检索结果-南通市图书馆

Science China Chemistry 1991年第7期34卷 769-776页

作者：林炳承 E.BAYER V.MUSCHALEK B.KOPPENHOEFER Dalian Institute of Chemical Physics Academia SinicaDalian 116012 PRC Instisut

TFA-Ala-OMe, TFA-Ala-Ala-OMe, and TFA-Ala-Ala-Ala-OMe can be separated into 1, 2, and 4 enantiomeric pairs, respectively, by GC on the chiral stationary phase Chirasil-Val. The selectivity of the chiral stationary phase for the different stereoisomers is controlled by both interaction enthalpy and interaction entropy. The interaction enthalpy is approximately proportional to the number of Ala units. Although the whole molecule is involved in the interaction, the C-terminus plays an important role. The elution order of DDD- and LLL-TFA-Ala-Ala-Ala-OMe is opposite to the order of the enhalpy values, and the ratio of net retention data t’r(DDD)/t’r(LLL) is increased with increasing temperature. By lowering the temperature, peak crossing of the enantiomeric pair has been observed. Below the isoselective temperature Tiso’ the order of elution is ruled by the enthalpy of interaction, above Tiso by the entropy of interaction.

关键词： gas chromatography enantiomer resolution oligopeptides Chirasil-Val thermodynamic analysis reversal of peak order.

thermodynamic CALCULATION WITH MODELS FOR LIQUID COPPER

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1994年第2期4卷 25-28页

作者： Ding,Xueyong Wang,Wenzhong Gou,Den(Department of Ferrous Metallurgy, Northeastern University, Shenyang 110006)Han,Qiyong(Department of Physical Chemistry, University of Science & Technology Beijing,Beijing 100083)

ＴＨＥＲＭＯＤＹＮＡＭＩＣＣＡＬＣＵＬＡＴＩＯＮＷＩＴＨＭＯＤＥＬＳＦＯＲＬＩＱＵＩＤＣＯＰＰＥＲＤｉｎｇ，Ｘｕｅｙｏｎｇ；Ｗａｎｇ，Ｗｅｎｚｈｏｎｇ；Ｇｏｕ，ＤｅｎＴＨＥＲＭＯＤＹＮＡＭＩＣＣＡＬＣＵＬＡＴＩＯＮＷ... 详细信息

ＴＨＥＲＭＯＤＹＮＡＭＩＣＣＡＬＣＵＬＡＴＩＯＮＷＩＴＨＭＯＤＥＬＳＦＯＲＬＩＱＵＩＤＣＯＰＰＥＲＤｉｎｇ，Ｘｕｅｙｏｎｇ；Ｗａｎｇ，Ｗｅｎｚｈｏｎｇ；Ｇｏｕ，ＤｅｎＴＨＥＲＭＯＤＹＮＡＭＩＣＣＡＬＣＵＬＡＴＩＯＮＷＩＴＨＭＯＤＥＬＳＦＯＲＬＩＱＵＩ...

关键词： liquid Cu interaction parameter thermodynamic calculation

thermodynamic PROPERTIES OF Al-Ce-Pb(or Sn) LIQUID SOLUTIONS

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1993年第3期3卷 27-28,51页

作者： Sun, Yunyong Du, Ting Central Iron and Steel Research Institute, Beijing 100081, China

thermodynamic properties of Al-Ce-Pb and Al-Ce-Sn liquid systems were studied by direct equilibrium method at 800℃. The results obtained include: equilibrium products, their standard Gibbs energies of formation, equi... 详细信息

关键词： aluminum-base solutions cerium lead tin thermodynamic properties

Sampling lattices in semi-grand canonical ensemble with autoregressive machine learning

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 588-597页

作者： James Damewood Daniel Schwalbe-Koda Rafael Gómez-Bombarelli Department of Materials Science and Engineering Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02319USA

Calculating thermodynamic potentials and observables efficiently and accurately is key for the application of statistical mechanics simulations to materials science.However,naive Monte Carlo approaches,on which such calculations are often dependent,struggle to scale to complex materials in many state-of-the-art disciplines such as the design of high entropy alloys or multi-component catalysts.To address this issue,we adapt sampling tools built upon machine learning-based generative modeling to the materials space by transforming them into the semi-grand canonical ensemble.Furthermore,we show that the resulting models are transferable across wide ranges of thermodynamic conditions and can be implemented with any internal energy model U,allowing integration into many existing materials workflows.We demonstrate the applicability of this approach to the simulation of benchmark systems (AgPd,CuAu) that exhibit diverse thermodynamic behavior in their phase diagrams.Finally,we discuss remaining challenges in model development and promising research directions for future improvements.

关键词： canonical thermodynamic directions

IMPROVEMENT　OF　THE　O－P　thermodynamic　MODEL　OF　THERMOELASTIC　MARTENSITIC　TRANSFORMATION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1995年第2期5卷 55-60页

作者： Yang, Guanjun Hao, Shiming Northwest Inst for Nonferrous Metal Research Baoji China

ＩＭＰＲＯＶＥＭＥＮＴＯＦＴＨＥＯ－ＰＴＨＥＲＭＯＤＹＮＡＭＩＣＭＯＤＥＬＯＦＴＨＥＲＭＯＥＬＡＳＴＩＣＭＡＲＴＥＮＳＩＴＩＣＴＲＡＮＳＦＯＲＭＡＴＩＯＮ￥Ｙａｎｇ，Ｇｕａｎｊｕｎｔ；Ｈａｏ，Ｓｈｉｍｉｎｇ（Ｎｏｒｔ... 详细信息

ＩＭＰＲＯＶＥＭＥＮＴＯＦＴＨＥＯ－ＰＴＨＥＲＭＯＤＹＮＡＭＩＣＭＯＤＥＬＯＦＴＨＥＲＭＯＥＬＡＳＴＩＣＭＡＲＴＥＮＳＩＴＩＣＴＲＡＮＳＦＯＲＭＡＴＩＯＮ￥Ｙａｎｇ，Ｇｕａｎｊｕｎｔ；Ｈａｏ，Ｓｈｉｍｉｎｇ（ＮｏｒｔｈｗｅｓｔＩｎｓｔｉｔｕｔｅｆｏｒ...

关键词： thermoelastic martensitic transformation thermodynamic model calorimetric experiment

Study of thermodynamic Properties of Nonstoichiometric Phase with Compound Energy Model

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2002年第5期18卷 422-426页

作者： ShuigenHUANG LinLI O.V.D.Biest J.Vleugels PeilingWANG Sch. of Mat. Sci. and Eng. Shanghai Univ. Shanghai 200072 China Dept. MTM Katholieke Univ. Leuven B-3001 Heverlee Belgium Shanghai Inst. of Ceramics Chinese Acad. of Sci. Shanghai 200050 China

Using compound energy model (CEM), the thermodynamic properties of and were evaluated. The evaluation was based on the optimization of ZrIO2-CeO2 and ZrO2-CeO1.5 systems, as well as the miscibility gap in CeO1.5-CeO2 system. Except the cubic fluorite structure phase assessed with compound energy model, all the other solution phases were assessed with subsitutional solution model. The model parameters were evaluated through fitting the selected experimental data by means of thermodynamic optimization. A set of parameters with thermodynamics self-consistency was obtained and satisfactorily described the complex relation between y in and the partial pressure of oxygen at different temperatures, also the interdependence among miscellaneous factors such as temperature, oxygen partial pressure, the reduction amount of CeO2 as well as the nonstoichiometry in cubic phase - The calculated results seem to be reasonable when put into the explanation of pressureless sintering of Ce02-stabilized ZrO2 powder compacts at a controlled oxygen partial pressure.

关键词： Zirconia Ceria Nonstoichiometry thermodynamic

Denaturation behavior of inclusions in industrial pure iron by calcium treatment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2023年第2期30卷 249-258页

作者： Xin Liu Yan-ping Bao Cheng-jian Hua Jian-hua Chu Chao Gu Min Wang State Key Lab of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China

Only a few Chinese enterprises can produce high-quality industrial pure iron,and studies on the smelting process of industrial pure iron were limited.The inclusions in a melting process were characterized by means of electron microscopy and an automatic inclusion analysis system,and the evolution mechanism of inclusion was studied using thermodynamic calculation to optimize the calcium alloy addition in liquid window.The results show that during the smelting process,inclusions mainly composed of Al_(2)O_(3)and spinel are formed before calcium treatment.After calcium treatment,they continuously react with[Ca],[S]and[Ti],grow up,and are removed during refining and tundish pouring.In the end,there are more small-sized inclusions containing CaS,and the contents of Al_(2)O_(3)and spinel are less.According to thermodynamic calculations,the appropriate calcium treatment liquid window for the molten steel composition is(10-38)×10^(-6).Calcium treatment has changed the main types of inclusions in industrial pure iron from Al_(2)O_(3)to small-sized inclusions containing CaS and effectively reduces the influence of Al_(2)O_(3)inclusions on the quality of industrial pure iron.

关键词： Industrial pure iron Calcium treatment Inclusion thermodynamic CaS

Determination of thermodynamic Parameters of Some Fluorochlorohydrocarbons in Acetone by Gas Chromatography at Low Temperature and Pressurization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 1998年第2期6卷 84-92页

作者：王丽华 Department of Chemical Engineering Zhejiang University

1 INTRODUCTIONGas chromatography(GC)has been proved to perform satisfactorily in vapor-liquid equilib-rium measurements and in the study of solution theory.Infinite dilution data are useful notonly for design calculations but also for theoretical development of correlations.Studies inthis field have been carried on at the Zhejiang University.

关键词： low temperature pressurization chromatography fluorochlorohydrocarbons thermodynamic parameters

Thermochemical decomposition of phosphogypsum with Fe-P slag via a solid-state reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第7期35卷 113-119页

作者： Lei Sun Zhongjun Zhao Xiushan Yang Yan Sun Quande Li Chunhui Luo Qiang Zhao School of Chemical Engineering Sichuan UniversityChengdu 610065China School of Mechanical Engineering Chengdu UniversityChengdu 610106China State Key Laboratory of Long-Life High Temperature Materials Deyang 618000China Dongfang Electric Corporation Dongfang Turbine Co. LtdDeyang 618000China

Phosphogypsum is a solid waste sourced from the wet-process phosphoric acid industry,which causes severe environmental damages.Its utilization was limited by its high decomposition temperature and high energy consumption.Herein,an Fe-P slag,which is a solid waste that mainly comprises iron phosphide(FeP)and diiron phosphide(Fe_(2)P),can dramatically decrease the decomposition temperature of phosphogypsum.It was found that the Fe-P slag and CaSO_(4) can react as shown in the following reaction equation:2Fe_(1.5)P+3CaSO_(4)+6CO_(2)→Ca_(3)(PO_(4))_(2)+Fe_(3)O_(4)+3SO_(2)+6CO.Its reaction mechanism was further determined using the thermodynamic method.It was found that CaS was the key intermediate for this reaction.The CaSO_(4) conversion for this method can reach approximately 97%under the optimized roasting conditions:the molar ratio between Fe_(1.5) P and CaSO_(4) of 2:3,roasting temperature of 900℃,a roasting time of 8 h.

关键词： Phosphogypsum Decomposition Mechanism thermodynamic Roasting conditions

Effect of the projector augmented wave potentials on the simulation of thermodynamic properties of vanadium

在线全文

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2021年第6期6卷 86-93页

作者： Tingting Zhang Yuechao Wang Jiawei Xian Shuaichuang Wang Jun Fang Suqing Duan Xingyu Gao Haifeng Song Haifeng Liu Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100094China

We report significant differences in high-pressure properties of vanadium at zero temperature and finite temperature when different projector augmented wave(PAW)potentials are used in simulations based on density functional theory.When a PAW potential with only five electrons taken as valence electrons is used,the cold pressures in the high-pressure region are seriously underestimated,and an abnormality occurs in the melting curve of vanadium at about 400 GPa.We show that the reason for these discrepancies lies in the differences in the descriptions of the interatomic force,electron dispersion,and anisotropy of electron bonding obtained from differentPAWpotentials at high pressure,which lead to striking differences in the mechanical stability of the system.We propose a procedure for selecting PAW potentials suitable for simulations at high temperature and high pressure.Our results provide valuable guidance for future simulations of thermodynamic properties under extreme conditions.

关键词： vanadium thermodynamic wave