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Acta Metallurgica Sinica(English Letters) 2015年第5期28卷 649-655页

作者： Feng Li Wei Shi Nan Bian hong-bin wu School of Materials Science and Engineering Harbin University of Science and Technology

In order to study the influence of die combination on continuous variable cross-section direct extrusion （CVCDE） in the extrusion process, the accumulative strain formula is derived, and it can be known that the extrusion ratio of various stages directly determines the size of corresponding stage strain by formula. In this paper, as an example of the two interim dies, three die combinations of different angles and extrusion ratio are designed. Aviation magnesium alloy ZM6 is studied, and the results show that dynamic recrystallization is even more complete when continuous shear deformation occurs, so that the refinement and homogenization of microstructure are obtained. By the use of different die combinations, the accumulative strain increases under the conditions of same total extrusion ratio. Thus, the refined crystalline strengthening effect of extrusion deformation can be further analyzed. Due to the dead-zone defects, the actual accumulative strain decreases significantly and the effect of microstructure and performance improvements also decreases with it. Therefore, the optimal design of die combination is the key to the process and product of CVCDE, which provides a scientific basis for the development of severe plastic deformation.

关键词： Continuous variable cross-section direct extrusion (CVCDE) Die combination Accumulative strain Magnesium alloys Severe plastic deformation

Thermal stability of nanocrystalline layer prepared by surface mechanical attrition in 0Cr18Ni9Ti stainless steel

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中国有色金属学会会刊：英文版 2004年第z1期14卷 210-214页

作者： WANG hong-bin wu Xiao-chun XU Ling-yun School of Materials Science and Engineering Shanghai University Shanghai 200072 China School of Materials Science and Engineering Shanghai University Shanghai 200072 China School of Materials Science and Engineering Shanghai University Shanghai 200072 China

By means of surface mechanical attrition (SMA), a nanostructured surface layer was formed on a 0Cr18Ni9Ti austenite stainless steel plate. A strain-induced martensite transformation was observed during SMA treatment, and a single magnetic martensite phase layer with thickness of about 30 μm was gotten. The grain growth and phase transformations in the nanocrystalline layer are investigated during heating. The grain growth exponent for nanocrystalline polycrystalline steel is estimated. The kinetics mechanism governing the grain growth in the nanocrystalline layer is discussed. The martensite in the surface layer is quite stable and the temperature at which the reverse transformation of martensite to austenite starts during heating is about 500 ℃.

关键词： grain growth phase transformation surface mechanical attrition surface nanocrystalline layer

EFFICIENT WHITE EMITTING COPOLYMERS BASED ON BIPOLAR FLUORENE-co-DIBENZOTHIOPHENE-S,S-DIOXIDE-co-CARBAZOLE BACKBONE

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Chinese Journal of Polymer Science 2013年第1期31卷 88-97页

作者： Lei Ying Yan-hu Li Cai-hong Wei Min-quan Wang 杨伟 hong-bin wu Yong Cao State Key Laboratory of Luminescent Materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of Technology School of Material Science & Engineering South China University of Technology

Efficient white light emitting polymers were synthesized based on poly（9,9-dioctylfluorene-co-dibenzothiophene- S,S-dioxide） as blue emitter and a bisphenylamine functionalized 2,1,3-benzothiadiazole （DPABT） as red emitter. It was found that the incorporation of hole-transporting carbazole moiety into polymer main chain could effectively reduce the hole injection barriers, which can lead to distinctly improved charge balance in the emissive layer. Additionally, the hole- transporting carbazole units may form efficient bipolar host with electron-transporting dibenzothiophene-S,S-dioxide units. The white light emitting diodes based on single polymer PFSOCzDPABT showed the maximum luminous efficiency of 3.3 cd/A with the maximum luminance of 10282 cd/m2, and the luminous efficiency showed only 24% roll off at current density of 400 mA/cm2. These Commission Internationale d＇Enclairage （CIE） coordinates of the devices changed slightly with the driving voltages increasing from 8 V to 12 V, and were very close to National Television System Committee （NTSC） standard white light emission of （0.33, 0.33）. The results indicated that the incorporating bipolar host and low band gap DPABT unit was a promising way to achieve efficient single white light emitting copolymers.

关键词： Fluorene Dibenzothiophene-S,S-dioxide Carbazole White emitting polymer.

Modeling of the whole process of shock wave overpressure of freefield air explosion

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Defence Technology（防务技术） 2019年第5期15卷 815-820页

作者： Zai-qing Xue Shunping Li Chun-liang Xin Li-ping Shi hong-bin wu Beijing Institute of Space Long March Vehicle

The waveform of the explosion shock wave under free-field air explosion is an extremely complex *** is generally considered that the waveform consists of overpressure peak,positive pressure zone and negative pressure *** of current practice usually considers only the positive *** empirical relations are available to predict overpressure peak,the positive pressure action time and pressure decay ***,there are few models that can predict the whole *** whole process of explosion shock wave overpressure,which was expressed as the product of the three factor functions of peak,attenuation and oscillation,was proposed in the present *** to the principle of explosion similarity,the scaled parameters were introduced and the empirical formula was absorbed to form a mathematical model of shock wave *** numerical simulations of free-field air explosions were *** experimental verification of the AUTODYN numerical method and comparing the analytical and simulated curves,the model is proved to be accurate to calculate the shock wave overpressure under free-field air *** addition,through the model the shock wave overpressure at different time and distance can be displayed in three *** model makes the time needed for theoretical calculation much less than that for numerical simulation.

关键词： Air explosion Shock wave overpressure Free field Experimental verification Numerical simulation

Mars exploration——In situ K-Ar dating of jarosite

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Science China Earth Sciences 2024年第3期67卷 641-656页

作者： Jing YANG Dewen ZHENG Ying wu hong CHEN Li YANG bin ZHANG Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Institute of Earth Sciences China University of GeosciencesBeijing 100083China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029Chin

To accurately determine the chronological framework of climatic variations recorded by various Martian terrains, the absolute ages of Martian events and cratering rate need to be constrained by either in situ dating or returned samples. In situ K-Ar dating is currently a more plausible dating technique as compared with sample return. Jarosite(KFe_(3)[SO_(4)]_(2)[OH]_(6)) is the only confirmed K sulfate mineral that is widely present on Mars, as indicated by in situ detection, orbital remote sensing, and meteorite studies. Jarosite can be used for precise K-Ar and (40)Ar/(39)Ar dating. The preservation of jarosite on Mars provides information about the nature and duration of aqueous processes on the Martian surface. Different ages of Martian jarosite represent the key to constraining the transition from Martian surface water activity to arid climatic conditions. This paper summarizes recent advances in our knowledge of the spatial distribution of Martian jarosite, its mineralogical properties and stability on Mars, the Ar diffusion kinetics of jarosite, and the current status of in situ K-Ar dating. Moreover, we examine the key scientific issues to be addressed for in situ K-Ar dating of jarosite and Martian sample return missions, and discuss future research directions.

关键词： Mars Jarosite In situ K-Ar dating Ar diffusion Stability

Numerical Analysis of Effect of Water on Explosive Wave Propagation in Tunnels and Surrounding Rock

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Journal of China University of Mining and Technology 2007年第3期17卷 368-371页

作者： XIA Chang-jing SONG Zhen-duo TIAN Lu-lu LIU hong-bin WANG Lu wu Xiao-fang School of Mechanics ＆ Civil Engineering China University of Mining ＆ Technology Beijing 100083 China

Based on the application of practical engineering,propagation processes of explosive waves in rock with water well and tunnel are simulated by ANSYS/LS-DYNA software. The evolution of damage in rock is presented. The effect of water on the damage of the concrete slab in a tunnel is compared with damage inflicted without water. The numerical simulation illustrates that water plays an important role in the evolution of damage of the concrete slab in a mine tunnel. In the presence of water in the rock the concrete slab is damaged more severely than without water in rock. The effect of water location in the rock is also considered. It is found that the concrete slab in the tunnel shows various degrees of damage as a function of the different locations of water. Attenuation laws of stress waves over time-space in rock with water are also obtained. Numerical results indicate that,under blast loading,there are three zones in the rock: a crushed zone nearby the explosive charge,a damaged zone and an elastic zone. The conclusions of numerical analysis may provide references for blasting designs and structure protection.

关键词： explosive wave numerical simulation concrete slab damage evolution

Phase field modeling of grain stability of nanocrystalline alloys by explicitly incorporating mismatch strain

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Rare Metals 2024年第7期43卷 3370-3382页

作者： Min Zhou hong-Hui wu Yuan wu Hui Wang Xiong-Jun Liu Sui-He Jiang Xiao-bin Zhang Zhao-Ping Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083Cnina Institute for Carbon Neutrality University of Science and TechnologyBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China

Ab st ra ct Nanocrystalline materials exhibit unique properties due to their extremely high grain boundary(GB) ***,this high-density characteristic induces grain coarsening at elevated temperatures,thereby limiting the widespread application of nanocrystalline *** experimental observations revealed that GB segregation and second-phase pinning effectively hinder GB migration,thereby improving the stability of nanocry stalline *** this study,a mouified phase-field model that integrates mismatch strain,solute segregation and precipitation was developed to evaluate the influence of lattice misfit on the thermal stability of nanocrystalline *** simulation results indicated that introducing a suitable mismatch strain can effectively enhance the microstructural stability of nanocrystalline *** synergizing precipitation with an appropriate lattice misfit,the formation of second-phase particles in the bulk grains can be suppressed,thereby facilitating solute segregation/precipitation at the *** concentrated solute segregation and precipitation at the GBs effectively hinders grain migration,thereby preventing grain *** findings provide a new perspective on the design and regulation of nanocrystalline alloys with enhanced thermal stability.

关键词： Phase field model Mismatch strain Second-phase precipitation Grain boundary segregation Nanocrystalline alloys

Simultaneous acceleration of sulfur reduction and oxidation on bifunctional electrocatalytic electrodes for quasi-solid-state Zn–S batteries

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Science China Chemistry 2024年第5期67卷 1531-1538页

作者： Mingli Wang hong Zhang Tianhang Ding Fangjun wu Lin Fu bin Song Pengfei Cao Ke Lu Institutes of Physical Science and Information Technology School of Materials Science and EngineeringKey Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui UniversityHefei 230601China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China State Key Lab of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The incomplete sulfur reduction and high ZnS re-oxidation energy barrier along with severe side reactions during the battery cycling compromise the practical application of Zn–S electrochemistry. Herein, a bifunctional electrocatalytic sulfur matrix that simultaneously accelerates the sulfur reduction and ZnS oxidation is proposed to realize a highly-efficient Zn–S cell. It is revealed that the N-heteroatom hotspots are more favorable for facilitating the conversion of S to ZnS while the CoO nanocrystal substantially lowers the ZnS activation energy barrier thereby suppressing the formation of disproportionation species(e.g.,SO_(4)^(2-)) and accumulation of inactive ZnS. Accordingly, the Co O anchored on the N-doped carbon-supported sulfur cathode delivers a high Zn^(2+)storage capacity of 1,172 m Ahg^(-1)and outstanding cycling stability with a capacity retention of 71.6% after500 cycles with a high average Coulombic efficiency of 97.8%. Simultaneously, the stable cycling of solid-state Zn–S pouch cells with an energy density of 585 Whkg^(-1)sulfuris also demonstrated. Moreover, the postmortem analysis reveals that the degradation of Zn–S cells is mainly attributed to the limited reversibility of Zn anodes rather than the ZnS decomposition and/or accumulation. The approach to the bidirectional catalysis manipulated the sulfur redox provides a new perspective to realize the theoretical potentials of Zn–S cells.

关键词： Zn–S battery bifunctional catalysts solid-state battery sulfur redox degradation mechanism

Optical Microsphere Nano-Imaging:Progress and Challenges

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Engineering 2024年第5期36卷 102-123页

作者： Guangxing wu Minghui hong Department of Electrical and Computer Engineering National University of SingaporeSingapore 117576Singapore Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

The optical diffraction effect imposes a radical obstacle preventing conventional optical microscopes from achieving an imaging resolution beyond the Abbe diffraction limit and thereby restricting their usage in a multitude of nanoscale *** the past decade,the optical microsphere nanoimaging technique has been demonstrated to be a cost-effective solution for overcoming the diffraction limit and has achieved an imaging resolution of up to about k6k8 in a real-time and label-free manner,making it highly competitive among numerous super-resolution imaging *** this review,we summarize the underlying nano-imaging mechanisms of the microsphere nanoscope and key advancements aimed at imaging performance enhancement:first,to change the working environment or modify the peripheral hardware of a single microsphere nanoscope at the system level;second,to compose the microsphere compound lens;and third,to engineer the geometry or ingredients of *** also analyze challenges yet to be overcome in optical microsphere nano-imaging,followed by an outlook of this technique.

关键词： Microsphere Nano-imaging Virtual imaging Microsphere compound lens Engineered microsphere

OCTA characteristics in non-arteritic central retinal artery occlusion and correlation with visual acuity

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International Journal of Ophthalmology(English edition) 2024年第2期17卷 289-296页

作者： hong-Xia Gong bin wu Shi-Yong Xie Wei Zhang Song Chen Tianjin Key Lab of Ophthalmology and Visual Science Department of Ophthalmology for Integrated Traditional Chinese and Western MedicineTianjin Eye HospitalTianjin 300020China Clinical College of Ophthalmology Tianjin Medical UniversityTianjin 300010China Eye Hospital Affiliated to Nankai University Tianjin 300020China

AIM:To observe the retinal and choroidal circulations in patients with non-arteritic permanent central retinal artery occlusion(NA-CRAO)via optical coherence tomography angiography(OCTA)and analyze their correlation with visual ***:Sixty-two eyes with clinically confirmed acute NA-CRAO were included in the study and divided into:A type(mild n=29),B type(moderate n=27)and C type(severe n=6)based on the degree of visual loss,retinal edema,and arterial blood flow delay in fundus fluorescence angiography(FFA).Contralateral healthy eyes were used as the control ***-corrected visual acuity(BCVA),slit lamp microscopy,indirect ophthalmoscopy,fundus color photography,OCTA,and FFA were ***’s correlation analysis was used to determine the correlations between retinal and choroidal vessels and visual ***:There were no statistically significant differences in age,gender,and intraocular pressure among the three types and the control group(P>0.05).Vessel density in deep capillary plexus(VD-DCP)significantly decreased(P<0.05)in all three types of NA-CRAO patients compared to the control *** density in superficial vascular plexus(VD-SVP)significantly decreased(P<0.05)in type A patients and choriocapillaris flow area significantly decreased(P<0.05)in type B and type C patients compared to the control group;while outer retinal flow areas significantly increased in the type A(P<0.05)and decreased in type C patients(P<0.05).The retinal thickness significantly increased in type C group(P<0.05).The VD-SVP at fovea in the type A was significantly lower than both of type B and *** VD-SVP at nasal parafovea in type A and B was significantly lower than type C(P<0.05).The logMAR BCVA of type A was significantly better than that of type B and C groups(P<0.05).Spearman’s correlation analysis showed that the logMAR BCVA was positively correlated with VD-SVP at fovea(r=0.679,P=0.031)and nasal parafovea(r=0.826,P=0.013).CONCLUSION:OCTA is valua

关键词： non-arteritic central retinal artery occlusion fundus fluorescence angiography optical coherence tomography angiography retinal vessel density visual acuity