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Effect of Microstructure on Corrosion Behavior of Mg–Sr Alloy in Hank's Solution

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Acta Metallurgica Sinica(English Letters) 2019年第3期32卷 305-320页

作者： Jia-hui dong Li-Li Tan Yi-Bin ren Ke Yang Institute of Metal Research Chinese Academy of Science School of Materials Science and Engineering University of Science and Technology of China

Mg–Sr alloy has been studied as a potential biodegradable material with excellent bioactivity to promote the bone formation. However, its degradation behavior needs to be well controlled to avoid the negative effect, which is important for future application. Therefore in this study, the microstructure and its effect on corrosion behavior of an Mg–1.5 Sr alloy were investigated. The microstructures of the alloy under different processing procedures were characterized by both optical and scanning electron microscopes. The corrosion performance was studied in Hank's solution using immersion,potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) tests. The results showed that the grain size and the amount and distribution of b-Mg_(17)Sr_2 had obvious effects on the corrosion behavior of Mg–Sr alloy. The smaller the grain size was, the more the protective surface layer formed on Mg–Sr alloy, and the higher the corrosion resistance was. For the as-cast Mg–Sr alloy, the network-like second phases precipitated along the grain boundaries could not hinder the corrosion due to their own corrosion cracking accelerating the intergranular corrosion. However, the refinement of second phases increased the corrosion resistance of the as-extruded alloy. After solution treatment at 450 °C for 5 h, the grains in the alloy did not grow much and b-Mg_(17)Sr_2 phases homogenously distributed in the alloy, resulting in the increase in corrosion resistance. However, after aging treatment, large amount of precipitated second phases increased the galvanic corrosion of the alloy, accelerating the development of corrosion.

关键词： Mg–Sr alloy Microstructure Corrosion Extrusion Heat treatment

Topological Aspects of Triplet Superconductors

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Communications in Theoretical Physics 2007年第5期47卷 944-948页

作者： ren Ji-Rong XU dong-hui ZHANG Xin-hui LI Ran Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

In this paper, using the Φ-mapping theory, it is shown that two kinds of topological defects, i.e., the vortex lines and the monopoles exist in the helical configuration of magnetic field in triplet superconductors. And the inner topological structure of these defects is studied. Because the knot solitons in the triplet superconductors are characterized by the Hopf invariant, we also establish a relationship between the Hopf invariant and the linking number of knots family, and reveal the inner topological structure of the Hopf invariant.

关键词： triplet superconductor topological defects Hopf invariant

The role of hyaluronic acid in biomineralization

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Frontiers of Materials Science 2012年第4期6卷 283-296页

作者： Zhen-Hua CHEN Xiu-Li ren hui-hui ZHOU Xu-dong LI 1College of Pharmacy Liaoning Medical UniversityJinzhou 121001China National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610064China Department of Chemicaland Biomolecular Engineering university of CaliforniaLos AngelesCA 90095USA

Hyaluronic acid has been extensively investigated due to intrinsic properties of natural origin and strong ability to bind ions in water. Hyaluronic acid is an excellent crystal modifier because its abundant negatively charged carboxyl groups can bind the cations protruding from the crystal lattice. In this review, we mainly present the latest work focus on the role of hyaluronic acid in controlling the crystallization, breaking the symmetry of crystal, and the surface funtionalization of nanocrystals.

关键词： hyaluronic acid biomineralization crystal growth extracellular matrix,bone and cartilage repair

Thinning intensity aff ects carbon sequestration and release in seasonal freeze–thaw areas

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Journal of Forestry Research 2023年第4期34卷 993-1006页

作者： Tong Gao Xinyu Song Yunze ren hui Liu Hangfeng Qu Xibin dong Key Laboratory of Sustainable Forest Management and Environmental Microorganism Engineering of Heilongjiang Province Northeast Forestry UniversityHarbin 150040People’s Republic of China

To explore how to respond to seasonal freeze–thaw cycles on forest ecosystems in the context of climate change through thinning,we assessed the potential impact of thinning intensity on carbon cycle *** varying the number of temperature cycles,the eff ects of various thinning intensities in four *** rate of mass,litter organic carbon,and soil organic carbon(SOC)loss in response to temperature variations was examined in two degrees of *** unfrozen season had the highest decomposition rate of litter,followed by the frozen ***-decomposed litter had a higher decomposition rate than undecomposed *** decomposition rate of litter was the highest when the thinning intensity was 10%,while the litter and SOC were *** litter had a good carbon sequestration impact in the unfrozen and freeze–thaw seasons,while the converse was confi rmed in the frozen and thaw *** best carbon sequestration impact was identifi ed in litter,and soil layers under a 20–25%thinning intensity,and the infl uence of undecomposed litter on SOC was more noticeable than that of semi-decomposed *** litter and soil can store carbon:however,carbon is transported from undecomposed litter to semi-decomposed litter and to the soil over *** summary,the best thinning intensity being 20–25%.

关键词： Forest carbon cycle Seasonal freeze–thaw Thinning Climate change

Application of dynamic vibration absorber for vertical vibration control of corrugated rolling mill

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Journal of Iron and Steel Research International 2023年第4期30卷 736-748页

作者： dong-ping He hui-dong Xu Ming Wang Tao Wang Chao-ran ren Zhi-hua Wang College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment Ministry of EducationTaiyuan 030024ShanxiChina

A variable mass tuned particle absorber is designed for the nonlinear vertical vibration control of the corrugated rolling mill in the composite plate rolling *** the nonlinear damping and nonlinear stiffness between the corrugated interface,a three-degree-of-freedom nonlinear vertical vibration mathematical model of corrugated rolling mill based on dynamic vibration absorber control is *** multi-scale method is used to solve the amplitude–frequency characteristic curve equation of the installed dynamic vibration absorber(DVA)*** effects of stiffness coefficient and damping coefficient on the amplitude–frequency characteristic curve are *** expressions of the dynamic developed factor of the corrugated roll are derived,and the influence laws of mass ratio,frequency ratio and damping ratio on the dynamic amplification factor are *** optimal parameters of the DVA are obtained by adaptive genetic *** control effect of the DVA on the nonlinear vertical vibration is studied by numerical *** feasibility of the designed dynamic absorber is verified through *** results show that the designed dynamic absorber can effectively suppress the vertical vibration of the corrugated roller.

关键词： Corrugated rolling mill Nonlinear vertical vibration Adaptive genetic algorithm Multiscale method Dynamic vibration absorber

Graphene： a promising 2D material for electrochemical energy storage

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Science Bulletin 2017年第10期62卷 724-740页

作者： Yanfeng dong Zhong-Shuai Wu Wencai ren hui-Ming Cheng Xinhe Bao Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences. Shenyang 110016 China Tsinghua-Berkeley Shenzhen Institute (TBSI) Tsinghua University Shenzhen 518055 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

Graphene, with unique two-dimensional form and numerous appealing properties, promises to remarkably increase the energy density and power density of electrochemical energy storage devices(EESDs),ranging from the popular lithium ion batteries and supercapacitors to next-generation high-energy batteries. Here, we review the recent advances of the state-of-the-art graphene-based materials for EESDs,including lithium ion batteries, supercapacitors, micro-supercapacitors, high-energy lithium-air and lithium-sulfur batteries, and discuss the importance of the pore, doping, assembly, hybridization and functionalization of different nano-architectures in improving electrochemical performance. The major roles of graphene are highlighted as(1) a superior active material,(2) ultrathin 2D flexible support,and(3) an inactive yet electrically conductive additive. Furthermore, we address the enormous potential of graphene for constructing new-concept emerging graphene-enabled EESDs with multiple functionalities of lightweight, ultra-flexibility, thinness, and novel cell configurations. Finally, future perspectives and challenges of graphene-based EESDs are briefly discussed.

关键词： Graphene Energy storageLithium ion batteries Supercapacitors Micro-supercapacitors Metal air batteries Lithium-sulfur batteries

Topological Aspects of Superconductors at Dual Point

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Communications in Theoretical Physics 2008年第6期49卷 1627-1630页

作者： ren Ji-Rong XU dong-hui ZHANG Xin-hui DUAN Yi-Shi Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

We study the properties of the Ginzburg-Landau model at the dual point for the superconductors. By making use of the U（1） gauge potential decomposition and the φ-mapping theory, we investigate the topological inner structure of the Bogomol＇nyi equations and deduce a modified decoupled Bogomol＇nyi equation with a nontrivial topological term, which is ignored in conventional model. We find that the nontrivial topological term is closely related to the N-vortex, which arises from the zero points of the complex scalar field, Furthermore, we establish a relationship between Ginzburg Landau free energy and the winding number.

关键词： dual point Bogomol'nyi equations vortex

Design and application of structural health monitoring system in long-span cable-membrane structure

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Earthquake Engineering and Engineering Vibration 2019年第2期18卷 461-474页

作者： Tang Teng Yang dong-hui Wang Lei Zhang Jian-ren Yi Ting-Hua School of Civil Engineering Changsha University of Technology Yueyang Sanhe Investment Management of Airport Construction Co.Ltd School of Civil Engineering Dalian University of Technology

Cable-membrane structures have small rigidity and are highly sensitive to wind. Structural health monitoring is necessary to ensure the serviceability and safety of the structure. In this research, the design method of a structural health monitoring system is using the characteristics of a cable-membrane structure. Taking the Yueyang Sanhe Airport Terminal as an example, a finite element model is established to determine the critical structural components. Next, the engineering requirements and the framework of the monitoring system are studied based on the results of numerical analysis. The specific implementation of the structural health monitoring is then carried out, which includes sensor selection, installation and wiring. The proposed framework is successfully applied to the monitoring system for the Yueyang Airport terminal building, and the synchronous acquisition of fiber Bragg grating and acceleration sensor signals is implemented in an innovative way. The successful implementation and operation of structural health monitoring will help to guarantee the safety of the cablemembrane structure during its service life.

关键词： cable-membrane structural health monitoring fi nite element model synchronous acquisition structural safety

A review of China's energy consumption structure and outlook based on a long-range energy alternatives modeling tool

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Petroleum Science 2017年第1期14卷 214-227页

作者： Kang-Yin dong ren-Jin Sun hui Li Hong-Dian Jiang School of Business Administration China University of Petroleum-Beijing Department of Agricultural Food and Resource EconomicsRutgers State University of New Jersey Energy Systems Research Center University of Texas at Arlington

China＇s energy consumption experienced rapid growth over the past three decades, raising great concerns for the future adjustment of China＇s energy consumption structure. This paper first presents the historical evidence on China＇s energy consumption by the fuel types and sectors. Then, by establishing a bottom-up accounting framework and using long-range energy alternatives plan- ning energy modeling tool, the future of China＇s energy consumption structure under three scenarios is forecast. According to the estimates, China＇s total energy con- sumption will increase from 3014 million tonnes oil equivalent （Mtoe） in 2015 to 4470 Mtoe in 2040 under the current policies scenario, 4040 Mtoe in 2040 under the moderate policies scenario and 3320 Mtoe in 2040 under the strong policies scenario, respectively, lower than those of the IEA＇s estimations. In addition, the clean fuels （gas, nuclear and renewables） could be an effective alternative to the conventional fossil fuels （coal and oil） and offer much more potential. Furthermore, the industry sector has much strong reduction potentials than the other sectors. Finally, this paper suggests that the Chinese government should incorporate consideration of adjustment of the energy consumption structure into existing energy policies and measures in the future.

关键词： Energy consumption structure China-LEAPmodel Scenario analysis Clean fuels Industrial sector