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Search Results: 1 - 10 of 289076 matches for " 李艳青 "
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风电并网变流器系统中非线性和随机噪声扰动的同步控制研究
Synchronous Control on Wind Power Grid Inverter System with Nonlinear and Stochastic Noise Disturbance
 [PDF]

刘江, 张龙, 蒋中川,
Modeling and Simulation (MOS) , 2016, DOI: 10.12677/MOS.2016.54022
Abstract: 非线性电路与系统是非线性科学的一部分,目前以经受到各个领域的关注。本文研究了风力发电并网中带有随机白噪声和非线性扰动的同步控制问题。利用基尔霍夫定律得到了风力发电系统电网侧变流器的数学模型。设计了适当的自适应同步控制器,借助李雅普洛夫稳定性理论,验证了该同步控制器的有效性。进一步消除由于电流并网产生的非线性及随机扰动,使得风力发电机所产生的电流和电网所产生的电流同步。最后通过Matlab中的Simulink进行了仿真设计研究,验证了该理论结果的有效性。
Nonlinear circuits and systems are parts of nonlinear science, which have been central issues in various kinds of research fields. In this paper, we studied the synchronization control of wind power with disturbance of nonlinearity and white noise. By using the Kirchhoff’s law, we obtained the mathematical model of wind power grid side converter system. Meanwhile, an appropriate adaptive synchronization controller was designed. By establishing a suitable Lyapunov function, we validated the effectiveness of synchronous controller. Therefore, we can eliminate the disturbance of nonlinearity and white noise produced by the wind current embedding into the grid. As a result, we can make the current generated by the wind generator synchronize the current in the grid. Finally through Simulink in Matlab simulation, we validated our theoretical results.
因子分析和数量分类在油菜种质资源遗传多样性研究中的应用
Factor Analysis and Numerical Taxonomy Applied in the Research of Germpasm Genetic Polymorphism in Brassica napus L.
 [PDF]

王道杰, 杨翠玲, , 王再
Botanical Research (BR) , 2014, DOI: 10.12677/BR.2014.36027
Abstract:
应用计算机系统对87份油菜种质资源的14个性状进行了因子和聚类分析。结果表明,14个性状的变异系数值从6.02% (含油量)到96.87%(硫苷)含量,变异范围较大,表明供试材料的遗传多样性是显著的。通过相关分析表明,主花絮有效角果数是1个比较重要的性状,它与多数产量构成因子呈显著或极显著正相关,与株高、一次有效分枝部位、主花序有效长度等株型性状呈极显著正相关。采用主成分分析将14个性状归纳为6个主成分,它们占总遗传变量的80.43%。将87份材料的14个性状值标准化处理后进行聚类分析,结果将87份油菜种质资源分为5个类群,而根据4个品质性状指标进行聚类,将87份油菜种质资源分为6个类群。
Using computer systems, the factor and cluster analysis was done to 14 quality traits of 87 rapeseed germplasm resources. The results showed that the coefficient of variability of 14 agronomic traits ranged greatly from 6.02% (oil content) to 96.87% (glucosinolate content), which indicated the diversity of materials was significant. The correlation analysis shows that the effective silique of main inflorescence is an important trait. It is in significant or highly significant positive correlation with most factors of yield components, and it is in significant positive correlation with plant height, an effective branch height, effective length of main inflorescence and other plant traits. Adopting the principal component analysis, 14 traits were divided into 6 principal components, which accounted for 80.43% of total genetic variations. After 14 quality traits of 87 materials have been standardized, through cluster analysis, all materials were classified into 5 groups, but 6 groups according to 4 quality traits.
高压力容器开口泄爆过程中压力发展特征的实验研究
Experimental Study on Pressure Characteristics of Development in High Pressure Vessel Explosion Venting
 [PDF]

赵振东, , 侯华, 陈超, 郄超阳
International Journal of Mechanics Research (IJM) , 2015, DOI: 10.12677/IJM.2015.41001
Abstract:
建筑物承受高压容器爆炸荷载作用的泄爆设计被日益重视。本文开展了在容积为0.15 m3方形容器中泄爆实验测试。实验装置一端连接高压管道,模拟产生高压爆炸。另一端连接泄爆装置,对不同压力作用的泄爆装置开启过程进行了实验研究。实验结果给出了不同爆炸压力条件下容器内压力发展时程和泄爆装置开启压力、开启时间等指标,对于高压容器的泄爆防护具有工程应用价值。
The design of vented explosion has attracted more concerns for industrial buildings subject to ex-plosive loading of high pressure vessel. The present paper performs the experimental testing re-search of vented explosion within 0.15 m3 rectangular enclosure. High pressure pipeline, using to simulate the explosive behavior, and explosive venting device are respectively connected to both sides of experimental system. The opening process of venting device is studied within different pressure loadings. The major parameters of initial opening pressure and opening period are in-vestigated with the variations of pressures. The experimental results show the practical values in the design for the protection of explosive venting of high pressure vessel.
中国马鞭草属的新记录——长苞马鞭草
,,陈辰
植物学报 , 2005,
Abstract: ?长苞马鞭草(VerbenabracteataCav.exLag.&J.D.Rodriguez)原产北美。2001年春天我们首次在中国大连的马兰水库发现该种植物,它丛生或与其他植物混生,形态与原产地的种一样;因为其苞片通常大、显著且比花萼明显的长,易和原产中国的唯一马鞭草属的V.officinalisL.区分开。
我国城市不同功能区地表灰尘重金属分布及来源
晓燕,
环境科学 , 2013,
Abstract: 为揭示城市不同功能区地表灰尘重金属的分布规律及污染来源,在文献调研的基础上,通过对多个省会城市主要功能区地表灰尘重金属数据的分析和比对,阐述了我国城市不同功能区地表灰尘中Cd、Cu、Pb和Zn的分布及累积差异,并探讨了不同功能区地表灰尘重金属的可能来源及影响因素.结果表明,工业区地表灰尘重金属含量最高,交通区地表灰尘重金属含量最低,商业区和居民文教区地表灰尘重金属含量处于中等水平.4种功能区之间地表灰尘重金属水平分异较大的元素是Zn和Pb,Cu和Cd在不同功能区地表灰尘中的含量差异较小.相对于城市土壤,工业区地表灰尘重金属累积最重,其它3个功能区地表灰尘重金属累积差异不明显,但相对而言,交通区地表灰尘重金属累积最轻.不同功能区地表灰尘累积程度差异最小的元素是Cd.
中国东南部地幔深处的洋壳再循环:来自浙江新生代玄武岩的证据
,马昌前
地质学报 , 2013,
Abstract:
图书馆知识转移效果差距成因分析与对策研究
,景峰
图书情报工作 , 2009,
Abstract: ?以山西省图书馆为例,通过读者、馆员满意度调查对图书馆知识转移效果进行评价,以知识资源、知识提供者、知识转移通道及知识接受者等影响要素为切入点,分析知识转移模式中现实转移与成功转移之间差距的成因,并提出对策。
正交设计在黄金鱼花组织培养中的应用
,,英慧,王火旭
园艺学报 , 2001,
Abstract: 用正交设计法研究了4种激素对黄金鱼花叶片诱导愈伤组织的影响。结果显示,诱导黄金鱼花愈伤组织产生的最佳激素配比为:ms+2,4-d1mg/l+6-ba1mg/l+naa1mg/l,有2,4-d的培养基中愈伤组织诱导率明显高于没有2,4-d的培养基,iba对愈伤组织的诱导有抑制作用。
白细胞介素-21和核因子κB受体活化因子配体在人根尖囊肿和肉芽肿中的表达及临床意义
胡菊花,,,
华西口腔医学杂志 , 2015, DOI: 10.7518/hxkq.2015.03.006
Abstract: 目的检测白细胞介素-21(IL-21)和破骨细胞核因子κB受体活化因子配体(RANKL)在根尖囊肿和根尖肉芽肿中的表达,分析两者在根尖周病中的关系,探讨IL-21在根尖周炎发病机制中的作用。方法收集根尖囊肿23例和根尖肉芽肿32例作为实验组,记录相关病例的病损大小及有无叩痛表现;10例健康牙龈组织为对照组。利用免疫组织化学法检测所有样本中IL-21和RANKL蛋白的表达水平,分析IL-21的表达水平与RANKL表达、根尖病灶大小及叩痛的相关性。结果所有病变组织均可检测到IL-21阳性细胞,而健康牙龈组织则未检测到IL-21的表达。根尖囊肿和肉芽肿中IL-21的表达强度分别为59.92±6.57和36.80±6.81,RANKL的表达强度分别为68.81±18.59和36.12±14.87。根尖囊肿组两种蛋白的表达水平均高于肉芽肿组(P<0.05)。相关性分析表明,IL-21的表达水平与RANKL及根尖病灶大小均呈正相关关系(P<0.05)。结论IL-21存在于人慢性根尖周炎病损组织中,其表达水平与RANKL的表达量及病损大小呈正相关关系;IL-21可能通过促进RANKL蛋白的表达参与慢性根尖周炎的发病机制。
3,4-二氨基苯甲酸缩取代水杨醛Schiff碱及配合物的合成与表征

,冯高潮,,陆兰
 
, 冯高潮,  耿 , 陆兰

- , 2016,
Abstract: 分别以2,4-二羟基苯甲醛、2-羟基-3-甲氧基苯甲醛、5-溴水杨醛为原料,甲醇为溶剂,在适当的温度下分别与3,4-二氨基苯甲酸反应,通过缩合制得3种3,4-二氨基苯甲酸缩取代水杨醛Schiff碱配体,然后由Schiff碱配体分别与Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)的乙酸盐反应制得相应的金属配合物.用元素分析、紫外光谱、红外光谱和核磁共振氢谱等对配体及配合物的结构进行了分析和表征.
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