共查询到20条相似文献,搜索用时 46 毫秒
1.
对CH~4+H=CH~3+H~2的非绝热trapping型的动力学进行了研究。采用量子化学从头算方法在QCISD/6-311G^*^*水平上计算了该反应的内禀反应坐标(IRC)和IRC上各构型点的振动分析,利用各构型点的信息,计算得到了共线型模型反应和真实热反应沿反应坐标不同能量下的微正则反应通量。计算结果表明共线型反应具有非绝热trapping型的特征,而真实热反应则不是非绝热trapping型。采用统一统计理论计算了300K-1500K的共线型反应的速率常数,由微正则变分过渡态计算了热反应的速率常数,得到与实验一致的结果。 相似文献
2.
以丁二酮肟和水合醋酸镍及无水醋酸镍的反应为模板, 利用反应物与产物之间的颜色差异, 通过粉末紫外-可见漫反射光谱对反应初期产物生成量的变化进行测定, 从而研究其反应动力学. 由于光谱性质与产物的晶型无关, 并且如果反应物与某一产物之间的光谱性质(如颜色)差异较大, 即使在微量产物的情况下也很容易跟踪到产物量的变化. 因此, 该方法对于固-固反应初期的动力学响应非常灵敏, 但当反应进行到一定程度后则不适用. 相似文献
3.
4.
经典铁置换铜反应的研究和工业应用 总被引:1,自引:0,他引:1
报道了铁置换铜的反应原理,通过光电子能谱测定了镀层的成份及含量,确定了体系中可能发生的全反应和副反应,开辟了一条新的镀铜技术路线。 相似文献
5.
本文提出用反应截面法研究氢氧化铜和α-alaH的室温固相反应,讨论了反应温度及表面状态等影响截面移动的因素,对表面反应速度的决定因素进行了讨论并计算了反应活化能. 相似文献
6.
7.
观测快速溶液反应的尝试,始于1923年,Roughton采用连续流动法,用热电偶测定血红朊和一氧化碳的结合速度。1940年Chance Gibson提出了截流法,用小量试样来观测过氧化氢酶或过氧化物酶与过氧化氢的反应,然后在溶液高速反应上广泛应用。另一方面酸碱的中和反应质子移动反应和氧化还原电子移动反应,则于1953年由Eigon提出了缓和法(化学驰豫)即改变温度、压力、 相似文献
8.
9.
10.
利用光纤光谱仪构建微量反应系统,并通过偶氮染料橙黄II在铁-亚硫酸钠-溶解氧体系中的脱色反应,分别用特征动力学方程法及初始速率法进行了脱色反应动力学分析。该实验体系能够实现简单、快速的均相溶液反应动力学实验,其数据处理方法较好地巩固和提升了对反应动力学理论课教学内容的学习。整个实验体系的设计与应用能够满足物理化学、大学化学、环境化学等相关课程中有关反应动力学的实验教学需求。 相似文献
11.
利用手持技术改进测定乙醇分子结构实验 总被引:1,自引:0,他引:1
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。 相似文献
12.
13.
14.
15.
Mustafa R. Ibrahim Zacharia A. Fataftah Paul von Ragu Schleyer Peter D. Stout 《Journal of computational chemistry》1987,8(8):1131-1138
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases. 相似文献
16.
V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1989,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988. 相似文献
17.
18.
V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1988,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae. 相似文献
19.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。 相似文献