查询词典 Ld.

According to the need of continuous LD parameter analyzer,a new continuous LD driver control system is developed.

针对连续半导体激光器特性参数测试的需要，研制了一种新型的连续LD驱动控制系统。

The stable and reliable operation voltage of the probe can be given by the following methods:(1) 20% light coupling efficiency is obtained by direct coupling of LD-optical fiber.(2) The light power is transmitted by multi-model optical fiber.(3) The largest photo-electric conversion efficiency is achieved by selecting the transformer regulation of step-up transformer.(4) The stable light intensity is achieved by using LD light feedback of driving circuit and refrigeration.

通过下述方法可提供稳定、可靠的探头工作电压：LD—光纤的直接耦合方式，可实现20％左右的光耦合效率；采用多模光纤传输功率；选择升压变压器最佳变比提高光电转换效率；采取LD驱动电路光反馈以及致冷措施使其发光幅值稳定。

H.伸缩环转动环伸缩环垫片前轴封 S D / L D / S L M E C H A N I C A L S E A L P U M P S SD/LD/SL SERIES PUMPS The SD/LD/SL series are dependable, self priming pumps. The full motor horsepower is translated into fow via the shaft. These pumps are used for a wide range of applications, from chemical transfer to process solution recirculation to waste treatment. This series is capable of self-priming up ro 20 feet of lift. The mechanical seal is a self-cooling, Tefon bellows which is cooled by the solution being pumped. The construction materials and seals avaiable make this pump extremely versatile. The horizontal design has a working temperature from167℉ to 194℉(75℃ to 90℃), depending on the material of construction, and can handle most chemical solutions. The SD/LD/SL series pumps are designed to run outside the tank or process module. The SD/LD series pumps incorporate a FRPP molded base, legs and pump-to-motor casing. There are no bolts or metallic parts in contact with the solution being pumped.

SD/LD/SL泵是可靠的自吸泵，马达全部的马力经由轴心完全转化为流量，此型泵广泛地使用於从化学药水循环或加工溶液循环到废水处理等各种用途，此型泵可自吸达20英呎，机械轴封是自我冷却的，经由抽送的溶液来冷却，可供应的不同结构材质及轴封使此种泵的用途非常多样化，依其结构材料的不同，其卧式设计的工作温度由75℃到90℃(167℉到194℉)，而且可处理绝大部份的各种溶液，SD/LD/SL是设计用於槽外或加工模组之用，SD/LD加入一个FRPP射出成型的脚座，脚架及泵到马达的外罩，没有螺栓或金属会接触到所抽送的溶液。

The mean duration of nymphal development is 60 days in constant long phtopheriod(LD 16:8h) at 30℃.But the mean duration of nymphal development is over 120 days in constant short phtopheriod(LD 12:12h) at 30℃.

在30℃连续长日(LD 16：8h)条件下，小悍蟋若虫60日内全部供试个体完成羽化，而在连续短日(LD12：12h)条件下，小悍蟋若虫120日内仍只有90.7%的个体完成羽化。

However in Hachijo population, nymphal development was the fastest under LD 12:12h, followed by LD 14:10h and the slowest under LD 16:8h. Nymphal growth is restrained when the nymphs are transferred from LD 16:8h to LD 12:12h at 60 and 120 days after hatching, rapid development is observed when nymphs were transferred in the opposite direction in Hachijo population.

八丈岛种群的若虫在短日条件下发育最快，其次是中间日长，长日条件下若虫发育最慢，孵化后60d或120d将若虫自LD 16：8h向LD 12：12h转移抑制若虫发育，反方向转移的若虫快速发育。

In the Okinawa population, nymphs developed faster under LD16:8h and LD14:10h than under LD 12:12h at constant photoperiods. When photopersodic shifts from long days (LD16:8h) to short days (LD 12:12h) at 60 and 120 days restrain nymphal development, while photoperiodic shifts from short days to long days accelerate the nymphal development.

冲绳种群在长日条件下(LD 16：8h)若虫发育显著快于中间日长(LD 14：10h)和短日条件下(LD 12：12h)的若虫发育，孵化后60d或120d将若虫自LD16，8h向LD 12：12h转移，若虫发育受到抑制，而自LD 12：12h向LD 16：8h转移，则促进若虫发育。

Based on the laser longitudinal mode splitting theory, a novel scheme of dual-frequency laser with large frequency-difference is presented using electrically controlled birefringence of liquid crystal, and the transmitted resonant mode splitting by birefringent of Fabry-Perot etalon has been analyzed theoretically. A new element of liquid crystal Fabry-Perot etalon is designed and fabricated, which serves as aselector and splitter of both laser longitudinal modes and Fabry-Perot etalons transmitted resonant modes. Two different experimental systems of laser-diode end-pumped Nd:YAG laser have been set up using two different LDs, and the transmission of liquid-crystal cell have been measured. When the empty LCFP is inserted in the cavity of high-power LD pumped Nd:YAG laser, the oscillation of a single laser longitudinal mode have been observed, such a result shows that the designed and fabricated LCFP element is capable of selecting single axial mode. While an anti-reflected liquid crystal cell is inserted in the cavity of Nd:YAG laser end-pumped by the high-power LD, it is difficult to confirm weather the laser longitudinal modes have been spitted or not. The subject is summarized in this thesis and the improvement of the project has been presented.

论文以激光纵模的分裂理论为基础，提出了可望获得几十GHz甚至上百GHz的液晶电控双折射双频Nd：YAG激光器的总体方案，并对用双折射效应分裂F-P标准具透射谐振模进行了理论分析；设计并加工了一种集激光纵模选择、激光纵模分裂和F-P标准具谐振透射模分裂于一体的多功能元件——液晶电控双折射F-P标准具；建立了两种不同功率激光二极管端面泵浦的Nd：YAG激光实验系统，并对液晶盒的透射性质进行了测试；将未灌注液晶的空液晶F-P摘要标准具插入大功率LD泵浦Nd：、叭G激光谐振腔内，观察到了单纵模激光输出，说明所设计和加工的液晶F一P标准具具有纵模选择能力；将镀有增透膜的液晶盒插入大功率LD泵浦Nd八7AG激光谐振腔内，是否产生了激光纵模分裂现象还难以确定。

Methods The PCR enhancers,like dimethyl sulphoxide,glycerol,betaine and betaine of different concentrations were put into the LD-PCR mixture,then the results of amplification were compared.

在LD-PCR反应体系中加入DMSO、甘油及不同浓度的甜菜碱进行LD-PCR扩增，比较扩增结果。

In this thesis, Based on the advantages of diode-pumped solid-state laser in Chapter 1, the development of diode-pumped solid-state laser is introduced. The trends of DPSSL are pointed out, the wide application fields ,as well as the bright market future of high power DPSSL are also summarized. In the Chapter 2 , all kinds of solid-state laser gain materials are introduced in detail. In the Chapter 3 , the theory on the mode-matching of the pump beam and the cavity mode is analyzed in detail based on the basic theory and work principle of LD-pumped all-solid-state laser.

本论文第一章从二极管泵浦固体激光器的优势出发，介绍了二极管泵浦固体激光器的发展，指出了DPSSL的发展方向，概括介绍了大功率DPSSL的诸多应用领域和广阔的市场前景；第二章对固体激光增益材料作了详细的介绍；第三章基于LD泵浦固体激光器的基本理论和工作原理，从理论上详细分析了LD端面泵浦激光器中泵浦光与腔模的匹配问题。

A novel scheme of designing the LD driver based on field programmable gate array is proposed. Employing FPGA as the controlling center, all the functional modules of the LD driver, including AD/DA converting, temperature PID controlling, invariably current driving, LD protection, input and output circuit, are arranged to operate together harmoniously under FPGA.

提出了一种新型的基于现场可编程门阵列技术的半导体激光器驱动电源设计方案，该方案以 FPGA 为控制核心， LD 驱动电源的 AD/DA 转换、温度 PID 控制、恒定电流驱动、LD 保护及人机交互等功能模块电路均在 FPGA 的控制下协调工作。

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。