A new complex [Ni（en）3]4[HVⅣ12VⅤ6O42（PO4）] has been hydrothermally synthesize d and characterized by X-Ray diffraction,IR and Elemental analysis.Single crystal X-ray analysis indicates that this compoud cry stal...A new complex [Ni（en）3]4[HVⅣ12VⅤ6O42（PO4）] has been hydrothermally synthesize d and characterized by X-Ray diffraction,IR and Elemental analysis.Single crystal X-ray analysis indicates that this compoud cry stallizes in cubic system,space group Im3m with a=17.4081（2）*!,V=5275.38（10）*! 3 ,R=0.0420,w R=0.1055,Z =2,D c =1.663g·cm -3 ,μ=2.297mm -1 ,F（000）=2636.The crystal structure consis ts of[Ni （en） 3 ] 2+ cations and{HV 18 O 42 （PO 4 ）} 8- cluster anion which construct from 18{VO 5 }.square pyramids.The VO 5 pyramids joined each other to form a {V 18 O 42 }cage hosting a tetrahedral{PO 4 } 3- moiety with disordered oxygen atoms .CCDC:185574.展开更多
The title compound H2SiW12O40·(CH3)2NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X ray diffraction. The crystal belongs to mo...The title compound H2SiW12O40·(CH3)2NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X ray diffraction. The crystal belongs to monoclinic, space group C2/m, a=2.0654(4)nm, b=1.3306(3)nm, c=1.3194(3)nm, β=119.59(3)°, V=3.1531(11)nm3, Dc=3.606Mg·m-3, Z=2, R=0.0462, Rw=0.0836. The title compound comprises of a 2+ unit, a polyanion and a free (CH3)2NH molecule. The ESR spectrum of the title compound shows that charge transfer between organic groups and polyanion takes place under irradiation of the sunlight in solid state. The TG study of the title compound shows that it had four stages of the weight loss, and the increase of the decomposition temperature for the polyanion shows that the stability of the polyanion was enhanced due to the influence of Zn2+ ion. CCDC:175866.展开更多
A composite of 60% of lanthanum stearate and 40%（mass fraction） of stearic acid was prepared and its influence on the crystallization characteristics of isotatic polypropylene （iPP） was investigated. The results s...A composite of 60% of lanthanum stearate and 40%（mass fraction） of stearic acid was prepared and its influence on the crystallization characteristics of isotatic polypropylene （iPP） was investigated. The results showed that we had found a new kind of β-crystalline form nucleating agent. The composite might induced rather high proportion of β-modification. The relative content of β-phase estimated by WAXD and DSC was 30% and 51.8% in a PP containing 2.5%（mass fraction） of the composite respectively. The isothermal crystallization at 130 ℃ and melting behavior examined by DSC revealed that the composite accelerated the overall rate of crystallization remarkably. The half crystallization period t1/2 decreased from 11 8 min of pure PP to 7 5 min of PP containing 2.5% of the composite. However, the composite had no obvious influence on crystallization mode and the size of α-crystal unit cell.展开更多
有序碳和无序碳都普遍被用作硅(Si)的复合材料。但是具有不同结晶度和孔结构的碳对硅基负极电化学性能的影响仍存在争议。本工作在严格控制碳含量和表面官能团的基础上,选择沥青(Pitch)和酚醛树脂(PR)作为有序碳和无序碳的前驱体,制备...有序碳和无序碳都普遍被用作硅(Si)的复合材料。但是具有不同结晶度和孔结构的碳对硅基负极电化学性能的影响仍存在争议。本工作在严格控制碳含量和表面官能团的基础上,选择沥青(Pitch)和酚醛树脂(PR)作为有序碳和无序碳的前驱体,制备了硅碳复合材料(Si@C)并系统地研究了其电化学行为。有序的晶体结构有利于复合物中的电子传输,中孔和大孔有利于锂离子的扩散。具有有序结构和小孔容的碳质涂层为Si的膨胀提供了很好的缓冲,电极在50次循环后仍保持结构完整性。然而,无序和多孔的结构降低了结构的稳定性并产生了很大的极化,这使得循环过程中体积不断膨胀,导致电化学性能较差。Si@C-Pitch在5 A g^(−1)下的容量是Si@C-PR的8倍,在0.5 A g^(−1)下100次循环后的容量保持率是Si@C-PR的1.9倍。该研究可为Si@C负极中炭材料的选择提供了理论指导。展开更多
文摘A new complex [Ni（en）3]4[HVⅣ12VⅤ6O42（PO4）] has been hydrothermally synthesize d and characterized by X-Ray diffraction,IR and Elemental analysis.Single crystal X-ray analysis indicates that this compoud cry stallizes in cubic system,space group Im3m with a=17.4081（2）*!,V=5275.38（10）*! 3 ,R=0.0420,w R=0.1055,Z =2,D c =1.663g·cm -3 ,μ=2.297mm -1 ,F（000）=2636.The crystal structure consis ts of[Ni （en） 3 ] 2+ cations and{HV 18 O 42 （PO 4 ）} 8- cluster anion which construct from 18{VO 5 }.square pyramids.The VO 5 pyramids joined each other to form a {V 18 O 42 }cage hosting a tetrahedral{PO 4 } 3- moiety with disordered oxygen atoms .CCDC:185574.
文摘The title compound H2SiW12O40·(CH3)2NH was synthesized in mixed solvent of aqueous and acetonitrile, and its crystal structure had been determined using single crystal X ray diffraction. The crystal belongs to monoclinic, space group C2/m, a=2.0654(4)nm, b=1.3306(3)nm, c=1.3194(3)nm, β=119.59(3)°, V=3.1531(11)nm3, Dc=3.606Mg·m-3, Z=2, R=0.0462, Rw=0.0836. The title compound comprises of a 2+ unit, a polyanion and a free (CH3)2NH molecule. The ESR spectrum of the title compound shows that charge transfer between organic groups and polyanion takes place under irradiation of the sunlight in solid state. The TG study of the title compound shows that it had four stages of the weight loss, and the increase of the decomposition temperature for the polyanion shows that the stability of the polyanion was enhanced due to the influence of Zn2+ ion. CCDC:175866.
文摘A composite of 60% of lanthanum stearate and 40%（mass fraction） of stearic acid was prepared and its influence on the crystallization characteristics of isotatic polypropylene （iPP） was investigated. The results showed that we had found a new kind of β-crystalline form nucleating agent. The composite might induced rather high proportion of β-modification. The relative content of β-phase estimated by WAXD and DSC was 30% and 51.8% in a PP containing 2.5%（mass fraction） of the composite respectively. The isothermal crystallization at 130 ℃ and melting behavior examined by DSC revealed that the composite accelerated the overall rate of crystallization remarkably. The half crystallization period t1/2 decreased from 11 8 min of pure PP to 7 5 min of PP containing 2.5% of the composite. However, the composite had no obvious influence on crystallization mode and the size of α-crystal unit cell.
文摘有序碳和无序碳都普遍被用作硅(Si)的复合材料。但是具有不同结晶度和孔结构的碳对硅基负极电化学性能的影响仍存在争议。本工作在严格控制碳含量和表面官能团的基础上,选择沥青(Pitch)和酚醛树脂(PR)作为有序碳和无序碳的前驱体,制备了硅碳复合材料(Si@C)并系统地研究了其电化学行为。有序的晶体结构有利于复合物中的电子传输,中孔和大孔有利于锂离子的扩散。具有有序结构和小孔容的碳质涂层为Si的膨胀提供了很好的缓冲,电极在50次循环后仍保持结构完整性。然而,无序和多孔的结构降低了结构的稳定性并产生了很大的极化,这使得循环过程中体积不断膨胀,导致电化学性能较差。Si@C-Pitch在5 A g^(−1)下的容量是Si@C-PR的8倍,在0.5 A g^(−1)下100次循环后的容量保持率是Si@C-PR的1.9倍。该研究可为Si@C负极中炭材料的选择提供了理论指导。
基金supported by grants from The National Natural Science Foundation of China(81402850)the Special Scientific Research Project of Education Department of Shaanxi Provincial Government(17JK0669)~~
