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Improvement in Time Efficiency in Numerical Simulation for solid Propellant Rocket Motors(SPRM)

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推进技术 2018年第1期39卷 92-99页

作者： Valeriy BUCHARSKYI ZHANG Li-hui WAN Yi-lun Propulsion System Design Dept Dnipro National University Dnipro 49000 Ukraine School of Astronautics Beihang University Beijing 100191 China

The main purpose of the present work is to study the possibilities of reducing calculation time while maintaining the validity in the numerical simulation of the combustion product flow in SPRM chamber.Three ways of decreasing the calculation time-the use of numerical methods of high accuracy order,the reduction in spatial dimension of the problem,and the use of physical features of the processes in SPRM chamber while constructing a calculation model-were considered.Presented calculation data show that the use of these approaches makes it possible to reduce the time for solving the problems of SPRM simulation significantly(up to 100times).Also conclusions about the applicability of the mentioned above approaches in SPRM design were made.

关键词： Numerical simulation solid propellant rocket motor Calculation time reduction

Effects of Plasticizers,Antioxidants and Burning Rate Modifiers on Aging Performance of the HTPB/HMDI Composite solid Propellant

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含能材料 2019年第1期27卷 21-27,90页

作者： Ahmed M Enew Ehab Abadir Sahar Elmarsafy Karim K Elsharkawy Chemical Department Faculty of EngineeringCairo University School of Chemistry and Environment Beijing University of Aeronautics and Astronautics

The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.

关键词： polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)composite solid propellant plasticizers antioxidants burning rate modifiers aging program

Borescopic particle image velocimetry in bubbling gas-solid fluidized beds

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Particuology 2019年第2期17卷 66-75页

作者： M. Banaei R. Dellaert N.G. Deen J.A.M. Kuipers M. van Sint Annaland Multiphase Reactors Group Department of Chemical Engineering & Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands Dutch Polymer Institute (DPI) P.O. Box 902 5600 AX Eindhoven The Netherlands Multiphase and Reactive Flows Group. Department of Mechanical Engineering Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands

In this work, the borescopic particle image velocimetry (BPIV) technique was applied to a bubbling gas-solid fluidized bed, and the results were compared with published positron emission particle tracking (PEPT) measurement data. Before performing the experiments, the sensitivity of the BPIV results to the illumination power, light reflectivity of the particles, and location of the borescope was also investigated. The BPIV and PEPT results were in fair agreement;however, some discrepancies were observed.The difference between the two sets of results were mainly caused by the intrusiveness of BPIV, the fact that the local solids volume fraction was not accounted for in the BPIV analysis, and the intrinsic differences of these two methods. Therefore, measurement of the local solids volume fraction with the borescope is highly recommended for further development of the BPIV method, which will also enable measureme nt of the local solids mass fluxes in side dense gas-solid fluidized beds.

关键词： Borescopic particle image velocimetry Gas-solid bubbling fluidized bed solid velocity profile Experimental investigation Hydrodynamics

Composite solid electrolyte of Na3PS4-PEO for all-solid-state SnS2/Na batteries with excellent interfacial compatibility between electrolyte and Na metal

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能源化学：英文版 2020年第2期29卷 73-78页

作者： Xiaoyan Xu Yuanyuan Li Jun Cheng Guangmei Hou Xiangkun Nie Qing Ai Linna Dai Jinkui Feng Lijie Ci SDU& Rice Joint Center for Carbon Nanomaterials Key Laboratory for Liquid-Solid Structural Evolution&Processing of Materials(Ministry of Education)School of Materials Science and EngineeringShandong UniversityJinan 250061ShandongChina

High ionic conductivity and superior interfacial stability of solid electrolytes at the electrodes are crucial factors for high-performance all-solid-state sodium batteries. Herein, a composite solid electrolyte Na3PS4-polyethylene oxide is synthesized by the solution-phase reaction method with an improved ionic conductivity up to 9.4 × 10-5 S/cm at room temperature. Moreover, polyethylene oxide polymer layer is wrapped homogeneously on the surface of Na3PS4 particles, which could effectively avoid the direct contact between Na3PS4 electrolyte and sodium metal, thus alleviate their side reactions. We demonstrate that all-solid-state battery SnS2/Na with the composite solid electrolyte Na3PS4-polyethylene oxide delivers an enhanced electrochemical performance with 230 m Ah/g after 40 cycles.

关键词： Composite solid electrolyte Na 3PS4 All-solid-state sodium battery SnS2

Improving the performance of solid oxide electrolysis cell with gold nanoparticles-modified LSM-YSZ anode

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Journal of Energy Chemistry 2019年第8期28卷 181-187,I0007页

作者： Yuefeng Song Xiaomin Zhang Yingjie Zhou Houfu Lv Qingxue Liu Weicheng Feng Guoxiong Wang Xinhe Bao State Key Laboratory of Catalysis CAS Center for Excellence in Nanoscience Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023 Liaoning China Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023 Liaoning China University of Chinese Academy of Sciences Beijing 100039 China

Gold, as the common current collector in solid oxide electrolysis cell(SOEC), is traditionally considered to be inert for oxygen evolution reaction at the anode of SOEC. Herein, gold nanoparticles were loaded onto conventional strontium doped lanthanum manganite-yttria stabilized zirconia(LSM-YSZ) anode, which evidently improved the performance of oxygen evolution reaction at 800 °C. The current densities at 1.2 V and 1.4 V increased by 60.0% and 46.9%, respectively, after loading gold nanoparticles onto the LSM-YSZ anode. Physicochemical characterizations and electrochemical measurements suggested that the improved SOEC performance was attributed to the accelerated electron transfer of elementary process in anodic polarization reaction and the newly generated triple phase boundaries in gold nanoparticles-loaded LSMYSZ anode.

关键词： solid oxide electrolysis cell Oxygen evolution reaction Gold nanoparticles CO2 electrolysis Strontium doped lanthanum manganite-yttria stabilized zirconia

Preparation and characterisation of solid dispersions of tanshinone ⅡA, cryptotanshinone and total tanshinones

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Asian Journal of Pharmaceutical Sciences 2017年第1期12卷 85-97页

作者： Xifeng Zhai Chunguang Li George Binh Lenon Charlie C.L.Xue Weize Li Traditional&Complementary Medicine Program School of Health SciencesRMIT UniversityBundooraVictoriaAustralia School of Pharmaceutical Sciences Xi’an Medical UniversityXi’anChina Center for Complementary Medicine Research National Institute of Complementary MedicineUniversity of Western SydneyCampbelltown CampusPenrithNew SouthWalesAustralia

Total tanshinones are lipophilic active constituents extracted from Salvia miltiorrhiza Bge.Tanshinone ⅡA and cryptotanshinone are the major components in total tanshinones.However, the bioavailability of both compounds is low due to poor water solubility. To enhance the solubility and dissolution rate of tanshinone ⅡA, cryptotanshinone and total tanshinones,three common used hydrophilic carriers including PEG 6000, poloxamer 188 and PVP K30 were used to prepare the solid dispersions at different ratios, respectively. The solid dispersions were characterised by scanning electron microscopy(SEM), differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR). The results of powder X-ray diffraction confirmed the microcrystal state of total tanshinones in solid dispersions and no chemical interaction between total tanshinones and carriers was observed in FTIR spectra. The solubility and dissolution rate of tanshinone ⅡA and cryptotanshinone were significantly increased in all solid dispersions. Regarding tanshinone ⅡA, the solubility and dissolution rate of in solid dispersions prepared with poloxamer 188 were significantly higher than that with PEG 6000 and PVP K30. The higher solubility and dissolution rate of cryptotanshinone were obtained in solid dispersion of PVP K30 than that of PEG 6000 solid dispersions but no significant difference from poloxamer 188 solid dispersions. The results indicate that the superior carrier for preparation of tanshinone ⅡA and total tanshinones solid dispersions is poloxamer 188, and that for cryptotanshinone is PVP K30.

关键词： Cryptotanshinone Tanshinone ⅡA Total tanshinones solid dispersion Dissolution rate

Strength criterion of composite solid propellants under dynamic loading

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Defence Technology（防务技术） 2018年第5期14卷 457-462页

作者： Zhe-jun Wang Hong-fu Qiang Guang Wang Biao Geng 206Staff Room Xi'an Hi-Tech Institute

Based on the dynamic loading(1-100 s^(-1)) experiments under different temperatures(223-298 K) and stress states, uniaxial and biaxial strength criterion of a Hydroxyl-terminated polybutadiene(HTPB)based composite solid propellant were further investigated. These experiments were conducted through the use of a new uniaxial INSTRON testing machine, different new designed gripping apparatus and samples with different configurations. According to the test results, dynamic uniaxial tensile strength criterion of the propellant was directly constructed with the master curve of the uniaxial maximum tensile stress. Whereas, a new method was proposed to determine the dynamic uniaxial compressive strength of the propellant in this study. Then uniaxial compressive strength criterion of the propellant was constructed based on the related master curve. Moreover, it found that the uniaxial tensilecompressive strength ratio of the propellant is more sensitive to loading temperature under the test conditions. The value of this parameter is about 0.4 at room temperature, and it reduces to 0.2-0.3 at low temperatures. Finally, the theoretical biaxial strength criterion of HTPB propellant under dynamic loading was constructed with the unified strength theory, the uniaxial strength and the typical biaxial tensile strength. In addition, the theoretical limit lines of the principal stress plane for the propellant under dynamic loading at different temperatures were further plotted, and the scope of the limit line increases with decreasing temperature.

关键词： Strength criterion Unified strength theory Composite solid propellant Dynamic loading Biaxial tension

Influence of fluoroethylene carbonate on the solid electrolyte interphase of silicon anode for Li-ion batteries:A scanning force spectroscopy study

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Chinese Physics B 2020年第4期29卷 58-66页

作者：郑杰允刘家亮王绥军罗飞贲留斌李泓 Beijing National Laboratory for Condensed Matter Physics.Institute of Physics.Chinese Academy of Sciences Beijing 100190China State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijing 100192China

Silicon is an important high capacity anode material for the next generation Li-ion batteries.The electrochemical performances of the Si anode are influenced strongly by the properties of the solid electrolyte interphase(SEI).It is well known that the addition of flouroethylene carbonate(FEC)in the carbonate electrolyte is helpful to improve the cyclic performance of the Si anode.The possible origin is suggested to relate to the modification of the SEI.However,detailed information is still absent.In this work,the structural and mechanical properties of the SEI on Si thin film anode in the ethylene-carbonate-based(EC-based)and FEC-based electrolytes at different discharging and charging states have been investigated using a scanning atomic force microscopy force spectroscopy(AFMFS)method.Single-layered,double-layered,and multi-layered SEI structures with various Young’s moduli have been visualized three dimensionally at nanoscale based on the hundreds of force curves in certain scanned area.The coverage of the SEI can be obtained quantitatively from the two-dimensional(2D)project plots.The related analysis indicates that more soft SEI layers are covered on the Si anode,and this could explain the benefits of the FEC additive.

关键词： Si fluoroethylene carbonate solid electrolyte interphase atomic force microscopy force spectroscopy

First‐mode of negative streamers:Inception at liquid/solid interfaces

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High Voltage 2021年第6期6卷 1069-1078页

作者： David Ariza Abderrahmane Beroual Ralf Methling Sergey Gortschakow Harold R.Chamorro School of Electrical Engineering KTH Royal Institute of TechnologyStockholmSweden Ecole Centrale de‐Lyon Ampère CNRS UMR 5005EcullyFrance Leibniz Institute for Plasma Science and Technology INP GreifswaldGermany

An experimental study of the inception of the first‐mode negative streamer at liquid/solid interfaces is presented in this article.The study is performed with a point‐plane configuration under square high voltage pulses.The electrode configuration is immersed in mineral oil and the liquid/solid interface is assembled in contact with the point electrode or in its vicinity.Four polymers and two impregnated papers have been tested as solids of the liquid/solid interface.Thus,it is possible to compare the influence of different parameter of the solid and the interface on the streamer inception.For example:Permittivity,solid surface roughness,chemical composition,etc.It has been observed that streamer inception voltages at interfaces with solids of higher permittivity to that of the mineral oil are statistically similar.Additionally,streamer inception voltages of streamer initiated free in the oil(no liquid/solid interface)are similar to that of the inception voltage of cases with solids with high permittivity.In contrast,the inception voltage of streamers initiated at permittivity matched interfaces are shown to be highest of the cases.The streamer inception voltage is also studied for different distances be-tween the liquid/solid interface and the point electrode with a permittivity matched interface.The results show a dependency of the inception voltage and the distance be-tween the point electrode and the interface.Finally,an analysis of the observation is performed to show that the Townsend‐Meek criterion cannot predict the obtained results.

关键词： solid liquid electrode