排序方式: 共有25条查询结果,搜索用时 15 毫秒
1.
2.
The chemical kinetics of the monoesterification between terephthalic acid (TPA) and 1,4-butanediol (BDO) catalyzed by a metallo-organic compound was studied using the initial rate method. The experiments were carried out in the temperature range of 463-483 K, and butylhydroxyoxo-stannane (BuSnOOH) and tetrabutyl titanate [Ti(OBu)4] were used as catalyst respectively. The initial rates of the reaction catalyzed by BuSnOOH or Ti(OBu)4 were measured at a series of initial concentrations of BDO (or TPA) with the concentration of TPA (or BDO) kept constant. The reaction orders of reagents were determined by the initial rate method. The results indicate that the reaction order for TPA is related with the species of catalyst and it is 2 and 0.7 for BuSnOOH and Ti(OBu)4 respectively. However, the order for BDO is the same 0.9 for the two catalysts. Furthermore, the effects of temperature and catalyst concentration are investigated, and the activation energies and the reaction rate constants for the two catalysts were deter-mined. 相似文献
3.
为了分析水泥锶渣混凝土用于低交通量道路路面的可行性,采用正交方法分析了水泥用量、用水量(坍落度)、砂率、碎石级配等因素对水泥锶渣混凝土抗压强度和抗折强度的影响规律,优选出合理的材料配合比;试验对不同水泥用量的水泥锶渣混凝土的力学性能、干缩性能、温缩性能和抗冻性能进行了系统评价.结果表明:水泥锶渣混凝土强度低于普通C30混凝土,但“折压比”高,弹性模量小,具有较好的抗裂性能;于缩系数比普通混凝土低20%,温缩系数为普通混凝土的53%,具有优良的抗收缩性能;抗冻性能低于普通混凝土;水泥锶渣混凝土可用于非冰冻地区低交通量道路路面. 相似文献
4.
5.
服装聚酯热熔胶的制造配方及工艺的复杂性,使其性能指标的调节和控制具有一定难度,结合有关理论,总结了在生产实践中积累的有关这方面的经验。 相似文献
6.
7.
8.
In this paper,a kinetics model for the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid catalyzed by cobalt-manganese-bromide is proposed.The effects of the reaction temperature,catalyst concentration and ratio of catalyst on the time evolution of the experimental concentration for the constituents including raw material,intermediates and product are investigated.The model parameters are determined in a nonlinear optimization,minimizing the difference between the simulated and experimental time evolution of the product composition obtained in a semi-batch oxidation reactor where the gas and liquid phase were well mixed.The kinetics data demonstrate that the model is suitable to the liquid-phase oxidation of 2-methyl-6-acetyl-naphthalene to 2,6-naphthalene dicarboxylic acid. 相似文献
9.
水性聚氨酯胶黏剂的制备与发展概况 总被引:2,自引:0,他引:2
介绍了制备水性聚氨酯的原料及方法,简述了国内外水性聚氨酯胶黏剂的研究现状,指出水性聚氨酯胶黏剂将在黏接领域占据越来越重要的地位,其发展趋势是高性能、高固含量、低成本。 相似文献
10.
对于多种掺合料的高性能混凝土,找出诸多影响性能因素中的关键因素对配合比设计具有现实意义.通过强度试验,运用灰关联熵的系统分析方法,分析了胶水比、水泥强度、水泥掺量、磨细矿渣粉掺量、硅灰及膨胀剂掺量等因素对高性能混凝土28 d抗压强度性能影响的主次关系和影响程度.分析表明:对于高性能混凝土,胶水比始终是一个非常重要的参数,同时水泥的强度及其在胶凝材料中的掺量也是混凝土强度的重要保证;外加剂及矿物掺合料对混凝土强度的贡献则取决于外掺料本身的性能.结果证明:在高性能混凝土多因素的分析中,灰关联熵法是一种简单实用且结果比较准确的方法,研究结果可为高性能混凝土配合比设计参数提供有效的计算依据. 相似文献