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Copper Catalyzed Iodosulfenylation of Styrenes by Dual C--H Oxidative Functionalization

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Chinese Journal of Chemistry 2017年第3期35卷 307-310页

作者： Yurong Liu Bolun Hu xingguo zhang College of Chemisty and Materials Engineering Wenzhou University Wenzhou Zhejiang 325027 China

A new method for the synthesis of β ‐iodoalkenyl sulfides via copper catalyzed difunctionalization of styrenes is described. The method allows the formation of two chemical bonds, a C—I bond and a C—S bond, in a single reaction. Using alkenes in place of alkynes to synthesize β ‐iodoalkenyl sulfides is a significant advantage of this methodology for both synthetic and medicinal chemistry.

关键词： β‐iodoalkenyl sulfides iodosulfenylation iodine disulfides styrenes

Physical and numerical investigations of target stratum selection for ground hydraulic fracturing of multiple hard roofs

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International Journal of Mining Science and Technology 2024年第5期34卷 699-712页

作者： Binwei Xia Yanmin Zhou xingguo zhang Lei Zhou Zikun Ma State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China

Ground hydraulic fracturing plays a crucial role in controlling the far-field hard roof,making it imperative to identify the most suitable target stratum for effective *** experiments are conducted based on engineering properties to simulate the gradual collapse of the roof during longwall top coal caving(LTCC).A numerical model is established using the material point method(MPM)and the strain-softening damage constitutive model according to the structure of the physical *** simulations are conducted to analyze the LTCC process under different hard roofs for ground hydraulic *** results show that ground hydraulic fracturing releases the energy and stress of the target stratum,resulting in a substantial lag in the fracturing of the overburden before collapse occurs in the hydraulic fracturing *** hydraulic fracturing of a low hard roof reduces the lag effect of hydraulic fractures,dissipates the energy consumed by the fracture of the hard roof,and reduces the abutment ***,it is advisable to prioritize the selection of the lower hard roof as the target stratum.

关键词： Target stratum selection Ground hydraulic fracturing Hard roof control Fracture network Material point method

Microstructures and mechanical properties of AZ31-0.1Ca magnesium alloy produced by soft-contact electromagnetic casting and hot extrusion

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Acta Metallurgica Sinica(English Letters) 2010年第2期23卷 90-98页

作者： Zheng REN xingguo zhang Hai HAO Li SUI Tao zhang Yutao MA School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

An AZ31-0.1Ca magnesium alloy produced by Soft-contact electromagnetic continuous casting （SEMC） was investigated. The fine homogeneous structure and the precipitated phases were obtained by SEMC. The effects of microalloying of Ca and middle frequency electromagnetic field on AZ31-0.1Ca magnesium alloy were discussed. And the as-cast billets were extruded with different extrusion ratios subsequently. The alloy showed an ultrafine grain size of 2-5 #m due to dynamic recrytallization （DRX） in the course of hot extrusion. The comprehensive properties of the as-extruded alloy are the best at the extrusion ratio of 25, and the hardness, UTS and elongation are 73.9 HB, 356.8 MPa and 16.570, respectively.

关键词： SEMC Hot extrusion AZ31-0.1Ca Microstructure Mechanical properties

Effects of High Magnetic Field on Solidification and Corrosion Behaviors of Magnesium Alloy

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Journal of Materials Science & Technology 2007年第6期23卷 806-810页

作者： Canfeng FANG xingguo zhang Hai HAO Shouhua JI Junze JIN Department of Materials Processing Engineering School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

The solidification behaviors of AZ61 magnesium alloy under a high magnetic field were studied. The corrosion property of AZ61 alloy was investigated in a solution of 3.5 mol/L NaCI by measuring electrochemical ***. The results show that the high magnetic field can refine microstructure and benefit aluminum transfer. The crystal of α-Mg is induced to orient with their c-axis parallel to the magnetic field. The corrosion studies indicate that different crystal plane of magnesium has different corrosion property. The passivating films on the α- and b-planes have higher corrosion resistance than that on the c-plane. Aligned structure affects the corrosion property of AZ61 magnesium alloy.

关键词： Magnesium alloy High magnetic field Microstructure Corrosion

A Rubik’s microfluidic cube

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Microsystems & Nanoengineering 2020年第1期6卷 859-868页

作者： Xiaochen Lai Zhi Shi Zhihua Pu Penghao zhang xingguo zhang Haixia Yu Dachao Li State Key Laboratory of Precision Measurement Technology and Instruments Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments Tianjin UniversityTianjin 300072China

A Rubik’s cube as a reconfigurable microfluidic system is presented in this *** of physically interlocking microfluidic blocks,the microfluidic cube enables the on-site design and configuration of custom microfluidics by twisting the faces of the *** reconfiguration of the microfluidics could be done by solving an ordinary Rubik’s cube with the help of Rubik’s cube algorithms and computer *** O-ring-aided strategy is used to enable self-sealing and the automatic alignment of the microfluidic cube *** to the interlocking mechanics of cube blocks,the proposed microfluidic cube exhibits good reconfigurability and robustness in versatile applications and proves to be a promising candidate for the rapid deployment of microfluidic systems in resource-limited settings.

关键词： fluid enable sealing

Hot top electromagnetic casting research of Al thin slab

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中国有色金属学会会刊：英文版 1999年第3期9卷 605-610页

作者： zhang xingguo(张兴国) Tian Zhenghong(田正宏) Kang Junjie(康? ?) Jin Junze(金俊泽) Dalian Univ Technol Foundry Engn Res Ctr Dalian 116024 Peoples R China

The hot top EMC (electromagnetic casting) method was put forward, namely, the shape of top liquid column was formed by the hot top in the screen and the semi suspended liquid column was formed by the electromagnetic force nearby the liquid solid interface frontier. Using the numerical simulating technique, the temperature distribution was discussed, the effect of parameters such as upper conduct distance (UCD), cooling water rate of flow, pouring temperature and liquid column height on casting velocity were studied, the relationship among them was confirmed finally. According to the calculated results, the hot top EMC shaping system was designed and a lot of experiments were performed. The pure Al thin slabs of 480 mm×20 mm×850 mm were made successfully. The result showed that the casting velocity curve obtained experimentally almost coincides to the calculated one.

关键词： electromagnetic forming casting velocity thin slabs Document code: A

Modeling of mechanical properties of as-cast Mg-Li-Al alloys based on PSO-BP algorithm

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China Foundry 2012年第2期9卷 119-124页

作者： Li Ming Hao Hai zhang Aimin Song Yingde Liu Zhao zhang xingguo School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China

Artificial neural networks have been widely used to predict the mechanical properties of alloys in material research. This study aims to investigate the implicit relationship between the compositions and mechanical properties of as-cast Mg-Li-AI alloys. Based on the experimental collection of the tensile strength and the elongation of representative Mg-Li-AI alloys, a momentum back-propagation （BP） neural network with a single hidden layer was established. Particle swarm optimization （PSO） was applied to optimize the BP model. In the neural network, the input variables were the contents of Mg, Li and AI, and the output variables were the tensile strength and the elongation. The results show that the proposed PSO-BP model can describe the quantitative relationship between the Mg-Li-AI alloy＇s composition and its mechanical properties. It is possible that the mechanical properties to be predicted without experiment by inputting the alloy composition into the trained network model. The prediction of the influence of AI addition on the mechanical properties of as-cast Mg-Li-AI alloys is consistent with the related research results.

关键词： artificial neural networks Mg-Li-Al alloys BP algorithm particle swarm optimization mechanical properties

Effects of Spiral Magnetic Field on Structures Transformation and Macrosegregation of Sn-Pb Alloy

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Acta Metallurgica Sinica(English Letters) 2013年第3期26卷 345-351页

作者： xingguo zhang Qian ZHAO Jianshe GUO Qingyuan XING Liang DENG Xiaoguang HOU Canfeng FANG School of Materials Science and Engineering Dalian University of Technology Baoshan Iron and Steel Company Limited

The effect of spiral magnetic field （SMF） on the solidification process of Sn-20 wt.%Pb hypoeutectic alloy was studied in this work. The temperature distribution and the macrosegregation together with the eutectic lamellar spacing during solidification were measured under different magnetic fields. The results indicate that the compositions in the top and bottom portions of the sample are nearly the same and the segregation phenomenon is basically eliminated by SMF at an exciting current of 125 A. The morphology of the primary phase transforms from coarse dendrite to rosette or ellipsoidal equiaxed crystal and the spacing of the eutectic lamellar increases from 1.6 to 3.9 μm when the exciting current increases from 0 to 125 A. Moreover, if the exciting current is high enough, the forced fluid flow caused by SMF will enhance the process of transition from lamellar eutectic structure to anomalous rod-like one.

关键词： Spiral magnetic field Forced convection Eutectic lamellar spacing Sn-Pb alloy Composition segregation

Effects of Er on the microstructure and properties of AZ31 magnesium alloy prepared via the EMS process

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Rare Metals 2010年第4期29卷 339-345页

作者： MA Yutao,zhang xingguo,LIU Hongbin,and MENG Linggang School of Materials Science and Engineering,Dalian University of Technology,Dalian 116023,China School of Materials Science and Engineering Dalian University of Technology Dalian China

The effects of small amounts of the rare-earth element erbium on the microstructure and the mechanical properties of AZ31 magnesium alloy via the electromagnetic stirring （EMS） process have been studied. It has been shown that AZ31-Er alloys are mainly composed of α-Mg solid solution and β-Mg17TA112 phases. When the Er content reaches 0.12 wt.%, the characteristic peaks of A12Er can be observed. The micro- structure is obviously refined and the tensile strength of the AZ31-based alloy at ambient temperature is significantly improved by contents of 0.03 wt.% Er, especially the elongation （8= 19%）. More addition of Er obviously decreases the tensile strength and elongation of the AZ31-based alloy because of the grain coarsening and the reduction of β-Mg17A112 phases.

关键词： AZ31 magnesium alloy microstructure mechanical properties erbium