国外柔性制造系统发展概况

柔性制造系统FMS是六十年代开始开发的一种先进制造系统,近十多年来得到迅速发展。它以电子技术和计算机技术为基础,具有高效率、高柔性、高精度的优点,适用于中,小批量、多品种生产。该文概述了FMS的基本内容、特点及其发展历史与动向。     

层流保温法

挪威科研人员提出一种改进双层玻璃窗保温作用的新方法:在两层玻璃间的上框架上开若干平行的沟槽,这样就使室内的暖空气沿内层玻璃的外侧向下流动,室外的冷空气则沿外层玻璃的内侧向下流动,两股气流在公共表面上通过分子阴渗方式进行热交换,在气流稳     

火箭发射用的薄膜管

英国研制出一种薄膜管,正用于阿里安火箭发射装置。将这种薄膜管装于火箭与发射塔之间,在火箭点火前数分之一秒钟,脱开发射塔。薄膜管成本低,质轻柔软,可承受每小时     

我国将引进先进标准

最近召开的第三次全国工业技术进步会议确定,七五计划期间,技术进步规划的内容之一,就是引进4500种新的质量与测量国家标准,从而使我国国标超过12000种。其中半数可以     

远红外点焊监控

美国ITT研究所制定中心研制出远红外点焊监控装置。这在点焊的实时监视与反馈校正方面是一个突破。它可随时分析内部缺陷,检测点焊熔核,及时调整焊接参数。在焊接     

用于拦截的核火箭枪

美国西屋汉福特公司根据星球大战计划,研制一种核能火箭枪,用于拦截敌人导弹.它包括小核反应堆与液氢火箭.反应堆发出足够的热能使火箭产生高速.与其它动能防御系统相比,核火箭有四个优点:(1)反应堆工作时间短,因此安全可靠.当火箭发出后,反应堆自动停止工作.(2)核能直接转换为热能,不需用电.(3)由于液氢推进剂重量极     

Biological and cognitive determination of the gravitational reference frame

It is argued that space sickness is not so much a physiological problem, but a psychological one, having its roots in the perception of the environment, and its associated cognitive processing. This cognitive processing is argued to be that of field dependence and field independence, for which exist psychobiological and cognitive assessment tests. Since there is an obvious economic advantage in the use of cognite testing, it is recommended that this could be used as an initial screening when selecting for astronauts.     

带锯切割

正确选用带锯可以顺利、快速、精确地进行切割，获得优质切口，减少换锯次数。与此相反，选用带锯不当，则会影响切割乃至产生废品。正确选用带锯取决于以下因素：被切割材料的硬度、尺寸与形状以及带锯质量。考虑到这些因素后，即可确定带锯结构、齿形、齿距及其应用条件。 关键的第一步是鉴别被切割材料，每种材料有其不同的切割条件。即使是较软的玻璃纤维与石墨复合材料也有磨蚀作用，足以磨损锯片。显然，金属材料硬度更高，每种合金都有各自的切割条件。 锯片齿槽大小取决于被切割材料。切割铝、黄铜、青铜等软的可锻有色金属…     

Plant molecular biology in the space station era: utilization of KSC fixation tubes with RNAlater

Spaceflight experiments involving biological specimens face unique challenges with regard to the on orbit harvest and preservation of material for later ground-based analyses. Preserving plant material for gene expression analyses requires that the tissue be prepared and stored in a manner that maintains the integrity of RNA. The liquid preservative RNAlater (Ambion) provides an effective alternative to conventional freezing strategies, which are limited or unavailable in current spaceflight experiment scenarios. The spaceflight use of RNAlater is enabled by the Kennedy space center fixation tube (KFT), hardware designed to provide the necessary containment of fixatives during the harvest and stowage of biological samples in space. Pairing RNAlater with the KFT system provides a safe and effective strategy for preserving plant material for subsequent molecular analyses, a strategy that has proven effective in several spaceflight experiments. Possible spaceflight scenarios for the use of RNAlater and KFTs are explored and discussed.     

国外企业技术改造概况

振兴经济,发展生产,必须依靠科学进步,用新的科学技术不断改造企业,可以说工业发展的过程,就是对企业进行技术改造的过程。据估计,西方国家提高劳动生产率诸因素中,技术改造所占的比重,在全产业中为60％,在纺织工业中为40％,在钢铁工业中为88％,在机械工业中为70％。因此企业的技术改造,其重要性是显而易见的。战后日本,西德工业迅速恢复、发展、美苏在工业上保持领先地位,一个重要原因就是重视企业的技术改造。