A Novel Interface-Gate Structure for SOI Power MOSFET to Reduce Specific On-Resistance

A novel silicon-on-insulator （SOI） power metM-oxide-semiconductor field effect transistor with an interface-gate （IG SOI） structure is proposed, in which the trench polysificon gate extends into the buried oxide layer （BOX） at the source side and an IG is formed. Firstly, the IG offers an extra accumulation channel for the carriers. Secondly, the subsidiary depletion effect of the IG results in a higher impurity doping for the drift region. A low specific on-resistance is therefore obtained under the condition of a slightly enhanced breakdown voltage for the IG SOI. The influences of structure parameters on the device performances are investigated. Compared with the conventional trench gate SOI and lateral planar gate SOI, the specific on-resistances of the IG SOI are reduced by 36.66% and 25.32% with the breakdown voltages enhanced by 2.28% and 10.83% at the same SOI layer of 3 μm, BOX of 1 μm, and half-cell pitch of 5.5 μm, respectively.

An efficient technique for recovering responses of parameterized structural dynamic problems

In this article,an effective technique is developed to efficiently obtain the output responses of parameterized structural dynamic problems.This technique is based on the conception of reduced basis method and the usage of linear interpolation principle.The original problem is projected onto the reduced basis space by linear interpolation projection,and subsequently an associated interpolation matrix is generated.To ensure the largest nonsingularity,the interpolation matrix needs to go through a timenode choosing process,which is developed by applying the angle of vector spaces.As a part of this technique,error estimation is recommended for achieving the computational error bound.To ensure the successful performance of this technique,the offline-online computational procedures are conducted in practical engineering.Two numerical examples demonstrate the accuracy and efficiency of the presented method.

Pd catalysts supported on rGO-TiO_2 composites for direct synthesis of H_2O_2: Modification of Pd^(2+)/Pd^0 ratio and hydrophilic property

The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO_2(rGP-x) composites with a variation of reduced graphene oxide(rGO) content were synthesized by hydrothermal method. Pd/rGP-x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H_2O_2 from H2 and O_2. The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman spectroscopy.The ratio of Pd^(2+)/Pd^0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H_2O_2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H_2O_2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H_2O_2 selectivity and productivity of Pd/r GP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd^(2+)/Pd^0 and hydrophobicity of the catalyst.

Grouping of amino acids and recognition of protein structurally conserved regions by reduced alphabets of amino acids

Sequence alignment is a common method for finding protein structurally conserved/similar regions. However, sequence alignment is often not accurate if sequence identities between to-be-aligned se- quences are less than 30%. This is because that for these sequences, different residues may play similar structural roles and they are incorrectly aligned during the sequence alignment using substitu- tion matrix consisting of 20 types of residues. Based on the similarity of physicochemical features, residues can be clustered into a few groups. Using such simplified alphabets, the complexity of protein sequences is reduced and at the same time the key information encoded in the sequences remains. As a result, the accuracy of sequence alignment might be improved if the residues are properly clustered. Here, by using a database of aligned protein structures (DAPS), a new clustering method based on the substitution scores is proposed for the grouping of residues, and substitution matrices of residues at different levels of simplification are constructed. The validity of the reduced alphabets is confirmed by relative entropy analysis. The reduced alphabets are applied to recognition of protein structurally conserved/similar regions by sequence alignment. The results indicate that the accuracy or efficiency of sequence alignment can be improved with the optimal reduced alphabet with N around 9.

Derivation and analysis on the analytical structure of interval type-2 fuzzy controller with two nonlinear fuzzy sets for each input variable

Type-2 fuzzy controllers have been mostly viewed as black-box function generators. Revealing the analytical structure of any type-2 fuzzy controller is important as it will deepen our understanding of how and why a type-2 fuzzy controller functions and lay a foundation for more rigorous system analysis and design. In this study, we derive and analyze the analytical structure of an interval type-2 fuzzy controller that uses the following identical elements: two nonlinear interval type-2 input fuzzy sets for each variable, four interval type-2 singleton output fuzzy sets, a Zadeh AND operator, and the Karnik-Mendel type reducer. Through dividing the input space of the interval type-2 fuzzy controller into 15 partitions, the input-output relationship for each local region is derived. Our derivation shows explicitly that the controller is approximately equivalent to a nonlinear proportional integral or proportional differential controller with variable gains. Furthermore, by comparing with the analytical structure of its type-1 counterpart, potential advantages of the interval type-2 fuzzy controller are analyzed. Finally, the reliability of the analysis results and the effectiveness of the interval type-2 fuzzy controller are verified by a simulation and an experiment.

Correlation of cooperatively localized rearrangement on the "fluidized domain" in glass substances (or polymers) to their fragility Ⅲ:Theory of dynamic fragility at isochoric state

A set of universal equations on the reduced stress relaxation modulus with K-W-W stretched exponential function has been derived from the dynamics of α and β structural relaxation processes. In the present work, the K-W-W decay function is used to define the three types of relaxations (single α, single β relaxation and α-β co-relaxation), then their average times of relaxation are theoretically calculated from the reduced shear stress relaxation modulus and the relaxation time spectrum function H(τ). When the average time of co-relaxation, the reference temperatures (ficitive Tf and glass transition Tg) and the isostructural parameter achieved from the conditions of isostructural glass state are introduced into the reduced shear stress relaxation modulus (GT) under the equilibrium state, a set of correlations between isochoric fragility index (mvα, mvβ and mvαβ) and the coupling strength (α and β) under the reference temperatures are derived from the exact definition of isochoric fragility. So the theory of dynamic fragility for glass substances at isochoric state is developed. The theory can predict the following main features of structural relaxations and behavior of isochoric fragility: the temperature dependence of peak relaxation frequency exhibits a bifurcation with a pair of single α and single β relaxations; the temperature dependence of Stickel equation on 1/T exhibits two crossovers with VFTH(1) and VFTH(2) at the temperatures of Tf and Tg regime; there are two linear correlations between isochoric fragility index (mvα and mvβ) and the coupling strength. Fine agreements between the theoretical calculation and experimental results are obtained.