The self-consistent electronic structure calculations were carried out with the accurate frozen-core full-potential projector augmented-wave method on 13 Ni-Pt intermetallic compounds of simple crystalline structures,...The self-consistent electronic structure calculations were carried out with the accurate frozen-core full-potential projector augmented-wave method on 13 Ni-Pt intermetallic compounds of simple crystalline structures,i.e. A15,D019,D03 and L12 Ni3Pt and NiPt3,and α-NiAs,B1,B2,L2a,and L10 NiPt. The calculations reveal that the L12 Ni3Pt,L10 NiPt and L12 NiPt3 are energetically more stable than their respective competitive structures,indicating that the three structures may be formed in some appropriate conditions. The obtained results match well with the experimental observation or other theory predictions. It is found that there is hybridization between Ni 3d and Pt 5d states,which may significantly affect the structural stability and magnetism of metastable Ni-Pt intermetallic compounds.展开更多
High quality ultrafine Si powders have been synthesized from SiH4 by laser induced gas phase reaction. The powders prduced under different synthesis conditions have mean particle size of 10-120nm in diam. with narrow ...High quality ultrafine Si powders have been synthesized from SiH4 by laser induced gas phase reaction. The powders prduced under different synthesis conditions have mean particle size of 10-120nm in diam. with narrow particle size distribution, and free of hard agglomerates.The powders are polycrystalline with the ratio of mean grain to particle diameter being between 0.3-0.7. The size of the powder increases with increasing laser power and reaction pressure,but decreases with increasing silane gas flow rate and the addition of Ar diluent. Grain sizes drop distinctly with the rise of the addition of Ar gas and laser power, but change little with the gas flow rate and reaction temperature. The formation of Si particles under different synthesis conditions is discussed展开更多
Under hydrothermal conditions, the reaction of UO2(NO3)2·6H2O with ligand 4-cyanopyridine N-oxide in the presence of NaN3 affords one complex, {[(POTZ)2(H2O)3(UO2)](H2O) (1) (POTZ=4-tetrazolyl pyridine N-oxide), ...Under hydrothermal conditions, the reaction of UO2(NO3)2·6H2O with ligand 4-cyanopyridine N-oxide in the presence of NaN3 affords one complex, {[(POTZ)2(H2O)3(UO2)](H2O) (1) (POTZ=4-tetrazolyl pyridine N-oxide), which is another example of a pyridine N-oxide complex of uranium and exhibit strong green fluorescent emission at room temperature. The structure was determined by single crystal X-ray diffraction. Crystal data: P21/m, a=0.664 16(10) nm, b=2.104 1(3) nm, c=0.683 29(10) nm, β=93.295(3)°, V=0.953 3(2) nm3, Z=2, R1=0.033 7, wR2=0.083 3. CCDC: 241841.展开更多
The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the ti...The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the title compound belongs to triclinic, space group P1 with a=1.089 7(3) nm, b=1.050 33(4) nm, c=1.858 5(4) nm, α=96.822(4)°, β=94.477(4)°, γ=94.636(3)°, V=3.001 3(12) nm3, Z=4, Dc=1.679 Mg·m-3, μ(Mo Kα)=1.582 mm-1, S=1.005, F(000)=1 496, R1=0.040 7, wR2=0.076 3. In compound, the tin atom has a distorted tetrahedral coordination configuration. The molecules are packed in one-dimensional chain polymer through a weak interaction between the chlorine atoms from adjacent molecules, respectively. CCDC: 286106.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50531040, 50871058)the Ministry of Science and Technology of China (Grant No. 2006CB605201)the Administration of Tsinghua University
文摘The self-consistent electronic structure calculations were carried out with the accurate frozen-core full-potential projector augmented-wave method on 13 Ni-Pt intermetallic compounds of simple crystalline structures,i.e. A15,D019,D03 and L12 Ni3Pt and NiPt3,and α-NiAs,B1,B2,L2a,and L10 NiPt. The calculations reveal that the L12 Ni3Pt,L10 NiPt and L12 NiPt3 are energetically more stable than their respective competitive structures,indicating that the three structures may be formed in some appropriate conditions. The obtained results match well with the experimental observation or other theory predictions. It is found that there is hybridization between Ni 3d and Pt 5d states,which may significantly affect the structural stability and magnetism of metastable Ni-Pt intermetallic compounds.
文摘High quality ultrafine Si powders have been synthesized from SiH4 by laser induced gas phase reaction. The powders prduced under different synthesis conditions have mean particle size of 10-120nm in diam. with narrow particle size distribution, and free of hard agglomerates.The powders are polycrystalline with the ratio of mean grain to particle diameter being between 0.3-0.7. The size of the powder increases with increasing laser power and reaction pressure,but decreases with increasing silane gas flow rate and the addition of Ar diluent. Grain sizes drop distinctly with the rise of the addition of Ar gas and laser power, but change little with the gas flow rate and reaction temperature. The formation of Si particles under different synthesis conditions is discussed
文摘Under hydrothermal conditions, the reaction of UO2(NO3)2·6H2O with ligand 4-cyanopyridine N-oxide in the presence of NaN3 affords one complex, {[(POTZ)2(H2O)3(UO2)](H2O) (1) (POTZ=4-tetrazolyl pyridine N-oxide), which is another example of a pyridine N-oxide complex of uranium and exhibit strong green fluorescent emission at room temperature. The structure was determined by single crystal X-ray diffraction. Crystal data: P21/m, a=0.664 16(10) nm, b=2.104 1(3) nm, c=0.683 29(10) nm, β=93.295(3)°, V=0.953 3(2) nm3, Z=2, R1=0.033 7, wR2=0.083 3. CCDC: 241841.
文摘The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the title compound belongs to triclinic, space group P1 with a=1.089 7(3) nm, b=1.050 33(4) nm, c=1.858 5(4) nm, α=96.822(4)°, β=94.477(4)°, γ=94.636(3)°, V=3.001 3(12) nm3, Z=4, Dc=1.679 Mg·m-3, μ(Mo Kα)=1.582 mm-1, S=1.005, F(000)=1 496, R1=0.040 7, wR2=0.076 3. In compound, the tin atom has a distorted tetrahedral coordination configuration. The molecules are packed in one-dimensional chain polymer through a weak interaction between the chlorine atoms from adjacent molecules, respectively. CCDC: 286106.
