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A Study of a Molecular Mechanics Field Used in Simulating Enantiorecognition

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Chinese chemical letters 1999年第5期10卷 415-418页

作者： He Qing SHEN Qing Hat WANG Dao Qian ZHU liang Mo ZHOU(dalian institute of chemical Physic. Chinese Academy of Sciences. dalian 116012) Chinese Acad Sci Dalian Inst Chem Phys Dalian 116012 Peoples R China

A molecular mechanics field, Alchemy II, was utilized to model the chiral recognition between S-N-acetyl-alpha-methyl-alpha-naphthylamine and (R, S)-N-(3, 5-dinitrophrnyl)-alpha-methyl-benzeneacetamide and between beta-cyclodextrin and (R, S)-fenoprofen. Some preliminary results have: been obtained to sustain the three-point action models and the induce-fit action in enantiorecognition.

关键词： molecular mechanics simulating enantiorecognition

Online diagnosis of electron excitation temperature in CH_4+H_2 discharge plasma at atmospheric pressure by optical emission spectra

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Science China(Physics,Mechanics & Astronomy) 2008年第12期51卷 1892-1896页

作者： CUI JinHua1, XU ZhenFeng2, ZHANG Jialiang3↑, NIE QiuYue3, XU GenHui4 & REN longliang5 1 Faculty of Chemistry and chemical engineering, liaoning Normal University, dalian 116021, China 2 Technique Center for Modern Education, liaodong college, Dandong 126709, China 3 State Key laboratory for Materials Modification by laser, Ion and Electron Beams, dalian University of technology, dalian 116023, China 4 college of chemical engineering, Tianjin University, Tianjin 300072, China 5 Department of Physics, Science college, Tianjin University, Tianjin 300072, China 1. Faculty of Chemistry and chemical engineering Liaoning Normal University Dalian 116021 China 2. Technique Center for Modern Education Liaodong College Dandong 126709 China 3. State Key laboratory for Materials Modification by laser Ion and Electron Beams Dalian University of Technology Dalian 116023 China 4. college of chemical engineering Tianjin University Tianjin 300072 China 5. Department of Physics Science College Tianjin University Tianjin 300072 China

Methane coupling under low temperature plasmas at atmospheric pressure is a green process by use of renewable sources of energy. In this study, CH4+H2 dis- charge plasma was on-line diagnosed by optical emission spectra so as to char- acterize the discharge system and to do spade work for the optimization of the technical parameters for future commercial production of methane coupling under plasmas. The study was focused on a calculation method for the online diagnosis of the electron excitation temperature in CH4+H2 discharge plasma at atmospheric pressure. The diagnostic method is easy, efficient and fairly precise. A serious er- ror in a literature was corrected during the reasoning of its series of equations formerly used to calculate electron temperatures in plasmas.

关键词： low temperature plasma electron excitation temperature optical emission spectrum online diagnosis

Catalytically generated noncovalent ammonium dienolate:a versatile platform for the development of organocatalytic asymmetric cascade reactions

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Science China Chemistry 2024年第8期67卷 2524-2546页

作者： Jun-bing lin Dong-Sheng Ji Peng-Fei Xu State Key laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Shaanxi Key laboratory of chemical Reaction engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China

Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.

关键词： organocatalysis asymmetric catalysis ammonium dienolate cascade reaction difunctionalization

A NOVEl REDUCTIVE TETRAAllYlATION OF PYRIDINE

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Chinese chemical letters 1995年第10期6卷 833-834页

作者： Xian Mou ZENG Jia Qiang CAI and Yi Jian GU(dalian institute of chemical Physics, Academia Sinica 161 Zhongshan Rcad dalian 116012) Acad Sinica Dalian Inst Chem Phys Dalian 116012 Peoples R China

Pyridine and 4-picoline undergo reductive tetraallylation with allyl bromide and zinc dust in THF at room temperature to afford regio-selectively 1,2,3,6-tetraallyl-1,2,3,6-tetrahydropyridine and 1,2,3,6-tetraallyl-1,...

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On-line parallel reversed phase two-dimensional liquid chromatography for high-throughput analysis of complex proteomic samples

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Science China Chemistry 2006年第6期49卷 527-533页

作者： WANG Zhicong1,3, ZHANG Qinghe2, lI Tong2, ZHAO Zhongyi3 & ZHANG Weibing1 1. dalian institute of chemical Physics, Chinese Academy of Sciences, dalian 116011, China 2. dalian Elite Analytical Instrument Co., ltd., dalian 116011, China 3. Faculty of Material Science and chemical engineering, China University of Geosciences, Wuhan 430074, China 1. dalian institute of chemical Physics Chinese Academy of Sciences Dalian 116011 China 3. Faculty of Material Science and chemical engineering China University of Geosciences Wuhan 430074 China 2. dalian Elite Analytical Instrument Co. Ltd. Dalian 116011 China

A comprehensive two-dimensional liquid chromatographic system (2D SCX/RP) is con- structed with a 10-port-2-way valve using strong cation exchange chromatography (Hypersil SCX, 100 mm×4.6 mm I.D.) followed by reversed phase chromatography (Hypersil BDS C18, 15 mm×4.6 mm I.D.) to separate the complex peptides from globin peptic hydrolysate. After the sample was loaded on the SCX column, the phosphate buffer (pH 4.0) was used to elute the peptides. Then, elutes flowed through the interface and the peptides focused on the head of the trapping columns (Hypersil BDS C18, 15 mm×4.6 mm I.D.) but salt passed into the waste. After the valve was switched, the samples were flushed with a backward flow into the RP analytical column. The peptides on the SCX were eluted with 12 discontinuous steps linearly increasing salt concentrations. The peptides enriched on the trapping column were desalted and separated by the RP columns. The resolution and the resolved peaks of the 2D SCX/RP system were greatly increased and the total peak capacity reached as high as 2280.

关键词： two-dimensional liquid chromatography, interface, trapping column, proteomics, globin.

Evaluation of 3D crustal seismic velocity models in southwest China:Model performance,limitation,and prospects

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Science China Earth Sciences 2024年第2期67卷 604-619页

作者： Xin WANG ling CHEN Qi-Fu CHEN Key laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China college of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China State Key laboratory of lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China

Southwest China is a tectonically and seismically active region,witnessing strong deformation due to the collision between the Indian and Eurasian *** the subsurface velocity structure of this region is thus important in understanding the tectonics and geodynamic processes of continental collision and in mitigating seismic *** studies have provided various 3D seismic velocity models in southwest ***,discrepancies exist among these models,and less effort has been made to quantify the reliability and accuracy of these existing velocity *** this study,we use regional 3D waveform simulation to evaluate the performance of various regional crustal 3D velocity models in reproducing observed *** particularly focus on two recent earthquake sequence in the region,the 2021 Yunnan Yangbi MS_(6.4) earthquake sequence and the 2022 Sichuan luding MS_(6.8) earthquake *** tested 3D velocity models include the Southwest China Community Velocity model V1.0,the Unified Seismic Tomography Models for Continental China lithosphere V2.0,the adjoint full waveform tomography model of the crustal and upper mantle beneath Eastern Tibetan Plateau,and the shallow seismic structure model beneath continental *** results show that the tested 3D velocity models generally capture well long-period(ls adequately resolve overall large-scale subsurface ***,the 3D synthetics show discrepancies in higher frequencies(0.05–0.3 Hz)and the performance of the 3D velocity models varies from region to region,suggesting that smaller scale heterogeneities are not well *** shallow velocity structures(llow structures in waveform *** full-waveform tomography model shows a slighter better performance than the other models,especially for the body-waves,highlighting the advantages

关键词： Southwest China Seismic tomography models Shallow Structures Waveform simulation Model evaluation

The prediction of the peak width at half height in HPlC

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Chinese Journal of Chemistry 1991年第3期9卷 237-244页

作者： ZOU,Han-Fa ZHANG,Yu-Kui lU,Pei-Chang dalian Chromatographic R.& D.Center of China dalian institute of chemical Physics,Academia Sinica,dalian 116011 dalian Chromatographic R. & D. Center of China dalian institute of chemical Physics Academia Sinica Dalian 116011

The prediction of the peak width at half height is an important aspect in the optimization of the chromatographic operating *** this paper,a linear relationship,between the peak widths at half height and the retention values with various isocratic elution is *** gradient elution,however,the relationship between the peak widths at half height and the so-called invented retention values that correspond to the mobile phase composition by eluting the solute from the column end is *** believe that there is almost the same band width at half height inside the column (in unit of length)for different *** peak width at half height in the chromatogram(in unit of time)is mainly determined by the capacity factor of the solute when it is eluted front the column *** larger the capacity factor of a solute eluted from the column end,the more slowly will be the solute eluted from the column end and the wider will be the peak width at half *** is possible to predict the peak width at half height in various isocratic and gradient elutions by using this linear relationship.

关键词： The prediction of the peak width at half height in HPlC

Direct Enantiomer Separation of 2-PhenylcyclopropanecarboxylateEsters on Cyclodextrin Derivatives Stationary Phases in GC

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Chinese chemical letters 1999年第11期10卷 933-936页

作者： Meng Yan NIE liang Mo ZHOU Xue liang lIU Qing Hai WANG Dao Qian ZHU(dalian institute of chemical Physics, Chinese Academy of Sciences, dalian 116012) Chinese Acad Sci Dalian Inst Chem Phys Dalian 116012 Peoples R China

Direct enantiomeric separation of all four optical isomers of 2-phenylcyclopropane carboxylate ester was first achieved on each of the three different beta-cyciodextrin chiral stationary phases (CSPs) in GC. Using these CSPs, enantiomeric excess of the products of enantioselective cyclopropanation can be determined directly, conveniently and fast.

关键词： enantiomer separation 2-phenylcyclopropanecarboxylates cyclodextrin

Highly efficient Rod-shape Poly(methacrylic acid-co-styrene-codivinylbenzene)High-performance liquid Chromatographic Column

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Chinese chemical letters 1999年第2期10卷 151-154页

作者： Jin Fang WANG Zi Hui MENG liang Mo ZHOU Qing Hai WANG Dao Qian ZHU(dalian institute of chemical Physics, Chinese Academy of Sciences. dalian 116012) Chinese Acad Sci Dalian Inst Chem Phys Dalian 116012 Peoples R China

A highly efficient copolymer (methacrylic acid - co - styrene - divinylbenzene) in situ making high-performance liquid chromatographic column was prepared and evaluated. The column efficiency calculated in terms of height equivalent to a theoretical plate was 25 mu m and rapid separations of small molecules such as substituted aromatic hydrocarbons and aromatic acids were achieved within five minutes.

关键词： highly efficient column poly(methacrylic acid -co styrene-co-divinylbenzene) in situ column substituted aromatic hydrocarbon aromatic acid