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Design and fabrication of a low modulus β-type Ti-Nb-Zr alloy by controlling martensitic transformation

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Rare Metals 2018年第9期37卷 789-794页

作者： qing-Kun Meng Yu-Fei Huo Wen Ma Yan-Wei Sui Jin-Yong Zhang Shun Guo Xin-qing zhao School of Materials Science and Engineering China University of Mining and Technology GRINM Bohan (Beijing) Publisher Co. Ltd.GRINM Group Co.Ltd. School of Materials Science and Engineering Jiangsu University School of Materials Science and Engineering Beihang University

In this paper, high density of dislocations, grain boundaries and nanometer-scale α precipitates were intro- duced to a metastable Ti-36Nb-5Zr alloy （wt%） through a thermo-mechanical approach including severe cold rolling and short-time annealing treatment. The martensitic trans- formation was retarded, and the β phase with low content of β stabilizers was retained at room temperature after the thermo-mechanical treatment. As a result, both low mod- ulus （57 GPa） and high strength （950 MPa） are obtained. The results indicate that it is a feasible strategy to control martensitic transformation start temperature through microstructure optimization instead of composition design, with the aim of fabricating low modulus β-type Ti alloy.

关键词： Biomedical Ti alloys Martensitictransformation Low modulus Short-time annealing

Catalytic Conversion of CO2 to Cyclic Carbonates through Multifunctional Zinc-Modified ZSM-5 Zeolitet

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Chinese Journal of Chemistry 2018年第3期36卷 187-193页

作者： qing-Ning zhao qing-Wen Song Ping Liu Qian-Xia Zhang Jun-Hua Gao Kan Zhang State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan Shanxi 030001 China Department of Chemistry Shanghai University Shanghai 200444 China

The production of fine chemicals using CO2 as C1 building block through inexpensive heterogeneous catalysts with high efficiency under low pressure is challenging. Herein we propose for the first time the utilization of a multifunctional heterogeneous zinc-modified HZSM-5 （ZnHZSM-5） catalyst for upgrading CO2 by incorporation into cyclic carbonates from CO2 and epoxides. Owing to the nice surface properties such as abundant Lewis acid, Bronsted acid and Lewis base sites, large surface area, and plenty of micropores, CO2 could be concentrated and well activated in ZnHZSM-5 verified by CO2-TPD, TG-MS, etc. Meanwhile, the epoxides were also activated through metal center and hydrogen bond. Therefore, the reaction can easily assemble at the catalyst interface and show exceptional performance, affording the aimed products with high yield of up to 99% in the presence of commercial tetra-n-propylammonium bromide （90% in kilogram scale with 0.004 mol% ZnHZSM-S and 0.03.5 mol% n^Pr4NBr）.

关键词： carbon dioxide utilization zeolite heterogeneous catalysis multifunctional activation heterocycle

A Facile Photo-cross-linking Method for Polymer Gate Dielectrics and Their Applications in Fully Solution Processed Low Voltage Organic Field-effect Transistors on Plastic Substrate

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Chinese Journal of Polymer Science 2018年第8期36卷 918-924页

作者： Ying Liu Jia-qing zhao Wen-Jian Sun Yu-Kun Huang Su-Jie Chen Xiao-Jun Guo qing Zhang Shanghai Key Laboratory of Electrical Insulation and Thermal Aging Department of Polymer Science and EngineeringSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Department of Electronic Engineering School of Electronic Information and Electrical EngineeringShanghai Jiao Tong University

A simple and effective photochemical method was developed for cross-linking of polymer gate dielectrics. Laborious synthetic processes for functionalizing polymer dielectrics with photo-cross-linkable groups were avoided. The photo-cross-linker, BBP-4, was added into host polymers by simple solution blending process, which was capable of abstracting hydrogen atoms from polymers containing active C--H groups upon exposure to ultraviolet （UV） radiation. The cross-linking can be completed with a relatively long wavelength UV light （365 nm）. The approach has been applied to methacrylate and styrenic polymers such as commercial poly（methylmethacrylate）（PMMA）, poly（iso-butylmethacrylate）（PiBMA） and poly（4-methylstyrene）（PMS）. The cross-linked networks enhanced dielectric properties and solvent resistance of the thin films. The bottom-gate organic field-effect transistors （OFETs） through all solution processes on plastic substrate were fabricated. The OFET devices showed low voltage operation and steep subthreshold swing at relatively small gate dielectric capacitance.

关键词： Organic field-effect transistors Solution processed Polymer dielectric Cross-linking Photochemistry

Two-dimensional metallic CoTe_(2)flakes for electrocatalytic hydrogen evolution

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Rare Metals 2024年第11期43卷 5860-5867页

作者： Yu-qing zhao Qian Liu Bo-Jian Zhou Guang Yang Shao-Long Jiang School of Physics and Electronics Science Hunan University of Science and TechnologyXiangtan 411201China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210China Department of Physics Southern University of Science and TechnologyShenzhen 518055China School of Integrated Circuit Science and Engineering Beihang UniversityBeijing 100191China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

Two-dimensional(2D)metallic 1T-CoTe_(2)has attracted considerable attention due to its fascinating physical properties and promising applications in electronics and ***,the production of highquality 2D 1T-CoTe_(2)still remains ***,we demonstrate a methodology to realize the facile synthesis of ultrathin,high-quality CoTe_(2)flakes with a thickness down to 2.3 nm on mica substrates by an ambient-pressure chemical vapor deposition(CVD)*** atomic arrangement is verified by scanning transmission electron *** theoretical calculations uncover the metallic characteristic of 1T-CoTe_(2)in the 2D ***,the CVD-derived 2D metallic CoTe_(2)flakes for the hydrogen evolution reaction(HER)catalyst exhibit admirable performance,such as an overpotential of186 mV at 10 mA·cm^(-2),a Tafel slope of 78 mV·dec^(-1),an exchange current density of 69μA·cm^(-2),and negligible performance degradation after 1000 *** results establish novel approaches for the synthesis and HER application of 2D metallic 1T-CoTe_(2).

关键词： 2D metallic material 1T-CoTe_(2) Chemical vapor deposition Electrochemical hydrogen evolution

High-resolution neutronics model for ^(238)Pu production in high-flux reactors

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Nuclear Science and Techniques 2024年第5期35卷 226-236页

作者： qing-Quan Pan qing-Fei zhao Lian-Jie Wang Bang-Yang Xia Yun Cai Jin-Biao Xiong Xiao-Jing Liu School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610200China

We proposed and compared three methods(filter burnup,single energy burnup,and burnup extremum analysis)to build a high-resolution neutronics model for 238Pu production in high-flux *** filter burnup and single energy burnup methods have no theoretical approximation and can achieve a spectrum resolution of up to~1 eV,thereby constructing the importance curve and yield curve of the full energy *** burnup extreme analysis method combines the importance and yield curves to consider the influence of irradiation time on production efficiency,thereby constructing extreme *** three curves,which quantify the transmutation rate of the nuclei in each energy region,are of physical significance because they have similar distributions.A high-resolution neutronics model for ^(238)Pu production was established based on these three curves,and its universality and feasibility were *** neutronics model can guide the neutron spectrum optimization and improve the yield of ^(238)Pu by up to 18.81%.The neutronics model revealed the law of nuclei transmutation in all energy regions with high spectrum resolution,thus providing theoretical support for high-flux reactor design and irradiation production of ^(238)Pu.

关键词： ^(238)Pu Neutronics model High-flux reactor Spectrum resolution Spectrum optimization

Dispersion features of pollutants in a compound channel with vegetated floodplains

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Journal of Hydrodynamics 2022年第6期34卷 1095-1105页

作者： Yan-fang zhao Jing-jing Fan Wei-jie Wang Han-qing zhao Fei Dong Zhen Han Shi-yan Wang School of Water Conservancy and Hydroelectric Power Hebei University of EngineeringHandan056038China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing100038China China Three Gorges Corporation Wuhan430010China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Nanjing210024China

The planting of the vegetation on the floodplain helps the ecological restoration,which is the main form of the river’s ecological ***,the current research of the river dynamics focuses on the water movement under a compound channel with the vegetated *** simulated vegetation species are selected in this paper for the flume simulation experiments of the floodplain vegetation,and the compound channel is divided into three subregions in the transverse *** Navier-Stokes equation and the eddy viscosity theory are applied to obtain the transverse distribution of the depth-averaged velocity and the results agree well with the experimental *** paper proposes a new method based on the analytical solution of the flow velocity distribution to calculate the average flow velocity in each *** results can effectively simulate the average flow velocity of the measured *** description of the pollutant transport processes in a moving stream requires a refined determination of the dispersion coefficients in the compound *** process of the pollutant concentrations in each zone and the reasons for their occurrence are elucidated on the basis of the experimental ***,the measured values of the longitudinal dispersion coefficients are obtained by the“routing procedure,”and a two-zone model of the pollutant dispersion is constructed on the basis of the hydrodynamic *** prediction method for the longitudinal dispersion coefficients is also *** the predicted and measured section average flow velocities to the two-zone model to predict the longitudinal dispersion coefficient,and the average relative errors are only 4.17%,7.15%,*** result indicates that the two-zone model can effectively predict the longitudinal dispersion *** calculation methods for the longitudinal dispersion coefficients from—various studies are *** results reveal that the p

关键词： Compound channel floodplain vegetation velocity distribution pollutant transport dispersion coefficient

On Mechanisms of Proton Perpendicular Heating in the Solar Wind: Test Results Based on Wind Observations

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Research in Astronomy and Astrophysics 2022年第1期22卷 96-103页

作者： Guo-qing zhao Heng-Qiang Feng De-Jin Wu Qiang Liu Yan zhao Zhan-Jun Tian Institute of Space Physics Luoyang Normal UniversityLuoyang 471934China Henan Key Laboratory of Electromagnetic Transformation and Detection Luoyang 471934China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

The solar wind protons undergo significant perpendicular heating when they propagate in the interplanetary *** heating and cyclotron resonance heating due to kinetic Alfvén waves(KAWs) are two proposed mechanisms. Which mechanism accounts for the perpendicular heating is still an open question. This paper performs tests for the two mechanisms based on Wind observations during 2004 June and 2019 May. Results show that heating rates in terms of stochastic heating theory considerably depend on the parameter of plasma β. For the solar wind with moderately high β, the theoretical heating rates are comparable to or larger than empirical heating rates, suggesting that the stochastic heating could be a powerful mechanism. For the solar wind with low β, on the contrary, the majority of data have theoretical heating rates much lower than empirical heating rates, showing that the stochastic heating seems to be weak in this case. On the other hand, it is found that, when the propagation angles of KAWs are around 70°, theoretically predicted damping wavenumbers of KAWs are equal to the observed wavenumbers at which magnetic energy spectra become significantly steep. This may imply that resonance heating due to cyclotron damping of KAWs could be another mechanism if KAWs have propagation angles around 70°.

关键词： turbulence waves (Sun:)solar wind

Cryptochrome-mediated hypocotyl phototropism was regulated antagonistically by gibberellic acid and sucrose in Arabidopsis

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Journal of Integrative Plant Biology 2020年第5期62卷 614-630页

作者： qing-Ping zhao Jin-Dong Zhu Nan-Nan Li Xiao-Nan Wang Xiang zhao Xiao Zhang Key laboratory of Plant Stress Biology State Key Laboratory of Cotton BiologySchool of Life SciencesHenan UniversityKaifeng 475004China

Both phototropins(phot1 and phot2)and cryptochromes(cry1 and cry2)were proven as the Arabidopsis thaliana blue light *** predominately function in photomovement,and crypto-chromes play a role in *** cryptochromes have been proposed to serve as positive modulators of phototropic responses,the underlying mechanism remains ***,we report that depleting sucrose from the medium or adding gibberellic acids(GAs)can partially restore the defects in phototropic curvature of the phot1 phot2 double mutants under high-intensity blue light;this restoration does not occur in phott phot2 cry1 cry2 quadruple mutants and nph3(nonphototropic bypocotyl 3)mu-tants which were impaired phototropic response in sucrose-containing *** results indicate that GAS and sucrose antgonistically regulate hypocotyl phototropism in a cryptochromes dependent manner,butit showed a crosstalk with phototropin signaling on ***,cryptochromes activation by blue light inhibit GAS synthesis,thus stabilizing DELLAS to block hypocotyl growth,which result in the higher GAs content in the shade side than the lit side of hypocotyl to support the asymmetric growth of *** modulationof the abundance of DELLAS by sucrose depletion or added GAs,it revealed that cryptochromes have a function in mediating phototropic curvature.

关键词： Arabidopsis impaired curvature

Incipient motion of sediment in presence of submerged flexible vegetation

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Water Science and Engineering 2015年第1期8卷 63-67页

作者： Hao Wang Hong-wu Tang Han-qing zhao Xuan-yu zhao Sheng-qi Lü State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

The presence of submerged vegetation on river beds can change the water flow structure and alter the state of sediment motion. In this study, the incipient motion of sediment in the presence of submerged flexible vegetation in open channels was investigated in a laboratory experiment. The vegetation was simulated with flexible rubber cylinders arranged in parallel arrays. The effect of the vegetation density, water depth, and sediment grain size on the incipient motion was investigated. The experimental results indicate that the incipient motion velocity of sediment increases as the vegetation density decreases and the water depth and sediment grain size increase. With flexible plants, the incipient motion velocity of sediment is lower than it is without vegetation, and is larger than it is with rigid vegetation. A general incipient motion velocity equation was derived, which can be applied to both flexible and rigid vegetation conditions.

关键词： Sediment incipient motion Submerged flexible vegetation Open channel Experimentation Sediment grain size Water depth