检索结果-南通市图书馆

High pressure CMP with low stress polishing

在线全文

学校读者我要写书评

暂无评论

金刚石与磨料磨具工程 2008年第S1期28卷 119-125,129页

作者： Hiroshi Ishizuka Sung James C. Marehito aoki Haedo Jeong Sung Michael Tomei Die International Co. Ltd.Akasaka Tokyu Bldg.11F14-3 Nagatacho 2-ChomeChiyoda-ku KINIK Company 64Chung-San Rd.Ying-Kuo National Taiwan University National Taipei University of Technology Tomei Diamond Co. Ltd.Oyama Plant4-5-1 JyotoOyamaTochigi 323-0807Japan. G&P Technology Inc.South Korea. Advanced Diamond Solutions Inc.351 King Street Suite 813San FranciscoCA 94158U.S.A.

Low stress polishing is required for the manufacture of advanced integrated circuits(IC) with node sizes of 45 nm and ***,the CMP community achieved the low stress by reducing the down force that press the wafer against a rotating *** reduced down force also decrease the removal rate of the wafer. As a result,the productivity *** order to cope with this problem,an electrical potential is applied to the copper layer during polishing,in this case,the chemical oxidation is accelearated and hence the removal rate. Alternatively,the rotating pad must be softened to minimize the defects of wafers caused by CMP. In this research,we report a simpler solution to achieve low stress polishing without investing in new equipment and in developing new pad *** conventional CMP is proceeded by dressing the pad with a PCD dresser that can form 10×more asperities on the pad *** fluffy surface can then polish delicate IC without using the brutal *** a result,the removal rate of wafers can be maintained without causing defectivity on the IC layer.

关键词： IC CMP eCMP PCD dresser Moore’s Law 32nm node

Model of homogenisation for analysing the effect of micrometre pore sizes on the elastic moduli of porous materials

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2019年第5期35卷 1060-1066页

作者： A.f.fedotov Department of Mechanics Samara State Technical UniversitySamara 443100Russian Federation

A homogenisation model for analysing the effect of micrometre pore sizes on the engineering moduli of elasticity of porous materials was *** the proposed model,the engineering coefficients of localization of total strains(LTS coefficients)are considered instead of the classical strain localization *** a pore,these coefficients represent the ratio of the sum of the strains in the volume of the pore to the sum of the strains in the volume of the porous *** estimate the elastic moduli of a material with an arbitrary pore size,it is sufficient to have information about the elastic moduli and the LTS coefficient of a material with one basic pore ***,in Eshelby's model of equivalent inclusion,a transition to LTS coefficient for material with arbitrary pore size is achieved,and its elasticity moduli are *** results for Young's modulus of porous titanium,with different sizes of spherical pores,completely conform with the experimental *** have obtained a model theoretic estimate of the upper bounds of Young's modulus of porous materials with infinitely small pore *** the spherical pores,the proposed assessment coincides with the upper limits of the Hashin-Shtrikman bounds.

关键词： Elastic moduli Porous material Pore sizes

Synchronization of two coupled pendula in absence of escapement

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

Applied Mathematics and Mechanics(English Edition) 2016年第12期37卷 1721-1738页

作者： f.TALAMUCCI DIMAI Dipartimento di Matematica e Informatica "Ulisse Dini"Università degli Studi di Firenze

A model of two oscillating pendula placed on a mobile support is studied. Once an overall scheme of equations, under general assumptions, is formulated via the Lagrangian equations of motion, the specific case of absence of escapement is examined. The mechanical model consists of two coupled pendula both oscillating on a moving board attached to a spring. The final result performs selection among the peculiar parameters of the physical process （the length, the ratio of masses, the friction and damping coefficients, and the stiffness of the spring）, providing a tendency to synchronization.

关键词： synchronization coupled pendula characteristic equation eigenvalue lo-calization

New approaches to vibrational spectroscopy of zeolite catalysts: a perspective

在线全文

学校读者我要写书评

暂无评论

frontiers of Chemical Science and Engineering 2024年第11期18卷 151-156页

作者： Russell f Howe Chemistry Department University of AberdeenAberdeen 999020UK

This perspective discusses three alternative techniques which complement conventional infrared spectroscopy for obtaining vibrational information about zeolite catalysts and adsorbed molecules:inelastic neutron scattering,infrared micro-spectroscopy,and two-dimensional infrared *** techniques are illustrated briefly and future prospects for their use discussed.

关键词： fTIR zeolites INS micro-spectroscopy 2D fTIR

Control and vibration analyses of a sandwich doubly curved micro-composite shell with honeycomb,truss,and corrugated cores based on the fourth-order shear deformation theory

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

Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1773-1790页

作者： f.SHIRDELAN M.MOHAMMADIMEHR f.BARGOZINI Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan 87317-53153Iran

Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive ***,the inability of controlling and regulating vibrations and destroying them afterward is a challenge to *** this paper,the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms.A five-layer sandwich doubly curved micro-composite shell,comprising two piezoelectric layers for the sensor and actuator,is modeled by the fourth-order shear deformation *** core(honeycomb,truss,and corrugated)is analyzed for the bearing of transverse shear *** results show that the honeycomb core has a greater effect on the *** the parameters related to the core and the weight percentage of graphene increase,the frequency *** uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency ***,without taking into account the piezoelectric layers,the third-order shear deformation theory(TSDT)and fourth-order shear deformation theory(fOSDT)align ***,when the piezoelectric layers are incorporated,these two theories diverge significantly,with the frequencies in the fOSDT being lower than those in the TSDT.

关键词： vibration and control doubly curved shell micro-composite honeycomb truss corrugate core

Electrical Properties of Li-doped P-type ZnO Ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2009年第3期25卷 314-318页

作者： A.H. Salama f.f. Hammad Physical Chemistry Department National Research Center Inorganic Chemistry Department National Research Center

Li-doped p-type ZnO ceramics were prepared by conventional methods according to the chemical formula Zn1-xLixO2 where x=0.5, 1.0, 1.5 and 2.0 mole fraction, respectively. The crystal structures of the prepared samples were studied by X-ray diffraction analysis. The dielectric properties （including dielectric constant ε′ and dielectric loss ε″） and dc-electrical conductivity [σ（Ω^-***^-1）] were investigated. The dielectric constant ε′ was sharply decreased at the low frequency range and independent on frequency at high frequency range. Otherwise, the dielectric loss ε″ varied with frequency and showed absorption peak located from 200 Hz to 4 kHz and moved to higher frequency as the concentration of Li＋ doped increased. It was found that dcelectrical conductivity logσ varied from -9 to -5 and the energy gap width were calculated by using Arrhenius equation. The p-type conductivity of Li-doped ZnO may be attributed to the formation of a Lizn-Lii donor complex, which is limited by reducing the amount of Lii.

关键词： P-type ZnO ceramics Dielectric constant Dielectric loss dc-conductivity

An old issue and a new challenge for nuclear reactor safety

在线全文

学校读者我要写书评

暂无评论

frontiers in Energy 2021年第4期15卷 854-859页

作者： f.D’AURIA University of Pisa DESTEC/GRNSPG–L.go L.Lazzarino 256100 PisaItaly

Nuclear reactor safety(NRS)and the branch accident analysis(AA)constitute proven technologies:these are based on,among the other things,long lasting research and operational experience in the area of water cooled nuclear reactors(WCNR).Large break loss of coolant accident(LBLOCA)has been,so far,the orienting scenario within AA and a basis for the design of *** incomplete vision for those technologies during the last few years is as follows:Progress in fundamentals was stagnant,namely in those countries where the WCNR were *** became evident,noticeably in relation to nuclear fuel under high *** estimate plus uncertainty(BEPU)techniques were perfected and available for *** and informatics systems were in extensive use and their impact in case of accident becomes more and more un-checked(however,quite irrelevant in case of LBLOCA).The time delay between technological discoveries and applications was becoming *** present paper deals with the LBLOCA that is inserted into the above *** conclusion is that regulations need suitable modification,rather than lowering the importance and the role of ***,strengths of emergency core cooling system(ECCS)and containment need a tight link.

关键词： large break loss of coolant accident(LBLOCA) nuclear reactor safety(NRS) licensing perspectives basis for design of water cooled nuclear reactors(WCNR)

Axial magnetic field effect in numerical analysis of high power Cherenkov free electron laser

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第6期28卷 176-183页

作者： f BazoubAND B Maraghechi Department of Physics Fasa UniversityPost code 74616-86131FasaIran Department of Physics Manhattanville CollegePurchaseNew York 10577USA

Cherenkov free electron laser(CfEL) is simulated numerically by using the single particle method to optimize the electron beam. The electron beam is assumed to be moving near the surface of a flat dielectric slab along a growing radiation. The set of coupled nonlinear differential equations of motion is solved to study the electron dynamics. for three sets of parameters, in high power CfEL, it is found that an axial magnetic field is always necessary to keep the electron beam in the interaction region and its optimal strength is reported for each case. At the injection point, the electron beam’s distance above the dielectric surface is kept at a minimum value so that the electrons neither hit the dielectric nor move away from it to the weaker radiation fields and out of the interaction region. The optimal electron beam radius and current are thereby calculated. This analysis is in agreement with two previous numerical studies for a cylindrical waveguide but is at odds with analytical treatments of a flat dielectric that does not use an axial magnetic field. This is backed by an interesting physical reasoning.

关键词： Cherenkov free electron laser axial magnetic field flat dielectric slab electron beam

Characterization of Phases in an As-cast Copper-Manganese-Aluminum Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2006年第6期22卷 779-784页

作者： J.Iqbal f.Hasan f.Ahmad Department of Metallurgical and Materials Engineering University of Engineering and TechnologyLahorePakistan

Copper-manganese-aluminum （CMA） alloys, containing small additions of fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast （CMA） alloy of nominal composition Cu-14%Mn-8%Al-3%fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The room temperature microstructure exhibited four different types of precipitates inside the α-grains： the ＇large＇ dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in fe and Mn and had an fcc structure, while the ＇small＇ dendritic-shaped particles and the globular precipitates were based on feaAI and had DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientation-relationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on fe3Al and had the DO3 structure.

关键词： Orientation relationship DO3 structure Intermetallic phases