A Generic and Effective Strategy for Highly Effective “Intrinsic”Molecular Luminescence in Condensed State

正Organic light-emitting(OLE)materialshave been extensively studied due to their easy mod-ification,However,the easy crystallization to re-sult in instable spectral performance and quenchingeffect of luminescence,poor processability and lowthermal stability have limited their applications.Polyhedral oligomeric silsesquoixanes(POSS)are a class of inorganic compounds with nanoscale     

Effective Particle–Particle Interaction in Incommensurable CDW Systems

We study the pairing potential induced by fluctuations around a static charge-density wave (CDW) with scattering vector Q by means of the Fröhlich transformation. For general commensurability M, defined as |k + M Q = |k, we find that the intraband pair scattering within the M subbands scales with M, whereas the interband pair scattering becomes suppressed with increasing CDW order parameter. As a consequence, superconductivity is suppressed when the Fermi energy is located between the subbands, as it is usually the case for nesting induced CDWs, but due to the vertex renormalization it can be substantially enhanced when the chemical potential is shifted sufficiently inside one of the subbands. Additional magnetic stripe order restricts this enhancement to the case in which the stripes are half-filled.     

Radiative heat transfer of ultra‐fine powder insulation in nonplanar geometry

Abstract

The purpose of this work is to study the radiation heat transfer through some typical ultra‐fine powder insulations. The spectral extinction coefficients for these powders have been measured via infrared transmission measurements. The experimental results are compared with both the dependent and independent scattering and absorption theoretical calculations. The radiative transport process is modeled by the diffusion approximation method. Based on the experimental data, the radiant thermal conductivity between two concentric cylinders and spheres was calculated. The results show that the radiant thermal conductivity between two concentric spheres is about 50 percent higher than that between two cylinders.     

Studies of the changes in the geometry of grain boundaries and grains during recovery/continuous recrystallization in α-Fe

Samples of -Fe (Armco) have been deformed by 50% in compression. These have then been annealed at 400 °C, considerably below the conventional recrystallization temperature, and the evolution of grain size and shape quantified. Initially the grain size is found to decrease whilst, at the same time, the grain-shape anisotropy also decreases. It is suggested that a continuous recrystallization process which favours the generation of higher angle grain boundaries is the underlying mechanism. Annealing for longer times gives rise to an increase in grain size with the development of undulations on the grain surfaces. The mechanism suggested for this behaviour involves the annihilation of segments of sub-boundaries on to a pre-existing boundary from either side of the boundary.     

《Effective C#》翻译札记

最近在翻译Bill Wagner先生的《Effective C#》一书，由于自己早先也有写作Effective.NET的打算，所以对书中很多条款，也有很多自己的思考。如果作为译注来添加，担心把最后的译本添得四不像，不添又甚感遗憾。遂考虑把翻译过程中自己的所思所想直接记录下来，并在自己的blog(http：//blog．dreambrook．com／jzli／)上开辟专门的Effective C#区，供大家讨论打磨，弥补作／译者认识不足的地方，相信也许可以收到正常出版渠道不能取得之效果。     

Effective Masses and Characteristic Velocities of Charge Carriers in Low-Dimensional ANB8 –N Structures

Technical Physics Letters - Simple structural models and a previously proposed theory have been used for estimating bandgap widths, effective masses, and effective velocities of charge carriers in...     

The Effective Mass of Impurity–bound Polaron in a Two- and Three-Dimensional Quantum Dot

Within the framework of the Landau–Pekar variational method we have derived an analytical expression for the ground-state binding energies and the effective mass of an electron bound to a Coulomb impurity in a polar semiconductor quantum dot (QD) with parabolic confinement in both two and three dimensions. We have also calculated the number of phonons in the cloud of this bound polaron. It is found that the effective mass increase with increasing the Coulomb binding parameter and increase with the decrease in size of the QD. The results also indicate that this effect becomes much more pronounced with decreasing dimensionality.     

Theoretical analysis of influence of crack dimensions and geometry on mass transport in corrosion–fatigue cracks

Abstract

Theoretical models are developed to describe the concentration of dissolved species in a corrosion–fatigue crack. The models are based on two separate reaction processes: the cathodic reduction of oxygen on the crack walls, and the anodic dissolution of metal at the crack tip. The concentrations of species in a trapezoidal crack are calculated for a range of crack depths from 0·25 to 20 mm, and for different minimum/maximum load ratios, stress–intensity factors, and frequencies, assuming single–edge–notch geometry. The relative importance of diffusion and fluid flow as functions of these parameters is analysed. The influence the geometry of the specimen has on the composition of the solution is determined, and the use of parallel–sided cracks is discussed. The implications of the conclusions for corrosion–fatigue crack growth are assessed.

MST/73     

Effective Medium Approximation for Nonlinear Composite Media

We build the perturbation expansion method for nonlinear composite media and extend the EMA fornonlinear effective conductivity. Using the solutions of boundary-value problems of a cylindrical in-clusion, we derive formulae for nonlinear effective conductivity.     

Numerical study on influence of exit geometry in gas–solid flow hydrodynamics of HDCFB riser by CPFD

The understanding of gas–solid flow is of great importance for various high-density circulating fluidized bed (HDCFB) practices. In this work, the effects of exit geometry on the gas–solid flow behavior in an HDCFB riser were numerically studied by using the computational particle fluid dynamics (CPFD) method. The simulated results were compared against experimental data on bed pressure and solid volume fraction distributions along the riser and a satisfactory agreement was found between them, which indicated the capability of the CPFD for the HDCFB riser simulation. Thereafter, simulations were conducted for the HDCFB risers with six different exit geometries and comparisons of hydrodynamics characteristics between each other were made. It was found that exit geometry significantly affected the axial solid volume fraction distribution through the whole riser. The abrupt exits gave rise to higher SRT than the smooth ones due to the solids back-mixing and packing effects. The angle between the exit duct and the horizontal plane also has a great influence on the gas–solid hydrodynamics and the abrupt exit with 15° was found to be appropriate for HDCFB riser due to its promotion on solid dispersion and reduction in solids back-mixing and packing.     

Effective Elastic Moduli of Ceramics with Pores

A contribution is given to the theoretical research on the stiffness of ceramic materials, under the approximation of the average stress field, the relation E = E0(1 -p)/(1+ 2.5p) is derived to describe the dependence of the modulus of etasticity on porosity. The prediction of this model is consistent with the experimental data from several ceramics such as reacting sintered Si3N4,MgO and MgAl2O3.     

Effective wavelength calibration for moiré fringe projection

The fringe patterns seen when using moiré instruments are similar to the patterns seen in traditional interferometry but differ in the spacing between consecutive fringes. In traditional interferometry, the spacing is constant and related to the wavelength of the source. In moiré fringe projection, the spacing (the effective wavelength) may not be constant over the field of view and the spacing depends on the system geometry. In these cases, using a constant effective wavelength over the field of view causes inaccurate surface height measurements. We examine the calibration process of the moiré fringe projection measurement, which takes this varying wavelength into account to produce a pixel-by-pixel wavelength map. The wavelength calibration procedure is to move the object in the out-of-plane direction a known distance until every pixel intensity value goes through at least one cycle. A sinusoidal function is then fit to the data to extract the effective wavelength pixel by pixel, yielding an effective wavelength map. A calibrated step height was used to validate the effective wavelength map with results within 1% of the nominal value of the step height. The error sources that contributed to the uncertainty in determining the height of the artifact are also investigated.     

Effective scheme for preparation of multi-atom Greenberger–Horne–Zeilinger states in coupled cavities via adiabatic passage

Abstract

A scheme is proposed to deterministically generate multi-atom Greenberger–Horne–Zeilinger (GHZ) states trapped in coupled cavities, which is based on the adiabatic passage of the dark state. The scheme does not need to adjust the interaction time accurately and is insensitive to the fluctuations of some experimental parameters. However, we should choose the appropriate Rabi frequencies of the classical fields to achieve the optimal characteristic of the system. In addition, we also demonstrate numerically that it is robust against decoherence caused by the cavity decay and atomic spontaneous emission.     

Effective preparation of the N-dimension spin Greenberger–Horne–Zeilinger state with quantum dots embedded in microcavities

We propose a scheme for preparation of the N-dimension spin Greenberger–Horne–Zeilinger state by exploiting quantum dots (QDs) embedded in microcavities. Numerically analysed results show that with the spin-selective photon reflection from the cavity, we can complete the scheme assisted by one polarized photon with high fidelity and 100% successful probability in principle. Furthermore, the set-up is just composed of simple linear optical elements, delay lines and conventional photon detectors, which are feasible with existing experimental technology. Moreover, QDs have numerous admirable features in weak-coupling regime, which are practicable in realistic cavity quantum electrodynamics system shown by previous numerical simulations and experiments. Therefore, our scheme might be realized in near future.     

Evaluation of in vitro degradation of PCL scaffolds fabricated via BioExtrusion – Part 2: Influence of pore size and geometry

The in vivo degradation processes by which scaffolds degrade and are replaced by neo-tissue are complex and may be influenced by many factors, including environmental conditions, material properties, porosity and 3D architecture. The present study is focused on the influence of design parameters, filament distance (FD) and lay-down pattern, on the degradation kinetics of Polycaprolactone (PCL) scaffolds obtained via BioExtrusion. Through the variation of design parameters it was possible to obtain two groups of scaffolds with distinct pore geometry and size. The in vitro degradation was performed in simulated body fluid (SBF) and in phosphate buffer solution (PBS) for six months. Our results highlight a more complex degradation pattern of the scaffolds in SBF than in PBS, probably related to a mineral deposition. Significant statistical differences in weight loss values at month 6, allowed us to conclude that degradation kinetics of PCL scaffolds is strongly influenced by the pore size.     

《Effective C#》翻译札记（二）

最小化内存垃圾Item 16：Minimize Garbage     

Effective Excitation of Magnetoelectric Voltage Harmonics in a Ferromagnet–Piezoelectric Structure by Current Passing through the Magnetic Layer

Technical Physics Letters - The magnetoelectric (ME) effect in a planar amorphous ferromagnet–piezoelectric lead zirconate titanate (PZT) composite structure can be effectively excited by...