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91.
通过研究交换Ｂａｎａｃｈ代数Ａ与Ａ／ｒａｄＡ的关系,得到了Ａ具有谱延拓性质、强谱延拓性质、乘法Ｈａｈｎ＿Ｂａｎａｃｈ性质的充要条件．作为一个推论,当Ａ为半单时,得到Ｍｅｙｅｒ（１９９１）的结论． 相似文献
92.
ＴｈｅＤｉｆｆｅｒｅｎｃｅｏｆＥｌｅｃｔｒｏｎｉｃＰｒｏｐｅｒｔｉｅｓａｎｄｔｈｅＥｆｆｅｃｔｏｆＨｙｄｒｏｇｅｎ－ｂｏｎｄｏｆｃｉｓ－ａｎｄｔｒａｎｓ－ＰｏｌｙａｚｏｍｅｔｈｉｎｅＷＡＮＧＲｏｎｇ－ｓｈｕｎ，ＰＡＮＸｉｕ－ｍｅｉａｎｄＳＵＺｈｏｎｇ... 相似文献
93.
94.
Xiangyu Ma Yuyuan Bai Yongbo Song Qinzhen Li Ying Lv Hui Zhang Prof. Haizhu Yu Prof. Manzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17387-17391
Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size-evolution principles. Reported here is the largest known FCC-based (FCC=face centered cubic) silver nanocluster, [Ag100(SC6H33,4F2)48(PPh3)8]−: the first all-octahedral symmetric nesting Ag nanocluster with a four-layered Ag6@Ag38@Ag48S24@Ag8S24P8 structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC-based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC-based Russian nesting doll model constitutes a new platform for the study of the size-evolution principles of Ag NCs. 相似文献
95.
Dr. Min Luo Dr. Chensheng Lin Donghong Lin Prof. Ning Ye 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16112-16115
The first fluorosulfonic ultraviolet (UV) nonlinear optical (NLO) material, C(NH2)3SO3F, is rationally designed by taking KBe2BO3F2 (KBBF) as the parent compound. C(NH2)3SO3F features similar topological layers as KBBF by replacing inorganic (BO3)3− with organic C(NH2)3+ trigonal units and BeO3F with SO3F− tetrahedra. Therefore, C(NH2)3SO3F is a metal-free UV NLO crystal. Benefiting from the coplanar configuration of the C(NH2)3+ cationic groups, it possesses a large SHG response of 5×KDP and moderate birefringence of 0.133@1064 nm. Besides, it has a short UV cutoff edge of 200 nm. The calculated results reveal the shortest SHG phase-matching wavelengths can reach 200 nm. These findings highlight the exploration of metal-free compounds as nontoxic and low-cost UV NLO materials as a new research area. 相似文献
96.
Dong-Liang Zhang Cheng-Long Deng Bin Xie Yu-Long Li Chuan Lai Wen-Yu Mou Lin-Xin He Xiao-Xue Bai Tao Li Jia-Xi Cao Jun Wang 《应用有机金属化学》2020,34(1):e5261
Six new O-alkyldithiophosphate nickel complexes with dcpf ligand, [(dcpf)Ni(S2P{O}OR)] (dcpf = 1,1′-bis (dicyclohexylphosphino)ferrocene, R = CH3 ( 1 ), CH3CH2 ( 2 ), Ph ( 3 ), 4-MeC6H4 ( 4 ), PhCH2 ( 5 ) and PhCH2CH2 ( 6 )), have been synthesized by the treatment of dcpf with ((RO)2PS2)2Ni in satisfactory yields. These complexes were characterized by elemental analysis, spectroscopy (FTIR, UV–vis, 1H, 13C, and 31P NMR), thermogravimetric analysis and single crystal X-ray diffraction. The nickel atom in 1 , 2 ·CH2Cl2, 3 ·CH2Cl2, 4 ·2CH2Cl2·THF, and 2( 5 )·hexane adopts a slightly distorted square-planar coordination environment finished by two phosphorus atoms of dcpf ligand and two sulfur atoms of O-alkyldithiophosphate ligand. Furthermore, the electrochemical properties for complexes 1 – 6 were also investigated by cyclic voltammetry. With the addition of 120 mM trifluoroacetic acid (TFA), the turnover frequency (TOF) values for 1 – 6 are estimated to be 1243.83, 1046.54, 1331.71, 2545.29, 1899.03, and 1191.37 s−1, with the overpotential (η) values of 0.62, 0.58, 0.71, 0.67, 0.60, and 0.56 V, respectively. The result of electrochemical studies indicates that all complexes can be used as efficient molecular eletrocatalysts for the reduction of protons to hydrogen in the presence of TFA in MeCN. 相似文献
97.
Two new fluorescent coordination polymers based on pamoic acid and different polydentate N-donor ligands, namely {[Cd(PA)(TPTZ)(H2O)](DMF)2}n ( 1 ) and [Cd(PA)(BIB)]n ( 2 ) [H2PA = pamoic acid, TPTZ = 2,4,6-tri(2-pyridyl)-1,3,5-triazine, BIB = 1,4-bis(1-imidazolyl)benzene], were synthesized and characterized. Complex 1 showed a 1D zigzag chain structure with intramolecular hydrogen bonds. The 2D supramolecular structure in 1 was formed through π–π stacking interactions and intermolecular hydrogen bonds. Complex 2 displayed a 2D network structure. Intramolecular hydrogen bonds and π–π stacking interactions were observed in 2 . By studying the fluorescence sensing performance of two coordination polymers, complex 1 exhibited high selectivity for tracking Al3+ ion and complex 2 could discriminately detect inorganic or aliphatic amines with high selectivity. 相似文献
98.
Ning-Fang Li Jiuyang Ji Wei Jiang Jia-Peng Cao Ye-Min Han Peng Yuan Yan Xu 《无机化学与普通化学杂志》2020,646(10):463-468
The usage of the achiral ligand, in lanthanide chemistry, successfully obtained two series of chiral lanthanide complexes, formulated d - and l -{Gd[IN][HIN][CH2OCH2O]}n (abbreviated as Gd ) and d - and l -{Dy[IN][HIN][CH2OCH2O]}n (abbreviated as Dy , HIN = isonicotinic acid). Crystallographic researches determined that four compounds are all one-dimensional (1D) chain structures and crystallized in a chiral space group. In addition, CH2OHCH2OH acts as not only solvent but also the bridge ligand. Besides, single crystal circular dichroism (CD) spectra conformed compounds Gd-L and Gd-D , Dy-L and Dy-D are enantiomers respectively. Magnetically, compound Gd showed predominant magnetocaloric effect (MCE) of 26.20 J · kg–1 · K–1 at 2.5 K for ΔH = 7 T, while there is ferromagnetic interactions in compound Dy . 相似文献
99.
针对水平井、大斜度井钻井过程中井眼润滑性、岩屑携带以及钻井速度的影响等问题,通过合理的分子设计,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和实验室自制疏水单体丙烯酸正辛醇OA_8为原料,利用胶束聚合法,制备了一种弱凝胶成胶剂AMAMPSOA_8,其结构经1H NMR和IR表征。以AMAMPSOA_8在低剪切速率下的表观粘度为指标设计正交试验,确定最优反应条件为:AM与AMPS摩尔配比为4.8∶1,引发剂用量为单体总质量的0.04%,疏水单体浓度为0.75%,于70℃反应9 h。该条件下,0.5%AMAMPS0A_8聚合物溶液在低剪切速率3 r·min~(-1)下表观粘度可达23 680 mPa·s。利用热分析仪、高温滚子炉、高温高压流变仪对产物性能进行了研究。研究表明:AMAMPSOA_8的抗温性能可达160℃;聚合物溶液体系有明显的触变性,在40 min后溶液切力增加幅度变缓。 相似文献
100.
采用阳离子聚苯乙烯微球作为模板,钛酸四丁酯为钛源,氨水为催化剂,制备了中空TiO_2微球.采用X射线衍射、扫描电镜及比表面测定仪对其形貌和结构进行了表征,并考察了模板粒径、钛源用量以及催化剂用量对中空TiO_2微球形貌的影响.通过物理共混法将其引入至聚丙烯酸酯乳液中并成膜,研究了复合薄膜的保温性能、抗紫外性能及力学性能.结果表明,锐钛矿相中空TiO_2微球模板粒径、钛源用量以及催化剂用量影响中空TiO_2微球的空心尺寸、壁厚及壳层致密性.中空TiO_2微球可显著提升聚丙烯酸酯薄膜的保温性能、抗紫外性能和力学性能.采用不同粒径的模板制备的中空TiO_2微球对复合薄膜的各项性能均有影响,其中模板粒径为140 nm时复合薄膜性能最优,光反射率提升63%,导热系数降低27%,且在波长小于360 nm范围内,紫外透过率几乎为0,抗张强度增加100%,断裂伸长率提升62%. 相似文献