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Organocatalytic asymmetric allylic alkylation of sulfonylimidates with Morita-Baylis-Hillman carbonates

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Science china Chemistry 2011年第1期54卷 81-86页

作者： PENG Jing,CUI HaiLei & CHEN YingChun key laboratory of Drug-Targeting and Drug Delivery System,Ministry of Education Department of Medicinal Chemistry,West china School of Pharmacy,Sichuan University,chengdu 610041,china 1. key laboratory of Drug-Targeting and Drug Delivery System Ministry of Education Department of Medicinal Chemistry West China School of Pharmacy Sichuan University Chengdu 610041 China

The asymmetric allylic alkylation reaction of sulfonylimidates with various Morita-Baylis-Hillman (MBH) carbonates was accomplished by the catalysis of commercially available cinchona alkaloids catalyst (DHQD)*** corresponding allylic alkylation products were obtained in good yields with high stereoselectivities (up to 99% ee,89:11 dr).

关键词： organocatalysis asymmetric allylic alkylation sulfonylimidates Morita-Baylis-Hillman carbonates cinchona alkaloids

Mechanical decision for a class of integral inequalities

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Science china(Information Sciences) 2010年第9期53卷 1800-1815页

作者： YANG Lu1,3,YU WenSheng1,2* & YUAN RuYi2 1Shanghai key laboratory of Trustworthy Computing,Software Engineering Institute,East china Normal University,Shanghai 200062,china 2The key laboratory of Complex Systems and Intelligence Science,Institute of Automation,Chinese Academy of Sciences,Beijing 100190,china 3laboratory for Automated Reasoning and Programming,chengdu Institute of Computer Applications,Chinese Academy of Sciences,chengdu 610041,china 1. Shanghai key laboratory of Trustworthy Computing Software Engineering Institute East China Normal University Shanghai 200062 China3. Laboratory for Automated Reasoning and Programming Chengdu Institute of Computer Applications Chinese Academy of Sciences Chengdu 610041 China2. The Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing 100190 China

A class of integral inequalities is transformed into homogeneous symmetric polynomial inequalities beyond Tarski model,where the number of elements of the polynomial,say n,is also a variable and the coefficients are functions of *** is closely associated with some open problems formulated recently by Yang et *** Timofte's dimension-decreasing method for symmetric polynomial inequalities,combined with the inequality-proving package BOTTEMA and a program of implementing the method known as successive difference substitution,we provide a procedure for deciding the nonnegativity of the corresponding polynomial inequality such that the original integral inequality is mechanically decidable;otherwise,a counterexample will be *** effectiveness of the algorithm is illustrated by some more examples.

关键词： integral inequality symmetric polynomial inequality Timofte’s dimension-decreasing method successive difference substitution mechanical decision inequality-proving package BOTTEMA

Design of a 400 N and 12 mm Mechanical Air Gap High Temperature Superconducting Linear Synchronous Motor

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稀有金属材料与工程 2011年第S3期40卷 319-321页

作者： Yen Fei1,2,3, Li Jing1,2,3, Zheng Shijun1,2,3, Jiang Donghui1,2,3, Liu Lu1,2,3, Liu Wei1,2,3, Ma Guangtong1,2,3, Wang Jiasu1,3, Wang Suyu1,3 1 Applied Superconductivity laboratory, Southwest Jiaotong University, chengdu 610031, china 2 State key laboratory of Traction Power, Southwest Jiaotong University, chengdu 610031, china 3 national laboratory for Rail Transit, chengdu 610031, china SW Jiaotong Univ Appl Superconduct Lab Chengdu 610031 Peoples R China SW Jiaotong Univ State Key Lab Tract Power Chengdu 610031 Peoples R China Natl Lab Rail Transit Chengdu 610031 Peoples R China

The static thrust output on a superconducting coated conductor coil at different excitation and alternating current suspended above a three phase alternating current long-stator comprised of copper coils is presented. Excitation current up to 45 A was applied through the superconducting coil acting as the excitation system of the superconducting linear synchronous motor (SLSM), alternating current up to 9 A was applied to the armature and magnetic air gaps of 10 and 15 mm were investigated for four different cases; coreless, with an iron core or yoke and both a core and yoke. By scaling up and converting the studied superconducting single pancake racetrack coil into a double pancake coil and connecting four of such coils in series, an SLSM prototype capable of generating 400 N of thrust output and 1 kW of power output with a 12 mm mechanical air gap operating at 77 K is proposed.

关键词： high temperature superconductivity linear synchronous motor long stator motor superconducting coil force measurements

Second mode unstable disturbance measurement of hypersonic boundary layer on cone by wavelet transform

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Acta Mechanica Sinica 2011年第4期27卷 488-493页

作者： Jian Han.Nan Jiang.Yan Tian Department of Mathematics,Tianjin University,300072 Tianjin,china Department of Mechanics,Tianjin University,300072 Tianjin,china Tianjin key laboratory of modern Engineering Mechanics,300072 Tianjin,china State key laboratory of Nonlinear Mechanics,Institute of Mechanics,Chinese Academy of Sciences,100190 Beijing,china Department of Mathematics Tianjin University Tianjin China Department of Mechanics Tianjin University Tianjin China Tianjin key laboratory of modern Engineering Mechanics Tianjin China State key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing China

Experimental investigation of hypersonic boundary layer instability on a cone is performed at Mach number 6 in a hypersonic wind tunnel. Time series signals of instantaneous fluctuating surface-thermal-flux are measured by Pt-thin-film thermocouple temperature sensors mounted at 28 stations on the cone surface in the streamwise direction to investigate the development of the unstable disturbance. Wavelet transform is employed as a mathematical tool to obtain the multi-scale characteristics of fluctuating surfacethermal-flux both in the temporal and spectrum space. The conditional sampling algorithm using wavelet coefficient as an index is put forward to extract the unstable disturbance waveform from the fluctuating surface-thermal-flux *** generic waveform for the second mode unstable disturbance is obtained by a phase-averaging technique. The development of the unstable disturbance in the streamwise direction is assessed both in the temporal and spectrum space. Our study shows that the local unstable disturbance detection method based on wavelet transformation offers an alternative powerful tool in studying the hypersonic unstable mode of laminar-turbulent transition. It is demonstrated that, at hypersonic speeds, the dominant flow instability is the second mode, which governs the course of laminar-turbulent transition of sharp cone boundary layer.

关键词： Hypersonic boundary layer. Sharp cone Insta-bility Wavelet transform

Tissue Response of an Osteoinductive Bioceramic in Bone Defect Rabbit Model

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 28-31页

作者：程丽佳步宏 key laboratory of Transplant Engineering and Immunology Ministry of HealthWest China HospitalSichuan University Department of Pathology West China HospitalSichuan University

HA/TCP and HA rods （φ5 mm×10 mm） were made for implantation in New Zealand white rabbit with different condition. Sixty three rabbit were divided into three groups： group 1 （n=18）, group 2 （n=27） and group 3 （n=18）. In group 1, 10 mm radius was defected, and one HA/TCP rod was implanted in the muscle a distant away from the bone defect area. In group 2, also, 10 mm radius was defected, one HA rod was implanted in the muscle a distant away from the bone defect area. In group 3, two HA/TCP rods were implanted in the dorsal muscle of the rabbit with bone intact. Histological observation showed that in group 1, some new bone was found only two months after implantation （n=2）, and obvious immature woven bone could be observed in these bioceramics from the 3rd month on. However, in group 3, bone began to be found 6 months after implantation （n=2）. In group 2, we could not find any bone tissue up to 9 month’s observation. These results suggest that, first, the bone defect model could significantly accelerate bone formation at non-osseous sites in rabbits; second,. HA/TCP bioceramics were confirmed with osteoinductive property while HA bioceramics without osteoinductive property nearly. Thus, bone defect might be a good animal model for further researches for osteoinductive bioceramics.

关键词： HA/TCP osteoinduction animal model

Kinetic model of transesterification of diphenyl carbonate and 1,4-butyldiol

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Journal of Natural Gas Chemistry 2010年第4期19卷 436-440页

作者： Liping Wang1,2,3,4,Bin Xiao1,2,4,Gongying Wang1,2 1.chengdu Institute of Organic Chemistry,Chinese Academy of Science,chengdu 610041,Sichuan,china 2.Changzhou key laboratory of Green and Technology,Changzhou Institute of Chemistry,Changzhou 213164,Jiangsu,china 3.Department of Chemistry,Qujing Normal College,Qujing 655000,Yunnan,china 4.Graduate School of Chinese Academy of Science,Beijing 100039,china [a] chengdu Institute of Organic Chemistry Chinese Academy of Science Chengdu 610041 Sichuan China [b] Changzhou Key Laboratory of Green and Technology Changzhou Institute of Chemistry Changzhou 213164 Jiangsu China [c] Department of Chemistry Qujing Normal College Qujing 655000 Yunnan China [d] Graduate School of Chinese Academy of Science Beijing 100039 China

The transesterification of diphenyl carbonate （DPC） with 1,4-butyldiol （BD） was kinetically investigated in the presence of lithium acetate catalyst at 465 *** reaction was followed by the measurement of the quantity of phenol which was distilled from the *** experiments supported the assumption that the phenyl ester groups in DPC and phenyl hdroxybutyl carbonate （PHBH） had the same reactivity,and the transesterification obeyed first-order kinetics with respect to DPC and BD,and a rate equation was *** reaction rate was found to be first order with respect to the catalyst concentration as *** those data were incorporated in the rate equation,excellent agreement between calculated values and the observed ones was recognized over a wide range.

关键词： transesterification diphenyl carbonate 1,4-butyldiol lithium acetate kinetics

Some open problems in granular matter mechanics

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Progress in Natural Science:Materials International 2009年第5期19卷 523-529页

作者： Qicheng Sun a, Guangqian Wanga, Kaiheng Hub a Department of Hydraulic Engineering, State key laboratory for Hydroscience and Engineering, Tsinghua University, Beijing 100084, china b Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, chengdu 610041, china [a]Department of Hydraulic Engineering State Key Laboratory for Hydroscience and Engineering Tsinghua University Beijing 100084 China [b]Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Granular matter is a large assemblage of solid particles, which is fundamentally different from any other type of matters, such as solid and liquid. Most models presented for granular matter are phenomenological and are only suitable for solving engineering problems. Many fundamental mechanical problems remain open. By analyzing characteristics of internal state structure, we propose that granular matter is intrinsically multiscale, i.e. microscale of particle size, mesoscale of force chain, and macroscale of the bulk of granular matter. The correlations among difference scales would be crucial. The mesoscale force chain network is determined by both particle properties and macroscopic boundary conditions. The evolution of the force the chain network contributes to macroscopic mechanical properties of granular matter. In addition, we discuss the drawbacks in simplifying contact forces in the current models, and the difficulties in analyzing the interaction of interstitial fluid in wet granular matter. As an appropriate application of granular matter, debris flow can be studied with granular matter mechanics; meanwhile, debris flow brings more challenges which certainly motivate future studies on granular matter.

关键词： Granular matter Multiscale mechanics Force chain Contact mechanics Debris flow

Research on the relationship between site function and environment at the site of Zhongba,Chongqing City,china

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Chinese Science Bulletin 2008年第S1期53卷 58-73页

作者： SUN ZhiBin Institute of Cultural Relics and Archaeology of Sichuan Province,chengdu 610041,china 1. Institute of Cultural Relics and Archaeology of Sichuan Province Chengdu 610041 China

The Zhongba site has been demonstrated to be a location of salt production based on multi-disciplinary research including salt archaeology,environmental archaeology,zooarchaeology,paleobotany,and other natural science *** continuity of salt production from the Han Dynasty to the present day as understood primarily from ancient texts can now be traced back to even earlier times. Based on the characteristics of cultural layer deposits,features,and artifacts,Zhongba can be clearly distinguished from known settlements,and from bronze,iron,pottery and porcelain *** to various natural science examinations,the major impurities in local salt brine are also found in floor features,brine troughs,and rounded bottom pots at the site even though NaCl itself was not *** traces were left over from the salt production process rather than being naturally *** and its constituent features and artifacts share many common characters with other salt production sites around the ***,the Zhongba site can be confidently identified as a salt production site where activity continued for several thousand *** formation of the site cannot be separated from salt production,and it is also highly related to its natural environment.

关键词： Zhongba site function salt production environmental relationships

Research on common issues for relationship between mechanism degree of freedom,driving link and executive link

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Science china(Technological Sciences) 2009年第4期52卷 966-974页

作者： WANG AiLun College of Mechanical & Electrical Engineering, Central South University, Changsha 410083, china key laboratory of modern Complex Equipment Design and Extreme Manufacturing, Ministry of Education, Changsha 410083, china 1. College of Mechanical & Electrical Engineering Central South University Changsha 410083 China 2. key laboratory of modern Complex Equipment Design and Extreme Manufacturing Ministry of Education Changsha 410083 China

During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by utilization of bond graph theory. The force-transfer de- gree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utiliza- tion of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer de- gree of freedom is further explored and analyzed. Thus, the relationship between the mechanism de- gree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

关键词： duality bond graph Junction-Structure Equation driving link executive link degree of freedom