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131.
利用分子束技术改变甲烷的平动能E_k来研究E_k及其法向分量E_n对甲烷在Ni表面及La薄膜上激活解离吸附的影响。对CH_4/Ni及CH_4/La系统, 当甲烷的平动能E_k分别低于58.5 kJ·mol~(-1)及52.3 kJ·mol~(-1)时, 没观察到甲烷的解离吸附。当甲烷的平动能超过此阈值时, 即对CH_4/Ni系统, 当Ek=58.5增至63.8 kJ·mol~(-1)时, 初始沾着几率s_0由0至0.54线性增加; 对CH_4/La系统, 当E_k=52.3增至63.8 kJ·mol~(-1)时, S_0由0至0.49线性增加。这些结果表明, 两个系统的化学吸附是不经过前趋态的直接化学吸附。最后求出CH_4/Ni, CH_4/La系统的表观活化能分别为46.8 kJ·mol~(-1)和38.1 kJ·mol~(-1)。 相似文献
132.
Shao L Geib SJ Badger PD Cooper NJ 《Journal of the American Chemical Society》2002,124(50):14812-14813
We have established cation/anion coupling reactions between the tropylium ligand in [M(eta7-C7H7)(CO)3]+ (M = Cr, W) and the reductively activated eta4-benzene ligand in [Mn(eta4-C6H6)(CO)3]- (3-) to form [M(CO)3(mu2-eta6:eta5-C7H7-C6H6)Mn(CO)3]; [Cr(CO)3(mu2-eta6:eta5-C7H7-C6H6)Mn(CO)3] can be further reduced to [Cr(CO)3(mu2-eta5:eta4-C7H7-C6H6)Mn(CO)3]2-, in which the tropylium and benzene ligands have undergone a [2 + 2] cross coupling reaction. 相似文献
133.
The hydrogen abstraction reaction of O(^3P) with Si2H6 has been studied theoretially. Two transition states of ^3A″ and ^3A′ symmetries have been located for this abstraction reaction. Geometries have been optimized at the UMP2 leve with 6-311G (d) basis set. G3MP2 has been used for the final single-point energy calculation. The rate constants have been calculated over a wide temperature range of 200-3000K using canonical variational transition-state sheory (CVT) with small curvature tunneling effect(SCT). The calculated CVT/SCT rate constants match well with the experimental value. 相似文献
134.
135.
Shao Qiman 《分析论及其应用》1991,7(1):35-38
In [1], Butzer and Kirschfink discussed the convergence rates for C[0,1]-valued dependent random functions on Donsker's weak invariance principle and introduced the concept of dependency from below to deal with the martingale difference sequence. They asserted in their Lemma 8 that Lemma A. A martingale difference sequence (Xn,Fn,n≥1) with is dependent from below, i.e., for each 1≤i≤n and each n≥1 . The purpose of this note is to prove that Lemma A is not always true and to improve the conditions of Butzer and Kirschfink. We shall apply the notations in [1]. 相似文献
136.
137.
ZhuanNiYU XiRong HUANG ShaoFangSONG DanWANG XueMeiLU YueZhongLI YinBoQU PeiJiGAO 《中国化学快报》2003,14(8):836-839
The inhibition of lingninase by hydrogen peroxide in the presence of cationic surfactant CTAB was studied by kinetic speetrophotometdc technique. Results showed that addition of CTAB enhanced the inhibition by H202, but it did not alter the inhibition pattern and the inhibition constant changed little with theco-ncentration of CTAB. Modification of the enzymic protein by the surfactant monomer may be responsible for the above mentioned results. 相似文献
138.
Jie Shao Hai Lin Xue-Fang Shang Hua-Mei Chen Hua-Kuan Lin 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(3-4):371-375
A new urea-based receptor was designed to selectively recognize H2PO4− among other anions (such as F-, Cl-, Br-, I-, OH-, AcO-) in organic solvent (DMSO) through intermolecular hydrogen bonding. Addition of anions to the receptor caused changes in
UV–vis spectrum which provided the first indication of its anion binding ability.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
139.
140.
A series of Al=-(Alq3)l-x granular films is prepared on Si wafer with native oxide layer using co-evaporation technique. Large lateral photovoltaic effect (LPE) is observed, with an optimal LPV sensitivity of 75 mV/mm in x=0.35 sample. The dependence of LPE on temperature and A1 composition is investigated, and the possible mechanism is discussed. 相似文献