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Ab Initio MO Studies on the Reaction Mechanism for Carbonyl Insertion Catalyzed by Carbonyl Cobalt Complex

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Chemical Research in Chinese Universities 2000年第1期16卷 31-35页

作者： LEI Ming FENG Wen-lin and XU Zhen-feng (Department of Applied Chemistry, Beijing University of Chemical Technology,Beijing 100029, p. R. China Department of Chemistry, Beijing Normal University, Beijing 100875, p. R. China) Beijing Univ Chem Technol Dept Appl Chem Beijing 100029 Peoples R China Beijing Normal Univ Dept Chem Beijing 100875 Peoples R China

Ab initio method, under the effective core potential(ECp) approximation at HF/LANL2DZ level, has been employed to study the reaction mechanism of the carbonyl insertion of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)_3. The two reaction paths have been discussed. The calculated potential energy barriers for the carbonyl migration and the ethyl group migration are 105. 0 kJ/mol and 39. 17 kJ/mol, respectively. The results indicate that the reaction path via ethyl migration is more energetically favorable than that via carbonyl insertion.

关键词： Carbonyl Cobalt Hydroformylation Ab initio method Effective core potential

Constitutive modeling of flow behavior of precipitation-hardened AA7022-T6 aluminum alloy at elevated temperature

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Transactions of Nonferrous Metals Society of China 2020年第11期30卷 2927-2940页

作者： H.R.REZAEI ASHTIANI p.SHAHSAVARI School of Mechanical Engineering Arak University of TechnologyArakIran

The thermomechanical behavior of precipitation-hardened aluminum alloy AA7022-T6 was studied using isothermal compression at temperatures of 623−773 K and strain rates of 0.01−1 s^−*** experimental results indicated that dynamic recrystallization(DRX)is a predominant hot deformation mechanism,especially at elevated temperatures and low strain *** modified Johnson−Cook(J−C)and the strain compensated Arrhenius-type models were developed to predict the hot flow behavior under different deformation *** correlation coefficients of modified J−C model and the strain compensated Arrhenius-type models were 0.9914 and 0.9972,respectively,their average relative errors(ARE)were 6.074%and 4.465%,respectively,and their root mean square errors(RMSE)were 10.611 and 1.665 Mpa,respectively,indicating that the strain compensated Arrhenius-type model can predict the hot flow stress of AA7022-T6 aluminum alloy with an appropriate accuracy.

关键词： flow behavior constitutive models Arrhenius model dynamic recrystallization AA7022-T6 aluminum alloy

CREVICE CORROSION BEHAVIOR OF X70 STEEL IN HCO_3^- SOLUTION UNDER CATHODIC pOLARIZATION

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 235-244页

作者： C.W. Du X.G. Li X. Chen p. Liang H. Guo School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Liaoning University of petroleum and Chemical Technology ~shun 113001 China

The crevice corrosion behavior of XTO steel was investigated with a wedge-shaped crevice assembly under -1000 m V （SCE） cathodic polarization in the solutions with various HCO3 concentrations. The potential, current, pH and the oxygen content within the crevice were measured with or without outside coupled specimen. The results indicated that the polarization potential of XTO steel in the crevice dropped with the increase of time under the cathodic polarization. There was a remarkable influence of HCO3 concentration on the potential of XTO steel in the crevice. When HCO3 concentration was up to 0.125%, the surface of the metal was covered with the corrosion products that resulted in the polarization extent of XTO steel decreased. The pH value in the crevice rose and it dropped gradually from the crevice mouth to the bottom under the cathodic polarization. With the increasing of HCO3 concentration, the hydrolyzation reaction of metal in the crevice bottom aggravated. Most of the dissolved oxygen in the crevice was consumed by the cathodic current. The maximum cathodic current on the metal surface was at the crevice mouth and it was much more than that at the crevice bottom.

关键词： Cathodic polarization XTO steel potential pH value Oxygen

Effect of tool plunge depth on joint formation and mechanical performance of friction stir forming joints made between AA 5052-H32 and AA 6061-T6 sheet metals

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Transactions of Nonferrous Metals Society of China 2018年第4期28卷 613-628页

作者： Tinu p.SAJU R.Ganesh NARAYANAN Department of Mechanical Engineering Indian Institute of Technology Guwahati

The potential of friction stir forming for joining dissimilar grades of aluminum alloys namely,AA 5052-H32 and AA 6061-T6,was *** on the effect of tool plunge depth revealed that,lap shear load of 7.16 kN and cross-tensile load of 3.51 kN,recorded at medium tool plunge depth range from 0.5 to 0.7 mm,measured using a universal testing machine,were much larger than those of friction stir welded and friction stir spot welded joints fabricated on the same *** macrostructure observed with optical microscope revealed that joints were strengthened either by mechanical pin interlocking or by metallurgical *** effect of tool plunge depth on the stir zone formation and the influence of frictional heat flux on the lower sheet were revealed through the microhardness measurement using Vickers hardness *** studies revealed that tool plunge depth has a significant influence on the pin formation and the geometric features,generated in these *** of various failure modes such as pin pull-out,pin shear,partial bond delamination,and tear-off,were governed by the formation of critical weak zones at various tool plunge depths.

关键词： friction stir forming tool plunge depth aluminum alloy lap shear test cross-tension test failure modes

Orbital Stability of Solitary Waves of The Long Wave-Short Wave Resonance Equations

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Communications in Nonlinear Science and Numerical Simulation 1996年第3期1卷 37-42页

作者： Boling GUO Lin CHEN(Institute of Applied physics and ComputationalMathemaics, p. O. Box 8009, Beijing 100088, China) Institute of Applied physics- and Computational Mathematics p. O. Box 8009 Beijing 100088 China

This paper concerns the orbital stability for solitary waves of the long waveshort are resonance equations. By using a different method from [15], applying the abstractresults of Grillakis et al. [8][9] and detailed s... 详细信息

关键词： Solitary wave stability. Long wave-short wave resonance equations

More on Bounding Introspection in Modal Nonmonotonic Logics

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Acta Mathematica Sinica,English Series 2000年第4期16卷 555-564页

作者： Xishun Zhao Decheng Ding Department of Mathematics. Nanjing University. Nanjing 210093, p. R. China Department of Mathematics Nanjing University Nanjing 210093 P. R. China

By L. we denote the set of all propositional fornmlas. Let C be the set of all clauses. Define C_n=C(Lη:η∈C}.In Sec. 2 of this paper. we prove that for normal modal logics S, the notions of (S. C_)-expansions and S-expansions coincide. In Sec. 3. we prove that if I consists of default clauses then the notions of S-expansions for I and (S.C)-expansions for I coincide. To this end. we first show. in Sec *** the notion of S-expansions for I is the same as that of (S.L)-expansions for I.

关键词： Modal nonmonotonic logic Expansion Bounding Introspection Default clause

Modelling Solitary Waves and Its Impact on Coastal Houses with SpH Method

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China Ocean Engineering 2010年第2期24卷 353-368页

作者： LIANG Dong-fang N. I. Thusyanthan S. p. Gopal Madabhushi 唐洪武 Department of Engineering University of Cambridge Cambridge CB2 1PZ UK KW Ltd Fetcham Park House Lotcer Road Fetcham Surrey KT22 91ID UK State Key Laboratory of Hydrology-Water Resources and Hydraulic Er~gineering Hohai University Nanjing 210098 China

The interaction between solid structures and free-surface flows is investigated in this study. A Smoothed particle Hy- drodynamics （SpH） model is used in the investigation and is verified against analytical solutions and experimental obser- vations. The main aim is to examine the effectiveness of a tsunami-resistant house design by predicting the wave loads on it. To achieve this, the solitary wave generation and ran-up are studied first. The solitary wave is generated by allowing a heavily weighted block to penetrate into a tank of water at one end, and the near-shore seabed is modelled by an inclined section with a constant slope. Then, the SpH model is applied to simulate the three-dimensional flows around different types of houses under the action of a solitary wave. It has been found that the tsunami-resistant house design reduces the impact force by a factor of three.

关键词： solitary waves tsunami wave impact coastal structures SpH

New Method for Constructing Comparison Matrix Based on the proportion Scales in the AHp

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Journal of Systems Engineering and Electronics 2003年第3期14卷 8-13页

作者： Huang Decai & Shen Liangzhong College of Informaton Engineering, Zhejiang University of Technology, Hangzhou 310032, p. R. China College of Informaton Engineering Zhejiang University of Technology Hangzhou 310032 P. R. China

The main faults existing in current scale methods are that the scales do not represent the real importance of alternatives and their relations. This paper presents a proportion judgment scale and introduces a new method based on the proportion scale for construction comparison matrix in the analytic hierarchy process (AHp). The proportion judgment scales do not have the faults existing in current scale methods and the comparison matrix constructed by the new scale

关键词： AHp Judgment scales Comparison matrix Consistency checking.

阿尔泰-萨彦山的新构造运动和区域控震断裂的再活化

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地学前缘 2021年第5期28卷 301-319页

作者： Mikhail M.BUSLOV Lyudmila p.IMAEVA Sobolev V.S.Institute of Geology and Mineralogy Siberian Branch of the RAS630090 NovosibirskRussia Kazan Federal University 420008KazanRussia Institute of the Earth's Crust Siberian Branch of RAS664033 IrkutskRussia Academy of Sciences of the Republic of Sakha(Yakutia) 677007 YakutskRussia

阿尔泰-萨彦山系和新构造结构的形成被认为是印度欧亚板块碰撞带来的远程陆内变形的结果。在本次构造模型中,我们对地质、地震活动数据和地形资料进行了联合分析,认为中亚山带北部地形和地震活动的最大变化仅限于晚古生代区域断层的交... 详细信息

阿尔泰-萨彦山系和新构造结构的形成被认为是印度欧亚板块碰撞带来的远程陆内变形的结果。在本次构造模型中,我们对地质、地震活动数据和地形资料进行了联合分析,认为中亚山带北部地形和地震活动的最大变化仅限于晚古生代区域断层的交叉地带。断层的交叉和接合处应被视为增加基底破碎程度、影响局部应力场变化和预先定位M≥5级的地震震源的最重要的构造因素之一。由此,结合Charysh Terekta和Kurai区域断层交叉带出现的氦和钙华,本次研究获得了发震前兆的一些判断规律。

关键词：阿尔泰-萨彦山 Kurai-Chuya盆地活动构造 2003年9月27日的阿尔泰地震断层活化控震断层