LNG冷量优化集成利用技术

我国将相继在沿海地区建成多个LNG接收站，每年将进口数以千万吨计的LNG，同时携带数着巨额冷量，而这些冷量可用于发电、空气分离、制造干冰、低温冷库等众多领域。基于国外LNG冷量利用现状，指出我国即将展开和实施此项技术还存在着：过程火用损较大，缺乏系统、全面的LNG冷量利用技术的研发指导机制，以及宏观调控力度薄弱等问题，进而提出了发展LNG冷量的集成利用方案，可为此类技术的研发利用提供新思路。以福建即将进口的LNG为例，模拟了空气分离与干冰制备的集成工艺流程，结果表明：福建每年进口的260×10⁴t LNG可以冷却290×10⁴t空气，相当于60000 m³/h的氧气制备规模，还可以生产100×10⁴t的干冰，其过程火用损较小；其剩余的高温位冷量可应用于低温冻结库或冰灯等项目，这对主体装置的实施效果和过程火用损的影响较小。该技术的优点在于可灵活控制冷却空气的液化率，基本不用冷却循环水，流程简单，设备投资少，能耗低等。     

238C防盗报警系统的改进

漯河中波台自安装238C防盗报警系统以来,多次出现误报现象,严重影响了发射及其他工作的正常进行。首先对该系统的工作原理进行了简单介绍,然后对误报故障现象进行了分析、处理,并改进了电路设计中存在的不足。改进后的运行数据表明,系统误报率明显下降,达到了预期的目的。最后,对本系统的设计提出了进一步完善的建议。     

A Bluetooth Based Sensor Network for Civil Infrastructure Health Monitoring

Communicating with sensors has long been limited either to wired connections or to proprietary wireless communication protocols. Using a ubiquitous and inexpensive wireless communication technology to create Sensor Area Networks (SANs) will accelerate the extensive deployment of sensor technology. Bluetooth, an emerging, worldwide standard for inexpensive, local wireless communication is a viable choice for SANs because of its inherent support for some of the important requirements – low power, small form factor, low cost and sufficient communication range. In this paper we outline an approach, centered on the Bluetooth technology, to support a sensor network composed of fixed wireless sensors for health monitoring of highways, bridges and other civil infrastructures. We present a topology formation scheme that not only takes into account the traffic generated by different sensors but also the associated link strengths, buffer capacities and energy availability. The algorithm makes no particular assumptions as to the placement of nodes, and not all nodes need to be in radio proximity of each other. The output is a tree shaped scatternet rooted at the sensor hub (data logger) that is balanced in terms of traffic carried on each of the links. We also analyze the scheduling, routing and healing aspects of the resulting sensor-net topology.     

Measuring College Students' Motives for Playing Drinking Games.

Students may choose to play drinking games not only for reasons related to alcohol consumption but also because of incentives related to other aspects of play (competition, fun, interpersonal dominance, etc.). College students (120 men and 167 women) completed measures of motives for playing (based on T. J. Johnson, S. Hamilton, & V. L. Sheets, 1999) and consequences of playing drinking games. Exploratory principal-components analysis identified 8 reasons for playing. Men and women differed in their endorsement of the factors. Motives for play directly predicted consequences of play independently of alcohol consumption. Specific motives predicted specific types of consequences. In multiple regression analyses, Conformity motives were negatively related to consequences and may represent a form of protective motive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

抽油机井系统效率简析

油田生产中广泛使用抽油机采油,机械采油的系统效率主要有地面效率与井下效率。在实际生产中,地面效率容易检测、计算和调整,井下效率则取决于产液量、动液面、泵效以及管柱的状况。文章仅对抽油机井系统效率进行简单分析与计算,旨在为优化设计抽油机运行参数提供参考。     

Nonlinear Propagation of Coupling Optical Pulse under Compton Scattering in Laser Medium

After considering Kerr nonlinear effect,group velocity dispersion of host and gain distribution of active particle in laser amplifying medium,a basic equation describing propagation of the coupling optical pulse under the multi-photon nonlinear Compton scattering in the laser amplifying medium has been deduced. Besides,the profile and power spectrum of a picosecond-level super-Gaussian coupling pulse in the laser amplifying medium have been discussed when its central frequency coincides with the gain peak frequency of the laser amplifying medium.     

Scheduling Algorithms for Packet-Oriented MAC Protocols in Wireless Multimedia Systems

Future generation wireless multimediacommunications will require efficient Medium AccessControl (MAC) protocols able to guarantee suitable Qualityof Service (QoS) levels for different traffic classes whileachieving a high utilization of radio resources. This paperproposes a new scheduling technique to be adopted at the MAClevel in wireless access systems, named Dynamic Scheduling-Time DivisionDuplexing (DS-TDD), that efficiently managesvideo, voice, Web and background traffics. A theoretical approachis proposed in this paper to evaluate the DS-TDD performance withvoice and Web traffics. Simulation results have permitted tohighlight the following promising characteristics of the DS-TDDscheme: (i) a high capacity of real-time traffics isattained with a QoS insensitive to Web and background trafficloads; (ii) a high throughput can be guaranteed whilepreserving the QoS levels of the different traffic classes;(iii) heavier downlink traffic loads do not modify the QoSof uplink traffics. Finally, extensive comparisons with differentscheduling schemes proposed in the literature have permitted tohighlight the better performanceof DS-TDD.     

企业中层管理人员培训的思考

以分析企业中层管理人员培训的现状为突破口,阐述了中层管理人员培训需求分析的思路和方法。在此基础上对培训内容进行整体设计,指出针对此类培训应采用的培训方式和评估方法。以期对企业中层管理人员的培训起到一些启发和借鉴作用。     

单光纤传输光推动便携式压力测量仪的研究

介绍了用单根光纤传输测量信号和功率信号的光功率推动液体压力测量仪及其工作原理。该仪器以电容式压力传感器的δ元件作为压力检测元件，采用低功耗前置器电路和简单直杆结构，实现了便携式测量。测量范围为O～100kPa，精度为O．01kPa。     

金属换热器选用经济分析

本文以系统节能和提高综合经济效益的观点，分析了金属换热器传热系数的影响因素及提高途径；气流阻力与动力消耗；传热面积与投资的定量关系。为正确选用不同结构金属换热器及其性能提供了依据。