查询词典 the current of time

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

This high voltage electrostatic precipitation controller has 7 channels of analog input,2 channels of analog output, 12 digital inputs and 16 digital outputs. The analog input includes primary current, secondary current, primary voltage, secondary voltage, etc. Controller uses MAX 187 as the A/D converter, which ensure the sampling speed and the conversion precision in the same time. The processor unit is RCM2250 module. Rabit 2000 processor, a 128K SRAM and a 256K Flash Rom are integrated in RCM2250, which improves the performance of pricipitation controller. MAX504 is used to produce the 4~20mA current output.

模拟量输入采集的信号有升压变压器一次电流、一次电压、二次电流、二次电压等，采用12位逐次比较式A/D转换器MAX187，兼顾采样速率和转换精度；中央处理单元采用以8位嵌入式处理器Rabbit2000为基础的RCM2250模块，外扩128KSRAM和256K Flash ROM，内部资源丰富，提高了控制器的整体性能；模拟量输出采用内带基准源的10位电压输出数模转换器MAX504，实现了标准4～20mA电流信号输出；控制器通过控制算法在相应开关量点上输出可控硅的触发脉冲。

In the power supply circuit, series power supply and the adjustment of the series load, the load current flows through all of the adjustments, and transistors Guozainaili worse, once output overload or short circuit, the input voltage increases in the full set of adjustment an emitter, the current surge to adjust the fierce heat, if not over-current protection measures at this time, the adjustment will be burned, power Zhengliuguan also will be greatly threatened or damaged.

中文摘要：在稳压电源电路中，串联型稳压电源的调整管与负载串联，负载电流全部流经调整管，而晶体管的过载能力较差，一旦输出端过载或短路，输入电压全部加在调整管集---射极间，其电流剧增，使调整管猛烈发热，如果此时没有过流保护措施，调整管就要被烧坏，电源整流管也将受到巨大威胁或损坏。

A class of fast-scale bifurcations appearing around the maximum value of the input voltage is discovered for the first time by experiment. Then the influence of the fast-scale bifurcations on the performance of the PFC converters is discussed. Whether the fast-scale bifurcations will appear and how wide the bifurcation region depend on the characteristics of the current loop output. Therefore, the main factors that affect the current loop output are analyzed, including the current loop parameters, inductance, and root-mean-square value of the input voltage.

通过实验，该文首次发现了一类在输入电压最大值附近发生的快时标分岔；详细讨论了快时标分岔对PFC变换器性能的影响；由于电流环输出的特点决定了变换器是否会出现快时标分岔以及分岔区域的大小，该文分析了影响电流环输出的主要因素，包括电流环参数、电感值和输入电压有效值。

Next, in chapter 3, we compare the current densities in inversion region and accumulation region of the RTO oxides with and without ANO-DAC. We found that the leakage current in inversion region is smaller with ANO-DAC compensated, but the current density lowering is slower with time past.

接著，在第三章我们对无阳极氧化与经过阳极氧化补偿后的氧化层做比较，比较在反转区与聚积区的电流密度，发现在阳极氧化补偿后反转区虽有比较小的漏电流，但随著时间经过，电流降低速度比较慢。

So we designed a adaptive synchronizing controller based on hereinbefore hardware environment: first a small magnitude reference signal r is outputted to system through the signal card (to ensure that the vibrating system works in a linear state), and this signal is sent to the moving coil of vibrator through the power amplifier, so vibration is produced through electromagnetic induction. Secondly the vibration signal can feedback to the data acquiring card in the servo system through the acceleration sensor on the Vibroseis reactor M〓 and the base-plate M〓, then the computer can get the current vibrating state y〓 of the coil of vibrator according to the feedback information from the data acquiring card, and give a real time comparing between the current state y〓 and the reference output y〓 of the set-in reference model with current reference input being r , then regulates the correlative controlling parameters according to the error e〓=y〓-y〓 till y〓→y〓, finally normal signal sweeping begins with a certain phase fixed. Meanwhile a synchronization signal for seismic signal record is sent to seismograph from synchronization signal outputting component in the Vibroseis system to perform the controlling process of synchronization of sweeping phases.

为此，我们基于以上的硬件环境设计了一个自适应同步控制器：首先通过信号发生卡对系统输出小幅度的参考信号r(从而保证振动系统工作处于线性状态)，信号通过前置放大器、功率放大器等送到激震器动圈，并通过电磁感应产生振动，振动信号通过可控震源激震器反应块M〓和基板M〓上的加速度传感器反馈给伺服系统中的数据采集卡，工控计算机根据采集卡的反馈信息，获取当前激震器动圈的振动状态y〓，并实时地将该状态与内置的参考模型在当前参考输入r下的参考输出y〓进行辨识，再将两者输出误差e〓＝y〓-y〓对系统的有关控制参数进行调整，直至y〓→y〓，最后在经过某一固定的相位后，开始信号的正常扫描过程，与此同时，由可控震源系统的同步信号输出部件向地震仪送出一地震信号记录同步信号，进而完成扫描相位同步控制过程。

Electric motor or lamps and lanterns with nastic movement start with minor impedance,and bigger electric current, after installation of the electric saver, the starting current can be reduced significantly, and at the same time, reducing the running current of the light load motor or lamps and lanterns.

电动机或感性灯具在起动时阻抗极小，启动电流较大，安装节电器后，可大大降低起动电流，同时可降低轻载电机及灯具的运行电流。

The results show that Sb addition can diminish the crystal grain, but the content of segregative phase at crystal boundary increases, and the current efficiency of material is low. Compared with Sb addition, Sn addition can also diminish the crystal grain, the current efficiency increases, the content of segregative phase at crystal boundary reduces, but diffusional corrosion of the anode surface is not uniform. The cooperation of Sb and Sn can prevent Si from segregating effectively and enhance the current efficiency obviously. At the same time, anode materials have preferable surface dissolution characteristics.

结果表明： Sb具有细化晶粒的作用，但晶界存在较多偏析相，电流效率偏低；与Sb相比较， Sn也具有细化晶粒的作用，电流效率有所提高，晶界偏析相较少，但阳极的表面腐蚀溶解不均匀； Sn和Sb的协同作用在于能有效地抑制Si的偏析，显著提高阳极的电流效率，使得阳极表面具有良好的腐蚀溶解性。

As part of the study of social administration of Nanjing in the Republic of China, the thesis consists of 7 chapters: Chapter one explains the basic concepts of social administration and the development of modernization of Nanjing before 1927. It stresses the importance of social administration in city development through the depiction of social characteristics and problems of Nanjing. Chapter 2 introduced the theory of social administration of the Republic of China, under which the municipal institutions are structured. It focuses on the social theory of Sun Yat-sen and correlative comments of Jiang Kai-shi, which reflect the theoretic level and subjective intention of social reform of the Republic of China. Chapter 3 discusses the local autonomy of Nanjing of the Republic of China. The origin of democratic local autonomy theory and its influence over social administration are expatriated. The advantages and disadvantages of local autonomy are analyzed in detail. Chapter 4 focuses its discussion upon social rescue work, an important part of social administration, with general description of social rescue work in Nanjing and concludes the characteristics of social rescue work in the transition from the traditional to the modern society. Focusing on the prominent problem of the large flows and inflation of population of Nanjing, chapter 5 discusses the population and population management of Nanjing and outlines the population situation through analysis of the population problem, management methods and the current situation. Chapter 6 describes the unprecedentedly active citizen organizations and parties. The transform and changes of these organizations occurring under the new circumstances and their functions in social administration are analyzed to reveal the interactive function between government and social organizations in social administration. Chapter 7, the epilogue, makes theoretic evaluation of the characteristics of social administration and its revelation to the current society of Nanjing, hoping this research serves as a reference to the current time.

本文是民国南京社会管理研究的一个部分，由七个章节组成：第一章介绍了社会管理的基本概念和1927年以前南京社会近代化的变迁过程，通过对南京社会特点和社会问题的描述，阐明了社会管理在城市发展中的重要作用；第二章介绍了民国社会管理思想的基本内容和在此指导下的南京市政府有关机构的设置，着重阐述了孙中山的社会管理思想和蒋介石的有关论述，反映了国民政府的社会管理的认识水平及其实行社会改造的主观意图；第三章专题讨论了民国南京地方自治，对具有近代民主意义的地方自治思想的由来及其社会管理意义进行了阐述，具体分析了南京推行地方自治的利弊得失；第四章将社会救济事业作为社会管理的一项重要内容进行了讨论，描述了南京社会救济事业的基本概况并对从传统向近代过渡社会救济事业的若干特点进行了总结；第五章针对南京城市人口的大量流动和急剧膨胀这一突出的社会问题，集中讨论了南京的人口与人口管理，通过对南京人口问题、管理手段以及人口状况的分析，展示了南京人口构成的基本面貌；第六章描述了南京空前活跃的市民组织和社会团体，着意反映这些社会组织在新的条件下的转型和变化，分析其在社会管理中所发挥的作用，企望由此揭示政府与社会组织在社会管理中的互动作用；第七章为结语，对南京社会管理的特点及其对现实的启示进行了理论评价，力求本研究更能具有现实借鉴意义。

The basic relationship between the the first half-wave peak value of transient current and the initial firing angles is found by means of analytical method.The practical method is put forward to determine the initial two-phase and the third phase firing angles with the limiting value and the space vector varying track of transient current.And then the subsequent series of firing angles with the even step are calculated by using the speed at the time of re-switching.The suppressive effect to the inrush current is verified with simulation and experiment of rapid soft re-switching control,by which the influence of different speed to rapid soft re-switching course is analyzed besides.3 To analyze the power loss for typical periodically variable running load and deeply study the energy-saving principle and control mode of the intermittent power supply approach. Futhermore,the novel integrated energy-saving control technique is developed on base of the intermittent power supply approach.

通过解析方法找到快速软投入初始触发角与瞬态电流首半波峰值加热板之间的基本关系，进而提出了由限流值和空间向量轨迹确定初始两相和第三相触发角的方法，并以固定步长均匀递减的方式由投入时转速计算出其它后续触发角；结合仿真和实验验证了快速软投入对冲击电流的抑制作用，并分析了不同转速下投入时对电源快速软投入过程的影响。3对典型周期性变工况负载特性进行能耗分析，深入研究断续供电节能机理和控制模式，并进一步发展了以断续供电为主的综合节能控制新技术。

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。