基于腔辅助相互作用的远距离信息传递

提出了一种基于腔辅助相互作用的远距离信息传递的方案.在该方案中,通过让一束相干光和一个囚禁在腔里面的原子进行相互作用,可以使相干光产生一个可控的相位偏移.用这种腔辅助相互作用完成了原子态和光场态之间信息的相互转移.最后我们演示了远距离信息传递方案,该方案在当前实验条件下是可行的,并且在理想条件下,成功的概率几乎为1.     

Effect of multiple H‐bonding on the properties of polyimides containing the rigid rod groups

To investigate the influence of hydrogen bonding on the properties of polyimides (PIs) containing rigid rod‐like groups, five symmetrical diamines containing benzimidazole, benzoxazole, and hydroxy group were synthesized, and then a series of PIs were prepared. Results showed that hydroxyl‐containing poly(benzoxazole imide)s possess higher glass transition temperature (T_g) and dimensional stabilities than their corresponding poly(benzoxazole imide)s. Moreover, the corresponding poly(benzimidazole imide)s presented the best performances, such as the highest T_g, the highest char yield and the highest dimensional stabilities. The influence of hydrogen bonding of benzimidazole on the properties of PIs was stronger than that of hydroxyl groups. Hydroxyl‐containing poly(benzoxazole imide)s were formed in crosslinking structures after heat treatment at 400 °C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 570–581     

Prediction of binary interaction coefficients in grain boundary segregation

A simple semiempirical method is proposed for prediction of the values of the binary interaction coefficients in grain boundary segregation (Fowler interaction). The method is based on the volume solid solubility, the maximum possible concentration of the solute at the grain boundary, and an additional parameter that represents an activity exponent of both the solute and the host metal. Values of the interaction coefficients for numerous solutes in α‐iron are predicted. The comparison with available literature data shows reasonable agreement.     

The computational fluid dynamics modelling of the autorotation of square,flat plates

This paper examines the use of a coupled Computational Fluid Dynamics (CFD) – Rigid Body Dynamics (RBD) model to study the fixed-axis autorotation of a square flat plate. The calibration of the model against existing wind tunnel data is described. During the calibration, the CFD models were able to identify complex period autoration rates, which were attributable to a mass eccentricity in the experimental plate. The predicted flow fields around the autorotating plates are found to be consistent with existing observations. In addition, the pressure coefficients from the wind tunnel and computational work were found to be in good agreement. By comparing these pressure distributions and the vortex shedding patterns at various stages through an autorotation cycle, it was possible to gain important insights into the flow structures that evolve around the plate. The CFD model is also compared against existing correlation functions that relate the mean tip speed ratio of the plate to the aspect ratio, thickness ratio and mass moment of inertia of the plate. Agreement is found to be good for aspect ratios of 1, but poor away from this value. However, other aspects of the numerical modelling are consistent with the correlations.     

Study of size dependent features of swift heavy ion irradiation in nanosized zinc ferrite

In the present work zinc ferrite nanoparticles of different crystallite size were irradiated with 200 MeV Ag¹⁵⁺ ion beam. The structural and magnetic characterization performed for these samples indicate the presence of size dependent irradiation induced changes in the nanoparticles. The superparamgnetic nanoparticles do not alter their behavior after irradiation; however paramagnetic samples exhibit weak ferrimagnetism in the irradiated specimen. Results obtained from these measurements are in agreement with results obtained from the electron paramagnetic resonance spectroscopy.     

A simple line shape technique for electron number density diagnostics of helium and helium-seeded plasmas

The results of an experimental study of the He I 447.1 nm line and its forbidden component at high electron number density are presented and compared with profiles calculated using computer simulation method. Michelson interferometer at 632.8 nm was used to measure plasma electron number density in the range (1–7) × 10²³ m^− 3 while electron temperatures for the same experimental conditions in the range of 25 000 K to 35 000 K were determined using several spectroscopic techniques. The agreement of experimental overall line shape with computer simulation results is within 10% of what is well within theoretical and experimental uncertainty. This favorable comparison enabled the development of a simple approximate formula for the evaluation of electron number density from the measurement of wavelength separation between peaks of allowed and forbidden lines. This technique of plasma diagnostics is not sensitive to the presence of self-absorption of strong He I allowed line. The derivation of approximate formula with estimated accuracy of 15% was followed by detailed comparison with other experimental and theoretical data.     

Thermal Entanglement of an XY Two-Qutrit Spin Chain with Dzialoshinski-Moriya Interaction

The effect of Dzialoshinski-Moriya （DM） interaction on thermal entanglement of an XY two-qutrit spin chain is investigated. We find that DM interaction and the anisotropy parameter can enhance quantum thermal entanglement to a maximal value individually. However, when both of them take large values, the entanglement is not enhanced, but is destroyed. Our analysis will shed some light on the understanding of the effect of the DM interaction on thermal entanglement of an XY two-qutrit spin chain.     

Fabrication and transformation of dense SnO2 via laser ablation condensation

Dense SnO₂ nanocondensates with fluorite-type-related structures have been synthesized via severe heating-cooling under energetic Nd-YAG laser pulse irradiation of the Sn target in oxygen ambient. Transmission electron microscopic observations indicated that the fluorite type transformed in a martensitic manner into a baddeleyite-type structure with accompanied dislocations, twinning, commensurate shearing and shape change. The Pa3¯-modified fluorite-type structure was hardly observed possibly due to its transformation into α-PbO₂ type and then rutile-type structures in the dynamic process.     

A multi-beam ion/electron spectra-microscope design

This paper presents the design of a multi-beam charged particle instrument that simultaneously focuses electrons, gallium, oxygen and cesium ions onto the same sample. In addition, the instrument has provision to capture the spectra of both secondary electrons and ions in parallel. The mass spectrometer part of the instrument is expected to detect and identify secondary ion species across the entire range of the periodic table, and also record a portion of their emitted energy spectrum. The electron energy spectrometer part of the instrument is designed to acquire the entire range of scattered electrons, from the low-energy secondary electrons through to the elastic backscattered electrons.     

Loschmidt echo of a central spin coupled to an XY spin chain: Role of three-site interaction

Effects of two types of three-site interaction, i.e., XZX+YZY and XZY−YZX, on Loschmidt Echo (LE) of a central spin coupled to an XY spin chain are studied. The dynamical evolution behaviors of the LE are investigated analytically and numerically. The XZX+YZY type of three-site interaction (α₁) can shift the critical points of the magnetic field λ. At the critical points |λ−α₁|=1, the decay of the LE is enhanced. The role of the XZY−YZX type of three-site interaction (α₂) depends on its strength. In some specific intervals, α₂ can remarkably delay the decay of the LE.