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Relationship Between Differential Interference Angle and Parameter of Experiment in Molecular Beam

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Communications in Theoretical Physics 2006年第2X期46卷 294-296页

作者： li Yong-Qing li Jian ma feng-Cai Department of Physics Liaoning University Shenyang 110036 China

Collisional quantum interference （CQI） was observed in the intramolecular rotational energy transfer in the experiment of the static cell, and the integral interference angles were measured. To observe more precise information, the experiment in the molecular beam should be taken,from which the relationship between the differential interference angle and the scattering angle can be obtained. In this paper, the theoretical model of CQI is described in an atom-diatom system in the condition of the molecular beam, based on the first-Born approximation of time-dependent perturbation theory, taking into accounts the long-range interaction potential. The method of observing and measuring correctly the differential interference angle is presented. The changing tendency of the differential interference angle with the impact parameter and relative velocity is discussed. The changing tendencies of the differential interference angle with the parameter of experiment in the molecular beam, including the impact parameter and the velocity are discussed. This theoretical model is important to understand or perform the experiment in the molecular beam.

关键词： differential interference angle quantum interference rotational energy transfer

Relationship between archaeological sites distribution and environment from 1.15 ma BP to 278 BC in Hubei Province

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Journal of Geographical Sciences 2011年第5期21卷 909-925页

作者： li Lan WU li ZHU Cheng li feng ma Chunmei School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

A total of 1362 archaeological sites from the Paleolithic Age to the Warring States time in Hubei Province increase gradually from west to east and from high land to low *** number of Paleolithic sites with altitude of 50-500 m account for 78% of the whole,while 71%-95% of sites from the Neolithic Age to the Warring States time mainly distribute at the areas of 0-200 *** temporal-spatial distribution of archeological sites in this area is affected by two *** one thing,the human beings of every period need to choose the first or the second terrace as living sites which are near water source and are easy to withstand ***,affecting by the regional tectonic uplift since the Holocene,down cutting of rivers can form new river valley,and lateral erosion and accumulation of river in stable time of tectonic movement can result in increasing of many new ***,the human beings migrated to adapt to the change of terrace location,leading to the sites increase gradually in the lower areas of the central and eastern parts of this *** other things,the temporal-spatial distribution of archeological sites in this area is affected by the climate *** Paleolithic sites mostly distribute in the Hanshui River Valley in northeastern Shiyan,southeast of Jinzhou and east of Jinmen,which is because rivers distributed in higher areas in this *** the Chengbeixi Culture period,the sites are rare in the quondam Paleolithic sites distribution area,but increase obviously along the Yangtze River near the southwest *** spore-pollen record of Dajiuhu Basin indicates that only 23 Chengbeixi cultural sites may be related to more precipitation and flood during the Holocene wet and hot *** Daxi Culture,Qujialing Culture and Shijiahe Culture are corresponding to middle and top of the Dajiuhu spore-pollen Zone Ⅳ,during which the climate is in order as a whole and is propitious to agricultural *** the Qujialing Culture

关键词： Hubei Province the Paleolithic Age to the Warring States time temporal-spatial distribution of archeological sites river landform pollen record environmental evolution

Effect of process parameters on steel tube roundness in straightening process

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Journal of Iron and Steel Research International 2020年第11期27卷 1270-1283页

作者： li-dong ma Yu-kang Du Zhi-juan Meng li-feng ma Zi-jian liu Pei-yu liu Coordinative Innovation Center of Taiyuan Heavy machinery Equipment Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina School of Applied Science Taiyuan University of Science and TechnologyTaiyuan 030024ShanxiChina

The inclined six-roll tube straightener is an important equipment for the finishing *** can not only straighten the steel pipe,but also finish the ovality of the cross *** the actual straightening process,the cross section of the tube is prone to deform,that is,the round ness is not *** flatteni ng displacement is an import a nt parameter to control cross-section forming of *** to the established mechanical model,the analytical calculation equations of the flattening force and the flattening displacement were derived using the energy *** on the finite element simulation data,the ratios of the finite element results of the什attening force to the analytical ones were *** correlation coefficient after fitting is greater than 99%,and the fitting effect is *** flattening experiment was carried out on tubes of different materials and different specifications,and the setting method of the optimal flattening displacement during straightening process was *** the actual straightening process,using this flattening displacement,the ovality of straightened steel tube is less than 0.3%.Therefore,the proposed method can provide a reference for the flattening displacement in the actual straightening process.

关键词： Straightening Tube Energy method Flattening force Flattening displacement Finite element method

Characterization of hot deformation behavior of wear-resistant steel BTWl using processing maps and constitutive equations

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Journal of Iron and Steel Research International 2018年第10期25卷 1054-1061页

作者： Peng-tao liu Qing-xue Huang li-feng ma Tao Wang College of Mechanical Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China Shanxi Provincial Key Laboratory of Metallurgical Equipment Design and Technology Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China Heavy machinery Engineering Research Center of the Ministry Education Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China

In order to predict flow instability of wear-resistant steel BTW1, the hot compressions of wear-resistant steel BTW1 were firstly performed at the temperature of 900-1150 ℃ and at the strain rate of 0.05-15 s-1. Then, the constitutive relation was established based on Arrhenius-type hyperbolic sine equation. The results demonstrated that the flow stress depended on the deformation temperature and strain rate. When the deformation temperature kept constant, the flow stress increased as the strain rate increased. When the strain rate remained constant, the flow stress decreased as the temperature increased. The flow stresses calculated by constitutive equations were in a good agreement with experimental results. The apparent activation energy for deformation in the above processing region was estimated to be 369 kJ tool-1. A processing map could be obtained by the superimposition of an instability map on a power dissipation map. Based on the analysis of processing map and the microstructures, the theological instability regimes of strain rate and temperature for hot deformation of wear-resistant steel BTWl had been identified.

关键词： Wear-resistant steel BTW 1 Processing map Constitutive equation Hot deformation Dynamicrecrystallization

Effect of copper on edge cracking behavior and microstructure of rolled austenitic stainless steel plate

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Journal of Iron and Steel Research International 2022年第2期29卷 281-294页

作者： Guang-hui Zhao Jian Zhang Juan li Hua-ying li Hai-tao liu li-feng ma School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan030024ShanxiChina Shanxi Provincial Key Laboratory of Metallurgical Device Design Theory and Technology Taiyuan030024ShanxiChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

Cu is known to affect the edge cracking characteristics of austenitic stainless steel as it causes *** hot rolling test of four kinds of austenitic stainless steel with different copper content(0,2.42,3.60 and 4.35 wt.%)was carried out to examine the effect of hot rolling cracks on steel containing different copper *** evolution of crack and microstructure was analyzed using the scanning electron microscope,energy-dispersive spectrometer,electron back scattered diffraction and transmission electron *** results showed an upward trend in edge cracking degree when Cu content was 4.35%,and the crack extended from the edge of the steel plate to the middle by about 14 ***,severe oxidation was observed inside the crack by *** the increase in copper content at 1250℃,the content of{110}brass and{112}copper textures *** the content of copper was 4.35%,the decrease was most significant,and{112}copper texture content decreased to only 0.5%.Generally,the textures of 2.42%Cu and 3.60%Cu 304L steel changed little,while a large change in the texture of 4.35%Cu 304L steel was *** conclude,the increase in rolling temperature can prevent edge crack and its propagation effectively.

关键词： Austenitic stainless steel Copper Edge crack Microstructure Ferrite

Modeling study on the flow patterns of gas–liquid flow for fast decarburization during the RH process

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International Journal of Minerals,Metallurgy and materials 2018年第2期25卷 153-163页

作者： Yi-hong li Yan-ping Bao Rui Wang li-feng ma Jian-sheng liu Collaborative Innovation Centre of Taiyuan Heavy machinery Equipment and School of materials Science and Engineering Taiyuan University of Science and Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of materials Science and Engineering North University of China

A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.

关键词： modeling study flow pattern vacuum chamber residence time decarburization RH process

Microstructural evolution and mechanical properties of aging high nitrogen austenitic stainless steels

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International Journal of Minerals,Metallurgy and materials 2010年第6期17卷 729-736页

作者： Zhou-hua Jiang Zu-rui Zhang Hua-bing li Zhen li Qi-feng ma School of materials and Metallurgy Northeastern University Shenyang 110819 China

The microstructural evolution of 18Crl 8Mn2Mo0.77N high nitrogen austenitic stainless steel in aging treatment was investigated by optical microscopy （OM）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results show that hexagonal intergranular and cellular Cr2N with a=0.478 nm and c=0.444 nm and body-centered cubic intermetaUic X phase with a=0.892 nm precipitate gradually in the isothermal aging treatment. The matrix nitrogen depletion due to the intergranular Cr2N precipitation induces the decay of Vickers hardness, and the formation of cellular Cr2N and X phase causes the increase in the values. The impact toughness presents a monotonic decrease and SEM morphologies show the leading brittle intergranular fracture. The tensile strength and elongation deteriorate obviously except for the sample aged for 1 h in yield strength. Stress concentration occurs when the matrix dislocations pile up at the pre- cipitation and matrix interfaces, and the interracial dislocations may become precursors to the misfit dislocations, which can form small cleavage steps and accelerate the formation of cracks.

关键词： microstructural evolution aging mechanical properties austenitic stainless steel secondary phase

Relationship between VEGF,EGF and Invasion,Metastasis of Gastric Cancer Cells

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Chinese Journal of Cancer Research 2009年第2期21卷 122-129页

作者： Chun-feng li Yan ma Yu-zhe Wei Ying-wei Xue Department of Abdominal Surgery Cancer Hospital Harbin Medical University Harbin 150081 China

Objective： To investigate the relationship between expression of vascular endothelial growth factor （VEGF）, epidermal growth factor （EGF） and the biological properties of gastric cancer cells such as invasion and metastasis. Methods： RT-PCR was performed to semi-quantitatively detect the mRNA expressions of EGF, EGFR, VEGF and VEGFR in four kinds of gastric cancer cell lines BGC823, MGCS03, HGC27 and SGC7901, which were classified by their differentiation degree in our experiment. We obtained cell line growth curves from MTT assays. The migration of gastric cancer cells was observed under inverted phase contrast microscope. The changes of invasion and adhesion were detected by a Transwell assay. Results： The growth rates slowed down sequentially in MGC803, HGC27, BGC823 and SGC7901（P〈 0.05）. The ability of migration, invasion and adhesion were reduced sequentially, and the difference was significant. The expressions of EGF, EGFR, VEGF and VEGFR were significantly stronger in MGCS03 and HGC27 than in BGC823 and SGC7901 cells, and the difference was statistically significant（P〈0.05）. Conclusion： The expressions of VEGF and EGF had close relationship with the properties of migration, adhesion and invasion of gastric cancer cells in vitro. Thus, targeting VEGF and EGF may be a potential therapeutic strategy for inhibiting peritoneal metastasis of gastric cancer.

关键词： Gastric cancer cells Vascular endothelial growth factor(VEGF) Epidermal growth factor(EGF),Metastasis

PEG-grafted PVA Membrane and Its Blood Compatibility

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Chemical Research in Chinese Universities 2011年第6期27卷 1078-1082页

作者： JIN Gu YAO Qi-zhi DONG li-quan ma feng Department of Chemistry University of Science and Technology of China Hefei 230026 P. R. China

Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.

关键词： Polyvinyl alcohol(PVA) Polyethylene glycol(PEG) Membrane Platelet Adhesion