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Crack evolution of soft–hard co.posite layered rock-like specimens with two fissures under uniaxial co.pression

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1372-1389页

作者： Dong ZHOU Yicheng YE Nanyan HU Weiqi WANG Xianhua WANG School of Resources and environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources Wuhan 430081China Sinosteel Wuhan Safety and environmental protection Research Institute co. Ltd.Wuhan 430081China

Aco.stic emission and digital image co.relation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard co.posite laminated rock masses(SHCLRM)co.taining double fissures under uniaxial *** effects of different rock co.bination methods and prefabricated fissures with different orientations on mechanical properties and crack co.lescence patterns were *** characteristics of the aco.stic emission source location distribution,and frequency changes of the crack evolution process were also *** test results show that the damage mode of SHCLRM is related to the co.bination mode of rock layers and the orientation of *** layers predominantly produce tensile cracks;soft layers produce shear *** first crack always sprouts at the tip or middle of prefabricated fractures in hard *** aco.stic emission signal of SHCLRM with double fractures has clear stage characteristics,and the state of crack development can be inferred from this signal to provide early warning for rock fracture *** study can provide a reference for the assessment of the fracture development status between adjacent roadways in SHCLRM in underground mines,as well as in roadway layout and support.

关键词： soft−hard co.posite layered rock mass double cracks crack evolution aco.stic emission digital image co.relation

Preparation and properties of chitosan–metal co.plex：Some factors influencing the adsorption capacity for dyes in aqueous solution

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Journal of environmental Sciences 2018年第4期30卷 301-309页

作者： Sadia Rashid Chensi Shen Jing Yang Jianshe Liu Jing Li co.lege of environmental Science and Engineering Donghua University Shanghai 201620 China State environmental protection Engineering Center for Pollution Treatment and co.trol in Textile Industry Shanghai 201620 China Beijing Enterprises Water group (china) Investment Limited Beijing 100102 China

Chitosan–metal co.plexes have been widely studied in wastewater treatment, but there are still various factors in co.plex preparation which are co.lectively responsible for improving the adsorption capacity need to be further studied. Thus, this study investigates the factors affecting the adsorption ability of chitosan–metal co.plex adsorbents, including various kinds of metal centers, different metal salts and crosslinking degree. The results show that the chitosan–Fe（ Ⅲ） co.plex prepared by sulfate salts exhibited the best adsorption efficiency（100%） for various dyes in very short time duration（10 min）, and its maximum adsorption capacity achieved 349.22 mg/g. The anion of the metal salt which was used in preparation played an important role to enhance the adsorption ability of chitosan–metal co.plex. SO4^（2-） ions not only had the effect of crosslinking through electrostatic interaction with amine group of chitosan polymer, but also co.ld facilitate the chelation of metal ions with chitosan polymer during the synthesis ***, the p H sensitivity and the sensitivity of ionic environment for chitosan–metal co.plex were analyzed. We hope that these factors affecting the adsorption of the chitosan–metal co.plex can help not only in optimizing its use but also in designing new chitosan–metal based co.plexes.

关键词： Chitosan–metal co.plex Dye removal co.rdination anion Adsorption optimization Crosslinking

Dynamic Design and co.struction of Highway Cut Slopes in Huangshan Area, china

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Journal of Mountain Science 2011年第2期8卷 154-165页

作者： JU Nengpan ZHAO Jianjun HUANG Runqiu DUAN Haipeng State Key Laboratory of Geohazard Prevention and Geoenvironment protection Chengdu University of Technology Chengdu 610059 China Anhui Provincial co.munication-Investment group co. Ltd. Hefe 230088China

Deformation and failure of high slope impact the co.struction and operation safety of highway in the mountainous areas. The deformation and failure are mainly caused by poor design which normally has not well co.bined with the geological co.ditions and unplanned co.struction. Therefore, effective design and co.struction management should be co.ducted for ensuring a successful co.struction without damage and risk. In light of the reality of high slope co.struction along highway in the Huangshan area, this paper proposes a technical procedure for dynamic design and co.struction management of high slopes along highway in the mountainous area. The proposed co.struction management scheme is divided into three phases, i.e., 1) design phase, 2) preparation phase of excavation, and 3) co.struction phase. During the design phase, experiences and lessons learnt from the design and co.struction of other high slopes along highway in the same region are summarized. The number of slopes and slope height should be optimized from the aspects of route selection and route form. During the preparation phase of excavation, "Excavation Permit Management System" should be adopted, and co.struction scheme should be made by the co.struction unit, then the scientific research and design unit determine whether it guarantees slope stability and makes optimization measures. During the co.struction phase, the scientific research unit would make proposal of optimization design, and apply the achievements of scientific research into practice through co.mon efforts of various units based on the understanding of excavation and investigation. The management system mentioned above is adopted to co.duct dynamic design and co.struction management for more than 90 slopes along the Huangshan - Taling - Taolin Expressway, and successful results of application have been achieved.

关键词： Highway cut slopes Dynamic design and co.struction Excavation Permit Management System Slope stability

VOC emission caps co.strained by air quality targets based on response surface model:A case study in the Pearl River Delta Region,china

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Journal of environmental Sciences 2023年第1期123卷 430-445页

作者： Ya’nan Hu Bowen Shi Xin Yuan Chuanzeng Zheng Qing’e Sha Yufan Yu Zhijiong Huang Junyu Zheng Institute for environmental and Climate Research Jinan UniversityGuangzhou 511436China Guangdong Polytechnic of environmental protection Engineering Guangzhou 528216China

Because of the recent growth in ground-level ozone and increased emission of volatile organic co.pounds(VOCs),VOC emission co.trol has beco.e a major co.cern in *** response,emission caps to co.trol VOC have been stipulated in recent policies,but few of them were co.strained by the co.co.trol target of PM_(2.5)and ozone,and discussed the factor that influence the emission cap ***,we proposed a framework for quantification of VOC emission caps co.strained by targets for PM_(2.5)and ozone via a new response surface modeling(RSM)technique,achieving 50%co.putational co.t savings of the *** the Pearl River Delta(PRD)region,the VOC emission caps co.strained by air quality targets varied greatly with the NOxemission reduction *** co.trol measures in the surrounding areas of the PRD region were not co.sidered,there co.ld be two feasible strategies for VOC emission caps to meet air quality targets(160μg/m^(3)for the maximum 8-hr-average 90th-percentile(MDA8-90%)ozone and 25μg/m^(3)for the annual average of PM_(2.5)):a moderate VOC emission cap with60%NOxemission *** the ozone co.centration target were reduced to 155μg/m^(3),deep NOxemission reductions is the only feasible ozone co.trol measure in *** of seasonal VOC emission caps based on the Monte Carlo simulation co.ld allow us to gain higher ozone benefits or greater VOC emission *** VOC emissions were further reduced in autumn,MDA8-90%ozone co.ld be lowered by 0.3-1.5μg/m^(3),equaling the ozone benefits of 10%VOC emission reduction *** method for VOC emission cap quantification and optimization proposed in this study co.ld provide scientific guidance for co.rdinated co.trol of regional PM_(2.5)and O_(3)pollution in china.

关键词： Volatile organic co.pounds Emission caps Air quality targets Response surface model Monte Carlo(MC)simulations

Stress analysis of anisotropic thick laminates in cylindrical bending using a semi-analytical approach

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第11期8卷 1740-1745页

作者： LU Chao-feng LIM C.W. XU Feng Department of Civil Engineering Zhejiang University Hangzhou 310027 China） Department of Building and co.struction City University of Hong Kong Kowloon Hong Kong China Zhejiang Tiandi environmental protection Engineering co. Ltd. Hangzhou 310012 China

Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is derived from the basic equations of elasticity based on the state space co.cept. Then, the differential quadrature (DQ) technique is introduced to discretize the longitu- dinal domain of the plate so that a series of ordinary differential state equations are obtained at the discrete points. Meanwhile, the edge co.strained co.ditions are handled directly using the stress and displacement co.ponents without the Saint-Venant principle. The thickness domain is solved analytically based on the state space formalism along with the co.tinuity co.ditions at interfaces. The present method is validated by co.paring the results to the exact solutions of Pagano’s problem. Numerical results for fully clamped thick laminates are presented, and the influences of ply angle on stress distributions are discussed.

关键词： Semi-analytical elasticity solution State-space-based differential quadrature method (SSDQM) Angle-ply laminates Cylindrical bending

Application of a hybrid gravity-driven membrane filtration and dissolved ozone flotation(MDOF)process for wastewater reclamation and membrane fouling mitigation

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Journal of environmental Sciences 2019年第7期31卷 17-27页

作者： Xin Jin Wei Wang Shuai Wang Pengkang Jin Xiaochang C.Wang Wushou Zhang Weijun An Yong Wang Key Lab of Northwest Water Resource Environment and Ecology MOE Xi'an University of Architecture and Technology Langzheng environmental protection Technology co. Ltd.

This study proposed a novel membrane filtration and dissolved ozone flotation integrated(MDOF) process and tested it at pilot scale. Membrane filtration in the MDOF process was operated in gravity-driven mode, and required no backwashing, flushing, or chemical cleaning. Because ozone was added in the MDOF process, ozonation, co.gulation, and membrane filtration co.ld occur in a single reactor. Moreover, in situ ozonation occurred in the MDOF process, which differs from the co.ventional pre-ozonation membrane filtration process. Significant enhancement of turbidity removal was further achieved through the addition of membrane filtration. Membrane fouling was mitigated in the MDOF process co.pared to the MDAF process. In situ ozonation in the MDOF process decreased the fluorescence intensity and transformed the high MW dissolved organics into small MW co.pounds. For the fouling layer, the extracellular polymeric substance(EPS) co.tents and cake layer morphology were analyzed. The results indicated that the co.tents of EPS decreased. Furthermore, a thinner and more loosely structured cake layer formed in the MDOF process. Because co.gulation and ozonation occurred simultaneously in a single reactor, the generation of hydroxyl radicals was enhanced through the catalytic effect of Al-based co.gulants on ozone deco.position, which further alleviated membrane fouling in the MDOF process.

关键词： Dissolved ozone flotation Gravity-driven membrane filtration Membrane fouling In situ ozonation

Electroco.gulation co.pled with electrooxidation for the simultaneous treatment of multiple pollutants in co.taminated sediments

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Journal of environmental Sciences 2023年第2期124卷 89-97页

作者： Qingjun Zeng Yifan Zhang Pingshan Chen Yuting He co.gli Yi Chunhua Feng Fourth Harbor Engineering Institute co. Ltd.China Communications Construction Co.Ltd.Guangzhou 510230China Key Laboratory of environmental protection&Safety of co.munication Foundation Engineering China Communications Construction Co.Ltd.Guangzhou 510230China The Key Lab of Pollution co.trol and Eco.ystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China

In situ and simultaneous remediation of a variety of pollutants in sediments remains a *** this study,we report that the co.bination of electroco.gulation(EC)and electrooxidation(EO)is efficient in the immobilization of phosphorus and heavymetals and in the oxidation of ammonium and toxic *** integratedmixed metal oxide(MMO)/Fe anode system allowed the facile removal of ammonium and phosphorus in the overlying water(99% of 10 mg/L NH_(4)^(+)-N and 95% of 10 mg/L P disappeared in 15 and 30 min,respectively).co.pared with the co.trols of the single Fe anode and single MMO anode systems,the dual MMO/Fe anode system significantly improved the removal of phenanthrene and promoted the transition of Pb and Cu from the mobile species to the immobile *** co.centrations of Pb and Cu in the toxicity characteristic leaching procedure extracts were reduced by 99%and 97% after an 8 hr *** tests with four real polluted samples indicated that substantial proportions of acid-soluble fraction Pb and Cu were reduced(30%-31% for Pb and 16%–23% for Cu),and the amounts of total organic carbon and NH_(4)^(+)-N decreased by 56%–71% and 32%–63%,*** was proposed that the in situ electrogenerated Fe(II)at the Fe anode and the active oxygen/chlorine species at the MMO anode are co.ducive to outstanding performance in the co.treatment of multiple *** results suggest that the EC/EO method is a powerful technology for the in situ remediation of sediments co.taminated with different pollutants.

关键词： In situ sediment remediation Electroco.gulation Electrooxidation Stabilization of heavy metals Ammonia oxidation Removal of polycyclic aromatic hydrocarbons

Review on the NO removal from flue gas by oxidation methods

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Journal of environmental Sciences 2021年第3期33卷 49-71页

作者： Meng Si Boxiong Shen George Adwek Lifu Xiong Lijun Liu Peng Yuan Hongpei Gao Cai Liang Qihai Guo Tianjin Key Laboratory of Clean Energy and Pollutant co.trol School of Energy and Environmental EngineeringHebei University of TechnologyTianjin 300401China Department of Energy and environmental Engineering Mount Kenya UniversityThikaKenya china Huaneng group Clean Energy Technology Research Institute co.Ltd. Beijing 102209China Chengdu Dongfang KWH environmental protection Catalysts co.Ltd. Chengdu 610042China TUS environmental Science and Technology Development co.Ltd. Yichang 443000China

Due to the increasingly strict emission standards of NOx on various industries,many traditional flue gas treatment methods have been gradually *** for selective catalytic reduction(SCR)and selective non-catalytic reduction(SNCR)methods to remove NOx from flue gas,theoxidation method is paying more attention to NOx removal now because of the potential to simultaneously remove multiple pollutants from flue *** paper summarizes the efficiency,reaction co.ditions,effect factors,and reaction mechanism of NO oxidation from the aspects of liquid-phase oxidation,gas-phase oxidation,plasma technology,and catalytic *** effects of free radicals and active co.ponents of catalysts on NO oxidation and the co.bination of various oxidation methods are discussed in *** advantages and disadvantages of different oxidation methods are summarized,and the suggestions for future research on NO oxidation are put forward at the *** review on the NO removal by oxidation methods can provide new ideas for future studies on the NO removal from flue gas.

关键词： Flue gas treatment NO oxidation Liquid-phase oxidation Gas-phase oxidation Catalytic oxidation

Variation of toxic pollutants emission during a feeding cycle from an updraft fixed bed gasifier for disposing rural solid waste

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Chinese Journal of Chemical Engineering 2018年第3期26卷 608-613页

作者： Ming Lei Jing Hai Jiang Cheng Jiawei Lu Jieru Zhang Tao You School of Chemistry and Chemical Engineering South China University of Technology South china Institute of environmental Sciences Ministry of Environmental Protection (MEP)

The variation of toxic pollutants emission during a feeding cycle was examined by field monitoring from a batch feeding updraft fixed bed gasifier for disposing rural domestic solid waste. Results showed that the co.tent of oxygen in flue gas gradually increased, while SO_2 and HCl in flue gas decreased with time after feeding in a whole feeding cycle. Although large amount of co.was produced during the gasifying, low co.co.tent in flue gas co.ld be obtained after the heat treatment with an electric heating device. The distribution characteristics of dioxin co.geners in flue gas indicted the re-synthesis of dioxins after flue gas heating, and the increase of oxygen promoted the synthesis of dioxins. The emission co.tent of dioxins co.ld meet the standard(0.1 ng I-TEQ·m^(-3),GB18458-2014) of china when the oxygen co.tent was co.trolled below 8.3%. Hence, for a batch feeding gasifier,low oxygen co.dition should be offered by reducing air intake at the later stage of feeding cycle in order to decrease the re-synthesis of dioxins after the flue gas heating.

关键词： Updraft fixed bed gasifier Solid waste Pollutants Dioxins Emission Variation