TPS6211x电源供应设计的实际考虑

作者:Jeff Falin、Bill Johns·电源管理产品/便携式电源DC/DC应用TPS6211x dc/dc转换器是一种同步降压转换器,其输入电压最高可达17V,输出电压范围为1.2-16V,输出电流高达1.5A。该器件可以高效地将两节锂离子电池、铅酸蓄电池或12V-15V系统电压降至5V、3.3V或者更低。图1为典型应用电路。图1:典型应用本文将提供TPS62111x降压转换器的示例应用并对关键特性进行总结,以供实际设计参考。外部组件的尺寸要求集成FET及内部补偿功能可进一步减少外部组件教。假设不使用集成输出电压与输入电压监控电路,则固定输出电压(5V或3.3V)时仅…     

蓝牙技术在医疗上的应用--可远程、安全、轻松地收集和存取病人数据

在个人数字助理(PDA)、笔记本电脑和蜂窝电话上使用蓝牙技术的产品,正在更加方便、可靠地通过远程、无线方式收集病人数据.这一现象使医疗设备制造商正在重新考虑通过蓝牙技术收集、处理和整理病人的数据.特别是,蓝牙技术的电缆替代能力、低功耗、高可移动性和近距离安全特性,使医疗设备制造商更希望使用这一技术.蓝牙技术最初只是一种电缆替代技术,现在它的发展已经远远超出了最初的设计,并仍在不断向前发展,成为一种能够为各种标准设备和Ad-Hoc(自组织网络)网络提供接入的技术.     

From application service provision to service-oriented computing: A study of the IT outsourcing evolution

IT outsourcing is not a new concept. Originating from the early 60’s in the form of time sharing, IT outsourcing has evolved to the application service provision (ASP) model, in the late 90’s to pure services in the beginning of the century. Services, and their major representative web services, are actually the next phase of the movement toward Internet-based componentized software, known in the not so distant past as ASP. As the continuous expansion of the Internet and its relating technologies creates new marketing opportunities, traditional monolithic architectures are giving way to service-oriented computing (SOC), the architecture that enables service provision. SOC permits the utilization of large systems which are comprised of self-containing building blocks: services. Services may be made public, searched, reused and combined to form complex business processes while in the same time retaining a significant level of flexibility. Services and SOC have emerged as a response to a fundamental shift in enterprise business culture that started at the late 90’s. Although they are promising as an IT outsourcing enabler, many issues need to be dealt with before they can be considered suitable for wide adoption. These issues are of technological, business, economic and cultural nature and they were also faced by ASPs in the past. It is worth revisiting the successes and failures of the ASP model in order to get a better understanding of the evolving IT outsourcing industry. In this work, we describe the evolution of service provision from its initial form as software application, through the application service provision era and towards the new trend of web services.     

Locus of control and "pseudovolunteering."

Possible bias in social science research is of increasing importance because of the use of volunteer Ss. The present results with 51 college students suggest that a volunteer population ( n = 39) may be an even more select group than previously thought, since they were different from those Ss ( n = 12) who initially volunteered but did not complete their participation in the research project (pseudovolunteers). With respect to Rotter's Internal-External Control Scale, pseudovolunteers were significantly more external in orientation than true volunteers. The implications of using volunteer populations, particularly in relation to the generalizability of results, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effect of Thyme Oil Low-Density Polyethylene Impregnated Pellets in Polylactic Acid Sachets on Storage Quality of Ready-to-Eat Avocado

After earlier promising results for the control of anthracnose in avocado fruit by thyme vapours, our studies were extended to commercial use in tray packs. The effect of thyme oil low-density polyethylene impregnated pellets (TO-LDPE-P) in polylactic acid (PLA) sachets was investigated for the control of anthracnose and retention of dietary phytochemicals, fatty acid composition, D-mannoheptulose sugar and fruit quality in ready-to-eat avocado fruit. The 10% TO-LDPE-P significantly reduced the incidence severity of anthracnose and enabled the retention of dietary phytochemicals (p-coumaric, ferulic and caffeic acid, catechin and epicatechin), fatty acids, mannoheptulose, fruit firmness and taste compared to the currently used prochloraz^® fungicide treatment. The results of this study strongly suggest the incorporation of 10% TO-LDPE-P in PLA sachets in commercial avocado tray packs as a natural option to improve fruit health, dietary phytochemicals, fatty acid composition and consumer satisfaction.     

Abiotic reductive dechlorination of chlorinated ethylenes by iron-bearing soil minerals. 1. Pyrite and magnetite

Abiotic reductive dechlorination of chlorinated ethylenes (tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), and vinyl chloride (VC)) by pyrite and magnetite was characterized in a batch reactor system. Dechlorination kinetics was adequately described by a modified Langmuir-Hinshelwood model that includes the effect of a decreasing reductive capacity of soil mineral. The kinetic rate constant for the reductive dechlorination of target organics at reactive sites of soil minerals was in the range of 0.185 (+/- 0.023) to 1.71 (+/- 0.06) day(-1). The calculated specific reductive capacity of soil minerals for target organics was in the range of 0.33 (+/- 0.02) to 2.26 (+/- 0.06) microM/g and sorption coefficient was in the range of 0.181 (+/- 0.006) to 0.7 (+/- 0.022) mM(-1). Surface area-normalized pseudo-first-order initial rate constants for target organics by pyrite were found to be 23.5 to 40.3 times greater than those by magnetite. Target organics were mainly transformed to acetylene and small amount of chlorinated intermediates, which suggests that beta-elimination was the main dechlorination pathway. The dechlorination of VC followed a hydrogenolysis pathway to produce ethylene and ethane. The addition of Fe(II) increased the dechlorination rate of cis-DCE and VC in magnetite suspension by nearly a factor of 10. The results obtained in this research provide basic knowledge to better predict the fate of chlorinated ethylenes and to understand the potential of abiotic processes in natural attenuation.     

全球废纸回收、利用情况及供求趋势

废纸应用的世界趋势 废纸在世界纸和纸板制造纤维配料中的比例已从1990年的35％增加到当前的46％（见图1）。尽管废纸应用比例的增长开始趋缓，但到2012年将达到50％。重要的是同时应注意到世界纸和纸板总需求在未来5年中的增长，因此，未来废纸需求的增长不仅仅因为废纸纤维配比的增加。     

Improvement and induction property of radiation-responsive promoter through DNA shuffling of 5′-flanking regions of the human p21 gene

A promoter that augments gene expression in response to stimulation of ionizing radiation would be a desired tool for radiogenetic therapy, a combination of radiotherapy and gene therapy. Although various promoters occurring naturally or artificially have been used for researches, one showing higher reactivity to ionizing radiation is desirable. In the present study, we attempted to improve a radiation-responsive promoter of the p21 through a technique called DNA shuffling. A library of DNA fragments was constructed by re-ligation of randomly digested promoter fragments and improved promoters were chosen out of the library. We repeated this process twice to obtain a promoter showing 2.6-fold better reactivity to ionizing radiation compared with its parent, p21 promoter after 10 Gy γ-ray irradiation. Nucleotide sequence analyses revealed that the obtained promoter was densely packed with some of the cis-acting elements including binding sites for p53, NF-κB, NRF-2, AP-1 and NF-Y more than p21 promoter. In addition, it was shown that its induction by ionizing radiation was dependent upon p53 status of a cell line, suggesting that the promoter retained properties of the p21 promoter. This technique is simple and efficient to improve a promoter responsive to other stimulus of interest besides IR.     

NEO河畔公寓

在这个严谨而杰出作品中,细部和建造技术格外受关注。建筑中每样东西都是美的创造。It＇s a tour de force of rigour,exceptional attention to detail,and engineering,Everything is beautifully made.这个住宅项目位于伦敦河畔地区的核心地带,它靠近泰晤士河,并与泰特现代艺术馆扩建部分的西门直接相对,NEO河畔公寓包括217个居住单元,分布于四栋建筑的12层至24层间。这四个六边形的大楼给居住者提供了舒适的居住条件、良好的景观视野和充足的阳光。这些钢和玻璃建造的塔楼,与周边环境形成了呼应。     

对于企业社会责任,ERP如何应对?(英文)

对于企业社会责任,ERP如何应对? 面对ISO 26000社会责任国际标准,以ERP为代表的企业软体如何应对人权、环境、公平等诉求的挑战?