排序方式: 共有7条查询结果,搜索用时 31 毫秒
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首先,概述了以不改变全尺寸静待性实验台整体结构为前提。在原有实验台上添加激振装置和测试仪器。增加动特性功能的必要和可能性。其次,概述了脉冲激励、振动测量、数据采集主动特性识别的基本原理,最后将测量结果与理论计算作了比较,并讨论了可能产生误差的各种原因。 相似文献
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减水剂对建筑石膏作用效果影响因素的研究 总被引:5,自引:0,他引:5
为了提高建筑石膏中减水剂的使用效率,试验研究了建筑石膏比表面积、减水剂掺法、pH值等因素对建筑石膏分散性和强度的影响,并对其影响规律进行了分析。结果表明适当增加建筑石膏细度可提高减水剂的使用效率;不同掺法的减水剂作用效果存在较大差异,先掺法效果最好;pH值对减水剂分散效果有一定影响,在弱碱性条件下减水剂分散效果最好。 相似文献
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Weights allocation methods are critical in Multi-Criteria Decision Making. Given numerical importances for each involved criterion, direct normalizing those numerical importances to obtain weights for those criteria is plain, lack of flexibility, and thus cannot well model some more types of subjective preferences of different decision makers like Dominance Strength as defined in this study. We show that concave RIM quantifier Q based OWA weights allocation method can well handle and model such preference. However, in real decision making those numerical importances are very often embodied by uncertain information such as independent random variables with discrete or continuous distributions, statistic information and interval numbers. In any of those circumstances, simple RIM quantifier Q based OWA weights allocation cannot work. Therefore, in this study, we will propose some special dynamic weights allocation methods to gradually allocate weights and accumulate allocated parts to each criterion, and finally, obtain a total weights collection. When the uncertain numerical importances become equivalent to general real numbers, the method automatically degenerates into general RIM quantifier based OWA weights allocation. The innovative weight allocations have discrete and continuous versions: the former can be well programmed while the latter has neat and succinct mathematical expression. The method can also be widely used in many other applications like some economic problems including investment quota allocation for one’s favorite stocks, and the dynamic OWA aggregation for interval numbers. 相似文献
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With the development of the manufacturing technology, a challenge has been proposed on the joining of difficult welding materials and the poor connection interface of materials. In this paper, rotary swaging technology is utilized as a joining by plastic deformation forming method to join tube/tube parts with different diameters. Experimental set-up of rotary swaging forming was designed and fabricated, in which the forging energy can be adjusted by changing the rotation speed of AC server motor. The rotary swaging model and tension testing model are established by using FE simulation software Forge 2D. The effects of forming parameters on the tension strength of the joined tubes and the joining mechanism are investigated. The results show that a concave arc joint can be formed at the overlapping parts of the tubes. To obtain the high joining strength, the distance from the end of the inner tube to the center of the hammer die need to exceed a certain value. The maximum strain and stress occur at the concave arc joining region in which the thickness variation of the two joined tubes is small. To exam the joining strength, the tension test was performed. The two tubes tend to slide out during tension process and the maximum stress occurs at the relative sliding region. The ratio on tensile load of the joined tubes to the maximum tensile load of the single tube can reach to 68% for the inner tube and 47% for the outer tube. Therefore, the joining strength of the tube/tube parts, formed by using rotary swaging method, is enough high. 相似文献
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Tong YuQi Cheng BingJun Miao YuanQing Zhou Bin Zhu XingHong Yang YanYan Liu Ji Gou XiaoChen Zhang YiTeng Wang JinDong Li Lei Magnes Werner Lammegger Roland Pollinger Andreas Zeren Zhima Shen XuHui 《中国科学:技术科学(英文版)》2021,64(10):2328-2336
Science China Technological Sciences - High precision magnetometer (HPM) is a magnetic field detection payload onboard China Seismo-Electromagnetic Satellite (CSES), including two fluxgate... 相似文献
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