Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was take...Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was taken to research the floatability from the perspective of crystal chemistry.And contact angle test and reagent adsorption test were used to support the simulation results.In addition,the weighted total density of broken bonds is proposed for the first time to judge the generation probability of cleavage surface.The DFT calculation results display that the Na and Al sites on the albite surface are the adsorption sites of water molecules.While the water molecules only bond with Al atom on the surface of spodumene and each Al site can adsorb only one water molecule.Thus,the wetting effect of water molecules on the albite surface is stronger than that of spodumene.This is consistent with the result of contact angle.In sodium oleate system,the oleic acid anion is adsorbed on the spodumene surface in form of a multicomponent ring while the albite is a single ring.Theoretically,oleic acid anion can be strongly adsorbed on the surface of spodumene and albite under vacuum.The adsorption strength of spodumene is higher than that of albite.However,on hydrated surface,the adsorption strength of oleic acid anion on mineral surface is greatly reduced due to the interaction between water molecules and metal site on mineral surface.Thus,spodumene and albite are hard to float without external activated ions in sodium oleate system.展开更多
The density,function and discrete variation method (DFT - DVM) is used to study the interaction between kaolinite and gold. The correlation among the structure, chemical bond and stability is discussed. Several models...The density,function and discrete variation method (DFT - DVM) is used to study the interaction between kaolinite and gold. The correlation among the structure, chemical bond and stability is discussed. Several models are selected without gold and with gold in different directions and sites. The results show that the models with gold on the edge of kaolinite basal layer are more stable than those with gold above or under the layer, the models with gold near to [AlO2 (OH)(4)] octahedra are more stable than those with gold near to the vacancy without aluminium. The interaction between gold and the surface ions of kaolinite is strong enough to form the surface complexes.展开更多
Using the air plasma ignition technique, physicochemical process of burning can be accelerated; concentration limit ofretrofires both can be extended; reliability of retrofires and stability of burning can be improved...Using the air plasma ignition technique, physicochemical process of burning can be accelerated; concentration limit ofretrofires both can be extended; reliability of retrofires and stability of burning can be improved. In this paper, using internalequivalent heat area in place of electric are that created Ohm heat, the flow fields of thermodynamic equilibrium chemistry con-gealment and chemistry non-equilibrium in the plasma generator were simulated. The influences of the inlet prerotation angleof air, the inlet total pressure of air and the airflow compression angle of spray nozzle on the temperature on the surface of elec-展开更多
It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by co...It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization, of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.展开更多
The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-...The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-xSbxTe32(x = 0,2,6,8,12,14,18 and 20) were calculated. The results show that there is less difference in the ionic bonds between Te( I)-Bi(Sb) and Te(Ⅱ)-Bi(Sb) , but the covalent bond of Te(Ⅰ)-Bi( Sb ) is stronger than that of Te(Ⅱ)-Bi( Sb ) . The interaction between Te(Ⅰ) and Te(Ⅰ) in different layers is the weakest and the interaction should be Van Der Wools power. The charge of Sb is lower than that of Bi, and the ionic bond of Te-Sb is weaker than that of Te-Bi. The covalent bond of Te-Sb is also weaker than that of Te-Bi. Therefore, the thermoelectric property may be imfiroved by adjusting the electrical conductivity and thermal conductivity through changing the composition in the compounds of Bi-Sb-Te. The calculated results are consistent with the experiments.展开更多
The complexes of rare earth trifluoroacetate with two 1, 10-phenanthroline Ln (CF_3COO)_3 ·(Phen )_2· CH_3COCH_3·3H_2O (Ln=La, Pr, Nd, Sm, Eu) have prepared in the mixed slovents of H_2O and CH_3COCH_3,...The complexes of rare earth trifluoroacetate with two 1, 10-phenanthroline Ln (CF_3COO)_3 ·(Phen )_2· CH_3COCH_3·3H_2O (Ln=La, Pr, Nd, Sm, Eu) have prepared in the mixed slovents of H_2O and CH_3COCH_3, and the single crystal Nd (CF_3COO)_3· (Phen )_2· CH_3COCH_3· 3H_2O was determined by four-circle X-ray diffractometer. The crystal is a monoclinic system with space group P2_1/n(14# ), a=0. 9253 ( 1 )nm , b=2. 1500 ( 2 ) nm , c=1.8981 ( 4 ) nm, β= 95. 28( 1 )°, V=3.760(8) nm￣3 , Z=4 , R=0. 035. The coordination number of Nd is 9 , and the coordination polyhedron of Nd atom is distorted tricapped triagonal prism. The electronic structures and chemical bonds of the complex Nd (CF_3COO)_3· (Phen )_2· CH_3COCH_3·3H_2O is studied by the spin unrestricted INDO method.展开更多
Oxygen and nitrogen adsorption in single walled carbon nanotube (SWCNT) is studied by density function and discrete variational (DFT-DVM) method.The models of O 2 and N 2 adsorption in the SWCNT are optimized based...Oxygen and nitrogen adsorption in single walled carbon nanotube (SWCNT) is studied by density function and discrete variational (DFT-DVM) method.The models of O 2 and N 2 adsorption in the SWCNT are optimized based on the energy minimization.The calculated results of density of state,populations and energy gaps of the molecular orbitals show that oxygen adsorption in SWCNT increases the carbon nanotube`s electrical conductivity more notably than nitrogen adsorption,which is consistent with the experiment.展开更多
The structure, chemical bonds and hydra-tion activity of C12A were studied by SCC-DV-Xa method of computational quantum chemistry. The calculated results show that Ca-O bond will be first broken off when C12A hydrates...The structure, chemical bonds and hydra-tion activity of C12A were studied by SCC-DV-Xa method of computational quantum chemistry. The calculated results show that Ca-O bond will be first broken off when C12A hydrates, the reactivity of Al(2)O4 tetrahedron is superior to that of Al(1)O4 tet, thedron and the rupture of the Al-O-Al chain composed of two types of AlO4 tetrahedra under the action of water lies in the very weak Al(2)-O(2) bonds. the Al-O bond strength of C12A7 is between C3A and C11A7·CaF2.展开更多
Hexaacetyl D-mannose hydrazine is one type of important intermediates in saccharide chemistry. In this paper, its single crystal was obtained and furthermore, X-ray diffraction and quantum chemistry calculation were p...Hexaacetyl D-mannose hydrazine is one type of important intermediates in saccharide chemistry. In this paper, its single crystal was obtained and furthermore, X-ray diffraction and quantum chemistry calculation were performed. It belongs to orthorhombic system, space group P212121, with a=16.267（3）, b=19.263（3）, c=7.1948（12）A, Mr=446.41, Dc=1.315 g/cm^3, V=2254.5（6）A^3 and Z=4. Meanwhile, the experimental results also provide information for designing a kind of molecular switch based on the mannose nitrogenous derivatives.展开更多
A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental a...A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental analysis and IR spectra. The crystal belongs to triclinic,space group P1 with a = 7.8043（7）,b = 10.4069（9）,c = 14.3658（13） ,α = 105.3170（10）,β = 96.877（2）,γ = 96.7580（10）o,V = 1103.56（17） 3,Mr = 539.96,Z = 2,Dc = 1.625 g/cm3,μ = 1.050 mm-1,F（000） = 550,the final R = 0.0324 and wR = 0.0952. In the crystal,the structure consists of discrete molecules containing a five-coordinate copper（Ⅱ ） in a distorted square pyramidal configuration. Intramolecular O-H···O hydrogen bonds,weak intermolecular C-H···O hydrogen bonds and π-π stacking link the molecules into a one-dimensional chain structure. The study on the title complex has been performed with quantum chemistry calculation by means of G03W package on the Lanl2dz basis set. The stabilities of the complex together with the orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.展开更多
The free-radical growth mechanisms for the formation of polycyclic arenes (PCAs) were constructed based on the block unit of benzene, and were calculated by the quantum chemistry PM3 method. Two kinds of reaction path...The free-radical growth mechanisms for the formation of polycyclic arenes (PCAs) were constructed based on the block unit of benzene, and were calculated by the quantum chemistry PM3 method. Two kinds of reaction paths are proposed and discussed. The calculation results show that the formation of PCAs is only controlled by the elimination of H atom from benzene, and the corresponding activation energy is 307.60 kJ·mol-1. H2 is only the ef-fluent gas in our proposed reaction mechanism, and the calculation results are in accord with the experimental facts.展开更多
基金supported by the National Natural Science Foundation of China(No.52064017)Key Research and Development Project of Jiangxi Province(No.20181BBG70050)+2 种基金Natural Science Foundation of Jiangxi Province(No.20202BABL204034)Science and Technology Research Project of Education Department of Jiangxi Province(No.GJJ190425)the Youth Jinggang Scholars Program in Jiangxi Province,and Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology.
文摘Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was taken to research the floatability from the perspective of crystal chemistry.And contact angle test and reagent adsorption test were used to support the simulation results.In addition,the weighted total density of broken bonds is proposed for the first time to judge the generation probability of cleavage surface.The DFT calculation results display that the Na and Al sites on the albite surface are the adsorption sites of water molecules.While the water molecules only bond with Al atom on the surface of spodumene and each Al site can adsorb only one water molecule.Thus,the wetting effect of water molecules on the albite surface is stronger than that of spodumene.This is consistent with the result of contact angle.In sodium oleate system,the oleic acid anion is adsorbed on the spodumene surface in form of a multicomponent ring while the albite is a single ring.Theoretically,oleic acid anion can be strongly adsorbed on the surface of spodumene and albite under vacuum.The adsorption strength of spodumene is higher than that of albite.However,on hydrated surface,the adsorption strength of oleic acid anion on mineral surface is greatly reduced due to the interaction between water molecules and metal site on mineral surface.Thus,spodumene and albite are hard to float without external activated ions in sodium oleate system.
基金Supported by the Natural Science Foundation of China (No. 49802003)
文摘The density,function and discrete variation method (DFT - DVM) is used to study the interaction between kaolinite and gold. The correlation among the structure, chemical bond and stability is discussed. Several models are selected without gold and with gold in different directions and sites. The results show that the models with gold on the edge of kaolinite basal layer are more stable than those with gold above or under the layer, the models with gold near to [AlO2 (OH)(4)] octahedra are more stable than those with gold near to the vacancy without aluminium. The interaction between gold and the surface ions of kaolinite is strong enough to form the surface complexes.
文摘Using the air plasma ignition technique, physicochemical process of burning can be accelerated; concentration limit ofretrofires both can be extended; reliability of retrofires and stability of burning can be improved. In this paper, using internalequivalent heat area in place of electric are that created Ohm heat, the flow fields of thermodynamic equilibrium chemistry con-gealment and chemistry non-equilibrium in the plasma generator were simulated. The influences of the inlet prerotation angleof air, the inlet total pressure of air and the airflow compression angle of spray nozzle on the temperature on the surface of elec-
基金Funded by the Natural Science Fourdation of China(Project 59972018)
文摘It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization, of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.
基金Funded by Open Foundation of State Key Laboratory of Ad-vanced Technology for Materials Synthesis and Processing, Wuhan University of Technology.
文摘The density junction theory and discrete variation method ( DFT - DVM) was used to study correlation between composition, structure, chemical bond, and property of thermoelectrics of Bi-Sb-Te series. 8 models of Bi20-xSbxTe32(x = 0,2,6,8,12,14,18 and 20) were calculated. The results show that there is less difference in the ionic bonds between Te( I)-Bi(Sb) and Te(Ⅱ)-Bi(Sb) , but the covalent bond of Te(Ⅰ)-Bi( Sb ) is stronger than that of Te(Ⅱ)-Bi( Sb ) . The interaction between Te(Ⅰ) and Te(Ⅰ) in different layers is the weakest and the interaction should be Van Der Wools power. The charge of Sb is lower than that of Bi, and the ionic bond of Te-Sb is weaker than that of Te-Bi. The covalent bond of Te-Sb is also weaker than that of Te-Bi. Therefore, the thermoelectric property may be imfiroved by adjusting the electrical conductivity and thermal conductivity through changing the composition in the compounds of Bi-Sb-Te. The calculated results are consistent with the experiments.
文摘The complexes of rare earth trifluoroacetate with two 1, 10-phenanthroline Ln (CF_3COO)_3 ·(Phen )_2· CH_3COCH_3·3H_2O (Ln=La, Pr, Nd, Sm, Eu) have prepared in the mixed slovents of H_2O and CH_3COCH_3, and the single crystal Nd (CF_3COO)_3· (Phen )_2· CH_3COCH_3· 3H_2O was determined by four-circle X-ray diffractometer. The crystal is a monoclinic system with space group P2_1/n(14# ), a=0. 9253 ( 1 )nm , b=2. 1500 ( 2 ) nm , c=1.8981 ( 4 ) nm, β= 95. 28( 1 )°, V=3.760(8) nm￣3 , Z=4 , R=0. 035. The coordination number of Nd is 9 , and the coordination polyhedron of Nd atom is distorted tricapped triagonal prism. The electronic structures and chemical bonds of the complex Nd (CF_3COO)_3· (Phen )_2· CH_3COCH_3·3H_2O is studied by the spin unrestricted INDO method.
文摘Oxygen and nitrogen adsorption in single walled carbon nanotube (SWCNT) is studied by density function and discrete variational (DFT-DVM) method.The models of O 2 and N 2 adsorption in the SWCNT are optimized based on the energy minimization.The calculated results of density of state,populations and energy gaps of the molecular orbitals show that oxygen adsorption in SWCNT increases the carbon nanotube`s electrical conductivity more notably than nitrogen adsorption,which is consistent with the experiment.
文摘The structure, chemical bonds and hydra-tion activity of C12A were studied by SCC-DV-Xa method of computational quantum chemistry. The calculated results show that Ca-O bond will be first broken off when C12A hydrates, the reactivity of Al(2)O4 tetrahedron is superior to that of Al(1)O4 tet, thedron and the rupture of the Al-O-Al chain composed of two types of AlO4 tetrahedra under the action of water lies in the very weak Al(2)-O(2) bonds. the Al-O bond strength of C12A7 is between C3A and C11A7·CaF2.
基金The project was supported by the National Natural Science Foundation of China (No. 20272031)
文摘Hexaacetyl D-mannose hydrazine is one type of important intermediates in saccharide chemistry. In this paper, its single crystal was obtained and furthermore, X-ray diffraction and quantum chemistry calculation were performed. It belongs to orthorhombic system, space group P212121, with a=16.267（3）, b=19.263（3）, c=7.1948（12）A, Mr=446.41, Dc=1.315 g/cm^3, V=2254.5（6）A^3 and Z=4. Meanwhile, the experimental results also provide information for designing a kind of molecular switch based on the mannose nitrogenous derivatives.
基金supported by the Postgraduate Foundation of Taishan University (No. Y07--2-16)
文摘A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental analysis and IR spectra. The crystal belongs to triclinic,space group P1 with a = 7.8043（7）,b = 10.4069（9）,c = 14.3658（13） ,α = 105.3170（10）,β = 96.877（2）,γ = 96.7580（10）o,V = 1103.56（17） 3,Mr = 539.96,Z = 2,Dc = 1.625 g/cm3,μ = 1.050 mm-1,F（000） = 550,the final R = 0.0324 and wR = 0.0952. In the crystal,the structure consists of discrete molecules containing a five-coordinate copper（Ⅱ ） in a distorted square pyramidal configuration. Intramolecular O-H···O hydrogen bonds,weak intermolecular C-H···O hydrogen bonds and π-π stacking link the molecules into a one-dimensional chain structure. The study on the title complex has been performed with quantum chemistry calculation by means of G03W package on the Lanl2dz basis set. The stabilities of the complex together with the orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.
基金Supported by the National Basic Research Program of China (2005CB221203)the National Natural Science Foundation of China (20576087, 20776093, 50534070)the Natural Science Foundation of Shanxi Province (2006011022, 2009021015)
文摘The free-radical growth mechanisms for the formation of polycyclic arenes (PCAs) were constructed based on the block unit of benzene, and were calculated by the quantum chemistry PM3 method. Two kinds of reaction paths are proposed and discussed. The calculation results show that the formation of PCAs is only controlled by the elimination of H atom from benzene, and the corresponding activation energy is 307.60 kJ·mol-1. H2 is only the ef-fluent gas in our proposed reaction mechanism, and the calculation results are in accord with the experimental facts.
