太阳热反射涂料在建筑节能中的研究

太阳热反射涂料对太阳辐射具有较高反射率,将其涂覆于建筑围栏结构,可以降低空调负荷或改善室内热舒适环境。研究了不同围栏结构材料对太阳热反射涂料节能效果的影响。     

多级维修供应下可修复备件库存建模与优化

针对虚警情况下可修复备件库存配置量虚高、各级站点库存配置偏离需求的问题,结合Metric理论,分析两级可修复备件保障过程的特征,引入维修过程中虚警故障鉴别系数,修正各级保障站点备件需求均值。考虑故障维修及虚警鉴别所产生的费用,并在满足系统绩效指标要求下,建立以保障费用最小为目标的库存配置模型。采用边际优化算法进行数值分析,通过对比是否包含虚警情况的备件库存配置方案,证明考虑虚警情况的模型能够提高对两级可修复备件库存配置量的预估精度。

     

Note: Optical fiber milled by focused ion beam and its application for Fabry-Pérot refractive index sensor

We introduce a highly compact fiber-optic Fabry-Pérot refractive index sensor integrated with a fluid channel that is fabricated directly near the tip of a 32 μm in diameter single-mode fiber taper. The focused ion beam technique is used to efficiently mill the microcavity from the fiber side and finely polish the end facets of the cavity with a high spatial resolution. It is found that a fringe visibility of over 15 dB can be achieved and that the sensor has a sensitivity of ~1731 nm/RIU (refractive index units) and a detection limit of ~5.78 × 10(-6) RIU. This miniature integrated all-in-fiber optofludic sensor may find use in minimal-invasive biomedical applications.     

预氧化+热循环气体渗氮工艺在阀门上的应用

介绍了预氧化 +热循环气体渗氮新工艺及原理。该工艺生产周期短 ,渗氮速度快 ,是一种较好的气体渗氮工艺     

聚丙烯(PP)热压变形行为研究

从技术上分析了结晶型PP在Tg~Tm(Tf)温度区间变形的相(结构)-(凝聚)态意义,使用黄金分割法在其Tg~Tm(Tf)温度区间划分低温和高温双相热固态变形温度区域,同时设计3种热压实验温度,并沿用冷压变形研究的镦粗变形模式和试样对PP进行4种变形速度和3种变形程度的热压变形实验。实验结果表明,提高PP热压变形温度和变形速度可以产生温度软化和速度粘化效应以及速度缩减回弹效果,从而大幅度降低冷压PP的变形回弹并改善其定形性,并有可能使PP高速热锻技术实现实用目标。     

Mechanical property evaluation of high burn-up nuclear fuel cladding using the ring tensile test

In order to evaluate the degradation of the mechanical properties of Zr-based nuclear fuel cladding tubes under severe accident conditions such as a RIA (reactivity initiated accident) and LOCA (loss of coolant accident), mechanical tests that can properly simulate the degradation of these properties are needed. In the present paper, modified ring tensile tests were performed in order to evaluate the mechanical properties of high burn-up fuel cladding under a hoop loading condition in a hot cell. The tests were performed with Zircaloy-4 nuclear fuel cladding, which has a burn-up of approximately 65,000 MWd/tU in a temperature range of room temperature to 800 °C. As the first step, the hoop loading grip for the ring tensile test was designed such that a constant curvature of the specimen could be maintained during the deformation, and graphite lubricant was used to minimize the friction between the outer surface of the die insert and the inner surface of the ring specimen. The specimen for the ring tensile test was designed to limit the deformation within the gauge section and to maximize the uniformity of the strain distribution. It was confirmed that the mechanical properties under a hoop loading condition can be correctly evaluated by using this test technique. In this study, experimental results on the ductility and toughness degradation of Zircaloy-4 fuel cladding tubes under a hoop directional mechanical load simulating the RIA condition are presented.     

高精度偏心斜孔的多轴数控加工方法

在分析产品图纸的基础上,比较了高精度偏心斜孔的各种常用加工方法的优缺点,选定五轴数控加工中心作为加工设备,介绍了其加工工艺方法和程序的编制。实际运行结果显示,采用此方法能满足偏心斜孔的精度要求,降低了生产成本,提高了生产效率。     

Development of a precision indentation and scratching system with a tool force and displacement control module

This article presents a tip-based micropatterning system with a precision device for measuring the machine force and the tool path. The machine force is obtained by a tool control module with a leaf spring and a capacitive displacement sensor. It is controlled to provide a force that ranges from 80 microN to 8 N. The force sensing unit, which is part of the module, is mounted on a PZT (PbZrTi) driven in-feed motion stage with a resolution of 1 nm. The work piece is set on an X-Y motion stage, and the position can be controlled with a tool path accuracy of 5 nm. Micropatterning and precision indentation experiments were performed, while the machined surfaces were examined by atomic force microscopy. From these results, the feasibility of the system for precise force-displacement control was verified for application in tip-based precision machining.