ITER极向场线圈销轴表面硬化工艺研发

ITER极向场线圈(PF)磁体支撑销轴承载极向场线圈和部分真空室的质量,因使用环境非常恶劣,所以对其表面硬度及耐磨性能有很高的需求。按照ITER极向场线圈销轴的设计要求,研发了两种表面硬化处理方式,包括无界面N离子注入361LN强化处理以及采用在不锈钢表面堆焊一层马氏体不锈钢ER414L的方式分别不同程度地增加基底材料的表面硬度以及耐磨性能,可以满足小尺寸及超大型部件的表面硬化设计需求。     

利润-CVaR准则下的二级供应链定价与订货策略研究

传统的定价与订货策略研究多是建立在风险中性的假设之上,近来也有利用风险度量CVaR研究风险厌恶对库存的影响.因此,以期望利润和CVaR的加权平均为目标函数,研究零售商的订货策略,并在此基础上研究上游供应商的定价策略.这样的利润-CVaR目标既反映了决策者追求高利润的愿望,又反映了其对潜在风险的控制.     

电信计费分析数据仓库系统的设计与实现

该文主要研究如何用数据仓库及其技术解决电信计费分析的实际问题。     

探讨数据库加密技术

从数据库安全需求着手,提出数据库加密要实现的目标,分析了数据库加密技术中几项关键技术并进行比较,最后对加密后系统产生的影响进行总结。     

门在我国家具造型中的应用及发展

我国传统家具之所以能够成为一个世界优秀的种类,与外来文化的吸收融合密不可分。在历史上佛教曾对我国家具产生过巨大的影响。本文从"门"这个独特的角度研究我国传统家具在结构、式样上的发展演变过程。     

略论盐城“水利梦”

认真学习领会习近平总书记提出的"中国梦",结合实际,论述了如何转化为干好盐城水利工作的动力,见诸行动,出实策、鼓实劲、办实事,力争实现盐城的"水安全梦"、"水资源梦"、"水环境梦"、"水生态梦"、"水经济梦"和"水文化梦",同心践行和助力"中国梦",真正实现人水相依、和谐共生、良性循环、全面繁荣。     

两种水轮发电机组开机控制技术的比较及优化

本文建立了水轮发电机组仿真模型,并以某电站的水流特性、机组惯性等实际参数作为仿真模型参数,着重研究水轮发电机组的两种开机控制规律,分析了原有以空载开度为限制的机组开机控制技术,提出以恒转速变化率为控制目标的机组开机控制技术,并将两种开机控制技术进行了仿真比较。通过仿真波形分析比较表明,两种开机控制技术各自具有的优越动态性能。在工程实践中,将这两种开机控制技术都应用到水轮机调速器开机程序中,可以根据水电站现场对开机动态性能的不同要求在停机态切换两种开机控制流程。     

Study of partial discharge characteristics at repetitive square voltages based on UHF method

Due to overvoltage produced by inverter output,inverter-fed motor insulation systems often experience fast electrical aging process,especially when partial discharge(PD) is incepted.Before putting into use,the PD detection should be performed on inverter-fed motors at repetitive square voltages to avoid the PD caused insulation deterioration when the motors are collected to inverters having specific characteristics.However,unlike PD tests at AC/DC voltages proposed in IEC 60270,the PD detection at repetitive square voltages is much more complex because of serious interference generated by impulse generator.To solve the problem,ultra-high frequency(UHF) method seems recommendable for its preferable signal-to-noise ratio(SNR).The chief aim of this study is to investigate PD pulse and statistical characteristics of turn-to-turn insulation for inverter-fed traction motors.A square-shaped Archimedes antenna,specially designed for the PD detection at repetitive square voltages of fast rise times,was used to perform PD tests on turn-to-turn insulation models.Time and frequency analysis results indicate that energy component of generator disturbance and PD pulses are mainly distributed in the 0-0.5 GHz and 0.6-1.5 GHz range,respectively.Based on the results,suitable filter was designed for power disturbance suppression.Additionally,resorting to the sensor unit(i.e.antenna and filter) and the PD test system,the PD statistical features at square voltages of different frequencies were obtained.Experimental results show that higher frequency will give rise,statistically,to PD of lower magnitudes distributing at smaller phases.A reasonable interpretation of this phenomenon was presented.Lastly,according to the PD statistical features,some suggestions for the PD detection system design,generator parameter optimization and the PD pulse extracting were given.The results of this work would be beneficial to the increase of the sensitivity when performing the PD detection on insulation systems for inverter-fed motors at repetitive square voltages and thus,improving the reliability of inverter-fed motors.     

某铁路π形梁桥的荷载试验研究

以某铁路桥为工程背景,通过结构计算、现场检测、荷载试验等工作,对铁路桥梁的荷载试验过程进行详细阐述,评估受检π形梁的工作性能和承载能力。结果表明,受检π形梁的承载能力能够满足设计荷载等级的要求。工程为π形梁的后期养护及维修提供了基础依据,对同类型铁路桥梁的检测及其承载能力评价有一定的参考价值。