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Chinese Journal of Polymer Science 2019年第6期37卷 617-626页

作者： Yu-Jie Wang Su-Ying Yan Zhi-Ping Zhao Zhen-Yu Xi School of Chemistry and Chemical Engineering Beijing Institute of Technology Environmental Protection Research Institute Beijing Research Institute of Chemical IndustrySINOPEC

The growing demand for non-toxic solvents for membrane preparation has motivated the studies for green and sustainable alternatives of solvents. The effect of droplet isothermal growth within the liquid-liquid phase separation region on isothermal spherulitic growth rate of isotactic polypropylene(iPP) was investigated. The results showed that the droplets grew up at a rate of 0.0172 μm·s^(-1). The larger droplets slowed down the isothermal spherulitic growth rate of iPP. Higher mass ratio of carnauba wax(Cwax)/soybean oil(SO)resulted in faster droplet growth due to weak interaction with polymers. The isothermal crystallization behaviors of iPP in environmentfriendly binary diluents consisting of Cwax and SO mixture were further investigated experimentally using polarized optical *** was demonstrated that the isothermal spherulitic growth rate of iPP in diluents decreased nonlinearly with the increasing crystallization temperature. Compared with virgin iPP, isothermal spherulitic growth rate of iPP in SO diluent was significantly slowed down. The spherulitic growth was further retarded after the addition of Cwax in mixed diluents, resulting in a lower crystallization rate than that in SO. Moreover, the crystal form of iPP membranes was found to be α type through the characterization of small angle X-ray scattering and wide angle X-ray diffraction.

关键词： Isotactic polypropylene Carnauba wax isothermal crystallization kinetics PP membrane

isothermal reduction kinetics of Panzhihua ilmenite concentrate under 30vol% CO–70vol% N2 atmosphere

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International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 240-248页

作者： Ying-yi Zhang Wei Lü Xue-wei Lü Sheng-ping Li Chen-guang Bai Bing Song Ke-xi Han College of Materials Science and Engineering Chongqing University Chongqing 400044 China Panzhihua Iron and Steel Research Institute Panzhihua 617000 China

The reduction of ilmenite concentrate in 30vol% CO–70vol% N_2 atmosphere was characterized by thermogravimetric and differential thermogravimetric(TG–DTG) analysis methods at temperatures from 1073 to 1223 *** isothermal reduction results show that the reduction process comprised two stages;the corresponding apparent activation energy was obtained by the iso-conversional and model-fitting *** the first stage,the effect of temperature on the conversion degree was not obvious,the phase boundary chemical reaction was the controlling step,with an apparent activation energy of 15.55–40.71 k J·mol^(–1).For the second stage,when the temperatures was greater than 1123 K,the reaction rate and the conversion degree increased sharply with increasing temperature,and random nucleation and subsequent growth were the controlling steps,with an apparent activation energy ranging from 182.33 to 195.95 k J·mol^(–1).For the whole reduction process,the average activation energy and pre-exponential factor were 98.94^(–1)18.33 k J·mol^(–1) and 1.820^(–1).816 min^(–1),respectively.

关键词： ilmenite isothermal reduction kinetics carbon monoxide

isothermal PRECISION FORGING PROCESS OF ALUMINUM ALLOY CYLINDRICAL HOUSING

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中国有色金属学会会刊：英文版 1997年第3期7卷 124-127页

作者： Wang, Z Xue, KM Shan, DB Xu, FC Lu, Y HARBIN INST TECHNOL SCH MAT SCI & ENGNHARBIN 150001PEOPLES R CHINA

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ＩＳＯＴＨＥＲＭＡＬＰＲＥＣＩＳＩＯＮＦＯＲＧＩＮＧＰＲＯＣＥＳＳＯＦＡＬＵＭＩＮＵＭＡＬＬＯＹＣＹＬＩＮＤＲＩＣＡＬＨＯＵＳＩＮＧ①ＷａｎｇＺｈｅｎ，ＸｕｅＫｅｍｉｎ，ＳｈａｎＤｅｂｉｎ，ＸｕＦｕｃｈａｎｇ，ＬｕＹａｎＳｃｈｏｏｌｏｆＭａｔｅｒｉａ...

关键词： aluminum alloy isothermal precision forging assembled die heating range

isothermal Microcalorimetry:A Review of Applications in Soil and Environmental Sciences

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Pedosphere 2007年第2期17卷 137-145页

作者： RONG Xing-Min HUANG Qiao-Yun JIANG Dai-Hua CAI Peng LIANG Wei Key Laboratory of Subtropical Agricultural Resources and Environment Ministry of Agriculture Huazhong Agricultural University Wuhan 430070 （China）

isothermal microcalorimetry provides thermodynamic and kinetic information on various reactions and processes and is thereby a powerful tool to elucidate their mechanisms. Certain improvement in isothermal microcalorimetry with regard to the studies on soil and environmental sciences is briefly described. This review mainly focuses on the use of microcalorimetry in the determination of soil microbial activity, monitoring the toxicity and biodegradation of soil organic pollutants, the risk evaluation of metals and metalloids, the heat effect of ion exchange and adsorption in soil, and environmental researches. Promising prospects for the applications of the technique in the field are also discussed.

关键词： environment isothermal microbial activity microcalorimetry soil

The kinetic of mass loss of grades A and B of melted TNT by isothermal and non-isothermal gravimetric methods

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Defence Technology（防务技术） 2018年第2期14卷 126-131页

作者： Hamid Reza Pouretedal Sajjad Damiri Parvaneh Nosrati Ehsan Forati Ghaemi Faculty of Applied Chemistry Malek-ashtar University of Technology

The kintic and activation energy of mass loss of two grades of melted TNT explosive, grade A and grade B, with freezing points of 80.57 and 78.15 ℃, respectively, were studied by isothermal and nonisothermal gravimetric methods. In isothermal method, the mass loss of samples in containers of glass and aluminum was followed in temperatures of 80, 90 and 100 ℃. The kinetic of the mass loss of the samples in the aluminum container was higher than the kinetic of it in the glass container that can be related to the effects of heat transfer and catalytic of aluminm metal. Also, the presence of impurities in grade B was due to increasing of kinetic of mass loss of it versus grade A. The non-isothermal curves were obtained in range of 30-330 ℃ at heating rates of 10,15 and 20 ℃·min^(-1).The TG/DTG data were used for determination of activation energy(E_a) of mass loss of TNT samples upon degradation by using Ozawa, Kissinger, Ozawa-Flynn-Wall(OFW) and Kissinger-Akahira-Sunose(KAS) methods as model free methods. The activation energies of grades of A and B of TNT was obtained 99-120 and 66-70 kJ mol^(-1)respectively. The lower values of activation energy of the degradation reaction of grade B confirm the effect of impurities in the kinetics of mass loss of this grade.

关键词： TNT isothermal Non-isothermal Kinetic Mass loss

Kinetics and microstructural modeling of isothermal austenite-to-ferrite transformation in Fe-C-Mn-Si steels

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Journal of Materials Science & Technology 2019年第8期35卷 1753-1766页

作者： S.J.Song W.K.Che J.B.Zhang L.K.Huang S.Y.Duan F.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical University

During the multi-stage processing of advanced high-strength steels, the austenite-to-ferrite transformation, generally as a precursor of the formation of other non-equilibrium or metastable structures, has a severe effect on the subsequent phase transformations. Herein, a more flexible kinetic and microstructural predictive modeling for the key austenite-to-ferrite transformation of Fe-C-Mn-Si steels was developed,in combination with the classical nucleation theory, the general mixed-mode growth model based on Gibbs energy balance, the microstructural path method and the kinetic framework for grain boundary nucleation. Adopting a bounded, extended matrix space corresponding to a single ferrite grain, both softimpingement and hard-impingement can be naturally included in the current modeling. Accordingly, this model outputs the ferrite volume fraction, the austenite/ferrite interface area per unit volume, and the average grain size of ferrite, which will serve as the input parameters for modeling the subsequent bainite or martensite transformations. Applying the model, this work successfully predicts the experiment measurement of the isothermal austenite-to-ferrite transformation in Fe-0.17 C-0.91 Mn-1.03 Si(wt%) steel at different temperatures and explains why the final-state average grain size of ferrite has a maximum at the moderate annealing temperature. Effectiveness and advantages of the present model are discussed arising from kinetics and thermodynamics accompanied with nucleation, growth and impingement.

关键词： isothermal austenite-ferrite transformation Kinetics Thermodynamics Microstructural modeling Low-alloy steel

Electric arc furnace dust non-isothermal reduction kinetics

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中国有色金属学会会刊：英文版 2000年第4期10卷 524-530页

作者：张传福彭兵彭及 Cent S Univ Technol Dept Met Sci & Engn Changsha 410083 Peoples R China McGill Univ Dept Engn Met Montreal PQ H3A 2B2 Canada

Kinetic studies of the electric arc furnace (EAF) dust reduction process have been carried out under non isothermal temperature condition. EAF dust pellets were made with carbon as the reducing agent and dolomite as the binder. A Thermo Gravimetric Analyzer (TGA) was used to determine the mass loss of pellets, which were heated at an average rate of 40 K/min up to 1 500 ℃. The reduction degree was calculated by consideration of the pellet mass loss, evaporation of moisture, dust, zinc and lead at high temperature. The reduction process of EAF dust was divided into three steps related to the change in temperature and time. The non isothermal reduction kinetics equations were set up to describe every step. The kinetics parameters such as apparent activation energies and frequency factors were established at the same time. It was found that the first step is chemically controlled, the second step is diffusion controlled and the third step is strongly dependent on the initial content of carbon in the pellet. CrO can be reduced only in the last step by high temperature and high initial carbon content.

关键词： EAF dust recycles chemical kinetics non isothermal reduction

Microstructural evolution of Mg9AlZnY alloy with vibration in lost foam casting during semi-solid isothermal heat treatment

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中国有色金属学会会刊：英文版 2010年第S3期20卷 768-773页

作者：赵忠樊自田蒋文明董选普 State Key Laboratory of Material Processing and Die & Mould Technology Huazhong University of Science and Technology

The nearly equiaxed grains of Mg9AlZnY alloy were obtained by vibrating solidification in lost foam casting(LFC) and the microstructure of Mg9AlZnY alloy was *** this basis,the morphology and size of α-Mg grains fabricated by semi-solid isothermal heat treatment(SSIT) at 530 ℃ and 570 ℃ holding different time were *** results show that the main constituent phases of Mg9AlZnY alloy are α-Mg,β-Mg17Al12 and Al2Y,and the Y can greatly refine α-Mg *** distribution of α-Mg grains equivalent diameters between 20 and 100 μm is up to 87%,and the average roundness of α-Mg grains reaches 1.37 in the specimen obtained at 570 ℃ and holding time 60 *** to the analysis of solidification kinetics and thermodynamic,binary eutectic with low melting point melts firstly on SSIT *** the liquid fraction increases with the solute diffusibility,both of the shape and size of α-Mg grains change *** the liquid fraction reaches equilibrium,the α-Mg grains are gradually spheroidized under the interfacial tension,and then the α-Mg grains begin to combine and *** of α-Mg dendritic grains on SSIT process is obviously different from that of equiaxed grains.

关键词： lost foam casting(LFC) semi-solid isothermal heat treatment(SSIT) microstructural evolution magnesium alloy

Advancing optothermal manipulation:decoupling temperature and flow fields in quasi-isothermal microscale streaming

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Light(Science & Applications) 2023年第9期12卷 1713-1714页

作者： Youngsun Kim Yuebing Zheng Materials Science and Engineering Program and Texas Materials Institute The University of Texas at AustinAustinTX78712USA Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX78712USA

By decoupling temperature and flow fields through symmetry-correlated laser scan sequences,ISO-FLUCS enables quasi-isothermal optofluidic microscale *** technique offers precise control over fluid manipulation while m... 详细信息

关键词： thermal isothermal flow

GLOBAL INSTABILITY OF MULTI-DIMENSIONAL PLANE SHOCKS FOR isothermal FLOW

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Acta Mathematica Scientia 2022年第3期42卷 887-902页

作者： Ning-An LAI Wei XIANG Yi ZHOU College of Mathematics and Computer Science Zhejiang Normal UniversityJinhua 321004China Department of MathematicsLishui UniversityLishui 323000China Department of Mathematics City University of Hong KongKowloonHong Kong 999077China School of Mathematical Sciences Fudan UniversityShanghai 200433China

In this paper,we are concerned with the long time behavior of the piecewise smooth solutions to the generalized Riemann problem governed by the compressible isothermal Euler equations in two and three dimensions.A non-existence result is established for the fan-shaped wave structure solution,including two shocks and one contact discontinuity which is a perturbation of plane ***,unlike in the one-dimensional case,the multi-dimensional plane shocks are not stable ***,a sharp lifespan estimate is established which is the same as the lifespan estimate for the nonlinear wave equations in both two and three space dimensions.

关键词： Blow-up global solution instability shock contact disctinuity Euler equations isothermal generalized Riemann problem nonlinear wave equations