Reactions of the preformed cluster precursor [Et4N]2[Mo2S2(μ-S)2(edt)2] (edt = ethanedithiolate) (1) with [Au(PPh3)Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4(AuPPh3)...Reactions of the preformed cluster precursor [Et4N]2[Mo2S2(μ-S)2(edt)2] (edt = ethanedithiolate) (1) with [Au(PPh3)Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4(AuPPh3)(edt)2]·0.25Et2O·0.25MeOH (2·0.25Et2O·0.25MeOH). It was characterized by elemental analysis, IR spectrum and X-ray analysis. 2·0.25Et2O·0.25MeOH crystallizes in the monoclinic system, space group C2/c with a = 20.117(4), b = 9.2705(19), c = 44.418(9) A^°, β= 93.19(3)°, V = 8271(3) A^°^3, Z = 8, Dc = 1.794 g/cm^3, T = 193 K, C31.25H43AuMo2NO0.50PS8, Mr = 1116.96, F(000) = 4380, μ(MoKa) = 4.603 mm^-1, S = 1.019, R = 0.0672 and wR = 0.1708 for 7243 observed reflections with I 〉 2σ(I). The anion of 2 consists of a butterfly-shaped Mo2S4Au core in which one [AuPPh3]^+ cation is coordinated by one bridging S and two terminal S atoms of the [(edt)2Mo2(S)2(μ-S)2] moiety. The Au(I) center adopts a pseudo-tetrahedral coordination geometry, and the Au-S bond lengths vary from 2.425(2) to 2.898(3)A^°.展开更多
为了解决源数据维数较大的问题,提出了一种基于非负矩阵分解(NMF)的同调机群识别方法。采用发电机角速度作为源数据,使用NMF算法对其进行降维。由于此低维矩阵具有非负性质,因而该模型在消除冗余数据、降低维数的同时,保留了原始问题的...为了解决源数据维数较大的问题,提出了一种基于非负矩阵分解(NMF)的同调机群识别方法。采用发电机角速度作为源数据,使用NMF算法对其进行降维。由于此低维矩阵具有非负性质,因而该模型在消除冗余数据、降低维数的同时,保留了原始问题的实际意义。对低维矩阵归一化,再利用K均值聚类算法对其进行聚类,达到同调机群的分群目的。通过New England 10机39节点系统比较了基于NMF和主成分分析方法的分群效果,验证了基于NMF的同调机群识别方法的有效性。展开更多
基金supported by the National Natural Science Foundation of China (No. 20525101 and 20871088)the "SooChow Scholar" Program and Program for Innovative Research Team of Suzhou University
文摘Reactions of the preformed cluster precursor [Et4N]2[Mo2S2(μ-S)2(edt)2] (edt = ethanedithiolate) (1) with [Au(PPh3)Cl] in MeOH/MeCN gave rise to a new heterobimetallic Mo/Au/S cluster [Et4N][Mo2S4(AuPPh3)(edt)2]·0.25Et2O·0.25MeOH (2·0.25Et2O·0.25MeOH). It was characterized by elemental analysis, IR spectrum and X-ray analysis. 2·0.25Et2O·0.25MeOH crystallizes in the monoclinic system, space group C2/c with a = 20.117(4), b = 9.2705(19), c = 44.418(9) A^°, β= 93.19(3)°, V = 8271(3) A^°^3, Z = 8, Dc = 1.794 g/cm^3, T = 193 K, C31.25H43AuMo2NO0.50PS8, Mr = 1116.96, F(000) = 4380, μ(MoKa) = 4.603 mm^-1, S = 1.019, R = 0.0672 and wR = 0.1708 for 7243 observed reflections with I 〉 2σ(I). The anion of 2 consists of a butterfly-shaped Mo2S4Au core in which one [AuPPh3]^+ cation is coordinated by one bridging S and two terminal S atoms of the [(edt)2Mo2(S)2(μ-S)2] moiety. The Au(I) center adopts a pseudo-tetrahedral coordination geometry, and the Au-S bond lengths vary from 2.425(2) to 2.898(3)A^°.
文摘为了解决源数据维数较大的问题,提出了一种基于非负矩阵分解(NMF)的同调机群识别方法。采用发电机角速度作为源数据,使用NMF算法对其进行降维。由于此低维矩阵具有非负性质,因而该模型在消除冗余数据、降低维数的同时,保留了原始问题的实际意义。对低维矩阵归一化,再利用K均值聚类算法对其进行聚类,达到同调机群的分群目的。通过New England 10机39节点系统比较了基于NMF和主成分分析方法的分群效果,验证了基于NMF的同调机群识别方法的有效性。