... Poliakoff and Eric Weitz, to be published in Annual Review of Organometallic Chemistry, 1985. c) Gas Phase Infrared Spectroscopy and Recombination of this work by the 7.. 7 donors of the Petroleum Research Fund, administered by the American Chemical * -Society. We thank Dr. Martyn Poliakoff

  17. The Spectroscopy and Reaction Kinetics of Coordinatively Unsaturated Metal Carbonyls.


    and Eric Weitz, J. Am. Chem. Soc. 105, 3354 (1983). 3. A. Ouderkirk and Eric Weitz, J. Chem. Phys. Z2, 1089 (1983). 4. M. Poliakoff and E. Weitz...Advances in Organometallic Chemistry 25, 277 V (1986). 5. Eric Weitz, J. Phys. Chem. 21, 3945 (1987). 6. Martyn Poliakoff and Eric Weitz, Accts. Chem. Res...Nazran, A. S.; Drouin, K.; Hackett, P. A. J. Phys. Chem, 1986, 90, 2982. 11. Barton, T. J.; Grinter, R.; Thomson, A. J.; Davies, B.; Poliakoff , M. J. C. S

  18. Advice for Coordination

    Hankin, Chris; Nielson, Flemming; Nielson, Hanne Riis


    demanding than the closed joinpoints in more traditional aspect oriented languages like AspectJ. The usefulness of our approach is demonstrated by mechanisms for discretionary and mandatory access control policies, as usually expressed by reference monitors, as well as mechanisms for logging actions.......We show how to extend a coordination language with support for aspect oriented programming. The main challenge is how to properly deal with the trapping of actions before the actual data have been bound to the formal parameters. This necessitates dealing with open joinpoints – which is more...

  19. Markov stochasticity coordinates

    Eliazar, Iddo


    Markov dynamics constitute one of the most fundamental models of random motion between the states of a system of interest. Markov dynamics have diverse applications in many fields of science and engineering, and are particularly applicable in the context of random motion in networks. In this paper we present a two-dimensional gauging method of the randomness of Markov dynamics. The method-termed Markov Stochasticity Coordinates-is established, discussed, and exemplified. Also, the method is tweaked to quantify the stochasticity of the first-passage-times of Markov dynamics, and the socioeconomic equality and mobility in human societies.

  20. Gold coordination during homogeneous alkyne and allene cyclisation catalysis: Coordination to substrates, to ancillary ligands and in intermediates

    Hubert Schmidbaur


    Full Text Available The ever-increasing role of homogeneous gold catalysis in organic synthesis and the consequent need to be able to rationally control the rate and outcome of such reactions has emphasised the importance of each successive metal–carbon coordination step. Concentrating on alkyne and allene cyclisation and upon reaction mechanisms postulated on the basis of empirical and theoretical results, we have examined the coordination of gold fragments to triple bonds, the modification of gold(I precatalysts to effect specific reaction pathways or enantioselectivity and the isolation of coordinated intermediates or model compounds thereof. Some of the recent advances that have been made in various laboratories are described in this compact review.

  1. An end-on-coordinated As4 tetrahedron.

    Schwarzmaier, Christoph; Timoshkin, Alexey Y; Scheer, Manfred


    One time only: The reaction of [Cp*Ru(dppe)Cl] with the potent As4 transfer reagent [Ag(η(2)-As4)2](+)[pftb](-) leads to [Cp*Ru(dppe)(η(1)-As4)](+)[pftb](-) with an unprecedented end-on-coordinated As4 tetrahedron. Reaction with a second cationic ruthenium complex fragment does not lead to a second end-on coordination but to the cleavage of one basal As-As bond. This behavior, which differs from its phosphorus analogues, is rationalized by DFT calculations.

  2. Non covalent assembly of coordination superstructures

    Khlobystov, A N


    The main topic of this work is the design of discrete and polymeric multi-component coordination structures using non-covalent interactions between organic and inorganic molecular components. All of the structures described herein are based on transition metal cations and N-donor heterocyclic bis-exodentate ligands with different geometries and various spacer functionalities. The predominant method used for the structural characterisation of the complexes was single crystal X-ray crystallography. X-ray powder diffraction, IR and NMR spectroscopies and TEM and AFM imaging were used to characterise the bulk products from the reactions. Chapter 1 is a comparative review of non-covalent interactions relevant to coordination superstructures and covers the latest developments in the area of crystal engineering and supramolecular chemistry. The nature, geometry and relative energy of the non-covalent interactions are considered in detail in order to reveal their influence on the structure and properties of complexes...

  3. Coordination Processes in International Organisations

    Nedergaard, Peter


    The EU is not a member of the International Labour Organisation (ILO), but relatively elaborate EU coordination takes place anyway. This paper addresses two research questions: 1) How is it possible to evaluate the coordination of the EU in its specific observable configuration in the ILO?, and 2......) To what outcome does this coordination lead and why? Based on an analysis of EU coordination before and during the International Labour Conference in 2005, and on a comparison with coordination processes of the IMEC group, it is found that the Commission and the Presidency act as twin-agents vis...... by the principals. On the other hand, both before and during the Conference, the Member States accept the so-called discursive coordination of the Commission, which seems to be of great (but often neglected) importance. Owing to the organisational set-up in which coordination takes place, the EU is able...

  4. 中西药雾化吸入配合护理防治鼻咽癌放疗口腔不良反应30例%Atomization Inhalation of Combined Chinese and Western Drugs Coordinated by Nursing for Prevent-ing and Treating Oral Adverse Reactions after Nasopharyngeal Carcinoma Radiotherapy in 30 Cases



    Objective To observe the clinical effect of atomization inhalation of self-designed Qingreyangying Decoction and Vitamin C Injection coordinated by the nursing care for preventing and treating oral adverse reactions caused by radiotherapy in the patients with nasopharyngeal carcinoma(NPC). Methods 60 patients with NPC in the hospital from January 2012 to October 2012 were selected and randomly divided into the observation group and the control group,30 cases in each group. All the patients were given the comprehen-sive symptomatic treatment of anti-infection,analgesia,nutrition support,etc. ,and routine care,but the observation group was added with the atomization inhalation of self-designed Qingreyangying Decoction and Vitamin C Injection,and corresponding nursing process. Results The number of the patients appearing more than grade Ⅱof acute adverse reactions such as dry mouth,taste sense change,dys-phagia,oropharyngeal pain and oral mucosa reaction in the observation group was lower than that in the control group( P < 0. 05);the appearance of radiotherapeutical adverse reactions in the observation group was later than that in the control group,while the recovery in the observation group was faster than that in the control group and the survival quality was superior to the control group ( P < 0. 05);no adverse reactions related with self-designed Qingreyangying Decoction and Vitamin C Injection in the observation group occurred,the occurrence rates of adverse reactions in the radiotherapy and chemotherapy in the observation group were similar to those in the control group without statistical differences( P ? 0. 05). Conclusion Atomization inhalation of self-designed Qingre Yangyin Decoction and Vitamin C Injection coordinated by the nursing care for preventing and treating the radiotherapeutical complica-tions in the patients with NPC,slows down the response time,lightens the degree of oral mucosa reaction,improves the survival quality, has high safety and is

  5. Solvent effect in the Walden inversion reactions

    Jaume, J.; Lluch, J. M.; Oliva, A.; Bertrán, J.


    The solvent effect on the fluoride exchange reaction has been studied by means of ab initio calculations using the 3-21G basis set. It is shown that the motion of the solvent molecules is an important part of the reaction coordinate.

  6. Moving attractive virtual agent improves interpersonal coordination stability.

    Zhao, Zhong; Salesse, Robin N; Gueugnon, Mathieu; Schmidt, Richard C; Marin, Ludovic; Bardy, Benoît G


    Interpersonal motor coordination is influenced not only by biomechanical factors such as coordination pattern, oscillating frequency, and individual differences, but also by psychosocial factor such as likability and social competences. Based on the social stereotype of "what is beautiful is good", the present study aimed at investigating whether people coordinate differently with physically attractive people compared to less attractive people. 34 participants were engaged in an interpersonal coordination task with different looking (virtual) agents while performing at the same time a reaction time task. Results showed that participants had more stable motor coordination with the moving attractive than with the less attractive agent, and that the difference in motor coordination could not be interpreted by a specific attention allocation strategy. Our findings provide the evidence that physical attractiveness genuinely affects how people interact with another person, and that the temporal-spatial coordinated movement varies with the partner's psychosocial characteristics. The study broadens the perspective of exploring the effect of additional psychosocial factors on social motor coordination.

  7. Calculation of turbulent reactive flows in general orthogonal coordinates

    Lai, M. K. Y.


    The mathematical and numerical methodology for an extended and enhanced version of the TURCOM computer code, called TURCOM-BFC, is presented. This code solves the conservation equations of multi-component chemically reactive and turbulent flows in general curvilinear orthogonal coordinates. The k-epsilon turbulence submodel is used. Flame chemistry assumes a number of species and chemical reactions. The latter are subdivided into finite-rate reaction steps and a one-step irreversible reaction, whose rate is controlled by a combination of mixing and global kinetics. Both the SIMPLE and PISO algorithms are implemented to solve the system of equations. The capability of TURCOM-BFC is tested and demonstrated by predicting 3-dimensional combustion flow inside a reaction furnace, where both polar-cylindrical and bipolar coordinates are used.

  8. Reaction Graph



    The paper proposes reaction graphs as graphical representations of computational objects.A reaction graph is a directed graph with all its arrows and some of its nodes labeled.Computations are modled by graph rewriting of a simple nature.The basic rewriting rules embody the essence of both the communications among processes and cut-eliminations in proofs.Calculi of graphs are ideentified to give a formal and algebraic account of reaction graphs in the spirit of process algebra.With the help of the calculi,it is demonstrated that reaction graphs capture many interesting aspects of computations.

  9. Coordination using Implicit Communication

    Cuff, Paul


    We explore a basic noise-free signaling scenario where coordination and communication are naturally merged. A random signal X_1,...,X_n is processed to produce a control signal or action sequence A_1,...,A_n, which is observed and further processed (without access to X_1,...,X_n) to produce a third sequence B_1,...,B_n. The object of interest is the set of empirical joint distributions p(x,a,b) that can be achieved in this setting. We show that H(A) >= I(X;A,B) is the necessary and sufficient condition for achieving p(x,a,b) when no causality constraints are enforced on the encoders. We also give results for various causality constraints. This setting sheds light on the embedding of digital information in analog signals, a concept that is exploited in digital watermarking, steganography, cooperative communication, and strategic play in team games such as bridge.

  10. On Coordinating Collaborative Objects

    Imine, Abdessamad


    A collaborative object represents a data type (such as a text document) designed to be shared by a group of dispersed users. The Operational Transformation (OT) is a coordination approach used for supporting optimistic replication for these objects. It allows the users to concurrently update the shared data and exchange their updates in any order since the convergence of all replicas, i.e. the fact that all users view the same data, is ensured in all cases. However, designing algorithms for achieving convergence with the OT approach is a critical and challenging issue. In this paper, we propose a formal compositional method for specifying complex collaborative objects. The most important feature of our method is that designing an OT algorithm for the composed collaborative object can be done by reusing the OT algorithms of component collaborative objects. By using our method, we can start from correct small collaborative objects which are relatively easy to handle and incrementally combine them to build more ...

  11. Coordinating Group report


    In December 1992, western governors and four federal agencies established a Federal Advisory Committee to Develop On-site Innovative Technologies for Environmental Restoration and Waste Management (the DOIT Committee). The purpose of the Committee is to advise the federal government on ways to improve waste cleanup technology development and the cleanup of federal sites in the West. The Committee directed in January 1993 that information be collected from a wide range of potential stakeholders and that innovative technology candidate projects be identified, organized, set in motion, and evaluated to test new partnerships, regulatory approaches, and technologies which will lead to improve site cleanup. Five working groups were organized, one to develop broad project selection and evaluation criteria and four to focus on specific contaminant problems. A Coordinating Group comprised of working group spokesmen and federal and state representatives, was set up to plan and organize the routine functioning of these working groups. The working groups were charged with defining particular contaminant problems; identifying shortcomings in technology development, stakeholder involvement, regulatory review, and commercialization which impede the resolution of these problems; and identifying candidate sites or technologies which could serve as regional innovative demonstration projects to test new approaches to overcome the shortcomings. This report from the Coordinating Group to the DOIT Committee highlights the key findings and opportunities uncovered by these fact-finding working groups. It provides a basis from which recommendations from the DOIT Committee to the federal government can be made. It also includes observations from two public roundtables, one on commercialization and another on regulatory and institutional barriers impeding technology development and cleanup.

  12. Chemical potential and reaction electronic flux in symmetry controlled reactions.

    Vogt-Geisse, Stefan; Toro-Labbé, Alejandro


    In symmetry controlled reactions, orbital degeneracies among orbitals of different symmetries can occur along a reaction coordinate. In such case Koopmans' theorem and the finite difference approximation provide a chemical potential profile with nondifferentiable points. This results in an ill-defined reaction electronic flux (REF) profile, since it is defined as the derivative of the chemical potential with respect to the reaction coordinate. To overcome this deficiency, we propose a new way for the calculation of the chemical potential based on a many orbital approach, suitable for reactions in which symmetry is preserved. This new approach gives rise to a new descriptor: symmetry adapted chemical potential (SA-CP), which is the chemical potential corresponding to a given irreducible representation of a symmetry group. A corresponding symmetry adapted reaction electronic flux (SA-REF) is also obtained. Using this approach smooth chemical potential profiles and well defined REFs are achieved. An application of SA-CP and SA-REF is presented by studying the Cs enol-keto tautomerization of thioformic acid. Two SA-REFs are obtained, JA'(ξ) and JA'' (ξ). It is found that the tautomerization proceeds via an in-plane delocalized 3-center 4-electron O-H-S hypervalent bond which is predicted to exist only in the transition state (TS) region. © 2016 Wiley Periodicals, Inc.

  13. A Unified Theory of Chemical Reactions

    Aubry, S


    We propose a new and general formalism for elementary chemical reactions where quantum electronic variables are used as reaction coordinates. This formalism is in principle applicable to all kinds of chemical reactions ionic or covalent. Our theory reveals the existence of an intermediate situation between ionic and covalent which may be almost barrierless and isoenegetic and which should be of high interest for understanding biochemistry.

  14. Invariant manifolds and collective coordinates

    Papenbrock, T. [Centro Internacional de Ciencias, Cuernavaca, Morelos (Mexico); Institute for Nuclear Theory, University of Washington, Seattle, WA (United States); Seligman, T.H. [Centro Internacional de Ciencias, Cuernavaca, Morelos (Mexico); Centro de Ciencias Fisicas, University of Mexico (UNAM), Cuernavaca (Mexico)


    We introduce suitable coordinate systems for interacting many-body systems with invariant manifolds. These are Cartesian in coordinate and momentum space and chosen such that several components are identically zero for motion on the invariant manifold. In this sense these coordinates are collective. We make a connection to Zickendraht's collective coordinates and present certain configurations of few-body systems where rotations and vibrations decouple from single-particle motion. These configurations do not depend on details of the interaction. (author)

  15. Expanding coordination chemistry from protein to protein assembly.

    Sanghamitra, Nusrat J M; Ueno, Takafumi


    Bioinorganic chemistry is of growing importance in the fields of nanomaterial science and biotechnology. Coordination of metals by biological systems is a crucial step in intricate enzymatic reactions such as photosynthesis, nitrogen fixation and biomineralization. Although such systems employ protein assemblies as molecular scaffolds, the important roles of protein assemblies in coordination chemistry have not been systematically investigated and characterized. Many researchers are joining the field of bioinorganic chemistry to investigate the inorganic chemistry of protein assemblies. This area is emerging as an important next-generation research field in bioinorganic chemistry. This article reviews recent progress in rational design of protein assemblies in coordination chemistry for integration of catalytic reactions using metal complexes, preparation of mineral biomimetics, and mechanistic investigations of biomineralization processes with protein assemblies. The unique chemical properties of protein assemblies in the form of cages, tubes, and crystals are described in this review.

  16. Intact Procedural Motor Sequence Learning in Developmental Coordination Disorder

    Lejeune, Caroline; Catale, Corinne; Willems, Sylvie; Meulemans, Thierry


    The purpose of the present study was to explore the possibility of a procedural learning deficit among children with developmental coordination disorder (DCD). We tested 34 children aged 6-12 years with and without DCD using the serial reaction time task, in which the standard keyboard was replaced by a touch screen in order to minimize the impact…

  17. A one-dimensional barium(II) coordination polymer with a coordinated nitro group of 2-nitrobenzoate

    Bikshandarkoil R Srinivasan; Santosh Y Shetgaonkar; Pallepogu Raghavaiah


    The aqueous reaction of barium carbonate with 2-nitrobenzoic acid (2-nbaH) results in the formation of a one-dimensional coordination polymer, catena-poly[[hexa(aqua)dibarium(II)]bis[(2-2-nitrobenzoate-O,O,O-NO2)(2-2-nitrobenzoate-O,O,O')

  18. Coordination Control Of Complex Machines

    J.C.M. Baeten; B. van Beek; J. Markovski; L.J.A.M. Somers


    Control and coordination are important aspects of the development of complex machines due to an ever-increasing demand for better functionality, quality, and performance. In WP6 of the C4C project, we developed a synthesis-centric systems engineering framework suitable for supervisory coordination o

  19. Coordinate-Free Rotation Operator.

    Leubner, C.


    Suggests the use of a coordinate-free rotation operator for the teaching of rotations in Euclidean three space because of its twofold didactic advantage. Illustrates the potentialities of the coordinate-free rotation operator approach by a number of examples. (Author/GA)

  20. Coordination of Conditional Poisson Samples

    Grafström Anton


    Full Text Available Sample coordination seeks to maximize or to minimize the overlap of two or more samples. The former is known as positive coordination, and the latter as negative coordination. Positive coordination is mainly used for estimation purposes and to reduce data collection costs. Negative coordination is mainly performed to diminish the response burden of the sampled units. Poisson sampling design with permanent random numbers provides an optimum coordination degree of two or more samples. The size of a Poisson sample is, however, random. Conditional Poisson (CP sampling is a modification of the classical Poisson sampling that produces a fixed-size πps sample. We introduce two methods to coordinate Conditional Poisson samples over time or simultaneously. The first one uses permanent random numbers and the list-sequential implementation of CP sampling. The second method uses a CP sample in the first selection and provides an approximate one in the second selection because the prescribed inclusion probabilities are not respected exactly. The methods are evaluated using the size of the expected sample overlap, and are compared with their competitors using Monte Carlo simulation. The new methods provide a good coordination degree of two samples, close to the performance of Poisson sampling with permanent random numbers.

  1. Investigating silver coordination to mixed chalcogen ligands.

    Knight, Fergus R; Randall, Rebecca A M; Wakefield, Lucy; Slawin, Alexandra M Z; Woollins, J Derek


    Six silver(I) coordination complexes have been prepared and structurally characterised. Mixed chalcogen-donor acenaphthene ligands L1-L3 [Acenap(EPh)(E'Ph)] (Acenap = acenaphthene-5,6-diyl; E/E' = S, Se, Te) were independently treated with silver(I) salts (AgBF₄/AgOTf). In order to keep the number of variables to a minimum, all reactions were carried out using a 1:1 ratio of Ag/L and run in dichloromethane. The nature of the donor atoms, the coordinating ability of the respective counter-anion and the type of solvent used in recrystallisation, all affect the structural architecture of the final silver(I) complex, generating monomeric, silver(I) complexes {[AgBF₄(L)₂] (1 L = L1; 2 L = L2; 3 L = L3), [AgOTf(L)₃] (4 L = L1; 5 L = L3), [AgBF₄(L)₃] (2a L = L1; 3a L = L3)} and a 1D polymeric chain {[AgOTf(L3)](n) 6}. The organic acenaphthene ligands L1-L3 adopt a number of ligation modes (bis-monodentate μ₂-η²-bridging, quasi-chelating combining monodentate and η⁶-E(phenyl)-Ag(I) and classical monodentate coordination) with the central silver atom at the centre of a tetrahedral or trigonal planar coordination geometry in each case. The importance of weak interactions in the formation of metal-organic structures is also highlighted by the number of short non-covalent contacts present within each complex.

  2. Investigating Silver Coordination to Mixed Chalcogen Ligands

    J. Derek Woollins


    Full Text Available Six silver(I coordination complexes have been prepared and structurally characterised. Mixed chalcogen-donor acenaphthene ligands L1–L3 [Acenap(EPh(E'Ph] (Acenap = acenaphthene-5,6-diyl; E/E' = S, Se, Te were independently treated with silver(I salts (AgBF4/AgOTf. In order to keep the number of variables to a minimum, all reactions were carried out using a 1:1 ratio of Ag/L and run in dichloromethane. The nature of the donor atoms, the coordinating ability of the respective counter-anion and the type of solvent used in recrystallisation, all affect the structural architecture of the final silver(I complex, generating monomeric, silver(I complexes {[AgBF4(L2] (1 L = L1; 2 L = L2; 3 L = L3, [AgOTf(L3] (4 L = L1; 5 L = L3, [AgBF4(L3] (2a L = L1; 3a L = L3} and a 1D polymeric chain {[AgOTf(L3]n 6}. The organic acenaphthene ligands L1-L3 adopt a number of ligation modes (bis-monodentate μ2-η2-bridging, quasi-chelating combining monodentate and η6-E(phenyl-Ag(I and classical monodentate coordination with the central silver atom at the centre of a tetrahedral or trigonal planar coordination geometry in each case. The importance of weak interactions in the formation of metal-organic structures is also highlighted by the number of short non-covalent contacts present within each complex.

  3. Comparative Reaction Diagrams for the SN2 Reaction Formulated According to the Leffler Analysis and the Hammond Postulate.

    Haddon, Robert C; Tian, Ziqi; Jiang, De-En


    The Hammond Postulate and the Leffler analysis have provided a cornerstone in the understanding of reaction processes in organic chemistry for over 60 years, yet quantitative applications of these methodologies over the range of reactions envisaged in the original works remain elusive. In the present paper, we analyze a series of SN2 reactions in three solvents that lead to endothermic and exothermic reaction processes, and we show that within the hybridization reaction coordinate the SN2 reaction is fully consistent with both treatments. We give new presentations of the reaction energies as a function of reaction progress, which allow the generation of unified reaction coordinate diagrams that show a linear relationship between the hybridization metric of reaction progress and the relative energies of the stationary points on the potential surface as a function of structure and solvent as originally envisaged by Leffler and Hammond.

  4. Enterprise Coordination on the Internet

    Charles Petrie


    Full Text Available Enterprises are now connected internally and externally to other Enterprises via the Internet in ways that are increasingly difficult to manage, especially as these interconnections become more dynamic. Current methods of coordinating the effects of change as they propagate through these networks of connections are not likely to scale. What is needed is a new paradigm for how the Internet supports such coordination. Indeed, the Internet should and could provide fundamental coordination functions that are missing today. In this paper, we describe how such a “Coordinated Internet” would work (this paper is an expanded version of [1]. The key functionality of a Coordinated Internet would be that the Internet actively watches what people do (analogous to search completion on desktops today, correlates these activities, and actively notifies people when and how their current tasks affect and are affected by the activities of other people. This would be accomplished by standard coordination functions implemented as a common Internet layer that can be used as a utility by more specialized applications. Such a Coordinated Internet would revolutionize enterprise management, for all enterprises, large and small, corporate and personal. For example, static workflows would become obsolete for all but the the most routine processes. Some solutions provide existence proofs of such a coordination substrate, such as the Redux solution in concurrent engineering, which we describe herein. However, foundational research remains to be done in the new field of Coordination Engineering in order to reach the goal of a future Internet in which coordination functions are fundamental.

  5. Differential changes in the development of motor coordination and executive functions in children with motor coordination impairments.

    Michel, Eva; Molitor, Sabine; Schneider, Wolfgang


    Cognitive and motor coordination skills of children with and without motor coordination impairments were examined with a one-year follow-up investigation. Initially, children were between 4 and 6 years old. Age-appropriate tests of executive functions (updating, switching, inhibition, interference control), motor coordination (the Movement Assessment Battery for Children-2) and fitness (the Körperkoordinations-Test für Kinder) were administered in two consecutive years. Several background variables (age, socioeconomic status, medical support, clinical interventions, leisure activities) and potential moderators (nonverbal intelligence, reaction time, visual perception) were controlled. The matched sample consisted of 48 control children and 48 children with motor coordination impairments. The children's executive functions dramatically improved during the one-year period. With regard to motor coordination performance, half of the impaired children caught up to the control children's level ("remission group"), while the remaining half showed no improvement ("persisting group"). Compared to the persisting group, the children in the remission group showed markedly better interference control at both measurement points. The correlation between executive functions and motor coordination is significant in the persisting group, but not in the remission group. The results of the study are discussed in the light of the role of executive functions, especially inhibition processes, for the automatization of motor coordination tasks.

  6. Keep Meaning in Conversational Coordination

    Elena Clare Cuffari


    Full Text Available Coordination is a widely employed term across recent quantitative and qualitative approaches to intersubjectivity, particularly approaches that give embodiment and enaction central explanatory roles. With a focus on linguistic and bodily coordination in conversational contexts, I review the operational meaning of coordination in recent empirical research and related theorizing of embodied intersubjectivity. This discussion articulates what must be involved in treating linguistic meaning as dynamic processes of coordination. The coordination approach presents languaging as a set of dynamic self-organizing processes and actions on multiple timescales and across multiple modalities that come about and work in certain domains (those jointly constructed in social, interactive, high-order sense-making. These processes go beyond meaning at the level that is available to first-person experience. I take one crucial consequence of this to be the ubiquitously moral nature of languaging with others. Languaging coordinates experience, among other levels of behavior and event. Ethical effort is called for by the automatic autonomy-influencing forces of languaging as coordination.

  7. Chinese geodetic coordinate system 2000

    YANG YuanXi


    The basic strategies In establishing the Chinese geodetic coordinate system 2000 have been summarized,including the definition of the coordinate system,the structure of the terrestrial reference frame,the functional and stochastic models involved in the realization of the reference frame as well as the Improvements of the adjustment procedures.First,the fundamental frame of the coordinate system is composed of the permanent GPS tracking network in China which is integrated into the international GPS service stations by combined adjustment,in order to guarantee the consistence between the international terrestrial reference system and the Chinese geodetic coordinate system.Second,the extended frame of the coordinate system is composed of the unified 2000' national GPS network which is Integrated by 6 nationwide GPS networks with more than 2500 stations under the controlling of the fundamental frame.Third,the densified frame is composed of national astronomical geodetic network with nearly 50 thousand stations which was updated by the combined adjustment with the 2000' national GPS network,thus the datum of the national astronomical geodetic network has been unified and the precision greatly improved.By the optimal data fusion method the influences of the datum errors,systematic errors and the outliers in the separated geodetic networks are weakened in the unified Chinese geodetic coordinate frame.The significance in application of the new geodetic coordinate system and the existing problems In the reference frame are described and analyzed.

  8. An Integrative Perspective on Interpersonal Coordination in Interactive Team Sports

    Silvan Steiner


    Full Text Available Interpersonal coordination is a key factor in team performance. In interactive team sports, the limited predictability of a constantly changing context makes coordination challenging. Approaches that highlight the support provided by environmental information and theories of shared mental models provide potential explanations of how interpersonal coordination can nonetheless be established. In this article, we first outline the main assumptions of these approaches and consider criticisms that have been raised with regard to each. The aim of this article is to define a theoretical perspective that integrates the coordination mechanisms of the two approaches. In doing so, we borrow from a theoretical outline of group action. According to this outline, group action based on a priori shared mental models is an example of how interpersonal coordination is established from the top down. Interpersonal coordination in reaction to the perception of affordances represents the bottom-up component of group action. Both components are inextricably involved in the coordination of interactive sports teams. We further elaborate on the theoretical outline to integrate a third, constructivist approach. Integrating this third approach helps to explain interpersonal coordination in game situations for which no shared mental models are established and game situations that remain ambiguous in terms of perceived affordances. The article describes how hierarchical, sequential, and complex dimensions of action organization are important aspects of this constructivist perspective and how mental models may be involved. A basketball example is used to illustrate how top-down, bottom-up and constructivist processes may be simultaneously involved in enabling interpersonal coordination. Finally, we present the implications for research and practice.

  9. Toward a theory of coordinating: Creating coordinating mechanisms in practice

    Jarzabkowski, P; Le, J. K.; Feldman, M. S.


    This paper uses a practice perspective to study coordinating as dynamic activities that are continuously created and modified in order to enact organizational relationships and activities. It is based on the case of Servico, an organization undergoing a major restructuring of its value chain in response to a change in government regulation. In our case, the actors iterate between the abstract concept of a coordinating mechanism referred to as end-to-end management and its performance in pract...

  10. Evaluating the Relational Coordination instrument

    Edwards, Kasper; Lundstrøm, Sanne Lykke


    and surgical performance. This has prompted the attention of both practitioners and politicians some of who perceive relational coordination as a means to attain better performance. The relational coordination instrument has been validated as a measure of teamwork from the following perspectives: internal...... consistency, interrater agreement and reliability, structural validity, content validity. However as relational coordination is being used as a diagnostics tool it is important to examine further if the instrument can measure changes. Indeed we need to know how precise and sensitive the instrument is when...

  11. The speciation of products from the reaction of {sup 51} Cr(VI) with mineral acids by high efficiency liquid chromatography; Especiacao dos produtos da reacao entre {sup 51} Cr(VI) e acidos minerais por cromatografia liquida de alta eficiencia

    Pezzin, Sergio H.; Collins, Carol H.; Collins, Kenneth E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica; Archundia, Cielita [Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico). Inst. de Ciencias Nucleares


    The speciation of the products from the reaction of {sup 51} Cr(VI) with concentrated acids (HClO{sub 4}, HCl e HF) was carried out by ion chromatography. The separation was made on a Partisil SCX (10 {mu}m) column, using HClO{sub 4} and Ca(ClO{sub 4}){sub 2} solutions as eluents. The eluates were measured by {gamma}-counting. The results for the reaction (1h) of carrier-free {sup 51} Cr(VI) with HCl show that 96.4% from the {sup 51} Cr is not retained on the column (anionic and/or neutral species). A similar result (92.7% not retained) is observed in a Cr(VI)-HF system. However, for the reaction with HClO{sub 4}, 82% of the {sup 51} Cr was observed as a +3 species and only 5.9% as anionic and/or neutral species. (author)

  12. Multi-Objective Coordinated Scheduling of Electric Vehicles and Renewable Generation Based on Improved Chemical Reaction Optimization Algorithm%基于改进化学反应优化算法的电动汽车与可再生能源多目标协同调度

    张智晟; 温令云; 李国; 张伟


    To mitigate the impact of fluctuation of renewable generation output on power grid and accelerate the population of electric vehicles (EV), taking the minimized output fluctuation of renewable generation and the maximized income of EV users as objective function and considering the constraints of the electricity quantity stored in the battery, the charging/discharging power and the charging/discharging times, a multi-objective coordinated scheduling model, in which the grid-connectible EV, wind power generation system and photovoltaic (PV) generation system are taken into account simultaneously, is established. A virtual ideal molecular based multi-objective improved chemical reaction optimization algorithm(CROA) is proposed, and the established model is solved by the proposed algorithm. In allusion to such defects of CROA as slow convergence and low accuracy, the update mode of particle swarm optimization algorithm is integrated with the improved CROA. Results of calculation example show that through reasonably arranging the charging/discharging of EV, the output fluctuation of renewable generation can be effectively suppressed and the income of EV users can be increased. Comparison results show that the virtual ideal molecular based improved multi-objective CROA possesses strong searching ability.%为减小可再生能源出力波动对电网的影响以及加快电动汽车的普及速率,以最小化可再生能源的出力波动和最大化电动汽车用户收益为目标函数,计及电池储存电量约束、充放电功率约束和充放电次数约束等条件,建立了同时计及可入网电动汽车、风力发电和光伏发电系统的多目标协同调度模型。提出了基于虚拟理想分子的多目标改进化学反应优化算法(chemical reaction optimization algorithm , CROA),并用该算法对模型进行了求解,针对化学反应算法收敛速度慢、精度低的缺陷,在算法中融入了粒子群优化算法的更

  13. Some properties of emission coordinates

    Pozo, J M


    4 emitters broadcasting an increasing electromagnetic signal generate a system of relativistic coordinates for the space-time, called emission coordinates. Their physical realization requires an apparatus similar to the one of the Global Navigation Satellite Systems (GNSS). Several relativistic corrections are utilized for the current precisions, but the GNSS are conceived as classical (Newtonian) systems, which has deep implications in the way of operating them. The study of emission coordinates is an essential step in order to develop a fully relativistic theory of positioning systems. This talk presents some properties of emission coordinates. In particular, we characterize how any observer sees a configuration of satellites giving a degenerated system and show that the trajectories of the satellites select a unique privileged observer at each point and, for any observer, a set of 3 orthogonal spatial axes.

  14. Coordination Games on Dynamical Networks

    Enea Pestelacci


    Full Text Available We propose a model in which agents of a population interacting according to a network of contacts play games of coordination with each other and can also dynamically break and redirect links to neighbors if they are unsatisfied. As a result, there is co-evolution of strategies in the population and of the graph that represents the network of contacts. We apply the model to the class of pure and general coordination games. For pure coordination games, the networks co-evolve towards the polarization of different strategies. In the case of general coordination games our results show that the possibility of refusing neighbors and choosing different partners increases the success rate of the Pareto-dominant equilibrium.

  15. Fedosov supermanifolds: II. Normal coordinates

    Geyer, B; Geyer, Bodo; Lavrov, Peter


    The study of recently introduced Fedosov supermanifolds is continued. Using normal coordinates, properties of even and odd symplectic supermanifolds endowed with a symmetric connection respecting given sympletic structure are studied.

  16. Surface normals and barycentric coordinates

    Mullineux Glen


    Full Text Available The normal to a triangular parametric surface is investigated where the parameters used are barycentric coordinates. Formulae for the normal are obtained for non-rational and rational surfaces.

  17. Ellipsoidal analysis of coordination polyhedra

    Cumby, James; Attfield, J. Paul


    The idea of the coordination polyhedron is essential to understanding chemical structure. Simple polyhedra in crystalline compounds are often deformed due to structural complexity or electronic instabilities so distortion analysis methods are useful. Here we demonstrate that analysis of the minimum bounding ellipsoid of a coordination polyhedron provides a general method for studying distortion, yielding parameters that are sensitive to various orders in metal oxide examples. Ellipsoidal analysis leads to discovery of a general switching of polyhedral distortions at symmetry-disallowed transitions in perovskites that may evidence underlying coordination bistability, and reveals a weak off-centre `d5 effect' for Fe3+ ions that could be exploited in multiferroics. Separating electronic distortions from intrinsic deformations within the low temperature superstructure of magnetite provides new insights into the charge and trimeron orders. Ellipsoidal analysis can be useful for exploring local structure in many materials such as coordination complexes and frameworks, organometallics and organic molecules.

  18. Capture reactions

    Endt, P.M.


    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation proces

  19. Allergic Reactions

    ... round, they may be caused by exposure to indoor allergens such as dust mites, indoor molds or pets. Urticaria, or hives, is characterized ... home. Video: What is an allergic reaction? » Utility navigation Donate Annual meeting Browse your conditions Check pollen ...

  20. Kaluza's theory in generalized coordinates

    García-Perciante, A L; García-Colin, L S; Garcia-Perciante, Ana Laura; Sandoval-Villalbazo, Alfredo


    Maxwell's equations can be obtained in generalized coordinates by considering the electromagnetic field as an external agent. The work here presented shows how to obtain the electrodynamics for a charged particle in generalized coordinates eliminating the concept of external force. Based on Kaluza's formalism, the one here presented extends the 5x5 metric into a 6x6 space-time giving enough room to include magnetic monopoles in a very natural way.

  1. Coordination theory and collaboration technology

    Olson, Gary M; Smith, John B


    The National Science Foundation funded the first Coordination Theory and Collaboration Technology initiative to look at systems that support collaborations in business and elsewhere. This book explores the global revolution in human interconnectedness. It will discuss the various collaborative workgroups and their use in technology. The initiative focuses on processes of coordination and cooperation among autonomous units in human systems, in computer and communication systems, and in hybrid organizations of both systems. This initiative is motivated by three scientific issues which have been

  2. CPN Models in General Coordinates

    Barnes, K J


    An analysis of CPN models is given in terms of general coordinates or arbitrary interpolating fields.Only closed expressions made from simple functions are involved.Special attention is given to CP2 and CP4. In the first of these the retrieval of stereographic coordinates reveals the hermitian form of the metric. A similar analysis for the latter case allows comparison with the Fubini-Study metric.

  3. Inflation, Growth and Policy Coordination

    Renato E. Reside Jr.; Parantap Basu


    The effect of monetary policy on output growth and inflation is examined in a monetary endogenous growth model with an explicit banking sector that intermediates capital. Monetary policy is coordinated with fiscal policy in the sense that all the seigniorage revenue gleaned through the inflation tax is spent to make efficient provision of public services. With the reserve requirement and money growth as instruments, policy coordination implies that one instrument may be solved endogenously wh...

  4. Managing interteam coordination within and between organizations

    de Vries, Thomas Arend


    To accomplish complex tasks and effectively respond to environmental contingencies, teams must coordinate task-related issues with other teams (i.e., interteam coordination). Regrettably, interteam coordination is often complicated by misunderstandings that can arise from differences in teams’

  5. Conforming to coordinate: children use majority information for peer coordination.

    Grueneisen, Sebastian; Wyman, Emily; Tomasello, Michael


    Humans are constantly required to coordinate their behaviour with others. As this often relies on everyone's convergence on the same strategy (e.g., driving on the left side of the road), a common solution is to conform to majority behaviour. In this study, we presented 5-year-old children with a coordination problem: To retrieve some rewards, they had to choose the same of four options as a peer partner--in reality a stooge--whose decision they were unable to see. Before making a choice, they watched a video showing how other children from their partner's peer group had behaved; a majority chose the same option and a minority chose a different one. In a control condition, children watched the same video but could then retrieve the reward irrespective of their partner's choice (i.e., no coordination was necessary). Children followed the majority more often when coordination was required. Moreover, conformers mostly justified their choices by referring to the majority from the video demonstration. This study is the first to show that young children are able to strategically coordinate decisions with peers by conforming to the majority.

  6. Metallogels from Coordination Complexes, Organometallic, and Coordination Polymers.

    Dastidar, Parthasarathi; Ganguly, Sumi; Sarkar, Koushik


    A supramolecular gel results from the immobilization of solvent molecules on a 3D network of gelator molecules stabilized by various supramolecular interactions that include hydrogen bonding, π-π stacking, van der Waals interactions, and halogen bonding. In a metallogel, a metal is a part of the gel network as a coordinated metal ion (in a discrete coordination complex), as a cross-linking metal node with a multitopic ligand (in coordination polymer), and as metal nanoparticles adhered to the gel network. Although the field is relatively new, research into metallogels has experienced a considerable upsurge owing to its fundamental importance in supramolecular chemistry and various potential applications. This focus review aims to provide an insight into the development of designing metallogelators. Because of the limited scope, discussions are confined to examples pertaining to metallogelators derived from discrete coordination complexes, organometallic gelators, and coordination polymers. This review is expected to enlighten readers on the current development of designing metallogelators of the abovementioned class of molecules. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Cyclometalation reactions five-membered ring products as universal reagents

    Omae, Iwao


    Offering unrivalled breadth of coverage on the topic, this review of cyclometalation reactions and organometallic intramolecular-coordination five-membered ring products includes discussion of vital commercial aspects such as synthetic applications.

  8. Back Reaction of Cosmological Perturbations

    Brandenberger, R H


    The presence of cosmological perturbations affects the background metric and matter configuration in which the perturbations propagate. This effect, studied a long time ago for gravitational waves, also is operational for scalar gravitational fluctuations, inhomogeneities which are believed to be more important in inflationary cosmology. The back-reaction of fluctuations can be described by an effective energy-momentum tensor. The issue of coordinate invariance makes the analysis more complicated for scalar fluctuations than for gravitational waves. We show that the back-reaction of fluctuations can be described in a diffeomorphism-invariant way. In an inflationary cosmology, the back-reaction is dominated by infrared modes. We show that these modes give a contribution to the effective energy-momentum tensor of the form of a negative cosmological constant whose absolute value grows in time. We speculate that this may lead to a self-regulating dynamical relaxation mechanism for the cosmological constant. This ...

  9. Werner coordination chemistry and neurodegeneration.

    Telpoukhovskaia, Maria A; Orvig, Chris


    Neurodegenerative diseases are capturing the world's attention as being the next set of diseases we must tackle collectively. Not only are the patients experiencing gradual cognitive and physical decline in most cases, but these diseases are fatal with no prevention currently available. As these diseases are progressive, providing care and symptom treatment for the ageing population is becoming both a medical and a financial challenge. This review discusses how Werner coordination chemistry plays a role in three diseases - those of Alzheimer's, Parkinson's, and prions. Metal ions are considered to be involved in these diseases in part via their propensity to cause toxic aggregation of proteins. First, the coordination of metal ions, with emphasis on copper(II), to metalloproteins that are hallmarks of these diseases - amyloid β, α-synuclein, and prion, respectively - will be discussed. We will present the current understanding of the metal coordination environments created by the amino acids of these proteins, as well as metal binding affinity. Second, a diverse set of examples of rationally designed metal chelators to outcompete this deleterious binding will be examined based on coordination mode and affinity toward bio-relevant metal ions. Overall, this review will give a general overview of protein and metal chelator coordination environments in neurodegenerative diseases.

  10. Efeito do íon comum na reação de hidratação do MgO Common-ion effect on the MgO hydration reaction

    L. F. Amaral


    Full Text Available Concretos refratários contendo óxido de magnésio (MgO apresentam grande interesse tecnológico por unir a versatilidade e a liberdade de design dos refratários monolíticos aos benefícios conferidos pelo MgO, tais como, elevada refratariedade e resistência a escórias básicas. Entretanto, o MgO é facilmente hidratado formando Mg(OH2 e essa reação leva a uma grande expansão volumétrica do material, o que limita sua aplicação em concretos refratários. Para encontrar soluções que minimizem esse efeito, torna-se necessário uma melhor compreensão a respeito dos fatores que afetam essa reação, como a temperatura. Neste trabalho, o impacto do deslocamento de equilíbrio químico conhecido como efeito do íon comum na hidratação do MgO foi avaliado na presença de diversos aditivos (MgCl2, MgSO4, CaCl2 e KOH. Entre os aditivos, o CaCl2 comportou-se como um retardador da reação, enquanto um comportamento oposto foi obtido para o KOH. O MgCl2 e o MgSO4 apresentaram ambos os efeitos dependendo de suas concentrações na suspensão. As possíveis causas para esses comportamentos são discutidas no artigo. Os resultados foram abordados considerando-se a termodinâmica e a cinética da reação, bem como os conseqüentes danos mecânicos causados ao material.MgO based refratory castables present a wide technological interest because they add together the versatility and the installation efficiency of the monolithic refractories to the intrinsic MgO properties, such as high refractoriness and resistance to basic slag corrosion. Nevertheless, MgO is easily hydrated by water generating Mg(OH2 and this reaction causes a volumetric expansion that could lead to material’s breakdown and inhibit its application in refractory castables. In order to develop solutions to minimize this effect, it is necessary a better understanding of the main variables involved in this reaction, such as temperature. In this work, the impact of the chemical

  11. Coordination chemistry in the design of heterogeneous photocatalysts.

    Gao, Chao; Wang, Jin; Xu, Hangxun; Xiong, Yujie


    Heterogeneous catalysts have been widely used for photocatalysis, which is a highly important process for energy conversion, owing to their merits such as easy separation of catalysts from the reaction products and applicability to continuous chemical industry and recyclability. Yet, homogenous photocatalysis receives tremendous attention as it can offer a higher activity and selectivity with atomically dispersed catalytic sites and tunable light absorption. For this reason, there is a major trend to combine the advantages of both homogeneous and heterogeneous photocatalysts, in which coordination chemistry plays a role as the bridge. In this article, we aim to provide the first systematic review to give a clear picture of the recent progress from taking advantage of coordination chemistry. We specifically summarize the role of coordination chemistry as a versatile tool to engineer catalytically active sites, tune light harvesting and maneuver charge kinetics in heterogeneous photocatalysis. We then elaborate on the common fundamentals behind various materials systems, together with key spectroscopic characterization techniques and remaining challenges in this field. The typical applications of coordination chemistry in heterogeneous photocatalysis, including proton reduction, water oxidation, carbon dioxide reduction and organic reactions, are highlighted.

  12. COCO: Conversion of Celestial Coordinates

    Wallace, Patrick


    The COCO program converts star coordinates from one system to another. Both the improved IAU system, post-1976, and the old pre-1976 system are supported. COCO can perform accurate transformations between multiple coordinate systems. COCO's user-interface is spartan but efficient and the program offers control over report resolution. All input is free-format, and defaults are provided where this is meaningful. COCO uses SLALIB (ascl:1403.025) and is distributed as part of the Starlink software collection (ascl:1110.012).

  13. A coordination language for databases

    Li, Ximeng; Wu, Xi; Lluch Lafuente, Alberto


    We present a coordination language for the modeling of distributed database applications. The language, baptized Klaim-DB, borrows the concepts of localities and nets of the coordination language Klaim but re-incarnates the tuple spaces of Klaim as databases. It provides high-level abstractions...... in the semantics. The use of the language is illustrated in a scenario where the sales from different branches of a chain of department stores are aggregated from their local databases. Raising the abstraction level and encapsulating integrity checks in the language primitives have benefited the modeling task...

  14. Supramolecular Organization of Porphyrin and Phthalocyanine by Complementary Coordination

    Yoshiaki; Kobuke; Masakuni; Fujita; Toshimasa; Sugimura; Akiharu; Satake


    1 Results We have already established a methodology of supramolecular organization of porphyrin and phthalocyanine by complementary coordination of the imidazolyl substituent to their metal centers.Since the stability constants reached a range of 1011 to 1012 M-1 in nonpolar solvents,it allowed construction of stable structures such as special pair of photosynthetic reaction center and light-harvesting antenna complex of photosynthetic bacteria.Here,we report one-dimensional array of porphyrin for the d...

  15. 7 CFR 22.201 - Coordination.


    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Coordination. 22.201 Section 22.201 Agriculture Office of the Secretary of Agriculture RURAL DEVELOPMENT COORDINATION Roles and Responsibilities of Federal Government § 22.201 Coordination. The following identifies types and levels of coordination: (a) Washington...

  16. 15 CFR 923.56 - Plan coordination.


    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Plan coordination. 923.56 Section 923... COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Coordination, Public Involvement and National Interest § 923.56 Plan coordination. (a) The management program must be coordinated with local, areawide,...

  17. 40 CFR 109.6 - Coordination.


    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Coordination. 109.6 Section 109.6..., LOCAL AND REGIONAL OIL REMOVAL CONTINGENCY PLANS § 109.6 Coordination. For the purposes of coordination... coordination of these contingency plans with the National Oil and Hazardous Materials Pollution...

  18. 29 CFR 42.8 - Coordination plan.


    ... 29 Labor 1 2010-07-01 2010-07-01 true Coordination plan. 42.8 Section 42.8 Labor Office of the Secretary of Labor COORDINATED ENFORCEMENT § 42.8 Coordination plan. (a) Based upon, among other things, the... coordination plan concerning farm labor-related responsibilities of the Department, including migrant housing...

  19. 33 CFR 165.8 - Geographic coordinates.


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 165.8... Geographic coordinates. Geographic coordinates expressed in terms of latitude or longitude, or both, are not... 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic...

  20. The Convex Coordinates of the Symmedian Point

    Boyd, J. N.; Raychowdhury, P. N.


    In this note, we recall the convex (or barycentric) coordinates of the points of a closed triangular region. We relate the convex and trilinear coordinates of the interior points of the triangular region. We use the relationship between convex and trilinear coordinates to calculate the convex coordinates of the symmedian point of the triangular…

  1. 78 FR 73819 - Forest Resource Coordinating Committee


    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of...-18, 2013 meeting of the Forest Resource Coordinating Committee due to the Government partial shutdown... INFORMATION CONTACT: Maya Solomon, Forest Resource Coordinating Committee Program Coordinator; by phone at...

  2. The emergent coordination of cognitive function.

    Kello, Christopher T; Beltz, Brandon C; Holden, John G; Van Orden, Guy C


    1/f scaling has been observed throughout human physiology and behavior, but its origins and meaning remain a matter of debate. Some argue that it is a byproduct of ongoing processes in the brain or body and therefore of limited relevance to psychological theory. Others argue that 1/f scaling reflects a fundamental aspect of all physiological and cognitive functions, namely, that they emerge in the balance of independent versus interdependent component activities. In 4 experiments, series of key-press responses were used to test between these 2 alternative explanations. The critical design feature was to take 2 measures of each key-press response: reaction time and key-contact duration. These measures resulted in 2 parallel series of intrinsic fluctuations for each series of key-press responses. Intrinsic fluctuations exhibited 1/f scaling in both reaction times and key-contact durations, yet the 2 measures were uncorrelated with each other and separately perturbable. These and other findings indicate that 1/f scaling is too pervasive to be idiosyncratic and of limited relevance. It is instead argued that 1/f scaling reflects the coordinative, metastable basis of cognitive function. 2007 APA

  3. Coordination Frictions and Job Heterogeneity

    Kennes, John; le Maire, Christian Daniel

    This paper develops and extends a dynamic, discrete time, job to worker matching model in which jobs are heterogeneous in equilibrium. The key assumptions of this economic environment are (i) matching is directed and (ii) coordination frictions lead to heterogeneous local labor markets. We de- rive...

  4. Terrestrial Coordinate Systems and Frames

    Boucher, C.; Murdin, P.


    A terrestrial reference system (TRS) is a spatial reference system corotating with the Earth in its DIURNAL MOTION in space. In such a system, the positions of points anchored on the Earth's solid surface have coordinates which have only small variations with time, as a result of geophysical effects (tectonic or tidal deformations; see TECTONICS, EARTH'S INTERIOR, TIDES). A terrestrial reference ...

  5. Archimedes' Principle in General Coordinates

    Ridgely, Charles T.


    Archimedes' principle is well known to state that a body submerged in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the body. Herein, Archimedes' principle is derived from first principles by using conservation of the stress-energy-momentum tensor in general coordinates. The resulting expression for the force is…

  6. Coordinated Exploration for Grand Challenges

    Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph


    on the acceptance and support of important stakeholders. In this study, we suggest that search consortia are more likely to receive funding when they include representatives of stakeholder concerns, so-called advocacy groups. We extend theory on coordinated exploration in joint search by integrating mechanisms from...

  7. Coordinating talk and practical action

    Oshima, Sae; Streeck, Jürgen


    This paper investigates how talk and practical action are coordinated during one type of activity involving professional communication: the service-assessment sequence in hair salons. During this activity, a practical inspection of the haircut must be coupled with sequentially produced verbal act...

  8. Archimedes' Principle in General Coordinates

    Ridgely, Charles T.


    Archimedes' principle is well known to state that a body submerged in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the body. Herein, Archimedes' principle is derived from first principles by using conservation of the stress-energy-momentum tensor in general coordinates. The resulting expression for the force is…

  9. Coordinating talk and practical action

    Oshima, Sae; Streeck, Jürgen


    . Our analysis of four examples reveals that there is no fixed relationship between the organization of talk and practical action. Instead, people manipulate this relationship on a moment-by-moment basis, often coordinating the two into a single, integral package, or relying on one stream of action...

  10. Early insulin therapy Coordination Council

    Marina Vladimirovna Shestakova


    Full Text Available Coordination Council has denoted the importance of adherence to Russian and international guidelines and prominent role of insulin therapy in management of type 2 diabetes mellitus (T2DM. Insulin therapy in T2DM preserves endogenous insulin secretion, prevents or decelerates development of microvascular complications and is known to be the most effective glucose-lowering treatment.

  11. Spallation reactions; Reactions de spallation

    Cugon, J.


    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from {approx} 0.1 to {approx} 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author). 84 refs.

  12. Thermophysical characterization and thermal cycling stability of two TCM: CaCl2 and zeolite

    Barreneche, C.; Fernández, A.I.; Cabeza, L.F.; Cuypers, R.


    At this moment, the global energy consumption in buildings is around 40% of the total energy consumption in developed countries. Thermal energy storage (TES) is presented as one way to address this energy-related problem proposing an alternative to reduce the gap between energy supply and energy

  13. Thermophysical characterization and thermal cycling stability of two TCM: CaCl2 and zeolite

    Barreneche, C.; Fernández, A.I.; Cabeza, L.F.; Cuypers, R.


    At this moment, the global energy consumption in buildings is around 40% of the total energy consumption in developed countries. Thermal energy storage (TES) is presented as one way to address this energy-related problem proposing an alternative to reduce the gap between energy supply and energy dem




    Full Text Available Calcium chloride is an inorganic salt used in its solid state or as aqueous solutions in a multitude of research and industrial areas going from chemical industry to food, cosmetics or drugs production. This paper was directed to establish mathematical models relating its density and dynamic viscosity with factors such as temperature and concentration since it is known that these properties present a high influence on appropriate transport pipes dimensions and industrial equipment choosing and / or designing processes. The assessment and selection of the adequate models were realized by testing various software’s and equations. The obtained results revealed that calcium chloride aqueous solutions studied thermodynamic properties can accurately be expressed by quadratic (density and respectively by linear equations (dynamic viscosity or by more complex equations. Correlation coefficient, relative error and ANOVA values revealed no significant differences between experimental and calculated data.

  15. Solving Einstein's Equations With Dual Coordinate Frames

    Scheel, M A; Lindblom, L; Pfeiffer, H P; Rinne, O; Teukolsky, S A; Kidder, Lawrence E.; Lindblom, Lee; Pfeiffer, Harald P.; Rinne, Oliver; Scheel, Mark A.; Teukolsky, Saul A.


    A method is introduced for solving Einstein's equations using two distinct coordinate systems. The coordinate basis vectors associated with one system are used to project out components of the metric and other fields, in analogy with the way fields are projected onto an orthonormal tetrad basis. These field components are then determined as functions of a second independent coordinate system. The transformation to the second coordinate system can be thought of as a mapping from the original ``inertial'' coordinate system to the computational domain. This dual-coordinate method is used to perform stable numerical evolutions of a black-hole spacetime using the generalized harmonic form of Einstein's equations in coordinates that rotate with respect to the inertial frame at infinity; such evolutions are found to be generically unstable using a single rotating coordinate frame. The dual-coordinate method is also used here to evolve binary black-hole spacetimes for several orbits. The great flexibility of this met...

  16. Growing string method with interpolation and optimization in internal coordinates: method and examples.

    Zimmerman, Paul M


    The growing string method (GSM) has proven especially useful for locating chemical reaction paths at low computational cost. While many string methods use Cartesian coordinates, these methods can be substantially improved by changes in the coordinate system used for interpolation and optimization steps. The quality of the interpolation scheme is especially important because it determines how close the initial path is to the optimized reaction path, and this strongly affects the rate of convergence. In this article, a detailed description of the generation of internal coordinates (ICs) suitable for use in GSM as reactive tangents and in string optimization is given. Convergence of reaction paths is smooth because the IC tangent and orthogonal directions are better representations of chemical bonding compared to Cartesian coordinates. This is not only important quantitatively for reducing computational cost but also allows reaction paths to be described with smoothly varying chemically relevant coordinates. Benchmark computations with challenging reactions are compared to previous versions of GSM and show significant speedups. Finally, a climbing image scheme is included to improve the quality of the transition state approximation, ensuring high reliability of the method.

  17. Managing Coordinator, Educational or Entrepreneurial Coordinator: Course Coordinator Profile Analysis at Private HEIS

    Mariana Augusta de Araújo Silva


    Full Text Available Higher Education dynamics is impacted by political, economic and financial interference. In parallel, the Ministry of Education and Culture (MEC is strict in its reviews to ensure Brazilian higher education is appreciated and promoted. The purpose of this study is to identify the profile of Course Coordinators and factors that might improve, at the surveyed HEIs, this professional´s relationship with students, teaching staff and Directors. Literature was searched and reviewed so as to collect subject matter pertaining issues. A quantitative research approach was employed and objectives were of exploratory descriptive nature since this technique ensures extended comprehension of the investigated phenomenon, whilst data was gathered via personal interviews. The object of investigation comprised all Course Coordinators of the Estácio/Natal Group in Brazil´s four units. The survey´s tool comprises: 13 closed questions to identify the Coordinator´s profile; 17 questions with a 5 point Likert score scale to identify the entrepreneurial profile; 42 also resorting to a 5 point Likert score scale to measure the dimensions of the Coordinator´s activities and 4 open, optional questions to measure difficulties and possibilities that impact the development of an entrepreneurial course management approach. The study employed both a statistical method (data analysis and descriptive statistics. Findings lead to the conclusion that information and knowledge gathered support researched HEIs in their overcoming of challenges, amongst which encouraging strategic course management and innovation, focused on implementing a new vision of the Course Coordinator, as professionals that master how to balance management and pedagogical skills, whilst innovating by resorting to entrepreneurial competencies.

  18. Coordination and metalation bifunctionality of Cu with 5,10,15,20-tetra(4-pyridyl)porphyrin: toward a mixed-valence two-dimensional coordination network.

    Li, Yang; Xiao, Jie; Shubina, Tatyana E; Chen, Min; Shi, Ziliang; Schmid, Martin; Steinrück, Hans-Peter; Gottfried, J Michael; Lin, Nian


    We investigated the coordination self-assembly and metalation reaction of Cu with 5,10,15,20-tetra(4-pyridyl)porphyrin (2HTPyP) on a Au(111) surface by means of scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. 2HTPyP was found to interact with Cu through both the peripheral pyridyl groups and the porphyrin core. Pairs of pyridyl groups from neighboring molecules coordinate Cu(0) atoms, which leads to the formation of a supramolecular metal-organic coordination network. The network formation occurs at room temperature; annealing at 450 K enhances the process. The interaction of Cu with the porphyrin core is more complex. At room temperature, formation of an initial complex Cu(0)-2HTPyP is observed. Annealing at 450 K activates an intramolecular redox reaction, by which the coordinated Cu(0) is oxidized to Cu(II) and the complex Cu(II)TPyP is formed. The coordination network consists then of Cu(II) complexes linked by Cu(0) atoms; that is, it represents a mixed-valence two-dimensional coordination network consisting of an ordered array of Cu(II) and Cu(0) centers. Above 520 K, the network degrades and the Cu atoms in the linking positions diffuse into the substrate, while the Cu(II)TPyP complexes form a close-packed structure that is stabilized by weak intermolecular interactions. Density functional theory investigations show that the reaction with Cu(0) proceeds via formation of an initial complex between metal atom and porphyrin followed by formation of Cu(II) porphyrin within the course of the reaction. The activation barrier of the rate limiting step was found to be 24-37 kcal mol(-1) depending on the method used. In addition, linear coordination of a Cu atom by two CuTPyP molecules is favorable according to gas-phase calculations. © 2012 American Chemical Society

  19. Supply Chain Reorganization and Coordination

    WANG Feng-bin


    Three generic forms of governance--hierarchy, hybrid and market are proposed in the newinstitutional economics, giving an abstract description of alternative coordination and control mechanisms forgeneral use. While this theory is known as far away from being operational and specified, a few researchersin the management and organization area are trying to extend Galbraith and/or Mintzberg's organizationaldesign theories into the application of logistical coordination for obtaining a smooth flow of products along thesupply chain within and without the focal organization. In this paper, we present an explorative case study onthe design of various organizational architectures of logistics activities and their relevant coordinationmechanisms, especially internal and external contracts as one new kind of hybrid mechanisms forcoordinating effective supply chains.

  20. [Transplant coordinator: organ donation process].

    Gironés-Guillem, Purificación; Camaño-Puig, Ramón; Lillo-Crespo, Manuel


    Spain is a leader in organ donations although it seems that this number does not increase in the same proportion that the waiting list and it is necessary to decrease the refusal situations, which are ~16%. Analytic study. We review the reports prepared by the coordinators of transplants archived at the hospital La Fe during the period between May 1, 2004 and December 31, 2007, resulting in conceptualization and categorization. Sixty-nine topics were obtained from the point of view of the family and 11 from the point of view of the interviewer. After its conceptualization, codification and classification, we proceeded to create an appropriate text. Certain guidelines may be offered that allow us to standardize the action of transplant coordinators during the interview and to be more effective.


    Martin HROMÁDKA


    Full Text Available Both low cost carriers ‘fresh wind’ and liberalisation of ground handling market makes airlines to be cost-wise in every single field. Thus, ground handling contract are cutting down in terms of their costs. Handling companies struggle with pressure being put from the market environment, they rush 25 minutes turnaround with couple of people. This can be potentially dangerous from the safety point of view. One of possible solutions seems to be introducing turnaround coordinator, person who would supervise the ramp handling procedures. This paper discusses the role of turnaround coordinator within the aircraft turnaround process. Duties and responsibilities of this person are described. However, not every airport is staffing this position. The survey shows that smaller airports pay much more attention to this issue than the big ones.

  2. Porphyrin coordination polymer nanospheres and nanorods

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.


    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  3. Porphyrin coordination polymer nanospheres and nanorods

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.


    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  4. Resolution enhancement in tilted coordinates

    Hariri Naghadeh, Diako; Keith Morley, Christopher


    Deconvolution is applied to remove source wavelet effects from seismograms. The results are resolution enhancement that enables detection of thin layers. Following enhancement of resolution, low frequency and high angle reflectors, particularly at great depth, appear as low amplitude and semi-invisible reflectors that are difficult to track and pick. A new approach to enhance resolution is introduced that estimates a derivative using continuous wavelet transform in tilted coordinates. The results are compared with sparse spike deconvolution, curvelet deconvolution and inverse quality filtering in wavelet domain. The positive consequence of the new method is to increase sampling of high dip features by changing the coordinate system from Cartesian to tilted. To compare those methods a complex data set was chosen that includes high angle faults and chaotic mass transport complex. Image enhancement using curvelet deconvolution shows a chaotic system as a non-chaotic one. The results show that sparse spike deconvolution and inverse quality filtering in wavelet domain are able to enhance resolution more than curvelet deconvolution especially at great depth but it is impossible to follow steep dip reflectors after resolution enhancement using these methods, especially when their apparent dips are more than 45°. By estimating derivatives in a continuous wavelet transform from tilted data sets similar resolution enhancement as the other deconvolution methods is achieved but additionally steep dipping reflectors are imaged much better than others. Subtracted results of the enhanced resolution data set using new method and the other introduced methods show that steeply dipping reflectors are highlighted as a particular ability of the new method. The results show that high frequency recovery in Cartesian co-ordinate is accompanied by inability to image steeply dipping reflectors especially at great depths. Conversely recovery of high frequency data and imaging of the data


    Saeideh MIRAFKHAMI


    Full Text Available ObjectiveIn this article, a motor skill disorder called developmental coordination disorder (DCD, that is usually first diagnosed during childhood, is explained and discussed. In the year 1987, DCD was formally recognized as a distinct disorder in children by the American Psychiatric Association  (APA. DCD is a generalized term for the children who have some degrees of impairment in the development of motor coordination and therefore have difficulties with physical skills which significantly interfere with their academic achievements and /or performing everyday activities. As they develop, other age-related tasks are also below average. Because these impairment & conditions are often associated with emotional distress, they can seriously interfere with the person's everyday life and social relationships. Reviews indicate that most of the training rocedures have only a limited effect on the development of general coordination, and that they have no effect at all on academic progress.This includes approaches based on assumed underlying deficiencies such as sensory integration deficits and kinesthetic functioning deficits, as well as the more traditional perceptual - motor training. One new approach is Cognitive Orientation to daily Occupational Performance (CO-OP, based on problem - solving strategies and guided discovery of the child and task specific strategies. The aim of this article was to inform, promote and disseminate more information about some difficulties in applying the diagnostic criteria for DCD. Also, a brief review of the researches on the intervention methods is presented.Keywords: Developmental coordination disorder, Motor skills disorder, Childhood disorder, Intervention methods

  6. Coordination strategies of crew management

    Conley, Sharon; Cano, Yvonne; Bryant, Don


    An exploratory study that describes and contrasts two three-person flight crews performing in a B-727 simulator is presented. This study specifically attempts to delineate crew communication patterns accounting for measured differences in performance across routine and nonroutine flight patterns. The communication patterns in the two crews evaluated indicated different modes of coordination, i.e., standardization in the less effective crew and planning/mutual adjustment in the more effective crew.

  7. Coordination strategies of crew management

    Conley, Sharon; Cano, Yvonne; Bryant, Don


    An exploratory study that describes and contrasts two three-person flight crews performing in a B-727 simulator is presented. This study specifically attempts to delineate crew communication patterns accounting for measured differences in performance across routine and nonroutine flight patterns. The communication patterns in the two crews evaluated indicated different modes of coordination, i.e., standardization in the less effective crew and planning/mutual adjustment in the more effective crew.

  8. Understanding chemical binding using the Berlin function and the reaction force

    Chakraborty, Debajit; Cárdenas, Carlos; Echegaray, Eleonora; Toro-Labbe, Alejandro; Ayers, Paul W.


    We use the derivative of the electron density with respect to the reaction coordinate, interpreted through the Berlin binding function, to identify portions of the reaction path where chemical bonds are breaking and forming. The results agree with the conventional description for SN2 reactions, but they are much more general and can be used to elucidate other types of reactions also. Our analysis offers support for, and detailed information about, the use of the reaction force profile to separate the reaction coordinates into intervals, each with characteristic extents of geometry change and electronic rearrangement.

  9. Coordinate unsaturation with fluorinated ligands

    Rack, J.L.; Hurlburt, P.K.; Anderson, O.P.; Strauss, S.H. [Colorado State Univ., Ft. Collins, CO (United States)


    The preparation and characterization of Zn(OTeF{sub 5}){sub 2} has resulted in a model compound with which to explore the concept of coordinative unsaturation. The coordination of solvents of varying donicity and dielectric constant to the Zn(II) ions in Zn(OTeF{sub 5}){sub 2} was studied by vapor phase monometry, NMR and IR spectroscopy, conductimetry, and X-Ray crystallography. The structures of [Zn(C{sub 6}H{sub 5}NO{sub 2}){sub 2}(OTeF{sub 5})2]2 and Zn(C{sub 6}H{sub 5}NO{sub 2}){sub 3}(OTEF{sub 5}){sub 2} demonstrate the electronic flexibility of some weakly coordinating solvents in that nitrobenzene can function as either an {eta}{sup 1}O or {eta}{sup 2}O,O`-ligand. The dependence of the number of bound solvent molecules and the degree of OTeF{sub 5}{minus} dissociation on solvent donor number and dielectric constant will be presented.


    Saeideh MIRAFKHAMI


    Full Text Available ObjectiveIn this article, a motor skill disorder called developmental coordination disorder (DCD, that is usually first diagnosed during childhood, is explained and discussed. In the year 1987, DCD was formally recognized as a distinct disorder in children by the American Psychiatric Association (APA. DCD is a generalized term for the children who have some degrees of impairment in the development of motor coordination and therefore have difficulties with physical skills which significantly interfere with their academic achievements and /or performing everyday activities. As they develop, other age-related tasks are also below average. Because these impairment & conditions are often associated with emotional distress, they can seriously interfere with the person's everyday life and social relationships. Reviews indicate that most of the training rocedures have only a limited effect on the development of general coordination, and that they have no effect at all on academic progress.This includes approaches based on assumed underlying deficiencies such as sensory integration deficits and kinesthetic functioning deficits, as well as the more traditional perceptual - motor training. One new approach is Cognitive Orientation to daily Occupational Performance (CO-OP, based on problem - solving strategies and guided discovery of the child and task specific strategies. The aim of this article was to inform, promote and disseminate more information about some difficulties in applying the diagnostic criteria for DCD. Also, a brief review of the researches on the intervention methods is presented.

  11. Reaction mechanism of -acylhydroxamate with cysteine proteases

    R Shankar; P Kolandaivel


    The gas-phase reaction mechanism of -acylhydroxamate with cysteine proteases has been investigated using ab initio and density functional theory. On the irreversible process, after breakdown of tetrahedral intermediate (INT1), small 1-2 anionotropic has been formed and rearranged to give stable by-products sulfenamide (P1) and thiocarbamate (P2) with considerable energy loss. While, on the reversible part of this reaction mechanism, intermediate (INT2) breaks down on oxidation, to form a stable product (P3). Topological and AIM analyses have been performed for hydrogen bonded complex in this reaction profile. Intrinsic reaction coordinates [IRC, minimum-energy path (MEP)] calculation connects the transition state between R-INT1, INT1-P1 and INT1-P2. The products P1, P2 and P3 are energetically more stable than the reactant and hence the reaction enthalpy is found to be exothermic.

  12. A novel 2D (3,5)-connected coordination framework with Zn 2(COO) 3 SBU

    Han, Lei; Xu, Lan-Ping; Zhao, Wen-Na


    A novel 2D Zn(II)-organic coordination framework, [Zn 2(hfipbb) 2] n ( 1) (hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoate)), has been synthesized under hydrothermal reaction. Single-crystal X-ray diffraction revealed that 1 is a (3,5)-connected coordination network based on Zn 2(COO) 3 secondary building unit and flexible V-shaped organic linkers. The luminescent property and thermal stability of 1 have also been investigated.

  13. Coordination of Passive Systems under Quantized Measurements

    De Persis, Claudio; Jayawardhana, Bayu


    In this paper we investigate a passivity approach to collective coordination and synchronization problems in the presence of quantized measurements and show that coordination tasks can be achieved in a practical sense for a large class of passive systems.

  14. Energy shaping for coordinating internally actuated vehicles


    This paper considers the stable coordination problem of two vehicles equipping with internal moving mass actuators.The coordinating and stabilizing control are derived by energy shaping. The proposed method is physically motivated and avoids cancelation or domination of nonlinearities.

  15. Dressed coordinates: The path-integral approach

    Casana, R.; Flores-Hidalgo, G.; Pimentel, B. M.


    The recently introduced dressed coordinates are studied in the path-integral approach. These coordinates are defined in the context of a harmonic oscillator linearly coupled to massless scalar field and it is shown that in this model the dressed coordinates appear as a coordinate transformation preserving the path-integral functional measure. The analysis also generalizes the sum rules established in a previous work.

  16. Noncommuting Coordinates in the Landau Problem

    Magro, Gabrielle


    Basic ideas about noncommuting coordinates are summarized, and then coordinate noncommutativity, as it arises in the Landau problem, is investigated. I review a quantum solution to the Landau problem, and evaluate the coordinate commutator in a truncated state space of Landau levels. Restriction to the lowest Landau level reproduces the well known commutator of planar coordinates. Inclusion of a finite number of Landau levels yields a matrix generalization.

  17. 7 CFR 23.3 - Coordination.


    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Coordination. 23.3 Section 23.3 Agriculture Office of the Secretary of Agriculture STATE AND REGIONAL ANNUAL PLANS OF WORK State Program § 23.3 Coordination... designate an official who will be responsible for the overall coordination of the authorized programs...

  18. 47 CFR 74.638 - Frequency coordination.


    ... frequency coordinated under this paragraph, the interference protection criteria in 47 CFR 101.105(a), (b), and (c) and the frequency usage coordination procedures in 47 CFR 101.103(d) will apply. (c) For each... 47 Telecommunication 4 2010-10-01 2010-10-01 false Frequency coordination. 74.638 Section...

  19. 47 CFR 87.305 - Frequency coordination.


    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency coordination. 87.305 Section 87.305... Flight Test Stations § 87.305 Frequency coordination. (a)(1) Each application for a new station license... prior coordinations and assignments on the proposed frequency(ies). The committee must also...

  20. 47 CFR 27.57 - International coordination.


    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false International coordination. 27.57 Section 27.57... COMMUNICATIONS SERVICES Technical Standards § 27.57 International coordination. (a) WCS operations in the border areas shall be subject to coordination with those countries and provide protection to non-U.S...

  1. 42 CFR 38.1 - Purpose; coordination.


    ... 42 Public Health 1 2010-10-01 2010-10-01 false Purpose; coordination. 38.1 Section 38.1 Public... DISASTER ASSISTANCE FOR CRISIS COUNSELING AND TRAINING § 38.1 Purpose; coordination. (a) Purpose. This part... providing those professional counseling services. (b) Coordination. The Secretary, acting through the...

  2. 45 CFR 98.82 - Coordination.


    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Coordination. 98.82 Section 98.82 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Indian Tribes § 98.82 Coordination. Tribal applicants shall coordinate as required by §§ 98.12 and 98.14 and: (a) To...

  3. Construction and minimality of coordinated linear systems

    Kempker, P.L.; Ran, A.C.M.; Schuppen, J.H. van


    Coordinated linear systems are a particular class of hierarchical systems with a top-to-bottom information structure, consisting of a coordinator system and two or more subsystems. This paper deals with the construction and minimality of coordinated linear systems. Construction procedures are given

  4. 45 CFR 1310.23 - Coordinated transportation.


    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Coordinated transportation. 1310.23 Section 1310... START PROGRAM HEAD START TRANSPORTATION Special Requirements § 1310.23 Coordinated transportation. (a) Each agency providing transportation services must make reasonable efforts to coordinate...

  5. 36 CFR 13.1104 - Coordinates.


    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Coordinates. 13.1104 Section 13.1104 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... Administrative Provisions § 13.1104 Coordinates. All coordinates referenced in this subpart use horizontal...

  6. 33 CFR 166.103 - Geographic coordinates.


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 166.103...) PORTS AND WATERWAYS SAFETY SHIPPING SAFETY FAIRWAYS General § 166.103 Geographic coordinates. Geographic coordinates expressed in terms of latitude or longitude, or both, are not intended for plotting on maps...

  7. 33 CFR 167.3 - Geographic coordinates.


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Geographic coordinates. 167.3...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.3 Geographic coordinates. Geographic coordinates are defined using North American 1927 Datum (NAD 27) unless indicated otherwise....

  8. Managing interteam coordination within and between organizations

    de Vries, Thomas Arend


    To accomplish complex tasks and effectively respond to environmental contingencies, teams must coordinate task-related issues with other teams (i.e., interteam coordination). Regrettably, interteam coordination is often complicated by misunderstandings that can arise from differences in teams’ langu

  9. 78 FR 34035 - Forest Resource Coordinating Committee


    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Forest Resource Coordinating Committee will meet via teleconference every month on... conference call will be posted to the Forest Resource Coordinating Committee Web site,

  10. 78 FR 57128 - Forest Resource Coordinating Committee


    ... Forest Service Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Forest Resource Coordinating Committee Meeting will meet in Rosslyn, Virginia. The... inspect comments received on the Forest Resource Coordinating Committee Web site at

  11. 78 FR 44519 - Forest Resource Coordinating Committee


    ... Office of the Secretary Forest Resource Coordinating Committee AGENCY: Forest Service, USDA. ACTION: Notice; Re-establishment of the Forest Resource Coordinating Committee and call for nominations. SUMMARY: The Department of Agriculture re-established the Forest Resource Coordinating Committee (Committee...

  12. Is fiscal policy coordination in EMU desirable?

    R.M.W.J. Beetsma; X. Debrun; F.J.G.M. Klaassen


    'It is widely argued that Europe's unified monetary policy calls for international coordination of fiscal policy. This paper surveys the issues involved with the coordination of fiscal policies as a demand management tool. We discuss ex-ante and ex-post coordination. The former operates through bind

  13. 49 CFR 214.325 - Train coordination.


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train coordination. 214.325 Section 214.325..., DEPARTMENT OF TRANSPORTATION RAILROAD WORKPLACE SAFETY Roadway Worker Protection § 214.325 Train coordination. Working limits established by a roadway worker through the use of train coordination shall comply with the...

  14. Coordination in serial-parallel image processing

    Wójcik, Waldemar; Dubovoi, Vladymyr M.; Duda, Marina E.; Romaniuk, Ryszard S.; Yesmakhanova, Laura; Kozbakova, Ainur


    Serial-parallel systems used to convert the image. The control of their work results with the need to solve coordination problem. The paper summarizes the model of coordination of resource allocation in relation to the task of synchronizing parallel processes; the genetic algorithm of coordination developed, its adequacy verified in relation to the process of parallel image processing.

  15. 77 FR 778 - Council Coordination Committee Meeting


    ... National Oceanic and Atmospheric Administration RIN 0648-XA918 Council Coordination Committee Meeting...), Commerce. ACTION: Notice of a public meeting. SUMMARY: NMFS will host a meeting of the Council Coordination... Reauthorization Act (MSRA) of 2006 established the Council Coordination Committee by amending Section 302 (16...

  16. Cationic zinc (II) dimers and one dimensional coordination polymer from ionic carboxylic acid

    Paladugu Suresh; Ganesan Prabusankar


    A rare example of chelating two tetra cationic paddle-wheel zinc dimers were synthesized from the reaction between flexible imidazolium carboxylate (LH2Br2) and corresponding zinc precursors. A zinc coordination polymer was synthesised by treating in situ generation of 2 in the presence of 4,4′-bipyridine. These new molecules, dimers and polymer, were characterized by FT-IR, NMR, UV-vis, fluorescent and single crystal X-ray diffraction techniques. Zinc polymer is the first example of 1D coordination polymer constructed by tetra cationic zinc dimer as a secondary building unit in coordination polymer.

  17. Coordinated hybrid automatic repeat request

    Makki, Behrooz


    We develop a coordinated hybrid automatic repeat request (HARQ) approach. With the proposed scheme, if a user message is correctly decoded in the first HARQ rounds, its spectrum is allocated to other users, to improve the network outage probability and the users\\' fairness. The results, which are obtained for single- and multiple-antenna setups, demonstrate the efficiency of the proposed approach in different conditions. For instance, with a maximum of M retransmissions and single transmit/receive antennas, the diversity gain of a user increases from M to (J+1)(M-1)+1 where J is the number of users helping that user.

  18. Application coordination in pervasive systems

    Majuntke, Verena Elisabeth


    Pervasive applications are designed to support users in their daily life. For this purpose, applications interact with their environment, i.e. their context. They are able to adapt themselves to context changes or to explicitly change the context via actuators. If multiple applications are executed in the same context, interferences are likely to occur. To manage interferences, a coordination framework is presented in this thesis. Interferences are detected using a context model and information about applications' interaction with the context. The resolution of interference is achieved through

  19. Geometrical product specifications. Datums and coordinate systems

    Glukhov, V. I.; Ivleva, I. A.; Zlatkina, O. Y.


    The work is devoted to the relevant topic such as the technical products quality improvement due to the geometrical specifications accuracy. The research purpose is to ensure the quality indicators on the basis of the systematic approach to the values normalization and geometrical specifications accuracy in the workpiece coordinate systems in the process of design. To achieve the goal two tasks are completed such as the datum features classification according to the number of linear and angular freedom degrees constraints, called the datums informativeness, and the rectangular coordinate systems identification, materialized by workpiece datums sets. The datum features informativeness characterizes the datums functional purpose to limit product workpiece linear and angular degrees of freedom. The datum features informativeness numerically coincides with the kinematic pairs classes and couplings in mechanics. The datum features informativeness identifies the coordinate system without the location redundancy. Each coordinate plane of a rectangular coordinate system has different informativeness 3 + 2 + 1. Each coordinate axis also has different informativeness 4+2+Θ (zero). It is possible to establish the associated workpiece position with three linear and three angular coordinates relative to two axes with the informativeness 4 and 2. is higher, the more informativeness of the coordinate axis or a coordinate plane is, the higher is the linear and angular coordinates accuracy, the coordinate being plotted along the coordinate axis or plane. The systematic approach to the geometrical products specifications positioning in coordinate systems is the scientific basis for a natural transition to the functional dimensions of features position - coordinating dimensions and the size of the features form - feature dimensions of two measures: linear and angular ones. The products technical quality improving is possible due to the coordinate systems introduction materialized by

  20. Attitude coordination of multiple spacecraft for space debris surveillance

    Felicetti, Leonard; Emami, M. Reza


    This paper discusses the attitude coordination of a formation of multiple spacecraft for space debris surveillance. Off-the-shelf optical sensors and reaction wheels, with limited field of view and control torque, respectively, are considered to be used onboard the spacecraft for performing the required attitude maneuvers to detect and track space debris. The sequence of attitude commands are planned by a proposed algorithm, which allows for a dynamic team formation, as well as performing suitable maneuvers to eventually point towards the same debris. A control scheme based on the nonlinear state dependent Riccati equation is designed and applied to the space debris surveillance mission scenario, and its performance is compared with those of the classic linear quadratic regulator and quaternion feedback proportional derivative controllers. The viability and performance of the coordination algorithm and the controllers are validated through numerical simulations.

  1. Global Materials Structure Search with Chemically Motivated Coordinates.

    Panosetti, Chiara; Krautgasser, Konstantin; Palagin, Dennis; Reuter, Karsten; Maurer, Reinhard J


    Identification of relevant reaction pathways in ever more complex composite materials and nanostructures poses a central challenge to computational materials discovery. Efficient global structure search, tailored to identify chemically relevant intermediates, could provide the necessary first-principles atomistic insight to enable a rational process design. In this work we modify a common feature of global geometry optimization schemes by employing automatically generated collective curvilinear coordinates. The similarity of these coordinates to molecular vibrations enhances the generation of chemically meaningful trial structures for covalently bound systems. In the application to hydrogenated Si clusters, we concomitantly observe a significantly increased efficiency in identifying low-energy structures and exploit it for an extensive sampling of potential products of silicon-cluster soft landing on Si(001) surfaces.

  2. Studies on the Coordination Polymer of Copper Electropolyurushiol


    The coordination polymer of copper electropolyurushiol(EPU-Cu2+) was obtained by the reaction of copper chloride with electropolyurushiol (EPU) in an isopropyl alcohol solution. The properties of EPU-Cu2+ were studied by means of ESR, FTIR, XPS, DMTA and TG-DTA.The results of AES show that the content of Cu2+ was 8.63%. The electric resistances of EPUCu2+ and EPU were determined to be 9.37×1010Ω and 7.90×1010Ω respectively. It was also ascertained that in EPU-Cu2+ each Cu2+ is coordinated with two units hydroxyl in EPU, making the EPU-Cu2+ cross-link further. As a result, the title polymer exhibits an insolubility in most of organic solutions, a higher glass transition temperature and thermal resistance.

  3. Ultrafast isomerization in a difluoroboryl-coordinated molecular switch

    Consani, Cristina; Berberich, Martin; Würthner, Frank; Brixner, Tobias


    Molecular switches based on light-induced isomerization cycles are promising materials for sensors and biomedical applications. Understanding the details of the isomerization photocycle and identifying the nuclear coordinates involved in the photoreaction are relevant topics. Here we characterize the cis → trans and trans → cis isomerization of a new type of BF2-coordinated azo-dye molecular switch by pump-probe spectroscopy. While cis → trans isomerization is ultrafast and proceeds via a conical intersection, the trans → cis photocycle is more complex and involves at least three reaction channels. Finally, we employ the vibrational wavepackets accompanying isomerization to infer information on the nuclear degrees of freedom involved in the photoreaction.

  4. Harmonic Vibrational Analysis in Delocalized Internal Coordinates.

    Jensen, Frank; Palmer, David S


    It is shown that a principal component analysis of a large set of internal coordinates can be used to define a nonredundant set of delocalized internal coordinates suitable for the calculation of harmonic vibrational normal modes. The selection of internal coordinates and the principal component analysis provide large degrees of freedom in extracting a nonredundant set of coordinates, and thus influence how the vibrational normal modes are described. It is shown that long-range coordinates may be especially suitable for describing low-frequency global deformation modes in proteins.

  5. Unpacking Coordination Benefits in Supply Networks

    Petrick, Irene J.; Maitland, Carleen; Pogrebnyakov, Nicolai


    This paper examines how coordination among firms in supply networks generates benefits in the short and long terms for firms. It focuses on information technology (IT) and process improvement coordination. Analysis was performed on quantitative and qualitative data from a sample of SMEs in plastics...... manufacturing in Pennsylvania. Results indicate that coordination on both IT and process improvement leads to short- and long-term benefits. These relationships were mediated by the adoption of innovations (when coordinating on IT) and access to new capabilities (in process improvement coordination......). These results extend the understanding of how participation in supply networks benefits individual firms....

  6. Ytterbium Coordination Polymer with Four Different Coordination Numbers: The First Structural Characterization of Lanthanide Phthalate Complex

    WAN,Yong-Hong(万永红); JIN,Lin-Pei(金林培); WANG,Ke-Zhi(王科志)


    The novel ytterbium coordination polymer is a two-dimensional framework in which the central metal ions have four different coordination numhers and form four kinds of coordination polyhedra. The four kinds of coordination polyhedra connect into infinite chains by sharing oxygen atoms

  7. D Coordinate Transformation Using Artificial Neural Networks

    Konakoglu, B.; Cakır, L.; Gökalp, E.


    Two coordinate systems used in Turkey, namely the ED50 (European Datum 1950) and ITRF96 (International Terrestrial Reference Frame 1996) coordinate systems. In most cases, it is necessary to conduct transformation from one coordinate system to another. The artificial neural network (ANN) is a new method for coordinate transformation. One of the biggest advantages of the ANN is that it can determine the relationship between two coordinate systems without a mathematical model. The aim of this study was to investigate the performances of three different ANN models (Feed Forward Back Propagation (FFBP), Cascade Forward Back Propagation (CFBP) and Radial Basis Function Neural Network (RBFNN)) with regard to 2D coordinate transformation. To do this, three data sets were used for the same study area, the city of Trabzon. The coordinates of data sets were measured in the ED50 and ITRF96 coordinate systems by using RTK-GPS technique. Performance of each transformation method was investigated by using the coordinate differences between the known and estimated coordinates. The results showed that the ANN algorithms can be used for 2D coordinate transformation in cases where optimum model parameters are selected.

  8. Coordination Polymers of Palladium Bridged by Carboxylate and Dimethylaminoalkylselenolate Ligands.

    Paluru, Dilip K; Dey, Sandip; Wadawale, Amey P; Bhuvanesh, Nattamai; Grupp, Anita; Kaim, Wolfgang; Jain, Vimal K


    Coordination polymers of palladium stabilized by dimethylaminoalkylselenolate and carboxylate ligands are reported. The reaction of [PdCl(SeCH2 CH2 NMe2 )]3 with AgOTf followed by treatment with sodium acetate afforded [Pd(0) Pd(II) 4 (SeCH2 CH2 NMe2 )3 (OAc)3 ](OTf)2 (1) in which one of the Pd atoms is in the zero oxidation state. In the absence of NaOAc, a tetranuclear complex, [Pd(II) 4 (SeCH2 CH2 NMe2 )4 (OTf)](OTf)3 (2), is isolated from the same reaction. Subsequent treatment with NaO2 CR afforded [Pd4 (SeCH2 CH2 NMe2 )4 (O2 CR)4 ] (R=tBu (3) and Ph (4)). The reaction of [PdCl(SeCH2 CH2 CH2 NMe2 )]2 with AgOTf and NaOAc yielded an ionic binuclear complex, [Pd(II) 2 (SeCH2 CH2 CH2 NMe2 )2 (OAc)](OTf) (5). These complexes have been characterized by NMR spectroscopy, crystal structures, and in some cases by X-ray photoelectron spectroscopy, cyclic voltammetry and mass spectrometry. Complexes 1 and 5 are associated through secondary interactions and coordinate bonds, respectively, to generate polymeric structures in the solid state. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Collaborative Supply Chain Planning and Coordination

    Wong, Chee Yew

    between the toy manufacturer and three European retailers. These three case studies provide evidences that the toy manufacturer and the retailers followed some particular patterns of planning coordination processes; they also practised some patterns of coordination behaviour during the coordination...... processes, particularly the behaviour of risk-taking/avoidance, conflict resolutions, and self-interest. All these lead to conclusion of five propositions or principles of supply chain coordination, and the theory of coordination process and behaviour. Combining the propositions of responsiveness......This thesis contains main results from an industrial PhD research in the areas of supply chain strategy, planning, and coordination. It applies the concepts of responsiveness and coordination to reduce mismatch of supply and demand, especially for a volatile and seasonal supply chain. It involves...

  10. Cognition in Action: the Interplay of Attention and Bimanual Coordination Dynamics

    Temprado, Jean-Jacques

    Studies on motor coordination and on attentional load have developed into separate fields of investigation, bringing out findings, methods, and theories in almost perfect isolation. Sitting at their intersection, this chapter addresses the issue of behavioral flexibility by investigating how intention modifies the stability of existing patterns of coordination between moving limbs. Moreover, it addresses the issue, largely ignored until now, of the attentional cost incurred by the Central Nervous System (CNS) in maintaining a coordination pattern at a given level of stability, in particular under different attentional priority requirements. The experimental paradigm adopted in this study provides an original mix of a classical measure of attentional load, namely, Reaction Time (RT), and of a dynamic approach to coordination, most suitable for characterizing the dynamic properties of coordinated behavior and behavioral change. This paradigm may constitute a first attempt to bridge the gap between a conceptualization of coordination in terms of information processing and another, more recent framework rooted in self-organization theories and dynamical systems models. The present studies establish that central cost and pattern stability covary, suggesting that bimanual coordination and the coupling activity ensured by the CNS to maintain such coordination bear on the same underlying dynamics.

  11. Computational analysis of the mechanism of chemical reactions in terms of reaction phases: hidden intermediates and hidden transition States.

    Kraka, Elfi; Cremer, Dieter


    Computational approaches to understanding chemical reaction mechanisms generally begin by establishing the relative energies of the starting materials, transition state, and products, that is, the stationary points on the potential energy surface of the reaction complex. Examining the intervening species via the intrinsic reaction coordinate (IRC) offers further insight into the fate of the reactants by delineating, step-by-step, the energetics involved along the reaction path between the stationary states. For a detailed analysis of the mechanism and dynamics of a chemical reaction, the reaction path Hamiltonian (RPH) and the united reaction valley approach (URVA) are an efficient combination. The chemical conversion of the reaction complex is reflected by the changes in the reaction path direction t(s) and reaction path curvature k(s), both expressed as a function of the path length s. This information can be used to partition the reaction path, and by this the reaction mechanism, of a chemical reaction into reaction phases describing chemically relevant changes of the reaction complex: (i) a contact phase characterized by van der Waals interactions, (ii) a preparation phase, in which the reactants prepare for the chemical processes, (iii) one or more transition state phases, in which the chemical processes of bond cleavage and bond formation take place, (iv) a product adjustment phase, and (v) a separation phase. In this Account, we examine mechanistic analysis with URVA in detail, focusing on recent theoretical insights (with a variety of reaction types) from our laboratories. Through the utilization of the concept of localized adiabatic vibrational modes that are associated with the internal coordinates, q(n)(s), of the reaction complex, the chemical character of each reaction phase can be identified via the adiabatic curvature coupling coefficients, A(n,s)(s). These quantities reveal whether a local adiabatic vibrational mode supports (A(n,s) > 0) or resists

  12. Applications of Bis(1-R-imidazol-2-yl)disulfides and Diselenides as Ligands for Main Group and Transition Metals: κ2-[N,N] Coordination, S-S Bond Cleavage and S-S/E-E (E = S, Se) Bond Metathesis Reactions

    Figueroa, Joshua S.; Yurkerwich, Kevin; Melnick, Jonathan; Buccella, Daniela; Parkin, Gerard


    Bis(1-R-imidazol-2-yl)disulfides, (mimR)2 (R = Ph, But), and diselenides, (seimMes)2, serve as bidentate [N,N]-donor ligands for main group and transition metals. For example, [κ2-(mimBut)2]MCl2 (M = Fe, Co, Ni, Zn), [κ2-(mimPh)2]MCl2 (M = Co, Zn), [κ2-(mimBut)2]CuX (X = Cl, I) and [κ2-(seimMes)2]MCl2 (M = Fe, Co, Ni) are obtained by treatment of (mimBut)2 or (seimMes)2 with the respective metal halide, and have been structurally characterized by X-ray diffraction. On the other hand, the zerovalent nickel complex Ni(PMe3)4 effects cleavage of the disulfide bond of (mimBut)2 to give square planar trans-Ni(PMe3)2(mimBut)2 in which the (mimBut) ligands coordinate via nitrogen rather than sulfur, a most uncommon coordination mode for this class of ligands. Although [κ2-(mimR)2]MCl2 (M = Fe, Co, Ni, Zn) are not subject to homolytic cleavage of the S-S bond because the tetravalent state is not readily accessible, the observation that [κ2-(mimPh)2]CoCl2 and [κ2-(mimBut)2]CoCl2 form an equilibrium mixture with the asymmetric disulfide [κ2-(mimPh)(mimBut)]CoCl2 indicates that S-S bond cleavage via another mechanism is possible. Likewise, metathesis between disulfide and diselenide ligands is observed in the formation of [κ2-(mimBut)(seimMes)]CoCl2 upon treatment of [κ2-(mimBut)2]CoCl2 with [κ2-(seimMes)2]CoCl2. PMID:17900186

  13. Motor coordination and visual information processing in high school students at risk of developmental coordination disorder: Two year follow-up study

    Rudolf Psotta


    Full Text Available BACKGROUND: Developmental coordination disorder (DCD in children is characterised by the execution being substantially below that expected given the individual's chronological age. This deficit can negatively affect the psychological and social development of the children and their academic achievements. A few studies provided the evidences on the persistence of impaired motor coordination up to the middle and older adolescence. Although DCD is the heterogeneous syndrome, it seems to be associated with problems in visual information processing. AIMS: The first aim of the study was to examine how a below-average motor coordination in the adolescents can be associated with visual information processing ability. Second aim was to reveal the short-term pathway of impaired motor coordination during adolescence and whether their persistence and reduction, respectively, could be associated with a level of visual information processing. METHODS: In the first phase of the study the below average motor coordination identified by the MABC-2 test (Henderson, Sugden, & Barnett, 2007 in the students of the high and vocational schools (n = 52 was analysed on its relation to the ability of visual information processing. This ability was assessed by the simple and choice reaction tests (FiTRO Reaction Check device. In the 2nd phase of the study the students with moderate and significant motor difficulties (n = 34 were reassessed two years after the initial testing to examine the changes in motor coordination and its potential association with a level of visual information processing. RESULTS: The below-average motor coordination correlated with the several measures of choice reaction with a determination of R2 9-15%, while a level of selective attention and physical growth of the adolescents were not the significant factors of motor skills. Of 34 adolescents 18 students demonstrated the reduction of motor difficulties in two years, and the persistence of the

  14. Impairments of social motor coordination in schizophrenia.

    Manuel Varlet

    Full Text Available It has been demonstrated that motor coordination of interacting people plays a crucial role in the success of social exchanges. Abnormal movements have been reported during interpersonal interactions of patients suffering from schizophrenia and a motor coordination breakdown could explain this social interaction deficit, which is one of the main and earliest features of the illness. Using the dynamical systems framework, the goal of the current study was (i to investigate whether social motor coordination is impaired in schizophrenia and (ii to determine the underlying perceptual or cognitive processes that may be affected. We examined intentional and unintentional social motor coordination in participants oscillating hand-held pendulums from the wrist. The control group consisted of twenty healthy participant pairs while the experimental group consisted of twenty participant pairs that included one participant suffering from schizophrenia. The results showed that unintentional social motor coordination was preserved while intentional social motor coordination was impaired. In intentional coordination, the schizophrenia group displayed coordination patterns that had lower stability and in which the patient never led the coordination. A coupled oscillator model suggests that the schizophrenia group coordination pattern was due to a decrease in the amount of available information together with a delay in information transmission. Our study thus identified relational motor signatures of schizophrenia and opens new perspectives for detecting the illness and improving social interactions of patients.

  15. Medicaid Managed Care Structures and Care Coordination.

    Gilchrist-Scott, Douglas H; Feinstein, James A; Agrawal, Rishi


    Child enrollment in Medicaid managed care (MMC) has expanded dramatically, primarily through state mandates. Care coordination is a key metric in MMC evaluation because it drives much of the proposed cost savings and may be associated with improved health outcomes and utilization. We evaluated the relationships between enrollment in 2 MMC structures, primary care case management (PCCM) and health maintenance organization (HMO) and access to and receipt of care coordination by children. Using data from the 2011/2012 National Survey of Children's Health and the Medicaid Statistical Information System state data mart, we conducted a retrospective, cross-sectional analysis of the relationships between fee-for-service, PCCM or HMO enrollment, and access to and receipt of care coordination. State-level univariate analyses and individual and state multilevel multivariable analyses evaluated correlations between MMC enrollment and care coordination, controlling for demographic characteristics and state financing levels. In univariate and multilevel multivariable analyses, the PCCM penetration rate was significantly associated with increased access to care coordination (adjusted odds ratio: 1.23, P = .034) and receipt of care coordination (adjusted odds ratio: 1.37, P = .02). The HMO penetration rate was significantly associated with lower access to care coordination (adjusted odds ratio: 0.85, P = .05) and receipt of care coordination (adjusted odds ratio: 0.71, P coordination may be more effective in PCCM than HMO structures. States should consider care coordination outcomes when structuring their Medicaid programs. Copyright © 2017 by the American Academy of Pediatrics.

  16. Coordination control of distributed systems

    Villa, Tiziano


    This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized control,  control with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

  17. Tree Formation Using Coordinate Method

    Monika Choudhary


    Full Text Available In this paper we are introducing a new method of tree formation, we propose a coordinate based method by which we can store and access tree structures. As we know in NLP, parsing is the most important module. The output of this module is generally parsed trees. Currently, TAG (Tree Adjoining Grammar is widely used grammar due to its linguistic and formal nature. It is simply tree generating system. The unit structure used in TAG is structured trees. So we used our new method to store trees where we worked on English to Hindi language. We worked on different sentences from English to Hindi, our method is the easiest way to manipulate tree. We have implemented within small corpus and for finite number of structures and further can be extended in future.

  18. PTPRR, cerebellum, and motor coordination.

    Schmitt, Ina; Bitoun, Emmanuelle; Manto, Mario


    Tyrosine phosphorylation is a powerful mechanism of modulation for proliferation, differentiation, and functioning of neurons. The protein products of the neuronal mouse gene PTPRR are physiological regulators of mitogen-activated protein kinase (MAPK) activities. PTPRR(-/-) mice display deficits of motor coordination and balance skills. PTPRR gene orthologues are found in many vertebrates. Recent observations suggest that the human episodic ataxia 2 (EA2) and spinocerebellar ataxia types 6 (SCA6), 12 (SCA12), and 14 (SCA14) might be associated with impaired phosphorylation levels of cerebellum calcium channels and receptors. The concept that MAPK signaling is a key process in tuning synaptic plasticity in cerebellar circuits is now emerging, with numerous implications for understanding cerebellar functions and cerebellar disorders.

  19. Reactions of Dicyclopentadienyltitanium(III) Compounds with Carbon Monoxide

    Boer, E.J.M. de; Cate, L.C. ten; Staring, A.G.J.; Teuben, J.H.


    Reactions of Cp2TiR (R = Cl, C6F5, C6H5, o-CH3C6H4) with CO give two types of products: terminally coordinated adducts, Cp2Ti(R)CO, and insertion products, Cp2TiCOR, i.e. acyl compounds. The acyl ligand is η2-coordinated at the titanium atom. The preparations and properties of the compounds are

  20. Coordination Complexes as Catalysts: The Oxidation of Anthracene by Hydrogen Peroxide in the Presence of VO(acac)[subscript 2

    Charleton, Kimberly D. M.; Prokopchuk, Ernest M.


    A laboratory experiment aimed at students who are studying coordination chemistry of transition-metal complexes is described. A simple vanadyl acetylacetonate complex can be used as a catalyst in the hydrogen peroxide oxidation of anthracene to produce anthraquinone. The reaction can be performed under a variety of reaction conditions, ideally by…

  1. Catalysis of Photochemical Reactions.

    Albini, A.


    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  2. Advances in Solid-State Transformations of Coordination Bonds: From the Ball Mill to the Aging Chamber

    Cristina Mottillo


    Full Text Available Controlling the formation of coordination bonds is pivotal to the development of a plethora of functional metal-organic materials, ranging from coordination polymers, metal-organic frameworks (MOFs to metallodrugs. The interest in and commercialization of such materials has created a need for more efficient, environmentally-friendly routes for making coordination bonds. Solid-state coordination chemistry is a versatile greener alternative to conventional synthesis, offering quantitative yields, enhanced stoichiometric and topological selectivity, access to a wider range of precursors, as well as to molecules and materials not readily accessible in solution or solvothermally. With a focus on mechanochemical, thermochemical and “accelerated aging” approaches to coordination polymers, including pharmaceutically-relevant materials and microporous MOFs, this review highlights the recent advances in solid-state coordination chemistry and techniques for understanding the underlying reaction mechanisms.

  3. Observing joint action: Coordination creates commitment.

    Michael, John; Sebanz, Natalie; Knoblich, Günther


    Previous research has shown that interpersonal coordination enhances pro-social attitudes and behavior. Here, we extend this research by investigating whether the degree of coordination observed in a joint action enhances the perception of individuals' commitment to the joint action. In four experiments, participants viewed videos of joint actions. In the low coordination condition, two agents made independent individual contributions to a joint action. In the high coordination condition, the individual contributions were tightly linked. Participants judged whether and for how long the observed agents would resist a tempting outside option and remain engaged in the joint action. The results showed that participants were more likely to expect agents to resist outside options when observing joint actions with a high degree of coordination. This indicates that observing interpersonal coordination is sufficient to enhance the perception of commitment to joint action. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Control coordination abilities in shock combat sports

    Natalya Boychenko


    Full Text Available Purpose: optimize the process control level of coordination abilities in martial arts. Material and Methods: analysis and compilation of scientific and methodological literature, interviews with coaches of drum martial arts, video analysis techniques, teacher observations. Results: identified specific types of coordination abilities in shock combat sports. Pod branny and offered specific and nonspecific tests to monitor the level of species athletes coordination abilities. Conclusion: it is determined that in order to achieve victory in the fight martial artists to navigate the space to be able to assess and manage dynamic and spatio-temporal parameters of movements, maintain balance, have a high coordination of movements. The proposed tests to monitor species coordination abilities athletes allow an objective assessment of not only the overall level of coordination, and the level of specific types of manifestations of this ability.

  5. Characteristics of Trivalent Lanthanides in Coordination Chemistry

    Xue Dongfeng(薛冬峰); Zuo Sen(左森); Henryk Ratajczak


    Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativity, bond valence parameter, bond length and lanthanide coordination number in these complexes are generally found , which show that for each trivalent lanthanide cation all calculated parameters may well be correlated with its coordination number in their coordination complexes. Specifically,32 new data for the bond valence parameter are first calculated in this work.An approximate linear relationship between the Ln-O bond valence parameter and the coordination number of Ln3+ is obtained.The Ln-O bond length increases with the increase in the lanthanide coordination number.The difference of electronegative values decreases with the increase in the lanthanide coordination number.

  6. [Allergic reactions to transfusion].

    Hergon, E; Paitre, M L; Coeffic, B; Piard, N; Bidet, J M


    Frequent allergic reactions following transfusion are observed. Usually, they are benign but sometimes we observe severe allergic reactions. Adverse reactions may be brought about by least two mechanisms. First, immediate-type hypersensibility reactions due to IgE. Secondly, anaphylactic-type reactions due to interaction between transfused IgA and class specific anti IgA in the recipient's plasma. They are characterized by their severest form (anaphylactic shock). The frequency of severe reactions following the transfusion blood plasma is very low. These transfusion reactions are complement-mediated and kinins-mediated. Prevention of allergic reactions is necessary among blood donors and recipients.

  7. Dynamic pathways to mediate reactions buried in thermal fluctuations. I. Time-dependent normal form theory for multidimensional Langevin equation.

    Kawai, Shinnosuke; Komatsuzaki, Tamiki


    We present a novel theory which enables us to explore the mechanism of reaction selectivity and robust functions in complex systems persisting under thermal fluctuation. The theory constructs a nonlinear coordinate transformation so that the equation of motion for the new reaction coordinate is independent of the other nonreactive coordinates in the presence of thermal fluctuation. In this article we suppose that reacting systems subject to thermal noise are described by a multidimensional Langevin equation without a priori assumption for the form of potential. The reaction coordinate is composed not only of all the coordinates and velocities associated with the system (solute) but also of the random force exerted by the environment (solvent) with friction constants. The sign of the reaction coordinate at any instantaneous moment in the region of a saddle determines the fate of the reaction, i.e., whether the reaction will proceed through to the products or go back to the reactants. By assuming the statistical properties of the random force, one can know a priori a well-defined boundary of the reaction which separates the full position-velocity space in the saddle region into mainly reactive and mainly nonreactive regions even under thermal fluctuation. The analytical expression of the reaction coordinate provides the firm foundation on the mechanism of how and why reaction proceeds in thermal fluctuating environments.

  8. Increased coordination in public transport – which mechanisms are available?

    Sørensen, Claus Hedegaard; Longva, Frode


    After several years of New Public Management reforms within public transport, coordination seems to receive increased attention. With examples of actual as well as suggested changes taken from Denmark, Sweden and the UK the aim of the article is to analyse and classify the mechanisms utilized...... and suggested to increase coordination between core stakeholders within passenger railway services and bus services. Four distinctive mechanisms of coordination are suggested, namely organisational coordination, contractual coordination, partnership coordination and discursive coordination. Each coordination...

  9. بهینه سازی خواص تخته خرده چوب- سیمان ساخته شده از ساقه پنبه و خاک اره با ماده افزودنی کلرید کلسیم (CaCl2

    مرتضی ناظریان مرتضی ناظریان


    Full Text Available هدف از این پژوهش بررسی رفتار هیدراتاسیون و خواص مکانیکی تخته خرده چوب -سیمان ساخته شده ازساقه پنبه و صنوبر و نیز خاک اره، حاوی مواد افزودنی CaCl2 در نسبت‌های مختلف وزنیمی‌باشد. در ابتدا، زمان انعقاد خمیر سیمانی حاوی مقادیر مختلف ماده افزودنی CaCl2و ذرات چوبی و ساقه پنبهتعیین شد. همچنین اثر میزان ماده افزودنی CaCl2، نسبت وزنیذرات پنبه به خرده چوب صنوبر، و درصد خاک اره بر روی مقاومت خمشی، مدول خمشی و چسبندگی داخلیتخته خرده چوب-سیمان توسط روش سطح پاسخ مورد ارزیابی قرار گرفت. به‌منظوربهینه‌سازی خواص تخته‌ها، معادله مدل ریاضی (توابع پاسخ درجه دو توسط برنامه شبیه‌سازی کامپیوتری انجام گردید. نتایج نشان داد که مقادیر پیش‌بینی شده، انطباق مناسبی با مقادیر واقعی دارد (ضریب تبیینR2 برای مدول گسیختگی، مدول الاستیسیته و چسبندگی داخلی به‌ترتیب برابر 93/0، 90/0، 95/0 بوده‌اند. همچنین معلوم شد که روش سطح پاسخ می‌تواند به ‌طور موثر برای مدل‌سازی خواص تخته‌ها بکار رود. بر اساس نتایج بدست آمده، با کاربرد ساقه پنبه به صنوبر با نسبت وزنی 43:57 مدول گسیختگی، مدول الاستیسیته و چسبندگی داخلی به ‌میزان حداکثر خود ‌رسید. هم‌زمان استفاده از ماده افزودنی تا حد 5/4 درصد و خاک اره تا حد 9 درصدتاثیر مثبتی بر روی

  10. Managing interteam coordination within and between organizations

    de Vries, Thomas Arend


    To accomplish complex tasks and effectively respond to environmental contingencies, teams must coordinate task-related issues with other teams (i.e., interteam coordination). Regrettably, interteam coordination is often complicated by misunderstandings that can arise from differences in teams’ languages, routines, and goals. In this dissertation I examine organizational structures, team composition strategies, and individual team member characteristics that can help to overcome such difficult...

  11. Novel Coordination Chemistry of Aluminum Borohydride


    four different crystal shapes were identified under a microscope.  Super thin plates are not a preferred crystal shape for X-ray analysis. Anion ...coordination of various ligands. Previously we investigated an IL based upon the [Al(BH4)4]- anion . This material showed a much improved air and...moisture stability compared to ABH. Here we present research on the coordination of the cyanoborohydride anion (NCBH3-) with ABH. The coordination

  12. Convergence of barycentric coordinates to barycentric kernels

    Kosinka, Jiří


    We investigate the close correspondence between barycentric coordinates and barycentric kernels from the point of view of the limit process when finer and finer polygons converge to a smooth convex domain. We show that any barycentric kernel is the limit of a set of barycentric coordinates and prove that the convergence rate is quadratic. Our convergence analysis extends naturally to barycentric interpolants and mappings induced by barycentric coordinates and kernels. We verify our theoretical convergence results numerically on several examples.

  13. Stabilization of coordinated motion for underwater vehicles

    Fan Wu; Zhi-Yong Geng


    This paper presents a coordinating and stabilizing control law for a group of underwater vehicles with unstable dynamics. The coordinating law is derived from a potential that only depends on the relative configuration of the underwater vehicles. Being coordinated, the group behaves like one mechanical system with symmetry, and we focus on stabilizing a family of coordinated motions, called relative equilibria. The stabilizing law is derived using energy shaping to stabilize the relative equilibria which involve each vehicle translating along its longest (unstable) axis without spinning,while maintaining a relative configuration within the group.The proposed control law is physically motivated and avoids the linearization or cancellation of nonlinearities.

  14. Bisxantphos: stereoselective synthesis and coordination behaviour of a new class of cyclic double bridged diphosphines

    den Heeten, R.; Zuidema, E.; Lutz, M.; Spek, A.L.; van Leeuwen, P.W.N.M.; Kamer, P.C.J.


    A new class of cyclic double bridged diphosphine ligands was developed and the coordination properties are described. The reaction of 4,5-dilithioxanthene with dichlorophenylphosphine gave a cyclic double bridged diphosphine ligand based on two xanthene backbones (4) as a single stereoisomer. X-ray

  15. Solvent-free porous framework resulted from 3D entanglement of 1D zigzag coordination polymer

    Kole, Goutam Kumar Umar


    A solvent-free porous metal organic framework is constructed by the 3D entanglement of 1D zigzag coordination polymeric chains. The role of solvents and the effect of reaction conditions on such unique entanglement are addressed. © 2010 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

  16. Combining coordination and supramolecular chemistry for the formation of uranyl-organic hybrid materials

    Deifel, N. P.; Cahill, Christopher L.


    Three hybrid compounds have been synthesized through hydrothermal reactions of UO{sub 2}(NO{sub 3}){sub 2}·6H{sub 2}O with 4-halobenzoic acid (X = Cl, Br, I). The formation of these compounds utilizes a composite synthesis methodology that explicitly employs aspects of both coordination chemistry and supramolecular chemistry (namely halogen---halogen interactions).

  17. Haptic feedback helps bipedal coordination.

    Roelofsen, Eefje G J; Bosga, Jurjen; Rosenbaum, David A; Nijhuis-van der Sanden, Maria W G; Hullegie, Wim; van Cingel, Robert; Meulenbroek, Ruud G J


    The present study investigated whether special haptic or visual feedback would facilitate the coordination of in-phase, cyclical feet movements of different amplitudes. Seventeen healthy participants sat with their feet on sliding panels that were moved externally over the same or different amplitudes. The participants were asked to generate simultaneous knee flexion-extension movements, or to let their feet be dragged, resulting in reference foot displacements of 150 mm and experimental foot displacements of 150, 120, or 90 mm. Four types of feedback were given: (1) special haptic feedback, involving actively following the motions of the sliders manipulated by two confederates, (2) haptic feedback resulting from passive motion, (3) veridical visual feedback, and (4) enhanced visual feedback. Both with respect to amplitude assimilation effects, correlations and standard deviation of relative phase, the results showed that enhanced visual feedback did not facilitate bipedal independence, but haptic feedback with active movement did. Implications of the findings for movement rehabilitation contexts are discussed.

  18. New form of geodetic coordinate system taking two length quantity as coordinate parameters

    Yimin SHI; Ziyang ZHU; Yeming FAN


    A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic long-itude and latitude was proposed. The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters, but the two families of coordinate curves were still meridians and parallel circles. The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate. The formula for the latitudinal scale factor of length for geodetic parallel lines was derived, by which the obtained result conformed to that standard value calculated from geodetic latitude, and it is applicable in the range of 400 km from north to south. Therefore, it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters; and consequently, it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.

  19. Synthesis and characterization of five-coordinated indium amidinates

    Riahi, Yasaman


    The focus of this work is synthesis, characterization and exploring the reactivity of new indium amidinate compounds of the type R{sub 2}InX (R = R''NCR'NR''; R' = Ph, R'' = SiMe{sub 3}, iPr, dipp; X = Br, Cl) with the coordination number of five and R{sub 3}In (R = Me{sub 3}SiNCPhNSiMe{sub 3}) with the coordination number of six. By using amidinates as chelating ligands the electron deficiency of indium atom will be resolved. Additionally, by using different substituents the study of the different synthesized indium amidinates has become possible. The selected method for the synthesis allows the carbodiimides to react with organolithium compounds to get the corresponding lithium amidinates. Afterwards the resulting lithium amidinates take part in transmetalation reactions with InBr{sub 3} and InCl{sub 3}. The study of the reactivity of indium amidinate complexes including nucleophilic reactions as well as their reduction were also examined. Beside crystal structure analysis, nuclear magnetic resonance spectroscopy as well as elemental analysis has been applied to characterize the compounds.

  20. Diamond formation in the deep lower mantle: a high-pressure reaction of MgCO3 and SiO2

    Maeda, Fumiya; Ohtani, Eiji; Kamada, Seiji; Sakamaki, Tatsuya; Hirao, Naohisa; Ohishi, Yasuo


    Diamond is an evidence for carbon existing in the deep Earth. Some diamonds are considered to have originated at various depth ranges from the mantle transition zone to the lower mantle. These diamonds are expected to carry significant information about the deep Earth. Here, we determined the phase relations in the MgCO3-SiO2 system up to 152 GPa and 3,100 K using a double sided laser-heated diamond anvil cell combined with in situ synchrotron X-ray diffraction. MgCO3 transforms from magnesite to the high-pressure polymorph of MgCO3, phase II, above 80 GPa. A reaction between MgCO3 phase II and SiO2 (CaCl2-type SiO2 or seifertite) to form diamond and MgSiO3 (bridgmanite or post-perovsktite) was identified in the deep lower mantle conditions. These observations suggested that the reaction of the MgCO3 phase II with SiO2 causes formation of super-deep diamond in cold slabs descending into the deep lower mantle. PMID:28084421