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Search Results: 1 - 10 of 67169 matches for " 曹敏? "
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糖耐量减低与动脉粥样硬化相关性的研究进展
The Research Progress about the Correlation of Impaired Glucose Tolerance and Atherosclerosis
 [PDF]

, 中朝
Medical Diagnosis (MD) , 2015, DOI: 10.12677/MD.2015.51001
Abstract:
糖尿病已确定为动脉粥样硬化的危险因素,但糖尿病前期的糖耐量减低阶段是否已经开始了动脉硬化的进程尚无明确定论。我们对国内外关于糖耐量减低与动脉粥样硬化的相关研究做了综述,旨在明确糖代谢异常病人的动脉粥样硬化起始阶段,了解动脉僵硬度的变化,从而给予针对性的早期防治,以阻止和延缓血管硬化病变的发生和发展。
Diabetes has been identified as a risk factor for atherosclerosis, but whether pre-diabetes glucose tolerance has already started the process of atherosclerosis is still not clear. In this paper, the correlation of impaired glucose tolerance and atherosclerosis was reviewed with the aim to un-derstand the initial stage of atherosclerosis and changes of arterial stiffness in glycometabolism abnormalities patients. It will help provide targeted therapy, reduce or delay the occurrence and development of vascular lesions.
渗透胁迫条件下冬小麦幼苗两种内源激素含量的变化

植物学报 , 1990,
Abstract:
风电接入配电网后的继电保护方案研究
Study on Relay Protection Scheme in Wind Power Integration Distribute Network
 [PDF]

, 尹福荣, 夏芸
Journal of Electrical Engineering (JEE) , 2016, DOI: 10.12677/JEE.2016.43022
Abstract:
现有的继电保护系统中一般将风力发电系统作为同步发电机处理,不考虑故障下风电场提供的短路电流对继电保护的影响,但是随着大规模风电接入配电网,风力发电系统对配电网故障点提供的短路电流将会降低继电保护装置的选择性,进而导致继电保护装置的误动。为了保证继电保护满足“四性”的要求,本文通过研究分析风电接入配电网下的故障机理,提出将具有动作速度快、方向性明确、不受过渡阻抗影响的工频故障分量距离保护应用于配网的保护方案中。
Wind power generation system is generally treated as synchronous generators in the relay pro-tection system, and regardless of influence short-circuit current that provided by wind farms. But with large-scale wind power integration distribute network, the selectivity of relay protection devices is reduced by short circuit current provided by wind power generation system, which leads to the maloperation of relay protection device. In order to guarantee the relay protection to meet the requirements of the “four characteristics”, this paper, through research and analysis on wind power distribution network fault mechanism, puts forward that distance protection using power frequency fault components of voltage and current which has action speed, clear direction and not affected by the influence of transition impedance is applied to distribution network protection scheme.
架空线路参数计算方案研究
Research on Calculation Scheme of Overhead Line Parameters
 [PDF]

, 尹福荣, 夏芸
Journal of Electrical Engineering (JEE) , 2016, DOI: 10.12677/JEE.2016.43021
Abstract:
随着继电保护对电网稳定运行的影响越来越大,继电保护定值的准确性也越来越重要,而在继电保护定值的计算过程中架空线路参数是非常重要的基础数据。本文针对传统计算法未考虑各杆塔接线形式导致计算结果不准确的问题,根据某调度继电保护处架空线路参数的计算方案,研究分析了其对各杆塔接线形式的处理以及对各段线路归属的处理,并提出了其存在的问题以及改进的思路。
As the relay protection effect on the stability of power grid is more and more big, the accuracy of the relay protection setting value is becoming more and more important. And in the process of relay protection setting calculation, overhead line parameters are very important basic data. Traditional calculation method, without considering the tower connection form leads to problem of inaccurate calculation results. This paper according to the overhead line parameters calculation schemes provided by a relay protection department, studied each tower connection form of processing and where each line belongs to, and put forward the existing problems and improvement ideas.
基于动态分区的电力系统电磁暂态外部系统等值方法研究
Research on Method of Power System Electromagnetic Transient External System Equivalence Based on Fault Current Distribution
 [PDF]

, 尹福荣, 夏芸
Journal of Electrical Engineering (JEE) , 2016, DOI: 10.12677/JEE.2016.43016
Abstract:
随着电力系统的重要性越来越高,仿真作为预防事故的重要手段也显得尤为必要,为提高仿真效率一般将仿真区域外的系统做一个等值,而目前常见的两种等值方法Ward等值法和网络等值法各有优缺点且无法满足大系统多节点的要求。针对以上问题,本文提出了一种基于动态分区的电力系统电磁暂态仿真外部系统等值方法,用来满足大系统多节点情况下的仿真需求,并提出了存在的问题及未来的发展趋势。
Due to fact that the importance of electric power system is higher and higher, the simulation as an important means of accident prevention is very necessary. In order to improve the simulation efficiency, an equivalent area is generally used for simulation system. Two common equivalent methods, Ward equivalent method and network equivalent method, have its advantages and disadvantages and cannot satisfy the requirement of large system more nodes. This paper, to solve above problems, according to a research unit based on the research and development of dynamic partitioning of power system electromagnetic transient simulation software, studies the use of two kinds of common external system equivalence method and dynamic partitioning method, and puts forward the existing problems and future development trend.
PHOTOSYNTHETIC RESPONSE TO LIGHT IN UNDERSTORY FOR SIX SPECIES YOUNG TREES OF A TROPICAL SEASONAL RAIN FOREST IN XISHUANGBANNA
西双版纳热带季节雨林6种树种幼树在林下的光合作用

郑征,
植物生态学报 , 1998,
Abstract: 本文研究了西双版纳热带季节6种树种幼树在林下的光合作用。6种树种的叶单位重量面积为16.02-28.67m^2.kg^-1、光合作用光补偿点为3.8-6.5μmol.m^-2.s-1、光量子产率为0.018-0.044、最大净光合速率为1.97-4.71μmolCO2.m^-2.s^-1 46.99-92.33μmolCO.kg^-1.s^-1(以单位叶干重表示)、暗呼吸速率为0.15-0.31μ
西双版纳热带季节雨林6种树种幼树在林下的光合作用
郑征,
植物生态学报 植物生态学报 , 1998,
Abstract:
濒危树种望天树大量结实后幼苗的生长和存活
闫兴富,
植物生态学报 植物生态学报 , 2008, DOI: 10.3773/j.issn.1005-264x.2008.01.006
Abstract: ?在云南西双版纳州勐腊自然保护区补蚌村的灰阴河望天树(Shoreawantianshuea)林,选择群落结构均一的100m×200m区域,设置3条垂直于沟谷并沿谷底到坡顶纵向延伸的20m×100m样带(间隔50m),在每一样带内每隔20m设置谷底、低坡、中坡、次坡顶和坡顶5个均匀分布的观测样地,每一样地内设置两个3m×3m的小样方。从2004年12月初到2005年9月底每隔2~3个月重复记录幼苗株高、基径和叶片数,统计幼苗死亡数和被动物捕食数,计算幼苗死亡率、动物捕食率和存活率;同时测定各样地土壤含水量。实验结束收获全部现存幼苗,测定和计算幼苗单株叶面积、比叶面积、总生物量和根冠比等生长参数。结果表明:在干旱季节,从谷底到坡顶,各样地土壤含水量依次降低,而幼苗死亡率则依次增大,这种趋势一直持续到实验结束,此时幼苗在谷底、低坡、中坡、次坡顶和坡顶的死亡率分别为55.0%、54.3%、39.4%、35.9%和26.5%。动物捕食导致望天树幼苗的大量损失,但各样地间差异不显著,幼苗的“丢失”也可能是动物捕食的结果。水分胁迫对幼苗生长的影响在干旱季节更为明显,实验结束时幼苗株高在谷底和低坡较大,而在坡顶和次坡顶较小,其它生长参数也都表现出类似的特点,但在实验结束时这些差异并不显著。该文就各种环境因素对望天树幼苗生长与存活的影响进行了讨论。研究的结果可为探寻望天树的致危原因、有效地保护这一珍稀濒危树种和退化次生林的恢复等提供幼苗生态学方面的理论依据。
采用过程方法实施安全检查工作的探讨

安全与环境工程 , 2010,
Abstract: 将八项质量管理原则之一的过程方法应用于传统安全检查中,通过分析得到安全检查过程的输入、过程实现所需落实的职责和权限以及准则和方法、安全检查过程输出的相关信息,高效地实施安全检查工作,以达到消除隐患及危险有害因素、确保安全生产的目的;采用该方法实施安全检查,在检查的针对性、全面性、整改的彻底性、预防的系统性等方面均较传统的安全检查有所改进,是发现和消除安全隐患的有效方法之一。
结瘤基因调控区中多个活性位点的发现

科学通报 , 1991,
Abstract: 豆科植物的结瘤是共生生物固氮的首要环节。在豌豆根瘤菌中已鉴定出13个结瘤基因,它们的活动促成豌豆根部结瘤。在这些基因中有一个调控基因nodD。在植物分泌的信号分子——类黄酮的存在下,nodD基因的产物NodD蛋白对其它结瘤基因的活动起着重要的调
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