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Highly Efficient Lattice Boltzmann Model for Compressible Fluids:Two-Dimensional Case

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Communications in Theoretical Physics 2009年第10期52卷 681-693页

作者： CHEN Feng XU Ai-Guo ZHANG Guang-Cai gan yan-biao CHENG Tao LI Ying-Jun China University of Mining and Technology （Beijing） Beijing 100083 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O. Box 8009-26 Beijing 100088 China North China Institute of Aerospace Engineering Langfang 065000 China

We present a highly efficient lattice Boltzmann model for simulating compressible flows. This model is based on the combination of an appropriate finite difference scheme, a 16-discrete-velocity model [Kataoka and Tsutahara, Phys. Rev. E 69 （2004） 035701（R）] and reasonable dispersion and dissipation terms. The dispersion term effectively reduces the oscillation at the discontinuity and enhances numerical precision. The dissipation term makes the new model more easily meet with the yon Neumann stability condition. This model works for both high-speed and low-speed flows with arbitrary specific-heat-ratio. With the new model simulation results for the well-known benchmark problems get a high accuracy compared with the analytic or experimental ones. The used benchmark tests include （i） Shock tubes such as the Sod, Lax, Sjogreen, Colella explosion wave, and collision of two strong shocks, （ii） Regular and Mach shock reflections, and （iii） Shock wave reaction on cylindrical bubble problems. With a more realistic equation of state or free-energy functional, the new model has the potential tostudy the complex procedure of shock wave reaction on porous materials.

关键词： lattice Boltzmann method compressible flows specific-heat-ratio von Neumann stability analysis

Prevalence and Influencing Factor Analysis of Typhoid/Paratyphoid Fever—China,2011-2020

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China CDC weekly 2024年第21期6卷 493-498页

作者： Shumei Huang Meiying yan biao Kan School of Public Health Shandong UniversityJinan CityShandong ProvinceChina National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina

Introduction:Over the last 12 years,there has been a consistent decline in the cases of typhoid/paratyphoid fever in *** the epidemiological patterns of these diseases in various provincial-level administrative divisions(PLADs)and examining potential influencing factors can provide crucial information for implementing successful control ***:In this study,we analyzed the cases and incidence rates of typhoid/paratyphoid fever reported in various PLADs of China from 2011 to 2022,along with exploring potential influencing *** initially studied spatial shifts in the incidence rates through centroid shift *** variations in typhoid/paratyphoid fever onset were examined using *** autocorrelation analysis was utilized to understand the spatial correlations among different *** assess potential factors,we utilized a generalized estimating equations model that integrated spatial lag effects and sequence comparison ***:The study identified significant geographical clustering of typhoid/paratyphoid fever cases in southwestern China.A decrease in incidence rates in the west resulted in a movement of the disease center towards the *** incidence occurred during warmer seasons,highlighting the seasonal pattern of the *** such as meteorological conditions and socioeconomic status were probable influencers of typhoid/paratyphoid ***:The geographical and temporal spread of typhoid/paratyphoid fever can be impacted by meteorological and socioeconomic *** economic conditions,particularly in regions with high disease prevalence,could aid in the prevention and management of these fevers.

关键词： prevention utilized meteorological

A Sustainable Dual Cross‑Linked Cellulose Hydrogel Electrolyte for High‑Performance Zinc‑Metal Batteries

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Nano-Micro Letters 2024年第6期16卷 63-75页

作者： Haodong Zhang Xiaotang gan Yuyang yan Jinping Zhou Hubei Engineering Center of Natural Polymers‑Based Medical Materials Key Laboratory of Biomedical Polymers of Ministry of EducationCollege of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072People’s Republic of China Zhongnan Hospital of Wuhan University Institute of Hepatobiliary Diseases of Wuhan UniversityTransplant Center of Wuhan UniversityWuhan 430072People’s Republic of China

Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy ***,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion *** address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions ***,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.

关键词： Cellulose Dual cross-linked Aqueous rechargeable Zn-metal batteries Hydrogel electrolyte

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超长射流等离子体在介质管内的传播机制

发光学报 2016年第5期37卷 597-602页

作者：李永辉董丽芳甘延标北华航天工业学院基础部河北廊坊065000 河北大学物理科学与技术学院河北保定071002

利用交流驱动的单针射流等离子体装置,在介质管内产生了可以沿着介质管任意弯曲的超长射流等离子体,且可以喷射到介质管外的空气当中。利用高速相机对介质管内等离子体的传播过程进行拍照,研究了这种超长等离子体在介质管内的传播机制... 详细信息

利用交流驱动的单针射流等离子体装置,在介质管内产生了可以沿着介质管任意弯曲的超长射流等离子体,且可以喷射到介质管外的空气当中。利用高速相机对介质管内等离子体的传播过程进行拍照,研究了这种超长等离子体在介质管内的传播机制。研究发现,该装置在大气压下产生的等离子体长度可以达到约85 cm。在外加电压的正、负半周期,介质管内的等离子体具有不同的形貌和传播机制。正半周等离子体是以"等离子子弹"的方式向前传播,而负半周是以连续模式向前传播。分析发现,放电形成的空间电荷与介质管壁上的壁电荷之间形成的电场,是影响介质管内等离子体传播的主要因素。

关键词：射流等离子体单针放电等离子子弹

Abiotic transformation of chlorinated organics at the active surface of iron-bearing minerals in soils and sediments

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Science China Technological Sciences 2024年第10期67卷 2991-3008页

作者： LI XuXin yan Chen ZENG YuXi LI WenBin PENG TianWei SONG biao ZHOU ChengYun College of Environmental Science and Engineering Hunan University Key Laboratory of Environmental Biology and Pollution Control (Hunan University) Ministry of Education

Chlorinated organic compounds are emerging pollutants of widespread concern because of their toxicity, bioaccumulation,persistence, and lack of adequate regulatory measures. Their abiotic transformation, facilitated by iron-bearing minerals, is critical to their natural dissipation in soils and sediments. However, further exploration is needed to understand their underlying mechanisms and potential engineering applications under different redox conditions. This paper reviews the abiotic transformation behaviors and mechanisms of chlorinated organics at the active surface of iron-bearing minerals under anoxic and oxic conditions and summarizes the strategies for enhancing the abiotic transformation efficiency of chlorinated organics. The abiotic transformation rate under oxic conditions can be a few orders of magnitude higher than that under anoxic conditions. Under anoxic conditions, chlorinated organics undergo reductive dechlorination through reductive elimination, hydrogenolysis, dehydrohalogenation, and nucleophilic substitution. A close relationship between the abiotic transformation of chlorinated organics and the production of hydroxyl radicals by iron-bearing minerals under oxic conditions was discovered. Synthetic active iron-bearing minerals, carbonaceous materials, and biological synergy can facilitate abiotic dechlorination under anoxic conditions. Meanwhile, the regulation of redox conditions, the introduction of ligands, and the utilization of coexisting anions are proposed to enhance oxidative degradation. This study is expected to improve the comprehension of the abiotic degradation of chlorinated organics mediated by iron-bearing minerals and provide the theoretical foundation for developing new approaches aimed at addressing chlorinated organic pollution.

关键词： chlorinated organic compounds iron-bearing minerals dechlorination degradation remediation

利用光学方法研究单针射流等离子体的产生和发展机制

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发光学报 2018年第10期39卷 1405-1409页

作者：李永辉甘延标董丽芳北华航天工业学院基础部河北廊坊065000 河北大学物理科学与技术学院河北保定071002

对单针电极射流等离子体产生和发展过程中的光信号进行了研究。首先发现等离子体的长度并不是随外加电压升高而增加,而是和驱动电源的能量在正半周放电脉冲之间的分配有关。通过研究等离子体通道内不同位置的发光信号,发现正半周期第一... 详细信息

对单针电极射流等离子体产生和发展过程中的光信号进行了研究。首先发现等离子体的长度并不是随外加电压升高而增加,而是和驱动电源的能量在正半周放电脉冲之间的分配有关。通过研究等离子体通道内不同位置的发光信号,发现正半周期第一次放电脉冲是在针尖电极处产生,而第二个脉冲是在等离子体通道中部产生,电子激发温度也是在等离子体中部达到最高。通过分析发现,空间电荷产生的附加电场对于等离子体的产生和发展有着重大影响。

关键词：射流等离子体单针电极电子激发温度空间电荷

Dynamic manipulation of multimodal emission in Er^(3+)-activated non-core-shell structure for optical thermometry and information security

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Rare Metals 2024年第4期43卷 1702-1712页

作者： Xuan Liu Zi-Xia Lin Yin-biao Shi Xiao-yan Wang Ming-Ye Ding Xiao-Fei yang College of Science Nanjing Forestry UniversityNanjing210037China Testing Center Yangzhou UniversityYangzhou225009China

Regulating luminescent dynamics of lanthanide-based luminescent materials via external stimuli is of great significance in the fields of optical thermometry and high-level ***,it is still a huge challenge to realize multimodal emissions with tunable color outputs from a single activator in simple structures via smart dynamic control of photon transition ***,we present a mechanistic strategy to achieve multimodal luminescence of Er^(3+)activators with color-switchable outputs in a non-core-shell *** the control of excitation dynamics(λ_(ex)=980,808,1532,377 nm),the population among the intermediate en ergy levels of Er^(3+)and the interaction between Er^(3+)and Yb^(3+)could be precisely modulated through energy transfer and migration processes,leading to the generation of colortunable multimodal luminescence upon diverse excitation modes(non-steady-state,single-/dual-wavelength steady,thermal activation).Inspired by its special luminescent performance,the as-obtained material exhibits great potential in noncontact thermometry,multimodal anticounterfeiting,and high-capacity information encryption by performing a series of proof-of-concept *** findings might provide a conceptual model to modulate the luminescent dynamics in a simple-structured system for the generation of color-adjustable multimodal emissions,which is convenient for the development of advanced luminescent materials toward versatile cuttingedge applications.

关键词： Lanthanide ions Multimodal emission Upconversion Downshifting Anti-counterfeiting Luminescent thermometry

Exploring a new path of green and efficient utilization of sinter return fine to produce composite pellets

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Journal of Iron and Steel Research International 2024年第7期31卷 1610-1622页

作者： yan-biao Chen Wen-guo Liu Hao Guo Jing-song Wang Qing-guo Xue Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China MCC Capital Engineering and Research Incorporation Limited Beijing 100176China

Efficient utilization of sinter return fine is an important measure to reduce cost,increase efficiency,save energy and reduce emission.A new path of green and efficient utilization of return fine was proposed to produce composite *** metallurgical properties of composite pellets under the condition of hydrogen-rich blast furnace were *** experimental results indicate that the coated concentrate was consolidated for the composite pellets through normal Fe_(2)O_(3) *** the surface of core return fine,the liquid phase formed due to its low-melting point,assimilated the adjacent concentrate,and then consolidated with the temperature *** with regular pellets,the com-pressive strength and reduction swelling index of composite pellets were decreased,but the reducibility index and softening-melting properties were *** addition,the reduction degradation index of composite pellets was sig-nificantly higher than that of ***,adding composite pellets was conducive to indirect reduction in blast furnace,reducing fuel ratio and improving production *** to the effect of the roasting system on the metallurgical properties,the roasting temperature and time were determined as 1250℃and 30 min,*** composite pellets can be produced under the traditional pelletizing process.

关键词： Sinter Return fine Composite pellet Roasting system Metallurgical property Hydrogen-rich blast furnace

Research of simulation and experiment on arc characteristics of gas mechanical switch

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High Voltage 2024年第3期9卷 626-635页

作者： Cheng Jiang Lu Qu Zhangqing Yu Zhizheng gan Xin yan Rong Zeng Yulong Huang Shaofu Li Department of Electrical Engineering Tsinghua UniversityBeijingChina School of Information Engineering Southwest University of Science and TechnologyMianyangChina Sichuan Energy Internet Research Institute Tsinghua UniversityChengduChina

An arc is the high-temperature discharge plasma produced in the opening process of mechanical switches,which directly affects the breaking capability of a hybrid DC circuit *** to the physical mechanism of an electric arc,the construction of an arc model for simulation analysis is an important technical means in the electrical *** this study,based on the theory of magneto hydrodynamics(MHD),a gas mechanical switch model of a natural commutation DC circuit breaker with a compound gap is *** arc motion process under different conditions is simulated and *** influence of different initial pressures,different opening speeds,and different striking currents on the arc voltage characteristics is *** results show that the larger the gas pressure,the smaller the arc volume and the higher the arc *** faster the opening speed,the longer the arc and the higher the arc voltage;with the increase of the current,the arc voltage increases rapidly at a low current,while the arc voltage increases slowly at a high current.

关键词： characteristics striking slowly