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Quantum correlations and optical effects in a quantum-well cavity with a second-order nonlinearity

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Communications in Theoretical Physics 2021年第11期73卷 93-101页

作者： h Jabri higher Institute of Biotechnology of Beja University of JendoubaBeja 9000.Tunisia

In this paper,we investigate the photon correlations and the statistical properties of light produced by an optical cavity with an embedded quantum well interacting with squeezed *** show that the squeezed source substantially improves the intensity of the emitted light and generates a narrowing and a duplication of the spectrum *** a strong dependence on frequency detuning,the cavity produces considerably squeezed radiation,and perfect squeezing is predicted for weak light–matter ***,the system under consideration presents a bunching effect of the transmitted radiation resulting from weak pumping of the coherent *** results obtained may have potential applications in the fields of very accurate measurement and quantum computing.

关键词： quantum-well cavity second-order nonlinearity quantum fluctuations nonclassical effects

Calculation of the Specific heats for the Ⅱ—Ⅲ and Ⅱ—Ⅳ Phase transitions in Nh4I

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Chinese Physics Letters 2003年第1期20卷 35-38页

作者： h.Yurtseven h.Kaya Departmentofphysics IstanbulTechnicalUniversityMaslakIstanbulTurkey

This study gives our calculation for the specific heats CVI due to an Ising model using the observed CP data for the II-III and II-IV phase transitions in Nh4I. By fitting to the CP data we determine the values of the critical exponent for the pressure of 0.14 GPa (II-III phase transition) and for the pressures of 0.75, 1.35 and 1.97 GPa (II-IV phase transition) in Nh4I. Our exponent values are close to the predicted values of the specific heat in a three-dimensional Ising model. Our calculated CVI are in good agreement with the experimental CP for Nh4I in most cases.

关键词： Specific heat

Mechanical and microstructural characterization of Al7075/SiC nanocomposites fabricated by dynamic compaction

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International Journal of Minerals,Metallurgy and Materials 2014年第3期21卷 295-303页

作者： A.Atrian G.h.Majzoobi M.h.Enayati h.Bakhtiari Mechanical Engineering Department Bu-Ali Sina University Department of Materials Engineering Isfahan University of Technology

This paper describes the synthesis of Al7075 metal matrix composites reinforced with SiC, and the characterization of their microstructure and mechanical behavior. The mechanically milled Al7075 micron-sized powder and SiC nanoparticles are dynamically compacted using a drop hammer device. This compaction is performed at different temperatures and for various volume fractions of SiC nanoparticles. The relative density is directly related to the compaction temperature rise and indirectly related to the content of SiC nanoparticle reinforcement, respectively. Furthermore, increasing the amount of SiC nanoparticles improves the strength, stiffness, and hardness of the compacted specimens. The increase in hardness and strength may be attributed to the inherent hardness of the nanoparticles, and other phenomena such as thermal mismatch and crack shielding. Nevertheless, clustering of the nanoparticles at aluminum particle boundaries make these regions become a source of concentrated stress, which reduces the load carrying capacity of the compacted nanocomposite.

关键词： nanocomposites metallic matrix composites silicon carbide nanoparticles compaction

Solid-State Interfacial Reaction between Eutectic Au-Ge Solder and Cu/Ni(P)/Au Metalized Ceramic Substrate and Its Suppression

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Journal of Materials Science & Technology 2015年第5期31卷 445-452页

作者： F.Q.Lang h.Yamaguchi h.Nakagawa h.Sato Advanced Power Electronics Research Center(ADPERC) National Institute of Advanced Industrial Science and Technology(AIST).Central 21-1-1UmezonoTsukubaIbaraki 305-8568.Japan

Eutectic Au-12 Ge solder was employed to bond the SiC power devices to a Si3N4/Cu/Ni（P）/Au multilayered *** high-temperature reliability of the bond was investigated in detail at 200,250,300 and 330 ℃,*** and Ni5Ge3intermetallic compounds（IMCs） were identified at the Au-12Ge/Ni（P） interface by micro X-ray diffraction（μXRD） and scanning electron microscopy（SEM）equipped with energy dispersive X-ray analysis（EDX）.The growth of the Ni-Ge IMCs was dominated by Ni5Ge3layer,which formed at the Ni5Ge3/NiGe interface by outward diffusion of Ni from the Ni（P） *** activation energy of the total Ni-Ge IMCs growth was 66 kJ/*** shear strength of the bond was tested at both 25 ℃ and the aging temperatures,*** shear strength decreased slightly after aging at 200 and 250 ℃.The shear strength tested at 250 ℃ was 46 MPa after aging at 250 ℃ for 3000 *** shear strength aged at 300 and 330 ℃ rapidly decreased with aging time due to the rapid growth of the *** slow down the interfacial reaction between the high temperature solder and the Ni（P）layer,an approximately 200 nm-thick Ta/TaN/Ta new diffusion barrier（DB） was deposited on the *** by transmission electron microscopy（TEM） equipped with EDX,reveals that the Ta/TaN/Ta DB was bonded well to the Ni（P） layer and the *** temperature storage test at 330 ℃ for1500 h reveals that the bond of the SiC devices maintained its high shear strength of approximately56 MPa without *** new DB effectively suppressed the interfacial reaction between the Au-12 Ge solder and the Ni（P） layer of the substrate.

关键词： high-temperature solder Interfacial reaction Activ

A modified averaging scheme with application to the secondary hopf bifurcation of a delayed van der Pol oscillator

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Acta Mechanica Sinica 2008年第4期24卷 449-454页

作者： Z.h.Wang h.Y.hu Institute of Sciences PLA University of Science and Technology Nanjing 211101 China Institute of Vibration Engineering Research Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

In this paper, a modified averaging scheme is presented for a class of time-delayed vibration systems with slow variables. The new scheme is a combination of the averaging techniques proposed by hale and by Lehman and Weibel, respectively. The averaged equation obtained from the modified scheme is simple enough but it retains the required information for the local nonlinear dynamics around an equilibrium. As an application of the present method, the delay value for which a secondary hopf bifurcation occurs is successfully located for a delayed van der Pol oscillator.

关键词： Time delay ·Secondary hopf bifurcation·The averaging technique van der Pol oscillator

Numerical Solution of the Asymmetric Water Impact of A Wedge in Three Degrees of Freedom

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China Ocean Engineering 2013年第3期27卷 313-322页

作者： h. Ghazizade-Ahsaee A. h. Nikseresht Faculty of Mechanical & Aerospace Engineering Shiraz University of Technology

Impact problems associated with water entry have important applications in various aspects of naval architecture and ocean engineering. Estimation of hydrodynamic impact forces especially during the first instances after the impact is very important and is of interest. Since the estimation of hydrodynamic impact load plays an important role in safe design and also in evaluation of structural weight and costs, it is better to use a reliable and accurate prediction method instead of a simple estimation resulted by analyzing methods. In landing of flying boats, some phenomena such as weather conditions and strong winds can cause asymmetric instead of symmetric descent. In this paper, a numerical simulation of the asymmetric impact of a wedge, as the step of a flying boat, considering dynamic equations in two-phase flow is taken into account. The dynamic motion of the wedge in two-phase flow is solved based on finite volume method with volume of fluid （VOF） scheme considering dynamic equations. Then the effects of different angles of impact and water depth on the velocity change and slamming forces in an asymmetric impact are investigated. The comparison between the simulation results and experimental data verifies the accuracy of the method applied in the present study.

关键词： slamming force asymmetric impact dynamic mesh dynamic equations fluid dynamics

GLOBAL OPTIMIZATION OF ThE DIFFERENCE OF TWO INCREASING PLUS-CONVEX-ALONG-RAYS FUNCTIONS

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Acta Mathematica Scientia 2020年第6期40卷 1849-1873页

作者： h.ShAhRIARIPOUR h.MOhEBI Department of Mathematics Graduate University of Advanced TechnologyKermanIran Department of Mathematics and Mahani Mathematical Research Center Shahid Bahonar University of KermanP.O.Box:76169133Postal Code:***KermanIran

The theory of increasing and convex-along-rays(ICAR)functions defined on a convex cone in a real locally convex topological vector space X was already well *** this paper,we first examine abstract convexity of increasing plus-convex-along-rays(IPCAR)functions defined on a real normed linear space *** also study,for this class of functions,some concepts of abstract convexity,such as support sets and ***,as an application,we characterize the maximal elements of the support set of strictly IPCAR functions and give optimality conditions for the global minimum of the difference between two IPCAR functions.

关键词： increasing plus-convex-along-rays function support set maximal element global minimum DC-function

Numerical simulation and experimental study for rheo-forged component using direct and indirect die system

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1799-1804页

作者： h.h.KIM C.G.KANG Precision Manufacturing Systems Division Pusan National University School of Mechanical Engineering Pusan National University

Sand casting and die casting processes have been used widely for complex automotive products such as knuckle, arm, ***, a part fabricated by casting has limited strength due to manufacturing defects such as the dendrite structure, segregation and *** an attempt to offer a solution to these problems, forging has been used as an alternative ***, the forging process provides limited formability for complex shape ***-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming *** order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of molten *** results of an A356 aluminum alloy sample, which are obtained by experiment and by simulation using DEFORM 3D, are present.

关键词： rheo-forging A356 alloy formability forming defects

Shortening the Duration of heat Treatment in the Lower Bainitic Range

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材料热处理学报 2004年第5期25卷 555-560页

作者： h. Vetters h.-W. Zoch Foundation Institute for Materials Science Bremen GermanyFoundation Institute for Materials Science Bremen Germany

In many cases an isothermal treatment of throughhardening bearing grades in the lower bainitic range allows to adjust the mechanical properties of machine components to the later application, similar to those of martensitic hardening. The achieved microstructure contains only a negligible amount of retained austenite, so a dimensional change of components during application can be reduced. One disadvantage of the isothermal bainitic treatment in salt bath is that the duration of the treatment is much longer than that of the martensitic hardening and this causes higher costs. Therefore it would be desirable to be able to shorten the transformation duration in the lower bainitic range. The aim of the present work is to determine the parameters, by which the process could be greatly shortened in comparison with the conventional transformation process in the lower bainitic range. Therefore the bainitic transformation behavior of the steel 100 Cr6 (SAE 52100) and the relevant influence factors were investigated by means of dilatometry, in which the heat treatments were carried out with different process variants including pre-quenching or post-quenching. The amount of retained austenite in the microstructure and the hardness of the steel after the shortened heat treatments were measured. Finally the possibility to use these processes in industrial production is discussed.

关键词：贝氏体轴承钢膨胀测定法热处理