利用BSO晶体实现光强的非线性调制

利用BSO晶体的电光效应和光电导效应实现了光强的非线性调制,在0～25mW Ar~+激光入射情况下得到了类似于饱和吸收体的非线性透过率。     

Performance analysis of linear MIMO equalizers for multitone DS/SS systems in multipath channels

In [11] the combination of multitone modulation with direct sequence spectrum spreading has been introduced. The performance of a correlation receiver has been evaluated for a multipath channel. In [12] the analysis has been extended to the presence of a multiple access interference. In the present paper we analyze the equalization problem of such a system for a single user scenario. In order to understand the potential of the system we first investigate the steady-state behavior of the MIMO equalizer for an MMSE design. The investigation is carried out for an equalizer following a receiver made of a bank of filters matched to both the symbol shape and the channel, which is a two-path channel. Assuming BPSK symbols an exact expression of the bit error probability before and after equalization is obtained in the form of an integral by means of the characteristic function method. Next adaptive LMS and RLS structures are proposed. The performance of the RLS algorithm is demonstrated.Part of this work has been presented at ICC '95, Seattle, June 1995.This author would like to thank the Belgian NSF for its financial support.This author is a Research assistant of FRIA.     

光纤传输电视伴音的二次调制技术

本文简述光纤传输电视伴音的二次调制技术的基本原理,并对实现二次调制的实际电路进行了详细分析。     

Multi-State Chaos-Shift-Keying Modulation System: Analysis and Realization

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3102JT型工业透平次末级叶片的失效分析

中国石油天然气股份有限公司大庆石化分公司化肥厂尿素装置的3102JT工业透平,多次出现次末级叶片断裂事故。文章对该问题,采用材料化学成分分析、金相分析、断口分析争计算等方法,找出了叶片失效的主要原因并提出了解决方法。     

Performance Monitoring and Assessment of Embedded HW/SW Systems

Performance assessment of embedded HW/SW systems built with various types of VLSI components, i.e. heterogeneous multi-processor architectures, is important to help the development of complex real-time applications. To design such a tool, two issues must be solved: the gathering of relevant information simultaneously on several components without disturbing the application behavior, display of the performance results in a way that can be easily interpreted by designers. This paper presents a significant solution for the two above issues. We first describe what the goal for designers is and what kind of applications are concerned. Then we describe the principle of collecting an event trace and the technique to evaluate the selected performance indexes. The monitoring technique, based on a specific ASIC, is non-intrusive and allows our tool to capture real-time event occurrences from software tasks, and even from hardware functions implemented in ASICs. Each event is automatically time-stamped, collected and processed in real-time to evaluate the performance indexes selected by the designer. We also describe the display tool which clearly shows the results to the designer according to different representations. This technique and the associate real-time performance analyzer are integrated in a complete development process based on the MCSE methodology.     

Integrated sizing and scheduling of wind/PV/diesel/battery isolated systems

In this paper we address the optimal sizing and scheduling of isolated hybrid systems using an optimization framework. The hybrid system features wind and photovoltaic conversion systems, batteries and diesel backup generators to supply electricity demand. A Mixed-Integer Linear Programming formulation is used to model system behavior over a time horizon of one year, considering hourly changes in both the availability of renewable resources and energy demand. The optimal solution is achieved with respect to the minimization of the levelized cost of energy (LCOE) over a lifetime of 20 years. Results for a case study show that the most economical solution features all four postulated subsystems.     

轴系设备故障诊断技巧及经济性分析

基于振动频谱和波形图,本文介绍了转子不平衡、转子不对中、机械松动、摩擦等故障特征,利用相关技巧分析故障诊断过程,提高了分析水平,并对设备故障分析诊断进行经济性分析。     

Statistical optimization of a DC-RF hybrid plasma flow system for in-flight particle treatment

There are many input parameters to control a DC-RF hybrid plasma flow system, such as total gas flow rate, central gas flow rate, swirl gas ratio, RF power and DC power. Furthermore, the interactive effects among these parameters should be considered. In the present study, statistical analysis using simple linear model is conducted to clarify the effects of the input parameters and their interactions on the outputs such as particle residence time and average temperature in a DC-RF hybrid plasma flow system. The thermofluid characteristics of a DC-RF hybrid plasma flow are compared with those of an RF plasma flow. It is shown that the plasma characteristics are changed drastically by adding even small DC power. Furthermore, controllability is also improved by optimizing the operating conditions of a DC-RF hybrid plasma flow system.     

客车发动机在中国的现状和发展趋势

结合我国现有国情,论述客车用发动机:燃油车、混合动力车、电动车、燃料电池和氢燃料车的现状和发展趋势,着重探讨了CNG/LNG车在我国的现状和发展趋势,并对各项动力进行综合比较分析。