检索结果-南通市图书馆

grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： Hong-bin Dai jian Miao jia-xin lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIg)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIg arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIg arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIg arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

Machine Learning Security Defense Algorithms Based on Metadata Correlation Features

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2391-2418页

作者： Ruchun jia jianwei Zhang Yi lin College of Computer Science Sichuan UniversityChengdu610065China

With the popularization of the Internet and the development of technology,cyber threats are increasing day by *** such as malware,hacking,and data breaches have had a serious impact on *** network security environment in the era of big data presents the characteristics of large amounts of data,high diversity,and high real-time *** security defense methods and tools have been unable to cope with the complex and changing network security *** paper proposes a machine-learning security defense algorithm based on metadata association *** control over unauthorized users through privacy,integrity,and *** user model is established and the mapping between the user model and the metadata of the data source is *** analyzing the user model and its corresponding mapping relationship,the query of the user model can be decomposed into the query of various heterogeneous data sources,and the integration of heterogeneous data sources based on the metadata association characteristics can be *** and classify customer information,automatically identify and perceive sensitive data,build a behavior audit and analysis platform,analyze user behavior trajectories,and complete the construction of a machine learning customer information security defense *** experimental results show that when the data volume is 5×103 bit,the data storage integrity of the proposed method is 92%.The data accuracy is 98%,and the success rate of data intrusion is only 2.6%.It can be concluded that the data storage method in this paper is safe,the data accuracy is always at a high level,and the data disaster recovery performance is *** method can effectively resist data intrusion and has high air traffic control *** can not only detect all viruses in user data storage,but also realize integrated virus processing,and further optimize the security defense effect of user big data.

关键词： Data-oriented architecture metadata correlation features machine learning security defense data source integration

Experimental,Numerical,and Analytical Studies on the Bending of Mechanically lined Pipe

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第2期38卷 221-232页

作者： WEI Wen-bin YUAN lin ZHOU jia-sheng LIU Zheng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China School of Mechanical Engineering Tianjin UniversityTianjin 300072China

Mechanically lined pipe(MLP)is often used for offshore oil and gas transport because of its low cost and corrosion *** installation and operation,the pipe may undergo severe bending deformation,which causes the liner to separate from the outer pipe and buckles,affecting the stability of the whole *** this paper,the buckling response of MLP subjected to bending is investigated to clarify its bending characteristics by employing both experiments,numerical simulation,as theoretical *** types of MLPs were manufactured with gB 45 carbon steel(SLP)and Al 6061(ALP)used as the outer pipe material,*** hydraulic expansion and bending experiments of small-scale MLPs are *** addition to the ovalized shape of the cross-section for the SLP specimens,the copper liner was found to wrinkle on the compressive *** contrast,the liner of ALP remains intact without developing any wrinkling and collapse *** addition,a dedicated numerical framework and theoretical models were also *** was found both the manufacturing and bending responses of the MLP can be well reproduced,and the predicted maximum moment and critical curvatures are in good agreement with the experimental results.

关键词： lined pipe bending nonlinear ring theory buckling plasticity

Ultra-high NA graphene oxide flat lens on a fiber facet with near diffraction-limited focusing

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第7期12卷 1457-1463页

作者： XIAOKE CHEN lin MA ZUYUAN HE gUIYUAN CAO HAN lin BAOHUA jia State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong UniversityShanghai 200240China Nanophotonics Research Center Shenzhen Key Laboratory of Micro-Scale Optical Information TechnologyShenzhen UniversityShenzhen 518060China School of Science RMIT UniversityMelbourne VIC 3000Australia The Australian Research Council(ARC)Industrial Transformation Training Centre in Surface Engineering for Advanced Materials(SEAM) RMIT UniversityMelbourne VIC 3000Australia

The realization of a high numerical aperture(NA) fiber lens is critical for achieving high imaging resolution in endoscopes, enabling subwavelength operation in optical tweezers and high efficiency coupling between optical fibers and photonic chips. However, it remains challenging with conventional design and fabrication. Here we propose an ultrathin(400 nm) graphene oxide(gO) film lens fabricated in situ on a standard single-mode fiber facet using the femtosecond laser direct writing technique. An extremely high NA of 0.89 is achieved with a near diffraction-limited focal spot(FWHM = 0.68λ), which is verified theoretically and experimentally. The diameter of the fabricated fiber gO lens is as small as 12 μm with no beam expansion structure. The proposed fiber gO lens is promising for applications such as super-resolution imaging, compact optical tweezers, medical endoscopes,and on-chip integration.

关键词： fiber high oxide

Interconnection of cellular autophagy and endosomal vesicle trafficking and its role in hepatitis B virus replication and release

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2024年第1期39卷 24-30页

作者： jia Li Yong lin Xueyu Wang Mengji Lu Institute for Virology University Hospital EssenUniversity of Duisburg-EssenEssen45122Germany Key Laboratory of Molecular Biology of Infectious Diseases(Chinese Ministry of Education) Chongqing Medical UniversityChongqing400016China The Key Laboratory for Diagnosis and Treatment of Infectious Diseases The First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou310000China

Hepatitis B virus(HBV)produces and releases various particle types,including complete virions,subviral particles with envelope proteins,and naked *** studies demonstrate that HBV exploits distinct intracellular membrane trafficking pathways,including the endosomal vesicle trafficking and autophagy pathway,to assemble and release viral and subviral ***,we summarize the findings about the distinct roles of autophagy and endosomal membrane trafficking and the interaction of both pathways in HBV replication,assembly,and release.

关键词： Amphisome Autophagy Endosomal vesicle Hepatitis B virus(HBV)

The configuration of Au^(δ+)-ZrO_(2)^(δ−)species induced activation enhances electrocatalytic CO_(2)to formate conversion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6006-6015页

作者： Yongjian jia Yadi Zhang Mengque lin Yangyang Cheng Yanjie Xu National Engineering Research Center for Technology and Equipment of Environmental Deposition Lanzhou Jiaotong UniversityLanzhou 730070China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong UniversityLanzhou 730070China School of Environmental Engineering and Chemistry Luoyang Institute of Science and TechnologyLuoyang 471023China

Electrochemical CO_(2)conversion into value-added chemicals is a promising technology to solve the greenhouse effect and recycle chemical ***,the electrochemical CO_(2)reduction reaction(e-CO_(2)RR)is seriously compromised by weak CO_(2)adsorption and a rough CO_(2)activation process based on the chemical inertness of the CO_(2)molecule and the formed fragile metal–C/O *** this paper,we designed and fabricated Au particles embedded in ZrO_(2).The configuration of Au particles being of positive charge and ZrO_(2)with negative charge is induced and generated by metal–support interactions(MSIs).As a result,Au/ZrO_(2)@C presents a big difference in the CO_(2)conversion compared with the known work,affording a formate yield of 112.5μmol·cm^(−2)·h^(−1)at−1.1 V *** hydrogen electrode(RHE),and a max formate Faradaic efficiency of up to 94.1%at−0.9 V *** superior performance was attributed to the activated Au–ZrO_(2)interface to form the Au^(δ+)*** insitu Fourier transform infrared(FTIR)spectroscopy and theoretical calculations show that the MSIs configuration can be inclined to the*OCO intermediate generation on Au^(δ+)species activating CO_(2)molecules and then accelerate the formation of the*OCHO intermediate in e-CO_(2)RR,thereby favoring the CO_(2)conversion to formate.

关键词： electrochemical CO_(2)reduction reaction(e-CO_(2)RR) Au_(δ+)species formic acid *OCHO intermediate metal-support interactions

Paleogene integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第4期67卷 1290-1325页

作者： jia LIU Ai SONg lin DINg Tao SU Zhekun ZHOU CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Institute of Paleontology Yunnan UniversityKunming 650500China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern *** the Qinghai-Tibetan Plateau and its surrounding regions,the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny,reorganization of Asian climates,and evolution of *** to limitations in research conditions and understanding,there are still many controversies regarding stratigraphic divisions in the Qinghai-Tibetan Plateau and its surrounding *** recent years,extensive studies on sedimentary petrology,magnetostratigraphy,and isotope dating have been conducted in the *** fossils have been discovered and reported,contributing to a more systematic understanding of *** studies have laid a solid foundation for the comprehensive investigation of the stratigraphy,biotas and paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding regions during the *** this paper,we integrate recent research on fossils,isotopic dating,magnetostratigraphy,and geochemistry to refine the stratigraphic divisions and correlation framework of different tectonic units in the region,building upon previous *** the Second Tibetan Plateau Scientific Expedition and Research,the knowledge of Paleogene floras has gradually *** paper discusses the biostratigraphic significance of extinct and newly appeared taxa based on the latest dating results of these plant *** new understanding of fossil species such as the“Eucalyptus”and Arecaceae establishes connections between the Paleogene flora of the Qinghai-Tibetan region and the biotas of gondwana,specifically Oceania and South *** evolutionary history of key taxa near the Yarlung Zangbo suture zone indicates that the collision between the Indian and Eurasian plates occurred approximately 65-54 *** reconstructions,based o

关键词： Qinghai-Tibetan Plateau Fossils Biostratigraphy Paleoenvironment Paleogeography Paleogene

The principle and amelioration of lithium plating in fast-charging lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第10期97卷 453-459,I0009页

作者： Yi Yang Xia-lin Zhong Lei Xu Zhuo-lin Yang Chong Yan jia-Qi Huang School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Yangtze River Delta graduate School of Beijing Institute of Technology Jiaxing 314003ZhejiangChina

Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of ***,we investigate the Li plating behavior in porous electrodes under the restricted transport of Li^(+).Based on the theoretical model,it can be concluded that the Li plating on the anodeseparator interface(ASI)is thermodynamically feasible and kinetically ***,the prior deposition of metal Li on the ASI rather than the anode-current collector interface(ACI)is verified *** order to facilitate the transfer of Li^(+)among the electrode and improve the utilization of active materials without Li plating,a bilayer asymmetric anode composed of graphite and hard carbon(gH)is *** and simulation results suggest that the gH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li *** work provides new insights into the behavior of Li plating and the rational design of electrode structure.

关键词： graphite Hard carbon Fast charging Lithium plating Lithium-ion batteries

Curcumin Interferes with TgF-β1-Induced Fibrosis in NRK-49F Cells by Reversing ADAMTS18 gene Methylation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第7期30卷 600-607页

作者： XU Ben ZHANg jia-en YE lin YUAN Chang-wei Department of Urology Peking University First Hospital and Institute of UrologyPeking UniversityNational Urological Cancer CenterBeijing100034China

Objective To explore the molecular mechanism by which curcumin affects renal interstitial fibrosis(RIF)progression by regulating ADAM metallopeptidase with thrombospondin type 1 motif 18(ADAMTS18)*** NRK-49F cells RIF model were induced with transforming growth factorβ1(TgF-β1).Effects of different concentrations of curcumin(0,10,20,and 30μmol/L)on cell proliferation,cell cycle,cell apoptosis as well as cyclin D1 expression were analyzed by cell counting kit-8,flow cytometry and Western blot,***18 methylation levels were determined by methylation-specific polymerase chain ***18,fibronectin(FN),type I collagen(Col-I)and alpha-smooth muscle actin(α-SMA)mRNA and protein expressions were analyzed by real-time PCR(RT-PCR)and Western blot,***,cells were treated with 50 mmol/L 5-aza-2′-deoxycytidine(5-aza-dC,demethylation agent)for 72 *** of curcumin on extracellular matrix(ECM)deposition was evaluated by immunochemical staining and Western ***-49F cells were transfected with ADAMTS18 small interfering RNA and grouped into a normal control,ADAMTS18-knock-out(KO),and ADAMTS18-KO+30μmol/L curcumin groups,and whether curcumin can reverse the effect of ADAMTS18 knockdown on RIF was *** Compared with the control group,TgF-β1 significantly inhibited the proliferation of NRK-49F cells,blocked the g1/g0 phase,promoted cell apoptosis and inhibited cyclin D1 expression(Pg the different concentrations of curcumin,30μmol/L curcumin significantly reversed these processes(Pg and Western blot results showed that curcumin significantly inhibited the deposition of FN,Col-I andα-SMA(Pgistic effects,promoting ADAMTS18 expression,removing ADAMTS18 methylation,and reducing ECM ***18 knockdown promoted ECM accumulation,and curcumin reversed this process(PgF-β1-induced fibrosis in NRK-49F ***

关键词： renal fibrosis curcumin Chinese medicine ADAMTS18 methylation modification