查询词典 a power source

for long time, the primary school living to the writing widespread existence "sorrow, afraid, be disgusted with" of thought.but the composition teaching of tradition, the teacher set question from the composition, purpose, choose a material, row to lift a key link to the workbook to review to change, whole one person contract for and resulted in thus student can according to teacher design good"diagram paper" lay bricks, the composition contents be deceitful and empty and lack a kid true, monotonous phenomenon, complete deprival student's workbook of independence power.in fact, composition's being not only be the operation of the language sign.left a person of development, left life, composition will is have no the wood of origin, have no source of water.

长期以来，小学生对写作普遍存在着"愁、怕、厌"的思想。而传统的作文教学，教师从作文命题、立意、选材、列提纲到习作评改，全一人包揽，从而造成了学生只能按教师设计好的"图纸"砌砖，作文内容虚假、空洞，缺乏童真，千篇一律的现象，完全剥夺了学生习作的自主权。其实，作文并非仅是语言符号的操作。离开了人的发展，离开了生活，作文就将是无本之木，无源之水。

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。

Free electron laser is a novel coherent light source. It has a wide tunable ability, a high output power, and a high quality light beam.

自由电子激光是一种新型相干光源，它的激光频率在很宽的范围连续可调谐，输出功率高，具有良好的光束质量。

Since a pentode presents a fairly constant current sink, trying to power it from a constant current source will be fairly unsuccessful, sort of like the unstoppable object hitting the immovable object.

因为五级管本身就表现得类似恒流陷阱，试图用恒流源驱动五级管只会是个失败，就好像试图用一个停不下来的物体去打击一个不可移动的物体。

The method retrenches PLL circuit,not bound by frequency offset and measures the fundamental current accurately when the network voltage is distorted or asymmetric.A simulation model of voltage source high power active power filter system is found in Matlab/Simulink software.

本文在Matlab/Simulink软件中搭建出系统仿真模型，并与采用单个PWM变流器的有源电力滤波器比较，验证了本文设计的方法能够在较低的器件开关频率下实现较好的补偿效果，具有良好的工业应用前景。

One of the transformer windings is connected to a source of ac electric power ,and the second transformer winging supplies electric power to loads .

变压器的绕组之一，是连接到交流电源，第二个是给用电器提供电源。

Hung-fat, director of Shanxi Province Economic and Trade Bureau, the provincial government leadership has repeatedly stressed that the requirements of the province's power plants can no longer take the main source of electricity supply pressure at the local small coal kiln, the quality of the local small coal kiln no guarantee that the supply of instability, although a certain degree of price advantage, but said变就变is not conducive to security and stability of plant production, with the coal industry in our province to implement three major strategies of small coal mines and the implementation of resource integration, requested the power enterprises to adjust the coal supply structure as soon as possible, we must allow for large coal mines to account for more than 50%.

据山西省经委主任洪发科介绍，省政府领导多次强调，要求省内的电厂再不能把电煤供应的主要来源压在地方小窑煤上，地方小窑煤质量没保证、供应不稳定，虽有一定的价格优势，但说变就变，不利于电厂的安全稳定生产，随着我省煤炭行业实施三大战略，对小煤矿实施资源整合，要求电力企业要尽快调整煤炭供应结构，一定要让大矿供的煤能够占到50%以上。

As an important auxiliary machine of turboset, condensing equipment serves as the cold source during thermal circulation of condensing turboset in the power plant and plays an important role in security, economy and operation of the power plant, mainly aiming at condensing the exhaust steam of steam turbine into water, setting up and maintaining a certain vacuum degree in the air extraction outlet of steam turbine, and also conveying condensation water to steam generator so as to reuse.

凝汽设备是汽轮机组的一个重要辅机，在电厂凝汽式汽轮机组的热力循环中，凝汽设备起着冷源的作用，它对整个电厂的安全、经济运行具有重要作用。它的主要任务是将汽轮机排汽凝结成水，在汽轮机排汽口建立与维持一定的真空度；并把凝结水送回蒸汽发生器继续使用。

XGN49-40.5[DXG-40.5] indoors gas insulation metal seal switching gear (hereafter refers to as "sufficient wind chest") is our company introduces the Chinese Electric power Federation Dragon Source Electric power Research institute technology development, the development, the production high tech product, its technical performance satisfies GB/T11022 "High-voltage switch Equipment And Control device Common Specification" and GB3906 "3~35kV Exchange Metal Seal Switching gear" the standard, has high reliable, exempts the maintenance, the occupying a land area of few characteristics; The main technical parameter has achieved the international advanced level.

XGN49-40.5[DXG-40.5]户内气体绝缘金属封闭开关设备是我公司引进中国电力联合会龙源电力研究所技术研制、开发、生产的高科技产品，其技术性能满足GB/T11022《高压开关设备和控制设备的共同技术要求》和GB3906《3～35kV交流金属封闭开关设备》标准，具有高可靠、免维护、占地少的特点；主要技术参数已达到国际先进水平。

This thesis presents a single-phase three-wire photovoltaic energy conversion system. When the proposed system is operating at the maximum power point, the energy is fed to the utility with sinusoidal wave. In low insolation environment, the proposed system operates at the function of active power filter and battery charger. When the utility is fault, the system is disconnected from the utility source.

本文提出一个单相三线式光伏能量转换器系统，使太阳能光伏能量转换器运转於最大功率，将能量以弦波电流送入市电，在无光源时，为主动式电源滤波器的功能，此时可经由市电提供能量对蓄电池充电；当故障时，系统必须与市电解联。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新