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Modeling and simulation of muzzle flow field of railgun with metal vapor and arc

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Defence Technology（防务技术） 2020年第4期16卷 802-810页

作者： yuan gao Yan-jie Ni zhao-xin Wang ying-tao Xu yong Jin Bao-ming li National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094JiangsuChina China Academy of Ordnance 100089BeijingChina

During the electromagnetic railgun launching process,there will be a complex flow field with high temperature in the muzzle area because of the high-speed friction,transition and seco ndary *** paper models the muzzle area of railgun when the projectile is far away from the muzzle,and the dynamic simulation of the flow field with secondary arc in the muzzle area is carried out based on the magneto hydrodynamic ***,a multi-component plasma transport model is used to analyze the muzzle arc plasma flow process of the mixed gas of Al vapor and the ***,the pressure boundary conditions are fitted by the dynamic mesh simulation *** current and voltage of the muzzle are obtained through the emission experiment of the railgun experimental *** load the current data into the simulation model and the voltage of experiments and simulations are compared,which proves the accuracy of the *** the plasma temperature and the composition of Al vapor in the muzzle flow process are analyzed in-depth.

关键词： Railgun Flow field Muzzle Plasma Simulation Al vapor

Synthesis and AO Resistant Properties of Novel Polyimide Fibers Containing Phenylphosphine Oxide Groups in Main Chain

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Chinese Journal of Polymer Science 2019年第1期37卷 59-67,1-3页

作者： yong zhao Hong gao Guo-Min li fang-fang liu Xue-Min Dai Zhi-Xin dong Xue-Peng Qiu Polymer Composites Engineering Laboratory Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences China Academy of Space Technology

A series of co-polyimide(PI)fibers containing phenylphosphine oxide(PPO)group were synthesized by incorporating the bis(4-aminophenoxy)phenyl phosphine oxide(DAPOPPO)monomer into the PI molecular chain followed by dry-jet wet *** effects of DAPOPPO molar content on the atomic oxygen(AO)resistance of the fibers were investigated *** the AO fluence increased from 0to 3.2×1020the mass loss of the fibers showed the dependence on DAPOPPO molar content in co-PI *** PI fiber containing 40%DAPOPPO showed lower mass loss compared to those containing 0%and 20%*** higher AO fluence,the higher DAPOPPO content gave rise to dense carpet-like surface of *** results indicated that the passivated phosphate layer was deposited on the fiber surface when exposed to AO,which effectively prevented fiber from AO *** the DAPOPPO content increasing from 0%to 40%,the retentions of tensile strength and initial modulus for the fibers exhibited obvious growth from 44%to 68%,and 59%to 70%,after AO exposure with the fluence of 3.2×1020The excellent AO resistance benefits the fibers for application in low Earth orbit as flexible construction components.

关键词： Polyimide fibers Bis(4-aminophenoxy)phenyl phosphine oxide(DAPOPPO) Dry-jet wet spinning AO resistance

Integrated simulation and monitoring to analyze failure mechanism of the anti-dip layered slope with soft and hard rock interbedding

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International Journal of Mining Science and Technology 2023年第9期33卷 1147-1164页

作者： Jinduo li yuan gao Tianhong yang Penghai Zhang yong zhao Wenxue Deng Honglei liu Feiyue liu Center for Rock Instability and Seismicity Research School of Resources&Civil EngineeringNortheastern UniversityShenyang 110819China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine Anhui University of Science&TechnologyHuainan 232001China

The significant difference between the mechanical properties of soft rock and hard rock results in the complexity of the failure mode of the anti-dip layered slope with soft and hard rock *** order to reveal the landslide mechanism,taking the north slope of Fushun West Open-pit Mine as an example,this paper analyzed the failure mechanism of different landslides with monitoring and field surveys,and simulated the evolution of *** study indicated that when the green mudstone(hard rock)of the anti-dip slope contains siltized intercalations(soft rock),the existence of weak layers not only aggravates the toppling deformation of anti-dip layered slope with high dip,but also causes the shear failure of anti-dip layered slope with stable low *** shear failure including subsidence induced sliding and wedge failure mainly exists in the unloading zone of the *** failure depth and failure time were far less than that of toppling *** terms of the development characteristics of deformation,toppling deformation has the long-term and progressive characteristics,but shear failure deformation has the abrupt and transient *** study has deepened the understanding of such slope landslide mechanism,and can provide reference for similar engineering.

关键词： Anti-dip layered slope Soft and hard rock interbedding Toppling failure Wedge failure Fushun West Open-pit Mine

Time-dependent borehole stability in hard-brittle shale

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Petroleum Science 2022年第2期19卷 663-677页

作者： Chuan-liang Yan Lei-Feng dong Kai zhao yuan-fang Cheng Xiao-Rong li Jin-Gen Deng Zhen-Qi li yong Chen Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina College of Petroleum Engineering Xi©an Shiyou UniversityXi©an710065ShaanxiChina State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China

Rock damage appears in brittle shale even prior to peak stress(i.e.,before failure)due to the occurrence of microcracks in these *** this work,a coupled hydromechanical model was built by incorporating the mechanical and fluid seepage induced stresses around a wellbore during *** borehole instability mechanism of hard-brittle shale was *** results show that even if a well is simply drilled into a hard-brittle shale formation,the formation around the borehole can be subjected to rock *** maximum failure ratio of the formation around the borehole increases with drilling time.A lower drilling fluid density corresponds to a faster increase in the failure ratio of the borehole with time and a shorter period of borehole *** the initial drilling fluid density is too low,serious rock damage occurs in the formation around the *** though a high-density drilling fluid is used after drilling,long-term borehole stability is difficult to *** drilling in hard-brittle shale,drilling fluid with a proper density should be used rather than increasing the density of the drilling fluid only after borehole collapse occurs,which is more favorable for maintaining long-term borehole stability.

关键词： Shale Rock damage Drilling fluid density Borehole stability

Phase jump in resonance harmonic emission driven by strong laser fields

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Chinese Physics B 2020年第2期29卷 243-248页

作者： yuan-yuan zhao Di zhao Chen-Wei Jiang Ai-Ping fang Shao-Yan gao Fu-li li School of Science Xi'an Jiaotong UniversityXi'an 710049China

We present a theoretical investigation of the multiphoton resonance dynamics in the high-order-harmonic generation(HHG)process driven by a strong driving continuous wave(CW)field along with a weak control harmonic *** Floquet theorem is employed to provide a nonperturbative and exact treatment of the interaction between a quantum system and the combined laser *** multiphoton-transition paths for the harmonic emission are coherently *** phase information about paths can be extracted via the Fourier transform analysis of the harmonic signals which oscillate as a function of the relative phase between driving and control *** jumps are observed when sweeping across the resonance by varying the frequency or intensity of the driving *** phase variation as a function of driving frequency at a fixed intensity and as a function of the intensity at a fixed driving frequency allows us to determine the intensity dependence of the transition energy of quantum systems.

关键词： phase jump high-order harmonic generation Stark-shifted transition energy

Modulating p-d orbital hybridization by CuO/Cu nanoparticles enables carbon nanofibers high cycling stability as anode for sodium storage

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Rare Metals 2023年第12期42卷 4039-4047页

作者： Zhi-Jia Zhang He-Yi Sun Yue-fang Chen Yu-Wen zhao Meng-Meng Zhang chun-Sheng li Yan Sun Zhong-Hui gao Hui-Jun li yong Jiang School of Materials Science and Engineering Institute of Quantum Materials and DevicesState Key Laboratory of Separation Membrane and Membrane ProcessesTiangong UniversityTianjin 300387China School of Chemistry and life Sciences School of Materials Science&Engineeringthe Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSuzhou University of Science and TechnologySuzhou 215009China School of Materials Science&Engineering The Key Laboratory of Advanced Ceramics and Machining Technology By the Ministry of Education of ChinaTianjin UniversityTianjin 300072China Faculty of Engineering and Information Sciences University of WollongongWollongongNSW 2522Australia

Carbon nanofibers(CNFs)have been extensively studied as anode materials for sodium-ion batteries due to their high conductivity,large aspect ratio and good electrochemical *** low specific capacity and low first cycle efficiency of CNFs,however,have hindered its practical ***,we present a facile strategy to synthesize a novel CNFs decorated with Cu/CuO nanoparticles(Cu-CNFs)using magnetron sputtering ***/CuO nanoparticles were uniformly distributed on the surface of *** to the density functional theory(DFT)calculation,Cu/CuO nanoparticles d-orbitals and CNFs p-orbitals present hybridization states,and the Na~+adsorption energy of the modified CNFs decreases from-2.14 to-2.97 *** Cu-CNFs composites exhibit excellent sodium storage properties,presenting a desirable initial Coulombic efficiency of 76%and a high specific reversible capacity of 300 mAh·g^(-1)at 0.1 A·g^(-1)after 400 ***-CNFs anode has excellent cycling stability under high current density,maintaining a high capacity of 150 mAh·g^(-1)at 1 A·g^(-1)after 6000 *** magnetron sputtering to regulate the electronic structure provides a new thought for improving the electrochemical performance of carbon materials.

关键词： Carbon nanofibers Cu/CuO nanoparticles Orbital hybridization Magnetron sputtering Density functional theory calculation

Bioinspired membranes for multi-phase liquid and molecule separation

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Science China Chemistry 2019年第1期62卷 14-23页

作者： Jingchong liu Zhimin Cui Lanlan Hou Dianming li yuan gao li Shuai Jing liu Jian Jin Nü Wang yong zhao Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and Devices School of Chemistry Beijing Advanced Innovation Center for Biomedical Engineering Beihang University i-Lab CAS Center for Excellence in Nanoscience and CAS Key Laboratory of Nano-Bio Interface Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences

Water pollution is a serious problem around the world. It causes the lack of clean drinking water and brings risks to human *** technology has become a competitive candidate to treat the contaminated wastewater due to its high separation efficiency and low energy consumption. In this review, we introduce the recent development of several kinds of bioinspired separation membranes, involving the membrane design and applications. We emphasize the multi-phase liquid separation membranes inspired from nature with special wettability applied for oil/water separation, organic liquids mixture separation, and emulsion separation. After separating multi-phase liquids using these membranes, small molecule pollutants still exist in singlephase liquid. Therefore, we also expand the scope to small molecule-scale separation membranes, such as the nacre-like graphene oxide separation membrane and other nanofiltration membranes. Summary and outlook concerning the future development of separation membranes are also introduced briefly.

关键词： bioinspired superhydrophobic superwettability nanofibers separation membrane

Realizing methanol synthesis from CO and water via the synergistic effect of Cu^(0)/Cu^(+)over Cu/ZrO_(2) catalyst

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Journal of Energy Chemistry 2024年第6期93卷 126-134,I0004页

作者： yuan fang Fan Wang yang Chen Qian Lv Kun Jiang Hua yang Huibo zhao Peng Wang Yuyan Gan lizhi Wu Yu Tang Xinhua gao li Tan Institute of Molecular Catalysis and In Situ/Operando Studies Fujian Key Laboratory of Electrochemical Energy Storage MaterialsState Key Laboratory of Photocatalysis on Energy and EnvironmentCollege of ChemistryFuzhou UniversityFuzhou 350108FujianChina Leibniz-Institut für Katalyse e.V.an der Universität Rostock Albert-Einstein Strasse 9118059 RostockGermany Department of Chemistry Tsinghua UniversityBeijing 100084China State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021Ningxi1China

The optimizing utilization of ca rbon resources has drawn wide attention all over the world,while exploiting the high-efficiency catalytic routes remains a ***,a direct methanol synthesis route is realized from pure CO and H_(2)O over 10%Cu/t-ZrO_(2) catalyst,where the time yield of methanol is144.43 mmol mol_(Cu)^(-1)h^(-1)and the methanol selectivity in hydrocarbons is 100%,The Cu species highly dispersed in the t-ZrO_(2) support lead parts of them in the cationic *** Cu^(+)sites contribute to the dissociation of H_(2)O,providing the H*source for methanol synthesis,while the formed Cu^(0) sites promote the absorption and transfer of H*during the ***,the H_(2)O is even a better H resource than H_(2) due to its better dissociation effectivity in this catalytic *** present work offers a new approach for methanol synthesis from CO and new insight into the process of supplying H donor.

关键词： H_(2)O CO Methanol Cu-based catalysts t-ZrO_(2)

Picosecond time-resolved X-ray ferromagnetic resonance measurements at Shanghai synchrotron radiation facility

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Nuclear Science and Techniques 2022年第5期33卷 126-134页

作者： Xia yang Jie-Feng Cao Jun-Qin li fang-yuan Zhu Rui Yu Jian He Zi-Long zhao yong Wang Ren-Zhong Tai Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

An experimental picosecond time-resolved X-ray ferromagnetic resonance(TR-XFMR)apparatus with a time resolution of 13 ps(RMS)or 31 ps(FWHM)was constructed and demonstrated in the 07U and 08U1A soft X-ray beamlines at the Shanghai Synchrotron Radiation Facility(SSRF)using pump-probe detection and X-ray magnetic circular dichroism(XMCD)*** and time-resolved ferromagnetic resonance was excited by continuous microwave phase-locking of the bunch clock within the photon beam during synchrotron radiation and was characterized by detecting the magnetic circular dichroism signals of the elements of interest in the magnetic *** this equipment,we measured the amplitude of the element-specific moment precession during ferromagnetic resonance(FMR)at 2 GHz in a single Ni81Fe19layer.

关键词： Ferromagnetic resonance Time resolution Pump-probe Synchrotron radiation