Semiempirical study on the valences of Cu and bond covalency in Y1-xCaxBa2Cu3O6+y

The valences of Cu and bond covalencies in Y1-xCaxBa2Cu3O6+y, have been investigated using complex chemical bond theory, This theory is the generalization of Phillips, Van Vechten, Levine, and Tanaka's scheme. The results indicate that the valences of Cu(1) and Cu(2) in our calculation agree well with those obtained by the bond valence sum method. The valences of Cu(1) and Cu(2) in our calculation also suggest that the holes introduced by Ca substitution only reside in CuO2 planes and there is a competing mechanism for the hole density in CuO2 planes between,Ca doping and oxygen depletion. These conclusions are in satisfactory agreement with experiments. The calculated ordering of covalencies is Cu(1)-O(4)>Cu(1)-O(1)>Cu(2)-O(2,3)>Cu(2)-O(1)>Ca-O>Y-O similar to Ba-O, regardless of the Ca doping level and oxygen content. [S0163-1829(98)03325-6].

Synthesis and crystal structure of aluminium complex with 3-hydroxyflavone

[Al(C15H9O3)(3)](2) . 2CHCl(3) . 8H(2)O was synthesized, and its crystal structure was determined. It belongs to trigonal system, R3, a=b=1. 655 8(3) nm, c=3. 646 5(20) nm, alpha = beta = 90 degrees, gamma = 120 degrees, V = 8. 656 08(0. 005 86) nm(3). D-c = 1.45 g/cm(3), mu(Mo K alpha) = 3. 20 cm(-1), F (000) = 3 924. The crystal structure was solved by Patterson and Fourier techniques, and refined by a block-diagonal least-squares method. A total of 3 737 independent intensity data were collected, of which 1 033 with I greater than or equal to 3 sigma(I-0) were observed, R = 0. 091 8, Rw=0. 091 8. Al3+ ion was 6-coordinated, bound to six oxygen atoms from three 3-hydroxyflavones to form a distortional coordination octahedron.

A ZINDO-SOS study on the nonlinear second-order optical properties of substituted silanes series molecules

On the basis of ZINDO methods,according to the sum - over - states( SOS) expression, we divise the program for the calculation of nonlinear second - order optical susceptibilities beta(ijk) and study how the different substituents on the phenyl ring attached to the atom silicon influence or; the nonlinear second - order optical properties for substituted silanes series molecules. The property of (CH3)(3)Si is Studied particularly. The effect of length of silica chains on the calculated beta values is studied too. The regularity summarized from calculated results has been explained micromechanically.

Study on computer perception of topological symmetry

A new algorithm for computer perception of topological symmetry is proposed. A node library containing various kinds of nodes is built, and the index number of the library is used as initial atom class identifier (CI) to discriminate the different types of non-hydrogen atoms. The path index (PI) and ringindex (RI) are calculated from the CI, and the global topological enviroment is defined as the sum of PIs and RIs. The topological symmetry can be detected by the iterative calculation of the global topological enviroment.

SYNTHESIS AND X-RAY STRUCTURE OF A SEMICONDUCTING ORGANOMETALLIC SALT [FECP(TOL)](2)[NI(MNT)(2)]

The compound [FeCp(Tol)](2)[Ni(mnt)(2)] has been prepared from [FeCp(Tol)]AlCl4 and Na-2[Ni(mnt)(2)]. This new organometallic radical ionic salt has been characterized by elemental analysis, IR, H-1 NMR and mass spectroscopy. The X-ray structure of the compound shows there are segregated cation and anion stacks in the perpendicular directions, The molecular anions form a zig-zag stacking along the b axis, and between every two neighbouring anion planes a methyl group of the cation is inserted. This gives rise to a long spacing of 6.87 Angstrom, between the anion planes. The cations stack along the c axis, with the closest spacing of 3.457 Angstrom between the cyclopentadienyl plane and the neighbouring toluene plane, which is shorter than the sum of Van der Wall's radii. Conductivity measurements showed the compound as a semiconductor with a room temperature conductivity of 1.6 X 10(-4) Scm(-1).

THE GENERAL AN INDEX AND ITS APPLICATION .4. THE APPLICATION OF GENERAL AN INDEX TO HYDROCARBONS

The general a(N) index (GAI) was used to characterize the cis, trans isomers of hydrocarbons. The best one-variable equations were obtained with GAI for several physicochemical properties of seven pairs of olefin cis, trans isomers. The linear correlation coefficients are in the range of 0.975 to 0.997. GAI was also compared with the other five topological indices, Randic connectivity index chi, Wiener number W, Hosoya index Z, the average distance sum connectivity J proposed by Balaban and a(N) index introduced by Yang, in correlating with the octane number (MON) of heptanes and octanes.

A nonlinear model for assessing multiple probabilistic risks: A case study in South five-island of Changdao National Nature Reserve in China

Several methods for estimating the potential impacts caused by multiple probabilistic risks have been suggested. These existing methods mostly rely on the weight sum algorithm to address the need for integrated risk assessment. This paper develops a nonlinear model to perform such an assessment. The joint probability algorithm has been applied to the model development. An application of the developed model in South five-island of Changdao National Nature Reserve, China, combining remote sensing data and a GIS technique, provides a reasonable risk assessment. Based on the case study, we discuss the feasibility of the model. We propose that the model has the potential for use in identifying the regional primary stressor, investigating the most vulnerable habitat, and assessing the integrated impact of multiple stressors. (C) 2006 Elsevier Ltd. All rights reserved.

The potential importance of grazing to the fluxes of carbon dioxide and methane in an alpine wetland on the Qinghai-Tibetan Plateau

To assess the impact of livestock grazing on the emission of greenhouse gases from grazed wetlands, we examined biomass growth of plants, CO2 and CH4 fluxes under grazing and non-grazing conditions on the Qinghai-Tibetan Plateau wetland. After the grazing treatment for a period of about 3 months, net ecosystem CO2 uptake and aboveground biomass were significantly smaller, but ecosystem CH4 emissions were remarkably greater, under grazing conditions than under non-grazing conditions. Examination of the gas-transport system showed that the increased CH4 emissions resulted from mainly the increase of conductance in the gas-transport system of the grazed plants. The sum of global warming potential, which was estimated from the measured CO2 and CH4 fluxes, was 5.6- to 11.3-fold higher under grazing conditions than under non-grazing conditions. The results suggest that livestock grazing may increase the global warming potential of the alpine wetlands. (c) 2005 Elsevier Ltd. All rights reserved.

一种基于状态方差阵对角相似分解的UKF 算法

在强非线性和复杂性的系统下，普通对称采样UKF 算法存在稳定性问题。为此，本文提出了基于状态方差阵对角相似分解的UKF 算法来保证算法的状态方差阵半正定。同普通对称采样UKF 算法比较，该算法降低了对状态方差阵的正定性要求。仿真试验验证了该方法的有效性。

Global Translation Preferred Active Contour

具有全局平移优先属性的主动轮廓更适于目标跟踪。演化轮廓具有的全局平移优先性可以理解为沿轮廓的速度场具有相等的倾向。根据此思想,通过定义在曲线扰动集合上的新内积空间导出了一种简单,具有平移优先的梯度流。新的内积空间由于是通过向H0主动轮廓对应的內积空间引入曲线扰动的方差获得,所以此主动轮廓称为方差主动轮廓。方差主动轮廓是将H0主动轮廓与其对应的平均梯度流通过加权求和获得,而H1主动轮廓则是通过H0主动轮廓与特定类型的核函数进行卷积得到。因此方差主动轮廓实现时更简单和快速。最后给出了H0,H1和方差主动轮廓在频域与时域的分析。

面向VAL语言和机器人仿真和离线编程

本文将介绍一个面向VAL语言和机器人仿真和离线编程系统ROSOP（Robot Simulation and off-line programming system）。该系统是中科院沈阳自动化所结合国家863高技术课题（“智能机器在人系统仿真”和“双机器人协调工作实验系统”），为两个PUMA机器人双手协调工作的研究而开发研制的。本文将主要讨论如下内容：● 系统总体结构和数据结构。● 3D交互式机器人及环境CAD建模。● VAL语言的离线编程和示数。● 3D图形动画仿真和碰撞检测。● Sum-3工作站开发环境及人机交互技术。

自治式移动车路标识别系统

路标识别是自治式移动车（ALV）视觉系统的一个重要组成部分，它能校正内部导航系统的定位误差，引导ALV沿正确的行驶。本文给出了一种路标识别系统结构，并对系统各模块做了较为详尽的阐述。该系统是预测驱动，基于知识的分割识别系统，在模型匹配的识别方法中引入大量的有关地图和路标的先验知识。给出ALV的近似位置，该系统首先根据地图知识预测是否有路标存在并对可能出现的路标，预测其路标模型。然后对图像进行分割处理，抽取符号特征，得到图像模型。最后将图像模型与预测的路标模型相匹配，验证预测的正确性，给出识别结果。该系统的主要特点是：1）地图和路标的先验知识都以显式的形式表示，集中存于知识库中，知识库具有良好的人机接口。2）在面向目标的特征抽取过程中，引入大量的关于路标的先验知识，对不同类型的路标，用不同的模块完成特征抽取。3）用证据累积与空间推理实现匹配，其中证据累积由启发式贝叶斯匹配器完成。即使在图像模型与路标模型有一定差异的情况下，仍能很好地完成识别任务。该系统己在VICOM彩色图像处理系统和sum-3工作站上用C语言实现。目前，能对二类路标进行成功的识别。本文给出了实验结果及分析。

成批生产计划调度的集成建模与优化

针对多品种批量生产类型,建立了调度约束的生产计划与调度集成优化模型。模型的目标函数是使总调整费用、库存费用及生产费用之和最小,约束函数包括库存平衡约束和生产能力约束,同时考虑了调度约束,即工序顺序约束和工件在单机上的加工能力约束,保证了计划可行性。该模型为两层混合整数规划模型,对其求解综合运用了遗传算法和启发式规则,提出了混合启发式求解算法。最后,针对某机床厂多品种批量生产类型车间进行了实例应用,对车间零件月份作业计划进行分解,得到各工段单元零件周作业计划,确定了零件各周生产批量与投产顺序。

承德公路隧道围岩分级与塌方机理分析

During tunnel constriction the classification of rock mass is widely used in tunnel design and construction. Moreover it offers the base information about tunnel investment and security. The quick classification of rock mass is very important for not delaying tunnel construction. Nowadays the tunnel engineers usually use initial survey files which are obtained by probe drilling to design a tunnel. It brings the problem that initial surrounding rock classification is usually much different from the real condition during the tunnel construction. Because initial surrounding rock lack credibility, it need us to make real time surrounding rock classification during the tunnel construction, and feed back the result to designers and constructors. Therefore, to find a quick wall rock classification method is very important not only for the time limit for a project but also for not delaying tunnel construction. Not all but many tunnels and underground constructions do suffer form collapse during the period of construction. Although accidental collapse in a large project in civil and geotechnical engineering sometimes appears to be a local event, if it occurred, it can bring about casualties, disrupted，production, construction delay, environmental damage, capital cost etc，therefore, it has been a difficult problem ,both in theory and in practice, establishing how to prevent underground structures form collapse and how to handle such an event in case in occurs. It is important to develop effective solutions and technical measures to prevent and control the collapse. According to the tunnel collapse occurred in Cheng De this paper analyze the main collapse mechanism leading to tunnel collapse and summon up the disposal method when collapse happened. It may be useful for tunnel construction in Cheng De in future. This paper is base on tunnel surrounding rock classification and tunnel support tasks during the tunnel construction in Cheng De area. It aims at solving 4 important problems in tunnel design and construction. 1) The relationship between rock rebound strength and rock single axle compression strength. First we go to the face wall and do rebound test on the tunnel face, then we chose some pieces of rock and do point loading test. Form the tests record we try to find the relationship between rock rebound strength and rock single axle compression strength. 2) The relationship between the value [BQ] and the value Q. First in order to obtain the information of rock character, rock strength, degree of weathering, the structure of rock mass, the joint condition, underground water condition and so on, we go to the tunnel face to do field investigation. And then we use two kinds of rock classification method to make surrounding rock classification. Base on the works above, finally we analyze the relationship between the value [BQ] and the value Q. 3) Sum up the mechanism leading to tunnel collapse and it disposal method in Cheng De area According to the tunnel collapse occurred in Cheng De this paper analyze the main reasons leading to the tunnel collapse and sum up the disposal method when collapse happened. 4) Obtain the properties of steel frame grid by numerical simulation. First we establish the 3D numeral model of steel frame grid by ADINA, and then find the mechanics properties by numerical simulation in ADINA. Second Based on the rock mass geological structure model, we established steel frame grid numeral model which is installed in the tunnel by FLAC3D and simulated the progress of tunnel construction. We hope that the support effect in tunnel can be evaluated from the numerical simulation.

井间地震速度层析成像方法与软件系统

Crosshole Seismic tomography has been broadly studied and applied in the fields of resource exploration and engineering exploration because of its special observing manner and better resolution than normal seismic exploration. This thesis will state the theory and method of Crosshole Seismic tomography. Basing on the previous studies，the thesis studied the initial velocity model，ray-tracing method, and developed the three-dimension tomography software. All the cells that a ray passes through are of the same velocities if the paths from transmitters to receivers are straight. The cells that the each ray passes through are recorded, and rays that pass through each cell are calculated. The ray average velocity which passes through a cell is set as the cell velocity. Analogously we can make a initial node velocity model because the velocity sum is calculated on the all cells which own to a certain node, and the cell number is summed about each nodes，the ratio of the velocity sum to the all cells number is set as the node velocity. The inversion result from the initial node velocity model is better than that of the average velocity model. Ray-bending and Shortest Path for Rays (SPR) have shortcomings and limitations respectively. Using crooked rays obtained from SPR rather than straight lines as the starting point can not only avoid ray bending converging to the local minimum travel time path, but also settle the no smooth ray problem obtained by SPR. The hybrid method costs much computation time, which is roughly equal to the time that SPR expends. The Delphi development tool based on the Object Pascal language standard has an advantage of object-oriented. TDTOM (Three Dimensions Tomography) was developed by using Delphi from the DOS version. Improvement on the part of inversion was made, which bring faster convergence velocity. TDTOM can be used to do velocity tomography from the first arrival travel time of the seismic wave, and it has the good qualities of friendly user interface and convenient operation. TDTOM is used to reconstruct the velocity image for a set of crosshole data from Karamay Oil Field. The geological explanation is then given by comparing the inversion effects of different ray-tracing methods. High velocity zones mean the cover of oil reservoir, and low velocity zones correspond to the reservoir or the steam flooding layer.