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s仿紧空间的开fσ遗传性  [PDF]
葛洵
南京邮电大学学报(自然科学版) , 2008,
Abstract: 讨论了s仿紧空间的开fσ遗传性,证明了正规s仿紧空间的开fσ子空间是s仿紧的。这一结果深化了k.y.alzoubi关于s仿紧空间的开闭遗传性。
关阀过程中管内瞬变流一二维数值模拟对比  [PDF]
郭艳惠,刘德有,周领
人民黄河 , 2013,
Abstract: ?应用动网格技术对输水管内不同关阀速度时的瞬变流进行了二维数值模拟,并将其计算结果与经典一维特征线法计算结果进行了对比,探讨了关阀速度、进口压力水头、管径三个主要因素取值不同对两种方法计算结果相对偏差值的影响.算例结果表明:两种方法计算结果在阀前管段的最大偏差值约10%,而阀后管段的最大偏差值可能接近100%;与阀门距离越远该偏差值越小,这种衰减趋势在5倍管径距离范围内尤为明显,但对于阀后管段,即使在与阀门10倍管径距离处,该偏差值仍可能为10%以上;关阀速度或进口压力水头越大,该相对偏差值越大;而管径越大,该相对偏差值越小.
液氧输送管路中阀控瞬变的数值计算  [PDF]
陈勇,李隆键,程静
哈尔滨工业大学学报 , 2013, DOI: 10.11918/j.issn.0367-6234.2013.09.014
Abstract: 为了预测航天器液氧输送系统中阀控动作产生的水力瞬变,考虑非稳态摩阻和波纹管弹性形变的影响,建立输送硬管、波纹软管、液氧贮罐及控制阀的数学模型,并利用求解一阶偏微分方程的特征线法和求解一元二次非线性方程的线性理论法对管路阀控瞬变进行数值计算.通过变化计算条件,讨论不同阀特性、阀动作指数和动作时间对瞬变过程的影响.计算结果表明:采用调节阀进行阀控动作产生的压力波动明显比截止阀小,调节阀比截止阀更容易控制液氧输送总量精度;延长调节阀关阀时间能够有效降低水击压力,延长截止阀关阀时间更多地表现为延长第一个水击波到达的时间,而不是水击压力的降低;阀动作指数m=1.0的调节阀采用快开慢关方案对瞬变过程控制最有利.
基于铜离子修饰金纳米簇“关-开”型荧光探针检测多巴胺  [PDF]
于锡娟,韩璐璐,混旭
- , 2017,
Abstract: 摘要 以11-巯基十一烷酸(11-MUA)为还原剂和保护剂,通过一步水热法合成了具有强烈荧光的水溶性金纳米簇(AuNCs),基于Cu2+修饰的AuNCs@11-MUA构建了"关-开"型荧光探针用于多巴胺(DA)的选择性、高灵敏检测.向AuNCs@11-MUA溶液中加入Cu2+离子后,AuNCs@11-MUA的荧光发生猝灭,体系的荧光信号处于"关闭"状态.在DA存在下,由于DA与Cu2+具有更强的结合力,形成比Cu2+/AuNCs@11-MUA复合体更稳定的络合物,可将Cu2+从AuNCs@11-MUA表面移除下来,从而使其荧光得以恢复,体系的荧光信号呈"打开"状态.AuNCs@11-MUA探针的荧光恢复程度与DA的浓度在2.0×10-7~5.0×10-5 mol/L范围呈良好的线性关系,检出限为8.0×10-8 mol/L(S/N=3).将该探针应用于人血清和尿液中DA的检测,回收率为93.2%~97.3%,相对标准偏差RSD<4.08%,表明该方法可应用于人体内多巴胺的检测
共轭聚合物荧光“开-关”的构建及对S-腺苷甲硫氨酸的分子识别与检测  [PDF]
李慧芝,翟涛,张广友,裴梅山
分析化学 , 2014, DOI: 10.11895/j.issn.0253-3820.140073
Abstract: 以Pb2+和S-腺苷甲硫氨酸(S-Adenosylmethionine,SAM)与聚3-(1-(2-三乙胺乙酰基)哌啶-4-亚甲基)噻吩(poly3-{[1-(2-hydrazino-2-oxoethyl)piperidin-4-ylidene]methyl}thiophene,PMTH)构建荧光开关,当有Pb2+存在时,PMTH与Pb2+之间发生作用,荧光猝灭,即为荧光“关”;当Pb2+-PMTH体系中加入SAM时,SAM能够与Pb2+形成更稳定的配合物,使PMTH的荧光恢复,即为荧光“开”。通过PMTH的荧光开关信号,成功建立了识别和检测SAM的新方法。研究了在水-乙醇(4:1,V/V)溶液中Pb2+和PMTH与SAM相互作用对荧光光谱的影响。本方法具有很好的灵敏度和选择性,常见氨基酸和金属离子对SAM的检测无影响,在最佳实验条件下,SAM的浓度在1.0×10-8~2.0×10-6mol/L范围内与相对荧光强度呈线性相关,线性回归方程为ΔI=68.51+72.32C(μmol/L),相关系数r=0.9982,检出限为8.72×10-9mol/L;本方法已成功用于SAM检测。
A Novel Low Power Loss IGBT (LPL-IGBT) and Its Simulation
低功耗IGBT(LPL-IGBT)及其仿真

WU Yu,LU Xiu hong,KANG Bao wei,WANG Zhe,CHENG Xu,GAO Yan,
吴郁
,陆秀洪,亢宝位,王哲,程序,高琰

半导体学报 , 2001,
Abstract: A new structure IGBT,named Low Power Loss IGBT (LPL IGBT) is proposed.It keeps the advantages of NPT IGBTs because of its very thin and lightly doped p type back emitter formed using ion implantation.Meanwhile,it also takes the advantages of PT IGBTs due to its n type buffer layer which is the residual layer of the pre diffused n + region at the backside of the n - substrate.Simulation results show that its turn off power loss is almost a half of that of the PT IGBT or NPT IGBT.Furthermore,its structure is more suitable for practical production than FSIGBT.
仿紧空间的滤子性质  [PDF]
蒋继光
科学通报 , 1991,
Abstract: 新近,文献[1]给出次亚紧性与次仿紧性的下列滤子性质(A)ω上有滤子具有性质对每个次亚紧空间X,X的每个开覆盖有一列开加细使得x∈X,{n<ωord(x,)<ω}∈。(B)ω上有滤子具有性质对每个次仿紧空间X,x的每个开覆盖有加细
Optimalization of IGBT Communication
Pavol Spanik,Ivan Feno,Radovan Ovcarcik
Advances in Electrical and Electronic Engineering , 2002,
Abstract: The paper presents IGBT switch off process in order to reduce power loss in the structure. The soft switching method using switch-off after current reduction is used. Process mentioned above is optimized to minimize the power loss that is determined by experiment. Results obtained in the experiment can be helpful in a converter and controller design process.
IGBT电压击穿特性分析  [PDF]
汪波,胡安,唐勇,陈明
电工技术学报 , 2011,
Abstract: 针对绝缘栅双极晶体管(IGBT)应用选型中长期以来采用经验的粗放式设计方法,本文基于IGBT结构和PN结雪崩击穿原理,分析了场终止型IGBT雪崩击穿电压的计算公式和测量方法。由于线路和器件内部分布电感的存在,开关时会产生一个电压尖峰,分析了IGBT过电压击穿特性和电压尖峰的抑制方法。针对通常认为一旦发生过电压击穿就会损坏器件的错误认识,分析了IGBT过电压击穿失效机理和失效模式,发现过电压击穿失效本质是由于热量累积引起结温上升的热击穿失效,失效模式初始表现为短路最终表现为开路,最后实验验证了IGBT具有可承受短时过电压击穿的能力。
SPT+-IGBT characteristics and optimization
SPT -IGBT的性能研究及优化

Chu Weili,Zhu Yangjun,Zhang Jie,Hu Aibin,
Chu Weili
,Zhu Yangjun,Zhang Jie,Hu Aibin

半导体学报 , 2013,
Abstract: A novel advanced soft punch through (SPT) IGBT signed as SPT+-IGBT is investigated. Static and dynamic characteristics are simulated based on the 1200 V device structure and adopted technology. Extensive research on the structure optimization of SPT+-IGBT is presented and discussed. Compared with the structure of conventional IGBT, SPT+-IGBT has a much lower collector-emitter saturation voltage and better switching characteristics. Therefore it is very suitable for applications blocking a voltage higher than 3000 V. In addition, due to the improvement of switching speed achieved by using a thinner chip, SPT+-IGBT is also very competitive in 1200 V and 1700 V applications.
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