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Research on theoretical and numerical methods of single bubble oscillation

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Journal of Hydrodynamics 2021年第4期33卷 872-877页

作者： Jie-min zhan Yue-han Chen Yu-tian Li Department of Applied Mechanics and Engineering Sun Yat-sen UniversityGuangzhou510275China

A comparison of theoretical investigation and numerical simulation of a single bubble oscillation is carried out in this *** theoretical research is based on solving Rayleigh-Plesset(R-P)equation and Keller-Miksis(K-M)equation using Runge-Kutta *** numerical method focuses on the two discrete methods in the volume of fluid(VOF)method,geometric reconstruction(GR)and modified high resolution interface capturing(MHRIC).The results show that the interface captured by MHRIC in the collapse stage is more stable,and the evolution of bubble radius agrees better with the theoretical *** R-P equation and K-M equation,which omit the effect of the energy equation,have limitations when the bubble collapses under ultra-high pressure.

关键词： Cavitation bubble dynamics volume of fluid method geometric reconstruction(GR)

Investigation on microstructure and internal friction for low density TiB_2/ZL114 composites

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Acta Metallurgica Sinica(English Letters) 2009年第3期22卷 211-218页

作者： Wenmao HUANG Haihong zhan Lingyan xu Zhengbing xu Jianmin ZENG Key Laboratory of Nonferrous Materials ＆ New Processing Technology Ministry of Education Guangxi University Nanning 530004 China

TiB2/ZL114 composites with the density of 2.733 g/cm^3 were fabricated through reaction of K2TiF4 and KBF4 （LSM method）. The composites were characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The internal friction measurements were performed on DTM-II-J dynamic modulus damping analyzer and the mechanisms were investigated. Experimental results indicate that reinforced particles are well-distributed in the matrix and the internal friction value of TiB2/ZL114 composites is up to a maximum of 9.04×10^-3, almost twice that of ZL114. The internal friction results form dislocation vibration within the material, the sliding of grain boundary and phase interface, and together with the micro-plastic deformation caused by difference in coefficients of thermal expansion and elasticity modulus of various phases. The average internal friction values of samples with the sizes of 40 mm×4 mm×2 mm, 40 mm×8 mm×2 mm and 40 mm×25 mm×2 mm are 8.83 ×10^-3, 8.89 × 10^-3, and 8.93× 10^-3, respectively. Thus, the developed composites are of low density, high internal friction, and the sizes of samples have no relation to the internal friction behavior.

关键词： LSM method TiB2/ZL114 composites Internal friction

Visualization of the protective role of estrogen against female liver fibrosis via an ER viscosity NIR fluorescent probe

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Science China Chemistry 2025年第1期68卷 360-368页

作者： Zheng Liu Changyu zhang Zipeng Li Wanying Ma Jia Liu Xiang Xia Ning xu Wen Sun Jianjun Du Jiangli Fan Xiaojun Peng State Key Laboratory of Fine Chemicals Dalian University of Technology Ningbo Institute of Dalian University of Technology

Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for investigations of HF *** twisted intramolecular charge transfer(TICT) and the excited state intramolecular proton transfer(ESIPT) are combined to endow HBT-PP with the selective response towards viscosity(～62-fold) and a super large stokes shift(～320 nm). HBT-PP mainly targets organelle ER and is able to image the drug-or alcohol-induced viscosity elevation in living cells. Significantly,HBT-PP was successfully applied to visualize the gender difference in HF and the protective role of estrogen in restraining HF progression. Of note, after 10 min of stain with HBT-PP, HF lesions showed a stage-based response, indicating the potential of this probe in fast and early diagnosis of HF. These results clearly demonstrated the promising application of HBT-PP as a new tool for exploring ER viscosity-involved physiological and pathological processes.

关键词： NIR fluorescent probe ER viscosity hepatic fibrosis gender difference estrogen

Preparation of Co/S co-doped carbon catalysts for excellent methylene blue degradation

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International Journal of minerals,Metallurgy and Materials 2025年第1期32卷 169-181页

作者： Haixu Li Haobo He Tiannan Jiang Yunfei Du Zhichen Wu Liang xu Xinjie Wang Xiaoguang Liu Wanhua Yu Wendong xue School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Beijing Jinyu Tongda Refractory Technologies Co. Ltd.Beijing 100085China

S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800℃at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate(PMS)for methylene blue(MB)*** effects of two different mixing routes were identified on the MB degradation ***,the catalyst obtained by the alcohol solvent evaporation(MOF-AEP)mixing route could degrade 95.60%MB(50 mg/L)within 4 min(degradation rate:K=0.78 min^(-1)),which was faster than that derived from the direct grinding method(MOF-DGP,80.97%,K=0.39 min^(-1)).X-ray photoelectron spectroscopy revealed that the Co-S content of MOF-AEP(43.39at%)was less than that of MOF-DGP(54.73at%),and the proportion of C-S-C in MOF-AEP(13.56at%)was higher than that of MOF-DGP(10.67at%).Density functional theory calculations revealed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton,which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond(-2.86 eV).Thus,the C-S-C sites might provide more contributions to activate PMS compared with ***,the degradation parameters,including pH and MOF-AEP dosage,were ***,radical quenching experiments and electron paramagnetic resonance(EPR)measurements revealed that ^(1)O_(2)might be the primary catalytic species,whereas·O~(2-)might be the secondary one in degrading MB.

关键词： advanced oxidation process alcohol solvent evaporation hydrogen bond S and Co co-doped carbon catalysts wastewater remediation

Singular Supercritical Trudinger-Moser Inequalities and the Existence of Extremals

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Acta Mathematica Sinica,English Series 2020年第8期36卷 873-888页

作者： xu min WANG School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China

In this paper,we present the singular supercritical Trudinger-Moser inequalities on the unit ball B in Rn,where n≥*** precisely,we show that for any given α>0 and 0 详细信息

In this paper,we present the singular supercritical Trudinger-Moser inequalities on the unit ball B in Rn,where n≥*** precisely,we show that for any given α>0 and 0

关键词： Singular supercritical Trudinger-Moser inequality radial lemma concentration-compactness principle extremal functions

Synthesis of new chiral 1,2,3,4-tetrahydroisoquinoline β-amino alcohols from L-DOPA

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Chinese Chemical Letters 2008年第11期19卷 1271-1273页

作者： Geng xu zhan Zhu Liu Institute of Materia Medica Peking Union Medical College ＆ Chinese Academy of Medical Science Beijing 100050 China

Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived β-amino alcohols were synthesized from L-DOPA in good yields. The structures of the target compounds were confirmed by ^1H NMR, ^13C NMR and MS.

关键词： β-Amino alcohol Tetrahydroisoquinoline L-DOPA Pictet-Spengler reaction

Analysis of solid-liquid-gas interactions in landfilled municipal solid waste by a bio-hydro-mechanical coupled model

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Science China(Technological Sciences) 2012年第1期55卷 81-89页

作者： CHEN Yunmin xu XiaoBing zhan LiangTong MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310058 China Tian Hua Architecture Planning Engineering Limited Shanghai 200233 China

Based on first-order kinetics of hydrolysis process, biodegradation of municipal solid waste （MSW） is assumed to obey a first-order decay equation which can take the direct effect of water content on biodegradation into account. Hydraulic model is an unsaturated-saturated flow model using mass conservation equations for fluids. Mechanical compression of MSW is ex- pressed by a stress-age coupled compression model. Through above models, a one-dimensional （I-D） bio-hydro-mechanical coupled model is established to analyze solid-liquid-gas interactions in landfilled MSW. Values of all the model parameters for current typical Chinese MSW are determined. Numerical analysis of a hypothetical waste sample in a closed system shows that gas pressure and gas concentration is extremely large which might cause severe gas explosion problem. Total gas production is about 267.0 m3 per wet ton of fresh wastes. For another hypothetical landfilled MSW layer, the coupled model predicts a dis- sipation of gas pressure during passive gas collection process. Annual gas production is large at the beginning of biodegradation, and then decreases with time. Surface settlement of the wastes increases quickly initially and then becomes stable with a compression strain of about 0.32 after 20 years.

关键词： municipal solid waste solid-liquid-gas interaction gas generation settlement

NUMERICAL SOLUTION OF THE NAVIER-STOKES EQUATIONS FOR 3-D REGION USING BODY-FITTED COORDINATE SYSTEM

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Journal of Hydrodynamics 1991年第3期3卷 105-109页

作者： Jie-min, zhan Di-ming, zhang Shongskan Univ Guangzhou China

A three-dimensional method is presented for the three dimensional Navier-Stokes equations using body-fitted coordinate system. For the convenience of generating the coordinate system, we give some slip-coordinate boundary conditions. Numerical results for driven flow in a polar cavity show excellent agreement with the experimental study given by L. Fuchs and N. Tillmark.

关键词： Computers Applications Fluid Mechanics Mathematical Models

Enantioselective addition of diethylzinc to aryl aldehydes catalyzed by 1,2,3,4-tetrahydroisoquinoline β-amino alcohol

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Chinese Chemical Letters 2010年第3期21卷 309-311页

作者： Geng xu[a] zhan Zhu Liu[a] [a] Key Laboratory of Bioactive Substances Resources Utilization of Chinese Herbal Medicine (Peking Union Medical College) Ministry of Education. Institute of Materia Medica Peking Union Medical College & Chinese Academy of Medical Sciences Beijing 100050 China

A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been *** 10 mol%of this chiral catalyst,secondary alcohols can be obtained in up to 87%yield a... 详细信息

关键词： β-Amino alcohol Tetrahydroisoquinoline Diethylzinc Asymmetric addition