接地线对微机继电保护设备的抗扰度影响试验分析

为了提高电子设备电路系统工作的稳定性，同时泄放由静电感应在机箱上积累的电荷，避免电荷积累形成的高压导致设备内部放电而造成干扰，为设备和操作人员提供安全保障，接地是一项极其必要的措施。但在干扰情况下，接地线的接地效果及其对设备的影响到底怎样，还并未做过详细试验。针对与此，对微机继电保护设备采用不同接地线时所能承受的干扰电压进行试验，并总结分析，提出设计及工程人员实际工作中应注意的问题。     

Ground truthing sediment profile imagery with traditional benthic survey data along an established disturbance gradient

Macrobenthic surveys are an expensive, slow and labour intensive means to establish the health of benthic communities. Sediment profile imagery (SPI) is a means of rapid reconnaissance for monitoring large areas of the benthos. SPI has often been used to monitor gross anthropogenic disturbance. The aim of this study is to determine if SPI can be used as a tool to reliably map change in communities along natural estuarine gradients. Macrobenthic sampling was carried out at five stations along an established estuarine gradient. This faunal data was analysed using standard multivariate techniques and to ground truth a concurrent SPI survey. Faunal analysis showed that habitat quality in Inner Galway Bay was generally good, with some localised disturbance from the River Corrib and the sewage out flow exterior to the city dock. Four distinct groups were identified with a degree of overlap occurring between stations 3 and 4. While existing SPI indices mapped habitat quality in the same manner as the faunal data for end member stations, the level of distinction between the habitats of an intermediate staging was found to be poor. This lack of distinction amongst the stage 2 and 3 stations was overcome by developing a tailored index, the Galway Bay index of habitat quality (GBHQ). This index was derived from the 5 observed variables in the SPI data that were determined to best match the faunal distribution by permutative mantel testing. The 5 observed variables from the SPI data were the depth of the apparent redox potential discontinuity (aRPD), the depth of penetration by the prism, and the presence/absence of infauna, surface faecal pellet layer and biogenic mounding. The GBHQ was able to distinguish between the 5 stations to a greater extent than previously described indices, showing clearly the separate groupings defined by the faunal data. The index was tested on a follow up SPI survey and shown to be applicable in mapping a broader range of habitats in Galway Bay. Indices generated for localised mapping of estuarine gradients should be derived from observed features and be ground truthed using faunal data. Some aspects of the GBHQ should be generally applicable to fine grained boreal estuarine sediments (aRPD/penetration), while others may be of limited utility in other locations depending on the digging characteristics of the particular SPI camera, and local factors influencing the persistence of biogenic features in the profile. This derivation technique provides a simple way to optimise SPI to particular studies and localities.     

Hybrid Electric Drive for DDG-51 Class Destroyers

The first of the Arleigh Burke class destroyers is nearing its mid-life. This class of ships was designed during the late 1970s through the 1980s to meet the threats that were prevalent at that time. Since entering service in 1991, these ships have shown themselves to be extremely versatile and the class now consists of nearly 60 ships in service. Their combat systems have been continually upgraded and adapted to meet the new threats the United States faces today. However, in order to keep these platforms viable throughout the first half of the 21st century, their operating costs must be reduced. Manpower, maintenance, and fuel are three of the top operating cost drivers. Most surface combatants spend very little of their underway time operating at full speed or even close to that. Over 1/3 of their underway time is spent at 12 knots and under. This is less than half of their maximum speed and only a fraction of the maximum power owing to the cubic speed–power relationship. Although the existing mechanical drive system is reasonably efficient, the main gas turbines are extremely inefficient at these very low power levels. A shaft-mounted auxiliary electric propulsion system (EPS) can take advantage of excess capacity in the ship service generators to reduce the main engine operating hours. Enabling bi-directional power flow from this auxiliary electric drive will provide additional generation capacity for ship service loads at a modest additional cost. It also provides a "cross-connect" capability from one shaft to the other. This paper will explore one prospect for reducing the operating cost of the DDG-51 class of ships by installing an auxiliary EPS that would powered by the ship service electrical plant. This additional system would serve to reduce both underway fuel usage as well as maintenance on the gas turbine main engines by reducing the number of operating hours on each engine. We will examine the technology trade-offs in this ongoing study.     

多核处理器基本原理及其在汽车领域中应用的展望

一个芯片上封装多个核心的新的处理器设计方式，成为了处理器微体系结构设计的趋势所在。介绍了多核处理器的发展过程和主要产品，简析了各种常见的多核处理器体系结构，讨论了各种多核处理器中的技术以及其相关系统及应用。     

Environmental trends of ports and harbours: Implications for planning and management

The traditional view of ports as evolving from human settlements to distribution centres is re-examined in an ecological context. The discussion is essential because of the persisting traditional approach to 'global' port development, i.e. directed primarily by technological optimization related to cargo transfer and ocean trasportation. Growing environmental concerns and realities indicate the need for a broader environmental view in which the port is recognized as part of a larger interactive coastal ecosystem, with environmental pressures by the port on the surrounding environment, as well as by the environment on the port. The paper argues for an ecological basis for coastal port development, analyses the environment implications of riverine linkages between port and hinterland, and details some environmental consequnces of changing industrialization and chemical practices. It also identifies initiatives for relevant planning and future port management.     

GLUTAMATE－IMMUNOREACTIVE NEURONS IN MEDULLARY RAPHE－CEREBELLUM PATHWAY IN THE KITTEN

ＧＬＵＴＡＭＡＴＥ－ＩＭＭＵＮＯＲＥＡＣＴＩＶＥＮＥＵＲＯＮＳＩＮＭＥＤＵＬＬＡＲＹＲＡＰＨＥ－ＣＥＲＥＢＥＬＬＵＭＰＡＴＨＷＡＹＩＮＴＨＥＫＩＴＴＥＮ（江赛男），（刘荣桓）ＪｉａｎｇＳａｉｎａｎ；,ＳｉｍｏｎＪ．Ｆｕｎｇ；ＬｉｕＲｏｎｇｈｕａｎ；，...     

新型快餐盒模拟铁路现场野外曝露试验

对三种材质、六种工艺、两种降解类型快餐盒的模拟铁路现场野外曝露试验表明，按１９９５年工艺生产的光一生物降解聚丙烯餐盒，在野外阳光等因素作用下，能较快地碎化、粉化，易为野外环境自然消纳，减容效果明显；纸制餐盒的生物降解性明显，回收价值高。该两类快餐盒较适合铁路目前使用。     

Systematic variability in repetitious travel

The focus of this paper is the degree to which day-to-day variability in the individual's travel pattern has a systematic, or nonrandom, component. We first review the different sources of variability in travel, emphasizing the difference between between-individual and within-individual variation and the implications of this difference for travel analysis. After discussing the impact of measurement (i.e. the way in which travel behavior is measured) on the study of repetition and variability, we use the Uppsala data to examine the level of systematic variability in an individual's longitudinal travel record. The analysis focuses on two questions:

- How well does observation over one week capture longer-term (five-week) travel behavior; in other words, is behavior highly repetitive from week to week?

- How systematic is within-individual variability; in other words, are certain stops distributed over the five-week record in a nonrandom, that is either regular or clustered, fashion?

Using measures of travel that include more than one stop attribute (e.g. activity, mode, time of day, and location), we found that:

- A seven-day record of travel does not capture most of the separate behaviors exhibited by the individual over a five-week period, but it does capture, for most people, a good sampling of the person's different typical daily travel patterns.

- Whereas a considerable portion of intraindividual variability is systematic (nonrandom), clustering is a more important source of nonrandom variation than is regularity.

The results suggest that behavior does not follow a weekly cycle closely enough for a one-week travel record to measure the longer-term frequency with which the individual makes certain stops or to assess the level of day-to-day variation present in the individual's record. Because these results are likely to reflect the particular measures of behavior we used, one conclusion of this study is the need for other studies that replicate the aims of this one but use a variety of other travel measures. Only through such additional work can we truly assess the sensitivity of our findings to measurement techniques.