发电机灭磁的氧化锌阀片串并联组合技术

在氧化锌串并组合技术上,合能电气公司采用均能的原则,使用计算机对氧化锌阀片进行优化组合,并且尽量提高移能效率,留有足够的能量裕度,加强对氧化锌阀片的保护和对磁场断路器检测调试,使装置具有灭磁容量大、速度快、动作可靠、寿命长等优点。 目前国内生产的氧化锌单只阀所能承受的极限能量是15KJ～25KJ,而大型发电机励磁绕组中存贮的能量是几百万焦耳。因此必须采用大量的氧化锌阀片进行串并联组合以提供足够的能容。由于氧化锌阀片间存在着固有的离散性,因此保证氧化锌阀片串、并联组合的均衡性,是氧化锌阀片串并联组合技术的关键。     

氧化锌无间隙避雷器承受综合动作负载能力的一种估计方法

本文通过实验和计算,研究氧化锌阀片的发热特性及避雷器的散热特性;用单个阀片进行“综合试验”,以估计氧化锌无间隙避雷器承受综合动作负载的能力。此法为完善避雷器设计提供信息。     

工业废料生产纳米氧化锌技术

1、氧化锌的用途 氧化锌在陶瓷工业中的应用氧化锌是一种重要的陶瓷化工熔剂原料，在建筑陶瓷、墙地砖、釉料、低温瓷釉料和艺术陶瓷釉料中用量较多。氧化锌在釉中有较强的助熔作用，能够降低釉的膨胀系数，提高产品的热稳定性，同时能增加釉面的光泽与白度，提高釉的弹性。在扩大熔融范围的同时能够增加釉色的光彩．     

一种抑制气体绝缘开关装置暂态地电位升高的措施

在分析外壳地电位升高原因的基础上，提出了用电磁暂态程序计算外壳地电位升高的等值计算模型．通过对外壳地电位升高的计算，表明外壳地电位的升高足以危害与气体绝缘开关装置(GIS)相连的外围设备．为了防止外壳地电位升高对GIS的外围连接设备的影响，提出用线路金属氧化物避雷器限制快速暂态过电压的幅值，用氧化锌阀片来改善GIS与外围设备的连接方式以限制外壳地电位升高．计算结果表明，加装金属氧化物避雷器不仅可以抑制快速暂态过电压，而且可以较为有效地抑制外壳地电位升高，且氧化锌阀片的残压越低，其对外壳地电位升高的抑制效果越好．对国内某550kV GIS的外壳地电位升高进行了现场实测，结果表明计算波形与实测波形比较吻合．     

不同稀土氧化物添加对氧化锌压敏电阻瓷性能的影响

分别采用La2O3、Sm2O3、CeO2、Y2O3掺杂改性氧化锌压敏电阻,研究了不同稀土氧化物对氧化锌压敏电阻微观结构和电性能的影响。结果表明,在摩尔比例相同的情况下,并在烧结温度为1160℃左右烧结成瓷,制备的氧化锌压敏电阻陶瓷具有不同的电性能,其中以Y2O3掺杂改性的阀片性能最佳,其电位梯度达到348v/mm,漏电流为2μA,非线性系数为39,能量吸收密度为284J/cm3,性能优于其他稀土氧化物掺杂改性,更优于传统阀片。     

35kV氧化锌避雷器故障的判断与分析

目前,氧化锌避雷器在人们日常生活中得到了广泛运用,但在实际应用过程中,其极易出现各种故障,如阀片受潮、老化等,不但会对变电站平稳运行带来不良影响,还会波及到人们的正常生活。因此,该文以35kV氧化锌避雷器为例,对其常见故障进行阐述,并深入探究故障的判断与分析方法,希望可以为相关工作者的研究提供一些帮助。     

减振器叠加节流阀片的研究

为了探究减振器叠加阀片等效厚度、设计方法及其对减振器特性的影响,对节流阀片在阀口位置的弯曲变形量和叠加阀片等效厚度进行了研究,给出了等效厚度计算公式. 对叠加阀片的应力进行了分析,对阀片应力和厚度之间的关系及叠加阀片最大厚度的设计进行了探讨. 通过实例对叠加阀片进行了设计和验证,并进行了阻力特性试验. 试验表明,叠加阀片厚度设计、等效厚度计算和应力分析方法是准确的和有效的.     

往复式制冷压缩机阀片振动特性测量系统设计

分析了制冷压缩机阀片振动产生的机理.以某型号冰箱压缩机的进气阀片为研究对象,对压缩机阀片振动特性的测量方案进行了研究,建立了冰箱压缩机阀片振动特性测量系统,确定采用声激励方式实现阀片的振动激励,采用激光测振仪测量阀片振动响应,最后对压缩机阀片振动特性进行了初步测量分析.     

低温溶液加工法制备氧化锌薄膜晶体管

为适应柔性有源有矩阵有机发光二极管(AMOLED)等新型显示技术发展的需要,将低温溶液处理的氧化锌作为半导体层、电化学氧化的氧化铝钕作为栅绝缘层,制备了氧化锌薄膜晶体管(TFT).制备氧化锌半导体层所用的前驱体溶液为无碳的Zn(OH)x-(NH3)y(2-x)+水溶液,这种氨络合物溶液制备简单、成本低,并且由于容易形成高活性的氢氧自由基,使得氨-金属之间的分解所需要的活化能较低,生成氧化锌所需的能量较小,可以在180℃的较低温度下获得氧化锌多晶薄膜.所制备的TFT器件的最高迁移率可达0.9 cm2/(V·s).这种低温氧化锌薄膜工艺与室温电化学氧化的栅绝缘层工艺相结合,具有温度低和迁移率高的特点,完全能与柔性衬底兼容,在柔性显示中具有很大的应用前景.     

减振器阀系不等外径多阀片结构变形分析

通过环形弹性复原阀系的力学模型,对减振器复原阀和压缩阀的不等外径多阀片结构弯曲变形进行了分析.利用单环形薄板变形理论推导,单阀片边界条件为内圆固定约束、外圆自由,求得了单阀片变形弯曲系数,给出了任意位置阀片变形的解析计算公式.对不等外径多阀片进行有效变换并利用单阀片叠加原理求得了不等外径多阀片结构变形解析理论公式.最终将解析计算与ANSYS仿真结果进行对比,相互验证了边界条件的处理和等效变换及理论解析计算的正确性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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