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油老化状态对油纸绝缘直流电场下空间电荷特性的影响

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中国电机工程学报 2013年第22期33卷 175-182,26页

作者：王妲王世强田杰穆海宝张冠军电力设备电气绝缘国家重点实验室(西安交通大学) 陕西省西安市710049 深圳供电局有限公司广东省深圳市518000

为了深入研究油老化对油纸绝缘直流电场下空间电荷特性的影响,通过加速热老化得到三组不同老化程度的绝缘油试样,并对其进行理化及电气特性分析;然后利用所得油样分别对经过真空干燥的新绝缘纸进行真空浸渍,得到3组油老化状态不同的油... 详细信息

为了深入研究油老化对油纸绝缘直流电场下空间电荷特性的影响,通过加速热老化得到三组不同老化程度的绝缘油试样,并对其进行理化及电气特性分析;然后利用所得油样分别对经过真空干燥的新绝缘纸进行真空浸渍,得到3组油老化状态不同的油纸绝缘试品;进而采用电声脉冲法(pulsed electro-acoustic,PEA)在室温下分别测量了3组试品在施加直流电压和撤除电压情况下的空间电荷分布,讨论了油老化状态对油纸绝缘试品中空间电荷注入、积聚及消散等特性的影响。实验结果表明:施加直流电压下,3组油浸纸试品与电极界面处均发生了同极性电荷注入现象,油老化程度越严重,电极与介质界面处感应的电荷密度峰值越大,积聚在试品中的空间电荷总量也逐渐增大,负电荷积聚区域逐渐向阳极方向推进。撤除电压后,随着绝缘油老化程度的加重,试品中的空间电荷消散速率增大,且正电荷的消散速率大于负电荷的消散速率。

关键词：油纸绝缘油老化电声脉冲法空间电荷

转售价格维持与批发价格决策的组合效应——基于空间价格歧视模型的研究

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经济学（季刊） 2021年第1期20卷 361-382页

作者：叶光亮王世强海南大学中国人民大学中国社会科学院经济研究所北京市西城区100836

本文基于空间价格歧视模型,研究转售价格维持(RPM)和批发价格纵向组合的利润与福利效应。研究表明,上游企业采取纵向价格组合,总能获得更高利润,并提高社会福利;下游市场竞争程度较低时,实施这一组合甚至提高消费者剩余。比较RPM下限与... 详细信息

本文基于空间价格歧视模型,研究转售价格维持(RPM)和批发价格纵向组合的利润与福利效应。研究表明,上游企业采取纵向价格组合,总能获得更高利润,并提高社会福利;下游市场竞争程度较低时,实施这一组合甚至提高消费者剩余。比较RPM下限与上限发现,RPM下限不仅对应更大上游企业利润,在下游市场竞争程度较低时还对应更大社会总福利与消费者剩余。本文建议二者都应适用合理推定原则,反垄断执法机构需要加强对RPM竞争效应的评估和分析。

关键词： RPM 批发价格空间价格歧视

基于凸包的非合作目标视觉导航系统特征点选择方法

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红外与激光工程 2019年第3期48卷 214-222页

作者：宁明峰张世杰王诗强哈尔滨工业大学卫星技术研究所黑龙江哈尔滨150080

非合作目标在接近的过程中,将所提取的特征点直接用于相对导航会因特征点数目过多导致计算量大。为减小相对导航的计算量,需从提取的特征点中选择一个子集用于相对导航。假设所提取的特征点在非合作目标的同平面内,将目标表面特征点选... 详细信息

非合作目标在接近的过程中,将所提取的特征点直接用于相对导航会因特征点数目过多导致计算量大。为减小相对导航的计算量,需从提取的特征点中选择一个子集用于相对导航。假设所提取的特征点在非合作目标的同平面内,将目标表面特征点选择问题转化为像平面特征点选择。同时,文中研究了视觉系统的精度因子(DOP),并利用精度因子与平面特征点构成的面积呈反比的特性,提出像平面特征点的凸包作为观测量用于相对导航。仿真表明:将同平面特征点的凸包用于相对导航,具有较高的精度,同时能够有效减少特征点数;计算凸包的时间远小于求解最优PDOP的时间,能够应用于实时计算。

关键词：非合作目标特征点选择凸包精度因子

民间大地上的行走与歌哭——论赵德发和他的“农民三部曲”

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南方文坛 2007年第1期 66-71页

作者：王士强张清华首都师范大学文学院北京师范大学文学院

批评界对关于“民间”的话题谈论得已经够多了。但许多问题仍然晦暗不明。比如关于乡村民间社会与当代中国主流历史之间的互动演变关系，以及当代农人在这一关系下的意识形态、心灵世界的演变种种，就没有多少作家去予以认真的关注与历... 详细信息

批评界对关于“民间”的话题谈论得已经够多了。但许多问题仍然晦暗不明。比如关于乡村民间社会与当代中国主流历史之间的互动演变关系，以及当代农人在这一关系下的意识形态、心灵世界的演变种种，就没有多少作家去予以认真的关注与历史的清理挖掘。或许当代历史的许多“事件”，比如运动、饥饿、血腥等等标志和表象性的内容，已经被书写得太多，但在这一切重大事件背后的普通人的命运，以及他们究竟经历了怎样的心灵历程，甚至这个被压抑在历史的边缘角落里的“民间意识形态”。究竟是由哪些因素构成等等，仍然没有人去勘和深入地予以关注和挖掘。

关键词：民间社会三部曲赵德发民间意识形态当代历史农民大地重大事件

Solid–liquid Phase Equilibrium in the Ternary System MgCl2-MgB4O7-H2O at 308.15 K

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Solid–liquid Phase Equilibrium in the Ternary System MgCl2-...

中国化学会第六届全国热分析动力学与热动力学学术会议

作者： Yun Song Xuemin Du Dong Zhao shiqiang wang Yafei Guo Tianlong Deng College of Chemical Engineering and Material Science Tianjin University of Science &Technology College of Marine and Environmental Science in TUST Tianjin Key Laboratory of Marine Resources and Chemistry

It is famous that the salt lakes are rich in magnesium boron in the Qinghai-Tibet plateau. The composition of many sulfate brine can be approximated as the complex system of Li, K, Mg//Cl, SO, borate-HO. Meanwhile, salt lake research has a guiding role in the separation and extraction of boron and magnesium in *** equilibrium of the ternary system MgCl-MgBO-HO at 308.15 K has been researched with the isothermal dissolution equilibrium method. The solubilities and physicochemical properties of the system including density, refractive index, viscosity and pH value were analyzed. Based on the experimental data, phase diagram at 308.15 K and physicochemical properties versus compositions diagrams were plotted respectively. The results show that this system belongs to the hydrate type I, and no complex salt and solid solution generates. There is one invariant point(MgCl·6HO + MgBO·7.5 HO) which liquid compositions are MgCl40.04%, MgBO1.34% in mass fraction, two univariant solubility curves of AE and BE, and two crystallization fields which correspond to MgCl·6HO and magnesium borate, respectively. The solubility of the magnesium borate increases with the increasing of MgCl in the equilibrium liquid phase, which indicates that MgCl has the salting-in effect on magnesium borate. Meanwhile it has been found that the MgBO·9HO is not stable, and is easily converted into the MgBO·15HO and MgBO·7.5 *** with the increasing of MgCl, the conversion of MgBO·9HO to MgBO·15HO is *** the inversion point G which liquid compositions are MgCl 30.20%, MgBO 1.32% in mass fraction.

关键词： Phase equilibrium Isothermal dissolution Physico-chemical properties

Solid–liquid Phase Equilibrium in the Quaternary System(Li+,Mg2+//Cl-,B6O114--H2O) at 308.15 K

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Solid–liquid Phase Equilibrium in the Quaternary System(Li+...

中国化学会第十九届全国化学热力学和热分析学术会议

作者： Yun Song Xuemin Du Dong Zhao shiqiang wang Yafei Guo Tianlong Deng Tianjin Key Laboratory of Marine Resources and Chemistry China College of Chemical Engineering and Material ScienceTianjin University of Science & Technology College of Marine and Environmental Science in TUST

As is known that large quantity of lithium,potassium,magnesium,boron brine resources exist in the west of China,especially in Tibet Plateau and Qaidam *** salt lakes mainly are the complicated system Li,Na,K,Mg//Cl,SO,*** composition of brine becomes quinary system Li,Mg//Cl,SO+4,BO-HO after extracting potassium and *** lithium,magnesium,boron resource are still wasted even discharged back into salt lakes because of limited development technology and unstable product *** solubilities and relevant physicochemical properties including density,refractive index and pH values of the aqueous quaternary system(Li,Mg//Cl,BO-HO) at 308.15 K were determined for the first time with the method of isothermal *** to the experimental results,the dry-salt phase diagram and physicochemical properties versus composition diagrams were *** the stable phase diagram,there are three co-saturated invariant points,seven univariant solubility isotherm curves,and five crystallization regions,which correspond to lithium chloride monohydrate(LiCl·HO),lithium tetraborate(LiBO·3HO),inderite(MgBO·15HO),bischofite(MgCl·6HO) and lithium carnallite(LiCl·MgCl·7 HO).MgCl in the solution can retard the conversion of *** also indicates that the physicochemical properties of the stable equilibrium solution are in regular changes with the concentration of Mg along the univariant solubility isotherm curves.

关键词： Phase equilibrium Iso-thermal dissolution Magnesium Borate

A low-molecular-weight polysaccharide from Cremastra appendiculata:extraction,structural characterization and anti-HCC activity

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A low-molecular-weight polysaccharide from Cremastra appendi...

陕西省植物学会2024年学术研讨会

作者： Haoyue Kong Wenna Li Yufei wang Keyan Zhang Yuwen wang Guanghui Jiang shiqiang wang Zhezhi wang Junfeng Niu National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China The Key Laboratory of Medicinal Resources and Natural Pharmaceutical ChemistryThe Ministry of EducationCollege of Life SciencesShaanxi Normal University

The medicinal benefits of Cremastra appendiculata include fever reduction,detoxification,the elimination of phlegm and masses,and its extensive use for the treatment of various ***,the kinetics behind the anti-tumor effects of *** polysaccharide(CAP)(one of the primary substances of its water-soluble components) remain *** this study,CAP was prepared and characterized,and its anti-hepatocellular carcinoma(HCC) activities were *** analysis revealed that CAP(Mw=8,058 Da) was a linear glucomannan composed of → 4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 →.In an anti-HCC trial,CAP mediated macrophages significantly inhibited the migration and proliferation of Hepa1-6 ***,CAP inhibited the growth of tumors in mice,and at high-doses,resisted the immune organ damage induced by 5-fluorouracil(5-Fu).Moreover,CAP enhanced the immune organ index of mice,increased the levels of serum cytokines(TNF-α and IFN-γ),and improved their immune functions,thereby indirectly eliminating *** study provides theoretical and experimental support for the use of CAP in the treatment of hepatocellular carcinoma and promotes the development of natural polysaccharides from traditional medicines.

关键词： Polysaccharide Structural characterization CM Antitumor activities

Volumetric properties of aqueous solution of lithium tetraboratefrom 283.15 to 363.15 K at 101.25 KPa

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Volumetric properties of aqueous solution of lithium tetrabo...

中国化学会第六届全国热分析动力学与热动力学学术会议

作者： Yafei Guo Kaiyu Zhao Long Li Lingzong Meng shiqiang wang Tianlong Deng Tianjin Key Laboratory of Marine Resources and Chemistry College of Chemical Engineering and Materials Science Tianjin University of Science and Technology College of Chemistry and materials Science Northwest University School of Chemistry and Chemical Engineering Linyi University

Densities of aqueous solutions of lithium tetraboratein the(0.01 to 0.12)mol·kg concentration range at a 5 K intervals from 283.15 to 363.15 K at 101.25 KPawere measured using a precise Anton Paar Digital vibrating-tube densimeter. Apparent molar volumes are obtainedon the basis of experimental density data, and then the 3 D diagram of(m, T,V) versus different concentration and temperature were plotted in Fig. 1. On the basis of Pitzer ion-interaction equation of the apparent molar volume model, the Pitzer single-salt parameters(?(0)v),?(1)v),?(2)v) and C),and their temperature-dependence correlation F(i,p,T) = a + aT + aT + a/T + a5ln(T) +a/(T-263) + a/(680-T)(where Tis temperature in Kelvin, pis a pressure in 101.25 KPa,a are model parameters) for LiBO are obtained, which is not reported in the *** deviations of the experimental and calculated values of Pitzer single-salt parameters ?(0)v),?(1)v),?(2)v) and Cfor LiBO are all within±0.1,and those results indicate that the singlesaltparameters and theirrelational coefficients oftemperature-dependencefor LiBO obtained in this work are reliable.

关键词： Lithium tetraborate Apparent molar volume Pitzer model

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2种地方酒曲主要微生物特性的比较研究

中国酿造 2010年第3期29卷 141-142页

作者：王世强郑扬云黄山学院生命与环境科学学院安徽黄山245041

对苏州酒曲与徽州酒曲主要微生物——酵母菌和霉菌的菌落及个体形态﹑生长状况、淀粉酶活力及酒化力等方面进行了比较研究。结果表明,两者除酵母菌形态方面差异不明显外,徽州酒曲酵母菌的出芽率、根霉的产孢能力、淀粉酶活力、酒化力均... 详细信息

对苏州酒曲与徽州酒曲主要微生物——酵母菌和霉菌的菌落及个体形态﹑生长状况、淀粉酶活力及酒化力等方面进行了比较研究。结果表明,两者除酵母菌形态方面差异不明显外,徽州酒曲酵母菌的出芽率、根霉的产孢能力、淀粉酶活力、酒化力均高于苏州酒曲。

关键词：苏州酒曲徽州酒曲酿酒