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A method of a voice annunciator system is introduced in this paper. To solve the problems existing in the traditional industry annunciator, with AT89C52 microcontroller as the main control unit, the voice annunciator system is designed by ISD4003-4 which is made of ISD company in America. Furthermore, the hardware circuit design and software programs are discussed in detail.

介绍了一种语音报警系统的设计方法，该语音报警系统针对传统工业报警器中存在的问题，以AT89C52单片机为主控单元，采用了美国ISD公司的ISD4000系列语音芯片ISD4003-4设计了该系统的语音录放电路，对硬件电路的设计及软件的编程作了较为详细的阐述。

This paper analyzed and researched the characteristics of Schmitt trigger, single-stable-state trigger and astable multivibrator constituted by 555 timer based on PSPICE. Against the phenomenon of astable multivibrator constituted by 555 timer has no oscillation in PSPICE, an effective analysis method was brought out for 555 timer circuit to simulate the actual oscillator.

作者在文中应用PSPICE对555定时器构成的施密特触发器、单稳态触发器和多谐振荡器的工作特性进行了仿真分析和研究，针对PSPICE中555定时器构成的多谐振荡器不起振的问题提出了模拟振荡电路的有效起振方法，对电子电路的分析与设计具有一定的参考意义。

Based on the analysis of micro -bolometer resistance -temperature characteristics, a new readout circuit was proposed. It allowed micro -bolometer operate without a temperature stabilizer over a wide range of ambient temperature. And it need a Flash memory to store the correcting factors of different temperatures and a temperature sensor to detect the ambient temperature of the micro -bolometer. By utilizing the factors in the Flash memory, Digital Analog Converter controls the micro -bolometer bias current to compensate the fluctuation of ambient temperature.

通过对微测辐射热计的电阻温度特性的分析，设计了一种新型无需温度稳定装置的读出电路，该电路的Flash存储器存储不同温度下的校正系数，温度传感器实时检测探测器的环境温度，从Flash中取出相应的温度校正系数送入数模转换器，通过DAC的电压输出来控制探测器偏流以进行环境温度补偿。

Then,the paper analyzes common-mode voltage and output voltage range of operational amplifier influenced by temperature and process problems that may appea.

基于混沌、均匀分布的真随机数发生器的工作电路和精度要求较高的电压参考电路的温度漂移进行分析，给出了仿真得到的温度曲线；分析了工艺中可能存在的问题和温度的影响与运放的共模电压和输出电压幅度，以及与混沌公式直接相关的开关电容等，根据最坏分析得到混沌公式，给出了仿真测试结果。

Simultaneously the model of bipolar junction transistor and CMOS transistor and the basic circuit units such as current mirrors are briefly introduced; with the topology and model circuit ,the principle and feature of the CC are analyzed. The applications of the CC in the fields of the active network and signal process are synthesized.

首先介绍了模拟集成电路在当代社会中的重要性和集成电路研究的必要性，并简要地介绍了双极型晶体管和CMOS晶体管的模型结构以及几种电流镜电路的原理及性能；从电流传送器的拓扑结构入手，在给出其模型电路的基础上，介绍了电流传送器的工作原理。

The specific discussion of the core oscillation circuit design process, Integration of the 555 timer gave a detailed analysis.

常见的耐压测试仪往往价格昂贵不易携带，因此我们设计了简单便携式耐压测试仪来测试半导体器件的耐压值，介绍了耐压测试仪的电路组成及原理，具体讨论了其核心部分振荡电路的设计过程，对集成定时器555做了详细的分析。

Compared with tranditional methods, it is not too optimistic or pessimistic, fit for the exact timing of high-speed circuit design. Anda retiming scheme based on the above method is also presented to optimize the timing behavior of sequential circuits.

同传统方法相比，本方法计算出的最小周期既能保证电路的正确计算，又不至于保守，而且能同时计算出组合逻辑部分的延迟；然后从时序电路的波形多项式出发，进一步给出了多周期敏化的最小时钟周期确定方法，适用于有苛刻定时要求的环境。

In this paper, we have conducted some experiments on the ISCAS89 benchmarks that are in form of EDIF. We compare FEAS algorithm, FEAS plus algorithm and algorithm based on classify paths on running time. Those algorithms are implemented in C language. At last we conclude that our algorithms can achieve retiming transforming quickly.

本文实验以ISCAS89标准测试电路的EDIF网表为输入数据源，通过编写C程序对FEAS算法、改进的FEAS算法和基于路径分类的重定时算法进行对比，结果表明我们的算法能够快速完成同步时序电路的重定时变换。

How to control level and temperature of material container is common issue of the automation design in chemical industry. In the paper, control configs of level and temperature in detail were analyzed, fault of the existing configs was found and the updated config which contains self-maintenance circuit and interlocking circuit was risen.

物料容器的液位和温度等工艺变量控制是自控工程设计中经常遇到的问题，文章针对液位和温度工艺变量控制方案的关键内容分别进行详细分析，发现现有方案存在的缺陷和误区，提出了自保持电路加互锁电路的改进方案。

If we assume that we can tolerate errors of no more than 0.5 LSB, this calculation tells us that in a 16-bit SYSTEM with 10 V FS we must KEEP the total error to less than 76 pV, which is approximately equal to the thermo- ELECTRIC voltage in a nichrome wirewound RESISTOR with copper/nickel leads having about 2℃ temperature difference between its ends.

假设电路的噪声必须小于0.5LSB，按照前面的计算，这意味着在10V量程的电路中必须将噪声控制在76uV以下，而这个电压大致与线绕电阻的两个引脚间温差2C时的热噪声相当。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。