Synthesis and structure of molybdenum-citrato cluster mu(2)-S bridge

A new molybdenum-citrato cluster containing [Mo2O2(mu-S)(2)(C6H5O7)(C6H4O7)](5-) anion was synthesized and characterized by elemental analysis, IR, UV-Vis spectra, XPS and X-ray diffraction. The parameters of the crystal structure of the compound are monoclinic, space group P2(1)/c, a = 2. 376 6(5) nm, b = 1. 327 4(3) nm, c = 2. 247 1(5) nm, beta = 118. 21 degrees, V = 6. 247(2) nm(3), Z = 8, D-c = 2. 128 g/cm(3), F(000) = 3 984, mu = 1 694 cm(-1), R = 0. 083 1 and R-2,R-w = 0. 154 9. The anion is binuclear molybdenum-citrato complex with mu(2)-S bridge. Each molybdenum atom pocesesses a distorted octahedral struture, which is coordinated with a terminal oxygen, two sulfur atoms, three oxygen atoms of hydroxyl, alpha-carboxylate, beta-carboxylate from citrate.

Equivalent Model Of Expansion Of Cement Mortar Under Sulphate Erosion

The expansion property of cement mortar under the attack of sulfate ions is studied by experimental and theoretical methods. First, cement mortars are fabricated with the ratio of water to cement of 0.4, 0.6, and 0.8. Secondly, the expansion of specimen immerged in sulphate solution is measured at different times. Thirdly, a theoretical model of expansion of cement mortar under sulphate erosion is suggested by virtue of represent volume element method. In this model, the damage evolution due to the interaction between delayed ettringite and cement mortar is taken into account. Finally, the numerical calculation is performed. The numerical and experimental results indicate that the model perfectly describes the expansion of the cement mortar.

渤海4号钻井船的疲劳损伤计算与分析

文章对渤海４号钻井船在我国渤中、辽东湾、东海和南海４大海域作业的疲劳损伤进行了详细的计算和分析，讨论了平台薄弱部位桩靴加强程度对平台疲劳损伤大小的影响及海流对平台损伤的作用。最后对渤海４号进行了充分的技术经济评价，为今后平台的合理使用、经济使用、安全作业提出了重要的建议。

涠11-4平台结构动态响应监测结果分析(涠11-4平台原位监测研究之二)

本文总结了针对涠１１－４平台一年多时间的应变和加速度监测数据的处理分析工作，详细介绍了所用的数据处理方法，给出了应变数据的统计结果及长期分布规律。通过对应变和加速度信号进行频谱分析，揭示了平台在多种环境条件下的振动特性。

涠11-4平台综合强度监测技术及实施运行系统(涠11-4平台结构原位监测研究之一)

本文介绍了一种固定式导管架平台综合强度监测系统，它用于对涠１１－４平台关键部位的应力、加速度及与结构响应相关的环境参数进行长期监测。讨论的重点内容是结构响应的测量方案、设备及实施方法，并对运行结果作了说明