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应用水力学和线性系统理论对问题进行分析,得出发生激振的临界条件式。就平移和旋转振型、有调压井和无调压井作示例计算,得到临界稳定曲线。解释了小缝隙漏水时更容易发生激振,与实际经验一致。计算了特征方程的根,获得振动频率和增长或衰减系数。 相似文献
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An aminophenol ligand, N,N,N'-tri(2-hydroxy-5-methylbenzyl)-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffract... 相似文献
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An aminophenol ligand, N,N,N′-tri(2-hydroxy-5-methylbenzyl)-1,2-ethanediamine, was prepared through the Mannich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffraction. The title compound (C26H32N2O3, Mr = 420.54) belongs to the monoclinic system, space group P21/n with a = 8.6233(14), b = 10.2655(16), c = 26.017(4) ′, β = 95.797(2)o, V = 2291.3(6) ′3, Z = 4, the final R = 0.0461 and wR = 0.1139 for 4267 unique reflections (Rint = 0.028) with 11691 observed ones (I > 2σ(I)). 相似文献
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本文提出了在坡度和密度为任意变化情形下求压力数值解的通用解法,作了多种变化因素和实际工程应用的计算,有一些与精确解作了对比。 相似文献
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A selective reaction of cyclohexanone oxime-blocked tolylene-2,4-diisocyanate(2,4-TDI)with amino siloxane was observed,in which amines were capable of discriminating two reactive groups in the 2,4-TDI molecule.Thus,tolylene-2-tert-butyldimethylsilyloxyethyl carbamide-4-cyclohexanone oxime carbamate was synthesized and its precise structure was determined by single-crystal X-ray diffraction.Moreover,it was found that oxime-blocked isocyanate could react selectively with the–NH2group with the–OH group unprotected in ethanolamine. 相似文献
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