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Changes to the fundamental and analytical parameters of a plasma have been investigated when ethanol has been added to aqueous or organic solutions. Excitation temperature, electron number density, and intensity of the H line increased when ethanol has been added to aqueous solutions, while an electron density decrease and signal reduction have been found when ethanol has been added to xylene. The sensitivity has been improved for all ethanol concentrations when water has been the solvent, but the reverse has been found for xylene solutions. 相似文献
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A study has been made of the principal rearrangement products resulting from formic acid treatment of 19-hydroxy-ent-beyerene epoxide (3). In concentrated solutions 3 has been found to undergo a deep seated rearrangement to the allylic alcohol (14). A mechanism for the formation of 14 is proposed involving a novel 1,4-hydride shift in the bicyclo[3:2:1]octane C/D ring system following cleavage of the C15O bond. Supporting evidence has been obtained from a study of the specifically labelled epoxide (4), the deuterium in 14 appearing exclusively at C12. Four products (7 and 11–13) emanating from the known beyerane → kaurane interconversion have been identified. 相似文献
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Changes to the fundamental and analytical parameters of a plasma have been investigated when ethanol has been added to aqueous or organic solutions. Excitation temperature, electron number density, and intensity of the H(alpha) line increased when ethanol has been added to aqueous solutions, while an electron density decrease and signal reduction have been found when ethanol has been added to xylene. The sensitivity has been improved for all ethanol concentrations when water has been the solvent, but the reverse has been found for xylene solutions. 相似文献
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采用沉淀法制备前驱体,通过不同温度合成了上转换发光材料Y2O2S∶Er3+,Yb3+,运用XRD,SEM和上转换发射光谱对其进行表征。结果表明,所合成的Y2O2S∶Er3+Yb3+属于六方晶系晶体,随着合成温度的升高,产物的粒径不断增大,上转换发射光强度逐渐增加。研究Y2O2S∶Er3+Yb3+的上转换发光过程,红光发射和绿光发射分别源于Er3+离子的4F9/2→4I15/2以及2H11/2→4I15/2,4S3/2→4I15/2能级跃迁。利用群论计算了晶场中Er3+离子的能级分裂数目。 相似文献
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Robert McCrindle Alan J. McAlees Erle Zang George Ferguson 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e132-e133
The synthesis and X‐ray structural analysis of the title compound, [PdCl2(C3H7N)(C18H15P)]·C3H6O, are described. The crystal structure contains discrete monomeric molecules of the carbene complex and solvent molecules separated by normal van der Waals distances. The Pd atom is four‐coordinate in an essentially square‐planar environment, with the chlorine ligands mutually cis; Pd—P = 2.2495 (7), Pd—Cl = 2.3508 (7) and 2.3600 (7), Pd—C 1.948 (2) and N—C(carbene) 1.274 (3) Å. 相似文献
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本文主要研究如下含非线性梯度项的非强制拟线性椭圆方程\begin{equation*}\left \{\begin{array}{rl}-\text{div}(\frac{|\nabla u|^{p-2}\nabla u}{(1+|u|)^{\theta(p-1)}})+\frac{|u|^{p-2}u|\nabla u|^{p}}{(1+|u|)^{\theta p}}=\mu,~&x\in\Omega,\\ u=0,~&x\in\partial\Omega,\end{array}\right.\end{equation*} 弱解的存在性和不存在性, 其中$\Omega\subseteq\mathbb{R}^N(N\geq3)$ 是有界光滑区域, $1
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