A novel complex tri（o-bromobenzyl）tin ferrocenecarboxylate has been synthesized and its crystal structure was determined by X-ray diffraction. It belongs to orthorhombic, space group Pbca with a = 1.1340（3）, b = 1...A novel complex tri（o-bromobenzyl）tin ferrocenecarboxylate has been synthesized and its crystal structure was determined by X-ray diffraction. It belongs to orthorhombic, space group Pbca with a = 1.1340（3）, b = 1.7823 （4）, c = 3.0119（8） nm, V = 6.088（3） nm^3, Mr = 857.81,Z = 8, Dc = 1.872 g/cm^3,μ（MoKα） = 52.63 cm^-1, F（000） = 3328, R = 0.0683 and wR = 0.1057. The tin atom adopts a distorted tetrahedral coordination geometry. Further studies on the title complex have been performed with quantum chemistry calculation at the Lanl2dz basis set level using G98W package. The stability of the complex, some frontier molecular orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.展开更多
Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standard...Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standards. A number of analytical methods are presently used for the analysis of metals in the biochemical. The instrumental techniques available are Inductively Coupled Plasma (ICP/MS), X-Ray Fluorescence, UV-VIS Spectrophotometry, and Atomic Absorption Spectrometry. Flame AA has gained widespread acceptance as an analytical technique and is used for many applications. In this study, we have determined the amount of manganese metal present in Tricalcium Phosphate (TCP) using Flame Atomic Absorption Spectrophotometer. The method has high precision and accuracy. The percent recovery was found to be 99.8% for spiked sample. The results meet the requirement.展开更多
The tris[（2-methyl-2-phenyl）propyl]（2,4-dinitro-phenolato）tin was synthesized by the reaction of bis[tri（2-methyl-2-phenyl）propyltin] oxide with 2,4-dinitrophenol. The compound was characterized by IR, 1H NMR sp...The tris[（2-methyl-2-phenyl）propyl]（2,4-dinitro-phenolato）tin was synthesized by the reaction of bis[tri（2-methyl-2-phenyl）propyltin] oxide with 2,4-dinitrophenol. The compound was characterized by IR, 1H NMR spectra and elemental analysis. The crystal structure has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 0.9649（0）, b = 1.0087（8）, c = 3.4867（4） nm, β = 90.965（7） , Z = 4, V = 3.3933（7） nm3, Dc = 1.369 Mg·m-3, （MoKa） = 0.796 mm-1, F（000） = 1440, R = 0.0345 and wR = 0.0821. The tin atom has a distorted tetrahedral geometry. The 2D network structure of the complex is formed by hydrogen bonds and π-π effects. The stabilities, orbital energies and composition characteristics of some frontier molecular orbitals of the complexes have been investigated with the aid of G98W software.展开更多
Tri-training利用无标签数据进行分类可有效提高分类器的泛化能力,但其易将无标签数据误标,从而形成训练噪声。提出一种基于密度峰值聚类的Tri-training(Tri-training with density peaks clustering,DPC-TT)算法。密度峰值聚类通过类...Tri-training利用无标签数据进行分类可有效提高分类器的泛化能力,但其易将无标签数据误标,从而形成训练噪声。提出一种基于密度峰值聚类的Tri-training(Tri-training with density peaks clustering,DPC-TT)算法。密度峰值聚类通过类簇中心和局部密度可选出数据空间结构表现较好的样本。DPC-TT算法采用密度峰值聚类算法获取训练数据的类簇中心和样本的局部密度,对类簇中心的截断距离范围内的样本认定为空间结构表现较好,标记为核心数据,使用核心数据更新分类器,可降低迭代过程中的训练噪声,进而提高分类器的性能。实验结果表明:相比于标准Tritraining算法及其改进算法,DPC-TT算法具有更好的分类性能。展开更多
基金Supported by the Key Foundation of Education Committee of Hunan Province (06A009)the Natural Science Foundation of Hunan Province (05JJ40015, 06JJ50022)
文摘A novel complex tri（o-bromobenzyl）tin ferrocenecarboxylate has been synthesized and its crystal structure was determined by X-ray diffraction. It belongs to orthorhombic, space group Pbca with a = 1.1340（3）, b = 1.7823 （4）, c = 3.0119（8） nm, V = 6.088（3） nm^3, Mr = 857.81,Z = 8, Dc = 1.872 g/cm^3,μ（MoKα） = 52.63 cm^-1, F（000） = 3328, R = 0.0683 and wR = 0.1057. The tin atom adopts a distorted tetrahedral coordination geometry. Further studies on the title complex have been performed with quantum chemistry calculation at the Lanl2dz basis set level using G98W package. The stability of the complex, some frontier molecular orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.
文摘Tricalcium phosphate Anhydrous Powder typically contains less than 10 ppm (mg/Kg) (w/w) manganese. This level can be determined utilizing Flame Atomic Absorption Spectrometer (AAS) and standard based on known standards. A number of analytical methods are presently used for the analysis of metals in the biochemical. The instrumental techniques available are Inductively Coupled Plasma (ICP/MS), X-Ray Fluorescence, UV-VIS Spectrophotometry, and Atomic Absorption Spectrometry. Flame AA has gained widespread acceptance as an analytical technique and is used for many applications. In this study, we have determined the amount of manganese metal present in Tricalcium Phosphate (TCP) using Flame Atomic Absorption Spectrophotometer. The method has high precision and accuracy. The percent recovery was found to be 99.8% for spiked sample. The results meet the requirement.
基金the Natural Science Foundation of Hunan Province (No. 11JJ3021)the Innovation Platform Open fund of Hunan Provincial Education Department (No.09K099 and No. 10K010) and a key project (No. 10A014)+3 种基金the Hunan Provincial Scientific Program (No.2010JT4041)the open fund of the Key Laboratory of Functional Organometallic Materials of Colleges of Hunan Province (No.10K02)Hengyang Municipal Scientific Program (2011KG56)the Youth Program of Hengyang Normal University (No. 11A28)
文摘The tris[（2-methyl-2-phenyl）propyl]（2,4-dinitro-phenolato）tin was synthesized by the reaction of bis[tri（2-methyl-2-phenyl）propyltin] oxide with 2,4-dinitrophenol. The compound was characterized by IR, 1H NMR spectra and elemental analysis. The crystal structure has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 0.9649（0）, b = 1.0087（8）, c = 3.4867（4） nm, β = 90.965（7） , Z = 4, V = 3.3933（7） nm3, Dc = 1.369 Mg·m-3, （MoKa） = 0.796 mm-1, F（000） = 1440, R = 0.0345 and wR = 0.0821. The tin atom has a distorted tetrahedral geometry. The 2D network structure of the complex is formed by hydrogen bonds and π-π effects. The stabilities, orbital energies and composition characteristics of some frontier molecular orbitals of the complexes have been investigated with the aid of G98W software.
文摘Tri-training利用无标签数据进行分类可有效提高分类器的泛化能力,但其易将无标签数据误标,从而形成训练噪声。提出一种基于密度峰值聚类的Tri-training(Tri-training with density peaks clustering,DPC-TT)算法。密度峰值聚类通过类簇中心和局部密度可选出数据空间结构表现较好的样本。DPC-TT算法采用密度峰值聚类算法获取训练数据的类簇中心和样本的局部密度,对类簇中心的截断距离范围内的样本认定为空间结构表现较好,标记为核心数据,使用核心数据更新分类器,可降低迭代过程中的训练噪声,进而提高分类器的性能。实验结果表明:相比于标准Tritraining算法及其改进算法,DPC-TT算法具有更好的分类性能。
