Calculation of second virial coefficients and gaseous viscosities of the refrigerants HFC-32 (CH2 F2), HFC-23 (CHF3), and HCFC-22 (CHC1F2)

The second virial coefficients of refrigerants HFC-32 (CH₂F₂), HFC-23 (CHF₃), and HCFC-22 (CHC1F₂) have been correlated on the bisis of site site model potential and have been compared with experimental results. The molecular interactions consisted of repulsion dispersion and electrostatic parts. From the site site potentials adjusted to the experimental second virial coefficients, spherically averaged potentials have been determined and a subsequent calculation of gaseous viscosity has been carried out. Agreement between measured and calculated values of second virial coellicients and gaseous viscosity is satisfactory. Calculated values of second virial coefficients and gaseous viscosity beyond available experimental data, therefore. can be assumed as a reliable extrapolation to lower and higher temperatures.     

我国天然彩棉的研发现状及发展趋势

对天然彩棉的历史、纤维特点、纤维的形态结构及性能作了简要介绍，重点介绍了我国彩棉的研发现状及研发中亟待解决的瓶颈问题，最后对彩棉在我国的发展前景进行了展望。     

浮基多刚体系统动力分析

引入浮体势流流固耦合理论和多刚体力学的凯恩方法对浮基多刚体系统进行动力分析。考虑入射规则波的影响和上部作业物体进行回转作业、升降作业的影响，建立了浮基多刚体系统的运动方程，讨论了浮基多刚体系统运动方程在三类情况下的求解途径。     

Response coding and visuomotor transformation in the Simon task: The role of action goals.

Manual responses can be defined by differing response parameters. Any of them may generate a Simon effect. For all those response parameters, the same implementation of the Simon effect (in terms of subserving mechanism) is assumed. In 3 experiments, subjects had to respond with either fingers or sticks. Temporal properties of the Simon effect changed with response parameters relevant in a task. The Simon effect for manual responses decayed. For stick responses, in which the action goal differed from the anatomical mapping of the acting hand, a sustained Simon effect was observed. However, if the action goal for stick responses was not instrumental for selecting the correct response, the Simon effect decayed. The findings are consistent with the notion of different mechanisms involved in generating a Simon effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral and subjective effects of D-amphetamine and modafinil in healthy adults.

Modafinil is indicated for the management of excessive daytime sleepiness; however, recent studies have examined a broad range of potential uses. Given that clinical uses of modafinil may be expanding, this study compared modafinil and d-amphetamine effects on subjective and performance measures. Across 11 sessions, 11 healthy adults were tested after oral doses of placebo (5 sessions), modafinil (1.75 mg/kg, 3.50 mg/kg, or 7.00 mg/kg), and d-amphetamine (0.035 mg/kg, 0.070 mg/kg, 0.140 mg/kg) under double-blind, randomized conditions. Assessments of cognitive performance and subjective effects were completed before drug administration, 30 min after drug administration, and at hourly intervals after drug administration for 5 hr. Modafinil increased ratings on the Amphetamine and Morphine Benzedrine Group scales of the Addiction Research Center Inventory (ARCI) and increased ratings on the Vigor and Total Positive scales of the Profile of Mood States. d-Amphetamine increased visual analog ratings of feeling stimulated and liking the drug and increased ratings on the Morphine Benzedrine Group scale of the ARCI. Both medications significantly reduced visual analog scale ratings of feeling sleepy, and modafinil decreased ratings on the ARCI Pentobarbital-Chlorpromazine-Alcohol Group scale. Both medications sustained performance that deteriorated across time on the Sternberg Number Recognition Test. Modafinil also enhanced performance rate on the Digit-Symbol Substitution Task above baseline levels and increased response rate on the Repeated Acquisition of Response Sequences Task. These results suggest that modafinil engenders alerting effects and increases performance in healthy non-sleep-deprived individuals comparable with that of d-amphetamine. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Symmetric BEM formulations for 2-D steady-state and transit potential problems

This paper presents a new concept for symmetric boundary element method (SBEM) applicable to 2-D steady-state and transit potential problems. Two kinds of SBEM formulations are derived. Symmetry is obtained simply through matrix manipulation, and no hypersingularity appears. Therefore, SBEM is much easier than the traditional symmetric Galerkin BEM. Compared with the traditional asymmetric BEM, the present SBEM can reduce the computational cost for time domain problems only. However, when applied to BEM/FEM coupling procedure, SBEM can reduce the computational cost for both steady-state and time domain problems. Three numerical examples are included to illustrate the effectiveness and accuracy of the present formulations.     

集团变分法(CVM)及其在合金相图计算中的应用

介绍了集团变分法的集团概率变量、配置熵等统计分析的理论基础及Helmholtz自由能的描述模型.提出了巨势及相对化学势的几何分析理论.讨论了应用集团变分法和巨势分析理论进行相平衡计算的过程,并分析了同结构平衡相图计算的若干实例.     

视觉诱发脑电波的时变最优滤波估计

本文提出了一个自修正的非平稳信号模型,并设计了时变最优滤波器于视觉诱发脑电波 的估计.估计出的信号与原始信号的各波峰潜伏期严格保持一致,而波峰幅值略有衰减.给 出的仿真与实体试验结果都证明了本方法的有效性.     

关于气井产能、气田稳产特征和气区开采潜力的探讨

根据气田开发特点和国内外开发实践，对气田平均产能评价方法、开发速度与稳产的关系以及气区开采潜力等问题进行了探讨，以提高开发评价、开发建设及投资决策的科学性与可靠性，达到高效开发和稳定供气的目的。分析评价了国内外常用的6种气井产能评价方法，指出了其适用条件。利用中国、土库曼斯坦和俄罗斯部分开发历史较长的气田开发实例分析了开发速度与稳产的关系，结果表明四川裂缝系统稳产情况最好，而土库曼斯坦气田稳产关系最差。利用俄罗斯已枯竭老气区、正在开发的大型主力气区以及中国四川开采历史较长气区的开发实例，对气区开采潜力进行综合分析和探讨，认为在预测气田（或气区）的开发潜力、稳定供气水平和年限时，要全面评价、预计尚未探明储量的规模、质量、投产时间、投产顺序以及储量的可信度和可靠性，以降低开发决策的风险，提高中、长期开发规划的科学性。图5表2参10     

A BOUNDARY INTEGRAL EQUATION AND ITS NUMERICAL SOLUTION OF POTENTIAL FLOW AROUND SURFACE-IRREGULA-RITIES

In this paper,using complex functional theory,the authors turn the potentialflow around the surface irregularities in a pressure conduit and semi-infinite platforms intoDirichlet problem.Based on Schwarz formula and by the application of Plemelj's formula,theauthors change the problem into the integration of a Cauchy boundary integral equation in theflow plane through the substitution of variables.Using numerical integration,the authors obtainthe velocity distribution and pressure coefficient along surface irregularities and platforms.Thephysical concept of this method is clear,the convergent speed is rapid and the computative effi-ciency is high.The calculated values agree well with the measured results.It is an effective andsimple method in solving potential flow.