检索结果-南通市图书馆

Journal of Environmental Sciences 2008年第7期20卷 820-826页

作者： liu chen WU Guangxia MU Huanzhen Research Center for Eco-Environmental Sciences Chinese Academic of SciencesBeijing 100085China

In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were *** results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and *** runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...

关键词： application copolymer a copolymer of lignin starch acrylamide and acrylic acid (LSAA) non-point source pollution (NPS) surface runoff

Achieving strength-ductility synergy in a non-equiatomic Cr_(10)Co_(30)Fe_(30)Ni_(30)high-entropy alloy with heterogeneous grain structures

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第8期41卷 2864-2876页

作者： chen-Liang Chu Wei-Ping chen Jun-chen liu Qiang chen Zhi-Qiang Fu Guangdong Key Laboratory for Advanced Metallic Materials Processing South China University of TechnologyGuangzhou510641China Southwest Technology and Engineering Research Institute Chongqing400039China

Cold rolling and post-deformation annealing(PDA)heat treatments were used to produce heterogeneous grain structures(HGS)in a single-phase face-centered cubic(fcc)Cr_(10)Co_(30)Fe_(30)Ni_(30)high-entropy alloy(HEA).The microstructural evolution and microstructure-property relationship of the HEA were systematically studied under different *** could be achieved in PDA-treated samples at 875℃for 20 s and at 900℃for 20 s(PDA-900-20 s).PDA-900-20 s sample exhibits the most excellent combination of strength and ductility,showing a tensile yield strength of~590 MPa,an ultimate strength of~706 MPa and a total elongation of~23.9%.Additionally,compared with the homogenized counterpart exhibiting homogenous grains,PDA-900-20 s sample displays a notable increment of~413%in yield strength and simultaneously maintains a good *** dominated strengthening mechanisms in PDA-900-20 s sample are grain-boundary strengthening and heterogeneous deformation-induced(HDI)strengthening,whereas the good ductility is mainly resulted from the HDI ***,the present study provides an effective and simple pathway to overcome the strength-ductility tradeoff of typical fcc HEAs through heterogeneous microstructure.

关键词： High-entropy alloy Heterogeneous grain structures Hetero-deformation-induced hardening Mechanical properties Strengthening mechanism

Slow-gathering areas of rivers, lakes, and reservoirs: Definition, estimation, and restoration

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2023年第1期16卷 113-116页

作者： Ming chen Ya-fei Li chen liu Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China

Recently,humans have been facing serious water pollution problems that aggravate water resources *** 2025,two-thirds of the world's population is likely to live in countries with moderate or severe water shortages(Azizullah et al.,2011).Rivers,lakes,and reservoirs are important sources of ***,there are approximately 8.5 million rivers(Linke et al.,2019),21.15 million natural lakes,and 1.427 million large reservoirs(Messager et al.,2016).Many of them have been contaminated due to urbanization,industrialization,and agricultural *** particular,all rivers,lakes,and reservoirs have their own slow-gathering areas(SGAs)where the input contaminants are easily stopped and deposited due to their non-open morphologies and low flow speeds.

关键词： reservoirs gathering estimation

Preparation of indium tin oxide targets with a high density and single phase structure by normal pressure sintering process

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

Rare Metals 2011年第2期30卷 126-130页

作者： liu chen liu Jiaxiang WANG Yue College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China

The present work mainly describes the technology for preparing indium-tin oxide （ITO） targets by cold isostatic pressing （CIP） and normal pressure sintering process. ITO powders were produced by chemical co-precipitation and shaped into an ITO green compact with a relative density of 60% by CIP under 300 MPa. Then, an ITO target with a relative density larger than 99.6% was obtained by sintering this green compact at 1550℃ for 8 h. The effects of forming pressure, sintering temperature and sintering time on the density of the target were inves- tigated. Also, a discussion was made on the sintering atmosphere.

关键词： thin films indium tin oxide (ITO) isostatic pressing sintering relative density microstructure

Unexpanded nonlinear electromagnetic gyrokinetic equations for magnetized plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2020年第10期22卷 1-4页

作者： liu chen Fulvio ZONCA Haotian chen Institute for Fusion Theory and Simulation and Department of Physics Zhejiang UniversityHangzhou 310027People’s Republic of China Department of Physics and Astronomy University of CaliforniaIrvineCA 92697United States of America ENEA Fusion and Nuclear Safety DepartmentC.R.FrascatiVia E.Fermi 4500044 Frascati(Roma)Italy Institute of Space Science and Technology Nanchang UniversityNanchang 330031.People's Republic of China

Nonlinear electromagnetic gyrokinetic equations have been constructed without expanding the field variables into background and finite but small-amplitude fluctuating components. At the long-wavelength limit, these unexpanded nonlinear gyrokinetic equations recover the wellknown drift-kinetic equations. At the expanded limit, they recover the usual nonlinear gyrokinetic equations. These equations can therefore be applied to long-term simulations covering from microscopic to macroscopic spatial scales.

关键词： gyrokinetic theory plasma turbulence nonlinear phenomena

Performance of overlapped shield tunneling through an integrated physical model tests,numerical simulations and real-time field monitoring

在线全文

学校读者我要写书评

暂无评论

Underground Space 2017年第1期2卷 45-59页

作者： Junlong Yang chen liu Qiushi chen Xiongyao Xie Key Laboratory of Geotechnical and Underground of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China Glenn Department of Civil Engineering Clemson UniversityClemsonSC 29634USA

In this work,deformations and internal forces of an existing tunnel subjected to a closely overlapped shield tunneling are monitored and analyzed using a series of physical model experiments and numerical *** of different excavation sequences and speeds are explicitly considered in the *** results of the physical model experiments show that the bottom-up tunneling procedure is better than the top-down tunneling *** incurred deformations and internal forces of the existing tunnel increase with the excavation speed and the range of influence areas also increase *** construction process control,real-time monitoring of the power tunnel is *** monitoring processes feature full automation,adjustable frequency,real-time monitor and dynamic feedback,which are used to guide the construction to achieve micro-disturbance *** accordance with the situation of crossing construction,a numerical study on the performance of power tunnel is carried *** control measures are given for the undercrossing construction,which helps to accomplish the desired result and meet protection requirements of the existing tunnel ***,monitoring data and numerical results are compared,and the displacement and joint fracture change models in the power tunnel subject to the overlapped shield tunnel construction are analyzed.

关键词： Overlapped tunnel Automatic monitoring Micro-disturbance control

Anomalous chiral transports and spin polarization in heavy-ion collisions

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

Nuclear Science and Techniques 2020年第6期31卷 30-51页

作者： Yu-chen liu Xu-Guang Huang Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China

Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical *** strong EM field and vorticity can induce intriguing macroscopic quantum phenomena such as chiral magnetic,chiral separation,chiral electric separation,and chiral vortical effects as well as the spin polarization of *** phenomena provide us with experimentally feasible means to study the nontrivial topological sector of quantum chromodynamics,the possible parity violation of strong interaction at high temperature,and the subatomic spintronics of quark–gluon *** studies,both in theory and in experiments,are strongly connected with other subfields of physics such as condensed matter physics,astrophysics,and cold atomic physics,and thus form an emerging interdisciplinary research *** give an introduction to the aforementioned phenomena induced by the EM field and vorticity and an overview of the current status of experimental research in heavy-ion *** also briefly discuss spin hydrodynamics as well as chiral and spin kinetic theories.

关键词： Heavy-ion collision Chiral magnetic effect Spin polarization Quark–gluon plasma

Co-strengthening contribution of δ′and T_1 precipitates in Al-Li alloys 2090 and 2090+Ce

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2006年第3期25卷 197-201页

作者： ZHAO Zhilong liu Lin chen Zheng School of Mechatronic Engineering Northwestern Polytechnic University Xi＇an 710072 China

The microstructure of dislocation in two kinds of ahiminum-lithium alloys 2090 and 2090 ＋ Ce was observed by means of TEM technology. The contributions of δ＇ and T1 precipitates to strength were separately calculated by using the results of quantitative metallography and analysis of micro-deformation behavior; the co-strengthening effect of δ＇ and T1 precipitates was studied. The results show that the adding relationship of co-strengthening of δ＇ and T1 is in accordance with q = 1.4 form at the near peak-aged condition, i.e., △τ^1.4δ = △τ^1.4δ＋ △τ^1.4T1, but the adding relationship is approximately a linear relation （q = 1） at the under-aged condition and becomes the parabola form when over-aged （q = 2）. The adding relationship of co-strengthening contribution of δ＇ and T1 is obviously dependent on aging time.

关键词： metal materials aluminum-lithium alloy precipitates strengthening

Impact of Spatial Scale and Building Exposure Distribution on Earthquake Insurance Rates:A Case Study in Tangshan,China

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2023年第1期14卷 64-78页

作者： Pan Zhang Xiaojun Li chen liu Institute of Geophysics China Earthquake AdministrationBeijing100081China Key Laboratory of Urban Security and Disaster Engineering of China Ministry of Education Beijing University of TechnologyBeijing100124China Institute of Disaster Prevention Sanhe065201China China Re Catastrophe Risk Management Company Ltd. Beijing100033China

In order to examine the effect of spatial scale and building exposure distribution on the pure rate of earthquake catastrophe insurance,this study described three modules for rate determination,put forward the general assumptions and principles for calculating the pure insurance rate,and introduced three types of building distribution and their *** Tangshan City of Hebei Province in China as an example,we analyzed the pure rate of regional earthquake insurance in terms of spatial scale and building exposure distribution by using the method of control *** results show that for districts(or counties)with large differences in seismic risk,the risk areas can be further divided to apply differential *** areas with a diverse distribution of potential earthquake source areas and large differences in building density,there is a risk of overestimating or underestimating the pure rate of earthquake insurance when buildings are distributed evenly or partially *** violates the break-even principle of rate *** study also provides a reference for earthquake catastrophe insurance companies to choose the spatial scale and the detailed level of exposure distribution in rate determination.

关键词： Catastrophe insurance Earthquake exposure Premium rate Spatial scale Tangshan China

Recent progress in thermal/environmental barrier coatings and their corrosion resistance

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2020年第5期39卷 498-512页

作者： Hong-Fei chen Chi Zhang Yu-chen liu Peng Song Wen-Xian Li Guang Yang Bin liu School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Institute of Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

Thermal/environmental barrier coatings(T/EBCs)play important roles in jet and/or gas turbine engines to protect the Ni-based superalloys and/or ceramic matrix composite substrates from the high-temperature airflow *** efforts have been contributed to searching for enhanced T/EBC materials to improve the efficiency of the engines,which is the key of improving thrust-to-weight ratio and energy *** practical candidates,rare earth-contained materials,are widely used for T/EBCs in gas turbines due to their excellent properties such as low thermal conductivity,high melting point,hightemperature strength and durability as exhibited in yttriastabilized zirconia,pyrochlore oxides and rare earth *** addition to the intrinsic properties,the microstructures obtained by different synthesis processes and the service performances,as well as the underlying failure mechanism,are also significant to this specific ***,the main challenges for T/EBCs developments are T/EBC materials selection with balanced properties and their anti-corrosion performances at higher operating *** this review,we summarized the progress in their fabrication techniques and mechanical/thermal properties of typically rare earth-contained T/EBCs,together with their anti-corrosion performance under the condition of molten salts or oxides(such as Na2SO4,V2O5and NaVO3),calcium–magnesium–alumina–silicate(CMAS)and high-temperature water vapor.

关键词： Thermal/environmental barrier coatings Yttria-stabilized zirconia Rare earth zirconates Rare earth silicates Corrosion resistance