燃煤废气中RAHs的分析

本文主要阐述用ＨＰＬＣ及ＧＣ／ＭＳ分析燃煤废气中ＰＡＨｓ的全过程，发现其ＰＡＨｓ普遍高于汽车及柴油机尾气中的含量，同时利用ＧＣ／ＭＳ鉴定了６９种ＰＡＨｓ、氮 ＰＡＨｓ及甲基化ＰＡＨｓ。     

GC8型在线气相色谱GC8P—GC8A间通信线路的干扰对策

本文介绍了ＧＣ８Ｐ－ＧＣ８Ａ间通信线路出现干扰的几种形式，以及相应的对策。     

大动态范围PGA电路的设计与实现

本文通过理论分析与实验研究，介绍了一个大动态范围ＰＧＡ电路的设计与实现过程，并从理论和实践上证明：大动态范围ＰＧＡ电路是压缩大动态模拟信号动态范围并可提高信号检测精度的一种行之有效的技术方案。     

NEW APPROACHES FOR COMPUTING DYNAMIC LOAD-CARRYING CAPACITY OF MULTIPLE COOPERATING ROBOTIC MANIPULATORS

ＮＥＷＡＰＰＲＯＡＣＨＥＳＦＯＲＣＯＭＰＵＴＩＮＧＤＹＮＡＭＩＣＬＯＡＤＣＡＲＲＹＩＮＧＣＡＰＡＣＩＴＹＯＦＭＵＬＴＩＰＬＥＣＯＯＰＥＲＡＴＩＮＧＲＯＢＯＴＩＣＭＡＮＩＰＵＬＡＴＯＲＳ①ＹａｎｇＹｕｌｉｎＬｕＬｉｎｇＺｈａｏＹｏｎｇｓｈｅｎｇＺｈｏ...     

RELIABILITY-BASED SYNTHESIS OF PATH GENERATING LINKAGES

ＲＥＬＩＡＢＩＬＩＴＹ－ＢＡＳＥＤＳＹＮＴＨＥＳＩＳＯＦＰＡＴＨＧＥＮＥＲＡＴＩＮＧＬＩＮＫＡＧＥＳＲＥＬＩＡＢＩＬＩＴＹ－ＢＡＳＥＤＳＹＮＴＨＥＳＩＳＯＦＰＡＴＨＧＥＮＥＲＡＴＩＮＧＬＩＮＫＡＧＥＳＳｈｉＺｈｏｎｇｘｉｕ；ＬｉＣｈｅｎｇｇａｎｇ；Ｙ...     

INVESTIGATION ON BRITTLE FRACTUREPROPAGATION－ARRESTING CHARACTERISTICS OF STEEL PIPE

ＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＢＲＩＴＴＬＥＦＲＡＣＴＵＲＥＰＲＯＰＡＧＡＴＩＯＮ－ＡＲＲＥＳＴＩＮＧＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＳＴＥＥＬＰＩＰＥＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＢＲＩＴＴＬＥＦＲＡＣＴＵＲＥＰＲＯＰＡＧＡＴＩＯＮ－ＡＲＲＥＳＴ...     

IMPROVEMENTS ON THE CONFIGURATION AND OPTIMUM PARAMETERS OF HIGH一SPEED THRUST BEARINGS

ＩＭＰＲＯＶＥＭＥＮＴＳＯＮＴＨＥＣＯＮＦＩＧＵＲＡＴＩＯＮＡＮＤＯＰＴＩＭＵＭＰＡＲＡＭＥＴＥＲＳＯＦＨＩＧＨ一ＳＰＥＥＤＴＨＲＵＳＴＢＥＡＲＩＮＧＳＩＭＰＲＯＶＥＭＥＮＴＳＯＮＴＨＥＣＯＮＦＩＧＵＲＡＴＩＯＮＡＮＤＯＰＴＩＭＵＭＰＡＲＡＭＥＴＥＲ...     

CAGD AND NC MILLING OF THE CASTING MOULD OF HELICAL INTAKE PORT

ＣＡＧＤＡＮＤＮＣＭＩＬＬＩＮＧＯＦＴＨＥＣＡＳＴＩＮＧＭＯＵＬＤＯＦＨＥＬＩＣＡＬＩＮＴＡＫＥＰＯＲＴＣＡＧＤＡＮＤＮＣＭＩＬＬＩＮＧＯＦＴＨＥＣＡＳＴＩＮＧＭＯＵＬＤＯＦＨＥＬＩＣＡＬＩＮＴＡＫＥＰＯＲＴＭａＸｉａｎｇｙａｎｇ；ＱｉＷｅｎｘｉｎｇ...     

STUDY ON THE INCREASE OF SLOPE-WALKING ABILITY OF MULTI－LEGGED ROBOT

ＳＴＵＤＹＯＮＴＨＥＩＮＣＲＥＡＳＥＯＦＳＬＯＰＥ－ＷＡＬＫＩＮＧＡＢＩＬＩＴＹＯＦＭＵＬＴＩ－ＬＥＧＧＥＤＲＯＢＯＴＳＴＵＤＹＯＮＴＨＥＩＮＣＲＥＡＳＥＯＦＳＬＯＰＥ－ＷＡＬＫＩＮＧＡＢＩＬＩＴＹＯＦＭＵＬＴＩ－ＬＥＧＧＥＤＲＯＢＯＴＸｕＰｅｉｊｕ...     

ECCENTRIC CIRCULAR GROOVE LAPPING TECHNIQUE FOR CERAMIC BALLS

ＥＣＣＥＮＴＲＩＣＣＩＲＣＵＬＡＲＧＲＯＯＶＥＬＡＰ－ＰＩＮＧＴＥＣＨＮＩＱＵＥＦＯＲＣＥＲＡＭＩＣＢＡＬＬＳＥＣＣＥＮＴＲＩＣＣＩＲＣＵＬＡＲＧＲＯＯＶＥＬＡＰ－ＰＩＮＧＴＥＣＨＮＩＱＵＥＦＯＲＣＥＲＡＭＩＣＢＡＬＬＳＲｅｎＣｈｅｎｇｚｕ，ＸｕＹａ...     

Modeling and analysis of steady-state vibration induced by backlash in servo rotary table

Backlash cannot be always avoided in mechanical systems because of wear or looseness. Steady-state vibration may be induced by backlash in closed loop feed drive systems. This paper presents a mathematical model of a servo rotary table, considering the effect of backlash. The accuracy of this model is verified by an experiment. The influences of the parameters, such as position controller gain, velocity controller gain, load and the magnitude of backlash, on steady-state vibration are discussed. The steady-state vibration amplitude increases with the position controller gain, load and the magnitude of backlash. The steady-state vibration frequency increases with the position controller gain and the velocity controller gain, while an increase in load leads to a decrease in the frequency.     

A study of a short-term instability and aging of ΦЭУ-115M photomultiplier tubes

Results of studying the instability of the gain of ΦЭУ-115M photomultiplier tubes (PMTs) at a varying count rate corresponding to the range of the anode current of 0.02–120 μA are presented. It is shown that the behavior and value of the gain instability for different specimens of this PMT type substantially differs when the count rate changes. The relative change in the gain of some PMTs reaches 23%. Results of the study of the long-term behavior of the PMT gain in high-rate conditions (PMT aging study) are given. The relative gain drop is 30% after an anode charge of ～600 C is accumulated.     

Determination of all feasible robust PID controllers for open-loop unstable plus time delay processes with gain margin and phase margin specifications

This paper proposes a novel alternative method to graphically compute all feasible gain and phase margin specifications-oriented robust PID controllers for open-loop unstable plus time delay (OLUPTD) processes. This method is applicable to general OLUPTD processes without constraint on system order. To retain robustness for OLUPTD processes subject to positive or negative gain variations, the downward gain margin (GM_down), upward gain margin (GM_up), and phase margin (PM) are considered. A virtual gain-phase margin tester compensator is incorporated to guarantee the concerned system satisfies certain robust safety margins. In addition, the stability equation method and the parameter plane method are exploited to portray the stability boundary and the constant gain margin (GM) boundary as well as the constant PM boundary. The overlapping region of these boundaries is graphically determined and denotes the GM and PM specifications-oriented region (GPMSOR). Alternatively, the GPMSOR characterizes all feasible robust PID controllers which achieve the pre-specified safety margins. In particular, to achieve optimal gain tuning, the controller gains are searched within the GPMSOR to minimize the integral of the absolute error (IAE) or the integral of the squared error (ISE) performance criterion. Thus, an optimal PID controller gain set is successfully found within the GPMSOR and guarantees the OLUPTD processes with a pre-specified GM and PM as well as a minimum IAE or ISE. Consequently, both robustness and performance can be simultaneously assured. Further, the design procedures are summarized as an algorithm to help rapidly locate the GPMSOR and search an optimal PID gain set. Finally, three highly cited examples are provided to illustrate the design process and to demonstrate the effectiveness of the proposed method.     

掺铒光纤超荧光光源外部增益平坦技术的研究

为满足光纤布拉格光栅传感和波分复用光纤通信系统对光源光谱平坦度与带宽的要求,利用外部增益平坦技术实现掺铒光纤超荧光光源输出光谱的平坦化。介绍了三种常见的外部增益平坦技术,并通过实验对平坦结果进行比较,由此得出采用长周期光栅增益平坦滤波器是一较好的选择。实验结果表明,平坦波段范围内(1 525~1 540nm)的光谱不平坦度小于±1.1dB,整个C波段光谱的3dB带宽为39.125nm。     

可变增益放大器的实现方法

从应用的角度出发,给出了典型的可变增益放大器的实现方法,总结了实现方法的特点,探讨了实现方法在具体应用中的一些重要的技术问题。     

Combined gain and phase margins

In this note, the limitations of conventional or separate gain or phase margin are shown. Then, the combined gain and phase margins are introduced to overcome the limitations and suit both stable and unstable systems. A simple method for their computation is presented and their applications in stabilization is demonstrated.     

CMOS图像传感器光子转移曲线辐照后的退化机理

针对EMVA 1288标准测试辐照后互补金属氧化物半导体(CMOS)图像传感器的重要性能参数(光子转移曲线和转换增益)适用范围受限的问题,提出了针对辐照后CMOS图像传感器光子转移曲线和转换增益的改进的测试方法。该方法通过调整测试条件,限制辐照后CMOS图像传感器的暗电流和暗电流非均匀性噪声,求解出辐照后正确的器件性能参数,从而直观地得知辐照所引起的器件性能变化。利用该方法进行了实验测试,结果显示:辐照导致转换增益比辐照前退化了7.82%。依据此结果分析了辐照导致光子转移曲线和转换增益退化的机理,认为转换增益的退化是由于质子辐射引起的电离效应和位移效应导致暗电流、暗电流非均匀性增大所致。本文为掌握CMOS图像传感器的空间辐射效应提供了理论基础。     

Optimal Predicted Fuzzy PI Gain Scheduling Controller of Constant Turning Force Systems with Fixed Metal Removal Rate

The dynamic behaviour of the turning process is nonlinear and time-varying owing to variations in cutting depth. This paper proposes an optimal predicted fuzzy PI gain scheduling controller to control the constant turning force (CTF) process with a fixed metal removal rate (MRR) under various cutting conditions. The predicted fuzzy PI gain scheduling control scheme consists of two parts: the fuzzy PI gain scheduling controller; and the grey predictor. First, the optimal parameters of both the grey predictor and the optimal PI gains corresponding to each desired cutting depth in the range of operation, are designed off-line by using the proposed optimal combined method, i.e. Taguchi–RGA method, which integrates the Taguchi method and a real-coded genetic algorithm (RGA). Then, before the parameters of both the grey predictor and the PI gains are scheduled on-line, by fuzzy inference in terms of the changes of cutting depth, the optimal set of triangular-type membership functions of the fuzzy inference mechanism for scheduling the parameters of both the grey predictor and the PI gains are also designed off-line by using the Taguchi–RGA method. Computer simulations are performed to verify the applicability of this optimal predicted fuzzy PI gain scheduling control scheme for controlling the CTF process with a fixed MRR under various cutting conditions. It is shown that such an optimal predicted fuzzy PI gain scheduling control scheme can achieve satisfactory performance and better results than those reported recently in the literature.     

Centralized PI controllers for interacting multivariable processes by synthesis method

In this article, two methods of designing a centralized control system for multi-input, multi-output (MIMO) processes are presented. Centralized proportional-integral (PI) controllers are designed based on a direct synthesis method. The inverse of the process transfer function matrix in the direct synthesis method is approximated based on the relative gain array concept. The method is further improved by using a relative normalized gain array, and an equivalent transfer function for each element in the process transfer function matrix is derived for the closed-loop control system. The transpose of the effective transfer function is used to approximate the inverse of the process transfer function matrix. The simulation studies demonstrate the effectiveness of this method. The proposed centralized controllers reduce the interactions better than recently reported decentralized controllers do. A centralized controller designed based on a relative normalized gain array (RNGA) gives a better performance than a centralized controller designed based on a relative gain array (RGA).     

一种新型增益自适应Smith预估器

在Smith预估器的基础上加入增益自适应，构成了一种新型增益自适应Smith预估器，并针对一阶惯性加纯时滞过程,给出了增益自适应算法。对一阶惯法和二阶惯性加纯时滞过程进行了仿真。结果表明，新型增益自适应预估器对模型结构与参数的精度均无过高的要求，从而有很高的应用价值。