The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD m...The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD method. The results show that the presence of RE atoms diffused into surface layer leads to an increase of phase structure factor, which explains the catalyzing and micro-alloying effects of RE.展开更多
The catalytic effects of the organic compounds of iron,tin and manganese on the degradation of low density polyethylene (LDPE) at compost temperature are discussed.A series of samples were aged in a simulating compost...The catalytic effects of the organic compounds of iron,tin and manganese on the degradation of low density polyethylene (LDPE) at compost temperature are discussed.A series of samples were aged in a simulating compost environment.The mechanical properties,viscosity average molecular weight (M η) of PE and hydroperoxide (POOH) concentration in the samples were measured.FT IR and DSC were also applied to characterize some samples.It was shown that the above mentioned metallic organic compounds can catalyze the degradation of LDPE efficiently.After 2 months aging,all samples with catalysts became fragile and the M η of the material decreased dramatically.Furthermore,the concentration of carbonyl and the degree of crystallinity of the material increased with the aging time.展开更多
The mixed-valence isopolyanion Mo6O193- was investigated by means of cyclic voltammographic, in-situ FTIR and UV-Visible-Near-IR spectro-electrochemicalmethods in aprotic media. The experimental results indicate that ...The mixed-valence isopolyanion Mo6O193- was investigated by means of cyclic voltammographic, in-situ FTIR and UV-Visible-Near-IR spectro-electrochemicalmethods in aprotic media. The experimental results indicate that the Mo6O193-was formed whereafter Mo6O193- was reduced, (E0' = - 0. 690 V, n = 1 ). The characteristic absorptions of Mo6O193- are 500 nm, 900 nm and 1100 nm in UV-VisibleNear-IR spectrum and 940 cm-1 in IR spectrum.展开更多
The ternary CoCl2-FeCl3 graphite intercalation compounds (CoCl2-FeCl3 G/C) have been subjected to different treatments in various media. It is found that the CoCl2-FeCl3 GIC is stable 'when it is stored under cond...The ternary CoCl2-FeCl3 graphite intercalation compounds (CoCl2-FeCl3 G/C) have been subjected to different treatments in various media. It is found that the CoCl2-FeCl3 GIC is stable 'when it is stored under conditions of opening to at-mosphere,whereas,acids,NaOH,boiling water,and heat treat-ments have different effects on the stability of the CoCl2-FeCl3 G/C.展开更多
The distribution of trivalent and tetravalent cations in several ATxV6-xO11 compounds was quantitatively studied by the bond valence method. In SrV6O11, the M(3) sites were mainly occupied by trivaient cations; while ...The distribution of trivalent and tetravalent cations in several ATxV6-xO11 compounds was quantitatively studied by the bond valence method. In SrV6O11, the M(3) sites were mainly occupied by trivaient cations; while M(1) and M(2) sites were shared by trivalent and tetravalent cations, the relative content of tetravalent at M(1) sites was higher than at M(2) sites. During substitution process, the trivalent cations preferred to occupy M(3) sites, tetravalent ones preferred to occupy M(2) sites. The occupancy of trivalent and tetravalent cations at M sites would change with the substitution展开更多
A novel inorganic-organic hybrid compound, {[Co（dien）]4[0aO4）MoV8（wV10.56MoV10.44）4- O33（OH）3]}＇nH20 （1, n = 1, dien = diethylenetriamine）, has been synthesized hydrothermally and characterized by single-cry...A novel inorganic-organic hybrid compound, {[Co（dien）]4[0aO4）MoV8（wV10.56MoV10.44）4- O33（OH）3]}＇nH20 （1, n = 1, dien = diethylenetriamine）, has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system with a = 11.927（2）, b = 13.328（3）, c = 19.306（4）A, a = 93.76（3）, β = 94.14（3）, γ = 109.99（3）°, V= 2863.2（12） A3, space group P1 and Z = 2 at 173 K. The final full-matrix least-squares refinement converged to R = 0.049 for 9621 observed reflections with 1 〉 2σ（I） and wR = 0.139 for all data （9871） and S = 1.073. Crystal structure analysis shows that 1 contains a kind of the first reported mixed-valence and molybdenum-tungsten mixed-distributed e-Keggin structural polyanion capped by four Co（dien） fragments with the main group element P occupying the center site. These results were further confirmed by energy-dispersive X-ray spectroscopy （EDS）, X-ray powder diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, Raman spectroscopy, Thermogravimetry （TG） and X-ray photoelectron spectroscopy （XPS） analyses.展开更多
The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterizati...The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.展开更多
Ⅰ. INTRODUCTION Alloy TiAl with LI_o structure has been of interest for its low density, high strength, corrosion and oxidation resistance, especially the anomalous yield strength dependent on temperature. However, i...Ⅰ. INTRODUCTION Alloy TiAl with LI_o structure has been of interest for its low density, high strength, corrosion and oxidation resistance, especially the anomalous yield strength dependent on temperature. However, its embrittlement at room temperature limits its application. Despite that manifold origins affect brittleness of some alloys, especially intermetallic compounds, it展开更多
基金support from the key laboratory foundation of precision hot forming for national defense science and technology.
文摘The valence electron structure (VES) in compound layer of steel plasma-nitrided at 560°C with rare earth (RE) addition was calculated based on the empirical electron theory (EET) of solids and molecules and BLD method. The results show that the presence of RE atoms diffused into surface layer leads to an increase of phase structure factor, which explains the catalyzing and micro-alloying effects of RE.
文摘The catalytic effects of the organic compounds of iron,tin and manganese on the degradation of low density polyethylene (LDPE) at compost temperature are discussed.A series of samples were aged in a simulating compost environment.The mechanical properties,viscosity average molecular weight (M η) of PE and hydroperoxide (POOH) concentration in the samples were measured.FT IR and DSC were also applied to characterize some samples.It was shown that the above mentioned metallic organic compounds can catalyze the degradation of LDPE efficiently.After 2 months aging,all samples with catalysts became fragile and the M η of the material decreased dramatically.Furthermore,the concentration of carbonyl and the degree of crystallinity of the material increased with the aging time.
文摘The mixed-valence isopolyanion Mo6O193- was investigated by means of cyclic voltammographic, in-situ FTIR and UV-Visible-Near-IR spectro-electrochemicalmethods in aprotic media. The experimental results indicate that the Mo6O193-was formed whereafter Mo6O193- was reduced, (E0' = - 0. 690 V, n = 1 ). The characteristic absorptions of Mo6O193- are 500 nm, 900 nm and 1100 nm in UV-VisibleNear-IR spectrum and 940 cm-1 in IR spectrum.
文摘The ternary CoCl2-FeCl3 graphite intercalation compounds (CoCl2-FeCl3 G/C) have been subjected to different treatments in various media. It is found that the CoCl2-FeCl3 GIC is stable 'when it is stored under conditions of opening to at-mosphere,whereas,acids,NaOH,boiling water,and heat treat-ments have different effects on the stability of the CoCl2-FeCl3 G/C.
文摘The distribution of trivalent and tetravalent cations in several ATxV6-xO11 compounds was quantitatively studied by the bond valence method. In SrV6O11, the M(3) sites were mainly occupied by trivaient cations; while M(1) and M(2) sites were shared by trivalent and tetravalent cations, the relative content of tetravalent at M(1) sites was higher than at M(2) sites. During substitution process, the trivalent cations preferred to occupy M(3) sites, tetravalent ones preferred to occupy M(2) sites. The occupancy of trivalent and tetravalent cations at M sites would change with the substitution
基金Foundation of Education Department of Fujian Province(Nos.JA11245 and JB12199)National Natural Science Foundation of China(No.40972035)
文摘A novel inorganic-organic hybrid compound, {[Co（dien）]4[0aO4）MoV8（wV10.56MoV10.44）4- O33（OH）3]}＇nH20 （1, n = 1, dien = diethylenetriamine）, has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system with a = 11.927（2）, b = 13.328（3）, c = 19.306（4）A, a = 93.76（3）, β = 94.14（3）, γ = 109.99（3）°, V= 2863.2（12） A3, space group P1 and Z = 2 at 173 K. The final full-matrix least-squares refinement converged to R = 0.049 for 9621 observed reflections with 1 〉 2σ（I） and wR = 0.139 for all data （9871） and S = 1.073. Crystal structure analysis shows that 1 contains a kind of the first reported mixed-valence and molybdenum-tungsten mixed-distributed e-Keggin structural polyanion capped by four Co（dien） fragments with the main group element P occupying the center site. These results were further confirmed by energy-dispersive X-ray spectroscopy （EDS）, X-ray powder diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, Raman spectroscopy, Thermogravimetry （TG） and X-ray photoelectron spectroscopy （XPS） analyses.
基金supported by the National Natural Science Foundation of China (21975032 and 21571020)the National Key Research and Development Program of China (2018YFA0702100)
文摘The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.
基金Project supported by the National Advanced Materials Committee
文摘Ⅰ. INTRODUCTION Alloy TiAl with LI_o structure has been of interest for its low density, high strength, corrosion and oxidation resistance, especially the anomalous yield strength dependent on temperature. However, its embrittlement at room temperature limits its application. Despite that manifold origins affect brittleness of some alloys, especially intermetallic compounds, it
