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41.
惰性配合物在铂族金属分离和测定中的应用 总被引:1,自引:0,他引:1
介绍了铂族金属在形成各种配合物时不同的动力学性质,评述惰性配合物在铂族金属分离和测定中的应用。 相似文献
42.
介绍了石化集团原油资源现状,分析了原油资源配置过程中存在的主要问题,提出了资源优化配置的原则与基本思路,及实施原油资源优化配置的配套措施和建议。 相似文献
43.
A new aromatic diamine monomer containing benzoxazole substituents was prepared by a multistep synthesis starting from 1,4‐dibromo‐2,5‐difluorobenzene. The diamine was polymerized with commercial aromatic dianhydride or dicarboxylic acid chloride monomers to provide several different poly(amic acid)s and polyamides with their inherent viscosities in the range of 0.24–0.46 dL/g. Thermal properties of these polymers including thermal imidization of poly(amic acid)s into polyimides were investigated by using FTIR, DSC, and TGA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 178–185, 2004 相似文献
44.
Vapor-liquid equilibrium data for the binary systems methyl butanoate/ethanol and methyl butanoate/propan-l-ol at pressures of 114.66 and 127.99 kPa are presented. Both mixtures yield an azeotrope, the compositions (ester) of which decrease quasi-linearly as the pressure increases. The experimental data for all the binary mixtures were fitted to a suitable equation and then used for comparison with predictions by ASOG and UNIFAC methods. These group contribution models give a good estimation of activity coefficients with an overall mean error less than 5% for all cases. 相似文献
45.
46.
Polystyrene (PS)/poly(ethylene oxide) (PEO) prototype brushes were prepared by alternating free‐radical copolymerization of methacryloyl‐terminated PS and α‐vinylbenzyl‐ω‐hydroxy or α‐vinylbenzyl‐ω‐perfluoroalkyl (Rf) PEO macromonomers with the addition of Lewis acid (SnCl4). It was found from their dilute‐solution properties that PS/PEO end‐capped with Rf (PBRf), and PS/PEO having OH groups at terminal ends (PBOH) prototype brushes formed a single molecule in benzene and aggregates in chloroform, respectively. However, the brush PBOH formed a single molecule in N,N‐dimethylformamide. Such aggregation behaviors seemed to be caused by the interaction between hydroxy groups of PEO chain ends. The brush PBOH was also converted into PBRf‐type brush by chemical modification, using corresponding acid chloride. The substitution of Rf groups was ~70% due to slipping of terminal hydroxy groups into PEO internal domains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 772–778, 2006 相似文献
47.
通过对原可行性研究报告中的锅炉房用煤采用筒仓群贮存方案的了解、分析、比较后,提出了采用矩形库贮存煤的优化方案设计的成果。 相似文献
48.
Marioara Onciu 《应用聚合物科学杂志》2007,103(3):2013-2020
A series of new aromatic polyamides containing cinnamide pendent units were prepared from 2′‐(cinnamide)ethyl‐3,5‐diaminobenzoate and various aromatic dicarboxylic acids by the direct polycondensation reaction, with triphenyl phosphite and pyridine as condensing agents. The polyamides were characterized by 1H NMR, IR, and UV spectroscopy, and gel permeation chromatography. Their thermal stability was studied by thermogravimetric analysis in air, and differential scanning calorimetry. These polymers were readily soluble in polar aprotic solvents and can be cast from their solutions in flexible and tough films. Glass transition temperatures (Tgs) of these polyamides were observed in the range of 225–245°C. Their inherent viscosities varied from 0.77 to 1.12 dL/g that corresponded to weight–average and number–average molecular weights of 39,000–72,700 and 18,800–29,000, respectively. These polymers can be photochemically crosslinked. The photochemical aspects were revealed by means of UV–vis and IR analyses onto thin films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2013–2020, 2007 相似文献
49.
3-DOF translational parallel manipulators have been developed in many different forms, but they still have respective disadvantages in different applications. To overcome their disadvantages, the structure and constraint design of a 3-DOF translational parallel manipulator is presented and named the Tri-pyramid Robot. In the constraint design of the presented manipulator, a conical displacement subset is defined based on displacement group theory. A triangular pyramidal constraint is presented and applied in the constraint designs between the manipulator?s subchains. The structural properties including the decoupled motions, overconstraint elimination, singularity free workspace, fixed actuators and isotropic configuration are analyzed and compared to existing structures. The Tri-pyramid Robot is constrained and realized by a minimal number of 1-DOF joints. The kinematic position solutions, workspace with variation of structural parameters, Jacobian matrix, isotropic and dexterity analysis are performed and evaluated in the numerical simulations. 相似文献
50.
Ⅱ型B族链球菌表面免疫相关蛋白基因的克隆和原核表达 总被引:1,自引:1,他引:1
目的重组表达Ⅱ型B族链球菌表面免疫相关蛋白(Surfaceimmunogenicprotein,SIP)基因,为进一步免疫学研究提供目标蛋白。方法用PCR的方法从GBSⅡ型标准株的基因组DNA中扩增出SIP基因,用T/A克隆法将其插入pMD18T载体,构建原核表达载体pET32aSIP,用BL21(DE3)/pET系统表达TrixSIP融合蛋白,SDSPAGE和质谱分析鉴定表达产物,并对表达蛋白进行初步纯化。结果PCR扩增产物经测序,证实与GenBank中Ⅰa/c型GBS的SIP的基因序列同源性为99%。SDSPAGE显示,经IPTG诱导后BL21(DE3)/pET32aSIP总蛋白中出现一条相对分子质量为66000的新蛋白带。质谱分析和蛋白质库的比较证实其为B族链球菌表面免疫相关蛋白(SIP)的可能性分数为74。结论已成功表达并初步纯化SIP,为SIP在细菌致病中的作用研究以及相关疫苗的制备奠定了基础。 相似文献