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A new era of flood control strategies from the perspective of managing the 2020 Yangtze River flood

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Science China Earth Sciences 2021年第1期64卷 1-9页

作者： Jun XIA jin chen State Key Laboratory of Water Resources and Hydropower Engineering Sciences Wuhan UniversityWuhan 430072China Wuhan University Yangtze River Academy of SciencesChangjiang Water Resources Commission of the Ministry of Water ResourcesWuhan 430015China

Flood control of the Yangtze River is an important part of China’s national water *** July 2020,due to continuous heavy rainfall,the water levels along the middle-lower reaches of the Yangtze River and major lakes constantly exceeded the warning levels,in which Taihu Lake exceeded its highest safety water level and some stations of Poyang Lake reached their highest water levels in its *** August 2020,another huge flood occurred in the Minjiang River and the Jialing River in the upper Yangtze River,and some areas of Chongqing Municipality and other cities along the rivers were inundated,resulting in great pressure on flood control and high disaster *** 2020 Yangtze River flood has received extensive media coverage and raised concerns on the roles of the Three Gorges Dam and other large reservoirs in flood *** we analyze the changes in the pattern of the Yangtze River flood control by comparing the strategies to tackle the three heavy floods occurring in 1954,1998,and *** propose that the overall strategy of the Yangtze River flood control in the new era should adhere to the principle of"Integration of storage and drainage over the entire Yangtze River Basin,with draining floods downstream as the first priority"by using both engineering and non-engineering *** the basis of embankments,the engineering measures should use the Three Gorges Dam and other large reservoirs as the major regulatory means,promote the construction of key flood detention areas,keep the floodways clear,and maintain the ecosystem services of wetlands and *** terms of non-engineering measures,we should strengthen adaptive flood risk management under climate change,standardize the use of lands in flood detention areas,give space to floods,and promote the implementation of flood risk maps and flood insurance *** ultimate goal of this new flood control system is to enhance the adaptability to frequent floods and increase the resilience to extre

关键词： The 2020 Yangtze River flood Yangtze River Flood Control System Three Gorges Dam Protection of wetlands and shoals Non-engineering measures

Dynamic Monte Carlo Simulation on Polymerization of Encapsulant

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Chinese Journal of Polymer Science 2019年第2期37卷 157-163页

作者： jin chen Jiong-Hua Xiang Department of Physics Research Institute for Soft Matter and Biominetics Xiamen University Department of Chemical Engineering Shanghai Jiao Tong University

Based on the preparative experiments of the light-emitting diode(LED) encapsulant, three types of monomer models with different functional groups are carried out to study the polymerization process by dynamic Monte Carlo(DMC) simulation and bond fluctuation model(BFM). We calculate the degree of polymerization, the radius of gyration and the frequency of void spheres to discuss the polymerization process, the molecular size and the spatial distribution at different volume fractions and proportions. Our results are in agreement with Grest's decay rate and Flory's scale law. Simulations show that the polymerization process depends on the appropriate volume fraction and proportion exceedingly, and the volume contraction in the polymerization process can also be observed in this *** investigations could provide some insights into the understanding of the polymerization process of the encapsulant and help us to adjust the parameters in later experiments.

关键词： Dynamic Monte Carlo(DMC)simulation Bond fluctuation model(BFM) LED encapsulant

Study on open charm hadron production and angular correlation in high-energy nuclear collisions

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Nuclear Science and Techniques 2021年第1期32卷 10-16页

作者： Hai Wang jin-Hui chen Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China

We study the production and angular correlationof charm hadrons in hot and dense matter produced in high-energy nuclear-nuclear collisions within a multiphasetransport model(AMPT).By triggering additional charm-anticharm quark pair production in the AMPT,the modeldescribes the D^0 nuclear modification factor in the low andintermediate pr regions in Au+Au collisions at√VSNN=200 GeV reasonably *** exploration of the D^0 pair azimuthal angular correlation for different centralitiesshows clear evolution from low-multiplicity to high-mul-tiplicity events,which is associated with the number ofcharm quark interactions with medium partons duringAMPT transport.

关键词： Heavy-ion collision Heavy flavor Nuclear modification factor Two-particle correlations

Anisotropy flows in Pb-Pb collisions at LHC energies from parton scatterings with heavy quark trigger

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Nuclear Science and Techniques 2022年第2期33卷 14-20页

作者： Hai Wang jin-Hui chen Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China

By implementing an additional heavy quark-antiquark pair production trigger in a multiphase transport(AMPT)model,we study the effect on anisotropy flows of identified particles with a focus on charged particles and quarkonium(J/ΨandΥ).A systematic increase in the collision rate for active partons in the AMPT model with such an implementation has been *** leads to a slight increase of identified particles anisotropy flows as a function of transverse momentum(pT)and rapidity,and gives a better description of the experimental data of elliptic flow toward larger *** approach provides an efficient way to study the heavy quark dynamics in the AMPT model at LHC energies.

关键词： Heavy-ion collision Quark-gluon plasma Quarkonium Collective flow

Lagrangian statistics in isotropic turbulent flows with deterministic and stochastic forcing schemes

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Acta Mechanica Sinica 2015年第1期31卷 25-31页

作者： jin-Cai chen Guo-Dong jin Jian Zhang LNM Institute of MechanicsChinese Academy of Sciences

Artificial input of energy into the flow is neces sary to create and maintain a statistically stationary isotropic turbulence for sampling in studying the statistics. Due to the nonlinear coupling among different Fourier modes through the triadic interaction, whether or not various forc ing schemes affect the statistics in turbulence is an impor tant and open question. We present detailed comparison of Lagrangian statistics of fluids particles in forced isotropic turbulent flows in 1283, 2563, and 5123 simulations, with Taylorscale Reynolds numbers in the range of 64-171, us ing a deterministic and a stochastic forcing scheme, respec tively. Several Lagrangian statistics are compared, such as velocity and acceleration autocorrelations, and moments of Lagrangian velocity increments. The differences in the La grangian statistics obtained from the two forcing schemes are shown to be small, indicating that the isotropic forcing schemes used have little effects on the Lagrangian statistics in the isotropic turbulence.

关键词： Isotropic turbulence Deterministic forcingscheme Stochastic forcing scheme Lagrangian statisticalquantities

Design optimization of 3.9GHz fundamental power coupler for the SHINE project

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Nuclear Science and Techniques 2021年第11期32卷 174-190页

作者： Zhen-Yu Ma jin-Fang chen Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The third harmonic superconducting cryomodule is being designed for the Shanghai High repetition rate XFEL and Extreme light facility(SHINE)project,which is under *** contrast to the European X-ray Free Electron Laser(E-XFEL)project,the 3.9 GHz cryomodules in the SHINE project will operate in the continuous wave regime with higher radio frequency average power for both cavities and *** propose a 3.9 GHz fundamental power coupler with an adjustable antenna length,for satisfying the SHINE project ***,we describe the 3.9 GHz fundamental power coupler's design considerations and power requirements for various operating modes of the SHINE *** also present the results of the radio frequency simulation and optimization,including the studies on multipacting and thermal analysis of the proposed 3.9 GHz coupler.

关键词： 3.9 GHz fundamental power coupler Third harmonic cavity Superconducting cryomodule XFEL and extreme light facility(SHINE)Linac

MapReduce rationality verification based on object Petri net

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Journal of Systems Engineering and Electronics 2019年第5期30卷 861-874页

作者： DING Zeliu GUO Deke chen Xi chen jin School of Electronics Engineering Navy University of EngineeringWuhan 430033China Research Center of Evaluation and Demonstration Academy of Military SciencesBeijing 100091China College of Systems Engineering National University of Defense TechnologyChangsha 410073China School of Computer Science McGill UniversityMontreal H3A 2A7Canada

As a powerful distributed data processing mechanism,MapReduce supports abundant parallel applications that process massive data on computer *** process the massive data efficiently and correctly,a rational design for the MapReduce procedure is *** irrational MapReduce procedure can cause great waste of computing resources and even paralyze the execution *** the wide application of MapReduce,the unavoidable drawback of irrational MapReduce procedures becomes increasingly *** solve this problem,a method for verifying the rationality of a MapReduce procedure before executing it on a computer cluster is *** method constructs the rationality criteria for MapReduce,and then studies an automatic approach for modelling MapReduce with an executable model object Petri net(OPN).Finally,the approaches for automatically identifying the rationality criteria by analyzing the consequence of model execution is *** results from extensive case studies demonstrate that the proposed method is feasible and effective.

关键词： MapReduce rationality verification cloud computingframework

ELECTROCHEMICAL KINETICS ON BULK CONCENTRATE SEPARATION OF PYRITE AND GALENA

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中国有色金属学会会刊：英文版 1999年第2期9卷 164-169页

作者： Feng, Qiming chen, Jianhua Lu, Yiping chen, jin Central South Univ of Technology Changsha China

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关键词： galenapyriteelectrochemical floatationelectrochemical reduction kinetics

Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves

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Journal of Environmental Sciences 2011年第4期23卷 624-632页

作者： Yanshan Cui jin Fu Xiaochen chen College of Resources and Environment Graduate University of Chinese Academy of Sciences Beijing 100049 China.

Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments （1-, 3-, and 6-month） were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition （1% and 3%） and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable （F1）, precipitated with carbonates （F2）, bound to Fe/Mn oxides （F3） and bound to organic matter （F4） fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction （F5） of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.

关键词： lead cadmium speciation bioaccessibility decomposition