关于Gibbs函数变关系式引出的探讨

本文推荐陈林根编著的《工程化学》对化学热力学基本公式△G=△H-T△S的引出方法,试探基础教学的改革。     

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.     

Responses of practicing psychologists to a web site developed to promote empirically supported treatments.

Increased adoption of empirically supported treatments (ESTs) has been hindered in part by inadequate and inconvenient access to EST information and training. To improve diffusion of ESTs, the authors developed a Web application to provide practitioners with concise information by disorder on ESTs. The resulting site, therapyadvisor.com, was evaluated by 239 practicing psychologists to assess the usefulness of the site and explore possible interactions of EST attitudes on ratings of usefulness and impact. Two thirds of participants indicated using ESTs in practice, and limited time and resources were cited as primary barriers to EST adoption. The Web application was rated positively by most participants and was reported to increase awareness of and commitment to try ESTs among approximately 60% of participants. The results of this project support the feasibility of a Web application to increase diffusion and promote further adoption of ESTs. Technological and e-learning advances are promising directions for encouraging the adoption of ESTs specifically and evidence-based practice generally, particularly among busy practitioners who have inadequate time and resources for more traditional forms of dissemination and training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validation of a Method of Determination of Apparent Diffusivity Versus Composition in Solids

A method is presented for computing the values of apparent diffusivity in solids with respect to the concentration of the diffusing substance (water or sodium chloride). This method does not require any assumption upon the mathematical relationship between diffusivity and concentration. It can be applied to experimental measurements of local concentration versus position within the solid (profiles) with relatively few measurements (circa 10) and a mathematical smoothing of the experimental data by using an artificial neural network model. The method was first validated on simulated data obtained by using a constant diffusivity value and on experimental profiles when the relation between diffusivity and concentration was given. It was then applied to original experimental moisture profiles obtained by putting gelatin gels with different initial moisture contents into contact for up to 14 days. The method was also successfully applied to five sets of experimental moisture and sodium chloride profiles taken from the literature and obtained from different food products. Apparent diffusivities calculated by our method were found in agreement with those obtained by authors using different numerical methods to compute the diffusivity values.     

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。     

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)     

以不同PAN系炭纤维布制备燃料电池气体扩散层之研究

采用石墨化PAN系炭纤维布制备了高分子电解质燃料电池气体扩散层。通过电学实验、X-ray绕射与元素分析考察了所制气体扩散层的性能。结果表明：随热处理温度的升高，气体扩散层的电阻率降低，L2增加，d（x）2减小。高温处理后的炭纤维布作为高分子电解质燃料电池气体扩散层显示了较高的电池效能。     

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.     

聚酰亚胺渗透汽化膜的研究(Ⅰ)膜的制备和结构对动态吸附特性的影响

以2种二酐，3种二胺为单体，两步法制备了6种不同结构的聚酰亚胺均质膜，通过红外光谱和元素分析证实了其重复单元的分子结构，测定了这几种膜的物理性质和对水蒸气的动态吸附性能，并计算出其反常扩散指数dw。实验表明，随着聚合物二胺单元分子结构的变化，按MDA、ODA、PDA的顺序，密度逐渐变大，链间距逐渐减小，链堆砌变得紧密，水蒸气在膜中的吸附和扩散也变慢，并出现从正常扩散到反常扩散的过渡现象。