With the more and more extensive application of power electronics technology , especially with the increasing frequency of main switching device , there have a higher requirement to the power switching diode . the si p - i - n diode have played an important role in these areas so many years 随着电力电子技术应用的深入，尤其是主开关器件工作频率的不断提高，对功率二极管性能提出了更高的要求，多年来硅p - i - n二极管一直在这方面扮演着重要角色。
Millimeter wave system has many distinct advantages such as miniaturizing system components , increasing frequency band width , providing higher detectability , uneasily influenced by atmosphere conditions , etc . this makes millimeter wave technique get the increasingly extensive application in radar , communications , electronic warfare , guidance , remote sensing , radiation survey , therefore the research of millimeter system is very vital for civil , the industry , national defense 毫米波系统具有可以使元部件小型化、增加系统带宽、提供高分辨率以及受大气条件的影响较小等许多明显的优点,这使得毫米波技术在雷达、通信、对抗、制导、遥感和辐射测量等技术领域中得到日益广泛的应用,所以毫米波系统的研究对于民用、工业、国防具有重要的意义。
Based on comparison between the parallel - parallel and parallel - serial combination ttfc , a novel two - transistor forward converter with parallel - serial / serial combination is proposed . this converter reduces greatly the current overshoot of the primary side switches and the voltage overshoot of the rectifying diodes . moreover , the size and weight of the converter can also be reduced by interleaving technique and increasing frequency 本文在对并-串型和并-并型双管正激组合变换器进行了详细比较研究的基础上，提出了一种新型并-串串型双管正激组合变换器，该组合变换器可以大大减小原边开关管的电流应力和副边整流电路中二极管的电压应力；通过交错控制及提高开关频率，大大提高了变换器的功率密度。
The north karst mountain area of guangdong is one of the main impoverished region in guangdong , it ' s natural environment is congenitally fragile , the social and economic sustainable development is restricted by eco - environment problems such as water anti soil erosion , shortage in water resource , increased frequency in natural drought and waterlogging disasters , etc 摘要粤北岩溶山区是广东省主要的贫困地区之一，自然环境先天脆弱，水土流失严重、水资源短缺、早涝灾害频繁等一系列生态问题已成为制约当地社会经济可持续发展的关键因素。
The results showed that the permittivity of matrix glass is very low . when the absorbing coating doped with 5wt % absorber , the permittivity increased rapidly and decreased with the increasing frequency . the reflectivity of the designed absorbing coating of 2 . 2mm thickness was mostly lower than - 10db at x band 基体玻璃介电常数的实部和虚部都比较低；掺杂5wt的纳米吸收剂以后，吸波涂层介电常数的实部和虚部均有大幅度的增加；介电常数随着频率的升高而有一定的下降，具有比较好的频散效应；由所得介电常数设计的2 . 2mm厚吸波涂层在x波段的反射率基本上都小于- 10db 。
If in the long endometriosis , menstrual there will be long , a large quantity of menstrual symptoms , and in serious cases can lead to anemia patients if long in the intramural uterine muscle or subserosal , and highlight the field , while forward oppression bladder , patients nocturia increased frequency of feeling ; backward will be oppression rectum , constipation symptoms appear 如果长在内膜上，会出现经期长、月经量大的症状，严重的可以导致患者出现贫血；如果长在子宫肌壁间或浆膜下，并且向外突出，向前则压迫膀胱，患者有夜尿增多、尿频的感觉；向后则会压迫直肠，出现便秘的症状。
Like the oocytes of aged mice , the reconstituted oocytes by gvs of aged mice and enucleated gv oocytes of young mice showed significantly increased frequency of premature chromatid separation , spindle disruption and / or chromosome misalignment . in contrast , the reconstituted oocytes by gvs of young mice and enucleated gv oocytes of aged mice behaved 由不同校质比gv期卵母细胞成熟后的mll期卵母细胞以及发育成的原核期胚和2一细胞期胚中pkcq的分布并不受细胞质减少的影响。
Abstract : a structure of power automation in beijing airport is introduced , and the function design of every main module is proposed . an idea to develop this system is presented based on the developing platform , some essentials to communicate are explained by means of point - to - multipoint wireless increasing frequency and to synthesize computer voice 文摘:系统介绍了首都机场供电自动化控制系统的结构，概要地说明了系统内各主要模块的功能设计，阐述了基于开发平台研制该系统的思想，具体介绍了点对多点无线扩频通讯以及电脑语音自动合成的部分实现要点。
The mice showed also ageing - associated decline in oocyte quality , as indicated by increased frequency of premature chromatid separation , spindle disruption and / or chromosome misalignments in mii oocytes of aged mice . the gv oocytes from aged mice normally matured in vitro . the percentages of pronuclear - stage embryos , 2 - cell embryos and blastocyst derived from mii oocytes of aged mice by in vitro fertilization ( ivf ) were comparable with ones of young mice , but pronuclei formed 1 h later in aged mice than in young mice 老龄小鼠gv期卵母细胞能正常体外成熟；老龄小鼠m期卵母细胞经体外受精后形成原核期胚、 2 -细胞期胚和囊胚的比率与年轻小鼠比较无显著差异，但原核形成时间延迟1小时；在老龄小鼠卵母细胞，注射牛精子抽提物或sr ~ ( 2 + )处理时所诱发的ca ~ ( 2 + )振荡以及在减数分裂成熟及早期胚胎中的pkc分布未发生改变。
In recent years , factors such as the unsuccessful protection of bcg , increasing frequency of drug - resistance mtb , incidence of hiv - associated tuberculosis and increase mcnt of population movement , have aggravated further ( he opportunity of people worldwide face to the threat of tb 近年来，由于预防疫苗卡介苗( bacilluscalmetteguerin ， bcg )保护性不完善、耐药mtb流行、与人类免疫缺陷病毒( humanimmunodificiciencyvirus ， hiv )的合并感染以及人口流动等原因使tb疫情日益严重。
