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151.
本文分析了等压实验中温度因素的影响和各种单独过程的平衡方程,理论研究得到了实验设备中的温度差和测定的平衡浓度误差的关系以及平衡方程,平衡方程也表明了各单独过程的平衡速度大小顺序为气相中的水蒸气扩散过程<气相中的水蒸气循环流动过程<试样溶液中热传导过程<热传导体中的热传导过程和试样溶液中由搅拌产生的热传递过程<溶质在溶液中的扩散过程<气液相之间的平衡过程和由压强差产生的气相的水蒸气对流过程.同时,研究表明总的平衡方程可以近似由dln|△me,b/m0|/dt=-k·mb2/(ma·wa)描述.此外研究也表明排除等压实验设备中的空气成分可以有效的加快总的平衡速度.并且实验容器与热传导体之间的接触也非常重要. 相似文献
152.
基于Ziegler-Natta催化剂的氯硅烷功能化非共轭α,ω-双烯烃与丙烯共聚,在水的引发下脱水缩合可有效地形成长支链结构的聚丙烯树脂.而氢气常作为丙烯聚合中的链转移剂,调控聚丙烯的分子量,基于此,研究了氢气对氯硅烷功能化非共轭α,ω-双烯烃与丙烯共聚物链结构的影响.核磁共振氢谱(~1H-NMR)测试结果表明,氢气抑制了氯硅烷功能化非共轭α,ω-双烯烃的插入,随着氢气用量的增加,共聚物分子链中端基乙烯基含量由0.12 mol%降低到0.05 mol%.熔体流变行为测试结果显示,聚合物熔体的储能模量、损耗模量和零剪切黏度均随着氢气用量增加而降低,这主要是由于相对分子质量减小和长支链密度的减少. 相似文献
153.
影响苯胺电化学计量聚合因素的探讨 总被引:5,自引:0,他引:5
本文对影响苯胺电化学计量聚合的因素进行了探讨,这些因素包括:电化学聚合方法、电极电位(E)、电流密度(I),以及苯胺单体和酸溶液的浓度等,实验结果表明,最合适的聚合方法为恒电流法,其条件为:电极电位不大于0.70V(vs.SCE)聚合电流密度(I)约为0.05mA/cm^2,苯胺单体浓度为1.1mol/L,酸(HCl)的浓度则为2.2mol/L 相似文献
154.
ThestudyofphotoionizationandphotodissociationprocessesinducedbyintensefemtosecondlaserpuIses(>lo"W/cm')withpolyatomicmoleculesbecomesofinterestbecausesomenewphenomenahavebeenobserved'-3.Sofar,mostoftheinvestigationsfocusontheexperimentalexplorationofphotoionizationprocesses'-'.Butthephotoionizationmechanismofpolyatomicmoleculesinanintensefslaserfieldisstillambiguous'.,.Incontrasttothephotoionizationprocesses,theunderstandingoffragmentationofmolecularionisevenpoorer.Corkumetal,'.,'reportedthef… 相似文献
155.
Redl FX Black CT Papaefthymiou GC Sandstrom RL Yin M Zeng H Murray CB O'Brien SP 《Journal of the American Chemical Society》2004,126(44):14583-14599
We have investigated the structural, magnetic, and electronic properties of nonstoichiometric iron oxide nanocrystals prepared by decomposition of iron(II) and iron(0) precursors in the presence of organic solvents and capping groups. The highly uniform, crystalline, and monodisperse nanocrystals that were produced enabled a full structural and compositional survey by electron microscopy and X-ray diffraction. The complex and metastable behavior of nonstoichiometric iron oxide (wüstite) at the nanoscale was studied by a combination of Mossbauer spectroscopy and magnetic characterization. Deposition from hydrocarbon solvents with subsequent self-assembly of iron oxide nanocrystals into superlattices allowed the preparation of continuous thin films suitable for electronic transport measurements. 相似文献
156.
Rozing G van de Goor T Yin H Killeen K Glatz B Kraiczek K Lauer HH 《Journal of separation science》2004,27(17-18):1391-1401
A systematic investigation of the influence of the perimeter shape of open and particle packed fused silica capillaries on chromatographic properties such as resistance to flow and dispersion of solutes propelled through these channels has been conducted. Verifications of these uncommon experiments with existing theoretical treatments are presented and the insights transferred to a novel polymer chip design with integrated facilities for complex separations. A comparison of the chromatographic performance of a real life proteomics sample on this chip with a capillary column of "similar" dimensions is presented. 相似文献
157.
Changjun Peng Shouhong Xu Hongze Gang Tianxiang Yin Jun Hu Yazhuo Shang Honglai Liu Encheng Hei 《大学化学》1986,36(1):2006013-0
As a necessary basic theory course for undergraduates majoring in chemistry, materials, pharmacy, chemical engineering, and biology, physical chemistry plays an important role in cultivating talents to meet the needs of social and economic development. Over the years, the teaching team of physical chemistry of East China University of Science and Technology has carried out the curriculum reform and innovation persistently based on "Team building as the foundation, resource building as the root, mode innovation as the soul, ability training as the origin". This paper will summarize our thinking and experience in striving for the first-class course from the aspects of first-class team construction, first-class resource construction, teaching connotation innovation, teaching mode exploration, and extract the experience that can be used as reference by teaching peers. 相似文献
158.
In this paper, the authors study the multiplicity of solutions to the weighted p-Laplacian with isolated singularity and di?usion suppressed by convection ?div(|x|α|?u|p?2?u) + λ 1/|x|β |?u|p?2?u · x = |x|γg(|x|) in B \ {0} subject to nonlinear Robin boundary value condition |x|α|?u|p?2?u · ?n = A ? ρu on ?B,where λ > 0, B ? RN(N ≥ 2) is the unit ball centered at the origin, α > 0, p > 1, β ∈ R, γ > ?N, g ∈ C([0,1]) with g(0) > 0, A ∈ R, ρ > 0 and ?n is the unit outward normal. The same problem with di?usion promoted by convection, namely λ ≤ 0, has already been discussed by the last two authors (Song-Yin (2012)), where the existence, nonexistence and classi?cation of singularities for solutions are presented. Completely di?erent from [Song, H. J. and Yin, J. X., Removable isolated singularities of solutions to the weighted p-Laplacian with singular convection, Math. Meth. Appl. Sci., 35, 2012, 1089–1100], in the present case λ > 0, namely the di?usion is suppressed by the convection, non-singular solutions are not only existent but also may be in?nite which vary according only to the values of solutions at the isolated singular point. At the same time, the singular solutions may exist only if the di?usion dominates the convection. 相似文献
159.
Czechoslovak Mathematical Journal - A nonincreasing sequence π = (d1,…, dn) of nonnegative integers is a graphic sequence if it is realizable by a simple graph G on n vertices. In this... 相似文献
160.
Let be a Kähler surface and be a -symplectic critical surface in . If is bounded for some , then we give a uniform upper bound for the Kähler angle on . This bound only depends on and the functional of . For , this estimate is known and we extend the scope of . 相似文献