Performance of compression/absorption hybrid refrigeration cycle with propane/mineral oil combination

This paper discusses the feasibility of a vapor compression/absorption hybrid refrigeration cycle for energy saving and utilization of waste heat. The cycle employs propane as a natural refrigerant and a refrigeration oil as an absorbent. A prototype of the cycle is constructed, in which a compressor and an absorption unit are combined in series. The performance of the cycle is examined both theoretically and experimentally. Although the solubility of the propane with the oil is not enough as a working pair in the absorption unit, the theoretical calculation shows that the hybrid cycle has a potential to achieve a higher performance in comparison with a simple vapor compression cycle by using the waste heat. In the experiment, the prototype cycle is operated successfully and it is found that an improvement of an absorber is necessary to achieve the good performance close to the theoretical one. The application of an AHE (absorber heat exchanger) can reduce the heat input to a generator. Further examinations on some other combinations of refrigerant/refrigeration oil and additives are desirable.     

转制科研单位建立和完善内部会计控制的探讨

针对目前大多数科研单位在内部会计控制中存在的问题,根据财政部颁布的《内部会计控制规范一基本规范》,探讨了科研单位在转制过程中应如何建立和完善内部会计控制制度,以达到防范经营风险,保护资产安全、完整,确保经营管理目标和政策有效实施.     

论城市轨道交通传输网络的设计方案

对城市轨道交通通信系统的传输网络需求进行了分析，对各种传输制式进行了比较，提出了城市轨道交通通信系统传输网络的最佳解决方案。     

Calorimetric determination of the enthalpy change for the binding of methyl orange to poly(vinylpyrrolidone) in aqueous solution

Thermodynamic parameters have been determined for the interaction of methyl orange and poly(vinylpyrrolidone) in aqueous solutions containing tris, tris and hydrochloric acid, or water only. Enthalpy changes were determined by use of a flow microcalorimeter. Free energy changes were calculated from the results of equilbrium dialysis studies. The results are interpreted in terms of the behaviour of poly(vinylpyrrolidone) in these systems. Analysis of data shows that the hydrophobic interactions in the systems are in the order: tris > wateronly > tris-HC1.     

Quantitative evaluation of generator power control effect of FACTS controllers for power system stabilization

The advancement of power electronics technologies has significantly developed the power system stabilizing controllers. Quantitative as well as qualitative evaluation of their effectiveness in power systems is a matter of great importance for the feasibility investigation of these apparatus. In this paper, the possible control region of FACTS controllers with series and/or shunt configuration in a single machine to infinite bus system is formulated in the powerangle curve with a set of algebraic equations. The effectiveness of TCPST (Thyristor‐Controlled Phase Shifting Transformer), SSSC (Static Synchronous Series Compensator), and TCSC (Thyristor‐Controlled Series Compensator) for the improvement of the transient stability is evaluated quantitatively as a numerical example. The correctness of the proposed method has been confirmed by analysis based on the electromagnetic transients simulation with a detailed system model. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 43–51, 2002     

基于CEBus的家庭网络通信系统设计研究

介绍一种参照CEBus标准中电力线载波规范设计实现的家庭网络通信系统。它主要由集中配置的中心主控设备(MCU)和分散配置的数字控制单元(DCU)构成,以家庭中的220V(或380V)电力线为传输媒介。MCU可以实现对DCU中连接家电产品的开关调控及状态信息的收集处理,同时MCU还作为网关设备提供在Internet、电话网络及无线遥控终端上对家电产品实现远程测控的接口。     

MIMO扩频通信系统矩阵信道估计

为了解决第三代移动通信系统下行链路容量瓶颈问题，在HSDPA的解决方案中，MIMO系统的提案越来越受到重视。本文提出了一种移动深衰落环境下的MIMO系统信道估计方案，并进行了详细的理论推导，给出了独立MIMO深衰落信道环境下的仿真结果。     

基于CPX8216硬件平台的GPRS板间切换的实现

GPRS全称通用分组无线业务,它在改进了现有GSM系统后能实现高速的数据传输。首先对GPRS系统做了简单介绍,然后在此基础上详细介绍了GPRS的板间切换在CPX8216硬件平台上的实现方法。     

重油催化裂化装置再生器的改造

上海石化股份公司重油催化裂化装置为反应沉降器与再生器并列布置 ,两个再生器同轴布置。通过处理能力由 0 .8Mt/a提高至 1.0Mt/a的局部改造后 ,该装置产生了外取热器无法正常投用 ,两个再生器烧焦比例不易合理分配、第一再生器 (一再 )烧焦强度较低、剂油比偏低及催化剂单耗偏高等问题。因此 ,又对再生器进行了改造 :将一再船形待生催化剂分布器改为Y形分布器、在一再密相床上部增设格栅、外取热器催化剂返回分布器增设软密封、待生催化剂输送线路由斜管 立管 斜管的形式改为斜管形式等 ,改造效果好。     

金刚石磨具新型制造方法的试验研究

金刚石磨具已广泛用于宝石加工业。对电镀法制造金刚石磨具进行了试验研究，该工艺可分为电镀前的预处理、金刚石磨具的电镀工艺，对影响镀层质量的因素进行了分析。