查询词典 frequency conversion

The area is small to the highest ( conversion efficiency 13 - 15%, some have achieved more than 20%) of monocrystalline silicon solar energy cell conversion efficiency, and output power is big, and stability is good, grows ( generally can reach more than 20 years ) service life, but the raw and processed material cost height, the weak light specific property is wronger, and production technology is complicated, hence the selling price is also higher; The polycrystalline silicon solar energy cell is basic identical with the function characteristic of monocrystalline silicon solar energy cell; The conversion efficiency of non- brilliant silicon solar cell than hangs down ( simples about 6 - 8%), the area is than greatly, but because of his raw and processed material cost than hanging down, can be easy to big area industrialize production, what will have hope to be used the generally big area to generate electricity from now on most will be this kind of application that battery is along with manufacture technique and new material, in a single day the practical package photoelectricity conversion efficiency of its big area achieves more than the 10-15%, and the price of every tile electric power-generating equipment is fallen 1 - 2 U.S.dollar of time, and just is enough to that the solar energy cell efficiency that big area the getting extensive use will constantly replace in now convention certainly special use and the laboratory of sources of energy s will high get many.

单晶硅太阳能电池转换效率最高（转换效率13～15%，有的已达到20%以上），面积小，输出功率大，稳定性好，使用寿命长(一般可达20年以上)，但原材料成本较高，弱光特性较差，生产工艺复杂，故售价也较高；多晶硅太阳能电池与单晶硅太阳能电池的性能特点基本相同；非晶硅太阳能电池的转换效率较低（约6～8%左右），面积较大，但因其原材料成本较低，可便于大面积工业化生产，今后最有希望用于一般大面积发电的将是这种电池。随着制造技术和新材料的应用，一旦它的大面积实用组件光电转换效率达到10-15%以上，每瓦发电设备的价格降到1～2美元时，便足以大面积得到广泛应用并将不断取代现在常规能源。当然特殊用途和实验室中的太阳能电池效率要高得多。

The present dissertation deals with:(1) Exploring the feasibility of the CO〓 methanation and the conversion CH〓/H〓 into C〓 hydrocarbons under plasma with catalyst at ambient temperature and atmosphere.(2) Designing a reactor and preparing some catalysts suited for the conversion of carbon dioxide via the cooperation effect of plasma and catalysts.(3) Optimizing reaction conditions of conversion carbon dioxide to C〓 hydrocarbons in the proposed process.(4) Studying the reaction mechanism of conversion carbon dioxide to C〓 hydrocarbons under plasma by using in situ OES technology.(5) By the results of characterizing coked catalysts, exploring the reasons that result in the coking of catalyst and the paths for decreasing the deposit in the catalyst under plasma.(6) Analyzing the energy efficiency of the plasma catalysis and exploring the paths for improving the energy efficiency.

论文的主要研究工作包括：（1）探索脉冲电晕等离子体与催化剂共同作用CO〓／H〓甲烷化和由CH〓/H〓合成C〓烃反应的可行性；（2）研制等离子体催化CO〓转化的反应器和适配的催化剂；（3）优化等离子体催化CO〓转化制C〓烃反应的工艺条件和电参数；（4）利用原子发射光谱原位技术对等离子体反应的诊断结果，对等离子体催化CO〓转化制C〓烃反应的机理进行推断；（5）通过对积碳催化剂的表征结果，分析积碳的类型及其成因，并探讨减少积碳的途径；（6）通过对等离子体催化CO〓转化制C〓烃反应能量效率的分析，探讨提高等离子体催化反应能量效率的途径。

This design paper introduced one kind based on the DSP chip entire numerical control single-phase frequency changer design, along with the frequency conversion velocity modulation technology unceasing development, the frequency changer application is more and more widespread, the frequency changer besides has the remarkable velocity modulation performance, but also has the remarkable energy conservation function, is the enterprise technological transformations and the

本设计论文介绍了一种基于DSP芯片的全数字控制单相变频器的设计，随着变频调速技术的不断发展，变频器的应用越来越广泛，变频器除了具有卓越的调速性能之外，还有显著的节能作用，是企业技术改造和产品更新换代的理想调速装置。

This design paper introduced one kind based on the DSP chip entire numerical control single-phase frequency changer design, along with the frequency conversion velocity modulation technology unceasing development, the frequency changer application is more and more widespread, the frequency changer besides has the remarkable velocity modulation performance, but also has the remarkable energy conservation function, is the enterprise technological transformations and the product renewal ideal speeder.

本设计论文介绍了一种基于DSP芯片的全数字控制单相变频器的设计，随着变频调速技术的不断发展，变频器的应用越来越广泛，变频器除了具有卓越的调速性能之外，还有显著的节能作用，是企业技术改造和产品更新换代的理想调速装置。

This paper bases on frequency-hopped and frequency synthesis theories, and through demonstrating three schemes of frequency synthesis, the paper selects one of these schemes that uses DDS spiriting up PLL and improves on the method according to the practical target and synchronously, the paper analysis the capability of the output signal and the conversion time of the frequency.

本文在对跳频理论及频率合成理论分析的基础上，在讨论三种频率合成方案后，设计完成了一种适于本课题的DDS激励PLL的混合方案，并对频率合成器主要性能中的输出信号的噪声特性和频率转换性能做了研究分析。

Based on the requisition of wireless system debugging, this paper develops a novel radio-frequency beaconing. Design method and system constitution of a novel beaconing based on PLL IC PE3336 are given, and the accomplish method of the system's hardware and software arc expounded. The test results show that the beaconing adopted in this method has a reliable and stable frequency conversion features. The more applications in the wireless system find that the users can set necessary frequency conveniently. Especial1, the friendly man-machine interface makes the operation is more flexible. It is as excellent performance-price-ratio beaconing, and as a signal source, it can be used in the research and the debug procession of variable radio-frequency components.

根据无线电数据链系统及部件的调试需要，研制开发了一种新型的以锁相环为核心、由单片机控制的射频信标机；文中给出了基于锁相环芯片PE3336的新型信标机的设计方法与系统组成，阐述了系统硬件及软件的具体实现为法；测试结果表明，利用该方法设计的信标机具有稳定、可靠的变频特性，且各项指标均达到了要求；进一步在某无线电系统中的应用发现，用户可方便地设置所需频点；特别是友好的人机界面，使用户操作更为灵活方便，是一种性能价格比优良的信标机；并可作为信源用于不同的射频部件研制与调试过程中。

The results demonstrated that the fractional conversion and reaction rate were rapidly increased in the initial curing reaction. The higher the curing temperature, the higher the fractional conversion and reaction rate was. With increasing of the curing temperature and time, the fractional conversion and reaction rate decreased and became constantly. The initial curing reaction was a first order reaction. The apparent activation energy and frequency factor of curing reaction used G- capryl ester was bigger than that of used G-oligomer.

结果表明：固化体系在研究的固化温度下，转化率和反应速率在固化反应初期增加快速，温度越高增加越快，随着固化时间的延长，这种变化逐渐变慢，并最终趋于恒定；初期固化反应为一级反应，反应初期的表观活化能和指前因子大小顺序为G-预聚体＞G-辛酯。

This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立国防科学技术人学研究生院学位论文三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

Simulation results show that, for the fixed sampling frequency, the error rises with the frequency increasing of periodic signal, and decreases with the attenuation time constant increasing of non-periodic signal. The sampling frequency determines the upper limit of appropriate frequency band directly. The research provides the basis for the selection of cutoff frequency in filter design.

仿真结果表明，在采样频率确定时，对于周期信号，计算误差随频率的增加而增大，而对于非周期信号，计算误差随衰减时间常数的增大而减小，采样频率大小决定了插值法用于分布参数模型的适用频带上限，该研究为滤波器设计中截止频率的选择提供了依据。

This experiment is in frequency adjustment X-mitter about that miniwatt frequency adjustment X-mitter operating principle, analyses the debugging making method and their installation, the microphone changes implication into an audible signal, wave an audible signal being modulated as a result of enlarging the day afer tomorrow being in progress to the carrier wave , producing frequency adjustment, by the fact that air wire launching the frequency adjustment electromagnetic wave to the outside , the radio set just can with frequency adjustment meet hear clear implication.

本毕业设计是关于小功率调频发射机工作原理、分析制作方法及其安装调试，在调频发射机中，话筒将话音转化为音频信号，音频信号经放大后对载波进行调制，产生调频波，通过天线向外发射调频电磁波，用调频收音机便可以接听到清楚的话音。

Who? I never heard of him, Paul said, before asking teammate James Posey if he had heard of him.

赛后，科比说，他一直都是一名非常出色的射手，今天他打得很棒。

When I joined the company, I rotated around the different sections.

我加入这个公司时，轮换过几个不同的部门。