无界平面静电场的边界处理方法

研究用有限元法计算无界平面静电场时处理无界边界的方法，并指出了各种方法的应用范围．

世界商业中心东移

在人类历史长河中,中国第一次在世界平面上置身于难得的机遇中。 世界商业中心正向东移 在二战后不久,战败的日本在远东很快复兴,成为仅次于美国的“经济大国”。加上韩国、台湾、香港、新加坡成功地发展了出口工业,致使亚太地区与美国间的贸易总额在80年代中期第一次超过了欧美之间的数额。这意味着,太平洋已开始替代大西洋,至少与它并列作为世界商业中心的地区了。同时,在东亚作为自由港的香港也跟着形成了与伦敦、纽约并立的世界三大金融中心之地位。可是,随着中国经济的快速发展,真正能成为21世纪世界商业中心的将是上海。它将与伦敦、纽约在世界平面上形成三足并立局面。

线性规划问题的一个强多项式算法

本文通过求解关于参变量的约束不等式组的方法，确定边界解处的目标向量的唯一的射影子空间．根据这一子空间，或使目标函数值得到进一步优化，或证明目标函数值已达到最优．本算法为强多项式算法．

First-principles thermodynamics of metal-oxide surfaces andinterfaces:A case study review

An important step for achieving the knowledge-based design freedom on nano-and interfacial materials is attained by elucidating the related surface and interface thermodynamics from the first principles so as to allow engineering the microstructures for desired properties through smartly designing fabrication processing parameters.This is demonstrated for SnO2 nano-particle surfaces and also a technologically important Ag-SnO2 interface fabricated by in-situ internal oxidation.Based on defect thermodynamics,we first modeled and calculated the equilibrium surface and interface structures,and as well corresponding properties,as a function of the ambient temperature and oxygen partial pressure.A series of first principles energetics calculations were then performed to construct the equilibrium surface and interface phase diagrams,to describe the environment dependence of the microstructures and properties of the surfaces and interfaces during fabrication and service conditions.The use and potential application of these phase diagrams as a process design tool were suggested and discussed.

Improvement of pump-probe optical measurement technique using double moving stages

In order to improve the measurement precision and increase the reliability of the femtosecond laser transient thermoreflectance system, the relative optical path difference between pump and probe beams is prolonged, which can improve the fitting accuracy of the experimental data to the theoretical model. A modified experimental setup is devised with the pump path intercalated a moving stage identical to the one in the probe path, which extends the optical path difference of the probe beam relative to the pump beam from 4 to 8 ns. The measured results indicate that the uncertainty from the misalignment and divergence of both beams can be ignored when the last 4 ns experimental data are connected with those of the first 4 ns smoothly. The as-obtained thermal conductance of AI/Si and Cr/Si interfaces agrees well with the reported experimental values, which verifies the reliability of this modified version of this measurement.

Failure analysis study of railway draw-hook coupler

Failure analysis of railway draw-hook coupler was carried out.The nondestructive testing method was undertaken on some failed couplers in service to designate critical areas of a coupler.Draw-Hook coupler is used to connect with the same hook coupler or automatic coupler.The influence of each connection types on the coupler strength in this study was discussed.A numerical stress analysis using FEM was performed,and many approaches including critical plane approach were carried out on fatigue life prediction of coupler under different conditions.The results of the proposed fatigue criterion and fatigue life predictions,as well as static numerical analysis,are validated with experimental results.

Prediction of Pressure Gradient and Holdup in Small Eoetvoes Number Liquid-Liquid Segregated Flow

The segregated flow pattern, which occurs in a 26.1 mm diameter, horizontal, stainless steel test section, is investigated. Pressure gradient and in situ phase distribution data were obtained for different combinations of phase superficial velocities ranging from 0.05 m.s^-1 to 0,96 m.s^-1. For the current small Eoetvoes number liquid-liquid system （EOD=4.77）, the dominant effect of interfacial tension and wall-wetting properties of the liquids over the gravity is considered. The approach introduces the closure relationship for the case of turbulent flow m a rough pipe, and attempts to modify the two-fluid model to account for the curved interface. In present flow rates range, wave amplitudes were found small, while interfacial mixing was observed. An adjustable definition for hydraulic diame- ters of two fluids and interfacial friction factor is adopted. The predicted pressure gradient and in situ phase distribution data have been compared with present experimental data and those reported in the literature.

Modeling and optimization of unbalanced multi-stage logistic system

To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems.

Brownian Motion of a Test Particle with a Normal Classical Velocity in Spacetime with a Plane Boundary

We study the random motion of a charged test particle with a normal classical constant velocity in a spacetime with a perfectly reflecting plane boundary and calculate both the velocity and position dispersions of the test particle. Our results show that the dispersions in the normal direction are weakened while those in the parallel directions are strengthened as compared to the classical static case when the test particle classically moves away from the boundary. However, if the classical motion reverses its direction, then the dispersions in the normal direction are reinforced while those in the parallel directions get weakened.

Partition Equilibrium Between Charged Membrane and Single Electrolyte Aqueous Solution

Ionic partition equilibrium in charged membrane immersed in solution of single electrolyte with monovalence or multi-valence is systematically investigated and several expressions are established for determination of partition coefficients. On this basis, the effects of the ratio of membrane charge density to bulk electrolyte solution concentration, the charge sign and valence of electrolyte ions and the type of membrane on the partition equilibrium were analyzed and simulated within chosen parameters. It is revealed that ion partition is not related solely with the respective concentrations but also definitely with the concentration ratio of fixed group to bulk solution in addition to the charge sign and the valence. For a counterion, the partition coefficient increases with this ratio and the valence; while for a coion, the partition coefficient decreases with this ratio and the valence. The theoretical calculations were compared with the experimental data and a good agreement was observed.

An upper bound analysis of rolling process of non-bonded sandwich sheets

Rolling process of symmetrical non-bonded sandwich sheets was investigated by the method of upper bound. A deformation model was proposed and the mathematical relations of the velocity components were developed. The internal, shear and frictional power terms were derived and used in the upper bound model. Through the analysis, the rolling force, mean contact pressure and final thickness of each layer were determined. The validity of the proposed analytical model was discussed by comparing the theoretical predictions with the experimental data found in the literatures. Effects of various rolling conditions such as the flow stress ratio, initial thickness ratio of the raw sheets and total thickness reduction upon the rolling torque were analyzed. The accuracy of the developed analytical model was very high.

Local Measurement of Gas-Liquid Bubbly Flow with a Double-Sensor Probe

A double-sensor probe was used to measure local interfacial parameters of a gas-liquid bubbly flow in a horizontal tube. The parameters included void fraction, interfacial concentration, bubble size distribution, bubble frequency and bubble interface velocity. The authors paid special attention to the probe design and construction for minimizing measurement errors. Measures were also taken in the design of sensor ends for preventing corrosions in the flow. This is an effort to improve the current double-sensor probe technique to meet the ever-increasing needs to local parameter measurements in gas-liquid two-phase flows.

Composition Operators Mapping into the E(p,q) Spaces

Composition operators are used to study the E(p,q) spaces. The boundedness of these operators is also considered. The criteria for these operators to be bounded are given in terms of the Carleson measure.

Determining the hydrodynamic forces on a planing hull in steady motion

A combination of methods was developed that can determine hydrodynamic forces on a planing hull in steady motion.Firstly,a potential-based boundary-element method was used to calculate the hydrodynamic pressure,induced resistance and lift.Then the frictional resistance component was determined by the viscous boundary layer theory.Finally,a particular empirical technique was applied.to determine the region of upwash geometry and determine spray resistance.Case studies involving four models of Series 62 planing craft were run.These showed that the suggested method is efficient and capable,with results that are in good agreement with experimental measurements over a wide range of volumetric Froude numbers.

绘制非国有渔业养殖水域办证用图纸的探讨

应用手持GPS测量非国有渔业养殖水域,再利用Mapinfo地图软件制作平面图界至图,所绘图纸方位角、面积准确,达到《水域滩涂养殖证》办证要求。

Singular Values and Real Fixed Points of One Parameter Family of Function zbz/（bz-1）

The purpose of this paper is to study the singular values and real fixed points of one parameter family of function,fλ（z）=λab2/b2-1,fλ（0）=λ/lnb for λ∈R／{0},z∈C and b〉 0 except b = 1. It is found that the function fλ（z） has infinitely many singular values for all b 〉 0 except b = 1. It is also shown that, for 0 〈 b 〈 1, all the critical values of fλ（z） lie in the left half plane while, for b 〉 1, lie in the right half plane. Further, it is seen that all these critical values are outside the open disk centered at origin and having radius ｜λ/lnb｜for all b 〉 0 except b = 1. Moreover, the real fixed points of fλ （z） and their nature are investigated.

Performance of interface between TRC and existing concrete under a chloride dry-wet cycle environment

Textile-reinforced concrete(TRC)is suitable to repair and reinforce concrete structures in harsh environments.The performance of the interface between TRC and existing concrete is an important factor in determining the strengthening effect of TRC.In this paper,a double-sided shear test was performed to investigate the effects of the chloride dry-wet cycles on the average shear strength and slip at the interface between the TRC and existing concrete,also considering the existing concrete strength,bond length,textile layer and short-cut fiber arrangements.In addition,X-ray diffraction(XRD)technology was used to analyze the microscopic matter at the interface in the corrosive environment.The experimental results indicate that the interface performance between TRC and existing concrete would decrease with continued chloride dry-wet cycles.Compared with the specimen with a single layer of textile reinforcement,the specimens with two layers of textile with added PVA or AR-glass short-cut fibers could further improve the properties of the interface between the TRC layer and existing concrete.For the TRC with a single layer of textile,the average shear strength tended to decrease with increasing bond length.In addition,the strength grade of the existing concrete had a minor effect on the interface properties.

Research on Translation Gateway for IPv4/IPv6

In this paper, a model of translation gateway is proposed. The communications between IPv4 network and IPv6 network are realized by using the Microsoft intermediate driver technology in environment of Windows 2000.

A Study on the Usability of Semiotics in Graphic Design

Currently, The current flat design has become a mainstream approach is widely used in web design, computer and mobile phone systems, interface design. In graphic design, graphic symbol design is increasingly being taken seriously and use minimalist design symbols often appear in print design plane, PPT presentations, public areas, identity-oriented system like. This paper discusses the design of graphical symbols flat in graphic design use need to make the audience cognitive ability, graphic symbols standardized principles, design principles angles for effective information design to achieve efficient information communication. Materialized mostly graphic image symbols, and mostly flat graphic indicator; flat screen symbol by the proposed development materialized symbol interface evolved. Materialized the graphical interface and the graphical interface is flat coexist and cannot replace each other. During the design, the designer should be based on the advantages and disadvantages of the two styles complement each other interfaces, common graphical interface design services.

Microstructure and mechanical behavior of Ti/Cu/Ti laminated composites produced by corrugated and flat rolling

Ti/Cu/Ti laminated composites were fabricated by corrugated rolling(CR) and flat rolling(FR) method.Microstructure and mechanical properties of CR and FR laminated composites were investigated by scanning electron microscopy, numerical simulation methods, peel and tensile examinations. The effect of CR and FR was comparatively analyzed. The results showed that the CR and FR laminated composites exhibited different effective plastic strain distributions of the Ti layer and Cu layer at the interface. The recrystallization texture, prismatic texture and pyramidal texture were developed in the Ti layer by CR, while the R-Goss texture and shear texture were developed in the Cu layer by CR. The typical deformation texture components were developed in the Ti layer and Cu layer of FR laminated composites. The CR laminated composites had higher bond strength, tensile strength and ductility.