1mN·m～1N·m扭矩标准装置力臂系统

介绍了新研制的1 mN·m~1 N·m扭矩标准装置的关键部件——力臂系统的设计方案,并对力臂进行了不确定度分析。分析表明:1 N·m扭矩标准机力臂长度的不确定度为4.2×10~(-6)(k=2),完全满足1 N·m扭矩标准机技术指标的要求。     

1mN·m～1N·m扭矩国家基准装置的建立

介绍了项目"1mN·m～1N·m扭矩国家基准装置的建立"的立项背景、基本情况和项目取得的成果及主要创新。该项目采用了多项自主研发的关键技术,成功研制了国内首台基于空气轴承支撑技术的全自动高准确度微小扭矩标准装置,该装置复现的扭矩值范围为1mN·m～1N·m,扭矩值不确定度(k=2)在100mN·m～1N·m范围内小于5×10~(-5);在5mN·m～100mN·m范围内小于1×10~(-4);在1mN·m～5mN·m内小于5×10~(-4)。     

Low density steel 1·2C–1·5Cr–5Al designed for bearings

Abstract

A novel alloy design, designated as 1·2C–1·5Cr–5Al, has been proposed with high aluminium(～5 wt-%) and more carbon(～1·2 wt-%) addition into the classical 1C–1·5Cr bearing steel for lowering density and improving performance simultaneously, which is approximate 8 wt-% lighter than convention. In order to understand preliminarily the suitability of the novel alloy for bearing application, the martensite starting temperature and hardness, related to microstructure evolution and mechanical properties, respectively, after partial austenitisation treatment with undissolved carbides have been investigated carefully. The martensite starting temperature is comparable with conventional 1C–1·5Cr alloy. The hardness of 860±3 HV20 achieved is much higher than convention.     

Wear perfornance of 0·6%Cr alloyed cast and heat treated steels with carbon contents of 0·7, 1·0, and 1·3%

Abstract

The effect of carbon content and heat treatment on the abrasive wear performance of three 0·6%Cr alloyed cast steels with carbon contents near the eutectoid composition (0·7, 1·0 and, 1·3%) were investigated using a pin on drum abrasion tester. Specimens were austenitised at 870,970, or 1070°C for 1 h and quenched. Additionally, a 1·3%C specimen was spheroidised, then austenitised at 870°C and quenched. The microstructure, which was dependent on heat treatment and carbon content, significantly influenced the wear rate. The wear rate is related non-linearly to hardness. The lowest wear rate was obtained for the 1·3%C alloy austenitised at 1070°C producing a quenched microstructure of 40% retained austenite and 60% martensite. This specimen also exhibited the lowest quenched hardness. However, for a practical industrial heat treatment, the 1·0 %C alloy austenitised at 970°C provides the best wear performance.

MST/3130     

假如生活没标准······

正这个假设,当然只是假设而已,是为了叙述方便,生活中根本不可能出现这样的情况。即便是人类初期,也有那个时代与之对应的规则,亦即标准。人类从来都是群居的生灵,有自己独特的体制。而只要体制存在,就必然被规则所统治。一切体制,不论是政治体制、教育体制、宗教体制还是家庭体制,都笼罩在规则的大幕之下。所以说,规则就是所有参与者要想被体制接受并幸存下来而必须遵循的规范——不管形诸文字的,或者约定成俗的,都是如此。     

Welding of rapidly solidified Alloy 8009 (Al–8·5Fe–1·7Si–1·3V): preliminary study

Abstract

Alloy 8009 is a rapidly solidified, dispersion strengthened Al–8·5Fe (wt-%) alloy designed for high temperature (up to 400°C) aerospace applications. Both fusion and solid state joining techniques were shown to produce bonds. Fusion techniques destroyed the base metal microstructure with primary Fe₃Al, loss of solute, formation of larger aluminium grains, and the formation of grain boundary FeAl₃ and intermetallics enriched with silicon and vanadium. Solid state friction stir welding did not cause a significant modification to the dispersoid population but there was a loss of solute to dispersoid/matrix interfaces.

MST/3500     

化学技术·产业经济略语(1)

随着科学技术的发展,有关的新名词、新略语层出不穷。为方便读者查阅,本刊自本期起将连载“化学技术和产业经济略语”。该略语原刊登于日本《MOL 化学技术誌10月别册》145—231(1985)。考虑到原文篇幅太长,为了节省版面,避免与以前出版的化工略语重复,我们请译者仅就“英汉化学化工略语词典”(1975年9月版,石油化学工业出版社)中未曾收集的部分略语进行了翻译和注释。限于时间和水平,译文中难免有不妥之处,望广大读者谅解并指正。     

Phase relation of LaFe 11·6 Si 1·4 compounds annealed at different high-temperature and the magnetic property of LaFe 11·6– x Co x Si 1·4 compounds

LaFe _11·6 Si _1·4 compounds are annealed at different high temperatures from 1323 to 1623?K. The powder X-ray diffraction patterns show that large amount of NaZn₁₃-type phase begins to be observed in LaFe _11·6 Si _1·4 compound after being annealed at 1423?K for 5?h. In the temperature range from 1423 to 1523?K, the $\boldsymbol{\alpha} $ -Fe and LaFeSi phases rapidly decrease to form 1:13 phase. LaFeSi phase is rarely observed in the XRD pattern in the LaFe _11·6 Si _1·4 compound annealed at 1523?K (5?h). With annealing temperature increasing to 1573?K and 1673?K, La ₅ Si ₃ phase is detected, and there is a certain amount of LaFeSi phase when the annealing temperature is 1673?K. The amount of impurity phases in the LaFe _11·6 Si _1·4 compound annealed by the two-stage annealing consisting of high temperature ( $\boldsymbol{>}$ 1523?K) and 1523?K is larger than that of the single stage annealing at 1523?K under the same time. According to the results of different high-temperature annealing, LaFe $_{{\bf 11{\cdot}6}-\boldsymbol{x}}$ Co $_{\boldsymbol{x}}$ Si _1·4 ( $\boldsymbol{0{\cdot}1} \boldsymbol{\le} \boldsymbol{x} \boldsymbol{\le} \boldsymbol{0{\cdot}8}$ ) compounds are annealed at 1523?K (5?h). The main phase is NaZn13-type phase, and the impurity phase is a small amount of $\boldsymbol{\alpha} $ -Fe in LaFe $_{{\bf 11{\cdot}6}-\boldsymbol{x}}$ Co $_{\boldsymbol{x}}$ Si _1·4 compounds. With increase in Co content from $\boldsymbol{x} \boldsymbol{=} \boldsymbol{0{\cdot}1}$ to $\boldsymbol{0{\cdot}8}$ , the Curie temperature $\boldsymbol{T}_{\!\boldsymbol{\rm C}}$ , goes up from 207 to 285?K. The introduction of Co element weakens the itinerant electron metamagnetic transition, and also results in the change of magnetic transition type from first to second order at about $\boldsymbol{x = 0{\cdot}5}$ . The magnetic entropy change decreases from 19·94 to 4·57?J /kg K with increasing Co concentration at a low magnetic field of 0?C2?T. But the magnetic hysteresis loss around $\boldsymbol{T}_{\!\boldsymbol{\rm C}}$ reduces remarkably from 26·2?J /kg for $\boldsymbol{x = 0{\cdot}1}$ to 0?J /kg for $\boldsymbol{x} \boldsymbol{=} \bf 0{\cdot}8$ .     

古浪警方侦破“1·23”电信诈骗案

<正>假冒国家卫生计生委工作人员,向受害者讲述国家对老年人扶贫补贴相关政策,谎称可以用货到付款的方式,向受害者免费邮寄保健品,并缴纳一定数额的保证金后,受害者即可领取大额扶贫补贴。自2016年9月以来,犯罪嫌疑人用以上手法连续骗取甘肃省古浪县一黄姓老人8万余元。当地警方接到报警后,多警联合作战,通过深入串并分析、视频追踪、信息联查等方式在河北省保定市成功打掉一个以销售保健品送国家补贴为名的电信诈骗团     

Insoluble phase in Al–1·52Cu–0·75Mg alloys containing silicon

Abstract

Insoluble particles present in solution treated, quenched and aged Al–1·52Cu–0·75Mg alloys containing 0·23, 0·49, 0·76, and 1·03 wt-% Si have been investigated. Back-scattered scanning electron microscope images of polished sections of the alloys showed the presence of very small, nearly spherical particles at the grain boundaries of all alloys except that containing 0·23 wt-% Si. Alloys with 0·76 and 1·03 wt-% Si also contained large particles of well defined geometrical shapes. An electrolytic technique was used to extract the insoluble particles from the matrix. The extracted particles were analysed by energy dispersive X-ray analysis in a scanning electron microscope. They contained 20·6±0·4%Cu, 32·6±0·4%Mg, 30·2±0·4%Si, and 16·6±0·1%Al (all wt-%). X-ray diffraction analysis of these particles showed that they have a hexagonal structure with lattice parameters a=1·036±0·004 nm and c=0·404±0·004 nm. The insoluble particles were identified as quarternary phase Q. Aging for extended periods at 190°C did not alter the composition or morphology of the insoluble particles.

MST/661     

简讯·动态·信息·文摘

简讯·动态·信息·文摘·１９９５年度机械工业部科学技术进步奖最近公布。机械部广州电器科学研究所季勇、李士龙、孙碧波等人负责的“空调器生产用成套检测设备的开发与应用”项目荣获二等奖。·上海上菱电器股份有限公司与日本三菱电机株式会社合资组建空调机电器公司...     

Thermal properties and devitrification behaviour of (1+x)CaO·(1−x)MgO·2SiO2 glasses

The thermal properties (glass transformation, T _g, and softening, T _s, temperatures), the crystalline phases formed during heating in a differential thermal analysis (DTA) apparatus, the kinetic parameters and the mechanism of the devitrification process, of glasses of the system diopside-wollastonite were investigated. The substitution of CaO by MgO induces an increase in T _g and the crystal growth activation energy, E _c; this is probably linked to the greater coordination number of Ca^z+ ions with respect to the Mg²⁺ ions. The substitution of CaO by MgO lowers the nucleation rates of the diopside phase; wollastonite solid solution nuclei form whose growth appears to leave a glassy matrix in which diopside formation is inhibited. Only surface nucleation was observed, but, in finely powdered samples, which soften and efficiently sinter before devitrifying, surface nuclei behave as bulk nuclei. When bulk crystallization occurs, the Avrami parameter m was found to be 2 for all glasses, except the diopside one, for which m=3.     

效益·档次·规模·水平

如何真正把包装企业推向市场,使之在市场竞争中取胜?这不仅是企业主体要解决好的最现实的问题,也是摆在各级领导面前的一个紧迫课题。为此,本文就此谈几点认识: 立足企业上效益.提高产品市场占有率。要做到这一点。就必须指导企业把握三个环节:一是要适应市场。要确立为市场而生产,为效益而生产的指导思想,做到什么赚钱就搞什么。市场     

信息·简讯·动态·文摘

《蛋品冷库建设标准》审查会于1993年7月6日至9日在广东省广州市召开。会议由原商业部基建储运司应志增处长主持,参加会议的有部分省市基建、管理、设计、学术团体、投资公司等单位的工程技术管理人员以及《蛋品冷库建设标准》编写组成员共22     

机械·家电·照相机·图

众所周知，现代照相机是集光学、机械、电子于一体的精密仪器，但从分类上讲又很难将它归属于其中的哪一类。不是不伦不类而是有板有眼，与人类生活密切相关的生产量巨大的一类可重复使用性商品。因此有损坏的可能，有修理的价值，围绕修理又有许多说王道四的地方。做为拥有照相机的消费者来讲，担心的不是使用而是修理，但做为修理者来讲担心的既是修理，又是使用。照相机为什么会坏？怎样坏的？这是我们共同的疑问。但我归结为两个字“书、图”即说明书和说明图。对于机械产品，就拿最名的自行车来讲．有说明书和说明图，尽管人们都不再需…     

识别·认知·唯一·烙印

当所有技术和设施都日趋一致的时候,设计被看作是一种赋予更多新意和丰富视觉感受、信息资源的途径.品牌价值的不断攀升及新市场的层出不穷,要求更多企业或机构建造自身的企业文化和鲜明的形象系统.合理的战略思维在被赋予强有力的创造力表现之后,则会使之在喧嚣的市场环境中异军突起,势不可挡.