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PM2.5 over North China based on MODIS AOD and effect of meteorological elements during 2003-2015

Frontiers of Environmental Science & Engineering 2020年第2期14卷 27-40页

作者： Youfang Chen Yimin Zhou Xinyi Zhao College of Urban and Environmental Sciences Peking UniversityBeijing 100871China Key Laboratory for Earth Surface Processes of the Ministry of Education Peking UniversityBeijing 100871China

Over the past 40 years,PM2.5 pollution in North China has become increasingly serious and progressively exposes the densely populated areas to pollutants.However,due to limited ground data,it is challenging to estimate accurate PM2.5 exposure levels,further making it unfavorable for the prediction and prevention of PM2.5 pollutions.This paper therefore uses the mixed effect model to estimate daily PM2.5 concentrations of North China between 2003 and 2015 with ground observation data and MODIS AOD satellite data.The tempo-spatial characteristics of PM2.s and the influence of meteorological elements on PM25 is discussed with EOF and canonical correlation analysis respectively.Results show that overall R2 is 0.36 and the root mean squared predicted error was 30.1μg/m^3 for the model prediction.Our time series analysis showed that,the Taihang Mountains acted as a boundary between the high and low pollution areas in North China;while the northern part of Henan Province,the southern part of Hebei Province and the western part of Shandong Province were the most polluted areas.Although,in 2004,2009 and dates after 2013,PM25 concentrations were relatively low.Meteorological/topography conditions,that include high surface humidity of area in the range of 34°-40°N and 119°-124°E,relatively low boundary layer heights,and southerly and easterly winds from the east and north area were common factors attributed to haze in the most polluted area.Overall,the spatial distribution of increasingly concentrated PM2.5 pollution in North China are consistent with the local emission level,unfavorable meteorological conditions and topographic changes.

关键词： Aerosol optical depth PM2.5 MODIS Mixed effect model Canonical correlation analysis

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The role of organic and inorganic substituents of roxarsone determines its binding behavior and mechanisms onto nano-ferrihydrite colloidal particles

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Journal of Environmental Sciences 2023年第7期129卷 30-44页

作者： Ming Lei Yayuan Huang Yimin Zhou Caleb Oppong Mensah Dongning Wei Bingyu Li College of Resource&Environment Hunan Agricultural UniversityChangsha 410128China Hunan Engineering&Technology Research Center for Irrigation Water Purification Changsha 410128China Key Laboratory of Southern Farmland Pollution Prevention and Control Ministry of AgricultureChangsha 410128China

The retention and fate of Roxarsone(ROX)onto typical reactive soil minerals were crucial for evaluating its potential environmental risk.However,the behavior and molecular-level reaction mechanism of ROX and its substituents with iron(hydr)oxides remains unclear.Herein,the binding behavior of ROX on ferrihydrite(Fh)was investigated through batch experiments and in-situ ATR-FTIR techniques.Our results demonstrated that Fh is an effective geo-sorbent for the retention of ROX.The pseudo-second-order kinetic and the Langmuir model successfully described the sorption process.The driving force for the binding of ROX on Fh was ascribed to the chemical adsorption,and the rate-limiting step is simultaneously dominated by intraparticle and film diffusion.Isotherms results revealed that the sorption of ROX onto Fh appeared in uniformly distributed monolayer adsorption sites.The twodimensional correlation spectroscopy and XPS results implied that the nitro,hydroxyl,and arsenate moiety of ROX molecules have participated in binding ROX onto Fh,signifying that the predominated mechanisms were attributed to the hydrogen bonding and surface complexation.Our results can help to better understand the ROX-mineral interactions at the molecular level and lay the foundation for exploring the degradation,transformation,and remediation technologies of ROX and structural analog pollutants in the environment.

关键词： Ferrihydrite 2D-COS Surface complexation Electrostatic interaction Roxarsone

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A Double-Edged Sword: Russia’s Hybrid Warfare in Syria

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Asian Journal of Middle Eastern and Islamic Studies 2019年第2期13卷 246-261页

作者： Yimin Zhou School of Marxism Xi’an Technological UniversityXi’anChina

Hybrid warfare refers to the use of conventional and unconventional ways and means,by any combination of state and nonstate actors,within the same battle space.Russia has widely employed the concept of hybrid warfare in practice from Ukraine to Syria in the 2010s to advance its interests.The article is presented by solving the following problem:what does Russia’s hybrid warfare in Syria mean to Middle East security issues?The answer to the problem could be obtained by evaluating the theory and practice of Russia’s hybrid warfare.Though the concept of hybrid warfare/hybrid wars was first analysed systematically by Frank Hoffman,an American scholar,in 2007,Russian transformed its methods into a new version to accommodate their specific needs and named it after the Chief of General Staff of the Russian Federation,Witalij Gerasimov.It is necessary to explain the features of Russia’s hybrid warfare theory which helps us assess Russian actions in Syria.And these assessments could show us the efficiency of hybrid warfare.Both the theory and practice of Russia’s hybrid warfare have demonstrated that states may deal with security threats from other state and non-state actors properly by conventional and unconventional ways to keep peace and stability or protect their interests.It may offer us a potential method to eliminate terrorism and extremism in order to save weak or failed states.Yet the aggressiveness of hybrid warfare could also sabotage the vulnerable security structure in the Middle East and cause more conflicts and insurgencies.If so,what should we do to alter the situation?The framework for avoiding the dark side of hybrid warfare is based on international cooperation and assistance to failed states.

关键词： Russia Syria Hybrid Warfare Middle East

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Picture Quality Assessment-Based on Rate Control for Variable Bandwidth Networks

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Tsinghua Science and Technology 2018年第4期23卷 396-405页

作者： Ling Tian Jiaxin Li Yimin Zhou Hongyu Wang School of Computer Science and Engineering University of Electronic Science and Technology of China

The growing popularity of Internet applications and services has rendered high subjective video quality crucial to the user experience. Increasing needs for better video resolution and faster transmission bandwidths present challenges to the goal of achieving balance between video quality and coding cost. In this paper, we propose a Perceptive Variable Bit-Rate Control （PVBRC） framework for the state-of-the-art video coding standard High-Efficiency Video Coding （HEVC）/H.265. PVBRC allocates a bit-rate to a picture while taking a Comprehensive Picture Quality Assessment （CPQA） model and perceptive target bit-rate allocation into consideration. The CPQA model calculates the objective and perceptive quality of both source and reconstructed pictures by referring to the human vision system. The coding bit-rate is then dynamically allocated by the result of the CPQA model according to differences in picture content. In PVBRC, the quantization parameter for current picture encoding is updated by an effective fuzzy logical controller to satisfy the transmission requirements of the Internet of Things. Experimental results show that the proposed PVBRC can achieve average bit savings by 11.49% when compared with constant bit-rate control under the same objective and subjective video quality.

关键词： variable bit rate picture quality assessment rate control networking bandwidth

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A moment-based criterion for determining the number of components in a normal mixture model

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Journal of Systems Engineering and Electronics 2017年第4期28卷 801-809页

作者： Yimin Zhou Liyan Han Dan Wang Libo Yin School of Economics and Management Beihang University Beijing 100191 China School of Instrumentation Science and Opto-electronics Engineering Beihang University Beijing 100191 China School of Finance Central University of Finance and Economics Beijing 100081 China

Determining the number of components is a crucial issue in a mixture model. A moment-based criterion is considered to estimate the number of components arising from a normal mixture model. This criterion is derived from an omnibus statistic involving the skewness and kurtosis of each component. The proposed criterion additionally provides a measurement for the model fit in an absolute sense. The performances of our criterion are satisfactory compared with other classical criteria through Monte-Carlo experiments.

关键词： information criteria Gaussian mixture moment based number of components

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Degradation of iopamidol in the permanganate/sulfite process:Evolution of iodine species and effect on the subsequent formation of disinfection by-products

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Journal of Environmental Sciences 2024年第1期135卷 345-352页

作者： yimin Lin Hongyu Dong Yating Zhu Gongming zhou Junlian Qiao Xiaohong Guan State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Department of Environmental Science School of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China

Permanganate/sulfite(Mn(VII)/S(IV))process is a promising pre-oxidation technology for sequestering the emerging organic contaminants in drinking water treatment plant.Iopamidol(IPM),a representative of iodinated X-ray contrast media,has been widely detected in water sources and has the risk of forming iodinated disinfection byproducts(I-DBPs)in water treatment system.In this study,we investigated the evolution of iodine species during the IPM degradation by the Mn(VII)/S(IV)process and its effect on the subsequent formation of I-DBPs during chlorination at pH 7.0 and 8.0.IPM could be effectively degraded in the Mn(VII)/S(IV)process at environmentally relevant pH(pH 7.0 and 8.0).The results of quenching and competitive oxidation kinetic experiments revealed that SO^(·-)_(4)was the major reactive oxidizing species contributing to the degradation of IPM whereas the contributions of HO·and reactive manganese species were negligible in the Mn(VII)/S(IV)process.I–and IO–3were generated while no HOI was detected during the degradation of IPM in the Mn(VII)/S(IV)process.The effects of IPM oxidation by Mn(VII)/S(IV)on the subsequent formation of chlorinated disinfection by-products(Cl-DBPs)during chlorination were related to the category of Cl-DBPs.The pre-oxidation of IPM by Mn(VII)/S(IV)resulted in the generation of I-DBPs during the disinfection process although no I-DBPs were detected if no pre-oxidation was applied.The finding of this study suggested that attention should be paid to the toxicity of DBPs when water containing iodinated organic contaminants is treated by Mn(VII)/S(IV)process or other pre-oxidation technologies.

关键词： Permanganate/sulfite Iopamidol Sulfate radical Iodinated disinfection byproducts Pre-oxidation

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Spatial-temporal variation features and law of gas concentration in the fully mechanized working face under the condition of intermittent ventilation

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International Journal of Mining Science and Technology 2019年第6期29卷 963-969页

作者： Yinpin Cao yimin Li Zhongning zhou School of Electrical and Power Engineering China University of Mining & Technology

Based on the fluid mechanics and mass transfer theory,a mathematical model of the spatial-temporal variation of gas was derived to avoid the gas accident caused by the main fan stopping ventilation under the condition of intermittent ventilation in the tunnel.According to the actual parameters of the tunnel,a numerical calculation model was established.The spatial-temporal variation of gas concentration in the fully mechanized working face under the condition of intermittent ventilation was calculated by using the commercial package Fluent,and the correctness of the calculated results was verified by the actual monitoring data of the mine.Firstly,the gas concentration was calculated under different wind velocities at driving face in coal tunnel,and the result showed that the gas can be carried effectively by the wind when the wind velocity is about 1.8 m/s.Secondly,the distributions of wind velocity and gas concentration at driving face were studied at 1.8 m/s,and the result showed the gas concentration increased gradually with the distance close to the outlet,but the gas concentration almost kept constant at the height of driving face.Thirdly,the distribution of gas concentration was investigated with time after the ventilation was stopped and restarted,respectively.The gas concentration of test point gradually increased with the increment of downtime,when the downtime was 40 min,the gas concentration of test point 3 reached the maximum value.The gas concentration increased gradually and reached the maximum after10 min of restart,then sharply decreased and kept constant.

关键词： Fully mechanized working face Intermittent ventilation Gas concentration

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A goal-based approach for modeling and simulation of different types of system-of-systems

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Journal of Systems Engineering and Electronics 2023年第3期34卷 627-640页

作者： FENG yimin zhou Chenchu ZOU Qiang LIU Yusheng LYU Jiyuan WU Xinfeng State Key Lab of CAD&CG Zhejiang UniversityHangzhou 310027China Xi’an Aerospace Propulsion Institute Xi’an 710100China China Astronaut Research and Trainning Center Beijing 100094China

A system of systems(SoS)composes a set of independent constituent systems(CSs),where the degree of authority to control the independence of CSs varies,depending on different SoS types.Key researchers describe four SoS types with descending levels of central authority:directed,acknowledged,collaborative and virtual.Although the definitions have been recognized in SoS engineering,what is challenging is the difficulty of translating these definitions into models and simulation environments.Thus,we provide a goal-based method including a mathematical baseline to translate these definitions into more effective agent-based modeling and simulations.First,we construct the theoretical models of CS and SoS.Based on the theoretical models,we analyze the degree of authority influenced by SoS characteristics.Next,we propose a definition of SoS types by quantitatively explaining the degree of authority.Finally,we recognize the differences between acknowledged SoS and collaborative SoS using a migrating waterfowl flock by an agentbased model(ABM)simulation.This paper contributes to the SoS body of knowledge by increasing our understanding of the degree of authority in an SoS,so we may identify suitable SoS types to achieve SoS goals by modeling and simulation.

关键词： simulation systems agent-based modeling systemsof-systems(SoS) systems thinking

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Hollow mesoporous silica nanoparticles as nanocarriers employed in cancer therapy: A review

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Frontiers of Materials Science 2020年第4期14卷 373-386页

作者： Yimin Zhou Qingni XU Chaohua LI Yuqi CHEN Yueli ZHANG Bo LU School of Chemistry Chemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070China

Hollow mesoporous silica nanoparticles(HMSNs)have become an attractive drug carrier because of their unique characteristics including stable physicochemical properties,large specific surface area and facile functionalization,especially made into intelligent drug delivery systems(DDSs)for cancer therapy.HMSNS are employed to transport traditional anti-tumor drugs,which can solve the problems of drugs with instability,poor solubility and lack of recognition,etc.,while significantly improving the anti-tumor effect.And an unexpected good result will be obtained by combining functional molecules and metal species with HMSNs for cancer diagnosis and treatment.Actually,HMSNs-based DDSS have developed relatively mature in recent years.This review briefly describes how to successfully prepare an ordinary HMSNs-based DDS,as well as its degradation,different stimuli-responses,targets and combination therapy.These versatile intelligent nanoparticles show great potential in clinical aspects.

关键词： hollow mesoporous silica nanoparticles intelligent drug delivery system stimuli response targeting drug delivery combination therapy

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Detail control strategies for topology optimization in architectural design and development

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Frontiers of Architectural Research 2022年第2期11卷 340-356页

作者： Xin Yan Dingwen Bao Yufang zhou yimin Xie Tong Cui Center of Architecture Research and Design University of Chinese Academy of SciencesBeijing 100190China School of Architecture and Urban Design RMIT UniversityMelbourne 3001Australia School of Architecture Central Academy of Fine ArtsBeijing 100105China Centre for Innovative Structures and Materials RMIT UniversityMelbourne 3001Australia

With the ability to generate forms with high efficiency and elegant geometry,topology optimization has been increasingly used in architectural and structural designs.However,the conventional topology optimization techniques aim at achieving the structurally most efficient solution without any potential for architects or designers to control the design details.This paper introduces three strategies based on Bi-directional Evolutionary Structural Optimization(BESO)method to artificially pre-design the topological optimized structures.These strategies have been successfully applied in the computational morphogenesis of various structures for solving practical design problems.The results demonstrate that the developed methodology can provide the designer with structurally efficient and topologically different solutions according to their proposed designs with multi-filter radii,multi-volume fractions,and multi-weighting coefficients.This work establishes a general approach to integrating objective topology optimization methods with subjective human design preferences,which has great potential for practical applications in architecture and engineering industry.

关键词： Bi-directional evolutionary structural optimization(BESO) Topology optimization Detail control Diverse design Architectural formfinding

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