共查询到20条相似文献,搜索用时 93 毫秒
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相转移催化合成DL丙氨酸的研究 总被引:1,自引:1,他引:0
研究了以乙醛为原料,在相转移催化剂存在下与氯仿、氨水作用,一步合成DL 丙氨酸的实验新方法。在n(氯仿)n( 乙醛) =2 .0∶1、反应温度0 ~3℃和搅拌转速500rmin 等条件下,产品收率达65% 、纯度98.6% 、熔点270℃,并对产品进行了IR分析、鉴定 相似文献
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筛选了乙醛聚合生成三聚乙醛的催化剂;考察了在不同浓度的盐酸催化下三聚乙醛生成速率与反应时间的关系,研究表明:在盐酸质量分数≥70×10-6、反应温度30℃、反应时间1h条件下,乙醛转化率达69 40%,生成三聚乙醛的选择性接近100%;测量了20~80℃之间乙醛聚合生成三聚乙醛反应的平衡浓度,计算出相应的反应平衡常数,并根据范德霍夫方程求得该反应的反应热为-78 663kJ/mol。 相似文献
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LB205型CO低温变换催化剂的研制开发 总被引:1,自引:0,他引:1
介绍了新型CO低温变换催化剂的研制情况。研制的LB205型低温变换催化剂在压力≤5.0MPa,温度185-250℃.汽/气比0.2~0.6.干气空速1000~4000h^-1.干气中CO体积分数2.5%~4.0%.CO2体积分数16%~19%.余量为H2+N2条件下,催化剂CO变换率≥95%,400℃耐热2h后CO变换率≥93%。满足工厂对低变催化剂的要求.尤其适合在节能型合成氨厂的低汽/气比条件下使用。 相似文献
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研究了聚丙烯酸铵(NH4PAA)用量、离子强度等对凹凸棒石粘土的流变性影响。研究表明,在凹凸棒石粘土悬浮液中添加NH4PAA分散剂可使粘土流变性获得很大的改善。pH为8.5时,添加量为4.5%NH4PAA分散剂,可以制备分散良好的凹凸棒石粘土悬浮液,而且pH提高,分散剂最佳添加量减少。电解质NaCl使凹凸棒石粘土的流变性下降。但NaCl浓度从0.5mol/L变化到1.0mol/L时悬浮液的流变性基本不变。 相似文献
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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
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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.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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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
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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
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献