The ZrNiH3 compound is a good candidate for hydrogen storage. In this work we used the first-principles calculation to study this compound. The crystal structures, the electronic properties and the optimization of the internal parameters are treated by the FP-LAPW method implanted in the WIEN2K code. The enthalpies of the dehydrogenation of the ZrNiH3 compound are calculated. We found that the enthalpy is about −42.89 kJ/mol H, greater but similar to the experimental value of −34.3 kJ/mol H. Potential reasons for this discrepancy are discussed. 相似文献
Al-doped ZnO (AZO) thin film, which possess the advantages of low cost, low sheet resistance and high transmittance, are one of the most promising candidates to replace indium tin oxide films as the transparent electrode. However, oxidation causes a substantial increase in the sheet resistance of AZO film after exposing in ambient and especially, damp heat environment. In this work, we compare structural, optical, electrical properties and environmental stability between films prepared by two different methods: sol–gel and rf sputtering. Experimental results indicate that the properties of film can be affected by different deposition method. From the X-ray diffraction analysis, all films have hexagonal wurtzite crystal structure with different preferable orientation in two different methods. Optical transmittance spectra of the AZO films exhibited transparency higher than about 80 % within the visible wavelength region and the optical band gap (Eg) of these films was increased in sputtered film, probably due to the increase of carrier concentration. The better environmental stability was found in AZO film prepared by sputtering method. Improved surface morphology and enhancement of crystal orientation (110) was considered for this improvement. 相似文献
Organic wastes were successfully used as soil amendment to improve agrosystems productivity. Yet, the effectiveness of this practice to enhance plant antioxidant capacities has received little attention. Here, we assess the effect of municipal solid waste (MSW) compost (at 40 t ha(-1)) on growth, polyphenol contents and antioxidant activities of Mesembryanthemum edule. MSW compost application significantly increased the soil contents of carbon, nitrogen, calcium, phosphorus and potassium. This was associated with higher nutrient (N, P, and K) uptake, which likely led to the significant improvement of the plant biomass and relative growth rate (RGR) (+93% on average) as compared to the control. In the same way, the fertilizing effect of the added organic matter significantly enhanced the antioxidant potential M. edule, assessed by radical scavenging activity, iron reducing power and β-carotene bleaching capacity. This was associated with significantly higher antioxidant contents, mainly total phenols and flavonoids. Heavy metal (Pb, Cd, Cu, and Zn) concentrations were slightly increased upon compost application, but remained lower than phytotoxic values. Overall, our results point out that short-term MSW compost application at 40 t ha(-1) is efficient in enhancing the productivity together with the antioxidant potentiality of M. edule without any adverse environmental impact. 相似文献
The chemical durability of some selected glass-ceramic materials based on the Li2O- (MnO, CaO)MgO---Al2O3---SiO2 glass composition, has been determined by HCl, using the powder test.
The leachability of the glass-ceramic was gradually increased by replacing MgO with MnO, while it was decreased by addition of MnO instead of CaO. Calcium oxide had a retarding effect on the durability of the material when it was added instead of MgO and/or MnO. However, on the addition of Al2O3 in replacing Li2O, the durability of the material was markedly improved. The leaching data were found to be dependent mainly on the proportion of the glass oxide constituents i.e. MgO/MnO, CaO/MnO and Li2O/Al2O3 ratios present in the glasses.
The results were correlated to different views concerning the effect of various ions on the rate of interdiffusion between the crystalline-glass materials and leaching solution, the type, and proportions of the crystalline phases developed in glass-ceramics and residual glass phase. 相似文献
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated.
The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization.
The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN
copolymers and 0.02 and 3.82 for In/MMA copolymers and finally 0.152 and 1.20 for AN/MMA copolymers. The rate of terpolymerization
in bulk has been measured as well as the relationship between the monomer mixture composition and the obtained terpolymer
in order to construct the compositional triangle. Also the effect of initiator concentration on the rate of terpolymerization
was investigated. The activation energy of terpolymerization was determined. The terpolymers were characterized by spectral
and thermo-gravimetric analyses. The data indicates that polyindene improves the thermal stability of the prepared terpolymers. 相似文献
Journal of Materials Science: Materials in Electronics - Herein, Cu ions surface-doped Dy2O3 photocatalyst (Cu–Dy2O3) is synthesized utilizing hydrothermal technique to degrade methyl violet... 相似文献
This present study was carried out to evaluate the effects of gamma irradiation on the fatty acids (FA) and mureins composition of two different radiotolerant bacteria. Bacillus cereus LSPQ 2872 and Salmonella Typhi ATCC 19430 were used for this study. The bacterial strains were treated with a sublethal radiation dose of 1 kGy to cause a cellular damage. Gas chromatography (GC) and high performance liquid chromatography (HPLC) analysis were performed to demonstrate respectively the modification of the FA composition and the changes in muropeptide profile. Results obtained show, for both bacteria, that this treatment had a significant effect (P ≤ 0.05) on the FA content with an increase of unsaturated FA percentage. Substantial changes were also noticed for the relative percentage and the number of the muropeptides. This study represents one of the few to demonstrate the modifications on bacterial membrane as a cellular response to survive the ionising radiation stress. 相似文献
The eutectic alloy Sn99.3-xCu0.7Agx has been examined as one of the lead free solder alloys. Melting point, electrical resistivity, internal friction, elastic
moduli, microhardness and the microstructure of the Sn99.3Cu0.7, Sn95.8Cu0.7Ag3.5 and Sn95.3Cu0.7Ag4 rapidly solidified lead free solder alloys have been investigated. The examined physical properties are improved by increasing
silver contents in the studied lead free solder alloys. These improved properties indicate that these alloys are adequate
for low temperature soldering applications. 相似文献
A single crystal structure determination of the complex (C5H9N3)CuCl4 [henceforth I] has been carried out. It crystallizes in the orthorhombic space group Cmca, with the cell parameters a=6.7053(5) Å, b=22.4171(19) Å, c=13.4173(9) Å, V=2016.8(3) Å3, and Z=8. In the complex, the anion is comprised of infinite zigzag chains of monochloro-bridged $\mathrm{CuCl}_{4}^{2-}$ units ?–CuCl3–μ–Cl–CuCl3–μ–Cl–CuCl3–? surrounded by the pyridinium-ammonium cations. The Cu ions are five-coordinate to chloride ions in a distorted square-pyramidal geometry with the zigzag chains formed by corner-sharing polyhedra. The Cu ion is located 0.151 Å above the basal plane. In the crystal, there are four intermolecular hydrogen bonding interactions, linking the CuCl chains to the cations to form a 2D-network. The resulting 2D-networks are further linked by aryl?aryl (π?π) interactions within the cationic chains leading to a 3D-network. Variable temperature magnetic susceptibility data were fit to a one-dimensional S=1/2 antiferromagnetic chain model yielding C=0.44(1) emu-K/mol-Oe and J=?37(1) K. 相似文献