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91.
Comments on the article by C. E. Watkins et al (see record 1995-23048-001) on the practice of psychological assessment by clinical psychologists. According to Hunsley, their conclusion that the basic practice of assessment has changed little in the past 30 yrs is not warranted because of the nature of the survey data used. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
Human 11 beta-hydroxysteroid dehydrogenase-types 1 and 2 and human 15-hydroxyprostaglandin dehydrogenase belong to a large family of oxidoreductases that includes human dihydropteridine reductase and Streptomyces hydrogenans 20 beta-hydroxysteroid dehydrogenase, for which 3D structures are available. Almost all of these enzymes are either dimers or tetramers. The dimer interface of rat dihydropteridine reductase consists of alpha-helices E and F from each monomer arranged in a four alpha-helix bundle [Varughese et al. (1992) Proc. Natl. Acad. Sci. USA 89, 6080-6084]. Alpha-helix F contains tyrosine-146 and lysine-150, residues that are highly conserved in this protein superfamily and have been proposed to be at the catalytic site. We have examined the dimer interface between alpha-helix F in human and rat dihydropteridine reductase and Streptomyces hydrogenans 20 beta-hydroxysteroid dehydrogenase as well as modeled 3D structures of steroid and prostaglandin dehydrogenases and homologs for stabilizing interactions. We find a site in the middle of alpha-helix F that stabilizes the dimer. This anchor is adjacent to conserved lysine on alpha-helix F. Our analysis suggests that sequence variation in the anchor may be important in substrate specificity. 相似文献
93.
94.
A parameter-free geometric model for nuclear absorption is derived from microscopic theory. The expression for the absorption cross section in the eikonal approximation taken in integral form is separated into a geometric contribution, described by an energy-dependent effective radius, and two surface terms which are shown to cancel in an asymptotic series expansion. For collisions of light nuclei, an expression for the effective radius is derived using harmonic-oscillator nuclear density functions. A direct extension to heavy nuclei with Woods-Saxon densities is made by identifying the equivalent half density radius for the harmonic-oscillator functions. Coulomb corrections are incorporated and a simplified geometric form of the Bradt-Peters type obtained. Results spanning the energy range of 1 MeV/nucleon to 1 GeV/nucleon are presented. Good agreement with experimental results are obtained. 相似文献
95.
Carlston Donal E.; Skowronski John J.; Sparks Cheri 《Canadian Metallurgical Quarterly》1995,69(3):420
Five experiments based on Carlston and Skowronski's (1994) relearning paradigm suggest that people spontaneously derive trait knowledge about actors from behaviors but that this knowledge may reflect either explicit trait inference processes or implicit actor–trait associations. Experiments 1 and 2 found that inference-instructed and control Ss showed equivalent savings in subsequent efforts to learn actor–trait pairs but not when instructed Ss initially inferred the wrong trait. Experiment 3 showed that savings were equivalent for stimuli from different sources, and Experiment 4 showed that savings effects persisted even when the target was only incidentally associated with a stimulus behavior. Finally, Experiment 5 suggests that after several days, even explicit trait inferences can become inaccessible to intentional retrieval, although the earlier experiments show that they continue to exert an implicit effect on learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
William N. Gill Rajiv M. Ginde John Verhoeven 《Chemical Engineering Communications》1993,124(1):49-56
The linear theory of Pearson (1958) and Nield (1964) is modified here to study liquid tin and include the finite thermal resistances of the bounding layers of boron nitride, copper and air (∼10-2 torr) in the experiments of Ginde et al. (1989). The magnitude of the ΔTc across the layer of liquid tin required for the onset of convection depends on the ratios of the thermal conductivities and thicknesses of the supporting layers of boron nitride and copper to those of the tin.
According to our theory surface tension contributes more than buoyancy to the instability observed experimentally. The critical ΔTc observed required for the onset of convection in the layer of tin, is up to 25% lower than that predicted, which shows the layer is less stable than the theory indicates. Thus the surface of the tin was uncontaminated, or a significantly larger observed critical ΔTc would be expected.
The boundary condition on the thermal fluctuations at the base of the supporting layer of copper does not appear to be important in these experiments. However, the thermal resistance of the boron nitride would have to be assumed to be unrealistically large to obtain agreement within experimental error with the theory. 相似文献
According to our theory surface tension contributes more than buoyancy to the instability observed experimentally. The critical ΔTc observed required for the onset of convection in the layer of tin, is up to 25% lower than that predicted, which shows the layer is less stable than the theory indicates. Thus the surface of the tin was uncontaminated, or a significantly larger observed critical ΔTc would be expected.
The boundary condition on the thermal fluctuations at the base of the supporting layer of copper does not appear to be important in these experiments. However, the thermal resistance of the boron nitride would have to be assumed to be unrealistically large to obtain agreement within experimental error with the theory. 相似文献
97.
Feedback provided to Ss and 3rd parties from intra- and extramural investigators following the completion of research involving an agency's clients or staff is described. Ss were from the division of a public health department that provides mental health and substance abuse services in a city with 740,000 people. The division's research requirements include submission of annual progress reports and final reports. Of 135 studies conducted over 12 yrs, annual reports were received from 37% of investigators, and final reports from 30%. There were no significant differences based on investigator discipline or affiliation. Professional and ethical implications are discussed, including adequacy of professional training, the need for mechanisms to ensure compliance with ethical standards, the obligations of clinic directors, and the impact on public academic liaison programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
随着信息产业的飞速发展,高频信号设备,如高速计算机、移动电话、卫星通信等,都已从兆赫频段扩展到千兆赫,这就意味着对它们所用的微波电路基板提出了更高的要求.长期以来,高频微波基板几乎没有越出使用聚四氟乙烯的老传统,但是,它有若干缺点玻璃化温度低,故刚性差;加工复杂,故成本高;金属化孔镀层与孔壁的结合力弱,故可靠性不高. 多年来,美国GIL科技公司一直在研制替代聚四氟乙烯的材料,经过姐妹公司的合作,终于研制成功了TPA板材,这种材料克服了上述缺点,从而获得了美国专利.本文介绍了TPA层压板的电气特性、机械特性和热效应,给出了许多宝贵数据. 相似文献
99.
100.
Many companies are using Just-In-Time (JIT) control systems in their mixed-model multi-level production facilities. When scheduling these facilities the most important objective is to keep a constant rate of usage for every part used by the system. In this paper a mathematical model for scheduling these facilities is studied and techniques for determining good schedules are developed. Procedures for solving very large problems are given. 相似文献