第二代PPS

专门为3G增值关键的微型和超微型基站优化的模块化、低成本、可扩展和灵活性的预处理交换芯片. 第二代PPS支持3G部署策略的主要元素--模块化、性能、成本、可扩展性、灵活性和可重用性.因此,它有助于更加经济有效的和差异化的设计,并缩短上市时间.     

轻而易举通过HDMI符合性测试

引言 高分辨率多媒体接口（HDMI）正迅速成为在家庭娱乐系统中进行数字音频和视频数据传输的标准。该标准包括一个被称为显示数据信道（DDC）的l。C型总线，用于把扩展的数字接口数据（EDID）从受电设备（例如数字电视机）传送至源设备（比如数字AN接收机）。EDID包含有关受电设备能够接受的数字数据格式的重要信息。HDMI规范要求设备在其DDC总线线路上的输入电容低于50pF，满足此项要求会是一件非常困难的事，但是，LTC 4300A的电容缓冲功能使得设备能够轻松通过HDMI DDC输入电容符合性测试。     

An Enterprise-Wide Knowledge Management Approach to Project Management

Abstract

Few research studies investigate the relationship between enterprise knowledge management (KM) and project management (PM). These studies have shown that today’s PM approaches do not sufficiently include the required KM processes to derive the highest value from project investment. This research highlights the potential benefits of implementing an enterprise-wide KM approach to project management. The relationship between the four KM pillars, as defined by Stankosky, and the PM knowledge areas, as defined by the Project Management Institute (PMI), are investigated. A survey questionnaire reveals significant positive relationships between the KM pillars and PM knowledge areas. The significance and the nature of this association support the study’s assertion that the management of projects improves as enterprise-wide KM processes and activities are increasingly used.     

A basic need for integration – bringing focus to the scoping process

In response to the lead article in this edition, we have the following observations made mostly on our professional practice. First, good scoping is essential for effective impact assessment (IA) but is rarely done well. Second, interdisciplinary teams are also essential for effective IA and are often used. Third, the use of sustainability as a tool for doing IA is intellectually attractive but may conflict with IA legislation and so should be used only with care.     

Management of Crude Preheat Trains Subject to Fouling

Crude oil refinery preheat trains are designed to reduce energy consumption, but their operation can be hampered by fouling. Fouling behaviors vary from one refinery to the next. Effective management of preheat train operation requires inspection of historical plant performance data to determine fouling behaviors, and the exploitation of that knowledge in turn to predict future performance. Scenarios of interest can include performance based on current operating conditions, modifications such as heat exchanger retrofits, flow split control, and scheduling of cleaning actions. Historical plant monitoring data are frequently inconsistent and usually need to be subject to data reconciliation. Inadequate data reconciliation results in misleading information on fouling behavior. This article describes an approach to crude preheat train management from data reconciliation to analysis and scenario planning based around a preheat train simulator, smartPM, developed at Cambridge and IHS. The proposed methodology is illustrated through a case study that could be used as a management guideline for preheat train operations.     

Simultaneous determination of salsolinol enantiomers and dopamine in human plasma and cerebrospinal fluid by chemical derivatization coupled to chiral liquid chromatography/electrospray ionization-tandem mass spectrometry

A sensitive, specific, and robust method to simultaneously determine enantiomeric salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, SAL), a potential biomarker implicated in alcohol-related neurotoxicity in a stereoselective manner, and its precursor dopamine (DA) has been developed using simple chemical derivatization and chiral separation coupled with electrospray ionization-tandem mass spectrometry (ESI-MS/MS). SAL enantiomers and DA were converted to stable pentafluorobenzyl (PFB) derivatives directly from aqueous media. Bulky PFB groups introduced into the SAL structure enabled baseline separation of SAL stereoisomers on a chiral column without cumbersome chiral derivatization to unstable SAL diastereomers. Subsequent analysis by ESI-MS/MS with multiple reaction monitoring (MRM) in the presence of deuterium-labeled internal standards allowed specific detection of both derivatives with a wide dynamic range (SAL, 0.5-5000 pg; DA, 0.02-20 ng). The limit of quantitation assayed in the plasma matrix was below 10 pg for each SAL enantiomer and 100 pg for DA. Both coefficient of variance and error for inter- and intraday measurements in the blank plasma were less than 10% for SAL and DA in the concentration range of 10-4000 pg/mL and 0.1-8 ng/mL, respectively. This strategy enabled routine and specific determination of both SAL enantiomers and DA from 0.5 mL of human plasma and cerebrospinal fluid, which has not been possible using existing methodologies.     

Mainstream smoke emissions of Australian and Canadian cigarettes.

We investigated how mainstream smoke emissions vary and interrelate in 15 Australian and 21 Canadian brands, using public emissions disclosures from 2001. These disclosures provided emission data for 40 hazardous agents under both standard and intensive ISO testing conditions. Our analyses focused on "adjusted emissions" (i.e., emissions per milligram of nicotine yield) for 13 selected agents. Adjusted emissions differed significantly by ISO testing condition for 9 of the 13 selected agents. Intensive condition adjusted emissions were strongly negatively correlated for several agent pairs. Country and manufacturer variables were the strongest predictors of intensive condition adjusted emissions for 8 of the 13 selected agents and significant predictors for all of them. Taken together, these results suggest potential for the intent of emission limits to be undermined by risk swapping (in which one specific exposure is reduced within a group at the cost of another's exposure increasing) and risk shifting (in which a specific exposure is reduced within a group at the cost of that exposure's increasing within another group).     

Biomimetic formation of titania thin films: effect of amino acids on the deposition process

Different types of amino acids have been used as additives to control the aqueous deposition of titanium dioxide thin films on single-crystal Si wafers. Thin titania films can be obtained through a chemical bath deposition (CBD) process using TiCl? as a precursor in an aqueous solution at temperatures below 100 °C. The addition of amino acids to the deposition solution was shown to reduce the thickness and roughness of the films and to increase their density. These protein building blocks were employed to modify the deposition rate as well as the size of aggregates that form the film. The thickness, crystallinity, morphology and composition of the grown films were characterized by a variety of techniques, including XRD, XPS, AFM and SEM. The consequences of the type of the amino acid additive (and its concentration in the solution) on the microstructural evolutions of the deposed films are thus revealed and discussed on the basis of the organic-inorganic interactions in solution and at the film surface.     

利用红外成像技术的自动树冠温度估计

使用红外热像仪获取待测树冠图像,将树冠的光学图像与之配准.可采用彩色识别技术得到树叶的温度分布.这种处理的成功依赖于红外与光学图像配准,以及树叶区域精确提取的假设.实际上,简单的颜色识别算法无法正常工作.为此,提出了一种新方法来解决温度的估计问题.潜在的树叶温度分布可以认为是两个可分离的温度密度的融合.结合颜色识别与高...     

Unexpected new phase detected in FT30 type reverse osmosis membranes using scanning transmission X-ray microscopy

FT30 type thin film composite membranes used for reverse osmosis water purification are very difficult to analyze. With the remarkably thin polyamide layer and surface modification of the polymers now being reported, a new analytical technique is needed to determine the surface structure and chemical distribution in the active layer. In this study we show that scanning transmission X-ray microscopy (STXM) can be used to determine the spatial distribution of polyamide and polysulfone and we report on the detection of an unexpected new phase. The new phase was identified as a homopolymer of the meta-phenylene diamine (MPD) that forms in MPD solutions and can be incorporated into the discrimination layer during the interfacial reaction with the TMC to produce a mixed polyamide polyMPD layer. The detection of this second phase was only made possible by STXM. At the levels detected in membranes in this study (less than 8%) the second phase had no effect on the flux or salt passage of the membranes, however at higher levels a change in the membrane properties most likely would occur and the quantity of the polyMPD present should be eliminated or controlled.