检索结果-南通市图书馆

Hydrous cerium oxides coated glass fiber for efficient and long-lasting arsenic removal from drinking water

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2021年第2期10卷 247-257页

作者： Ronghui Li Weiyi Yang shuang gao Jianku Shang Qi Li School of Gemology and Material Technology Hebei GEO UniversityShijiazhuang050031China Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu610031China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

A novel arsenic adsorbent with hydrous cerium oxides coated on glass fiber cloth(HCO/GFC)was *** HCO/GFC adsorbents were rolled into a cartridge for arsenic removal *** to the large pores between the glass fibers,the arsenic polluted water can flow through *** arsenic removal performance was evaluated by testing the equilibrium adsorption isotherm,adsorption kinetics,and packed-bed *** pH effects on arsenic removal were *** test results show that HCO/GFC filter has high As(Ⅴ)and As(Ⅲ)removal capacity even at low equilibrium *** more toxic As(Ⅲ)in water can be easily removed within a wide range of solution p H without *** contaminated ground-water from Yangzong Lake(China)was used in the column *** typical breakthrough conditions(the empty bed contact time,EBCT=2 min),arsenic researched breakthrough at over 24,000 bed volumes(World Health Organization(WHO)suggested that the maximum contaminant level(MCL)for arsenic in drinking water is 10 mg/L).The Ce content in the treated water was lower than 5 ppb during the column test,which showed that cerium did not leach from the HCO/GFC material into the treated *** relationship between dosage of adsorbents and the adsorption kinetic model was also clarified,which suggested that the pseudo second order model could fit the kinetic experimental data better when the adsorbent loading was relatively low,and the pseudo first order model could fit the kinetic experimental data better when the adsorbent loading amount was relatively high.

关键词： hydrous cerium oxide(HCO) glass fiber cloth(GFC) column test adsorption kinetics adsorption mechanism

Influence of C/Ti stoichiometry in TiC_x on the grain refinement efficiency of Al–Ti–C master alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第7期33卷 616-622页

作者： Huabing Yang Tong gao Haichao Wang Jinfeng Nie Xiangfa Liu Nano Structural Materials Center School of Materials Science and Engineering Nanjing University of Science and Technology Nanjing 210094 China

TiC_x contained Al-Ti-C is a kind of grain refiner for Al alloys. In this work, the influence of C/Ti stoichiometry, i.e. the x value in TiC_x on grain refinement efficiency was investigated. TiC_x particles have been obtained in five Al-5Ti-m C（m = 0.1, 0.5, 0.8, 1, 1.25） master alloys and the x values were measured to be0.72, 0.75, 0.79, 0.81 and 0.8, respectively. It was found that the refinement performance of the master alloys had a close relationship with the x value of TiC_x . The Al-5Ti-m C alloy with lower-x TiC_x shows better refinement efficiency and anti-fading capability. It is supposed that TiC_x particles with lower x are more preferred to release Ti atoms during nucleating process and have a better Ti-absorbing *** contributes to the Ti-rich zone formation at TiC_x /melt interface, thus enhancing the refinement and anti-fading capability.

关键词： Al alloys Nucleation Grain refinement TiC_x

Formation mechanism,experimental method,and property characterization of graindisplacing methane hydrates in marine sediment:A review

在线全文

学校读者我要写书评

暂无评论

China Geology 2022年第2期5卷 345-354页

作者： Yong-chao Zhang Le-le Liu gao-wei Hu Qing-tao Bu Cheng-feng Li Zheng-cai Zhang Jian-ye Sun Chang-ling Liu The Key Laboratory of Gas Hydrate Qingdao Institute of Marine GeologyChina Geological SurveyMinistry of Natural ResourcesQingdao 266237China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and TechnologyQingdao 266237China

Grain-displacing hydrate deposits exist at many marine sites,which constitute an important part of methane hydrate resources *** to the difficulties in acquiring field data and synthesizing experimental samples,the formation and property characterization of grain-displacing hydrate remains less understood and characterized than the pore-filling hydrate in current *** study reviews the formation mechanisms of grain-displacing hydrate from the perspective of geological accumulation and microscale sedimentary *** experimental methods of synthesizing grain-displacing hydrate in the laboratory and the current knowledge on the property of grain-displacing hydrate sediment are also *** in current theories and suggestions for future study are *** work is hoped to provide valuable insights for the research into the hydrate accumulation,geophysics,and hydrate exploitation targeted at the grain-displacing hydrate in the marine sediments.

关键词： Methane hydrates Formation mechanism Grain-displacing hydrate Pore-filling hydrate Synthesis method Sedimentary property Oil and gas exploration engineering NGHs exploration trial engineering

Adaptive Control of the Structural Balance for a Class of Complex Dynamical Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2020年第3期33卷 725-742页

作者： gao Zilin WANG Yinhe PENG Yi LIU Lizhi CHEN Haoguang Key Laboratory of Intelligent Information Processing and Control of Chongqing Municipal Institutions of Higher Education Chongqing Three Gorges UniversityChongqing 404100China School of Computer Science and Engineering Chongqing Three Gorges UniversityChongqing 404100China School of Automation Guangdong University of TechnologyGuangzhou 510006China School of Computer Science Zhongshan Institute of Electronic Science and Technology University of ChinaZhongshan 528402China

In social networks,the structural balance is a state of a group of individuals(nodes)with established mutual relationships(connection relationships)between *** is easy to see that a social network can be described by a complex dynamical network model composed of the nodes subsystem(NS)and the connection relationships subsystem(CS),where the two subsystems are usually coupled with each *** implies that the dynamic changes of nodes'states may cause the structural balance in ***,few papers have discussed the relationship between the structural balance and the specific dynamic changes of the nodes'*** paper proposes a model of complex dynamical networks,and mainly focuses on the dynamic changes of states in NS which can lead to the structural balance in *** is proved that if each state in NS is doing a specific dynamic motion via the controller with the parameter adaptive law,then the CS can track a given structural balance matrix via the effective coupling and the structural balance can be *** a result can be regarded as an explanation of the relationship between the structural balance and the specific dynamic changes of the nodes'***,the simulations verify the effectiveness of the proposed method.

关键词： Complex dynamical networks connection relationships effective coupling structural balance

Computational Study on the Boundary Layer Suction Effects in the Supersonic Compressor Flow with a Bowed Blade

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第2期31卷 511-528页

作者： CAO Zhiyuan SONG Cheng gao Xi ZHANG Xiang LIU Bo School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China

Flow control methodologies have been widely used to eliminating flow separation and increasing the blade load in axial *** at revealing the flow mechanism of coupled bowed blading and boundary layer suction in a supersonic compressor cascade,a cascade with a diffusion coefficient of 0.62 is numerically *** of all,according to the available experimental data,the numerical method was validated;then,different bowed blading effects on flow field in detail were investigated;at last,based on the flow physics of purely bowed blading,the positively bowed blade was coupled with boundary layer suction on blade suction surface,whereas the negatively bowed blade was coupled with endwall *** coupled control method,influence mechanism on flow field,especially on the shock structure was revealed,and different aspect ratios of coupled control method were investigated as *** showed that the coupled positively bowed blading and suction surface suction can eliminate the flow separation *** with that of baseline supersonic cascade,the total pressure loss coefficient of the coupled scheme was reduced by 37.4%at *** mid-span,the shock moved downstream and the single shock was separated to a dual-shock structure since the positively bowed blading reduced the static pressure of *** coupled negatively bowed blading and endwall suction also effectively enhanced the performance of cascade by removing the corner separation,with the loss coefficient reduced by as much as 41.9%.However,the suction coefficient of optimal coupled negatively bowed blading scheme reached 10.5%,which is too high for practical *** coupled control,the 3 D shock structure became“C”shaped distribution along spanwise because of the difference in influence mechanism of negatively bowed blading on different spanwise *** to the opposite influence effect of positively and negatively bowed blading,the shock structure in the two different sc

关键词： supersonic compressor cascade bowed blading boundary layer suction shock aspect ratio

Degradation modeling of degradable copolymers for biomimetic scaffolds

在线全文

学校读者我要写书评

暂无评论

Friction 2020年第3期8卷 594-603页

作者： taohong ZHANG Yue gao Lingling ZHU Qingfeng ZENG Ming ZHOU Computer Department School of Computer&Communication EngineeringUniversity of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Knowledge Engineering for Materials Science Beijing 100083China State Key Laboratory of Tribology School of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Biomimetic scaffolds provide a suitable growth environment for tissue engineering and demonstrate good potential for application in biomedical ***-sized copolymerized biomimetic scaffolds degrade differently,and the degradation rate is affected by the copolymerization *** study of the degradation property is the foundational research necessary for realizing individualized biomimetic scaffold *** degradation performance of polyesters with different copolymerization ratios has been widely reported;however,the modeling of this performance has been rarely *** this research,the degradation of copolymers was studied with multi-scale modeling,in which the copolymers were dispersed in a cellular manner,the chain break time was simulated,and the chain selection was based on the Monte Carlo(MC)*** probability model of the copolymer's chain break position was established as a//roulette,/model,whose probability values were estimated by the calculation of the potential energy difference at different chain break positions by molecular dynamics that determined the position of chain shear,thereby fully realizing the simulation of the chain micro-break *** diffusion of the oligomers was then calculated using the macro diffusion equation,and the degradation process of the copolymer was simulated by three-scale coupling *** calculation results were in good agreement with the experimental data,demonstrating the effectiveness of the proposed method.

关键词： copolymer for biomimetic scaffolds copolymerization ratio degradation modeling multi-scale model probability model for chain break location

Oxide formation mechanism of a corrosion-resistant CZ1 zirconium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第16期147卷 6-15页

作者： Jing Hu Weitong Lin Qingyang Lv Changyuan gao Jun Tan China Nuclear Power Technology Research Institute Shenzhen 518000GuangdongChina

Tailoring microstructure and microchemistry by altering elemental compositions and thermomechanical treatment parameters enables superior corrosion performance in zirconium alloys for nuclear ***,our understanding of the relationship between various defects and the corrosion process remains limited in the newly developed zirconium *** we report the oxide formation mechanism of a CZ1 zirconium alloy with corrosion resistance surpassing many other zirconium alloy systems,such as Zircaloy-4 and Zr-1Nb-1Sn *** experiments of CZ1 alloy and Zr1Nb-1Sn model alloy were performed in 360°C water for up to 820 *** quantitively determined oxide phases by transmission Kikuchi diffraction(TKD)and examined lateral cracks,nano-porosity,and second-phase particles in oxide scales by transmission electron microscopy(TEM).Compared to the Zr-1Nb-1Sn model alloy,CZ1 alloy with lower Nb and Sn concentrations has shown smaller and lower-density lateral cracks but slightly larger oxide grains,reducing the diffusion route for oxidating *** analytical scanning and transmission electron microscopy,we demonstrate that due to the lower content of Sn(∼0.9 wt.%),there is less tetragonal ZrO_(2) phase formed in the oxide,and the level of tetragonal to the monoclinic phase transition is *** the Nb content(0.1 wt.%–0.3 wt.%)is lower than the solid solution limit of Nb in Zr,by introducing minor elements such as Fe,Cr,and Cu,there are still a reasonable number of second-phase particles to relieve the high stress associated with the metal-to-oxide *** mechanisms have substantially changed the density and distribution of lateral cracks in the oxide,thus reducing the corrosion rate of zirconium alloys.

关键词： Zirconium alloy Corrosion Oxide microstructure Lateral crack Tetragonal phase Nano-porosity

Accurate Analysis of Connectivity and Resilience for a Class of Wireless Sensor Networks

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

Chinese Journal of Electronics 2020年第2期29卷 208-219页

作者： PANG Shanqi HU Xianchao gao Qiang LI Yongmei XIA Yifan College of Mathematics and Information Science Henan Normal University Henan Engineering Laboratory for Big Data Statistical Analysis and Optimal Control Henan Normal University

Increasing attention is being devoted to network security with the extensive application of wireless sensor networks in various fields. Connectivity and resilience are the crucial metrics of network *** establish precise formulas for obtaining the resilience of a Key predistribution scheme(KPS) obtained from an Orthogonal array(OA). We study the connectivity and resilience of the Broadcast-enhanced key predistribution scheme(BEKPS) based on OAs and improve the existing methods. We also present precise formulas for evaluating the resilience of these schemes based on any number of partitions, completely solving the problem regarding the resilience of this type of BEKPS. We obtain precise formulas for ensuring the connectivity of two partitions under the condition that each pair of trees from different partitions intersects at exactly one node. We present a general approximate formula for evaluating the connectivity of more than two partitions, providing a positive solution to the open problem in Kendall et al.’s paper in ACM Transactions on Sensor Networks(Vol.11,No.1, 2014). Thus, we can conclude that for this type of BEKPS, connectivity increases, whereas resilience remains unchanged as the number of partitions increases. A comparison of the obtained results and the previously reported results reveals the superior performance of the proposed BEKPSs.

关键词： Wireless sensor network Key predistribution scheme Broadcast-enhanced key predistribution scheme Orthogonal array

Numerical Investigation on Characteristics of Supercritical CO_(2)Heat Transfer in Vertical Circular Tubes with Circumferentially Half-Side Heating

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第5期33卷 1744-1756页

作者： ZHANG Yan ZHANG Xinyi YAN Chenshuai WU Wenhua gao Erman School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The design of heat exchangers in the advanced supercritical power conversion system cannot be separated from the study of heat transfer ***-side heating mode is often encountered for solar receiver and supercritical ***,the characteristics of supercritical CO_(2)(sCO_(2))convection heat transfer in vertical tubes with circumferentially half-side heating was numerically investigated through the SST k-ωturbulent model which matches well with the experimental ***,heat transfer between sCO_(2)upflow and downflow was *** to film boiling heat transfer at subcritical pressure,numerical results were processed according to the supercritical pseudo-phase transition hypothesis,with liquid-like phase in the tube core region and vapor-like film in the region near the heated tube *** structure of two layers was demarcated by pseudo-critical temperature T_(pc).Therefore,sCO_(2)heat transfer was assessed according to double thermal resistances caused by vapor-like film near the wall and core liquid-like *** findings suggest that wall temperature for upflow is higher than that for downflow,which is attributed to larger thermal resistance in the fluid domain for upflow than that for *** difference guarantees the excellent heat transfer performance for downflow than *** is also further concluded that the formation of vapor-like film near the wall due to pseudo-phase transition plays a key role in dominating wall temperature and inducing heat transfer deterioration in half-side heating *** present contribution is significant to the design of supercritical heat exchanger under half-side heating mode.

关键词： supercritical CO_(2) pseudo-phase transition half-side heating thermal resistance flow direction