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1.
Modeling of D-STATCOM in distribution systems load flow   总被引:1,自引:0,他引:1  
This paper presents modeling of Distribution STATCOM (D-STATCOM) in load flow calculations for the steady- state voltage compensation. An accurate model for D-STATCOM is derived to use in load flow calculations. The rating of this device as well as the direction of required reactive power injection for voltage compensation in the desired value (1 p.u.) is de- rived and discussed analytically and mathematically by the phasor diagram method. Furthermore, an efficient method for node and line identification used in load flow calculations is presented. The validity of the proposed model is examined by using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of D-STATCOM for under voltage problem mitigation approach in the distribution networks is determined. The results validate the proposed model for D- STATCOM in large distribution systems.  相似文献   
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We describe the development of a telephone-based program, Recreation, Education, and Socialization for Older Learning Veterans (RESOLV) that aims to connect Veterans with one another by phone and thereby reduce loneliness. The program was developed through a collaboration between VA and a community-based organization, Episcopal Senior Communities Senior Center Without Walls (SCWW). Semi-structured interviews were conducted with 18 rural and non-rural dwelling older Veterans to identify leisure interests and potential barriers to participating in leisure activities. Program feasibility was examined with questions about telephone use and interest in and perceived benefits of a telephone community. We conducted content analysis to quantify Veterans’ leisure interests and thematic analysis to characterize barriers to participation. Veterans expressed interest most frequently in groups focused on conversation, support, gratitude, and technology. Rural and non-rural participants did not differ significantly in interests. Barriers to current activity participation included limited access to activities, limitations due to physical conditions, and transportation difficulties, which were consistent themes for both rural and non-rural participants. Themes related to perceived benefits of socialization that emerged include connectedness, learning from others, being active despite limitations, and distraction from limitations. Our findings demonstrate how a telephone-based socialization program could be developed and tailored for older Veterans. It seems that such a program is feasible and may be of benefit for older Veterans in rural and non-rural areas. Further evaluation is needed to ascertain the direct benefit of such a program to older Veterans.  相似文献   
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In the present paper, a new Legendre wavelet operational matrix of derivative is presented. Shifted Legendre polynomials and their properties are employed for deriving a general procedure for forming this matrix. The application of the proposed operational matrix for solving initial and boundary value problems is explained. Then the scheme is tested for linear and nonlinear singular examples. The obtained results demonstrate efficiency and capability of the proposed method.  相似文献   
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Objective  

The roles of gonadal hormones and nitric oxide (NO) on the analgesic effects of morphine, tolerance to morphine, and their interactions have been widely investigated. In the present study, the effect of l-arginine (an NO precursor) on morphine tolerance in sham and ovariectomized (OVX) female mice was investigated.  相似文献   
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We examined written expression performance in a sample of adolescents with ADHD and subthreshold ADHD using two different strategies: examining performance on standardized measures of written expression and using other indicators of written expression developed in this study. We examined associations between standardized measures of written expression, cognitive processing measures (working memory, processing speed, language, fine motor ability, and reading efficiency) and behavioral ratings of ADHD by parents and teachers. We also developed a coding scheme for a writing sample to measure productivity and the ratio of self-corrections to errors. The results indicated that written expression performance was most consistently associated with cognitive processing measures and not behavioral ratings of ADHD, based on correlational and simultaneous regression analyses. These results were consistent in the analyses with both the standardized measures and the coding scheme measures of written expression. Findings generally remained robust, regardless of whether participants who met criteria for a learning disability were included or excluded in the analyses. The current results suggest that written expression difficulties in adolescents with ADHD are attributable to processing difficulties that may be associated with ADHD, not to ADHD reported symptoms. Implications for assessment and intervention are discussed.  相似文献   
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蛋白质糖基化修饰研究进展   总被引:2,自引:0,他引:2  
李军  杜鑫  陈玉银 《科技通报》2009,25(6):773-778,783
蛋白质翻译后修饰是蛋白质组学的一个组成部分,而蛋白质糖基化是生命体中最重要的一种蛋白质翻译后修饰之一。糖基化在细胞免疫、信号传导、蛋白翻译调控、蛋白降解等诸多生物过程中起着重要作用。随着蛋白质组学技术的不断发展,糖基化研究也越来越受到广泛的关注。本文综述了糖基化的分类、在生命体中的作用、最新的研究技术及进展。  相似文献   
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We present a method to perform sample concentration within a lab-on-a-chip using a microfluidic structure which controls the liquid-gas interface through a micropillar array fabricated in polydimethylsiloxane between microfluidic channels. The microstructure confines the liquid flow and a thermal gradient is used to drive evaporation at the liquid-gas-interface. The evaporation occurs in-plane to the microfluidic device, allowing for precise control of the ambient environment. This method is demonstrated with a sample containing 1 μm, 100 nm fluorescent beads and SYTO-9 labelled Escherichia coli bacteria. Over 100 s, the fluorescent beads and bacteria are concentrated by a factor of 10.  相似文献   
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Participant observation was conducted for 1 year with six mildly learning handicapped young adults following their graduation from high school. Close attention was paid to the ways in which they managed the transition out of school and into more adult roles. During this year, all six floundered from job to job, class to class, and school to school. They expressed discontent and frustration with their present situation. They were at a loss to plan for the future and maintained an unrealistic appraisal of their skills. Their sense of self waxed and waned in keeping with their prospects, and the patience and frustration of family members vacillated as well.  相似文献   
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