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排序方式: 共有365条查询结果,搜索用时 31 毫秒
31.
A partnership has been developed linking the United States Military Academy and Special People in the Northeast, a non-profit agency for the mentally and physically handicapped children and adults based in Philadelphia. The present work documents a student design team's design and construction of a ticket-tearing device for a young man in the advanced stages of cerebral palsy and concludes with an evaluation of the entire process. 相似文献
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Alok Warey Sandro Balestrino Pat Szymkowicz M. R. Malayeri 《Aerosol science and technology》2013,47(2):198-213
Cooled exhaust gas recirculation (EGR) is widely used in diesel engines to control engine out NOx (oxides of nitrogen) emissions. A portion of the exhaust gases is recirculated into the intake manifold of the engine after cooling it through a heat exchanger. EGR cooler heat exchangers, however, tend to lose efficiency and have increased pressure drop as deposit forms on the heat exchanger surface. This adversely affects the combustion process, engine durability, and emissions. In this study, a 1-D model was developed to simulate soot deposition, soot removal, and condensation of several hydrocarbon (HC) species in a circular tube with turbulent gas flow at constant wall temperature. The circular tube, which makes up the computational domain in the model, represents a single channel from any EGR cooler geometry. The model takes into account soot particle deposition due to thermophoresis, diffusion, turbulent impaction, and gravitational drift. However, thermophoresis was found to be the most dominant deposition mechanism for boundary conditions at which EGR coolers typically operate. Soot removal was modeled by considering a force balance between the drag and van der Waals forces. A lognormal distribution of particles was assumed at the tube inlet. The evolution of the particle distribution in the bulk flow along the tube as well as the mass distribution in the deposit layer on the tube walls is predicted by the model. Condensation of six HC species between C15-C24 alkanes was also modeled. Predictions made by the model are in reasonably good agreement with experimental data obtained from a laboratory reactor under the same boundary conditions. There are several assumptions and simplifications built into the model, which can be refined further to improve it. Copyright 2012 American Association for Aerosol Research 相似文献
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This article presents an overview of J. Bowlby's framework of attachment (e.g., 1990) for conceptualizing adult psychopathology and its application to clinical practice. The theory proposes that psychological disorders reflect an internalization of adverse attachment experiences, both current and past, and in particular those that undermine self-reliance and feelings of security. Clinical syndromes indicate intensification of anxiety, depression, and/or anger to a degree which interferes with adaptive functioning and interactions with others. The secure base of therapy provides a new model of what close relationships can be like, as well as a setting for exploring and possibly modifying the meaning given to separation and loss experiences. Issues of prevention and social policy are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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In an attempt to expand understanding of more severe pathology, attachment theory, developed by John Bowlby, is applied to borderline personality disorder in adults. Conceptualized as a condition of profound insecure attachment, with extreme vacillations between a desire for proximity and attachment and a dread and avoidance of engagement, borderline pathology reflects traumatic attachment experiences, beginning early in life. Besides the importance of trauma, disturbances in affect regulation and cognitive distortions are emphasized. The secure base of a therapeutic bond provides consistency, reliability, and affirmation while encouraging exploration of separation and loss experiences, both current and past, in order to modify inner working models of oneself and relationships with others. Implications for prevention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Gallagher-Thompson Dolores; Futterman Andrew; Hanley-Peterson Pat; Zeiss Antonette; Ironson Gail; Thompson Larry W. 《Canadian Metallurgical Quarterly》1992,60(2):300
Describes agreement among diagnoses made according to 5 definitions of endogenous depression in a sample of 99 depressed elders and discusses the relationship among these systems and selected demographic and clinical characteristics. Poor to fair agreement was generally demonstrated, except for Research Diagnostic Criteria (R. Spitzer et al, 1978) and Diagnostic and Statistical Manual of Mental Disorders-III—Revised (DSM-III—R), which demonstrated excellent agreement. Mostly, demographic and clinical variables (e.g., severity of depression) were unrelated to endogeneity diagnoses. The conclusion was reached that these criteria are not all measuring the same construct in older adults and that the relationship between depression severity and endogeneity should be discussed in terms of specific definitions rather than in general terms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Dinesh Chamund Bill Findlay Kevan Birkett Dynex Semiconductor Pat Wheeler Jon Clare Michael Bland 《电力电子》2005,3(3):40-44
双向IGBT模块是实现高频矩阵变换器极为有效的方法。略不同于硬开关PWM变换器,矩阵变换器中的开关和传导损耗取决于所选的调制策略。本文介绍了一种由诺丁汉大学推导的平均损耗的计算公式。测试一个使用1200V,200A的双向模块实现的三相到单相的构造,得到的波形说明了矩阵变换器的实际操作以及可能会出现的输出电流纹波。 相似文献
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