USB设计常见错误分析

USB已经问世11年了，但人们每天都还是不断发现创新的方法来利用这套通讯协议；与此同时，他们也在成千种的设计方案中重复着相同的错误。USB和其他协议有着众多相似之处，这比工程师在PS／2与RS-232领域时一再犯下相同错误的程度还要不可思议。此外，面对严格的标准规范，工程师所犯的错误可能会造成不符USB规范的代价。     

The parabrachial nucleus is essential for acquisition of a conditioned odor aversion in rats.

Rats with bilateral ibotenic acid lesions of the gustatory zone of the parabrachial nuclei (PBN) failed to acquire a conditioned taste aversion (CTA) in Exp 1. They also failed to acquire a conditioned odor aversion (COA) when the olfactory cue was presented on an odor disk in Exp 2 or when it was presented in water in Exp 3. The failure to acquire the COA was not due to an inability to detect or use olfactory stimuli because the lesioned rats displayed neophobia to a novel odor in Exp 3 and used an olfactory cue to predict the availability of an aversive capsaicin solution in Exp 4. Together, the results demonstrate that, as with CTA learning, PBN cell bodies are essential for the establishment of a specific association between an olfactory conditioned stimulus and a lithium chloride unconditioned stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two-year behavior outcomes of project towards no tobacco use.

Presents a 2-year follow-up data from a school-based tobacco use prevention project designed to test the effectiveness of 3 primary components in social influence programs. The components either teach refusal skills, awareness of social value misperceptions, or physical consequences. Curricula were tested with a randomized experiment involving 48 junior high schools. Data suggested that a physical-consequences curriculum is successful at attenuating increases in adolescent smokeless tobacco use, cigarette experimentation may be attenuated by various approaches, and a comprehensive program with all 3 components was necessary to attenuate increases in weekly use of both forms of tobacco. These results also indicate that school-based tobacco use interventions can be effective at least 2 years postprogram, after students make their transition to high school. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Special stainless steels for the process industry

The requirements for and properties of steels to resist corrosion in many industrial applications are discussed. The economic aspects are also briefly considered.     

A simpler method for calculating the cost of conservation subsidies for an electric utility

This article presents a highly aggregated method of calculating the cost of conservation subsidies for an electric utility company. The cost is expressed in terms of the company's total expenditures on subsidies versus the reduction in electricity demand due to customers' extra conservation investments. We argue that the highly aggregated method would serve as a useful complement to the detailed programme by programme calculations normally performed to determine conservation cost-effectiveness. The simpler method is demonstrated with an application to the conservation programmes of the Pacific Gas and Electric Company.     

Double dissociation of effects on learning of medial versus lateral hyperstriatal lesions in pigeons.

Three experiments examined the effects of medial and lateral hyperstriatal lesions in two groups of pigeons. In Experiment 1, both hyperstriatal groups were impaired, relative to unoperated and operated control groups, in postoperative performance of preoperatively acquired serial reversal of both spatial and visual discriminations. The deficits of the two hyperstriatal groups appeared both quantitatively and qualitatively similar. Experiment 2 found that performance of spatial reversals was disrupted in the medial, but not in the lateral, hyperstriatal group by a long intertrial interval. Experiment 3 found that acquisition of simultaneous matching-to-sample was disrupted by lateral, but not by medial, hyperstriatal lesions; the lateral group also showed a lower rate of response to the sample stimulus than any of the other groups. Implications of these findings for current theories of hyperstriatal function are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Financial Viability of Fiber-Reinforced Polymer (FRP) Bridges

The application of fiber-reinforced polymer (FRP) technology to bridges can provide performance enhancements at a time when there is a large and growing need to replace aging bridges in the United States. However, construction costs are significantly higher than with traditional methods, and it is not clear if this technology can become competitive in the standard short-span bridge market. This study investigates current and future costs to determine how cost competitive this technology is likely to become, taking into account the expected improvements in manufacturing, transport, and installation, as well as life-cycle differences. Based on two demonstration FRP bridges and the learning curve approach, the results show that anticipated improvements would not be sufficient to compete on cost with reinforced-concrete bridges. Unless significant improvement also occurs in the cost of component material, this technology will not be cost competitive for the standard short-span bridge, and the application of FRP technology will be limited to other segments of the market, such as bridge deck construction and bridge repair.     

Primary grade teachers' instructional adaptations for struggling writers: A national survey.

Primary grade teachers from across the United States were surveyed about their instructional adaptations for weaker writers. Although many teachers were sensitive to struggling writers' individual needs, there was a sizable percentage of teachers (42%) who made few or no adaptations. The most common adaptations made by teachers addressed students' difficulties with the mechanics of writing or writing processes, such as planning and revising. Other adaptations that were relatively common involved providing extra conferences, minilessons, and reteaching. Percentage of classroom students with special needs and amount of time students spend writing each week both made a significant contribution to predicting the number of adaptations reported by teachers, once the contribution of all other variables was controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive Change 5 Years After Coronary Artery Bypass Surgery.

A longitudinal study of cognitive function after coronary artery bypass surgery examined 107 participants using 11 tests, preoperatively and at 6 days, 8 weeks, and 5 years after surgery. The overall neuropsychological (NP) change score declined at 6 days, showed some recovery at 8 weeks, and declined again at 5 years. The number of microemboli recorded during surgery, postoperative short-term cognitive change, and degree of recovery at 8 weeks were identified as predictors of change in NP score to 5 years. This suggests that even over a 5-year period, operative damage is detectable. Patients' vulnerability to short-term deterioration and resilience or ability to recover over a few weeks from operative cerebral insult are important processes of unknown mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)