检索结果-南通市图书馆

Production of high-energy neutron beam from deuteron breakup

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第7期33卷 125-132页

作者： Ren-sheng Wang Li Ou zhi-Gang Xiao School of Radiation Medicine and Protection Medical College of Soochow UniversitySuzhou215123China Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions Suzhou215123China College of Physics and Technology Guangxi Key Laboratory of Nuclear Physics and TechnologyGuangxi Normal UniversityGuilin541004China Department of Physics Tsinghua UniversityBeijing100084China

The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero *** experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by *** on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was *** of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is *** coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying *** enables the application of a well-defined energy neutron beam in an event-by-event scheme.

关键词： Deuteron breakup Monochromatic neutron High energy Quantum molecular dynamics

Fe(Ⅱ)-mediated transformation of schwertmannite associated with calcium from acid mine drainage treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第4期126卷 612-620页

作者： Cong Fan Chuling Guo Wei Chen Guining Lu Yu Shen zhi dang National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business UniversityChongqing 400067China School of Environment and Energy South China University of TechnologyGuangzhou 510006China The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou 510006China Chongqing Key Laboratory of Environmental Materials and Remediation Technologies Chongqing University of Arts and SciencesChongqing 402160China

Schwertmannite is an important Fe(Ⅲ)-oxyhydroxysulfate in acid mine drainage (AMD) polluted areas and its stability depends on surrounding environmental factors and previously bound *** treatment and neutralization of AMD normally involve the use of lime,which leads to the discharge of abundant Ca in the mining *** an environmental disturbance brings up an important and less considered problem of how the reductive transformation of schwertmannite associated with coexisting Ca ***,the Fe(Ⅱ)-mediated transformation of Ca-adsorbed schwertmannite and subsequent Ca repartitioning behaviors were *** showed that adsorbed Ca had a weak inhibitory effect on Fe(Ⅱ)-mediated schwertmannite *** of SO_(4)2-and SEM images both indicated that transformation rates of schwertmannite decreased under the influence of adsorbed *** patterns indicated that adsorbed Ca altered schwertmannite transformation pathways and product compositions upon treatment with 0.4 mmol/L Fe(Ⅱ).The end products of Sch notably contained both goethite and lepidocrocite;however,transformation products of SchCa only contained goethite all *** 33.5%of the surface adsorbed-Ca was released into solution within 6 hr after Fe(Ⅱ) *** Ca behaved in a“first release and then im-mobilization”manner,which indicated dissolution and secondary mineralization drove Ca migration during the Fe(Ⅱ)-mediated transformation of *** Ca blocked the surface sites for subsequent Fe(Ⅱ) adsorption,limited the Fe(Ⅱ)-Fe(Ⅲ) ETAE,and decreased the transformation *** work sheds light on the complex geochemical behavior of schwertmannite under the influences of environmental perturbations in AMD environments.

关键词： Acid mine drainage Schwertmannite Calcium Fe(II) Transformation

COPOLYMERIZATION OF ETHYLENE AND 1-HEXENE WITH TiCl_4/MgCl_2 CATALYSTS MODIFIED BY 2,6-DIISOPROPYLPHENOL

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第1期31卷 110-121页

作者： sheng-jie Xia zhi-sheng Fu Xiao-yan Liu 范志强 MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University

A supported TiCl4/MgCl2 catalyst without internal electron donor （O-cat） was prepared firstly. Then it was modified by 2,6-diisopropylphenol to make a novel modified catalyst （M-cat）. These two catalysts were used to catalyze ethylene/l-hexene copolymerization and l-hexene homopolymerization. The influence of cocatalyst and hydrogen on the catalytic behavior of these two catalysts was investigated. In ethylene/l-hexene copolymerization, the introduction of 2,6- iPr2C6H3O- groups did not deactivate the supported TiCl4/MgCl2 catalyst. Although the 1-hexene incorporation in ethylene/1- hexene copolymer prepared by M-cat was lower than that prepared by O-cat, the composition distribution of the former was narrower than that of the latter. Methylaluminoxane （MAO） was a more effective activator for M-cat than triisobutyl- aluminium （TIBA）. MAO led to higher yield and more uniform chain structure. In 1-hexene homopolymerization, the presence of 2,6-ipr2C6H3O- groups lowered the propagation rate constants. Two types of active centers with a chemically bonded 2,6-iprzCaH3O- group were proposed to explain the observed phenomena in M-cat.

关键词： Supported Ziegler-Natta catalyst 2,6-Diisopropylphenol Ethylene copolymerization Active center distribution.

Remediation of soil and groundwater contaminated with organic chemicals using stabilized nanoparticles: Lessons from the past two decades

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2020年第5期14卷 83-102页

作者： Zhengqing Cai Xiao Zhao Jun Duan Dongye Zhao zhi dang Zhang Lin National Engineering Lab for High-concentration Refractory Organic Wastewater East China University of Science and TechnologyShanghai 200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China College of Water Resources&Civil Engineering China Agricultural UniversityBeijing 100083China Environmental Engineering Program Department of Civil EngineeringAuburn UniversityAuburnAL 36849USA School of Environment and Energy South China University of TechnologyGuangzhou 510006China

Due to improved soil deliverability and high reactivity,stabilized nanoparticles have been studied for nearly two decades for in situ remediation of soil and groundwater contaminated with organic *** large amounts of bench-and field-scale experimental data have demonstrated the potential of the innovative technology,extensive research results have also unveiled various merits and constraints associated different soil characteristics,types of nanoparticles and particle stabilization ***,this work aims to critically overview the fundamental principles on particle stabilization,and the evolution and some recent developments of stabilized nanoparticles for degradation of organic contaminants in soil and *** specific objectives are to:1)overview fundamental mechanisms in nanoparticle stabilization;2)summarize key applications of stabilized nanoparticles for in situ remediation of soil and groundwater contaminated by legacy and emerging organic chemicals;3)update the latest knowledge on the transport and fate of stabilized nanoparticles;4)examine the merits and constraints of stabilized nanoparticles in environmental remediation applications;and 5)identify the knowledge gaps and furore research needs pertaining to stabilized nanoparticles for remediation of contaminated soil and *** instructions of this invited special issue,this review is focused on contributions from our group(one of the pioneers in the subject field),which,however,is supplemented by important relevant works by *** knowledge gained is expected to further advance the science and technology in the environmental applications of stabilized nanoparticles.

关键词： Stabilized nanoparticle In-situ remediation Organic contaminant Soil remediation Groundwater Fate and transport

Co-metabolic and biochar-promoted biodegradation of mixed PAHs by highly efficient microbial consortium QY1

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第9期33卷 65-76页

作者： Min Li Hua Yin Minghan Zhu Yuanyuan Yu Guining Lu zhi dang Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters School of Environment and EnergySouth China University of TechnologyGuangdong 510006China Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyGuangdong 525000China

Polycyclic aromatic hydrocarbons(PAHs), typical representatives of the persistent organic pollutants(POPs), have become ubiquitous in the *** this study, a novel microbial consortium QY1 that performed outstanding PAHs-degrading capacity has been *** degradation characteristics of single and mixed PAHs treated with QY1 were studied, and the effect of biochar on biodegradation of mixed PAHs and the potential of biochar in PAHs-heavy metal combined pollution bioremediation were also *** showed that, in single substrate system, QY1 degraded 94.5% of 500 mg/L phenanthrene(PHE) and 17.8% of 10 mg/L pyrene(PYR) after 7 days, while in PHE-PYR mixture system, the biodegradation efficiencies of PHE(500 mg/L) and PYR(10 mg/L) reached 94.0%and 96.2%, respectively, since PHE served as co-metabolic substrate to have significantly improved PYR ***, with the cooperation of biochar, the biodegradations of PHE and PYR were greatly ***, biochar could reduce the adverse impact of heavy metals(Cd^(2+), Cu^(2+), Cr_(2)O_(7)^(2-)) on PYR biodegradation *** sequencing analysis revealed that Methylobacterium, Burkholderia and Stenotrophomonas were the dominant genera of QY1 in almost all treatments, indicating that these genera might play key roles in PAHs ***, this study provided new insights into the efficient bioremediation of PAHs-contaminated site.

关键词： Polycyclic aromatic hydrocarbons Microbial consortium Co-metabolism Biochar Heavy metals Microbial community

Remediation performance and mechanisms of Cu and Cd contaminated water and soil using Mn/Al-layered double oxide-loaded biochar

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第3期125卷 593-602页

作者： Pengcheng Lin Hang Liu Hua Yin Minghan Zhu Haoyu Luo zhi dang School of Environment and Energy South China University of TechnologyGuangzhou 510006China Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters Guangzhou 510006China Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling Guangzhou 510006China

The combined pollution of heavy metals is ubiquitous ***/Al-layered double oxide-loaded crab shells biochar (LDO/BC) was prepared,so as to remediate the combined pollution of Cd and Cu in soil and *** pristine and used LDO/BC were characterized and the results revealed that the layered double oxide was successfully loaded on crab shells biochar (BC) and metal element Ca in crab shells was beneficial to the formation of more regular layered and flake *** maximal adsorption capacity (Qm) of LDO/BC for aqueous Cu^(2+)and Cd^(2+)was 66.23 and 73.47 mg/g,***/BC and BC were used to remediate e-waste-contaminated soil for the first time and exhibited highly efficient *** extraction amount of Cu and Cd in the contaminated soil by diethylene triamine penta-acetic acid (DTPA) after treating with 5% LDO/BC was significantly reduced from 819.84 to 205.95 mg/kg (with passivation rate 74.8%) and 8.46 to 4.16 mg/kg(with passivation rate 50.8%),respectively,inferring that the bioavailability of heavy metals declined *** experimental result also suggested that after remediation by LDO/BC the exchangeable and weak acid soluble Cu and Cd in soil translated to reducible,residual and oxidizable fraction which are more stable ***,complexation and ion exchange were proposed as the possible mechanisms for Cd and Cu *** general,these experiment results indicate that LDO/BC can be a potentially effective reagent for remediation of heavy metal contaminated water and soil.

关键词： Mn/Al-layered double oxide Biochar Cd and Cu combined pollution Adsorption Soil remediation

Performance Analysis of the Effects of Microgrooved Surface on A Marine Current Turbine with Underwater Mooring Platform

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2022年第5期36卷 755-766页

作者： dang zhi-gao MAO Zhao-yong SONG Bao-wei YANG Guang-yong School of New Energy Nanjing University of Science and TechnologyJiangyin 214443China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory for Unmanned Underwater Vehicle Northwestern Polytechnical UniversityXi’an 710072China Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an 710072China

Marine current turbine(MCT),which is designed for the power supply of underwater mooring platform(UMP),is investigated in this *** reduce its flow noise,the microgrooved surface is applied at the suction surface of the turbine *** analyses of the effects of the UMP on MCT with microgrooved surface in different working conditions are *** transient turbulent flow field is obtained by incompressible large eddy simulation(LES),and then the Ffowcs Williams and Hawkings(FW-H)acoustic analogy is adopted to forecast the flow noise generated from the pressure fluctuations and loadings of the UMP shell and MCT blade *** numerical methods are first validated with experimental data and good agreements are ***,the influence of several key parameters on the performance of the MCT is then systematically studied,including interval distance,angle of pitch and angle of *** each case,the hydrodynamic parameters(thrust coefficient,torque coefficient and power coefficient),the vortical structures behind the model and the overall sound pressure level(OASPL)directionality are ***,the noise reduction effect of the microgrooved surface is also *** present investigation could provide an overall understanding for the performance of MCT combined with UMP.

关键词： marine current turbine underwater mooring platform microgrooved surface large eddy simulation flow noise

Land cooperatives as an approach of suburban space construction： Under the reform of Chinese land transfer market

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2016年第4期5卷 425-432页

作者： sheng dang Dachang Yuan Weiyuan Kong School of Architecture Tianjin University Tianjin 300072 China

In China, the urban-rural dual structure of land market has resulted in urban sprawl caused by industrial diffusion. Urban sprawl disintegrated agricultural communities in suburbs, thereby increasing the unemployment rate among farmers who lost their lands. To address this problem, the Chinese government proposed a reform program to analyze the monopoly of the government in the land market and guarantee the property rights of farmers. This study analyzed the connection between land market mechanism and suburban space formation. Results concluded that the current land transfer system caused industrial urban sprawl, and the reform program may promote the urban sprawl of population. Two typical models of rural land development were studied. A model called land cooperatives based on land pooling joint stock system was proposed to build a compact and sustainable suburban space.

关键词： Land institution Suburban space Urban sprawl Land cooperatives

Impact of habitat diversification on arthropod communities： A study in the fields of Chinese cabbage, Brassica chinensis

在线全文

学校读者我要写书评

暂无评论

Insect Science 2007年第3期14卷 241-249页

作者： HONG-JIAO CAI zhi-sheng LI MIN-sheng YOU Institute of Applied Ecology Research Centre for Biodiversity and Eco-Safety Fujian Agriculture and Forestry University Fuzhou China

Field trials were carried out from June to August in 2004 at Wuyishan （Wuyi Mountains）, Fujian province, China, to determine the effects of habitat diversification on arthropod communities. Two Chinese cabbage, Brassica chinensis, field 1 （F1） and field 2 （F2） surrounded by diverse vegetable cultivars were selected, while a monoculture of Chinese cabbage served as the control field （CK）. The results showed that：（i） when comparing insect abundance of each order between different habitats, significantly higher numbers of lepidopterous insects （39.76% from the each order） and lower densities of Hymenoptera （19.82%） were found in CK than in F1 and F2; （ii） compared with CK, F1 and F2 had a lower percentage of species richness and an abundance of herbivorous insects, but increased richness, abundance and biodiversity of predatory insects; （iii） no differences were observed in neutral insects＇ guild between different fields; and （iv） the dominant species for each guild depends on the habitat types and sampling dates. This study suggests that intercropping could conceivably be used in these habitats to increase the population of natural predators, thus achieving desirable and ecologically friendly results in vegetable fields.

关键词： arthropod community community composition community architecture diversity habitat