检索结果-南通市图书馆

Designing ultrastrong maraging stainless steels with improved uniform plastic strain via controlled precipitation of coherent nanoparticles

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 Materials Science & Technology 2021年第34期93卷 60-70页

作者： Z.h.wang B.Niu Q.wang C.Dong J.C.Jie T.M.wang T.G.Nieh Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Department of Materials Science and Engineering The University of TennesseeKnoxville37996TennesseeUSA

The development of ultrastrong maraging stainless steels(MSSs)is always in high demand.however,traditional high-strength MSSs generally exhibit early plastic instability with a low uniform strain since the precipitated nanoparticles are non-coherent with the body-centered-cubic(BCC)lath martensitic matrix.here,we design a novel ultrahigh strength MSS(Fe-5.30 Cr-13.47 Ni-3.10 Al-1.22 Mo-0.50 W-0.23 Nb-0.03 C-0.005 B,wt.%)using a cluster formula approach.A fabulous microstructure consisting of a uniform distribution of high-density coherent B2-Ni Al nanoprecipitates(3-5 nm)in BCC martensitic matrix was successfully obtained.This alloy has not only an exceedingly high ultimate tensile strength of 2.0 GPa,but also a decent uniform elongation of 4.2%-5.1%,which is almost triple of the value observed in existing MSSs.We present an in-depth discussion on the origins of ultrahigh strength and uniform plastic strain in the new alloy to validate our design strategy and further offer a new pathway to exploit highperformance MSSs.

关键词： Maraging stainless steel Ultrahigh strength Coherent precipitation Strengthening mechanisms Uniform deformation

Effect of hyperbaric oxygen therapy on neuropathic pain and its mechanism

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Nautical Medicine and hyperbaric Medicine 2024年第2期31卷 224-228页

作者： Chen W. Wang H. wang X. Liu C. Chen Y. Department of Anesthesiology The First Affiliated Hospital of Wannan Medical College Wuhu 241000 China Department Of Cardiac Surgery The First Affiliated Hospital of Wannan Medical College Wuhu 241000 China Department of Cardiac Surgery Maanshan People's Hospital Maanshan 243000 China

Objective To explore the mechanism of hyperbaric oxygen（hBO）therapy for alleviating neuropathic pain. Methods A total of 96 adult healthy male C57BL/6J mice were divided into three groups，according to the random number table method：sham group（group S），model of chronic compression injury group（group C），and hBO group（group h），with 32 mice in each group. The neuropathic pain model in the group C and group h was established by chronic compression injury（CCI）of sciatic nerve，and sham operation was performed only in the group S. The mice in the group h were treated with hBO on the first day after operation，once a day for five consecutive days. The mice in the group S and group C were simply placed in oxygen chamber without hBO treatment. After modeling，the mechanical withdrawal threshold （MWT） and thermal withdrawal latency （TWL） were measured on postoperative days 1，3，5，7，14，21，and 28，respectively. On postoperative days 7，14，21，and 28，eight mice were euthanized in each group and the right dorsal root ganglia were harvested. The mRNA expression levels of hIF-1α，iNOS，Arg-1，TNF-α，IL-6，and IL-10 in the dorsal root ganglia of each group were determined by RT-qPCR.Results Compared with the group S，at each postoperative time point，the group C had lower MWT and shorter TWL（Phigher mRNA expression levels of hIF-1α，iNOS，TNF-α，and IL-6，and lower mRNA expression levels of IL-10 and Arg-1 （Ph the group C，the mice in the group h showed significant increases in MWT and TWL on postoperative days 1，3，7，and 14（Phe mRNA expression levels of hIF-1α，TNF-α，IL-6，and iNOS were significantly decreased，while the mRNA expression levels of Arg - 1 and IL - 10 were significantly increased （PhBO therapy is effective for short - term relief of neuropathic pain in mice，and its mechanism may be related to the regulation of macrophage polarization mediated by hIF - 1α and its anti - inflammatory effects. © 2024 Chinese Medical Journa

关键词： hyperbaric oxygen Mechanical withdrawal threshold Neuropathic pain Thermal withdrawal latency

Current understanding of the origin of equiaxed grains in pure metals during ultrasonic solidification and a comparison of grain formation processes with low frequency vibration,pulsed magnetic and electric-current pulse techniques

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 Materials Science & Technology 2021年第6期65卷 38-53页

作者： Nagasivamuni Balasubramani Gui wang David h.St John Matthew S.Dargusch Centre for Advanced Materials Processing and Manufacturing(AMPAM) School of Mechanical and Mining EngineeringUniversity of QueenslandSt Lucia

The formation of fine,non-dendritic equiaxed grains throughout a casting without the addition of refiners(i.***.independent of alloy chemistry),is made possible by using ultrasonic,magnetic or pulsed magnetic and electric current pulse techniques.The dominant mechanisms proposed for the grain refinement produced during the application of an external field are cavitation phenomena assisted nucleation or fragmentation of dendrites(ultrasonic field),wall crystals arising from the cold surface of the mould(electric current pulse,magnetic and pulsed magnetic fields).In all these cases fluid flow provides an additional contribution(e.***.reduced temperature gradients,growth rate and remelting of dendrites)to maintaining an equiaxed grain structure.The origin of equiaxed grains under an external field also depends on the casting conditions(volume and shape of casting)and the type of alloy other than the mechanisms specific to a particular technique.The current work aims to provide a detailed understanding of the various factors and mechanisms that influence the grain refinement achieved during the solidification of pure metals(magnesium and zinc)subjected to Ultra Sonic Treatment(UST).The role of the temperature range of UST application,time duration and an unpreheated sonotrode are examined with respect to the origin,evolution of equiaxed grain structure,morphology and the columnar to equiaxed transition.The origin of grains was analysed from three fundamental aspects that contribute to refinement(i)heterogeneous nucleation(ii)fragmentation of existing dendrites and(iii)grains produced from the colder surfaces(arising from mould walls or vibrating surfaces as wall crystals).A comparison of UST refinement with mechanical,low-frequency vibration,electric current pulse and magnetic field solidification of pure metals has also been provided to highlight the importance of the cold surfaces(sonotrode and mould wall)in influencing grain refinement.

关键词： Ultrasonic treatment Grain refinement Equiaxed grains Magnesium Zinc Solidification

Adiabatic shear instability in a titanium alloy:Extreme deformation-induced phase transformation,nanotwinning,and grain refinement

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19期150卷 104-113页

作者： X.R.Guan Q.Chen S.J.Qu G.J.Cao h.wang A.h.Feng D.L.Chen School of Materials Science and Engineering Tongji UniversityShanghai 201804China Southwest Technology and Engineering Research Institute Chongqing 400039China Shanghai Key Laboratory of D&A for Metal-Functional Materials School of Materials Science&EngineeringTongji UniversityShanghai 201804China Key Laboratory for Light-weight Materials Nanjing Tech UniversityNanjing 210009China Interdisciplinary Center for Additive Manufacturing School of Materials and ChemistryUniversity of Shanghai for Science and TechnologyShanghai 2000093China Department of Mechanical and Industrial Engineering Toronto Metropolitan University(formerly Ryerson University)TorontoON M5B 2K3Canada

Increasingly harsh service conditions place higher requirements for the high strain-rate performance of titanium alloys.Adiabatic shear band(ASB),a phenomenon prone to dynamic loading,is often accom-panied by catastrophic damage.Yet,it is unclear how the internal nanostructures are related to shear instability.here we report detailed microstructural evolution in the ASB of a titanium alloy via in-depth focused ion beam(FIB),transmission Kikuchi diffraction(TKD),and high-resolution transmission electron microscope(hRTEM)analyses,with the deformation instability phenomenon discussed from the energy perspective.The ASB interior undergoes multifaceted changes,namely deformation-induced beta-to-alpha transformation and deformation-induced martensitic transformation to form substantially refined and heterogeneous structures.Meanwhile,two types of extremely fine twins are identified to occur within both nano-sized martensite and alpha phase.The critical plastic work representing the onset of adiabatic shear instability and dynamic equilibrium is observed to be constant for a specific structure in the same deformation mode.The energy analysis could be extended to other materials subjected to high strain-rate dynamic deformation.

关键词： Adiabatic shear instability Deformation-induced phase transformation Deformation-induced nanotwinning Dynamic recovery Energy analysis

Computer-based Creativity Enhanced Conceptual Design Model for Non-routine Design of Mechanical Systems

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 Mechanical Engineering 2014年第6期27卷 1083-1098页

作者： LI Yutong wang Yuxin DUFFY Alex h B Department of Mechanical & Electrical Engineering China University of Petroleum Design Manufacture and Engineering ManagementUniversity of Strathclyde

Computer-based conceptual design for routine design has made great strides, yet non-routine design has not been given due attention, and it is still poorly automated. Considering that the function-behavior-structure（FBS） model is widely used for modeling the conceptual design process, a computer-based creativity enhanced conceptual design model（CECD） for non-routine design of mechanical systems is presented. In the model, the leaf functions in the FBS model are decomposed into and represented with fine-grain basic operation actions（BOA）, and the corresponding BOA set in the function domain is then constructed. Choosing building blocks from the database, and expressing their multiple functions with BOAs, the BOA set in the structure domain is formed. Through rule-based dynamic partition of the BOA set in the function domain, many variants of regenerated functional schemes are generated. For enhancing the capability to introduce new design variables into the conceptual design process, and dig out more innovative physical structure schemes, the indirect function-structure matching strategy based on reconstructing the combined structure schemes is adopted. By adjusting the tightness of the partition rules and the granularity of the divided BOA subsets, and making full use of the main function and secondary functions of each basic structure in the process of reconstructing of the physical structures, new design variables and variants are introduced into the physical structure scheme reconstructing process, and a great number of simpler physical structure schemes to accomplish the overall function organically are figured out. The creativity enhanced conceptual design model presented has a dominant capability in introducing new deign variables in function domain and digging out simpler physical structures to accomplish the overall function, therefore it can be utilized to solve non-routine conceptual design problem.

关键词： conceptual design non-routine design creative enhance model computer-based approach mathematical expression

MhC class Ⅰ-independent activation of virtual memory CD8 T cells induced by chemotherapeutic agent-treated cancer cells

在线全文

学校读者我要写书评

暂无评论

Cellular & Molecular Immunology 2021年第3期18卷 723-734页

作者： Xiaoguang wang Brittany C.Waschke Rachel A.Woolaver Samantha M.Y.Chen Zhangguo Chen Jing h.wang Department of Immunology and Microbiology University of ColoradoAnschutz Medical CampusAuroraCO 80045USA

Cancer cells can evade immune recognition by losing major histocompatibility complex(MhC)class Ⅰ.hence,MhC class Ⅰ-negative cancers represent the most challenging cancers to treat.Chemotherapeutic drugs not only directly kill tumors but also modulate the tumor immune microenvironment however,it remains unknown whether chemotherapy-treated cancer cells can activate CD8 T cells independent of tumor-derived MhC class Ⅰ and whether such MhC class Ⅰ-independent CD8 T-cell activation can be exploited for cancer immunotherapy.here,we showed that chemotherapy-treated cancer cells directly activated CD8 T cells in an MhC class Ⅰ-independent manner and that these activated CD8 T cells exhibit virtual memory(VM)phenotypes.Consistently,in vivo chemotherapeutic treatment preferentially increased tumor-infiltrating VM CD8 T cells.Mechanistically,MhC class Ⅰ-independent activation of CD8 T cells requires cell-cell contact and activation of the PI3K pathway.VM CD8 T cells contribute to a superior therapeutic effect on MhC class Ⅰ-deficient tumors.Using humanized mouse models or primary human CD8 T cells,we also demonstrated that chemotherapy-treated human lymphomas activated VM CD8 T cells independent of tumor-derived MhC class Ⅰ.In conclusion,CD8 T cells can be directly activated in an MhC class Ⅰ-independent manner by chemotherapy-treated cancers,and these activated CD8 T cells may be exploited for developing new strategies to treat MhC class Ⅰ-deficient cancers.

关键词： DNA-damaging agents B-cell lymphomas virtual memory CD8 T cells cancer immunotherapy MhC classⅠ

Ordering-induced Elinvar effect over a wide temperature range in a spinodal decomposition titanium alloy

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 Materials Science & Technology 2023年第19期150卷 245-255页

作者： D.L.Gong h.L.wang S.h.hao P.Liu X.Yang Y.N.Jiang W.J.wang K.Lin B.Li K.Du Y.D.wang R.Yang Y.L.hao Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Analysis and Testing Center Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryDepartment of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

Temperature-independent elastic modulus is termed as Elinvar effect,which is available by tuning the continuous spin transition of ferromagnetic alloys via composition optimization and the first-order martensitic transformation of shape memory alloys via plastic deformation.however,these reversible mechanisms are restricted generally in a narrow temperature range of less than 300 K.here reports,by tuning a spinodal decomposition in a Ti-Nb-based titanium alloy via aging treatment,both the Elinvar effect in a wide temperature range of about 500 K and a high strength-to-modulus ratio of about 1.5%can be obtained by a continuous and reversible crystal ordering mechanism.The results demonstrate that the alloy aged at 723 K for 4 h has a nanoscale plate-like modulatedβ+α"two-phase microstructure and its elastic modulus keeps almost constant from 100 to 600 K.Synchrotron and in-situ X-ray diffraction measurements reveal that the crystal ordering parameter of theα"phase increases linearly with temper-ature from 0.88 at 133 K to 0.97 at 523 K but its volume fraction keeps a constant of about 33.8%.This suggests that the continuous ordering of theα"phase toward the high modulusαphase induces a posi-tive modulus-temperature relation to balance the negative relation of the elastically stableβphase.The aged alloy exhibits a high yield strength of 1200 MPa,good ductility of 16%and a high elastic admissible strain of 1.5%.Our results provide a novel strategy to extend the Elinvar temperature range and enhance the strength by tuning the crystal ordering of decomposition alloys.

关键词： Titanium alloy Spinodal decomposition Crystal ordering Elinvar effect Mechanical properties

Decomplexation of Cu-1-hydroxyethylidene-1,1-diphosphonic acid by a three-dimensional electrolysis system with activated biochar as particle electrodes

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 Environmental Sciences 2023年第2期124卷 630-643页

作者： Xing wang Zilong Zhao hongjie wang Feng wang Wenyi Dong School of Civil and Environmental Engineering Harbin Institute of Technology ShenzhenShenzhen 518055China Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control Shenzhen 518055China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

The feasibility of decomplexation removal of typical contaminants in electroplating wastewater,complexed Cu(Ⅱ)with 1-hydroxyethylidene-1,1-diphosphonic acid(Cu-hEDP),was first performed by a three-dimensional electrode reactor with activated biochar as particle electrodes.For the case of 50 mg/L Cu-hEDP,Cu(Ⅱ)removal(90.7%)and PO_(4)^(3−)conversion(34.9%)were achieved under the conditions of electric current 40 mA,initial ph 7,acid-treated almond shell biochar(AASB)addition 20 g/L,and reaction time 180 min,with second-order rate constants of 1.10×10^(−3) and 1.94×10^(−5) min^(−1) respectively.The growing chelating effect between Cu(II)and hEDP and the comprehensive actions of adsorptive accumulation,direct and indirect oxidation given by particle electrodes accounted for the enhanced removal of Cu-hEDP,even though the mineralization of hEDP was mainly dependent on anode oxidation.The performance attenuation of AASB particle electrodes was ascribed to the excessive consumption of oxygen-containing functionalities during the reaction,especially acidic carboxylic groups and quinones on particle electrodes,which decreased from 446.74 to 291.48μmol/g,and 377.55 to 247.71μmol/g,respectively.Based on the determination of adsorption behavior and indirect electrochemical oxidation mediated by in situ electrogenerated h_(2)O_(2) and reactive oxygen species(e.g.,•Oh),a possible removal mechanism of Cu-hEDP by three-dimensional electrolysis was further proposed.

关键词： Cu-hEDP Electrochemical oxidation Particle electrode Reaction characteristics Removal mechanism

Small-signal Angular Stability of Power System as Affected by Grid-connected Variable Speed Wind Generators—A Survey of Recent Representative Works

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2017年第3期3卷 223-231页

作者： Wenjuan Du Jingtian Bi h.F.wang State Key Laboratory of Alternate Electric Power Systems(SKLAEPS)with New Energy Resources North China Electric Power UniversityBeijing 102206China

This paper reviews the status and progress of the investigation on power system small-signal angular stability as affected by grid-connected variable speed wind generators(VSWGs).The review is carried out on the basis of a survey of recently published representative papers.Strategies of the investigation made in those selected papers are classified into two groups:1)VSWGs displacing synchronous generators(SGs);2)VSWGs simply being added in a power system.The diversification of the results of the investigation is highlighted in the survey.Careful analysis on two strategies of the investigation is conducted in this paper.It is revealed that in the strategy of VSWGs displacing SGs,there are two factors which could affect power system small-signal angular stability differently:1)Withdrawing the SGs’dynamics;2)adding the VSWGs’dynamics.In the strategy of adding VSWGs in the power system,there are also two affecting factors:1)Change of load flow brought about by the VSWGs;2)dynamic interactions with the SGs introduced by the VSWGs.hence diversified results of the investigation obtained so far are not only due to the dependence of the investigation on sample power systems used,but also caused by the mixture of different affecting factors.This paper is concluded with a summary of key issues of the investigation for future work.

关键词： Electromechanical oscillation modes power system dynamics power system low-frequency oscillation power system small-signal angular stability synchronous generators(SGs) variable speed wind generators(VSWGs)