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Facile preparation of Nb_(2)O_(5) microspheres and their excellent electrochemical performance in aqueous zinc-ion hybrid supercapacitors

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Rare Metals 2022年第9期41卷 3129-3141页

作者： Si-Jia Zhang han Chen Yi-xue xu Chang-sheng An Kai-Xiong Xiang School of Materials and Advanced Manufacturing Liling Ceramic InstituteHunan University of TechnologyZhuzhou412007China Hunan Institute of Science and Technology Yueyang414000China Hunan Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha410022China

The aqueous solution-based zinc-ion hybrid supercapacitors(ZHSCs)have attracted immense attention as they are characterized by high power and energy densities.Electrode materials with high performance should be developed for ZHSCs to resolve power imbalances between capacitor-and battery-type electrode materials.To address this issue,Nb_(2)O_(5) microspheres(with the structure like sweet dumplings with exposed stuffing)were produced following a hydrothermal process which was followed by a high-temperature calcination process.The specific capacity of the as-synthesized Nb_(2)O_(5) microspheres was up to 324 F·g^(-1) when the current density was 0.1 A·g^(-1),and the long-term capacity retention was 85%at the end of 5000 cycles.The results revealed that the nanospheres could be used as battery-type electrode materials for the fabrication of ZHSCs.Nb_(2)O_(5)//AC ZHSCs were fabricated with Nb_(2)O_(5) microspheres as the negative electrode materials,and activated carbon(AC)was used as the positive electrode material.As a result,a specific capacity of 108 F·g^(-1) was achieved when the current density was 0.1 A·g^(-1).The power density was high(8020 W·kg^(-1))at 28 Wh·kg^(-1),and the energy density was high(60 Wh·kg^(-1))at 100 W·kg^(-1).The structurally novel Nb_(2)O_(5) microspheres can be potentially used for the development of the next-generation ZHSCs that exhibit excellent performance.

关键词： Hydrothermal Microspheres Nb_(2)O_(5) Zincion hybrid supercapacitors(ZHSCs) Fast kinetics

Breaking the von Neumann bottleneck:architecture-level processing-in-memory technology

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Science China(Information Sciences) 2021年第6期64卷 60-69页

作者： Xingqi ZOU sheng xu Xiaoming CHEN Liang YAN Yinhe han Institute of Computing Technology Chinese Academy of Sciences Zhejiang Lab Department of Computer Technology and Information Anhui Normal University University of Chinese Academy of Sciences

The "memory wall" problem or so-called von Neumann bottleneck limits the efficiency of conventional computer architectures, which move data from memory to CPU for computation; these architectures cannot meet the demands of the emerging memory-intensive applications. Processing-in-memory(PIM) has been proposed as a promising solution to break the von Neumann bottleneck by minimizing data movement between memory hierarchies. This study focuses on prior art of architecture level DRAM PIM technologies and their implementation. The key challenges and mainstream solutions of PIM are summarized and introduced. The relative limitations of PIM simulation are discussed, as well as four conventional PIM simulators.Finally, research directions and perspectives are proposed for future development.

关键词： processing-in-memory(PIM) von Neumann bottleneck memory wall PIM simulator architecture-level PIM

Elimination mechanism of coal and gas outburst based on geo‑dynamic system with stress–damage–seepage interactions

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International Journal of Coal Science & Technology 2023年第4期10卷 47-61页

作者： Lingjin xu Chaojun Fan Mingkun Luo sheng Li Jun han Xiang Fu Bin Xiao College of Mining Liaoning Technical UniversityFuxin 123000China Energy Business Department Shanxi Lu’an Chemical GroupChangzhi 046200China Resource Department Liaoning Geology Engineering Vocational CollegeDandong 118000China

Coal and gas outburst is a complex dynamic disaster during coal underground mining.Revealing the disaster mechanism is of great signifcance for accurate prediction and prevention of coal and gas outburst.The geo-dynamic system of coal and gas outburst is proposed.The framework of geo-dynamic system is composed of gassy coal mass,geological dynamic environment and mining disturbance.Equations of stress–damage–seepage interaction for gassy coal mass is constructed to resolve the outburst elimination process by gas extraction with boreholes through layer in foor roadway.The results show the occurrence of outburst is divided into the evolution process of gestation,formation,development and termination of geo-dynamic system.The scale range of outburst occurrence is determined,which provides a spatial basis for the prevention and control of outburst.The formation criterion and instability criterion of coal and gas outburst are established.The formation criterion F1 is defned as the scale of the geo-dynamic system,and the instability criterion F2 is defned as the scale of the outburst geo-body.According to the geo-dynamic system,the elimination mechanism of coal and gas outburst—‘unloading+depressurization’is established,and the gas extraction by boreholes through layer in foor roadway for outburst elimination is given.For the research case,when the gas extraction is 120 days,the gas pressure of the coal seam is reduced to below 0.4 MPa,and the outburst danger is eliminated efectively.

关键词： Coal and gas outburst Geo-dynamic system Stress–damage–seepage coupling Elimination mechanism Instability criterion Gas extraction

Marginal donor liver versus standard donor liver: A single-center observational study

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Hepatobiliary & Pancreatic Diseases International 2023年第3期22卷 239-244页

作者： Si-Long Gao Bao-Ying Mou De-Shu Dai Li han sheng-Bao Zhao Chuan-Shen xu Xiao xu Jin-Zhen Cai Intensive Care Unit the Affiliated Hospital of Qingdao UniversityQingdao 266000China Operating Room the Affiliated Hospital of Qingdao UniversityQingdao 266000China Organ Transplantation Center the Affiliated Hospital of Qingdao UniversityQingdao 266000China Department of Spinal surgery the Affiliated Hospital of Qingdao UniversityQingdao 266000China National Center for Healthcare Quality Management of Liver Transplant Hangzhou 310003China

Background:The effectiveness and safety of marginal donor livers remain controversial.This study aimed to investigate the clinical efficacy of marginal donor livers in patients with liver transplantation(LT).Methods:This study included 199 liver donors(including 16 split donors)and 206 liver recipients from January 1,2018 to January 27,2020,with case follow-up until July 31,2021.Clinical data of donors and recipients were retrospectively analyzed and were divided into the marginal donor and standard donor groups according to the criteria of marginal donor livers.Indices of liver and kidney functions,complications,and survival curves of the two groups were compared.Results:Compared with the standard donor group,the blood creatinine levels were significantly higher in the marginal donor group in the first week after operation(P0.05);there was no significant difference in the incidence of complications after LT(P>0.05);there was also no significant difference in the survival curve(P=0.335).Conclusions:There were no significant differences in liver and kidney function and survival curve between the standard donor and marginal donor groups.The marginal donor liver appears safe and reliable for LT and may be an important strategy to expand the donor pool and solve the shortage of organs.

关键词： Marginal donor Liver transplantation Liver function Organ donation

Effects of mild/asymptomatic COVID-19 on semen parameters and sex-related hormone levels in men:a systematic review and meta-analysis

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Asian Journal of Andrology 2023年第3期25卷 382-388页

作者： Bang-Wei Che Pan Chen Ying Yu Wei Li Tao Huang Wen-Jun Zhang Sheng-Han Xu Jun He Miao Liu Kai-Fa Tang Department of Urology The Affiliated Hospital of Guizhou Medical UniversityGuiyang 550004China

Coronavirus disease 2019(COVID-19)has yet to be proven to alter male reproductive function,particularly in the majority of mild/asymptomatic patients.The purpose of this study was to explore whether mild/asymptomatic COVID-19 affects semen quality and sex-related hormone levels.To find suitable comparative studies,a systematic review and meta-analysis was done up to January 22,2022,by using multiple databases(Web of Science,PubMed,and Embase).Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines were used to identify and choose the studies.Meta-analysis was used to examine the semen parameters and sex-related hormones of mild/asymptomatic COVID-19 patients before and after infection.The effects of semen collection time,fever,and intensity of verification on semen following infection were also investigated.A total of 13 studies(n=770)were included in the analysis,including three case-control studies,six pre-post studies,and four single-arm studies.A meta-analysis of five pre-post studies showed that after infection with COVID-19,sperm concentration(I^(2)=0;P=0.003),total sperm count(I^(2)=46.3%;P=0.043),progressive motility(I^(2)=50.0%;P<0.001),total sperm motility(I^(2)=76.1%;P=0.047),and normal sperm morphology(I^(2)=0;P=0.001)decreased.Simultaneously,a systematic review of 13 studies found a significant relationship between semen collection time after infection,inflammation severity,and semen parameter values,with fever having only bearing on semen concentration.Furthermore,there was no significant difference in sex-related hormone levels before and after infection in mild/asymptomatic patients.Mild/asymptomatic COVID-19 infection had a significant effect on semen quality in the short term.It is recommended to avoid initiating a pregnancy during this period of time.

关键词： coronavirus disease 2019 male infertility meta-analysis semen quality severe acute respiratory syndrome coronavirus 2

Deformation and fracture mechanisms of an annealing-tailored "bimodal" grain-structured Mg alloy

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Journal of Materials Science & Technology 2019年第11期35卷 2423-2429页

作者： Baojie Wang Daokui xu Liyuan sheng Enhou han Jie Sun School of Environmental and Chemical Engineering Shenyang Ligong UniversityShenyang110159China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Peking University Shenzhen InstituteShenzhen Key Lab Human Tissue Regenerate&RepairShenzhen518057China dEnvironmental Corrosion Center Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

Through investigating and comparing the mechanical behavior of an as-rolled Mg-3%Al-1%Zn(wt%)alloy before and after annealing treatments,it was revealed that the formation of annealing-tailored bimodal grain structure ensured the 330℃/4 h samples having a good combination of tensile strength and plasticity.Failure analysis demonstrated that for the as-rolled and 330℃/1 h samples with fine grain structure,their plastic deformation was mainly attributed to basal slips,whereas the deformation mechanism in the bimodal grain-structured samples was dominated by basal slips in fine grains and twinning in coarse grains.For the 330℃/8 h samples with coarse grain structure,high densities of twins were activated.Meanwhile,basal slips occurred in the twinned and un-twinned areas of coarse grains and could pass through twin boundaries.For differently treated samples,cracking preferentially occurred along slip bands,resulting in their transgranular fractures.

关键词： Mg alloy Grain structure Deformation mechanism Cracking Fracture

Numerical simulation of flow field characteristics and the improvement of pressure oscillation of rotating detonation engine

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Defence Technology（防务技术） 2023年第8期26卷 191-202页

作者： Xin-pei han Quan Zheng Bao-xing Li Qiang Xiao han xu Fang Wang Hao-long Meng Wen-kang Feng Chun-sheng Weng National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China Xi'an Modern Chemistry Research Institute Xi'an710065China

Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion performance.Therefore,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow field.The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy.In the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk structure.Moreover,the pressure monitoring points are set at the external flow field.The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened.Compared to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design.

关键词： Detonation flow field Combined chamber Pressure oscillation Velocity vector

3-Methylcyclohexanone Processed n-Channel Organic Thin-Film Transistors Based on a Conjugated Polymer Synthesized by Direct Arylation Polycondensation

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Chinese Journal of Polymer Science 2023年第5期41卷 824-831,I0012页

作者： Dong-sheng Yan xu-Wen Zhang Zhong-Li Wang Chen-Hui xu Yi-Bo Shi Yun-Feng Deng Yang han Yan-Hou Geng School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science Tianjin Universityand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin 300072China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Advanced Fibers and Energy StorageSchool of Material Science and EngineeringTiangong UniversityTianjin 300387China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was studied.The polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),etc.Based on the hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of PFuDPP-4FTVT.The morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation conditions.With a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by spin-coating.This is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.

关键词： Conjugated polymers Organic thin-film transistors Electron mobility Green solvent Direct arylation polycondensation

Effects of icosahedral phase on mechanical anisotropy of as-extruded Mg-14Li (in wt%) based alloys

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Journal of Materials Science & Technology 2019年第11期35卷 2477-2484页

作者： Chuanqiang Li Daokui xu Baojie Wang Liyuan sheng Ruizhi Wu Enhou han Peking University Shenzhen InstituteShenzhen Key Lab Human Tissue Regenerate&RepairShenzhen 518057China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China School of Environmental and Chemical Engineering Shenyang Ligong UniversityShenyang 110159China Key Laboratory of Superlight Materials&Surface Technology Ministry of EducationHarbin Engineering UniversityHarbin 150001China

Through investigating and comparing microstructure and crystallographic texture of as-extruded Mg-14Li and Mg-14Li-6Zn-1Y(in wt%)alloys,the differences in their mechanical anisotropy were investigated.It revealed that the formation of I-phase(Mg3Zn6Y,icosahedral structure)can effectively refine grain size.Moreover,compared with Mg-14Li alloy,the texture type of Mg-14Li-6Zn-1Y alloy changed slightly,but its texture intensity decreased remarkably.As a result,the stronger texture contributed to the"normal"mechanical anisotropy of Mg-14Li alloy with higher tensile strength and a lower elongation ratio along transverse direction(TD)than those along extrusion direction(ED).However,for Mg-14Li-6Zn-1Y alloy,the zonal distribution of I-phase particles along ED caused"abnormal"mechanical anisotropy,i.***.higher tensile strength and better plasticity along ED.

关键词： Mg-Li alloys Texture I-phase Mechanical anisotropy Fracture