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971.
氟胺氰菊酯的定性定量分析 总被引:4,自引:0,他引:4
氟胺氰菊酯是一种用于蜜峰的高效杀螨剂。从20%商品氟胺氰菊酯粉剂中通过硅胶柱层板分离得到了96.6%的纯品并用FTIR和GC/MC进行定性量测定。采用GC/MS定量分析的方法,氟胺氰菊酯的浓度在0.05-10mg/L范围为线性响应,最低检测极限为 0.01mg/L。采用R(-)N-3,5-二硝基苯甲酰-苯基甘氨酸和长链烃的硅胶微粒手性柱,可成功地分离氟胺氰菊酯的二种旋光异构体,它们在商品氟胺氰菊酯中的比例近似为1:1。 相似文献
972.
New metal-carbon clusters, M4C9
+ (M = Ti, V), generated using a combined thermal arc discharge evaporation set-up, have been studied with quadrupole mass
spectrometry. Reactivities of these clusters have been investigated by means of association reactions with H2O. Metal-carbon clusters of other compositions have also been studied. We speculate on the mechanism of formation of larger
metal-carbon clusters. 相似文献
973.
974.
We consider a kinetic BGK model relaxing to isentropic gas dynamics previously introduced by the authors, but with Dirichlet boundary condition on the incoming velocities. We pass to the limit as the relaxation parameter tends to zero by compensated compactness inside the domain, and obtain that the limit satisfies entropy inequalities on the boundary involving weak traces of entropy fluxes. Our method is very general and could be applied to any entropy satisfying BGK model as soon as we have strong compactness of the macroscopic variables inside the domain. 相似文献
975.
Bao-Li An Jian-Xin ShiWai-Kwok Wong Kok-Wai CheahRong-Hua Li Yan-Sheng YangMeng-Lian Gong 《Journal of luminescence》2002,99(2):155-160
A novel organic ligand, 6-parachloroaniline carbonyl 2-pyridine carboxylic acid, and the corresponding europium complex, tris(6-parachloroaniline carbonyl-2-pyridine carboxylate) europium (III) have been designed and synthesized. The results showed that the synthesized product was a conjugated complex, emitting remarkable strong red luminescence, and was a good red luminescence material with good thermal stability. The 5D0 lifetime of Eu3+ in the complex was examined using time-resolved spectroscopic analysis. The lifetime values for 1.0×10−5 mol/l ethanol solution of the complex and for the complex solid were 0.49±0.01 and 1.94±0.01 ms, respectively. 相似文献
976.
Infrared spectroscopic characteristics and gas chromatographic retention indices of tri- and tetramethylcyclohexenyl butenyl ketones were determined at different temperatures of analysis. Thermodynamic characteristics of sorption on the apolar stationary phase were calculated. The sorption characteristics of tri- and tetramethylcyclohexenyl butenyl ketones show that under conditions of capillary gas chromatography these compounds are retained due to the dispersive energy. It was shown by FTIR spectroscopy that the formation of conjugation systems of double bonds is responsible for the higher retention of the -isomers compared with that of the -isomers. The shortening of the distance between the carbonyl and trimethylcyclohexenyl groups was found to be accompanied by a decrease in the retention of the isomeric compounds. 相似文献
977.
In the present record a model for the gas-phase reactions during the chemical vapor deposition (CVD) processes of group 13-15 materials is presented, based on the results of extensive quantum-chemical modeling. Thermodynamic criteria have been introduced to evaluate the importance of a range of association reactions. For the organometallic and hydride derivatives, association processes are found to be favorable both thermodynamically and kinetically. Formation of high mass association products takes place under CVD conditions, including laser-assisted CVD. Structural and thermodynamic properties of the most important ring and cluster intermediates have been predicted. The stoichiometry-controlled synthesis of the 13-15 ternary alloys and nanoparticles using cluster compounds as single-source precursors is predicted to be viable. The association pathway described may be generalized to the CVD reactions of many binary materials (12-16, 13-16, 13-15, 14-15, 14-16). 相似文献
978.
IntroductionRare earth phosphates have been widely studied due to their important properties and potential technological application. The early studies of cerium phosphates focused on their inter..esting ion exchange properties, and a series of such compounds was prepared['--']. Rare earthorthophosphates are also regarded as promising phosphors for fluorescent tubes because oftheir luminescence properties["']. Since crystal NdP,O,. was discovered to have efficient laseremi.sion[6'7), the pol… 相似文献
979.
Z. H. Mkhitaryan A. A. Shatveryan V. M. Aroutiounian F. V. Gasparyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2008,43(3):131-135
Low-frequency noise, in the range 1–500 Hz, is measured at room temperature in samples of Au/PS/SCS/Al structure with a layer of porous silicon. Numerical values of the Hooge parameter αH are estimated and the dependence of αH on the composition of the gaseous environment, where the sample is placed, is determined. Possible reasons of observed high values of αH for the samples in air and of the increase in αH in conditions of gas adsorption are discussed. Introducing of carbon oxide in air changes the shape of spectrum. 相似文献
980.
We consider particles in
d
, d2, interacting via attractive pair and repulsive four-body potentials of the Kac type. Perturbing about mean-field theory, valid when the interaction range becomes infinite, we prove rigorously the existence of a liquid–gas phase transition when the interaction range is finite but long compared to the interparticle spacing for a range of temperature. 相似文献