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Chemical Research in Chinese Universities 2017年第4期33卷 660-665页

作者： ma jun Sichuan Province Institutions of Higher Education and Key Laboratory of Land Resources Evaluation and Monitoring in Southwest Ministry of Education Chengdu 610068 P. R. China

A Pt/γ-Al2O3-C heterogeneous catalyst with improved catalytic performance was successfully prepared. Bayberry talmin（BT）, an abundant natural plant polyphenol, was utilized to modifiy the surface of the Pt/γ-Al2O3 matrix and then stabilize Pt nanoparticles（NPs）. The catalyst was systematically and specifically characterized by a collec- tion of analytic tools including XRD, XPS, FTIR, TEM, and TG. It was found that the Pt NPs were envenly dispered on the γ-Al2O3-C matrix. Meanwhile, when the catalyst was applied for selective hydrogenation of cilmamalde- hyde（Cma） in the presence of KOH promoter in solvent, excellent catalytic performance was obtained. The selecti- vity to cinnamyl alcohol（CMO） reached 97.88% with 88.45% Cma conversion within 30 min in the presence of 0.037 mol/L KOH, without significant loss of catalytic activity even under cyclic measurements for 5 times. The excelleut catalytic performances should be ascribed predominantly to the uniform and stable dispersion ofPt NPs on the γ-Al2O3-C matrix and the excellent heat stability of BT.

关键词： Heterogeneous catalyst Pt/γ-Al2O3-C Barberry tannin Selective hydrogenation Ciunamaldehyde

A real-time online data acquisition system for Dragon-I linear induction accelerator

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Nuclear Science and Techniques 2017年第3期28卷 85-90页

作者： jun Wu Xiang Zhou Chen Yuan ze-Jie Yin State Key Laboratory of Particle Detection and Electronics and Department of Modern Physics University of Science and Technology of China Hefei 230026 China

An extensible high-speed accelerator data acquisition system(ADAS) for the Dragon-I linear induction accelerator has been developed. It comprises a ⅤⅪ crate, a controller, four data acquisition plug-ins, and a host computer. A digital compensation algorithm is used to compensate for the distortion of high-speed signals arising from longdistance transmission. Compared with the traditional oscilloscope wall, ADAS has significant improvements in system integration, automation, and reliability. It achieves unified management of data acquisition and waveform monitoring and performs excellently with a 107-ps high-accuracy trigger and 32-channel signal monitoring. In this paper, we focus on the system architecture and hardware design of the ADAS,realization of the trigger, and digital compensation algorithm.

关键词： ADAS LINAC Beam position monitor FPGA

Adsorption of phosphorus in sediment re-suspension under sudden expansion flow conditions

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Journal of Hydrodynamics 2013年第1期25卷 112-117页

作者： LIANG Wen WANG ze JIAO zeng-xiang WAN jun College of Mechanics and materials Hohai University State Key Laboratory for Turbulence and Complex System Department of Mechanics and Aerospace Engineering Peking University

Based on the study of hydraulic characteristics of the sudden expansion water flow of an annular flume, this paper determines the vertical velocity distribution and the turbulence intensity distribution in the mainstream and the recirculation regions to analyze the basic features of this flow field. The adsorption of the phosphorus in the sediment is studied by adding the bacteriostatic agent. The results show that the flow speed in the mainstream region is higher than that in the recirculation region. However, the turbulence intensity in the recirculation region increases more than that in the mainstream region. The adsorption of the phosphorus in the sediment includes the physisorption and the biosorption, and the former is stronger than the latter. With the biosorption in the phosphorus removal process, the phosphorus released by the sediment is mainly completed by the poly-P bacteria in the anaerobic condition. The adsorption of the phosphorus in the sediment in the mainstream region of a sudden expansion water flow is strong and stable, whereas the adsorption in the sediment in the recirculation region is largely fluctuated.

关键词： sudden expansion flow sediment phosphorus adsorption effect

Critical velocity in phosphorus exchange processes across the sediment-water interface

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Journal of Environmental Sciences 2013年第10期25卷 1966-1971页

作者： jun Wan ze Wang Zhijie Li Huiling Duan HezhongYuan State Key Laboratory for Turbulence and Complex System Department of Mechanics and Aerospace EngineeringCollege of Engineering Peking University College of Mechanics and materials Hohai University Research Center for Eco-Environmental Sciences Chinese Academy of Sciences School of Life Sciences Nanjing University

Sediments are ultimate sinks of nutrients in lakes that record the pollution history evolutionary processes, and anthropogenic activities of a lake. However, sediments are considered as inner sources of environmental factor changes such as the variation in hydrodynamic conditions because of the nutrients they release. How does this process happen？ This study investigates a typical nutrient phosphorus （P） exchange among sediment, suspended particle matter （SPM）, and water. Compared with numerical and experimental studies, this study confirms that the critical velocity that occurs at a lower flow rate state exists in the range of 7 to 15 crn/sec. Critical velocity below the critical flow rate promotes the migration of particulate phosphorus （PP） to the SPM. On the other hand, critical velocity above the critical flow rate promotes the release of PP in water.

关键词： abrupt expansion flow critical velocity lake eutrophication phosphorus exchange

Intermediate mass dilepton production in a chemically equilibrating quark-gluon matter

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Nuclear Science and Techniques 2003年第1期14卷 53-55页

作者： HE ze-jun ZHANG Jia-Ju 等 CCAST（worldLaboratory)P.O.Box8730 Beijing100080 ShanghaiInstituteofnuclearResearch theChineseAcademyofSciencesShanghai201800

We find that in a chemically equilibrating baryon-rich quark-gluon matter, due to the slow cooling rate, high initial temperature, large gluon density as well as large fusion cross section ofin the intermediate mass region, the gluon fusion provides a dominant contribution to dileptons with intermediate masses, resulting in the significant enhancement of intermediate mass dileptons.

关键词：高能重离子碰撞 RHZC 放射性原子核化学平衡 QGM LHC TES

Three Types of Isocoumarins with Unusual Carbon Skeletons from Artemisia dubia var. subdigitata and Their Antihepatoma Activity

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Chinese Journal of Chemistry 2024年第16期42卷 1901-1912页

作者： Ke-Xin Yang Tian-ze Li Yun-Bao ma Yong-Cui Wang Feng-Jiao Li Ji-jun Chen State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China

Ten novel isocoumarins,including four pairs of enantiomers,were isolated from Artemisia dubia ***(Asteraceae).Compounds 1,2 and 3a/3b possessed a unique 6/6/6-tricyclic system comprising an unusual 1-(2-methylcyclohexyl)propan-1-one moiety fused with isocoumarin core *** 4a/4b were characterized as an unexpected 2,5-dimethylcyclohexan-1-one scaffold,and compounds 5a/5b and 6a/6b were rare 1,*** structures and absolute configurations were elucidated through spectroscopic data,X-ray crystallography,ECD and NMR calculations with DP4+*** biosynthetic pathways were proposed from the naturally occurring *** pharmacological analysis suggested that the targets of compound 1 were significantly enriched in the cell cycle and Pl3K-Akt signaling *** molecular docking revealed that compound 1 had high binding affinity with CDK2(total score:6.8717).Furthermore,compounds 1 and 2 exhibited inhibitory activity on three human hepatoma cell lines,with inhibitory ratios of 85.1% and 84.5%(HepG2),88.2% and 87.3%(Huh7),and 69.2% and 69.1%(SK-Hep-1)at 200μmol·L^(-1),respectively.

关键词： Artemisia dubia var.subdigitata Isocoumarins Antihepatoma activity Cancer Natural products X-ray diffraction

The Changing of Common Priors in Sequential Auctions

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Journal of Systems Science & Complexity 2016年第5期29卷 1342-1357页

作者： QIAO Heng ma jun School of Economics Central University of Finance and Economics Business School University of International Business and Economics

In sequential auctions the phenomenon of declining prices is often observed, which in theory can be represented by a supermartingale. This paper employs the perspective that bidders' values may change over stages and the common priors are sequentially adjusted by the remaining bidders. It is shown that the declining price sequence can be explained by the adjustment of common priors between auctions. The adjustment of common priors is characterized by stochastic orders. Sufficient and necessary conditions for a supermartingale price sequence are derived.

关键词： First-price sealed-bid auction private-value paradigm sequential auctions.

不同荷载作用下五边形石墨烯的变形破坏机理研究

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原子与分子物理学报 2025年第6期42卷 51-57页

作者：赵泽若韩同伟李仁葛峻铭王嘉越江苏大学土木工程与力学学院镇江212013

五边形石墨烯是一种完全由碳五元环组成的准二维的亚稳态碳结构,在不同载荷作用下其变形破坏机理仍需进一步研究.本文基于ReaxFF反应力场采用分子动力学方法模拟研究了五边形石墨烯的拉伸、剪切和纳米压痕破坏过程,得到了五边形石墨烯... 详细信息

五边形石墨烯是一种完全由碳五元环组成的准二维的亚稳态碳结构,在不同载荷作用下其变形破坏机理仍需进一步研究.本文基于ReaxFF反应力场采用分子动力学方法模拟研究了五边形石墨烯的拉伸、剪切和纳米压痕破坏过程,得到了五边形石墨烯的拉伸和剪切应力-应变曲线以及压入载荷-位移曲线,系统分析了五边形石墨烯的变形破坏机理,并验证了五边形石墨烯在不同载荷作用下是否表现出塑性变形特征的一致性问题.研究结果表明,通过拉伸或纳米压入等不同加载方式均可准确测出五边形石墨烯的本征力学性能参数,其杨氏模量265.4~285.1 N/m,与第一性原理计算结果一致.研究还发现,五边形石墨烯在拉伸、剪切和纳米压痕过程中均会出现不可逆的塑性变形特征,而引起塑性变形的原因是由于不可逆的碳五元环向碳多元环结构的转变.以上研究结果可为基于五边形石墨烯的微/纳米机电系统的实际应用提供重要指导.

关键词：五边形石墨烯变形破坏机理分子动力学

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Possible Contribution of mature γ-ray Pulsars to Cosmic-ray Positrons

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Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 87-95页

作者： Quan-Gui Gao ze-jun Jiang Li Zhang National Astronomical Observatories / Yunnan Observatories Chinese Academy of Sciences Kunming 650011 Department of Physics Yunnan University Kunming 650091

We restudy the possible contribution of mature gamma-ray pulsars to cosmic ray positrons based on the new version of outer gap model. In this model, the inclination angle and average properties of the outer gap are taken into account, and more mature pulsars can have the outer gap and emit high energy photons. Half of the primary particles in the outer gaps will flow back toward the star surface and emit synchrotron photons, which can produce electron/positron pairs by the cascade of pair production. Some of these pairs will escape from the light cylinder and be accelerated to relativistic energies in the pulsar wind driven by low-frequency electromagnetic waves. Using a Monte Carlo method, we obtain a sample of mature gamma-ray pulsars and then calculate the production of the positrons from these pulsars. The observed excess of cosmic positrons can be well explained by this model.

关键词： stars pulsars general - acceleration of particles - ISM cosmic rays

Adiabatic correction for the esterification of acetic anhydride by methanol via accurate kinetics

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Chinese Journal of Chemical Engineering 2018年第9期26卷 1954-1959页

作者： ze Dong Liping Chen Yingying ma Haoliang Peng Wanghua Chen Nanjing University of Science & Technology School of Chemical Engineering Solvay (China) Co. Ltd.

In the field of adiabatic correction for complex reactions,a simple one-stage kinetic model was used to estimate the real reaction ***,this assumption simplified the real process,inevitably generated inaccurate or even unsafe ***,it was necessary to find a new correction method for complex *** this work,esterification of acetic anhydride by methanol was chosen as an object reaction of *** reaction was studied under different conditions by Reaction Calorimeter(RC1).Then,Thermal Safety Software(TSS)was used to establish the kinetic model and estimate the parameters,where,activation energies for three stages were67.09,81.02,73.77 kJ?mol^(-1)respectively,and corresponding frequency factors in logarithmic form were 16.05,19.59,15.72 s^(-1).In addition,two adiabatic tests were performed by Vent Sizing Package2(VSP2).For accurate correction of VSP2 tests,a new correction method based on Enhanced Fisher method was *** with kinetics,adiabatic correction of esterification reaction was *** this research,accurate kinetic parameters for a three-step kinetic model of the esterification reaction were ***,the correlation coefficients between simulated curves and corrected curves were 0.976 and 0.968,which proved the accuracy of proposed new adiabatic correction *** on this new method,conservative corrected results were able to be acquired and be applied in safety assessment.

关键词： Adiabatic correction Kinetics New method Complex reaction Esterification Model reaction