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聚晶金刚石钻头切削齿切削岩块过程的有限元模拟

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石油勘探与开发 2015年第6期42卷 812-816页

作者： Pryhorovska T o Chaplinskiy s s Kudriavtsev i o ivano-Frankivsk National Technical University of oil and Gas

建立了聚晶金刚石(PDC)钻头切削齿切削岩石过程的有限元模型,模拟了不同形状切削齿不同切削深度下的线性和圆弧切削过程。模拟前确定了切削齿的空间形态、切削速度、切削深度、材料的流变模型、摩擦模型等。模拟结果表明:线性和圆弧切... 详细信息

建立了聚晶金刚石(PDC)钻头切削齿切削岩石过程的有限元模型,模拟了不同形状切削齿不同切削深度下的线性和圆弧切削过程。模拟前确定了切削齿的空间形态、切削速度、切削深度、材料的流变模型、摩擦模型等。模拟结果表明:线性和圆弧切削过程没有本质区别;各类切削齿的切削力波动均为振荡和不均匀的,不存在周期性;采用同一切削齿时不同切削深度下的切削力波动没有类似规律,但切削深度增加会引起波动幅度增大;切削深度为0.5 mm和1.0 mm时,切削参数保持稳定后平均切削力减小,而切削深度为2.0 mm时,进入稳定切削区后平均切削力并未减小;使用球形齿和圆锥形齿时切削力较小,而使用锥形齿、斜角形齿和平板形齿时切削力较大;采用平板形齿时切削力波动图上单位时间内峰数最少,采用球形齿时最多。

关键词： PDC钻头切削齿切削过程切削力有限元模拟

B3Y-FETAL effective interaction in the folding analysis of elastic scattering of ^(16)o+^(16)o

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Nuclear science and Techniques 2021年第8期32卷 34-47页

作者： i.ochala J.o.Fiase Department of Physics Kogi State UniversityP.M.B 1008 AnyigbaNigeria Department of Physics Benue State UniversityMakurdiNigeria

in this paper,a new M3Y-type effective nucleon–nucleon interaction,derived based on the lowest order constrained variational approach(LoCV)and termed B3Y-Fetal,has been used in DDM3Y1,BDM3Y1,BDM3Y2,and BDM3Y3 density-dependent versions in a heavy ion(Hi)optical potential based on four types of a real folded potential and a phenomenological Woods–saxon imaginary potential to study the elastic scattering of the^(16)o+^(16)o nuclear system within the framework of the optical model(oM)by computing the associated differential cross sections at various incident *** results of the folding analyses have shown the DDB3Y1-Fetal and BDB3Y1-Fetal,out of the four folded potentials,give a reasonably better description of the elastic data of the nuclear *** best-fit folded potentials are followed,in performance,by the BDB3Y2-Fetal,with the BDB3Y3-Fetal potential coming *** performance trend was also demonstrated by the optical potentials based on the M3Y-Reid ***,the best-fit folded potentials,renormalized by a factor NRof approximately 0.9,have been shown to reproduce the energy dependence of the real optical potential for^(16)o scattering found in previous optical model analyses creditably *** excellent agreement with previous works,they have also been identified in this work to belong to the family of deep refractive potentials because they have been able to reproduce and consistently describe the evolution of Airylike structures,at large scattering angles,observed in the^(16)o scattering data at different ***,a comparison of the performances of B3Y-Fetal and M3Y-Reid effective interactions undertaken in this work has shown impressive agreement between them.

关键词： B3Y-Fetal Folding analysis Elastic scattering optical model incident energies

structure and Properties of Nanostructured Vacuum-Deposited Foils of invar Fe–(35–38 wt%)Ni Alloys

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Journal of Materials science & Technology 2015年第11期31卷 1079-1086页

作者： V.M.Nadutov A.i.Ustinov s.A.Demchenkov Ye.o.svystunov V.s.skorodzievski G.V.Kurdyumov institute for Metal Physics of National Academy of sciences of Ukraine E.o.Paton Electric Welding institute of National Academy of sciences of Ukraine

The process of electron beam vacuum deposition of the Fe-（35-38 wt%）Ni alloys at substrate temperatures Ts from 300 to700 ℃ were used to produce vacuum-deposited foils with the FCC structure, differing by the size of characteristic microstructural elements （grains and subgrains）. it was shown that refinement of foil microstructural elements to nanoscale is accompanied by their microhardness increase up to 4-5 GPa. The change of the thermal expansion coefficient （TEC） of the nanostructured （Ns） foil of the Fe-35.1Ni alloy within the temperature range from -50 to 150 ℃ has some deviation from that observed for cast invar alloy of the same composition. it has been found that the main factors affecting the peculiarities of thermal expansion of the Ns foil can be related to the presence of small fraction of BCC- phase in them, high level of crystalline lattice microstrains and inhomogeneous magnetic order in FCC- phase. it was shown that as a result of additional thermal treatment of Ns foils their invar properties become similar to that observed for cast invar alloy but mechanical properties remain on the same level.

关键词： Fe-Ni alloys Electron beam physical vapor deposition (EBPVD) Nanostructured materials Hardness Thermal expansion Mossbauer spectroscopy

Negative Pion induced Fission with Heavy Target Nuclei

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Chinese Physics Letters 2011年第1期28卷 58-61页

作者： o. sher Mukhtar A. Rana s. Manzoor M. i. shahzad Physics Division PINSTECH P.O. Nilore Islamabad Pakistan

We investigate fission induced by negative pions in copper and bismuth targets using CR-39 dielectric track detectors. The target-detector assemblies in 4π-geometric configuration were exposed at the AGs facility of Brookhaven National Laboratory, UsA. The exposed detectors were chemically etched under appropriate etching conditions and scanned to collect data in the form of fission fragments tracks produced as a result of interaction of pions with the target nuclei. Using the track counts, the experimental fission cross sections for copper and bismuth have been measured at energies of 500, 672, 1068 and 1665 MeV and compared with the calculation using the Cascade-Exciton Model code （CEM95）. The values of fission probability based on experimental fission cross-sections have been compared with the theoretically calculated values of fission probabilities obtained using the CEM95 code. Good agreement is observed between the measured and computed results.

关键词： Nuclear physics

Understanding activity of butyrate at a cellular level

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Neural Regeneration Research 2025年第8期20卷 2323-2324页

作者： Prapti Chakraborty Angela s.Laird Macquarie University Motor Neuron Disease Research Centre Macquarie Medical SchoolFaculty of MedicineHealth and Human SciencesMacquarie UniversitySydneyAustralia

Butyrate is a short-chain fatty acid of four carbons in length that is a by-product produced by the microbial fermentation of dietary fiber and undigested carbohydrates within the *** the years,butyrate has attracted ... 详细信息

关键词： carbons butyrate fiber

Microglial dysfunction and genetic risk for neurodegenerative disease

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Neural Regeneration Research 2025年第5期20卷 1401-1402页

作者： Debra s.MacDonald Jay Penney Department of Biomedical sciences AVCUniversity of Prince Edward IslandCharlottetownPECanada

Neurodegenerative disorders such as Alzheimer's and Parkinson's diseases a re increasing in prevalence as world populations *** tremendous progress has been made,our understanding of the mechanisms that underlie the development of these diseases remains far from com *** troubling,despite the growing emotional and financial toll being to ken by neurodegenerative disorders,existing treatment options are limited almost exclusively to those that help manage symptoms but that lack the ability to alter the progression of the disease(Liu et al.,2022).

关键词： degenerative diseases

Cross-sections of photonuclear reactions ^(65)Cu(γ, n)^(64)Cu and ^(63)Cu(γ, xn)^(63−x)Cu in the energy range E_(γmax) = 35–94 MeV

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Chinese Physics C 2022年第12期46卷 208-216页

作者： o.s.Deiev i.s.Timchenko s.M.olejnik s.M.Potin V.A.Kushnir V.V.Mytrochenko s.A.Perezhogin B.i.shramenko National science Center“Kharkov institute of Physics and Technology” 1Akademichna St.61108KharkivUkraine

The flux-averaged cross-sectionsfor the reactions^(65)Cu(γ,n)^(64)Cu,^(63)Cu(γ,n)^(62)Cu,^(63)Cu(γ,2n)^(61)Cu,and^(63)Cu(γ,3n)^(60)Cu have been measured within the bremsstrahlung end-point energy E_(γmax)range of 35–94 *** experiments were performed with the electron beam from the NsC KiPT linear accelerator LUE-40 with the use of the activation and off-lineγ-ray spectrometric *** calculation of the flux-average cross-sections_(th)was conducted using the cross-sectionσ(E)values from the TALYs1.95 code,run with default *** is shown that the experimental average cross-sections for the reactions^(65)Cu(γ,n)^(64)Cu,^(63)Cu(γ,n)^(62)Cu,and^(63)Cu(γ,2n)^(61)Cu are systematically higher than the theoretical estimates based on the TALYs1.95 *** obtaineds supplement the data of different laboratories for the(γ,n)and(γ,2n)reactions of^(63)Cu and^(65)*** the reaction^(63)Cu(γ,3n)^(60)Cu,the values ofwere measured for the first time.

关键词： ^(63)Cu ^(65)Cu photonuclear reactions flux-averaged cross-section bremsstrahlung end-point energies of 35-94 MeV activation and off-lineγ-ray spectrometric techniques TALYs1.95 GEANT4

in-situ formation characteristic, tribological characterization and anti-corrosion properties of quaternary composites films

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Transactions of Nonferrous Metals society of China 2014年第10期24卷 3170-3180页

作者： ojo sunday isaac fayomi Abimbola Patricia idowu PoPooLA Department of Chemical Metallurgical and Materials EngineeringTshwane University of TechnologyP.M.B. X680 Pretoria South Africa

improvements of wear and corrosion properties are essential characteristic in engineering application. A study was made on the structure, electro-oxidation and properties of fabricated Zn-Al-sno 2-Ti o2（Zn-Al-sn-Ti） thin films using electrodeposition technique from chloride bath. The microstructural studies were performed by scanning electron microscopy with attached energy dispersive spectrometer（sEM-EDs）, optical microscopy（oPM） and X-ray diffractogram（XRD）. The electrochemical oxidation and erosion behavior in 3.65% Na Cl medium were studied by potentiodynamic polarization technique and characterized by atomic force microscopy（AFM）. The hardness and wear behavior of the electrodeposited film were performed by high diamond dura scan microhardness tester and CERT UMT-2 reciprocating sliding machine. it was found that a successful co-deposition of composite and particle were attained. Homogeneous imbedded grain structure distribution and fine refinement of crystal with improved micromechanical behavior was achieved. The corrosion resistance, hardness and wear stability resistance of the fabricated quaternary films improved significantly in all varied process parameter.

关键词： co-deposition microstructural evolution anti-corrosion property composite materials

Ferromagnetic Antiresonance and Giant Microwave Magneto-impedance in Polycrystalline La0.49sr0.51Mno3

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Chinese Physics Letters 2008年第3期25卷 1124-1127页

作者：柳文军舒启清 s. M. BHAGAT i. o. TRoYANCHUK College of Materials science and Engineering Shenzhen University Shenzhen 518060 shenzhen Key Laboratory of special Functional Materials Shenzhen 518060 Department of Physics University of Maryland College Park Maryland 20742-4111 USA institute of solid state and semiconductor Physics National Academy of Sciences of Belarus P. Brovki Street 17 Minsk 220072 Belarus

The ferromagnetic antiresonance （FMAR） phenomenon, i.e., the minimum of the microwave absorption, in polycrystalline La0.49sr0.51Mno3 is observed near Curie temperature TC = 282 K. Temperature-dependences of magnetization μ0M are obtained from the FMAR. The results show that as μ0H = 0, by fitting the scaling law M ∝ （TC -T）^β to temperature-dependences of μ0M at the different microwave frequencies, it yields TC=281.2 K and β = 0.47. However, temperature-dependences of μ0M under different μ0H are not in agreement with the scaling law. Due to FMAR, about 40% giant microwave magneto-impedance at 11.9 GHz can occur under a low field μ0H = 0.03 T.

关键词： MAGNEToREsisTANCE MANGANiTEs LA0.7sR0.3MNo3