检索结果-南通市图书馆

effects of small additions of Zn on the microstructure, mechanical properties and corrosion resistance of We43B Mg alloys

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 858-868页

作者： A.v. Koltygin v.e. Bazhenov R.S. Khasenova A.A. Komissarov A.I. Bazlov v.A. Bautin Foundry Department National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Hybrid Nanostructured Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Advanced Green Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Department of Metallurgy Steel New Production Technologies and Protection of Metals National University of Science and Technology “MISiS” Moscow 119049 Russia

Zn is a commonly used alloying element for Mg alloys owing to its beneficial effects on mechanical properties. To improve the mechanical and corrosion properties of We43B Mg alloys, the effects of 0–0.7wt% Zn addition on the microstructure and properties of sample alloys were investigated. Addition of Zn to as-cast We43B alloy promoted the formation of the Mg12Nd phase;by contrast, after T6 heat treatment, the phase composition of We43B alloys with and without Zn addition remained mostly the same. A long-period stacking ordered phase was predicted by CALPHAD calculation, but this phase was not observed in either the as-cast or heat-treated Zn-containing We43B alloys. The optimum temperature and duration of T6 heat treatment were obtained using CALPHAD calculations and hardness measurements. Addition of Zn resulted in a slight reduction in the average grain size of the as-cast and T6 heat-treated We43B alloys and endowed them with increased corrosion resistance with little effect on their mechanical properties.

关键词： magnesium alloys corrosion resistance mechanical properties Zn addition

Adiponectin,the past two decades

在线全文

学校读者我要写书评

暂无评论

Journal of Molecular Cell Biology 2016年第2期8卷 93-100页

作者： Zhao v.Wang Philipp e.Scherer Division of Cardiology Department of Internal MedicineUniversity of Texas Southwestern Medical Center5323 Harry Hines Blvd.DallasTX 75390USA Touchstone Diabetes Center Department of Internal MedicineUniversity of Texas Southwestern Medical Center5323 Harry Hines Blvd.DallasTX 75390USA Department of Cell Biology University of Texas Southwestern Medical Center5323 Harry Hines Blvd.DallasTX 75390USA

Adiponectin is an adipocyte-specific factor,first described in *** the past two decades,numerous studies have elucidated the physiological functions of adiponectin in obesity,diabetes,inflammation,atherosclerosis,and cardiovascular ***,elicited through cognate receptors,suppresses glucose production in the liver and enhances fatty acid oxidation in skeletal muscle,which together contribute to a beneficial metabolic action in whole body energy *** its role in metabolism,adiponectin also protects cells from apoptosis and reduces inflammation in various cell types via receptor-dependent ***,as a fat-derived hormone,therefore fulfills a critical role as an important messenger to communicate between adipose tissue and other organs.A better understanding of adiponectin actions,including the pros and cons,will advance our insights into basic mechanisms of metabolism and inflammation,and potentially pave theway toward novel means of pharmacological intervention to address pathophysiological changes associated with diabetes,atherosclerosis,and cardiometabolic disease.

关键词： adiponectin diabetes obesity metabolic syndrome

Ultrasensitive detection of DNA and protein markers in 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

Cancer Biology & Medicine 2015年第3期12卷 143-149页

作者： Irina v.Smolina Natalia e.Broude Department of Biomedical engineering Boston University

Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is a major challenge in cancer research, detection, and effective treatment. As such, the use of diagnostic methods is important to reveal this heterogeneity at the single-cell level. Droplet microfluidic devices are effective tools that provide exceptional sensitivity for analyzing single cells and molecules. In this review, we highlight two novel methods that employ droplet microfluidics for ultrasensitive detection of nucleic acids and protein markers in cancer cells. We also discuss the future practical applications of these methods.

关键词： Microfluidic droplets rolling circle amplification (RCA) peptide nucleic acids (PNA) cell-surface protein marker

ＣＯＭＰＬＥＸＩＴＹＯＦＬＡＲＧＥＴＩＭＥＢＥＨＡＶＩＯＵＲＯＦＥＶＯＬＵＴＩＯＮＥＱＵＡＴＩＯＮＳＷＩＴＨＢＯＵＮＤＥＤＤＡＴＡ

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2002年第2期23卷 293-310页

作者： J.L.vZQUeZ e.ZUAZUA Departamento de Matematicas Universidad AutonomaDepartamento de Matematica AplicadaUniversidadComplutense 28049MadridSpain28040 M

The authors study the asymptotic behaviour of solutions of the heat equation and a number of evolution equations using scaling techniques. It is proved that in the framework of bounded data stabilization need not occur and the general asymptotic behaviour is complex. This behaviour reflects for large times, even on compact sets, the complexity of the initial data at infinity.

关键词： Asymptotic behaviour Scaling Omega-limit Heat equation Hyperbolic conservation laws

Influence of the safety factor profile on the particle and heat transport in the Globus-M spherical tokamak

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第11期21卷 1-6页

作者： A YU TeLNOvA G S KURSKIev e O KISeLev N N BAKHARev v K GUSev N A KHROMOv S YU MeDveDev v B MIINAev I v MIROSHNIKOv M I PATROv Yu v PeTROv N v SAKHAROv A D SLADKOMeDOvA P B SHCHeGOLev v v SOLOKHA v A TOKARev S YU TOLSTYAKOv e A TUKHMeNevA Ioffe Institute Saint-Petersburg 194021Russia Keldysh Institute Russian Academy of SciencesMoscow 125047Russia NRC'Kurchatov Institute’ Moscow 123098Russia

The advanced tokamak scenario is a promising operation scenario for ITeR and fusion neutron *** this scenario the minimum value of the safety factor in the center of the plasma exceeds *** the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up *** to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the *** leads to the peaked density profile formation and improvement of the energy confinement *** achieve a high fraction of the bootstrap current,it is necessary to increase the plasma *** the same time,the maximum allowable pressure is limited to the normalized beta limit.

关键词： advanced tokamak mode transport analysis internal transport barriers

Incoherent Oscillations Accompanying Charge Separation in Photosynthetic Reaction Centers

在线全文

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2013年第3期3卷 1-5页

作者： A. G. yakovlev v. A. Shuvalov A.N. Belozersky Institute of Physico-Chemical Biology Moscow State University Moscow Russia Institute of Basic Biological Problems Russian Academy of Sciences Moscow Russia

early events of charge separation in reaction centers (RCs) of bacterial photosynthesis are modeled by kinetic equations with time-dependent rate constants. An illustrative case of regular motion along a “slow” coordinates leading to oscillations in the kinetics is examined. Different schemes of charge separation are investigated. A good fitting of experimental kinetics of native Rba. sphaeroides RCs is achieved in the five states model P*1BAHA↔P*2BAHA↔I↔P+HA↔P+BA with two excited states BAHA and BAHA and three charge separated states I, P+HA and P+BA (P is a primary electron donor, bacteriochlorophyll dimer, BA and HA are an electron acceptor, monomeric bacteriochlorophyll and bacteriopheophytin in active A-branch, respectively). In the model only the first excited state is directly populated by optical excitation. The emission of the two excited states is assumed to be at 905 and 940 nm, respectively. The intermediate state I is assumed to absorb at 1020 nm as well as the P+HA state. The model explains the deep oscillations in the kinetics of the stimulated emission and of the absorption. In the simpler schemes without the I state or with only one excited state the accordance with the experiment is achieved at unreal parameter values. A possible nature of the I and BAHA states and a possible incoherent nature of the oscillations are discussed.

关键词： Photosynthesis Charge Separation Reaction Center electron Transfer

electron-beam Treatment of Tungsten-free TiC/NiCr Cermet Ⅰ:Influence of Subsurface Layer Microstructure on Resistance to Wear during Cutting of Metals

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 Materials Science & Technology 2005年第3期21卷 427-429页

作者： v.e.Ovcharenko BaohaiYU S.G.Psakhie InstituteofStrengthPhysicsandMaterialsScience SiberiaBranchRussianAcademyofSciences2/1AcademicheskyPr.Tomsk634021Russia InstituteofMetalResearch ChineseAcademyofSciences72WenhuaRoadShenyang110016China

An experimental investigation were performed on the effect of the impulse electron-beam irradiation upon microstruc-ture of the surface layer and on wear resistance of a cutting tool for sintered TiC/NiCr cermet. The results showed that the surface electron-beam treatment of the TiC/NiCr cermet is an efficient method for investigating the mi-crostructure and phase composition in the surface layer of the powder composite and there are optimal regimes of electron-beam treatment, which ensure a substantial increase in the resistance of the cermet to wear during cutting of metals.

关键词： Cermet TiC/NiCr electron-beam treatment Microstructure Wear resistance

Gate-Dependent Nonlinear Hall effect at Room Temperature in Topological Semimetal GeTe

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2023年第7期40卷 63-67页

作者： N.N.Orlova A.v.Timonina N.N.Kolesnikov e.v.Deviatov Institute of Solid State Physics of the Russian Academy of Sciences ChernogolovkaMoscow District2 Academician Ossipyan str.142432Russia

We experimentally investigate nonlinear Hall effect as zero-frequency and second-harmonic transverse voltage responses to ac electric current for topological semimetal GeTe.A thick single-crystal GeTe flake is placed on the Si/SiO_(2) substrate,where the p-doped Si layer serves as a gate *** confirm that electron concentration is not gate-sensitive in thick GeTe flakes due to the gate field screening by bulk *** contrast,by transverse voltage measurements,we demonstrate that the nonlinear Hall effect shows pronounced dependence on the gate electric field at room *** the nonlinear Hall effect is a direct consequence of a Berry curvature dipole in topological media,our observations indicate that Berry curvature can be controlled by the gate electric *** experimental observation can be understood as a result of the known dependence of giant Rashba splitting on the external electric field in *** possible applications,the zero-frequency gate-controlled nonlinear Hall effect can be used for the efficient broad-band rectification.

关键词： temperature. field. curvature

Understanding the mechanisms of friction stir welding based on computer simulation using particles

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2018年第6期14卷 643-656页

作者： A.Yu.Smolin e.v.Shilko S.v.Astafurov e.A.Kolubaev G.M.eremina S.G.Psakhie Institute of Strength Physics and Materials Science SB RAS Tomsk634055Russia Tomsk State University Tomsk634050Russia Skolkovo Institute of Science and Technology Skolkovo143025Russia

Friction stir welding(FSW) is a novel technique for joining different materials without melting. In FSW the welded components are joined by stirring the plasticized material of the welded edges with a special rotating pin plunged into the material and moving along the joint line. From the scientific point of view,the key role of the FSW processes belongs to formation of the special plasticized conditions and activation of physical mechanisms of mixing the materials in such conditions to produce the strong homogeneous weld. But it is still a lack of complete understanding of what are these conditions and *** paper is devoted to understanding the mechanisms of material mixing in conditions of FSW based on a computer simulation using particles. The movable cellular automaton method(MCA), which is a representative of the particle methods in mechanics of materials, was used to perform all ***, material flow including material stirring in FSW is simulated using computational fluid mechanics or smoothed particle hydrodynamics, which assume that the material is a continuum and does not take into account the material structure. MCA considers a material as an ensemble of bonded particles. Breaking of inter-particle bonds and formation of new bonds enables simulation of crack nucleation and healing, as well as mass mixing and *** paper consists of two main parts. In the first part, the simulations in 2 D statements are performed to study the dynamics of friction stir welding of duralumin plates and influence of different welding regimes on the features of the material stirring and temperature distribution in the forming welded joints. It is shown that the ratio of the rotational speed to the advancing velocity of the tool has a dramatic effect on the joint quality. A suitable choice of these parameters combined with additional ultrasonic impact could considerably reduce the number of pores and microcracks in the weld without significa

关键词： Friction stir welding Plastic flow Deformation mechanisms Simulation Particle method