共查询到20条相似文献,搜索用时 156 毫秒
1.
芳基异硫氰酸酯是一类应用极为广泛的有机中间体和重要试剂,用于合成多种含氮、含硫、或含氧等杂环化合物,广泛应用于农药、医药和精细化工等领域。其合成方法及应用受到化学家的广泛重视。文章综述了芳基异硫氰酸酯的多种合成方法及其在化合物合成、医药方面的应用。 相似文献
2.
嗪草酸属稠杂环化合物,其合成工艺难度很大,尤其是中间体制备的反应步骤多,机理复杂,需要严格控制异构物的生成,因此选择合理、实用的工艺路线是非常重要的环节。而2-氟-4-氯-5-甲氧羰基甲硫基苯基异硫氰酸酯(以下简称异硫氰酸酯)是嗪草酸合成过程中一个非常重要的中间体。以下从硝化法工艺合成异硫氰酸酯的合理性进行论述。 相似文献
3.
综述了近几年来关环复分解(RCM)反应的研究新进展,包括了烯烃、烯-炔的RCM反应。着重讨论了RCM反应在合成杂环化合物中的应用。 相似文献
4.
5.
6.
7.
8.
9.
综述了近年芳杂环反应型阻燃聚醚多元醇的研究进展,包括含有苯环、异氰脲酸酯环、亚胺基三嗪环等杂环结构的聚醚多元醇,并展望了本领域的发展趋势。 相似文献
10.
概述了不同过渡金属催化下通过炔基和磺酰胺基反应,形成N-磺酰基取代的杂环化合物。由于过渡金属催化合成N杂环类化合物的方法高效便捷,因而具有广泛的研究前景。 相似文献
11.
乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
12.
D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
13.
15.
16.
Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
17.
18.
19.
A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
20.
醋酸纤维素取代基分布与性质的关系 总被引:9,自引:0,他引:9
分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。 相似文献