检索结果-南通市图书馆

International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1089-1097页

作者： Jianjun xu Hanlin Ding Xin lin feng Liu Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics.

关键词： directed energy deposition Ni-based superalloys high-temperature preheating hot isostatic pressing microstructure tensile properties

Melt flow,heat transfer and solidification in a flexible thin slab continuous casting mold with vertical-combined electromagnetic braking

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2期31卷 401-415页

作者： lin xu Ze-feng Han Christian Karcher En-gang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina Key Laboratory of Liaoning Province for Clean Combustion Power Generation and Heating Technology Shenyang Institute of EngineeringShenyang110136LiaoningChina Institute of Thermodynamics and Fluid Mechanics Technische Universität IlmenauIlmenau98684Germany

During continuous casting of steel slabs,the application of electromagnetic braking technology(EMBr)provides an effective tool to influence solidification by controlling the pattern of melt flow in the mold.Thus,the quality of the final product can be improved considerably.A new electromagnetic braking(EMBr)method,named vertical-combined electromagnetic braking(VC-EMBr),is proposed to be applied to a flexible thin slab casting(FTSC)mold.To evaluate the beneficial effects of the VC-EMBr,the melt flow,heat transfer,and solidification processes in the FTSC mold are studied by means of numerical simulations.In detail,a Reynolds-averaged Navier–Stokes turbulence model together with an enthalpy-porosity approach was used.The numerical findings are compared with respective simulations using the traditional Ruler-EMBr.The results demonstrate that the application of the VC-EMBr contributes significantly to preventing relative slab defects.In contrast to the Ruler-EMBr,the additional vertical magnetic poles of the VC-EMBr preferentially suppress the direct impact of jet flow on the narrow face of FSTC mold and considerably diminish the level fluctuation near the meniscus region.For instance,by applying a magnetic flux density of 0.3 T,the maximum amplitude of meniscus deflection reduces by about 80%.Moreover,the braking effect of the VC-EMBr effectively improves the homogeneity of temperature distribution in the upper recirculation region and increases the solidified shell thickness along the casting direction.On this basis,the newly proposed VC-EMBr shows a beneficial effect in preventing relative slab defects for FTSC thin slab continuous casting.

关键词： Electromagnetic braking Mold Melt flow Heat transfer Solidification

RIOK1 synergizes with TRIP13 by regulating the E2F-Rb signaling pathway to promote the proliferation of esophageal cancer cells

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

Genes & Diseases 2024年第3期11卷 55-58页

作者： Chengyu Li Deyuan Pan Wan lin Danxia Deng Yingxin Zhou Hui Zhao feng Pan Liyan xu Enmin Li lin Long The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area Department of Biochemistry and Molecular BiologyShantou University Medical CollegeShantouGuangdong 515041China Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology Institute of Oncologic PathologyShantou University Medical CollegeShantouGuangdong 515041China Institute of Basic Medical Science Cancer Research CenterShantou University Medical CollegeShantouGuangdong 515041China Clinical Research Center Shantou Central HospitalShantouGuangdong 515041China

Esophageal cancer is one of the leading causes of cancer death in the world,with approximately half of the new cases occurring in China every year.^(1)Esophageal squamous cell carcinoma(ESCC)is the main subtype,accounting for more than 90%,and the five-year survival rate is less than 10%.Using large-scale genome analysis,many driver mutations and key pathways associated with ESCC have been identified.However,these genomic signatures have not improved the clinical management of EscC patients,or established effective targeted therapy.^(2)Esophageal cancer still lacks representative molecular markers.

关键词： cancer esophageal Esophageal

In situ atomic-scale tracking of unusual interface reaction circulation and phase reversibility in(de)potassiated alloy-typed anode

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 Energy Chemistry 2024年第8期95卷 241-249页

作者： lin Su Ruining Fu Shuangying Lei Yuchen Pan Chongyang Zhu Pengcheng Liu feng xu SEU-FEI Nano-Pico Center Key Laboratory of MEMS of the Ministry of Education Southeast University

Alloy-typed anode materials,endowed innately with high theoretical specific capacity,hold great promise as an alternative to intercalation-typed counterparts for alkali-ion batteries.Despite tremendous efforts devoted to addressing drastic volume change and severe pulverization issues of such anodes,the underlying mechanisms involving dynamic phase evolutions and reaction kinetics have not yet been fully comprehended.Herein,taking antimony（Sb） anode as a representative paradigm,its microscopic operating mechanisms down to the atomic scale during live（de）potassiation cycling are systematically unraveled using in situ transmission electron microscopy.Highly reversible phase transformations at single-particle level,that are Sb■KSb2■KSb■K5Sb4■K3Sb,were revealed during cycling.Meanwhile,multiple phase interfaces associated with different reaction kinetics coexisted and this phenomenon was properly elucidated in the context of density functional theory calculations.Impressively,previously unexplored unidirectional circulation of reaction interfaces within individual Sb particle is confirmed for both potassiation and depotassiation.Based on the empirical results,the surface diffusion-mediated potassiation-depotassiation pathways at single-particle level are suggested.This work affords new insights into energy storage mechanisms of Sb anode and valuable guidance for targeted optimization of alloy-typed anodes（not limited to Sb） toward advanced potassium-ion batteries.

关键词： Alloy-typed anode In situ transmission electron microscopy Potassium storage mechanism Reaction interface

Combination of methylthio-chemistry with living crystallization-driven self-assembly toward uniformπ-conjugated nanostructures with antibacterial activity,surface tailorability,tunable morphology and dimension

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第7期67卷 2341-2352页

作者： Chuyu Duan Binbin xu Ruru Li Xiaoyu Huang Shaoliang lin Chun feng Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Living crystallization-driven self-assembly(CDSA)provides robust access to uniformπ-conjugated nanostructures(CNSs)from block copolymers(BCPs)containing a crystallineπ-conjugated segment with controlled dimension,morphology and composition,which show appealing applications in biomedicine,photocatalysis and microelectronics.To further expand the application spectrum of these CNSs,the development of facile strategies toward diverse CNSs with varying structures/functionalities is highly desired.Herein,BCPs consisting of oligo(p-phenylene ethynylene)-b-poly(polypropyl-3-methanethiol acrylate)(OPE_(9)-bPMTPA35and OPE_(9)-b-PMTPA_(58);the subscript represents the number of repeat unit of each block)consisting of a crystallineπ-conjugated core-forming OPE_(9)segment and a corona-forming PMTPA block are synthesized.By efficient“click-type”alkylation of methylthio groups,OPE_(9)-b-PMTPA with varying contents of sulfonium unit is obtained.Uniform ribbon-like micelles with different widths and lengths can then be generated in a controlled manner via the self-seeding approach of living CDSA.Additionally,negatively charged polymeric and Ag nanoparticles can be immobilized on sulfonium/methylthio-containing shells by taking advantage of electrostatic attraction and coordination interaction,respectively.Interestingly,the ribbon-like micelles with positively charged shells exhibit antibacterial activity against E.coli.Given the ease of modification of PMTPA-based shell and attractive opto-electronic/photocatalytic properties ofπ-conjugated units,the combination of methylthio-chemistry and living CDSA opens a new avenue to generate multi-functional CNSs for widespread applications from biomedicine to photocatalysis.

关键词： crystallization-driven self-assembly block copolymer π-conjugated nanostructure methylthio-chemistry

Efficacy and safety of electroacupuncture for insomnia:A systematic review and meta-analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第4期22卷 459-472页

作者： Han-yu xu lin-na Wu Yuan Zhang Te Ba Xiao-feng Zhao Acupuncture and Moxibustion Department First Teaching Hospital of Tianjin University of Traditional Chinese Medicine National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion

Background:Electroacupuncture is often used to treat insomnia.Objective:To evaluate the efficacy and safety of electroacupuncture for insomnia.Search strategy:Databases including PubMed,Cochrane Library,Embase,Web of Science,Chinese Biomedical Literature Database,China National Knowledge Infrastructure,Wanfang Data and VIP Fulltext e-Journals Database were searched up to January 15,2023.Inclusion criteria:Randomized clinical trials were included if they compared the clinical efficacy and safety of electroacupuncture with sham acupuncture,no treatment or usual care (UC) and general acupuncture.Data extraction and analysis:The full texts of the studies were reviewed to remove ineligible literature.The extracted data included authors,publication year,diagnostic criteria,sample size,population characteristics,interventions and outcomes.The above steps were performed independently by two reviewers and the data were cross checked.Stata15.0 software was used to analyze the extracted outcome data.For continuous data (Pittsburgh Sleep Quality Index[PSQI]score and Insomnia Severity Index score),weighted mean difference (WMD) was calculated and 95% confidence interval (CI) was reported when the same scale was applied.For dichotomous variables (clinical response rate and adverse events),a meta-analysis was performed using risk ratio (RR) as the effect indicator.Results:Thirty-one trials with 2226 subjects were included.The meta-analysis suggested that electroacupuncture was more effective in improving insomnia compared with the control group (sham acupuncture,no treatment,UC and general acupuncture)(RR=1.21;95 CI:[1.16,1.27]),significantly reducing the PSQI score in insomnia patients after treatment and at follow-up (WMD=-3.23;95%CI:[-4.29,-2.17];P<0.001).There was no significant difference in the incidence of adverse events between the EA and control groups (sham acupuncture and no treatment or UC.RR=1.48;95%CI:[0.91,2.40];P=0.117).In addition,the regression results revealed that receiving electroacupuncture for seven to ni

关键词： Electroacupuncture Insomnia Meta-analysis Systematic review

Microstructure evolution and phase transformation of the mushy zone in a quenchedβ-solidifying TiAl alloy

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 Materials Science & Technology 2024年第2期169卷 28-41页

作者： Fuqiang Zhang Xianfei Ding Leming xu Xin feng Hai Nan Jianping He Yongfeng Liang Junpin lin State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Cast Titanium Alloy R&D Center Beijing Institute of Aeronautical MaterialsBeijing 100095China

This study investigates the phase constitutions and transformations that occur in the mushy zone and in the adjacent phase fields of a directionally solidified Ti-44Al-8Nb-1Cr alloy via quenching technique.The results indicate that the mushy zone consists of unmeltedβdendrites and interdendritic liquid,whose formation can be attributed to the difference in melting point aroused by local heterogeneity in solutecontent.Theβdendrite is composed of numerous subgrains with various orientations.During quenching,theβdendrite transforms into Widmanstättenαvia a precipitation reaction,owing to the decreasing cooling rate caused by heat transfer from the surrounding liquid.Additionally,after quenching,the interdendritic liquid is transformed intoγplates.Within the singleβphase field and the lower part of the mushy zone,a massive transformation ofβtoγoccurs.Conversely,in theβ+αphase field,bothβandαphases are retained to ambient temperature.During the heating process,the transformation ofα→βgives rise to the formation ofβvariants,which affects the orientation ofβdendrites in the mushy zone.The growth kinematics of theα→βtransformation was elucidated,revealing the preferential growth directions of111and112forβvariants.Furthermore,this study presents an illustration of the formation process of the mushy zone and the microstructural evolution during the heating and quenching process.

关键词： Titanium aluminides Mushy zone Quenching Electron backscattering diffraction Phase transformation

Experimental quantum state compression from two identical qubits to a qutrit

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

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 1-5页

作者： Qiao xu lin-Xiang Zhou Tian-feng feng Shang-feng Qiu Si-Wu Li Wu-Ji Zhang Hui Luo Xiao-Qi Zhou State Key Laboratory of Optoelectronic Materials and Technologies and School of Physics Sun Yat-sen UniversityGuangzhou 510000China Hefei National Laboratory Hefei 230088China

In the realm of modern information technology,data compression technology occupies a pivotal position.With advancements in quantum information technology,the need to compress large-scale qubits ensembles has become urgent,aiming to reduce the demand on quantum storage resources.However,existing quantum state compression schemes generally face a limitation:the particles before and after compression must reside in the same dimensional space.In specific scenarios,compressing qubits into particles of higher dimensions not only enhances the efficiency of quantum state compression but also further reduces the usage of quantum storage resources.Here we experimentally demonstrated a quantum state compression between particles of different dimensions,successfully compressing two qubits into a single qutrit.The average fidelity of the resulting qutrit with the ideal quantum state is 0.8835.Our study may have potential applications in future quantum information,such as increasing quantum communication bandwidth and reducing storage resource consumption in quantum computing.

关键词： quantum state compression quantum information technology optics

Seasonal Characteristics of Forecasting Uncertainties in Surface PM_(2.5)Concentration Associated with Forecast Lead Time over the Beijing-Tianjin-Hebei Region

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第5期41卷 801-816页

作者： Qiuyan DU Chun ZHAO Jiawang feng Zining YANG Jiamin xu Jun GU Mingshuai ZHANG Mingyue xu Shengfu lin Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei 230026China

Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality forecasts.However,the particular impact of meteorological forecasting uncertainties on air quality forecasts specific to different seasons is still not well known.In this study,a series of forecasts with different forecast lead times for January,April,July,and October of 2018 are conducted over the Beijing-Tianjin-Hebei(BTH)region and the impacts of meteorological forecasting uncertainties on surface PM_(2.5)concentration forecasts with each lead time are investigated.With increased lead time,the forecasted PM_(2.5)concentrations significantly change and demonstrate obvious seasonal variations.In general,the forecasting uncertainties in monthly mean surface PM_(2.5)concentrations in the BTH region due to lead time are the largest(80%)in spring,followed by autumn(~50%),summer(~40%),and winter(20%).In winter,the forecasting uncertainties in total surface PM_(2.5)mass due to lead time are mainly due to the uncertainties in PBL heights and hence the PBL mixing of anthropogenic primary particles.In spring,the forecasting uncertainties are mainly from the impacts of lead time on lower-tropospheric northwesterly winds,thereby further enhancing the condensation production of anthropogenic secondary particles by the long-range transport of natural dust.In summer,the forecasting uncertainties result mainly from the decrease in dry and wet deposition rates,which are associated with the reduction of near-surface wind speed and precipitation rate.In autumn,the forecasting uncertainties arise mainly from the change in the transport of remote natural dust and anthropogenic particles,which is associated with changes in the large-scale circulation.

关键词： PM_(2.5) forecasting uncertainties forecast lead time meteorological fields Beijing-Tianjin-Hebei region

Progress in processing of porous titanium: a review

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1932-1955页

作者： Xiao-Li Yang Xian-feng Du Zhi-lin xu Zhong-Shuai Liang Li-Long Xiong Engineering Research Center of Energy Storage Materials and Devices Ministry of Education School of Chemistry Xi'an Jiaotong University

As a novel structural and functional material,porous titanium and its alloys have been widely used in the aerospace, marine engineering and biomedical fields due to their high corrosion resistance, low density, good biocompatibility and excellent mechanical properties. Therefore, in this paper, a comprehensive review of powder metallurgy(PM)(including additive manufacturing(AM)processes) for fabricating porous titanium is firstly covered in terms of their working principles, capabilities, shortcomings and strengths. Simultaneously, the influencing factors of various methods on final pore structure of porous Ti are involved. Secondly, a summary of the chemical methods(CM) to obtain the porous Ti is also provided,such as dealloying method and reduction method. Finally,the tendency and direction of preparation technology as well as application of porous titanium were prospected.

关键词： Porous titanium Powder metallurgy Chemical method Pore structure Processing process