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991.
By using the quantum teleportation protocol, Alice can send an unknown quantum state (e.g. the polarization of a single photon) to Bob without ever knowing about it. This paper discusses a quantum teleportation experiment in which nonlinear interactions are used for the Bell state measurement. Since the Bell state measurement is based on nonlinear interactions, all four Bell states can be distinguished. Therefore, teleportation of a polarization state can occur with certainty, in principle. Details of the theory and the experimental set-up are discussed.  相似文献   
992.
The ratcheting behaviour of Inconel 718 was investigated at 649 °C under uniaxial cyclic loading. Stress-control tests have been conducted at various combinations of stress amplitude and mean stress. The ratcheting strain at failure increases with increasing mean stress for a given stress amplitude and with decreasing stress amplitude for a given mean stress. Fatigue lives were correlated using three mean stress models: the Goodman equation, the Smith–Watson–Topper (SWT) parameter and the Walker parameter. It has been shown that the Goodman equation and the SWT parameter do not correlate life data, while the Walker parameter yields acceptable correlation. The SWT parameter was modified to incorporate the ratcheting effect. The new parameter is found to yield correlation similar to that of the Walker parameter.  相似文献   
993.
Cu-free and Cu-doped LSM system, La0·8Sr0·2Mn1???x Cu x O3???δ (x?=?0, 0·2), with perovskite structure were prepared using an EDTA combined citrate process and the effects of Cu ion at B-site were investigated. Electrical conductivity and polarization resistance of the Cu-doped LSM were 210 S·cm???1 at 750 °C, and 2·54 Ω · cm2 at 800 °C, respectively which were better than those of the Cu-free LSM. This indicated that the electrode performance of LSM was improved by the addition of Cu. The oxidation state of Mn ions increased with addition of Cu. The increase in the oxidation state of Mn ions was due to the formation of Mn4?+? ions and oxygen vacancies. The addition of Cu ions to LSM systems could lead to enhanced electrode performance for oxygen reduction reactions originating from the change in valence of Mn ions.  相似文献   
994.
3 Mol% of europium doped strontium aluminate (SrAl2O4:Eu2 + ) coatings on silicon substrates were prepared by electrostatic spray deposition method using a salted sol–gel derived solution as a starting material. As-deposited films at 100°C for 5 h were heated at 1100°C for 2 h under a reducing ambient atmosphere of 95%N2 + 5%H2. Nanocrystalline SrAl2O4 film was confirmed by surface morphological and crystallographic analyses. Monitored at 520 nm, the excitation spectrum showed a broad band from 300 ~ 500 nm and the emission intensity showed a maximum yellow peak intensity at 512 nm with a broad band from 460 ~ 610 nm.  相似文献   
995.
In this study, a particle trajectory analysis and charging measurements of triboelectrically charged silica and glassy carbon particles were conducted to investigate the effects of charging gas velocity and particle size on triboelectrical charging characteristics. A particle motion analysis system (PMAS) was used to measure charged particle motion information in the separation chamber with an applied uniform electric field, and the particle charging amount was calculated from the particle size and the electrostatic mobility was determined by the PMAS. The test system consisted of a particle generator, a spiral-type tribocharger made of a copper tube, and a particle motion analysis system to measure the particle size and velocity. The experiments were conducted with test particles of silica and glassy carbon and the average charging gas velocities of 6, 10, 15, 20 m/s to analyze the effect on particle charging. As a result, the silica and glassy carbon particles acquired negative and positive charges, respectively, due to the differences in the work functions, and the charging gas velocity effect on particle charge was approximately linear with an increasing velocity yielding a higher average particle charge and wider distribution.  相似文献   
996.
感应自发热重熔(ISHR)技术在电子互连的应用中具有明显的三维选择性加热和快速加热等优点.该方法能够很好地解决由于无铅钎料的应用引起的日益严重的诸多问题,如球栅阵列中各钎料球受热不均匀和芯片基板与钎料球同时受热等.为此,采用ISHR进行了无铅钎料Sn3.5Ag在Au/Ni/Cu焊盘上的重熔实验、高温老化实验以及凸台剪切实验.由实验结果可知钎料凸台可以提供足够的剪切强度.文中讨论了界面反应和金属间化合物的演化.在老化期间界面处生长了连续的Ni3Sn4金属间化合物层,同时在钎料体内部生成了分散的(Aux,Ni1-x)Sn4化合物.金属间化合物的生长速度与老化时间的平方根成正比。由此可以判断金属间化合物的生长是一种扩散控制过程.  相似文献   
997.
A continuous damage fracture model, which consists of a fracture criterion and a continuum damage constitutive law was proposed in this paper to calculate formability of sheet metal. In this model, an extension of the McClintock void growth model was selected as the fracture criterion to be incorporated with a coupled damage‐plasticity Gurson‐type constitutive law. Also, by introducing a Lode angle dependent parameter to define the loading asymmetry condition, the shear effect was phenomenologically taken into account. The proposed fracture model was implemented in user defined material subroutines in ABAQUS. The model was calibrated and correlated by the uniaxial tension, shear and notched specimens tests. Application of the fracture criterion for the Limit dome height tests was discussed and the simulation results were compared with the experimental data.  相似文献   
998.
Spherical indentation of ceramic coatings with metallic interlayer was performed by means of axisymmetric finite element analysis(FEA). Two typical ceramic coatings with relatively high and low elastic modulus deposited on aluminum alloy and carbon steel were considered. The fracture mechanics of the ceramic coatings mechanisms due to occurrence of surface ring cracks extending traverse the coating thickness under spherical indentation are investigated within the framework of linear fracture mechanics. The J-integral associated to such cracks was computed. The evolution of J-integral vs the crack length and the indentation depth was studied. The effects of the interlayer, the coating and the substrate on the J-integral evolution were discussed. The results show that a suitable metallic interlayer can improve the fracture resistance of the coating systems under the same indentation conditions through reducing the J-integral.  相似文献   
999.
The effect of a second non-singular term of mode I in the vicinity of the tip of a V-notched crack is discussed. The undetermined eigenvector coefficients of singular and non-singular terms of eigenfunction expansion were calculated by the numerical analysis method using the reciprocal work contour integral method (RWCIM) based on Betti's reciprocal work theorem and finite-element analysis. This study demonstrates that the second non-singular term of mode I can have a significant effect on the size and shape of plastic zones as an additional fracture mechanics parameter along with the conventional parameter K .  相似文献   
1000.
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