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991.
Jingqi Guan Ying Yang Bo Liu Yuanyuan Ma Xiaofang Yu Jing Liu Qiubin Kan 《Reaction Kinetics and Catalysis Letters》2008,95(2):313-320
MoV0.3Te0.17 and MoV0.3Te0.17Nb0.12 catalysts were prepared by a hydrothermal synthesis route and tested for the oxidation of isobutane and isobutene. Characterization
results showed that the structure and property of Mo-V-Te-based catalysts are relatively different depending on the presence
of the Nb element. Catalytic tests showed that the selectivity of methacrolein can comparatively be improved by the addition
of Nb into the MoV0.3Te0.17 catalyst for the selective oxidation of isobutane. 相似文献
992.
We give an elementary proof of the existence of an asymptotic expansion in powers of k of the Bergman kernel associated to L
k
, where L is a positive line bundle over a compact complex manifold. We also give an algorithm for computing the coefficients in the
expansion. 相似文献
993.
Instantaneous phase shifting arrangement for microsurface profiling of flat surfaces 总被引:1,自引:0,他引:1
Phase shifting interferometry is a well-established technique for non-contact surface profile measurement. Though phase shifting technique has many advantages, it is marred by a few inaccuracies due to the vibration and mechanical movement of the phase shifter itself. Significant amount of work is reported to theoretically compensate these error sources. But for a few works, prominent achievements have not been reported in eliminating these error sources in phase shifting interferometry. In this paper, a novel optical layout, in combination with instantaneous phase shifting interferometry is described. Experiments were carried out with this setup on a super mirror with a λ/20 surface roughness, to demonstrate the validity of the principle. 相似文献
994.
Qianying Sheng Wenqing Zhang Yan Wang Yi Zhao Haiyan Liu Junhong Qian Bo Zhang Qing Wang Ping Hu 《大学化学》1986,36(1):2002027-0
In order to solve the issues of traditional teaching methods in the undergraduate basic theory course, the blended learning mode was put forward by taking analytical chemistry as an example. With concept of student-centered, personalized teaching, together with assistant means, was introduced to achieve the breakthrough in solving the problems. We hope to reinforce the adaptability and targeting of the course teaching. 相似文献
995.
996.
997.
Jiaye Li Jinping Wu Chenggang Zhou Bo Han Xinjian Lei Roy Gordon Hansong Cheng 《International journal of quantum chemistry》2009,109(4):756-763
We present a first‐principles study on the relative stability of cobalt‐ and nickel‐based amidinate complexes against β‐migration using density functional theory. Factors that influence the reactivity of these compounds were carefully addressed and the calculated molecular structures are in excellent agreement with the available crystal structural data. Reaction energies as well as activation barriers of β‐migration were evaluated. The predicted relative stability of the selected compounds is consistent with experimental observations. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 相似文献
998.
Crystalline polymorph is an intriguing phenomenon that the presence of multiple packing and aggregate architectures of the same molecular system.In this review,we focus on the recent progress in various feasible methods of molecule-based crystalline polymorphism growth,their adjustable photofunctional properties and multifunctional applications,which will help to illustrate the structure-property relationship. 相似文献
999.
Bo Zheng Yiquan Liu Huihui Li Yunhua Ye Xingming Gao Gu Yuan 《Journal of mass spectrometry : JMS》2009,44(10):1478-1481
In this research, the characteristic ions' abundance ratio between two isomers A and B in MS/MS mass spectra was defined as a parameter for discriminating diastereomers. Through this ratio, the discrimination of four pairs of cyclic peptide (CP) diastereomers was successfully achieved. Furthermore, in the analysis of diastereomers' mixtures, both calibration curve and calculational methods were substantiated to have high precision and accuracy. The average absolute errors of the two methods were 2.0 and 2.5% in the 48 measurements of 16 samples, respectively. This research provided a promising approach for the analysis of the CP diastereomers in the fields of asymmetrical synthesis, chiral natural products and structural biology by ESI‐MS/MS. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
1000.
Four mesocyclic and one macrocyclic trithiaethers have been synthesized using a sulfide ion transfer from a vicinal dithiolate. The mechanism of the sulfide ion transfer is discussed. An improved method for synthesizing 2-hydroxymethyl-1,4,8,11-tetrathiacyclotetradecane is also reported. 相似文献