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Properties of Co_2FeAl heusler Alloy Nano-particles Synthesized by Coprecipitation and Thermal Deoxidization Method

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Journal of Materials Science & Technology 2013年第3期29卷 245-248页

作者： J.h.Du Y.l.Zuo Z.Wang J.h.Ma l.Xi Key laboratory for Magnetism and Magnetic Materials of Ministry of Education Lanzhou University

Co2FeAl nanoparticles were synthesized by reducing the coprecipitated precursor of COCl2·6h2O, Fe（NO3）3·9h2O and AI2（SO4）3·18h2O under h2 atmosphere with various annealing temperatures and durations. X-ray diffraction and transmission electron microscopy were used to characterize the crystal structure and microstructure of Co2FeAl particles, respectively. The investigation indicates that the crystal structure of CO2FeAI particles tends to be B2 structure, in which atoms are partially ordered. The saturation magnetization and hyperfine field of CO2FeAI particles, which were measured under a vibrating sample magnetometer and a 57Fe Mossbauer spectroscope, are consistent with those of the bulk sample and thin films. Furthermore, the higher annealing temperature and the longer annealing time, the better crystallinity of CO2FeAI and more ordered arrangement of atoms will be. It turned out that the coprecipitation thermal deoxidization method could be an easy and high efficient way to obtain the half-metallic CO2FeAI nanoparticles.

关键词： heusler alloy Coprecipitation Magnetic property

Exact solution and dynamic buckling analysis of a beam-column system having the elliptic type loading

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Applied Mathematics and Mechanics(English Edition) 2010年第10期31卷 1317-1324页

作者： h.S.ARTEM l.AYDIN Department of Mechanical Engineering Izmir Institute of Technology

This paper presents a closed form solution to the dynamic stability problem of a beam-column system with hinged ends loaded by an axial periodically time-varying compressive force of an elliptic type,i.e.,a1cn 2（τ,k 2）＋a2sn 2（τ,k 2）＋a3dn 2（τ,k 2）.The solution to the governing equation is obtained in the form of Fourier sine *** resulting ordinary differential equation is solved *** the exact analytical solutions to the dynamic buckling problems is ***,the availability of exact solutions can provide adequate understanding for the physical characteristics of the *** this study,the frequency-response characteristics of the system,the effects of the static load,the driving forces,and the frequency ratio on the critical buckling load are also investigated.

关键词： dynamic buckling exact solution stability-instability Jacobi elliptic functions

Static spheroidization and its effect on superplasticity of fine lamellae in nugget of a friction stir welded Ti-6Al-4V joint

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Journal of Materials Science & Technology 2022年第24期119卷 1-10页

作者： C.l.Jia l.h.Wu P.Xue h.Zhang D.R.Ni B.l.Xiao Z.Y.Ma 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 Key laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The spheroidization of the lamellar structure can greatly contribute to the superplasticity of the nugget zone(NZ)of Ti alloy welds,which is the key to achieve the integral superplastic forming of welds for the fabrication of large-scale complex ***,the spheroidization process is complex and costly since it cannot be obtained generally,unless the lamellae suffers from a large *** this study,the static spheroidization was achieved for the fine lamellae structure in the nugget of a friction stir welded(FSW)Ti-6Al-4V joint,particularly by the annealing without any *** specialα/βinterface obeying a Burgers orientation relationship(BOR)after FSW was first time directly observed,whose effect on the spheroidization was discussed.A new static spheroidization mechanism with the gradual coalescence of the adjacent lamellae was discovered,which we named as“termination coalescence”.There was a slower coarsening rate in the lamellar structure than in the classical equiaxed one,due to the BOR in the lamellae,although both of them exhibited a volume diffusion character during ***,the similar superplasticity can be achieved for the base material and NZ after *** study can provide a new way to the spheroidization and a theoretical basis for the integral superplastic forming of welds during production.

关键词： Friction stir welding Titanium alloys Spheroidization mechanism Coalescence Superplasticity Static annealing

Colloidal(Gd0.98Nd0.02)2O3 nanothermometers operating in a cell culture medium within the first and second biological windows

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Journal of Rare Earths 2020年第5期38卷 483-491页

作者： M.l.Debasu h.Oliveira J.Rocha l.D.Carlos Department of Physics CICECO-Aveiro Institute of MaterilsUniversidade de Aveiro3810-193AveiroPortugal Department of Chemistry CICECO-Aveiro Institute of MaterialsUniversidade de Aveiro3810-193AveiroPortugal Department of Biology CESAMLaboratory of Biotechnology and CytomicsUniversidade de Aveiro3810-193AveiroPortugal

Non-contact,self-referenced and near-infrared luminescent nanothermometers have been recognized as emerging tools in the fields of nanomedicine and nanotechnology due to their great capability of precise temperature readout at the nanoscale and real-time deep-tissue ***,the development of multifunctional and biocompatible luminescent nanothermometers operating within the optically transparent biological windows with high thermal sensitivity(>2.0%/K)remains ***,we present(Gd0.98Nd0.02)2O3 nanothermometers operated effectively within the first and second biological windows upon continuous-wave laser diode excitation at 808 *** thermometric parameters are defined by the relative changes in the emission intensities originating from the two Stark components of the 4 F3/2 level(R2 and R1)to the 4 I9/2(900-1000 nm),4 I11/2(1035-1155 nm)and 4 I13/2(1300-1450 nm)*** thermo metric parameters are evaluated for colloidal samples in a cell culture medium and powder samples,and the highest thermal sensitivity(2.18%/K at 298 K)is attained for the former in the first biological window(both the excitation and emission in the 800-965 nm range).The repeatability and temperature uncertainty are 99%and 1.2 K,*** nanothermometers are biocompatible with human MNT-1 melanoma and haCaT cells for 24 h of exposure and nanoparticle concentration up to 0.400 mg/ml,showing their potential for applications in nanomedicine,e.g.,intracellular imaging and temperature mapping.

关键词： Gd2O3 Nd3^+-doped nanoparticles luminescent nanothermometry Thermal sensitivity Cytotoxicity of nanoparticles Rare earths

ANTIPERIODIC WAVElETS

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Journal of Computational Mathematics 1996年第1期14卷 32-39页

作者： h.l. Chen(Institute of Mathematics, Academia Sinica, Beijing) 中科院数学所北京

In this paper, we construct the orthogonal wavelet basis in the space of antiperiodic functions by appealing the spline methods. Differing from other results in papers([1,2,3,6,8]), here we derive the 3-scale equation, by using this equation we construct some basic functions, those functions can be used to construct different orthonormal basis in some spline function spaces.

关键词： Math ANTIPERIODIC WAVElETS Pro

A stable CS-FEM for the static and seismic stability of a single square tunnel in the soil where the shear strength increases linearly with depth

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1253-1265页

作者： h.C.Nguyen l.Nguyen-Son Department of Civil and Environmental Engineering Imperial College LondonLondonUK Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolUK Faculty of Civil Engineering Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityViet Nam

A numerical procedure using a stable cell-based smoothed finite element method(CS-FEM)is presented for estimation of stability of a square tunnel in the soil where the shear strength increases linearly with *** kinematically admissible displacement fields are approximated by uniform quadrilateral elements in conjunction with the strain smoothing technique,eliminating volumetric locking issues and the singularity associated with the MohreCoulomb ***,a rich set of simulations was performed to compute the static stability of a square tunnel with different geometries and soil *** presented results are in excellent agreement with the upper and lower bound solutions using the standard finite element method(FEM).The stability charts and tables are given for practical use in the tunnel design,along with a newly proposed formulation for predicting the undrained stability of a single square ***,the seismic stability number was computed using the present numerical *** results reveal that the seismic stability number reduces with an increasing value of the horizontal seismic acceleration(a_(h)),for both cases of the weightless soil and the soil with unit ***,the link between the static and seismic stability numbers is described using corrective factors that represent reductions in the tunnel stability due to seismic *** is shown from the numerical results that the corrective factor becomes larger as the unit weight of soil mass increases;however,the degree of the reduction in seismic stability number tends to reduce for the case of the homogeneous ***,this advanced numerical procedure is straightforward to extend to three-dimensional(3D)limit analysis and is readily applicable for the calculation of the stability of tunnels in highly anisotropic and heterogeneous soils which are often encountered in practice.

关键词： Tunnels Stability limit analysis Cell-based smoothed finite element method (CS-FEM) Second-order cone programming(SOCP)

STRAIN RATE SENSITIVITY OF UlTRAFINE-GRAINED Cu WITh NANOSIZED TWINS

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Acta Metallurgica Sinica(English letters) 2006年第5期19卷 313-318页

作者： l.X. liu X.h. Chen l. lu Shenyang National laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

An ultrafine-grained Cu sample with a high density of growth twins was synthesized by means of pulsed electrodeposition technique. The strain rate sensitivity of the Cu sample was measured by strain rate cycling tests under tension. The effects of grain size as well as twin density on the strength and strain rate sensitivity were discussed.

关键词： copper nanosized twin strain rate sensitivity deformation mechanism

Axonal regeneration and sprouting as a potential therapeutic target for nervous system disorders

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Neural Regeneration Research 2021年第10期16卷 1901-1910页

作者： Katherine l.Marshall Mohamed h.Farah Department of Neurology at Johns hopkins School of Medicine BaltimoreMDUSA

Nervous system disorders are prevalent health issues that will only continue to increase in frequency as the population ***-back axonopathy is a hallmark of many neurologic diseases and leads to axonal disconnection from their targets,which in turn leads to functional *** the course of many of neurologic diseases,axons can regenerate or sprout in an attempt to reconnect with the target and restore synapse *** amyotrophic lateral sclerosis(AlS),distal motor axons retract from neuromuscular junctions early in the disease-course before significant motor neuron *** is evidence of compensatory motor axon sprouting and reinnervation of neuromuscular junctions in AlS that is usually quickly overtaken by the disease *** drugs that enhance compensatory sprouting and encourage reinnervation may slow symptom progression and retain muscle function for a longer period of time in AlS and in other diseases that exhibit dying-back *** remain many outstanding questions as to the impact of distinct disease-causing mutations on axonal outgrowth and regeneration,especially in regards to motor neurons derived from patient induced pluripotent stem *** microfluidic chambers are powerful tools for studying the distal axons of human induced pluripotent stem cells-derived motor neurons,and have recently been used to demonstrate striking regeneration defects in human motor neurons harboring AlS disease-causing *** the human neuromuscular circuit with human induced pluripotent stem cells-derived motor neurons will be critical for developing drugs that enhance axonal regeneration,sprouting,and reinnervation of neuromuscular *** this review we will discuss compensatory axonal sprouting as a potential therapeutic target for AlS,and the use of compartmentalized microfluidic devices to find drugs that enhance regeneration and axonal sprouting of motor axons.

关键词： amyotrophic lateral sclerosis axonal regeneration dying-back axonopathy in vitro neuromuscular junction iPSC-derived motor neurons microfluidic device motor axon sprouting

Regional lymphadenectomy strongly recommended in T1b gallbladder cancer

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World Journal of Gastroenterology 2011年第38期17卷 4347-4348页

作者： Ulrich Klaus Fetzner Arnulf h hlscher Dirk l Stippel Department of General Visceral and Cancer SurgeryUniversity Hospital of Cologne

This article discusses the adequate treatment of early gallbladder cancer （Tla, Tlb） and is based on published studies extending over nearly 3 decades. Ran- domized studies and meta analyses comparing different surgical treatments do not exist. The literature shows that in up to 20% of patients lymph node metastasis are found in Tlb gallbladder cancer. Due to high malignancy with early angiolymphatic spread and resistance to chemotherapy and radiation on the one hand, and the relative low operative risk of extended cholecystectomy （cholecystectomy and regional lymphadenectomy） on the other hand, we believe that this procedure is mandatory in early gallbladder cancer.

关键词： Gallbladder cancer long-term survival lymphadenectomy Surgical treatment