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In selecting rational types of underground structures resisting explosion, in order to improve stress states of the structural section and make full use of material strength of each part of the section, the research method of composite structures is presented.Adopting the analysis method of micro-section free body, equilibrium equations, constraint equations and deformation coordination equations are given. Making use of the concept of generalized work and directly introducing Lagrange multiplier specific in physical meaning,the validity of the constructed generalized functional is proved by using variation method.The rational rigidity matching relationship of composite structure section is presentedthrough example calculations. 相似文献
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在地下抗爆结构动力计算中,结构变形速度的作用是非常突出的.考虑结构变形速度的作用,所建立的结构体系运动微分方程可以真实地描述结构振动的实际情况.文中通过一维平面波理论,导出了作用在结构周边上的荷载表达式,给出了地下曲杆结构动力分析的广义变分原理,同时还进行了数值计算结构的对比分析. 相似文献
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以聚苯乙烯(PS)微球为内核,通过控制正硅酸乙酯的水解过程制备具有不同壳层形态的核/壳结构PS/SiO2复合磨料,应用于二氧化硅介质层的化学机械抛光,借助AFM测量抛光表面的形貌、轮廓曲线及粗糙度.SEM和TEM结果显示:碱性水解条件下,复合磨料的壳层由SiO2纳米颗粒组成(非连续壳层);酸性条件下,复合磨料的壳层则呈无定型网状(连续壳层).抛光对比试验结果表明:复合磨料的PS弹性内核有利于降低表面粗糙度并减少机械损伤,SiO2壳层则有利于提高材料去除率,复合磨料的核/壳协同效应对于提高抛光质量具有主要影响.相对于非连续壳层复合磨料,具有连续壳层的PS/SiO2复合磨料能够得到更低的抛光表面粗糙度值(RMS=0.136 nm),且在抛光过程中表现出了更好的结构稳定性.然而,PS/SiO2复合磨料的壳层形态对抛光速率的影响则不明显. 相似文献
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The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures.
The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure
will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression
of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground
arched-bar structures is given. At the same time, the results of the numerical calculation are compared.
Biography: ZHAO Xiao-bing (1975-) 相似文献
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Based on investigation into four aspects of qualitative mechanical analysis,principle model experiments, engineering dynamic load tests and numerical calculation, itwas discussed that the transfer of stresses and accelerations in stratum medium have a closerelation with its relative rigidity. The concepts of stresses and accelerations transfer in solidmedium and its corresponding generalized, composite structure system are presented. Thesurvivability of underground engineerings and protective engineering will be greatly increasedif these concepts are correctly used in construction. 相似文献
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以无水乙醇为溶剂,氨水为催化剂,利用正硅酸乙酯(TEOS)水解,并在500℃下煅烧1h,制备了SiO2粉体.将SiO2粉体作为内核浸渍到以硝酸亚铈、乙酰丙酮和正丙醇为原料制备的铈溶胶中,得到包覆型CeO2@SiO2复合粉体.利用XRD、SEM、TEM和FT-IR等测试手段,对所制备样品的物相结构、形貌、粒径大小、团聚情况进行表征.将所制备的包覆型CeO2@SiO2复合粉体配制成抛光浆料用于砷化镓晶片的化学机械抛光,用原子力显微镜(AFM)观察抛光表面的微观形貌,测量表面粗糙度.结果表明,采用浸渍工艺成功制备出单分散球形,粒径在400~450nm,负载均匀的包覆型CeO2@SiO2复合粉体.复合粉体中CeO2的包覆量随着铈溶胶中铈离子浓度的升高而增大.经包覆型CeO2@SiO2复合磨料抛光后的砷化镓晶片表面的微观起伏更趋于平缓,在1μm×1μm范围内表面粗糙度Ra值为0.819nm,获得了具有亚纳米量级粗糙度的抛光表面. 相似文献
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