T形件单向螺栓连接方钢管柱-H形钢梁抗弯节点性能研究

在对方钢管柱-H形钢梁顶底T形钢单向螺栓连接节点进行了单调静力加载试验基础上，利用ABAQUS软件进行有限元分析，通过对比验证了有限元模拟结果的准确性。基于试验节点（BASE节点）模型，通过改进节点构造，建立5个系列的节点有限元模型，以模拟分析不同构造下的节点性能。研究结果表明，增加柱壁厚度能够明显提高节点的初始转动刚度和极限承载力，柱壁厚度超过14 mm时会发生单向螺栓的剪拉破坏，节点的变形性能下降；设置加劲肋能明显提高节点的极限承载力，但加劲肋厚度对节点性能影响不大；对梁翼缘以及腹板进行合理削弱能够保证节点的极限承载力和初始转动刚度。在实际的工程应用中，可考虑对梁进行合理削弱，以提高钢材利用率，节约钢材

C-2v-Symmetric C-60 Isomer in the Gas Phase: Experimental Evidence against Buckminsterfullerene (I-h-C-60)

Pure non-IPR (isolated-pentagon-rule) C-60 isomer has rarely been investigated experimentally. The recently reported availability of (C60Cl8)-C-#1809 opens an avenue for experimental investigation of C-#18098(60), a C-2v-symmetric C-60 isomer having two pairs of fused pentagons. Herein, the experiments on C-#1809(60) were performed oil the basis of thermal dechlorination of (C60Cl8)-C-#1809 in the solid state and gas phase. (C60Cl6)-C-#1812 was employed for comparative study. As determined by Raman and other methods, C-#1809(60) from thermal decomposition of (C60Cl8)-C-#1809 crystals readily coalesces to form carbon solid with a collapsed crystal lattice. In contrast, dechlorination via thermal spray of (C60Cl8)-C-#1809 in the gas phase is feasible for investigation of monodispersed all-carbon C-60 isomer, because the existence of C-#1809(60) in the gas phase has been confirmed by experimental evidence from mass spectrometry and high-perfomance-liquid-chromatography.National Natural Science Foundation of China 20525103,20531050,20721001 973 Program,2007CB81530