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将碳纤维视为由微晶和无定型碳所构成的二相复合材料,以Mori-Tanaka方法研究了碳纤维微观结构对弹性模量的影响。对四种高模碳纤维M35JB、M40JB、M46JB及M55JB的微观量进行了测量。微晶的长细比由XRD实验测得,碳纤维石墨化程度由拉曼光谱分析得到。影响碳纤维弹性模量的因素包括:微晶的长细比、体积分数及取向度。通过计算细观力学模型得到了四种高模碳纤维的微晶体积分数。研究发现:碳纤维石墨化程度越高,微晶体积分数越大。碳纤维弹性模量随着微晶取向度、体积分数和长细比的增加而增加,且对这三种因素做了比较,微晶取向度和体积分数对弹性模量的影响高于微晶长细比对弹性模量的影响,只有当微晶取向度接近100%时,其对弹性模量的影响才有可能被微晶长细比超越。微晶取向度和体积分数增加的最初阶段,取向度对弹性模量的影响较大,随着两影响因素的增加,取向度对弹性模量的影响最终被体积分数超越。 相似文献
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本文对用球磨机冷混新2号岩石炸药工艺问题进行了探讨。从原材料水分、混药细度及混药均匀性等方面,分析了影响混药质量的因素。从安全、质量、劳动条件、生产效率诸方面,对球磨机冷混与轮碾机热混工艺进行了比较。 相似文献
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《低温工程》2021,(1)
以美国玫琳凯奥康纳过程安全中心(MKOPSC)的LNG泄漏实验为基础,建立了低温液体蒸气云扩散的数值计算模型,探究了水幕和蒸气云团之间的相互作用机理,在此基础上分析了水幕相关参数对气云扩散的影响。结果表明:水幕有助于蒸气云快速稀释到可燃极限以下,缩小危险区域范围;当水幕距泄漏源的距离为7 m、4.5 m和2 m时,可燃气云与地面的分离距离与无水幕工况相比分别缩短了26%、34%和49%;增加喷嘴流量能进一步缩短可燃气云与地面的分离距离,但其缩短速率逐步变小;水幕安装角度的增大会促进蒸气云的顺风向扩散,当安装角度大于45°时,甚至会超过无水幕工况时可燃气云的最大顺风向距离。 相似文献
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文中对2号岩石粉状铵梯炸药的原材料细度、混合均匀度、装药密度和混药温度等影响爆速的因素进行了探讨。 相似文献
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GTG起爆药性能研究 总被引:12,自引:4,他引:8
文章介绍了一种以碳酰肼为配体的配合物起爆药GTG,描述了GTG起爆药的基础性能和使用性能。该起爆药机械感度适中,对热作用和静电作用钝感,使用安全,具有良好的应用和发展前景。 相似文献
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The lifespan of a human is determined by inborn factors including genetic factors and acquired factors, such as social-environmental factors and individual-behavior. From this point of view, this study classified factors determining the economic lifespan of patents into inborn “genetic factors,” acquired “social-environmental factors,” as well as “individual-behavioral factors,” and analyzed the change in the influence intensity of factors with patent age along with application year. The results showed that the intensities of factors determining patent lifespan differed by industry and changed with the maintenance period and application year. Moreover, while “social-environmental factors” (such as a patent litigation), together with “individual-behavioral factors” (such as the number of patent family) had a stronger influence on patent lifespan than “genetic factors” (such as the number of claim), patents maintained longer period had stronger influence of behavioral and environmental factors rather than genetic factors. Furthermore, recently applied patents had a stronger influence due to the external environments than patents applied a relatively long time ago. 相似文献
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经典参数在多结构耦合系统统计能量分析中的应用 总被引:4,自引:0,他引:4
直接和间接耦合损耗因子是用统计能量分析方法研究多结构耦合系统振动响应的关键参数,也是急待解决的问题之一。本文提出了用经典统计能量分析参数计算多结构耦合系统的直接和间接耦合损耗因子的方法。其优点是利用经典统计能量分析已取得的成果解决了多子结构耦合系统的问题。文中首先推导了经典的双子结构耦合系统的耦合损耗因子和结构参数的关系,然后研究了多子结构耦合系统的直接和间接耦合损耗因子与结构参数的关系,最后推导得到多子结构耦合系统的直接和间接耦合损耗因子和经典统计能量分析中的耦合损耗因子的关系。以三子结构耦合系统为例进行了实验测量,直接、间接耦合损耗因子和结构振动响应的实验测量值与理论预测结果吻合较好。 相似文献
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对医药类包装设计的几点思考 总被引:1,自引:1,他引:0
从情感因素、创意因素、文化因素3个方面着手,对医药类的包装设计进行了探讨,对目前医药包装设计的现状及问题做了分析,并对我国医药类包装设计如何发展进行了展望和思考。 相似文献
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Recent contributions suggest that non-economic factors could be important motivational drivers of scientific mobility. We investigate this hypothesis in a sample of foreign researchers in Italy and Portugal, examining their willingness to leave the host country. We distinguish between economic factors, non-economic relational factors and non-economic aspirational factors. Controlling for the relevant contextual variables, we find that foreign researchers, unsatisfied with aspirational factors (e.g. level of independence, autonomy, intellectual challenge and social status), are more likely to leave their host country and move to a third country than they are to return to their countries of origin. Relational and economic factors, such as salary and benefits, do not demonstrate any additional impact. 相似文献
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目的 分析现有的快递包装循环利用观点,优化整合快递包装循环利用形式,调查各个阶段快递回收的流程及其可行性,整理出成本因素、材料因素、促进因素、社会因素4个因素,对比各因素对快递包装循环利用的影响程度。方法 通过去重优化方法和正交实验进行分析,采用直观分析法和方差分析法进行对比观察,得出各因素的重要程度。结果 对快递包装循环利用的影响从大到小依次为成本因素、材料因素、促进因素、社会因素,特别是成本因素影响最大,而社会因素的影响效果并不明显。结论4项因素的影响度排序可以提高现有的包装循环利用效率,提高资源利用率,保护生态环境,为利用快递包装循环的行业提供更加优化的选择。 相似文献
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G. S. Watson 《技术计量学》2013,55(3):371-388
This paper discusses the problem of group screening methods wherein f factors are sub-divided into groups of k factors each, forming g “group-factors”. The group factors are then studied using a Plackett and Burman design in Q + 1 runs. The two versions of the group factors are formed by maintaining all component factors at their upper and lonrer levels respectively. All factors in groups found to have a large effects are then studied in a second stage of experiments. The author discusses the problems of detection and false detection of factors, optimum group size, size of program, and the role of costs in this sequential form of experimentation. 相似文献
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James L. Gardner 《Journal of research of the National Institute of Standards and Technology》2007,112(3):129-138
Uncertainties in source color measurements with a tristimulus colorimeter are estimated for calibration factors determined, based on a known source spectral distribution or on accurate measurements of the spectral responsivities of the colorimeter channels. Application is to the National Institute of Standards and Technology (NIST) colorimeter and an International Commission on Illumination (CIE) Illuminant A calibration. Detector-based calibration factors generally have lower uncertainties than source-based calibration factors. Uncertainties are also estimated for calculations of spectral mismatch factors. Where both spectral responsivities of the colorimeter channels and the spectral power distributions of the calibration and test sources are known, uncertainties are lowest if the colorimeter calibration factors are recalculated for the test source; this process also avoids correlations between the CIE Source A calibration factors and the spectral mismatch factors. 相似文献