Automatic dispensing of dichlorvos to control Ephestia kuehniella Zell. (Lepidoptera: Phycitidae) in flour mills

Dichlorvos applied weekly at the rate of 14.0 μg/l gave good control of Ephestia kuehniella in a flour mill. Other insects were also controlled. The insecticide was dispensed automatically by electrically operated sprayers when the mill was unoccupied. Exposure of test insects and chemical determinations of atmospheric concentrations showed that good distribution of vapour was obtained. Concentrations of dichlorvos were at a safe level for working well before the mill reopened after 8 hr. Contamination of flour was negligible. The method involves no disruption of routine working and there is no vapour hazard to workers.     

用于辅助驾驶系统的可编程平台

安全性是汽车消费者最关心的问题了。图1给出了Visteon进行的一项研究结果,图中显示出客户对汽车的要求,而车辆安全性位于核心。对于汽车安全性的关注不仅仅是为了司机和乘客,还有道路上的其他人。安全设备已经从物理领域转向电子领域,从轮胎和刹车技术的进步,到侧撞保护和安全     

Quality characteristics of fresh blue crab meat held at 0 and 4 degrees C in tamper-evident containers.

There has been a regulatory movement toward the required use of tamper-evident containers for fresh blue crab meat. North Carolina passed tamper-evident regulations in 1993. Blue crab processors had little information on possible changes in head-space gases, microbial growth, chemical decomposition, sensory quality, or shelf life caused by the new containers. Chemical, microbiological, physical, and sensory changes in fresh crab meat were monitored during 18 days of storage in ice and 13 days of storage refrigerated at 4 degrees C. "Special" blue crab meat, chosen for the study, is the least expensive commercial form of white crab meat. The crab meat was packaged in four retail containers: copolymer polyethylene cups with polyethylene snap-on lids, copolymer polyethylene cups with snap-on polyethylene lids fastened to the cup with heat-shrink low-density polypropylene seals, copolymer polyethylene cans with aluminum easy-open ends, and copolymer polypropylene cups with a tamper-evident pull-tab on the lid. Control samples packaged in industry standard copolymer polyethylene cups maintained higher oxygen levels than meat stored in tamper-evident containers. No consistent differences in quality or shelf life were detected among the containers. Market shelf life was limited to 6 days for meat held at 4 degrees C and 15 days for meat held at 0 degrees C. Sensory quality deteriorated 6 days earlier for crab meat held at 4 degrees C than meat held at 0 degrees C. Collateral work showed that toxin production by Clostridium botulinum neither occurred following 18 days of storage at 4 degrees C nor after 15 days of storage at 10 degrees C. Definite spoilage occurred before any toxin production. The study suggests that blue crab processors can safely use the new tamper-evident packaging, which has little or no effect on product quality or shelf life. Processors may choose appropriate packaging options using price, packaging quality, market appearance, and ease of production as the deciding criteria.     

A method for automatically finding multiple operating points in nonlinear circuits

A new algorithm based on a SPICE-like simulator that searches for multiple operating points automatically, with no user intervention required, is presented. This algorithm, which exploits the asymmetrical properties of nonlinear mappings that describe multistable circuits, has been implemented into a program which automatically finds multiple (in most cases, all) operating points of a circuit. In addition to finding multiple operating points, this method offers another feature: it is capable of detecting the stability of a particular operating point. Another useful feature of this method is that it allows the user to gauge how close a particular circuit is to possessing multiple operating points. For circuits known to possess multiple operating points, this method allows the user to specify which operating point is encountered first. Unlike other continuation methods, circuit element models are not modified; only augmenting resistors are required. Hence, this approach lends itself well as an "add-on" to existing circuit simulators. A number of circuit examples are given.     

纳米Al/Al2O3多层膜的光电子谱与电性能

用热蒸发和自然氧化法制备纳米量级Al/Al2O3多层膜.检测XPS光电子能谱和UPS谱线,得到Ei(k∥I)关系曲线,并发现薄膜具有负阻特性.     

Large area, concentrator buried contact solar cells

Considerable interest has been shown commercially in the buried contact solar cell (BCSC) approach, particularly for large area one-sun cells and large area concentrator cells. Efficiencies in the range of 21-22% have been independently confirmed by Sandia National Laboratories for a 20-cm² device operating at 20 suns using prismatic covers. An alternative, innovative approach for groove and metallization formation has enabled the demonstration of similar efficiencies but without the use of prismatic covers. These are believed to be the highest reported efficiencies by a clear margin for any concentrator cell of this size     

Assessing a multidimensional measure of radical technologicalinnovation

For almost 30 years, innovations have been characterized as radical or incremental. Nevertheless, the construct has not been precisely defined and ad hoc measures have been the norm in the literature. This paper describes the development of measures which address multiple dimensions of the concept of innovation radicalness and treat it as a continuous variable. A rigorous process of item development, reliability analysis, and both exploratory and confirmatory factor analysis was used. The developed measures meet psychometric standards, demonstrate criterion-related validity, and capture four dimensions of radicalness: technological uncertainty, technical inexperience, business inexperience, and technology cost. Findings support the conceptualization of radicalness as a continuum with multiple dimensions, and suggest that those dimensions may be differentially related to project characteristics and outcomes. The utility of these measures and dimensions as diagnostic tools in project management is discussed. Radicalness as a multidimensional concept is also discussed as a valuable tool in project planning, project evaluation, and understanding the strategic implications of pursuing radical innovation     

SHORT COMMUNICATION: Solar cell efficiency tables (version 25)

Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since June 2004 are reviewed. Copyright © 2005 John Wiley & Sons, Ltd.     

现代通信测试设备必须适合多种手机标准--谈如何选择射频功率分析测试仪器

在通信设备生产领域，射频功率的测量是必不可少的。主信道的功率测量往往决定了接通的质量，邻信道的功率测量则决定不同手机用户之间的干扰程度。而所有上述的指标必须符合相应的工业标准。例如，cdmaOne的手机标准清楚定义了频谱相对于载频的最大干扰度，并指明了有关射频功率测试的详细办法。单纯的功率表往往不能提供与频谱相关的测试功能，因为其不能分辨总功率下的不同子功率，也不能分辨被测发射带宽区域内外的频率。但是，单纯的功率表较为便宜，价格一般为5000美金左右，这对于那些在生产过程中只测量总输出功率的用户来说是符合…     

PMD and PDL monitoring of traffic-carrying transatlantic fibre-optic system

For the first time the direct monitoring of polarisation mode dispersion (PMD) and polarisation-dependent loss (PDL) in a traffic-carrying transatlantic fibre-optic system without the requirement of loopingback is reported. The impact of transmitter polarisation scrambling in the measured results is analysed and verified by the measured results.