查询词典 HF

The strength, acidproof and basicproof stability, conductivity and performance of isolating high-voltage electric field of the joint were investigated in detail.

本文采用激光烧蚀、HF腐蚀和阴离子膜封堵的方法制作了一高压电场隔离接口，并对该接口的强度、耐酸碱稳定性、导电率及隔离电场性能等进行了详细研究，结果表明采用激光烧蚀、HF腐蚀和阴离子膜封堵的方法制作的高压电场隔离接口性能优良，有一定潜在的商业价值，可望推广应用。

Nerve ton e deterioration; vagal ton e withdr awal,sympathetic ton in creasingand C ardiac v agal ton e in creasing and

患者存在自主神经调节异常，SDNN 和HF 明显降低，LF 降低不明显，LF/HF 比值明显增加；替米少坦治疗3 月后迷走神经活性明

These amphibolite samples have very high initial eHf values of+15.2 to +23.3 and the eHf values are tightly correlated with eNd values.

这些斜长角闪岩有异常高的εHf比值(+15.2～+23.3)，且εHf比值与已发表的εNd比值表现出良好的正相关(r~2=0.81)。

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

Based on hf=λL/DV2/2g,formulain the form of hf= K1·F has beenderived for the hydraulic gradient lines of laterals of subirrigation systems. The formula is also applicable to that of a drip irrigation system. Anotherformula,based on Chezy's V=C RS,in the from of Hf=K2IQ2·F2 has been worked out for the laterals of sprinkler systems.

本文运用管道水动力学原理，对喷灌、滴灌、渗灌系统灌水支管的水力坡降线导出表达的理论公式，讨论其调控的可能途径，为试验研究这类系统的规划设计问题从原理上提供一个分析方法。

At present,Wnt10b is found expression in the developing HF epithelium of the vibrissae and body HF,and it is indicated in the initiated of the HF morphogenesis.

近来研究发现Wnt10b在触须和体毛的胚胎发育过程中表达于毛囊上皮细胞中，可启动并促进毛囊的发育。

This implies a major stage of crustal growth in Proterozoic time and remelting of the crustal material in Early Jurassic time;(5) The Oligocene-Miocene adakites contain magmatic zircons that show similar Hf isotope compositions to the Cretaceous-Paleogene Gangdese batholiths, providing a key constraint that allows evaluation of the nature and timing of crustal thickening in southern Tibet owing to the India-Asia collision; and (6) As a whole, the Hf isotope information observed in zircons from the above Transhimalayan rocks demonstrates a temporal variation in εHf values, and thus TDMC ages, that suggests multiple stages of orogenic or crustal formation events.

五、渐新世、中新世的埃达克岩，其岩浆锆石的铪同位素特徵与白垩纪、古第三纪冈底斯岩浆相似，因而为藏南在印亚碰撞以后，地壳增厚的时间与机制提供了关键性的制约；六、综观上述藏南火成岩中的锆石，它们与时变化的铪同位素初始值及其对应的模式年龄记录了拉萨地块多阶段的造山与地壳形成历史。

Solutions with less than 20% HF may not cause symptom s for up to 24 hours.

含有小于20%的HF的溶液不会在24小时内导致出现症状。

This has important implications which must be considered when HF requirements are introduced to a design organization.

这有必须被考虑的重要涵义当HF 要求被介绍给设计组织。

He does not think he has any responsibility for HF either:'No, thank heavens.

他不认为他有对HF 的任一责任或者： ' 没有，感谢天堂。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！