检索结果-南通市图书馆

Progress in preparation of AlN-reinforced magnesium matrix composites:A review

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 1-10页

作者： Lu Chen shu-lin Lü Di-jia Zhao Wei Guo jian-yu Li shu-sen Wu State Key Lab of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

As a ceramic material,AlN has very good thermophysical and mechanical *** addition,AlN is an effective refining agent for Mg alloys because it has a lattice constant similar to that of ***,AlN is an ideal reinforcement for magnesium matrix composites(MMCs),and is attracting increasing *** review addresses the development of preparation technologies for AlN-reinforced Mg matrix *** mainstream preparation techniques include stir casting,melt infiltration,powder metallurgy,and in-situ *** addition,the advantages and disadvantages of these techniques are analyzed in depth,and it is pointed out that the next direction for the preparation of high-performance AlN-reinforced MMCs is less aluminization and multiple technologies integration.

关键词： AlN MMCs preparation thermophysical property mechanical property

The Complete Classification of Graphs whose Second Largest Eigenvalue of the Eccentricity Matrix is Less Than 1

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1741-1766页

作者： jian Feng WANG Xing Yu LEI shu Chao LI Zoran STANIC School of Mathematics and Statistics Shandong University of TechnologyZibo255049P.R.China Faculty of Mathematics and Statistics Central China Normal UniversityWuhan430079P.R.China Faculty of Mathematics University of BelgradeStudentski trg 1611000BelgradeSerbia

The eccentricity matrix of a graph is obtained from the distance matrix by keeping the entries that are largest in their row or column,and replacing the remaining entries by *** matrix can be interpreted as an opposite to the adjacency matrix,which is on the contrary obtained from the distance matrix by keeping only the entries equal to *** the paper,we determine graphs having the second largest eigenvalue of eccentricity matrix less than 1.

关键词： Eccentricity matrix eigenvalue diameter principal submatrix forbidden subgraph

Experimental Study on Engineering Behavior of Solidified Soil for Scour Repair and Protection

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 625-635页

作者： WU Xiao-ni LI Ru-yu shu jian TANG Chao CHEN Jin-jian WANG Hui-li jianG Hai-li WANG Xiao State Key Laboratory of Ocean Engineering Department of Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Road and Bridge Group Co. Ltd.Shanghai 200433China Shanghai Engineering Research Center of Urban Infrastructure Renewal Shanghai 200032China jiangsu Kunze Technology Co. Ltd.Nanjing 210000China

A new scour countermeasure using solidified slurry for offshore foundation has been proposed *** solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies *** the pumping operation and solidification,the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-scour performance related retention rate in solidification and bearing capacity related strength property after *** this study,a series of laboratory tests are conducted to investigate the effects of mix proportion(initial water content and binder content)on the flow value,rheological properties,density,retention rate of solidified slurry and unconfined compressive strength(UCS).The results reveal that the flow value increases with the water content and decreases with the binder *** the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and viscosity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified *** rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is contrary to anti-scour *** unconfined compressive strength after solidification reduces as the water content increases and binder content decreases.A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference.

关键词： scour repair and protection solidified soil pumpability strength flow properties anti-scour performance

Highly dispersed MgInCe-mixed metal oxides catalyzed direct carbonylation of glycerol and CO_(2)into glycerol carbonate

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第8期72卷 153-163页

作者： Xufang Chen Xin shu Yanru Zhu jian Zhang Zhigang Chai Hongyan Song Zhe An Jing He State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou 324000China

Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so *** direct carbonylation from glycerol with CO_(2)is considered a promising route,but still tough work due to the thermodynamic stability and the kinetic inertness of CO_(2).In this work,highlyselective direct carbonylation of glycerol and CO_(2)into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides(MgInCe-MMO),which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides(MgInCe-LDHs).By precisely modulating the surface basic-acidic properties and the oxygen vacancies,an efficient carbonylation of glycerol with CO_(2)has been achieved with a selectivity of up to>99%to glycerol *** investigation into the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.

关键词： Catalytic reaction engineering Glycerol carbonate Direct carbonylation from glycerol Carbon dioxide Mixed metal oxides Synergistic catalysis

Aero-Hydro-Elastic-Servo Modeling and Dynamic Response Analysis of A Monopile Offshore Wind Turbine Under Different Operating Scenarios

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第3期38卷 379-393页

作者： XIE shuang-yi GAO jian LI Yong-ran jianG shu-xin ZHANG Cheng-lin HE Jiao College of Mechanical Engineering Chongqing University of TechnologyChongqing 400044China Beijing Institute of Precision Mechatronics and Controls Beijing 100076China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China Fishery Machinery and Instrument Research Institute Chinese Academy of Fishery SciencesShanghai 200092China School of Mechanical and Power Engineering Chongqing University of Science&TechnologyChongqing 401331China

This paper constructs a coupled aero-hydro-elastic-servo simulation framework for a monopile offshore wind turbine(OWT).In this framework,a detailed multi-body dynamics model of the monopile OWT including the gearbox,blades,tower and other components(nacelle,hub,bedplate,etc.)has been explicitly *** effects of pile−soil interaction,controller and operational conditions on the turbine dynamic responses are studied systematically in time domain and frequency *** results show that(1)a comprehensive drivetrain model has the capability to provide a more precise representation of the complex dynamic characteristics exhibited by drivetrain components,which can be used as the basis for further study on the dynamic characteristics of the drivetrain.(2)The pile−soil interaction can influence the wind turbine dynamic responses,particularly under the parked condition.(3)The effect of the pile−soil interaction on tower responses is more significant than that on blade responses.(4)The use of the controller can substantially affect the rotor characteristics,which in turn influences the turbine dynamic responses.(5)The tower and blade displacements under the operational condition are much larger than those under the parked *** model and methodology presented in this study demonstrate potential for examining complex dynamic behaviors of the monopile *** ensure accuracy and precision,it is imperative to construct a detailed model of the wind turbine system,while also taking into account simulation efficiency.

关键词： offshore wind turbine(OWT) pile−soil interaction dynamic response parked condition operating condition

Translocation of a fish spike from the pharynx to the thyroid gland:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第7期12卷 1365-1370页

作者： Deng Li Wan-Ting Zeng jian-Guo jiang Ji-chuan Chen Department of Otolaryngology Head and Neck Surgery Army Medical Center of PLAChongqing 400042China

BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)***,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid *** and timely management can help reduce complications,especially in elderly *** SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the *** the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her ***,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a *** If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the *** avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its *** the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.

关键词： Fish spike Thyroid Pharynx Foreign body migration Case report

Hot Compression Behavior and Tensile Property of a Novel Ni-Co-Based Superalloy Prepared by Electron Beam Smelting Layered Solidification Technology

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

Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 283-292页

作者： Yong-Chao Gai Rui Zhang chuan-Yong Cui Zi-jian Zhou Yi Tan Yi-Zhou Zhou Xiao-Feng Sun Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The hot compression behavior and tensile strength after compression of a new Ni-Co-based superalloy produced using electron beam smelting layered(EBSL)solidification technology were *** compression tests were performed at temperatures of 1120℃and 1150℃,with strain rates of 1 s^(-1) and 0.01 s^(-1),reaching a true strain of *** strength was evaluated at room *** results revealed that this EBSL technology accelerates dynamic recrystallization(DRX),without compromising the strength of alloy.A significant correlation between the volume fraction of DRX and the strain rate was observed,with higher fractions at lower strain rates,leading to higher tensile ***,at the same strain rate,the specimens compressed at 1120℃exhibited higher tensile strength due to undissolvedγ′*** solution and aging heat treatment,the alloy maintained high tensile *** results suggested that the EBSL Ni-Co-based superalloy offers excellent prospects for practical applications.

关键词： Ni-Co-based superalloy Hot deformation Electron beam smelting Tensile strength

Visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO_(2)

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 Chemical Letters 2024年第7期35卷 281-284页

作者： Tian-Yu Gao Xiao-Yan Mo shu-Rong Zhang Yuan-Xu jiang shu-Ping Luo jian-Heng Ye Da-Gang Yu Key Laboratory of Green Chemistry&Technology of Ministry of Education College of ChemistrySichuan UniversityChengdu 610064China State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology Zhejiang University of TechnologyHangzhou 310014China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

Herein, we report the first visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO_(2)to synthesize hydroxy acid derivatives. A variety of valuable β-, γ-, δ-, ε–hydroxy acid derivatives are obtained in moderate to high yields under mild conditions. This protocol shows noteworthy functionalgroup compatibility, high chemo-and regioselectivities under transition-metal-free conditions with an inexpensive organo-dye as photosensitizer. Mechanistic studies indicate that the benzylic carbanion is generated as an intermediate via the sequential single electron transfer(SSET) process.

关键词： Carbon dioxide Epoxides Visible-light photoredox catalysis Hydroxy acid Sequential single electron transfer

Recent advances in vacancy engineering for reliable lithiumsulfur batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 455-477页

作者： Wen-Dong Liu Xiao Tang Jun-An Feng Chao-Yue Zhang Hao Liu chuan Shi Xiao-Xian Zhao jian-Jun Song College of Physics School of Chemistry and Chemical EngineeringQingdao UniversityQingdao266071China Faculty of Science Centre for Clean Energy TechnologySchool of Mathematical and Physical SciencesUniversity of Technology SydneySydneyNSW2007Australia Department of Chemistry College of ScienceHebei Agricultural UniversityBaoding071001China

The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application ***,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of *** response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of ***,vacancy engineering has gained the attention of researchers due to its unique electronic *** review aims to analyze the application of vacancy engineering in ***,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been ***,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,*** latest applications of vacancy engineering in LSBs are also summarized in this ***,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.

关键词： Lithium-sulfur batteries(LSBs) Defects Vacancy engineering Electronic structure shuttle effect