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Lipschitz Continuous Solutions to the Cauchy Problem for Quasi-linear Hyperbolic Systems

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Chinese Annals of Mathematics,Series B 2012年第4期33卷 521-536页

作者： xiang chen School of Mathematical Sciences Fudan University Shanghai 200433 China.

Lipschitz continuous solutions to the Cauchy problem for 1-D first order quasi-linear hyperbolic systems are considered. Based on the methods of approximation and integral equations, the author gives two definitions o... 详细信息

关键词： First order quasi-linear hyperbolic systems Lipschitz continuous solution Cauchy problem Existence and uniqueness

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基于干涉和实时前馈实现三个量子节点的纠缠

原子与分子物理学报 2025年第4期42卷 113-120页

作者：刘艳红陈伟李雁翔太原师范学院物理系晋中030619 太原师范学院计算机科学与技术学院晋中030619 山西北方机械制造有限责任公司太原030009

纠缠多个空间分离的远程量子节点是构建量子信息网络的基础,不仅如此,多量子节点间的纠缠亦可应用于分布式量子计算和量子精密测量等,实现更高纠缠度的多量子节点间纠缠势在必行.文中基于干涉和实时前馈,借助于腔增强通过采用受激拉曼... 详细信息

纠缠多个空间分离的远程量子节点是构建量子信息网络的基础,不仅如此,多量子节点间的纠缠亦可应用于分布式量子计算和量子精密测量等,实现更高纠缠度的多量子节点间纠缠势在必行.文中基于干涉和实时前馈,借助于腔增强通过采用受激拉曼散射机制实现三个远距离原子系综的纠缠.该方案中只需要三套腔增强原子系统,光学谐振腔增强了光和原子之间的相互作用,使得通过受激拉曼散射产生的斯托克斯光场和反斯托克斯光场的效率得到提高,实现了高纠缠度的光与原子纠缠.在此前提下,基于斯托克斯光场的干涉和实时前馈实现三个远程原子节点间的纠缠.这种方法可以扩展到更大规模,甚至更加复杂的量子信息网络中,从而在量子信息科学中具有潜在的应用.

关键词：原子系综纠缠干涉实时前馈受激拉曼散射

Linkage between water soluble organic matter and bacterial community in sediment from a shallow, eutrophic lake, Lake Chaohu, China

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Journal of Environmental Sciences 2020年第12期32卷 39-46页

作者： Changming Yang Jiliang Sun yingying chen Jing Wu Yulai Wang Key Laboratory of Yangtze River Water Environment of the Ministry of Education Tongji UniversityShanghai 200092China Shanghai BaoSen Environmental Technology Co. Ltd.Shanghai 200439China School of Energy and Environment Anhui University of TechnologyMaanshan City 243002China

Lacustrine sediment played important roles in migration and transformation of its water soluble organic matter(WSOM), and the source and composition of WSOM would affect water trophic status and the fate of pollutants. However, we know little about the pathway of WSOM transformation and its driving bacterial communities in lacustrine sediment. In the present study, we investigated the spatial distribution patterns of sediment WSOM and its fluorescent fractions across Lake Chaohu using fluorescence spectroscopy, and explored WSOM compositional structure through our proposed calculated ratios. In addition, we also analyzed sediment bacterial community using Illumina sequencing technology, and probed the possible pathway of sediment WSOM transformation under the mediate of indigenous bacteria. Our results showed that the inflowing rivers affected the spatial distribution patterns of WSOM and its five fractions(including tyrosine-, tryptophan-, fulvic acid-, humic acid-like substances and soluble microbial productions), and sediment WSOM originated from fresh algae detritus or bacterial sources. In parallel, we also found that Proteobacteria(mainly γ-Proteobacteria and δ-Proteobacteria), Firmicutes(mainly Bacilli), Chloroflexi, Acidobacteria, Planctomycetes and Actinobacteria dominate sediment bacterial community. Furthermore, these dominant bacteria triggered sediment WSOM transformation, specifically, the humic acid-like substances could be converted into fulvic acid-like substances, and further degraded into aromatic protein-like and SMP substances. In addition, our proposed ratios(P-L:H-L, Ar-P:SMP and H-L ratio), as supplementary tool, were effective to reveal WSOM composition structure. These results figured out possible pathway of WSOM transformation, and revealed its microbial mechanism in lacustrine sediment.

关键词： Eutrophic lake DOM transformation Bacterial community EEMs-FRI Illumina sequencing

Characteristics and source apportionment of PM_(2.5) under the dual influence of the Spring Festival and the COVID-19 pandemic in Yuncheng city

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Journal of Environmental Sciences 2023年第3期125卷 553-567页

作者： chen Zhang yingying Zhang Xingang Liu Yafei Liu chenlu Li State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Beijing Capital Air Environmental Science&Technology Co. Ltd.Beijing 100176China

Based on the online and membrane sampling data of Yuncheng from January 1st to February 12th,2020,the formation mechanism of haze under the dual influence of Spring Festival and COVID-19 (Corona Virus Disease) was *** capacity,chemical composition,secondary transformation,source apportionment,backward trajectory,pollution space and enterprise distribution were *** wind speed,high humidity and small atmospheric capacity inhibited the diffusion of air *** severe pollution processes occurred during the period,and the pollution degree was the highest around the Spring *** light,medium and heavy pollution periods,the proportion of SNA (SO_(4)^(2-),NO_(3)-and NH_(4)^(+)) was 59.6%,56.0%and 54.9%,respectively,which was the largest components of PM_(2.5);the[NO_(3)-]/[SO_(4)^(2-)]ratio was 2.1,1.5 and 1.7,respectively,indicating that coal source had a great influence;the changes of NOR (nitrogen oxidation ratio,0.44,0.45,0.61)and SOR (sulphur oxidation ratio,0.40,0.49,0.65) indicated the accumulation of secondary aerosols with increasing *** coal combustion,motor vehicle,secondary inorganic sources and industrial sources contributed 36.8%,26.59%,11.84%and 8.02%to PM_(2.5)masses,*** trajectory showed that the influence from the east was greater during the Spring Festival,and the pollutants from the eastern air mass were higher,which would aggravate the *** and Spring Festival had a great impact on heavy pollution *** some work could not operate due to the impact of the COVID-19 epidemic,the emission of pollutants did not reduce much.

关键词： PM_(2.5) COVID-19(Corona Virus Disease) Yuncheng Secondary conversion Source apportionment

Molecular characterization of transformation and halogenation of natural organic matter during the UV/chlorine AOP using FT-ICR mass spectrometry

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Journal of Environmental Sciences 2021年第4期33卷 24-36页

作者： Xiaoxue Ruan yingying xiang Chii Shang Shuangshuang cheng Jingfu Liu Zhineng Hao Xin Yang School of Environmental Science and Engineering Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation TechnologySun Yat-sen UniversityGuangzhou 510275China Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Hong Kong Branch of Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution The Hong Kong University of Science and TechnologyHong KongChina State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

UV/chlorine process,as an emerging advanced oxidation process(AOP),was effective for removing micro-pollutants via various reactive radicals,but it also led to the changes of natural organic matter(NOM)and formation of disinfection byproducts(DBPs).By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS),the transformation of Suwannee River NOM(SRNOM)and the formation of chlorinated DBPs(Cl-DBPs)in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark *** comparison to dark chlorination,the involvement of Cl O·,Cl·,and HO·in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity(AI mod)value and DBE(double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic ***,more compounds which contained only C,H,O,N atoms(CHON)were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions.A total of 833 compounds contained C,H,O,Cl atoms(CHOCl)were observed after the UV/chlorine AOP,higher than 789 CHOCl compounds in dark chlorination,and one-chlorine-containing components were the dominant *** different products from chlorine substitution reactions(SR)and addition reactions(AR)suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher ***-chlorination further caused the cleavages of NOM structures into small molecular weight compounds,removed CHON compounds and enhanced the formation of *** results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.

关键词： UV/chlorine AOP Disinfection byproducts(DBPs) Natural organic matter(NOM) FT-ICR MS Water treatment

Design and numerical analysis of serpentine microchannel integrated with inner-wall ridges for enhanced droplet mixing

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Science China(Technological Sciences) 2023年第2期66卷 560-573页

作者： CAO xiang chen YongPing Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application School of Environmental Science and EngineeringSuzhou University of Science and TechnologySuzhou 215009China

A numerical model is developed for three-dimensional droplet mixing in serpentine microchannels with inner-wall ridges(referred to as SMR microchannels).The underlying mechanisms of mixing in SMR microchannels are revealed,and the effects of the ridge width and ridge number on mixing inside droplets of different sizes are *** results indicate that SMR microchannels are capable of enhancing the mixing efficiency by 3.6%–12.5%compared with that in smooth serpentine microchannels,particularly when the droplet length is larger than the microchannel width and the width ratio of the ridge to the microchannel is 0.25–*** above mixing enhancement is determined by two main factors:the combined effects of the vortex pair and reverse flow,and non-horizontal ***,when the width ratio is 1,there is a maximum 16.0%increase in mixing efficiency for small droplets with a length equal to the microchannel ***,for small droplets,mixing in an SMR microchannel is worse than in a smooth serpentine microchannel when the width ratio is less than *** increasing the ridge number,when the width ratio is 0.25,the mixing efficiency is reduced for small droplets but increased for larger droplets.

关键词： droplet mixing serpentine microchannel ridge microfluidics

Toward the minimum vertex cover of complex networks using distributed potential games

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Science China(Information Sciences) 2023年第1期66卷 244-263页

作者： Jie chen xiang LI Adaptive Networks and Control Lab Department of Electronic Engineering Fudan University Institute of Complex Networks and Intelligent Systems Shanghai Research Institute for Intelligent Autonomous SystemsTongji University

Vertex cover of complex networks is essentially a major combinatorial optimization problem in network science, which has wide application potentials in engineering. To optimally cover the vertices of complex networks, this paper employs a potential game for the vertex cover problem, designs a novel cost function for network vertices, and proves that the solutions to the minimum value of the potential function are the minimum vertex covering(MVC) states of a general complex network. To achieve the optimal(minimum) covering states, we propose a novel distributed time-variant binary log-linear learning algorithm,and prove that the MVC state of a general complex network is attained under the proposed optimization algorithm. Furthermore, we estimate the upper bound of the convergence rate of the proposed algorithm,and show its effectiveness and superiority using numerical examples with representative complex networks and optimization algorithms.

关键词： minimum vertex cover Nash equilibrium convergence rate scale-free network random graph

Studies of short-time and high-temperature annealing and magnetic property of LaFe_(11.4)Si_(1.6) compound

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Acta Metallurgica Sinica(English Letters) 2011年第5期24卷 390-398页

作者： xiang chen Yungui chen Yongbo TANG School of Materials Science and Engineering Sichuan University Chengdu 610065 China Department of Physics and Electronic Informational Engineering Neijiang Teachers College Neijiang 641002 China

The LaFe11.4Si1.6 compounds are prepared by arc-melting and then annealed at different high temperatures from 1323 K （5 h） to 1623 K （2 h）. The powder X-ray diffraction （XRD） and microstructure observations show that large amount of 1：13 phase begins to appear in the LaFe11.4Si1.6 compound annealed at 1423 K （5 h）. In the temperature range from 1423 K to 1523 K, the α-Fe and LaFeSi phases rapidly decrease to form 1：13 phase. The LaFeSi phase is rarely observed by XRD when the as-cast compound is annealed at 1523 K （5 h）. With annealing temperature increasing to 1573 K, LaFeSi phase is detected again in LaFe11.4Si1.6 compound. In LaFe11.4Si1.6 compounds annealed at 1523 K （5 h）, at 1373 K （2 h）＋1523 K （5 h）, and 1523 K （7 h）＋1373 K （2 h）, the impurity phases including small amount of α-Fe and LaFeSi phase reduce in turn. The magnetic measurement shows that LaFe11.4Si1.6 compounds annealed by above three processes keep the first-order of magnetic transition behavior, and Tc are both at about 200 K. But the values of the maximal ASM（T, H） of has large difference, they are 9.94, 12.66, and 13.96 J/（kg.K） under a magnetic field of 0- 2 T, respectively.

关键词： LaFe11.4Sil.6 compound Short-time and high-temperature an-nealing Phase transition Magnetic property

Detailed Inventory Mapping and Spatial Analyses to Landslides Induced by the 2013 Ms 6.6 Minxian Earthquake of China

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Journal of Earth Science 2016年第6期27卷 1016-1026页

作者： yingying Tian Chong Xu Xiwei Xu Jian chen Key Laboratory of Active Tectonics and Volcano Institute of GeologyChina Earthquake Administration School of Engineering and Technology China University of Geosciences

On July 22, 2013, an earthquake （Ms 6.6） occurred in Minxian, Gansu Province of China, causing a large number of landslides. Based on high resolution remote sensing images before and after this event, we made the visual interpretation to these coseismic landslides, and prepared a detailed inventory. The inventory registers totally 6 478 landslides in the study area. Of them, 3 322 landslides are larger than 100 m2. Based on 5 m resolution DEM, these landslides were used to perform spatial analyses using landslide number density （LND） and landslide area percentage （LAP）. The results show that the highest LND and LAP values are in the elevation range of 2 300-2 500 m and steeper slopes. Slopes facing E, SE, S and SW directions, slopes with larger absolute curvature values, ridges, scopes of gravel beds of Late Pleistocene （Qp） and the VIII-degree seismic intensity are more prone to sliding with high LND and LAP values. The largest LND and LAP values are in the scopes of 0.08 and 0.24 g, respectively. According to landslide distribution, we infer that F2-2 branch of Lintan-Dangchang fault is the seismogenic fault. With the increasing distances to this branch fault and drainages, LND and LAP values tend to decrease.

关键词： Minxian Earthquake landslide inventory spatial analyses landslide number density (LND) landslide area percentage (LAP).