Kondo-Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Using an equation-of-motion technique,we theoretically study the Kondo-Fano effect in the T-shaped double quantum dots coupled to two ferromagnetic leads by the Anderson Hamiltonian.We calculate the density of states in this system by solving Green function.Our results reveal that the density of states show some noticeable characteristics not only depending upon the interdot coupling t ab,the energy level ε d1 of the side coupled quantum dot QD b,and the relative angle θ of magnetic moment M,but also the asymmetry parameter α in ferromagnetic leads and so on.All these parameters greatly influence the density of states of the central quantum dot QD a.This system is a possible candidate for spin valve transistors and may have potential applications in the spintronics.     

Analysis of the modulation mechanisms of the electric field and breakdown performance in AlGaN/GaN HEMT with a T-shaped field-plate

A novel Al Ga N/Ga N high electron mobility transistor(HEMT) with a source-connected T-shaped field-plate(ST-FP HEMT) is proposed for the first time in this paper. The source-connected T-shaped field-plate(ST-FP) is composed of a source-connected field-plate(S-FP) and a trench metal. The physical intrinsic mechanisms of the ST-FP to improve the breakdown voltage and the FP efficiency and to modulate the distributions of channel electric field and potential are studied in detail by means of two-dimensional numerical simulations with Silvaco-ATLAS. A comparison to the HEMT and the HEMT with an S-FP(S-FP HEMT) shows that the ST-FP HEMT could achieve a broader and more uniform channel electric field distribution with the help of a trench metal, which could increase the breakdown voltage and the FP efficiency remarkably. In addition, the relationship between the structure of the ST-FP, the channel electric field, the breakdown voltage as well as the FP efficiency in ST-FP HEMT is analyzed. These results could open up a new effective method to fabricate high voltage power devices for the power electronic applications.     

Static and dynamic responses of a microcantilever with a T-shaped tip mass to an electrostatic actuation

In this study, nonlinear static and dynamic responses of a microcantilever with a T-shaped tip mass excited by electrostatic actuations are investigated. The electrostatic force is generated by applying an electric voltage between the horizontal part of T-shaped tip mass and an opposite electrode plate. The cantilever microbeam is modeled as an Euler–Bernoulli beam. The T-shaped tip mass is assumed to be a rigid body and the nonlinear effect of electrostatic force is considered. An equation of motion and its associated boundary conditions are derived by the aid of combining the Hamilton principle and Newton's method.An exact solution is obtained for static deflection and mode shape of vibration around the static position. The differential equation of nonlinear vibration around the static position is discretized using the Galerkin method. The system mode shapes are used as its related comparison functions. The discretized equations are solved by the perturbation theory in the neighborhood of primary and subharmonic resonances.In addition, effects of mass inertia, mass moment of inertia as well as rotation of the T-shaped mass, which were ignored in previous works, are considered in the analysis. It is shown that by increasing the length of the horizontal part of the T-shaped mass, the amount of static deflection increases,natural frequency decreases and nonlinear shift of the resonance frequency increases. It is concluded that attaching an electrode plate with a T-shaped configuration to the end of the cantilever microbeam results in a configuration with larger pull-in voltage and smaller nonlinear shift of the reso-nance frequency compared to the configuration in which the electrode plate is directly attached to it.     

T型分支管道对油气爆炸强度的影响

为了研究T型分支结构对管道内油气混合物爆炸强度的影响规律,测试了不同初始体积分数条件下直管和具有T型分支管中爆炸波超压值,并利用有机玻璃透明管道对火焰传播规律进行了可视化研究。得到以下结论:(1)T型分支管道对油气爆炸有强化作用,在油气体积分数为1.2%至1.6%范围内表现最明显; (2)T型分支管道对油气爆炸的强化作用受管道横截面突扩和障碍物扰动以及波的反射、绕射三方面的影响; (3)火焰经过分支管道时,火焰阵面发生极大的扭曲,火焰表面积显著增大,燃烧速率增大,增强了热量和活性物质的输运速率,提高了爆炸波的强度; (4)在T型分支管道附近, 油气爆炸的压力突变增强, 是由压力波反射、绕射引起的温升效应和压力波引起湍流强度增强共同导致。     

SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTAL POLYMERS WITH T-SHAPED TWO-DIMENSIONAL MESOGENIC UNITS (Ⅱ)*

A series of liquid crystalline polymers with T-shaped two-dimensional mesogenic unitswere synthesized via low temperature solution polycondensation of 2-(4'-alkoxy-phenyl)hydroquinone with various diacyl dichlorides. The polymers were found to be nematic andshown thermotropic liquid crystalline behaviors through observations using DSC, polarizedmicroscopy and X-ray diffraction. The melting temperature T_m and the isotropizationtemperature T_i of the polymers change regularly with varying of the monomer structures.     

Laser direct patterning of the T-shaped ITO electrode for high-efficiency alternative current plasma display panels

The laser direct patterning technique is one of the new methods of direct etching process to replace the conventional photolithography. In this experiment, a Q-switched diode-pumped Nd:YVO₄ (λ = 1064 nm) laser was used to produce the indium-tin oxide (ITO) patterns with a complex T-shaped structure on glass substrate. The results showed that the overlapping rate of laser beam had a major effect on the quality of the edge of the ITO electrode. When the overlapping rate was about 75%, it was possible to obtain optimum linearity in the edge of patterned ITO electrode. By using the optimum conditions of 75% overlapping rate, 500 mm/s scanning speed, and 40 kHz repetition rate, an alternative current plasma display panels (AC PDPs) with T-shaped ITO electrode was fabricated and characterized. The discharging results showed that the AC PDPs with the laser ablated T-shaped ITO electrode had a better discharging characteristics compared to the conventional sample with wet-etched stripe-type ITO electrode.     

Stresses due to an adhesion crack in T-shaped junction of two orthotropic plates

The general solution of stresses is derived for a T-shaped junction of two thin plates with an adhesion crack.The plates are orthotropic.A shear force is applied on the crack surface.The analysis is based on the supposition that the stresses in each plate can be approximated by a plane stress condition.The results obtained are verified by numerical calculation of FEM.     

Reaction Pathways and Redox States in α-Selective Cobalt-Catalyzed Hydroborations of Alkynes

Cobalt(II) alkyl complexes supported by a monoanionic NNN pincer ligand are pre-catalysts for the regioselective hydroboration of terminal alkynes, yielding the Markovnikov products with α:β-(E) ratios of up to 97:3. A cobalt(II) hydride and a cobalt(II) vinyl complex appear to determine the main reaction pathway. In a background reaction the highly reactive hydrido species specifically converts to a coordinatively unsaturated cobalt(I) complex which was found to re-enter the main catalytic cycle.     

带内螺旋翅片的T形翅片管传热特性研究

以钢质光滑管、T形翅片管及带内螺旋翅片的T形翅片管为元件，以氟利昂113—水为介质的单管池沸腾传热试验的结果表明，在试验范围内，带内螺旋翅片的T形翅片管的总传热系数是光滑管的1．9～2．6倍，是T形翅片管的1．21～1.29倍。用Wilson图解分析法得到的这种新管型的管内单相流体给热系数的方程为：hi＝0．0244λ／DiRe(0.8)Pr(0.3)，管外沸腾给热系数的方程为：h0＝5104．3q(0．04)。对试验结果和这种新管型的传热强化机理进行了讨论。     

Synthesis and Photophysical Properties of T-Shaped Coinage-Metal Complexes

The photophysical properties of a series of T-shaped coinage d¹⁰ metal complexes, supported by a bis(mesoionic carbene)carbazolide (CNC) pincer ligand, are explored. The series includes a rare new example of a tridentate T-shaped Ag^I complex. Post-complexation modification of the Au^I complex provides access to a linear cationic Au^I complex following ligand alkylation, or the first example of a cationic square planar Au^III−F complex from electrophilic attack on the metal centre. Emissions ranging from blue (Cu^I) to orange (Ag^I) are obtained, with variable contributions of thermally-dependent fluorescence and phosphorescence to the observed photoluminescence. Green emissions are observed for all three gold complexes (neutral T-shaped Au^I, cationic linear Au^I and square planar cationic Au^III). The higher quantum yield and longer decay lifetime of the linear gold(I) complex are indicative of increased phosphorescence contribution.