X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0...X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.展开更多
The possibility of using finite atomic functions of Kravchenko-Rvachev for description of the laws of distribution of the refractive index of the troposphere,the intensity of the scattering from the sea,seasonal behav...The possibility of using finite atomic functions of Kravchenko-Rvachev for description of the laws of distribution of the refractive index of the troposphere,the intensity of the scattering from the sea,seasonal behavior unit radar cross section(RCS)of land areas with vegetation covering,as well as the spectrum of electromagnetic spikes of lithospheric origin is considered.展开更多
Let X and Y be real Banach spaces.Suppose that the subset sm[S1(X)] of the smooth points of the unit sphere [S1(X)] is dense in S1(X).If T0 is a surjective 1-Lipschitz mapping between two unit spheres,then,under some ...Let X and Y be real Banach spaces.Suppose that the subset sm[S1(X)] of the smooth points of the unit sphere [S1(X)] is dense in S1(X).If T0 is a surjective 1-Lipschitz mapping between two unit spheres,then,under some condition,T0 can be extended to a linear isometry on the whole space.展开更多
Let T be a mapping from the unit sphere S[l^p（Г）] into S[l^p（△）] of two atomic AL^p- spaces. We prove that if T is a 1-Lipschitz mapping such that -T[S[l^p（Г）]] belong to T[S[l^p（Г）]], then T can be linear...Let T be a mapping from the unit sphere S[l^p（Г）] into S[l^p（△）] of two atomic AL^p- spaces. We prove that if T is a 1-Lipschitz mapping such that -T[S[l^p（Г）]] belong to T[S[l^p（Г）]], then T can be linearly isometrically extended to the whole space for p 〉 2; if T is injective and the inverse mapping T^-1 is a 1-Lipschitz mapping, then T can be extended to be a linear isometry from l^p（Г） into l^p（△） for 1 〈 p ≤ 2.展开更多
This paper describes syntheses and structure determination of four lanthanide complexes [Nd(2-Cl-4-FBA) 3 phen] 2 (1, 2-Cl-4-FBA = 2-chloro-4-fluorobenzoate, phen = 1,10-phenanthroline), [Ln(2,5-DClBA) 3 phen] 2 (Ln =...This paper describes syntheses and structure determination of four lanthanide complexes [Nd(2-Cl-4-FBA) 3 phen] 2 (1, 2-Cl-4-FBA = 2-chloro-4-fluorobenzoate, phen = 1,10-phenanthroline), [Ln(2,5-DClBA) 3 phen] 2 (Ln = Sm(2) and Tb(3), 2,5-DClBA = 2,5-dichlorobenzoate) and [Sm(2-Cl-4,5-DFBA) 3 (phen)(H 2 O)] 2 (4, (2-Cl-4,5-DFBA = 2-chloro-4,5-difluorobenzo- ate). The complexes were characterized by elemental analysis, infrared and ultraviolet spectra, and X-ray single-crystal diffraction. In the molecular structures of 1 4, two Ln 3+ ions are linked by four carboxyl groups, with two of them in a bridging bidentate mode and the other two in a bridging-chelating tridentate mode, forming four binuclear molecules. In addition, each Ln 3+ ion is also chelated to one phen molecule and one carboxyl group in the complexes, except each Sm 3+ ion in 4 which is bonded to one carboxyl group by unidentate mode and one H 2 O molecule. There are two different coordination polyhedrons for each Nd 3+ ion in the two similar molecular structures of 1 and they are a distorted monocapped square antiprismatic and a distorted tricapped triangular prism conformation, respectively. The coordination polyhedron for each Ln 3+ ion in 2 4 is a nine-coordinated distorted mono-capped square antiprismatic conformation. The complex 3 exhibits green luminescence under the radiation of UV light. The thermal decomposition behaviors of the complexes have been discussed by simultaneous TG/DSC-FTIR technique. The 3D surface graphs for the FTIR spectra of the evolved gases were recorded and the gaseous products were identified by the typical IR spectra obtained at different temperatures from the 3D surface graphs. Meanwhile, we discussed the nonisothermal kinetics of 1 4 by the integral isoconversional non-linear (NL-INT) method.展开更多
基金supported in part by Program for New Century Excellent Talents in University of China (No. NCET-10-0133)Innovation Scientists and Technicians Troop Construction Projects of Henan Province (No. 114100510004)
文摘X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.
文摘The possibility of using finite atomic functions of Kravchenko-Rvachev for description of the laws of distribution of the refractive index of the troposphere,the intensity of the scattering from the sea,seasonal behavior unit radar cross section(RCS)of land areas with vegetation covering,as well as the spectrum of electromagnetic spikes of lithospheric origin is considered.
基金supported by National Natural Science Foundation of China (Grant No.10871101)the Research Fund for the Doctoral Program of Higher Education (Grant No. 20060055010)
文摘Let X and Y be real Banach spaces.Suppose that the subset sm[S1(X)] of the smooth points of the unit sphere [S1(X)] is dense in S1(X).If T0 is a surjective 1-Lipschitz mapping between two unit spheres,then,under some condition,T0 can be extended to a linear isometry on the whole space.
基金the Natural Science Foundation of the Education Department of Jiangsu Province (No.06KJD110092)
文摘Let T be a mapping from the unit sphere S[l^p（Г）] into S[l^p（△）] of two atomic AL^p- spaces. We prove that if T is a 1-Lipschitz mapping such that -T[S[l^p（Г）]] belong to T[S[l^p（Г）]], then T can be linearly isometrically extended to the whole space for p 〉 2; if T is injective and the inverse mapping T^-1 is a 1-Lipschitz mapping, then T can be extended to be a linear isometry from l^p（Г） into l^p（△） for 1 〈 p ≤ 2.
基金the National Natural Science Foundation of China (21073053,21073052 and 20773034)the Natural Science Foundation of Hebei Province (B2012205022)
文摘This paper describes syntheses and structure determination of four lanthanide complexes [Nd(2-Cl-4-FBA) 3 phen] 2 (1, 2-Cl-4-FBA = 2-chloro-4-fluorobenzoate, phen = 1,10-phenanthroline), [Ln(2,5-DClBA) 3 phen] 2 (Ln = Sm(2) and Tb(3), 2,5-DClBA = 2,5-dichlorobenzoate) and [Sm(2-Cl-4,5-DFBA) 3 (phen)(H 2 O)] 2 (4, (2-Cl-4,5-DFBA = 2-chloro-4,5-difluorobenzo- ate). The complexes were characterized by elemental analysis, infrared and ultraviolet spectra, and X-ray single-crystal diffraction. In the molecular structures of 1 4, two Ln 3+ ions are linked by four carboxyl groups, with two of them in a bridging bidentate mode and the other two in a bridging-chelating tridentate mode, forming four binuclear molecules. In addition, each Ln 3+ ion is also chelated to one phen molecule and one carboxyl group in the complexes, except each Sm 3+ ion in 4 which is bonded to one carboxyl group by unidentate mode and one H 2 O molecule. There are two different coordination polyhedrons for each Nd 3+ ion in the two similar molecular structures of 1 and they are a distorted monocapped square antiprismatic and a distorted tricapped triangular prism conformation, respectively. The coordination polyhedron for each Ln 3+ ion in 2 4 is a nine-coordinated distorted mono-capped square antiprismatic conformation. The complex 3 exhibits green luminescence under the radiation of UV light. The thermal decomposition behaviors of the complexes have been discussed by simultaneous TG/DSC-FTIR technique. The 3D surface graphs for the FTIR spectra of the evolved gases were recorded and the gaseous products were identified by the typical IR spectra obtained at different temperatures from the 3D surface graphs. Meanwhile, we discussed the nonisothermal kinetics of 1 4 by the integral isoconversional non-linear (NL-INT) method.
