泄漏通信与立井井筒提升机信号闭锁功能开发

针对立井井筒作业安全系数要求较高的问题,开发了一种泄漏通信与提升机信号闭锁功能,用以实现在立井井筒检修过程中采用泄漏通信手持对讲机打点对提升机信号进行闭锁、解锁操作;详细介绍了通过提升机信号系统的改造和通过提升机电控系统的改造2种途径实现该闭锁功能的方案。实际应用表明,该功能实施后,立井井筒作业人员可直接参与提升机控制,不需要开车时即闭锁提升机信号,提高了立井井筒作业的安全性。     

煤矿井下采掘设备隔爆兼本安型电气控制箱的本安设计

针对煤矿井下采掘设备防爆兼本安型电气控制箱内本安电路与非本安电路并存、非本安电路的能量可能会窜入本安电路而影响本安电路防爆及本安性能的问题,从结构设计和电气隔离两方面介绍了煤矿井下采掘设备隔爆兼本安型电气控制箱的本安设计方法,给出了电气间隙、爬电距离、绝缘及耐压、接线端子、本安布线、电源变压器、本安隔离栅印制板等结构布置方法以及RS485通信隔离电路、模拟量隔离电路、压频变换电路、电阻信号隔离电路、开关量隔离电路、继电器隔离电路等电气隔离措施。应用表明,采用该方法设计的煤矿井下采掘设备隔爆兼本安型电气控制箱安全可靠,维护简便,能够满足煤矿井下的防爆要求。     

高压带电体温度检测装置

针对传统高压带电体测温方法存在的难以实现电气绝缘、精度低等问题,介绍了一种新型高压带电体温度检测装置的设计方案。该装置采用传统接触式测温方式下的温度传感器采集温度信号,采用可调电流源+感生电源方式实现供电,各感生电源与可调电流源通过高压线连接,不同测温点的感生电源之间没有电气连接,且采用光纤传输温度信号,从而很好地实现了电气绝缘。实验结果表明,该装置的感生电源电压稳定,测温精度高,抗干扰能力强。     

Roll‐to‐roll UV embossing process applied for light bar‐based sub‐wavelength gratings for backlight

This study proposes a roll‐to‐roll process‐based sub‐wavelength grating, which is attached on a light bar to turn the side‐lit red/green/blue (620, 520, and 450 nm) incident rays into a uniformly and normally output white light with high illuminance from the light bar's surface. On the basis of the rigorous coupling wave analysis, the relationship between the first‐order transmission/reflection efficiency and the pitch of the gratings with different shapes was analyzed. The optimal design can effectively reduce the coupling length and enhance the white color balance for display applications.     

Electrical conductivity,self-diffusion,and volume expansion of alkali halides at the melting point

In an earlier paper, Heisenberg's uncertainty principle was invoked at the melting point T _m of crystalline solids to provide fundamental justification for Lindemann's melting law and to compute diffusion coefficients of several alkali halides. The uncertainty principle defines breakdown of Debye zone boundary (ZB) phonons as valid collective excitations when phonon energies and line widths due to anharmonicity become comparable at T _m. Upon breakdown, random, high-frequency single-particle motion or partial decoupling of crystal ions sets in. Lifetimes of these single-particle ZB motions are determined from the minimum-uncertainty product inequality by assuming that it becomes an equality at T _m for ZB phonons. The present paper addresses improved formulation of that work and extended application to ionic electrical conductivities of 18 molten alkali halides at T _m. It is shown that use of the Debye model produces an approximate lower bound to the mean free time, not the unconstrained direct estimate previouslu implied. This feature is generally reflected in results for ionic conductivities and alkali halide diffusion coefficients for which comparison experimental data were found. However, in spite of this lower-bound formulation and the simple nature of the computation, the results compare favorably with experiment. A model of random single-particle harmonic motion superimposed on the lower-frequency collective motion is proposed to account for volume expansion accompanying the partial decoupling for hard-sphere ions. Experimental comparisons for 15 alkali halides show the decoupling volume change to account largely for the total volume change of melting (in the hard-sphere approximation), yielding a closer agreement with experiment than recent calculations aimed explicitly at the total volume change.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

A universal dependence for thermal conductivity of metals and dilute alloys

A universal curve relating the maximum of thermal conductivity and its respective temperature with the residual electrical resistivity has been proposed for metals and dilute alloys. Based on the equation of that curve, a comparative analysis of selected literature data of thermal conductivity of metals, which have residual electrical resistivity in the range 10^–11<₀<10^–5. cm, have been performed. Using the data for 33 metals, confirmation of the Wiedemann-Franz law for the impurity component/T of thermal conductivity was obtained, which means that _th/_el1, where _th and _el are the parameters of the electron-lattice defect interaction obtained from measurements of thermal and electrical conductivity, respectively. Examples of the failure of the Wiedemann-Franz law are also presented, exhibiting the values of _th/_el in the range 0.16 to 25. Measurements of thermal conductivity in the range 2 to 20 K and determination of the residual electrical resistivity for the samples of Cd doped with Zn and quenched were performed, resulting in values _th/_el1.     

深海带电插拔连接器力学特性分析

以水下7 000 m工况的深海带电插拔连接器为研究对象,旨在获得湿插拔连接器在深海双重高压下的受力特性和插拔过程中的动密封性能。介绍连接器的插头结构与压力补偿技术;推导压力补偿器工作容积的计算公式;运用Ansys Workbench建立插头内壳体组件与插孔组件的动密封有限元模型,对内壳体、压力平衡膜及内胆进行强度计算;分析由连接器插拔引起的平衡膜内外瞬时压差对膜的应力分布及变形情况;讨论密封件径向压缩量、密封接触面摩擦因数、插拔速度对插拔过程中动密封性能的影响。结果表明:插头插合时,平衡膜外表面应力基本不变,其变形减小;拔出时,平衡膜外表面的应力及变形都逐渐增大。密封件之间的接触压力受密封接触面过盈配合量的影响明显,增大过盈配合量可显著提高动密封区域的接触压力及密封性能,同时也会加剧密封件失效的可能性,密封接触面的摩擦因数、插拔速度对接触压力的影响则较小。     

热压烧结Ti3AlC2材料的制备、结构与性能研究

采用热压工艺研究了不同工艺制度和原料中不同的Si含量对Ti3AlC2合成的影响.研究表明在1 300℃～1 500℃,30MPa压力和Ar气氛中热压摩尔比为n(TiC)n(Ti)n(Al)n(Si)=2110.2的混合粉末,可以得到纯度达98%(质量分数)以上的致密块体Ti3AlC2材料;添加的Si均匀分布在基体中,形成固溶体,当添加Si的摩尔比为0.2时,固溶体的化学式为Ti2 76Al0 78Si0.22C2.烧结试样的晶体为层片状结构,1 300℃和1 400℃时,烧结试样的晶粒尺寸分别为10μm～15μm和20μm～30μm.材料的维氏硬度为3.3 GPa～5.0 GPa,弹性模量为289 GPa,抗压强度为785 MPa,抗弯强度为375 MPa,断裂韧性为7.0 MPa·m1/2;25℃时,电导率为3.1×106 S·m-1,热容为125.4 J/mol·K,热导率为27.5 W/m·K;热膨胀系数为8.8×10-6 K-1.     

综合管廊电气工程的相关问题研究

城市综合管廊是现代城市建设的重要综合系统,其电气工程设计工作需要关注供电电源、接地系统、照明设计、电气设备防潮、电缆敷设等关键环节。     

不同添加剂对AgSnO2In2O3触头材料电性能的影响

采用内氧化法工艺制备了不含添加剂及分别含添加剂CuO或TeO2的3种AgSnO2In2O3触头材料。应用模拟继电器试验设备检测了这3种材料在AC230 V、25 A阻性负载条件下的电寿命、熔焊力、电弧能量、燃弧时间、质量侵蚀率等相关电性能参数,并对检测结果及试验后铆钉触头样品进行了分析。研究发现:与不含添加剂的AgSnO2In2O3材料相比,添加剂CuO对材料的电寿命影响不大,而添加剂TeO2明显提高了材料的电寿命;含添加剂的两种材料的熔焊力和电弧能量均有了不同程度的降低,但它们的质量侵蚀率却明显增加。