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SOLUTION CRYSTALLIZATION BEHAVIOR OF LINEAR AND STAR-SHAPED POLY(ETHYLENE GLYCOL)-b-POLY(ε-CAPROLACTONE) BLOCK COPOLYMERS

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Chinese Journal of Polymer Science 2013年第12期31卷 1717-1724页

作者： Ting Yu Jian-qiang Zhang Ya Lia Su-dan Shen Wen-feng Wei Peng Chen 王宗宝顾群 Ningbo Institute of material Technology and Engineering Chinese Academy of Sciences School of Petrochemical Technology Lanzhou University of Technology Institute of material Engineering Ningbo University of Technology

Lamellar crystals of diblock, triblock and four-arm poly（ethylene glycol）-b-poly（ε-caprolactone）（PEG-b-PCL） crystalline-crystalline copolymers were successfully obtained from their solution. Morphology and structure of lamellar crystals of crystalline-crystalline copotymers were investigated using tapping-mode atomic force microscopy （AFM） and selected area electron diffraction （SAED）. All of these samples showed the truncated-lozenge multilayer basal shapes with central screw dislocation or central stack, which were all obtained simultaneously from the oil bath. The diffraction pattern of PEG block lamellar crystal is attributed to the （120） diffracting planes and the pattern of PCL block lamellar crystal is attributed to the （1 I0） diffracting planes and （200） diffracting planes according to the SAED results. Four （110） crystal growth planes and two （200） crystal growth planes are discovered for the PCL blocks, but the （120） crystal growth planes of PEG blocks are hided in the figure of AFM. The crystalline structure of the four-arm copolymers （FA） is more disorder and confused than that of the diblock （DI） copolymer and the striated fold surface structures of lamellar crystals of four-arm copolymers （FA） are smoother than these of linear analogues, owing to the confused crystallization of blocks caused by the mutual restriction of blocks and the hindrance of the dendritic cores. In addition, the aspect ratio of FA is greater than that of the others. It is hypothesized that there are two reasons for the change of aspect ratios. First, the （200） diffracting planes of PCL crystals grew slowly compared to their （110） diffracting planes because of difference in the energy barrier. Secondly, edge dislocations on the （200） diffracting planes are also responsible for the variation of the aspect ratio. Consequently, the crystalline defects are augmented by the competing blocks crystallized simultaneously and the hindrance of the dendritic cores.

关键词： Lamellar crystal Topological structure PEG-b-PCL Edge dislocation Aspect ratio.

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Fracture sealing performance of granular lost circulation materials at elevated temperature:A theoretical and coupled CFD-DEM simulation study

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Petroleum Science 2024年第1期21卷 567-581页

作者： Chong Lin Qi-Cong Xu Lie-Xiang Han Gao Li Hai He Hong-Ling Zhou Ji-Ping She CCDC Drilling&Production Technology Research Institute Guanghan618300SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina College of materials Science and Engineering Chongqing UniversityChongqing400044China State Key Lab of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology) Chengdu610059SichuanChina College of energy Chengdu University of TechnologyChengdu610059SichuanChina

Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)*** circulation material(LCM)is a regular preventive and remedial measure for lost ***,conventional LCMs seem ineffective in high-temperature *** may be due to the changes in the mechanical properties of LCMs and their sealing performance under high-temperature *** understand how high temperature affects the fracture sealing performance of LCMs,we developed a coupled computational fluid dynamics-discrete element method(CFD-DEM)model to simulate the behavior of granular LCMs in *** summarized the literature on the effects of high temperature on the mechanical properties of LCMs and the rheological properties of drilling *** conducted sensitivity analyses to investigate how changing LCM slurry properties affected the fracture sealing efficiency at increasing *** results show that high temperature reduces the size,strength,and friction coefficient of LCMs as well as the drilling fluid ***,softer,and less frictional LCM particles have lower bridging probability and slower bridging *** particles tend to form dual-particle bridges rather than single-particle *** result in a deeper,tighter,but unstable sealing *** drilling fluid viscosity leads to faster and shallower sealing zones.

关键词： Geothermal well drilling HTHP formationLost circulation material CFD-DEM Fracture sealing

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Recent progress of two-dimensional metal-base catalysts in urea oxidation reaction

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Rare Metals 2024年第8期43卷 3607-3633页

作者： Qi-Xiang Huang Fang Wang Yong Liu Bi-Ying Zhang Fang-Ya Guo Zhong-Qiu Jia Hao Wang Tian-Xiang Yang Hai-Tao Wu Feng-Zhang Ren Ting-Feng Yi School of materials Science and Engineering Henan University of Science and TechnologyLuoyang 471000China School of Environmental Engineering and Chemistry Luoyang Institute of Science and TechnologyLuoyang 471023China Henan Province International Joint Laboratory of materials for Solar energy Conversion and Lithium Sodium Based Battery Luoyang 471023China School of Chemistry and Life Sciences Suzhou University of Science and TechnologySuzhou 215009China School of materials Science and Engineering Northeastern UniversityShenyang110819China

Urea oxidation reaction(UOR)is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption,which can produce hydrogen more efficiently by low theoretical potential,reduce the average cost of electrochemical hydrogen production,and is a frontier research hotspot for renewable hydrogen ***-dimensional(2D)nanomaterials as electrocatalysts have many favorable potential,such as it can effectively reduce the resistivity of materials and increase the specific surface area with *** paper reviews the application of 2D materials in UOR in alkaline *** a cross-sectional comparison of various material performance data including overpotential,Tafel slope,electrochemical active surface area(ECSA)and it stability test was conducted,which could illustrate the differences between materials composed of different *** addition,the main challenges hindering the progress of research on 2D materials in urea electrocatalysis processes and promising materials in this field in future are summarized and *** is believed that this review will contribute to designing and analyzing highperformance 2D urea electrocatalysts for water splitting.

关键词： Water splitting Urea oxidation reaction Two-dimensional Transition metal compounds Noble/non-noble metals

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Surface deterioration dependent on the crystal facets of spinel LiNi_(0.5)Mn_(1.5)O_(4) cathode active material

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Journal of energy Chemistry 2024年第10期97卷 757-766,I0016页

作者： Qian Li Yan Zhao Jifu Zhu Wujiu Zhang Yi Liu Yaru Cui Chao Shen Keyu Xie School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsNorthwestern Polytechnical University and Shaanx joint Laboratory of Graphene(NPU)Xi'an 710072ShaanxiChina Shaanxi Union Research Center of University and Enterprise for Cathode materials of LIBs Xi'an 710072ShaanxiChina CRRC Zhu Zhou Institute Co. Ltd.Zhuzhou 412000HunanChina

The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode active materials(CAMs)are considered a promising alternative to commercially available cathodes such as layered and polyanion oxide cathodes,primarily due to their notable safety and high energy density,particularly in their single-crystal ***,the industrial application of the LNMO CAMs is severely inhibited due to the interfacial deterioration and corrosion under proton-rich and high-voltage *** study successfully designed and synthesized two typical types of crystal facets-exposed single-crystal LNMO *** tracking the electrochemical deterioration and chemical corrosion evolution,this study elucidates the surface degradation mechanisms and intrinsic instability of the LNMO,contingent upon their crystal ***(111)facet,due to its elevated surface energy,is found to be more susceptible to external attack compared to the(100)and(110)*** study highlights the electrochemical corrosion stability of crystal plane engineering for spinel LNMO CAMs.

关键词： LiNi_(0.5)Mn_(1.5)O_(4) Crystal facets Electrochemical degradation Chemical corrosion Surface energy

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Emerging two-dimensional nanocatalysts for electrocatalytic hydrogen production

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Chinese Chemical Letters 2022年第4期33卷 1831-1840页

作者： Hong Chen Yansong Zhou Wei Guo Bao Yu Xia Key Laboratory of material Chemistry for energy Conversion and Storage(Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service FailureHubei Engineering Research Center for Biomaterials and Medical Protective MaterialsWuhan National Laboratory for OptoelectronicsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074China

Hydrogen energy could be a economic and powerful technology for sustainable future. Producing hydrogen fuel by electrochemical water splitting has attracted intense interest. Due to their physical and chemical properties, two-dimensional(2 D) nanomaterials have sparked immense interest in water electrocatalysis for hydrogen production. This review focuses on the emerging nanocatalysts in 2 D nanoarchitectures for electrocatalytic hydrogen production. The fundamentals of HER are firstly depicted, following the discussion of recent advances in typical 2 D electrocatalysts for HER. The insights into the relationship among the synthetic protocols, structure, catalytic performance and thermodynamics will be discussed in details. Finally, the outlooks regarding further development of 2 D nanocatalysts for HER are *** hope this review will offer a comprehensive understanding in 2 D nanocatalysts to promote electrochemical hydrogen production.

关键词： Hydrogen evolution Electrocatalyst Two-dimensional Active sites Modification

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Syntheses,structures,luminescent and magnetic properties of two coordination polymers based on a flexible multidentate carboxylate ligand

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Chinese Chemical Letters 2015年第5期26卷 499-503页

作者： Dan Tian Xiao-Jing Liu Rong-Ying Chen Ying-Hui Zhang Department of Chemistry and TKL of Metal-and Molecule-Based material Chemistry Key Laboratory of Advanced Energy Materials Chemistry(MOE)and Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai University

Two coordination polymers, {[Cu3（tci）2（DMAc）3].6DMAc-2H2O}n （1[） and {[Cu3（tci）2（tpt）2（H2O）2]- 2DMAc-2H2O}n （2）（H3tci = tris（2-carboxyethyl）isocyanurate, tpt = 2,4,6-tris（4-pyridyl）-l,3,5-triazine, DMAc = N,N-dimethylacetamide）, have been constructed under solvothermal conditions. Both polymers were structurally characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric （TG） analyses and powder X-ray diffraction （RXPD）. 1 shows a （3,4）-connected 2D layer structure comprising Cu2（CO2）4 paddle-wheel units, which are further bridged by C-H.--O interactions to give a 3D supramolecular network. The introduction oftpt produces different framework for 2 that comprises a dinuclear and a mononuclear Cu（II） building units, which are further bridged together by tci3- and tpt ligands to give a 4-connected 2D topological net. Adjacent 2D layers are packed together via C-H...O interactions and π...π stacking interactions to form a 3D supramolecular structure. In addition, the luminescent properties and the solid-state UV-vis spectra of I and 2 were explored. Furthermore, antiferromagnetic exchange interactions were unveiled in the Cu2（COO）4 units of 1. ~ 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

关键词： Coordination polymers X-ray crystallography Copper Magnetic properties Luminescence

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A water-stable metal-organic framework： serving as a chemical sensor of PO43– and a catalyst for CO2 conversion

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Science China Chemistry 2017年第10期60卷 1328-1333页

作者： Bin Zhai Hang Xu Zhong-Yi Li Chun-Shuai Cao Bin Zhao College of Chemistry and Chemical Engineering Shangqiu Normal University Shangqiu 476000 China Key Laboratory of Advanced energy material Chemistry Department of Chemistry Nankai University Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300071 China

A new 2D Eu-BTB framework(1) with stratified gridding structure of about 14.6×16.9was synthesized and *** 1 displays excellent water stability with the pH 2–12. The luminescent investigations suggest that 1 could represent a chemical sensor of PO43. with high sensitivity and selectivity. Importantly, 1 as a sensor of PO_4^(3-) can be reused at least five *** the other hand, the catalytic investigations of 1 were carried out, indicating that 1 could be demonstrated as a recyclable catalyst for CO_2 conversion with epoxides.

关键词： MOFs water and pH stability luminescent detection CO_2 conversion

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Experimental study of core MHD behavior and a novel algorithm for rational surface detection based on profile reflectometry in EAST

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Plasma Science and Technology 2024年第3期26卷 66-75页

作者：叶凯萱周振张涛马九阳王嵎民李恭顺耿康宁吴茗甫文斐黄佳张洋邵林明杨书琪钟富彬高善露喻琳周子强向皓明韩翔张寿彪李国强高翔 the EAST team Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People's Republic of China University of Science and Technology of China Hefei 230026People's Republic of China Hebei Key Laboratory of Compact Fusion Langfang 065001Peoples Republic of China ENN Science and Technology Development Co. Ltd.Langfang 065001Peoples Republic of China Advanced energy Research Center Shenzhen UniversityShenzhen 518060People's Republic of China

Microwave reflectometry is a powerful diagnostic that can measure the density profile and localized turbulence with high spatial and temporal resolution and will be used in ITER,so understanding the influence of plasma perturbations on the reflect signal is *** characteristics of the reflect signal from profile reflectometry,the time-of-flight(TOF)signal associated with the MHD instabilities,are investigated in *** a 1D full-wave simulation code by the Finite-DifferenceTime-Domain(FDTD)method,it is well validated that the local density flattening could induce the discontinuity of the simulated TOF signal and an obvious change of reflect *** TOF signals under different types of MHD instabilities(sawtooth,sawtooth precursors and tearing mode)are studied in detail and show agreement with the *** new improved algorithms for detecting and localizing the radial positions of the low-order rational surface,the cross-correlation and gradient threshold(CGT)method and the 2D convolutional neural network approach(CNN)are presented for the first *** is concluded that TOF signal analysis from profile reflectometry can provide a straightforward and localized measurement of the plasma perturbation from the edge to the core simultaneously and may be a complement or correction to the q-profile control,which will be beneficial for the advanced tokamak operation.

关键词： MHD instabilities profile reflectometry rational surface detection convolutional neural network(CNN) EAST tokamak

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Effect of Applied Pressure on the Joining of Combustion Synthesized Ni_3Al Intermetallics with Al Alloy

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Journal of materials Science & Technology 2008年第1期24卷 123-126页

作者： G.S.Cho J.H.Yang K.H.Choe K.W.Lee A.Ikenaga Advanced material Processing team Korea Institute of Industrial Technology 7-47 Songdo-Dong Yeonsu-Ku Incheon 406-840 Korea Department of Metallurgy and materials Science Graduate School of Engineering Osaka Prefecture University 1-1 Gakuen-Cho Sakai Osaka 599-8531 Japan

We focused on the surface reinforcement of ligth weight casting alloys with Ni-AI intermetallic compounds by in-situ combustion reaction to improve the surface properties of non-ferrous casting *** our previous works,green compact of elemental Ni and Al powders were reacted to form Ni-3Al intermetallic compound by SHS （Self-propagating high temperature synthesis） reaction with the heat of molten Al alloy and simultaneously bonded with Al casting *** some defects such as tiny cracks and porosities were remained in the reacted *** we applied pressure to prevent thermal cracks and fill up the pores with liquid Al alloy by squeeze casting *** compressed Al alloy bonded with the Ni-3Al intermetallic compound was sectioned and observed by optical microscopy and scanning electron microscopy （SEM）.The stoichiometric compositions of the intermetallics formed around the bonded interface and in the reacted compact were identified by energy dispersive spectroscopy （EDS） and electron probe micro analysis （EPMA）. Si rich layer was formed on the Al alloy side near the bonded interface by the sequential solidification of Al *** porosities observed in the reacted Ni-3Al compact were filled up with the liquid AI *** Si particles from the molten Al alloy were detected in the pores of reacted Ni-3Al intermetallic *** Al casting alloy and Ni-3Al intermetallic compound were joined very soundly by applying pressure to the liquid Al alloy.

关键词： Joining Combustion synthesis Ni3AI Intermetallic compound Squeeze casting

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Heat-treated glassy carbon under pressure exhibiting superior hardness,strength and elasticity

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Journal of Materiomics 2021年第1期7卷 177-184页

作者： Meng Hu Shuangshuang Zhang Bing Liu Yingju Wu Kun Luo Zihe Li Mengdong Ma Dongli Yu Lingyu Liu Yufei Gao Zhisheng Zhao Yoshio Kono Ligang Bai Guoyin Shen Wentao Hu Yang Zhang Ralf Riedel Bo Xu Julong He Yongjun Tian Center for High Pressure Science(CHiPS) State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao066004China Fachbereich material-und Geowissenschaften Technische Universitat DarmstadtOtto-Berndt-Str.3Darmstadt64287Germany Key Laboratory for Microstructural material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao066004China High Pressure Collaborative Access team(HPCAT) Advanced Photon SourceArgonne National LaboratoryIL60639USA Institute of High energy Physics Chinese Academy of ScienceBeijing100049China

Glassy carbon(GC)is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures,which has been widely used due to its excellent mechanical *** we report the changes in the microstructure and mechanical properties of GC treated at high pressures(up to 5 GPa)and high *** formation of intermediate sp2-sp3 phases is identified at moderate treatment temperatures before the complete graphitization of GC,by analyzing synchrotron X-ray diffraction,Raman spectra,and transmission electron microscopy *** intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa,nearly doubling those of raw GC,and improving elasticity and thermal *** synthesis pressure used in this study can be achieved in the industry on a commercial scale,enabling the scalable synthesis of this type of strong,hard,and elastic carbon materials.

关键词： Glassy carbon Industrially achievable pressure sp2-sp3 intermediate carbon Hardness Strength Elasticity

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