检索结果-南通市图书馆

Effects of Current stressing on shear Properties of sn-3.8Ag-0.7Cu s.l.er Joints

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2010年第8期26卷 737-742页

作者： X.J. wang q.l. zeng q.s. Zhu Z.G. wang J.K. shang shenyang National laboratory for Materials science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 USA

Effects of electromigration on microstructure, shear strength, and fracture behavior of s.l.er joints were investigated by single-ball shear samples of eutectic sn-3.8Ag-0.7Cu （sAC） joined by Cu plates at two sides. The electromigration tests were conducted at a current density of about 1.1×10^3 A/cm2 and a working temperature of about 83℃. The res.l.s showed that the shear strength and flow stress decreased greatly after current stressing. such a decrease was associated with no significant loss of the fracture strain at short electromigration but a great reduction in the fracture strain after long-term current stressing. The variation of the fracture strain with the electromigration time was shown to res.l. from the shift of the fracture surface from the center of the s.l.er towards the intermetallic compound （IMC） interface at the cathode.

关键词： strength fracture strain Voids s.l.er

Merging bound states in the continuum in an open acoustic resonator

在线全文

学校读者我要写书评

暂无评论

science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 124-131页

作者： lujun Huang Bin Jia Artem s.Pilipchuk sibo Huang Chen shen Almas f.sadreev Yong li Andrey E.Miroshnichenko school of Physics and Electronic sciences East China Normal University Institute of Acoustics Tongji University l.V.Kirensky Institute of Physics Department of Mechanical Engineering Rowan University school of Engineering and Technology University of New South Wales at Canberra

Bound states in the continuum （BICs） are perfectly localized resonances despite embedding in the continuum ***,an is.l.ted BIC is very sensitive to the structure ***,we report merging acoustic BICs in a single open resonator,robust against the structure *** find that both symmetry-protected BIC and friedrich-Wintgen BIC are sustained in a single coupled waveguide-resonator *** varying the height and length of the resonator,these two BICs move toward each other and merge into a single one at a critical *** to an individual BIC,the merged BIC is robust against fabrication error because its q-factor is proportional to Δl-4,whereΔl embodies the structure *** essence of this extraordinary phenomenon is perfectly explained by the two-and three-level approximations of the effective nonHermitian ***,we present direct experimental demonstrations of the moving and merging of BICs in a coupled 3D waveguide-resonator,which are evidenced by the vanishing of the linewidth of fano resonance in the transmission *** res.l.s may find exciting applications in designing high-quality acoustic sources,sensors and filters.

关键词： acoustic resonances bound state in the continuum high-q resonances

EXPERIMENTAl REsEARCH AND NUMERICAl sIMUlATION Of lAsER sHOCK fORMING Of TA2 TITANIUM sHEET

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2006年第5期19卷 347-354页

作者： f. wang Z. q. Yao J. Hu q.l. Deng school of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200030 China

laser shock forming （Isf） was a new technique realized by applying an impulsive pressure generated by laser-induced shock wave on the surface of metal sheet. lsf of metal sheet was investigated with experiments and numerical simulation. The basic theories were introduced; the surface quality and deformation of the processed titanium sample （TA2） were examined; ABAqUs was used to simulate Isf and the central dis.l.cement of the shocked region was measured and compared with the simulation. Overlapped Isf treatment was experimentally carried out to produce groove and simulation. The res.l.s showed that the surface quality and the microstructure with single laser pulse had no remarkable change, and ablation was observed on the surface of the sample with overlapped pulses. The deformation observed in the numerical simulation agreeed with that observed in the experimental measurement quite well.

关键词： laser shock forming numerical simulation surface quality deformation

Reliability of.q.asi integrable and non-resonant Hamiltonian systems under fractional Gaussian noise excitation

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica sinica 2020年第4期36卷 902-909页

作者： q.f.lu W.q.Zhu M.l.Deng Department of Mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The reliability of.q.asi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is *** rather flat fGn power spectral density(PsD)in most part of frequency band,the fGn is innovatively regarded as a wide-band ***,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(sDEs).Reliability function and mean first passage time are obtained by s.l.ing the associated backward Kolmogorov equation and Pontryagin *** validity of the proposed procedure is tested by applying it to an example and comparing the numerical res.l.s with those from Monte Carlo simulation.

关键词： Reliability fkst passage time quasi integrable and non-resonant Hamiltonian systems fractional Gauss noise

Engineering complex systems applied to risk management in the mining industry

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

International Journal of Mining science and Technology 2017年第4期27卷 611-616页

作者： Domingues Maria s.q. Baptista Adelina l.f. Diogo Miguel Tato CERENA - Centre for Natural Resources and the Environment Faculty of Engineering University of Porto Porto 4200-465 Portugal ClEGI-Centre lusiada of Research and Development in Engineering and Industrial Management University Lusiada-North Vila Nova de Famalicao 4760-108 Portugal

Related to complexity, there is a wide diversity of concepts, ranging from ‘‘systemic" to ‘‘complex", implying a need for a unified terminology. Per different authors, the main drivers of complexity can be found in human behaviour and uncertainty. This complexity, structural or dynamic can be organizational, technological, or nested in their relationship. IsO international standard 31000:2009 definition of risk management ‘‘coordinated activities to direct and control an organization with regard to risk", when applied to economic sectors, industry, services, project, or activity, it requires the use of models or theories as guidelines. Therefore, as its basic elements comprehend human behaviour and/or uncertainty, risk management to be effective and adapted as much as possible to reality, must be operational within complex systems, as already demonstrated in different R&D environments. Risk management faces demanding challenges when approaching specific and endogenous needs, such as the mining sector. This paper presents a multivariable function analysis methodology approach based on complex system modelling and through real data corresponding to a risk management tool in the mining sector.

关键词： Risk Risk management Complex systems Mining Decision making

INVEsTIGATION Of BONDING IN NANO-siO_(2) BY si l_(2,3) X-RAY ABsORPTION NEAR-EDGE sTRUCTURE sPECTROsCOPY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2001年第6期14卷 473-478页

作者： Z.Y. Wu, K. Ibrahim, G. li, J. Zhang, f.q. liu, M.I Abbas, R. Hu, H.J. qian and f.q. Tang ( Beijing synchrotron Radiation facility, Institute of High Energy Physics, The Chinese Academy of sciences, Beijing 100039, China) ( laboratori Nazionali di frascat Inst. of High Energy Phys. Chinese Acad. of Sci. Beijing 100039 China

The si l2,3 X-ray absorption near-edge structure (XANEs) can be used to probe thelocal structure around si and derive electronic information of the unoccupied s- andd-like partial density of states in nano-size siO2. We present si l2,3-edge for threedifferent size s.l.cates acquired by total electron yield (TEY) at the photoemission sta-tion of Beijing synchrotron Radiation facility (BsRf). The si l2,3-edge spectra areinterpreted based on ab initio full multiple-scattering (Ms) calculation. The si l2.3-edge of nano-size materials has XANEs similar to that of a-quartz. The similaritiesbetween the si l2.3-edge shapes attest to a common molecular-orbital picture of theirsi-O bonding and the same coordination state. However, a considerable broadeningof si l2,3-edge XANEs spectra as decrease of particle size is also an indicative ofpolyhedral distortions.

关键词： multiple scattering calculation X-ray absorption nano particle electronic structure

Cutting Characteristics of Zr-Based Bulk Metallic Glass

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2015年第2期31卷 153-158页

作者： D.X.Han G.wang J.li K.C.Chan s.To f.f.Wu Y.l.Gao q.J.Zhai laboratory for Microstructures Shanghai University Department of Industrial and system Engineering The Hong Kong Polytechnic University

Cutting behavior exerts a considerable influence on the fabrication of bulk metallic glass(BMG) components. In this study,the influences of machining parameters(i.e.,depth of cutting,feed rate,and spindle rate) on the turned surface of a Zr-based BMG after observing the 3D morphologies of this surface were *** res.l.s showed that the influence of the spindle rate on the surface morphologies is more substantial as compared to the depth of cutting and the feed rate. Nanoscratch tests were conducted to further characterize the separation mechanism of the chips,which revealed that the chips are torn off the surface of a BMG because of inhomogeneous.l.calized maximum shear stress.

关键词： Bulk metallic glass Ultra-precision machining surf

Investigation of protein-styrene oxide adducts as a molecular biomarker of human exposed to styrene

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2001年第4期13卷 391-397页

作者： liu, s.-f. fang, q.-M. Jin, Z.-l. Rappaport, M.s. Res. Cntr. Eco-Environmental sci. Chinese Academy of Sciences Beijing 100085 China

Hemoglobin-styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein-styrene oxide adducts in different biological samples with modified Raney-Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro: rat blood reacted with styrene or styrene oxide in vivo: vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose-response relationship between reacting dose of styrene oxide or styrene and amount of protein-styrene oxide adducts in both in vitro and in vivo experiments. for human samples, a dose-response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.

关键词： Blood Drug dosage Glass fibers Hemoglobin Manufacture Oxides Proteins styrene

EffECT Of Ar PREssURE ON sTRUCTURAl AND ElECTRICAl PROPERTIEs Of Cu fIlMs DEPOsITED ON GlAss BY DC MAGNETRON sPUTTERING

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2002年第1期15卷 39-44页

作者： P. Wu f.P. wang l.q. Pan Y. Tian H. qiu Department of Physics University of Science and Technology Beijing Beijing 100083China Beijing Keda-Tianyu Microelectronic Material Technology Development Co. ltd. Beijing 100083 China

Cu films with thickness of 630-1300nm were deposited on glass substrates without heating by DC magnetron sputtering in pure Ar gas. Ar pressure was controlled to 0.5, 1.0 and 1.5Pa respectively. The target voltage was fixed at 500V but the target current increased from 200 to 1150mA with Ar pressure increasing. X-ray diffraction, scanning electron microscopy and atomic force microscopy were used to observe the structural characterization of the films. The resistivity of the films was measured using four-point probe technique. At all the Ar pressures, the Cu films have mixture crystalline orientations of [111], [200] and [220] in the direction of the film growth. The film deposited at lower pressure shows more [111] orientation while that deposited at higher pressure has more [220] orientation. The amount of larger grains in the film prepared at 0.5Pa Ar pressure is slightly less than that prepared at 1.0Pa and 1.5Pa Ar pressures. The resistivities of the films prepared at three different Ar pressures represent few differences, about 3-4 times of that of bulk material. Besides the deposition rate increases with Ar pressure because of the increase in target current. The contribution of the bombardment of energetic reflected Argon atoms to these phenomena is discussed.

关键词： Cu film DC magnetron sputtering deposition Ar pressure structure reststivity