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61.
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依据柱相比的热力学定义和反相液相色谱中溶质的计量置换保留理论(the stoichiometric dispheement heory of solute for retention,SDT-R),对反相液相色谱中固定相和流动相性质、温度对柱相比的影响进行了研究。结果表明:固定相的种类和配基的疏水性对柱相比影响较大,而流动相中有机溶剂的种类,特别是脂肪酸作为置换剂时,对柱相比的影响更大,而柱相比受温度的影响较小。此外,通过用27种小分子溶质对柱相比的测定,其logI和Z良好的线性关系,进一步证明柱相比是一个与溶质性质无关的常数。 相似文献
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The refolding of the reduced-denatured insulin from bovine pancreas was investigated with the size exclusion chromatography (SEC). It was shown that the reduced-denatured insulin originally denatured with 7.0 mol L?1 guanidine hydrochloride (GuHCI) or 8.0 mol L?1 urea could not be refolded with a non-oxidized mobile phase. Although the oxidized and reduced glutathione (GSSG and GSH) were employed in the oxidized mobile phase, the reduced-denatured insulin still could not be renatured. However, in the presence of 2.0 mol Lt-1 urea in the oxidized mobile phase employed, the reduced-denatured insulin can be refolded with SEC, and the aggregation of denatured insulin can be diminished by urea. In addition, the disulfide exchange of reduced-denatured insulin also can be accelerated with GSSG/GSH in the oxidized mobile phase. The three disulfide bridges of insulin were formed correctly and the reduced-unfolded insulin can be renatured completely. The results were further tested with reversed-phase liquid chromatography (RPLC) and hydrophobic interaction chromatography (HIC). 相似文献
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The pollution characteristics of ambient fine particulate matter(PM2.5) containing polycyclic aromatic hydrocarbons(PAHs) and nitrated PAHs(NPAHs) in samples collected during a typical winter time period in Taiyuan of China were investigated.The obtained results revealed that the mean mass concentrations of PM2.5,SPAHs(sum of 16 PAHs) and SNPAHs(sum of 3 NPAHs) on PM2.5were161.4 mg/m3,119.8 ng/m3and 0.446 ng/m3,respectively.Diagnostic ratios of PAHs and NPAHs implied that coal consumption might be the main source of the PM2.5pollution.The measured PM2.5mass concentrations,BaP equivalent toxicity(28.632 ng/m3) and individual carcinogenicity index(3.14 10 5) were much higher than those of the recommended safety standards. 相似文献
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将二(3-二甲氨基丙基)丙二酰胺分别与溴代十六烷和溴代十四烷反应,生成的季铵盐化产物经丙酮-乙腈重结晶,得到含丙二酰胺基的不对称阳离子双子(Gemini)表面活性剂(命名为16-9-14),总收率为45.9%(以溴代十六烷计);利用红外光谱和核磁共振谱表征了合成产物的结构,采用电导法测定了其临界胶束浓度(CMC),采用滴体积法测定了其临界张力(γCMC),进而初步探讨了其发泡沫性能和乳化性能.结果表明,合成的Gemini表面活性剂的CMC为1.57×10-4 mol/L,γCMC为38.45mN/m;其发泡性能和乳化性能优于相应的单子表面活性剂. 相似文献
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Chuantian Zuo Prof. Liming Ding 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6628-6632
A family of perovskite light absorbers (NH4)3Sb2IxBr9−x (0≤x≤9) was prepared. These materials show good solubility in ethanol, a low-cost, hypotoxic, and environmentally friendly solvent. The light absorption of (NH4)3Sb2IxBr9−x films can be tuned by adjusting I and Br content. The absorption onset for (NH4)3Sb2IxBr9−x films changes from 558 nm to 453 nm as x changes from 9 to 0. (NH4)3Sb2I9 single crystals were prepared, exhibiting a hole mobility of 4.8 cm2 V−1 s−1 and an electron mobility of 12.3 cm2 V−1 s−1. (NH4)3Sb2I9 solar cells gave an open-circuit voltage of 1.03 V and a power conversion efficiency of 0.51 %. 相似文献
70.
Titanium and its alloys are used in production of implants such as knee and hip prostheses due to their superior properties. Ti–Nb–Zr ternary alloys are preferred over other metallic implant materials due to the presence of non-toxic elements, high corrosion resistance, good biocompatibility, and proper mechanical properties. The aim of this work is to investigate the effect of zirconium addition on α → β phase transformation, microstructure, and mechanical behavior of Ti–16Nb alloy. In doing so, Ti–16Nb–xZr (x: 0, 5, 10, 15 mass%) alloys are produced by powder injection molding, which offers advantages such as low cost, net shape, and easy production of complicated parts for implant fabrication. X-ray diffraction analysis and scanning electron microscope images showed that zirconium behaves as a β stabilizer and according to differential thermal analysis, and it decreases α to β transition temperature approximately 30 °C. It is also revealed that increasing zirconium content caused finer microstructure and hardness of the alloy was raised from 336 HV0.5 to 412 HV0.5 while elastic modulus remains approximately steady between 103 and 110 GPa. It is concluded that Ti–Nb–Zr alloys have been found to be a good alternative to known metallic implant materials. 相似文献