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61.
微波-气相-热压法分解高纯铂的研究 总被引:1,自引:0,他引:1
本文研究了微波气相热压法新技术分解高纯铂在密闭的聚四氟乙烯高压罐中,以微波瞬间加热混合酸产生的高压、纯净蒸气分解金属铂,此法避免了酸中杂质的沾污以制备供高纯铂分析的试液,提高了痕量杂质分析的准确度和降低检测限 相似文献
62.
Yan-Ping Yuan De-Yuan Kong Abraham Clearfield 《Journal of solid state chemistry》2005,178(6):2030-2035
The first organically templated 3d-4f mixed metal sulfates, [H2en]2{La2M(SO4)6(H2O)2} (M=Co 1, Ni 2) have been synthesized and structurally determined from non-merohedrally twinned crystals. The two compounds are isostructural and their structures feature a three-dimensional anionic network formed by the lanthanum(III) and nickel(II) ions bridged by sulfate anions. The La(III) ions in both compounds are 10-coordinated by four sulfate anions in bidentate chelating fashion, and two sulfate anions in a unidentate fashion. The transition metal(II) ion is octahedrally coordinated by six oxygens from four sulfate anions and two aqua ligands. The doubly protonated enthylenediamine cations are located at the tunnels formed by 8-membered rings (four La and four sulfate anions). 相似文献
63.
以乙醇为溶剂, 钛酸四丁酯为前驱体, 用溶剂热法制备了Ag表面修饰的负载型纳米二氧化钛光催化剂. 利用X射线衍射(XRD)、N2吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外-可见(UV-Vis)光谱等技术对其进行了系统的表征, 以亚甲基蓝(MB)溶液的脱色降解为模型反应, 考察了不同Ag含量样品的光催化性能. 结果表明: 用溶剂热法制备的样品中TiO2皆为锐钛矿相, 金属Ag颗粒沉积在TiO2表面, 粒径为2 nm左右, 比表面积较溶胶凝胶法制备的样品大大增加, 最高可达151.44 m2·g-1; UV-Vis光谱和光催化实验表明: Ag修饰使TiO2对光的吸收能力大大增强, 吸收带边红移至可见光区, 亚甲基蓝在该复合材料上的光催化降解反应遵循一级反应动力学模型; 溶剂热法制备样品的光催化性能明显好于溶胶凝胶法制备的样品, 在紫外光和可见光下, Ag摩尔分数为5%的样品表现出最佳的光催化活性. 相似文献
64.
Polycrystalline Cu3P was successfully prepared under a wide variety of solvothermal conditions. The reaction of red phosphorus with several copper sources (copper metal, copper (I) iodide, copper (I) chloride and copper (II) chloride) at 150-200 °C for 1-2 days in water produced Cu3P. Products were examined with powder X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Thermal analyses and optical spectroscopy were also performed. A detailed list of reaction conditions, products and impurity phases (where applicable) are reported. 相似文献
65.
Summary Recently much attention has been directed to the validation of analytical methods. The level of validation will depend on the method application. If a method is developed for general use, for instance by different analysts, instruments or laboratories, then the effect of these changes need evaluation. This is normally referred to as ruggedness testing, where the limitations of the method to changes in the specified conditions are examined.This paper examines the use of Plackett-Burman fractional factorial experiment designs for ruggedness testing in high performance liquid chromatography (HPLC). The ability of these designs to identify confounding effects is applied to the stability indicating analysis of Salbutamol and its major degradation product, AH4045. The results show that confounding effects, proving extremely pertinent to HPLC, can be identified.The assay proved rugged to most tested changes although not to the use of column packing material from different manufacturers. 相似文献
66.
The two new compounds [Fe(tren)]FeSbS4 ( 1 ) (tren = tris(2‐aminoethyl)amine) and [Fe(dien)2]Fe2Sb4S10 ( 2 ) (dien = diethylendiamine) were prepared under solvothermal conditions and represent the first thioantimonates(III) with iron cations integrated into the anionic network. In both compounds Fe3+ is part of a [2FeIII‐2S] cluster which is often found in ferredoxines. In addition, Fe2+ ions are present which are surrounded by the organic ligands. In ( 1 ) the Fe2+ ion is also part of the thioantimonate(III) network whereas in ( 2 ) the Fe2+ ion is isolated. In both compounds the primary SbS3 units are interconnected into one‐dimensional chains. The mixed‐valent character of [Fe(tren)]FeSbS4 was unambiguously determined with Mössbauer spectroscopy. Both compounds exhibit paramagnetic behaviour and for ( 1 ) a deviation from linearity is observed due to a strong zero‐field splitting. Both compounds decompose in one single step. 相似文献
67.
The longitudinal motions and vertical accelerations of a floating torus as well as wave motion inside the torus are studied by model tests in regular deep-water waves. Comparisons are made with linear and partly with second-order potential-flow theory for the smallest examined experimental wave height-to-wave length ratio 1/120. Reasonable agreement is obtained, in particular for the linear problem. The importance of 3D flow, hydroelasticity and strong hydrodynamic frequency dependency is documented. Experimental precision errors and bias errors, for instance, due to tank-wall interference are discussed. Numerical errors due to viscous effects are found to be secondary. Experiments show that the third and fourth harmonic accelerations of the torus matter and cannot be explained by a perturbation method with the wave steepness as a small parameter. 相似文献
68.
Peter E.J. Vos Claes Eskilsson Alessandro Bolis Sehun Chun Robert M. Kirby 《International Journal of Computational Fluid Dynamics》2013,27(3):107-125
Time-stepping algorithms and their implementations are a critical component within the solution of time-dependent partial differential equations (PDEs). In this article, we present a generic framework – both in terms of algorithms and implementations – that allows an almost seamless switch between various explicit, implicit and implicit–explicit (IMEX) time-stepping methods. We put particular emphasis on how to incorporate time-dependent boundary conditions, an issue that goes beyond classical ODE theory but which plays an important role in the time-stepping of the PDEs arising in computational fluid dynamics. Our algorithm is based upon J.C. Butcher's unifying concept of general linear methods that we have extended to accommodate the family of IMEX schemes that are often used in engineering practice. In the article, we discuss design considerations and present an object-oriented implementation. Finally, we illustrate the use of the framework by applications to a model problem as well as to more complex fluid problems. 相似文献
69.
Wei Jiang Zheng-Long Yang Ding Weng Jun-Wei Wangb Yun-Feng Lu Min-Juan Zhang Zhen-Zhong Yang 《中国化学快报》2014,25(6):849-853
PbTe/SnTe hybrid nanocrystals with designed shape, chemical composition and narrow size distribution were synthesized by an efficient solvothermal approach. This approach enables mass and economical synthesis of PbTe-based nanocrystals. The organic ligands were completely removed by pretreatment with a super-hydride solution, making it possible to fabricate fully dense and robust thermoelectric devices with increased electrical conductivity. 相似文献
70.
Qing-Long Bai Chun-Hua Zhang Juan-Juan Song Jing-Hai Liu Yan-Chun Feng Li-Mei Duan Chuan-Hui Cheng 《中国化学快报》2016,27(5):764-768
A metal-free purple H2Pc single crystal was synthesized by a facile solvothermal method, and its solubility and near-infrared (NIR) optical properties were also investigated due to its potential applications as a light-emitting layer for OLEDs. The H2Pc single crystal is insoluble in 1-chlorine naphthalene and other organic solvents. It gives a wide absorption in the range from 620 nm to 679 nm and a wide emission in near 922 nm. As an active light-emitting layer, H2Pc was employed to fabricate electroluminescent (EL) devices with a structure of ITO/NPB (30 nm)/Alq3:H2Pc (30 nm)/BCP (20 nm)/Alq3 (20 nm)/Al. The emission center is at 936 nm when the H2Pc doping concentration is 20 wt%. The doping concentration strongly governs the emission intensity. When doping concentration decreases from 10 wt% to 1 wt%, the emission intensity remarkably fades, and simultaneously the emission center undergoes a blue shift. 相似文献