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基于经典薄板理论和von Kármán非线性理论,采用Hamilton原理,首先建立了含集中质量矩形薄板的动力学方程,并结合Galerkin法进行模态截断,获得双模态非线性动力学控制方程组;随后,运用多尺度法,引入频率失调参数,重点研究了主共振与1∶3内共振联合作用下系统的非线性动力学特性,获得了幅-频特性表达形式。根据振动同步性以及幅-频曲线的极值特性,在分析参数范围内,发现当集中质量为0.06kg时,第一阶幅频曲线非线性现象衰减,且第二阶幅频曲线取到最小值。最后实例以集中质量作为调谐参数,分析了质量变化对振幅的影响,计算结果表明,质量在某一范围内对主共振与1∶3内共振联合下的第一阶模态振幅影响较小,但对第二阶模态振幅有较强的调制作用。 相似文献
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文献报导了Zr-BPR-Zeph体系的显色反应,但异配络合物报导很少。我们发现丙二酸(MLA)能与Zr(Ⅳ)、BPR形成金属-显色剂-掩蔽剂类型的异配络合物,在OP存在下有较高的灵敏度和选择性。实验部份 1.主要试剂和仪器:1.0×10~(-3)MBPR乙醇溶液(50%乙醇);0.5MMLA水溶液;2.0%OP水溶液;pH5.5乙酸-乙酸钠缓冲液;20μg ZrO_2/ml的1M盐酸锆标准溶液。721型分光光度计。 相似文献
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The stresses and strains are calculated for CT specimen of power hardening material in 3-D deformation state using ADINA finite
element program, and the stress distribution at the vicinity of crack tip for Mode I fracture is analysed according to the
results of calculation. It is found that the expression of stress can be written as the form of separation of variables of
r and θ, then the function of r can be expanded in Laurant series. It is still found that the three normal stresses have the
same order of magnitude. The conclusions offer two suppositions to obtain the theoretical expression of stress at the vinicity
of crack tip for Mode I fracture with good ground, and the procedure of solution will be greatly simplified.
This Work is Supported by the National Science Found. 相似文献
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用数字模拟方法研究了耦联一级不可逆随后化学反应的可逆、准可逆及不可逆表面吸附体系的循环伏安响应.建立了有关数字模型.模拟计算得到不同无量纲动力学参数时电流函数-电位极化曲线.给出了测定电荷传递速率常数k和随后反应速率常数中k1的方法.并研究了对甲氧基偶氮苯在酸性介质中的伏安响应,结果尚好. 相似文献
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基于集值统计的直觉模糊聚类 总被引:1,自引:0,他引:1
针对聚类问题中样品属性值不能或很难直接给出的情况,提出了一种基于集值统计的直觉模糊聚类方法,讨论了四种情况下的属性直觉模糊相似矩阵的公式,给出了聚类方法的步骤,最后通过算例 对该方法进行了说明和分析. 相似文献
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Size-Dependent Melting Behaviour of Nanometre-Sized Pb Particles Studied by Dynamic Mechanical Analysis
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Nanometre-sized (hereafter nano-) Pb particles embedded in an Al matrix are prepared by ball milling. It is found that the size of nano-Pb particles was decreased with increasing milling time. The melting behaviour of nano-Pb particles embedded in the Al matrix is studied by means of dynamic mechanical analysis, and a single internal friction peak in the vicinity of Pb melting temperature is observed. The onset temperature of the peak moves to lower temperature with the decrease of particles size and the internal friction peak height is increased, which indicates a size-dependent melting behaviour of nano-Pb particles. It is suggested that the size-dependent melting behaviour is associated with surface melting. 相似文献