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11篇 您的检索式:作者名="Defeng Yan"
    题名 作者 年代 出处 被引量
1Effect of puerarin on myocardial perfusion and ventricular wall motion in patients with acute coronary syndrome显示文摘Objective To investigate the effects of puerarin (Pur) on myocardial perfusion and ventricular wall motion in patients with acute coronary syndrome (ACS).Methods Thirty-seven patients with ACS were randomly divided into two groups:conventional treatment group (n= 17,11 males,range of age:32-80 years,average age:60.9±4.9 years) and Pur treatment group (n=20,12 males,range of age:40-76 years,average age:62.7±3.5 years).Patients in the conventional treatment group received standard treatment according to the current guidelines,while patients in the Pur treatment group received intravenous administration of Pur (500 mg/day) for 10 days plus conventional treatment.Real-time myocardial contrast echocardiography (RT-MCE) was performed to evaluate the change in myocardial perfusion index (MPI) and ventricular wall motion index (VWMI) at admission and 10 days after treatment.Results At 10 days after treatment,MPI was significantly higher (P<0.01) and VWMI significantly lower (P<0.01) in the Pur group comparing with those in the conventional group.Conclusions Puerarin might improve myocardial microcirculation perfusion and ventricular wall motion in patients with ACS.Ling Niu Dongye Li Yong Xia Defeng Pan Xiaoping Wang Yan Yan Li Liang Tongda Xu Cardiovascular Institute of Xuzhou Medical College, Department of Cardiology, Affiliated Hospital, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China 2008Journal of Geriatric Cardiology2008,5,3:3
2Finite element modelling on microstructure evolution during multi-pass hot compression for AZ31 alloys using incremental method显示文摘Based on the principle of piecewise linearization, the incremental forms of microstructure evolution models were integrated into the thermo-mechanical coupled finite element(FE) model to simulate nonlinear microstructure evolution during multi-pass hot deformation. This is an unsteady-state deformation where dynamic recrystallization(DRX), meta-dynamic recrystallization(MDRX), static recrystallization(SRX) and grain growth(GG) take place during hot deformation or deformation interval. The distributions of deformation and microstructure for cylindrical AZ31 sample during single-pass and double-pass hot compressions were quantitatively calculated and compared with the metallographic observation. It is shown that both the deformation and microstructure are non-uniformly distributed due to the presence of friction between the die and the flat end of sample. The average grain size and its standard deviation under the double-pass hot compression are slightly smaller than those under single-pass compression.The simulated average grain sizes agree well with the experiments, which validates that the developed FE model on the basis of incremental forms of microstructure evolution models is reasonable.Zhaoyang Jin Kai Yin Kai Yan Defeng Wu Juan Liu Zhenshan Cui 2017Journal of Materials Science & Technology2017,33,11:3
3An NF-[kappa]B pathway-mediated positive feedback loop amplifies Ras activity to pathological levels in mice显示文摘Daniluk Jaroslaw Liu Yan Deng Defeng Chu Jun Huang Haojie Gaiser Sebastian Cruz-Monserrate Zobeida Wang Huamin Ji Baoan Logsdon Craig D 2012EN2012,,4:1
4A Fluorescent Chemosensor for Al3+ Based on C=O Isomerization Derivated from Curcumin显示文摘Zhengyi Li Jinbei Yan Yue Yin Zhihui Zhang Zhiming Wang Defeng Xu Xiaoqiang Sun 2016Chinese Journal of Chemistry2016,34,7:1
5High-energy-density plasma in femtosecond-laser-irradiated nanowire-array targets for nuclear reactions显示文摘In this work,the high-energy-density plasmas(HEDP)evolved from joule-class-femtosecond-laser-irradiated nanowire-array(NWA)targets were numerically and experimentally studied.The results of particle-in-cell simulations indicate that ions accelerated in the sheath field around the surfaces of the nanowires are eventually confined in a plasma,contributing most to the high energy densities.The protons emitted from the front surfaces of the NWA targets provide rich information about the interactions that occur.We give the electron and ion energy densities for broad target parameter ranges.The ion energy densities from NWA targets were found to be an order of magnitude higher than those from planar targets,and the volume of the HEDP was several-fold greater.At optimal target parameters,8%of the laser energy can be converted to confined protons,and this results in ion energy densities at the GJ/cm^(3) level.In the experiments,the measured energy of the emitted protons reached 4 MeV,and the changes in energy with the NWA’s parameters were found to fit the simulation results well.Experimental measurements of neutrons from 2H(d,n)3He fusion with a yield of(24±18)×10^(6)/J from deuterated polyethylene NWA targets also confirmed these results.Defeng Kong Guoqiang Zhang Yinren Shou Shirui Xu Zhusong Mei Zhengxuan Cao Zhuo Pan Pengjie Wang Guijun Qi Yao Lou Zhiguo Ma Haoyang Lan Wenzhao Wang Yunhui Li Peter Rubovic Martin Veselsky Aldo Bonasera Jiarui Zhao Yixing Geng Yanying Zhao Changbo Fu Wen Luo Yugang Ma Xueqing Yan Wenjun Ma 2022Matter and Radiation at Extremes2022,7,6:1
6Copper catalyzed borylative cyclization of 3-arylallyl carbamoyl chloride with B_(2)pin_(2):stereoselective synthesis of cis-2-aryl-3-boryl-γ-lactams显示文摘Borylative cyclization of E-3-arylallyl carbamoyl chlorides is achieved through copper catalyzed intramolecular carboboration with B_(2)pin_(2).2-Aryl-3-boryl-γ-lactams are formed with exclusive cisdiastereoselectivity.CuBr-Dppp combination gives the best outcomes.The substrate scope is profiled.Mei-Hua Shen Ting-Biao Wan Xiu-Rong Huang Yan Li Dan-Hua Qian Hua-Dong Xu Defeng Xu 2021Chinese Chemical Letters2021,32,7:0
7Synchronous post-acceleration of laser-driven protons in helical coil targets by controlling the current dispersion显示文摘Post-acceleration of protons in helical coil targets driven by intense,ultrashort laser pulses can enhance ion energy by utilizing the transient current from the targets’self-discharge.The acceleration length of protons can exceed a few millimeters,and the acceleration gradient is of the order of GeV/m.How to ensure the synchronization between the accelerating electric field and the protons is a crucial problem for efficient post-acceleration.In this paper,we study how the electric field mismatch induced by current dispersion affects the synchronous acceleration of protons.We propose a scheme using a two-stage helical coil to control the current dispersion.With optimized parameters,the energy gain of protons is increased by four times.Proton energy is expected to reach 45 MeV using a hundreds-of-terawatts laser,or more than 100 MeV using a petawatt laser,by controlling the current dispersion.Zhipeng Liu Zhusong Mei Defeng Kong Zhuo Pan Shirui Xu Ying Gao Yinren Shou Pengjie Wang Zhengxuan Cao Yulan Liang Ziyang Peng Jiarui Zhao Shiyou Chen Tan Song Xun Chen Tianqi Xu Xueqing Yan Wenjun Ma 2023High Power Laser Science and Engineering2023,11,4:0
8Effect of particle gradation on pore structure and seepage law of solution in weathered crust elution-deposited rare earth ores显示文摘Both CT and Avizo software were used to explore the effect of particle gradation on the evolution characteristics of pore structure and seepage paths in weathered crust elution-deposited rare earth ores during leaching.The results showed that the pore areas in four kinds of ore samples before leaching were mainly concentrated in 10^(4)–10^(7)μm^(2),whose pore quantities accounted for 96.89%,94.94%,90.48%,and 89.45%,respectively,while the corresponding pore volume only accounted for 30.74%,14.55%,7.58%,and 2.84%of the total pore volume.With the decrease of fractal dimension,the average pore throat length increased,but pore throat quantities,the average pore throat radius and coordination number decreased.Compared with that before leaching,the change degree of pore structure during leaching increased with the fractal dimension decreasing.For example,the reduction rate of the average coordination number of ore samples was 14.36%,21.30%,28.00%,and 32.90%,respectively.Seepage simulation results indicated that seepage paths were uniformly distributed before leaching while the streamline density and seepage velocity increased with the fractal dimension decreasing.Besides,the phenomenon of the streamline interruption gradually reduced during leaching while preferential seepage got more obvious with the decrease of the fractal dimension.Defeng Liu Wenxin Yan Zhenyue Zhang Ruan Chi 2023International Journal of Mining Science and Technology2023,33,10:0
9Facile and Economical Fabrication of Superhydrophobic Flexible Resistive Strain Sensors for Human Motion Detection显示文摘Superhydrophobic flexible strain sensors have great application value in the fields of personal health monitoring,human motion detection,and soft robotics due to their good flexibility and high sensitivity.However,complicated preparation processes and costly processing procedures have limited their development.To overcome these limitations,in this work we develop a facile and low-cost method for fabricating superhydrophobic flexible strain sensor via spraying carbon black(CB)nanoparticles dispersed in a thermoplastic elastomer(SEBS)solution on a polydimethylsiloxane(PDMS)flexible substrate.The prepared strain sensor had a large water contact angle of 153±2.83°and a small rolling angle of 8.5±1.04°,and exhibited excellent self-cleaning property.Due to the excellent superhydrophobicity,aqueous acid,salt,and alkali could quickly roll off the flexible strain sensor.In addition,the sensor showed excellent sensitivity(gauge factor(GF)of 5.4–7.35),wide sensing ranges(stretching:over 70%),good linearity(three linear regions),low hysteresis(hysteresis error of 4.8%),and a stable response over 100 stretching-releasing cycles.Moreover,the sensor was also capable of effectively detecting human motion signals like finger bending and wrist bending,showing promising application prospects in wearable electronic devices,personalized health monitoring,etc.Yulin Shang Bingzhen Zhang Jiyu Liu Chunwen Xia Xiaowei Yang Defeng Yan Jing Sun 2023Nanomanufacturing and Metrology2023,6,1:0
10Graft Copolymerization of Modified Oxidized Starch and Its ER Effect显示文摘To enhance the polarization of starch, the oxidized starch-BA-MAA-Gd copolymer was synthesized by radical graft copolymerization. The structure of the graft copolymer was determined by IR, scanning electron microscopy, state thermal analysis and X-ray diffraction. The electrorheological properties of the graft copolymer were also investigated. The results show that shear stress increases with the increase of the graft copolymer loadings and the electric field intensity.Liu Xueqing Yan Changhao Wu Liping Wu Defeng Qiu Guanming Zhang Ming 2006Journal of Rare Earths2006,24,5:0
11Spectral filtering effect on multi-pulsing induced by chirped fiber Bragg grating in dispersion-managed mode-locked Yb-doped fiber lasers显示文摘We numerically and experimentally investigate the multi-pulsing mechanism in a dispersion-managed mode-locked Ybdoped fiber laser.Multi-pulsing occurs primarily owing to the inherent filtering effect of the chirped fiber Bragg grating.The spectral filtering effect restricts the spectral broadening induced by self-phase modulation and causes extra loss,leading to a decreased pump power threshold for the multi-pulsing state.Numerical simulations show that multi-pulsing emerges at a lower pump power when the spectral filter bandwidth becomes narrower.In the experiment,the spectral width increases as the net cavity dispersion approaches zero.Pulses with wider spectral widths experience more loss from the spectral filtering effect,leading to a decreased pump power threshold for multi-pulsing.Therefore,the net cavity dispersion also has an impact on the multi-pulsing threshold.Based on this conclusion,we devise a strategy to obtain single-pulsing operation with the shortest pulse width and the highest pulse energy.Dongyu Yan Bowen Liu Defeng Zou Jie Guo Yuxi Chu Youjian Song Minglie Hu 2021High Power Laser Science and Engineering2021,9,3:0
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