Impulsive Problems for Fractional Partial Neutral Functional Integro-Differential Inclusions with Infinite Delay and Analytic Resolvent Operators

In this paper, the existence of mild solutions for a class of impulsive fractional partial neutral functional integro-differential inclusions with infinite delay and analytic α-resolvent operators in Banach spaces is investigated. Sufficient conditions for the existence are derived with the help of the fixed-point theorem for discontinuous multi-valued operators due to Dhage and the fractional power of operators combined with approximation techniques. An example is provided to illustrate the theory.     

三种长链烷氧基苯甲酰基硫脲衍生物的合成及其凝胶行为

以没食子酸和溴代十四烷为原料，经过烷基化、醇化、酸化及卤代得到中间产物3,4,5-三（十四烷基）苯甲酰氯（1），化合物1通过一锅法首先与硫氰酸铵反应，然后分别与对硝基苯胺、对硝基苯肼和2,4-二硝基苯肼作用得到3种长链烷氧基苯甲酰基硫脲衍生物2、 3和4，其结构经¹H NMR， ¹³C NMR， IR和MS确证。并考察了3种化合物在20种常见溶剂中的凝胶行为。     

Traveling fronts in diffusive and cooperative Lotka–Volterra system with nonlocal delays

This paper is concerned with a diffusive and cooperative Lotka–Volterra model with distributed delays and nonlocal spatial effect. By using an iterative technique recently developed by Wang, Li and Ruan (Traveling wave fronts in reaction-diffusion systems with spatio-temporal delays, J. Differential Equations 222 (2006), 185–232), sufficient conditions are established for the existence of traveling wave front solutions connecting the zero and the positive equilibria by choosing different kernels. The result is an extension of an existing result for Fisher-KPP equation with nonlocal delay and is somewhat parallel to the existing result for diffusive and cooperative Lotka–Volterra system with discrete delays. Supported by the NNSF of China (10571078) and the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education of China.     

A novel traceless route to synthesize 3,5-disubstituted-1,2,4-triazoles on PEG6000

A novel traceless route to 3,5-disubstituted-1,2,4-triazoles has been described, which allows the incorporation of two elements of diversity. This method provided a library of 3,5-disubstituted-1,2,4-triazoles with high yields and purity.     

PEG-SO3H as an efficient and reusable catalyst for chemoselective synthesis of 1,1-diacetates

An efficient and convenient procedure of the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature,in the presence of PEG-SO₃H is reported.PEG-SO₃H acts as a catalyst and can be recovered and reused eight times without apparent loss of its catalytic activity.     

On the catalytic role of Re+ in the oxygen transport activation of N2O by CO

The mechanism of the cyclic reaction N₂O(¹∑) + CO(¹∑⁺) → N₂(¹∑ _g ⁺ ) + CO₂(¹∑ _g ⁺ ) catalyzed by Re⁺ has been investigated on quintet and septet potential energy surfaces (PES). The reactions were studied by the B3LYP density functional method and the CCSD(T) theory. The calculated results of different PES show that the reaction proceeds in a two-step manner and spin crossing between different PES occurs. The involving crossing points (CPs) between the quintet and septet PES have been discussed by means of the intrinsic reaction coordinate approach. And the O-atom affinities testified that Re⁺ can capture O from N₂O and transfer O atom to CO in the two spin state, which are thermodynamically allowed. Furthermore, the spin–orbit coupling (SOC) is calculated between electronic states of different multiplicities at the CPs. For CP1 and CP2, the computed SOC constants are 8.34 and 10.09 cm^?1, respectively, obtained by using one-electron spin–orbit Hamiltonian in GAMESS. Therefore, the intersystem crossing at CP1 and CP2 occurs with a little probability because of the small SOC involved.     

Theoretical studies of the reactions of M+ (M = Ta,W, Re) with CS2

Gas-phase CS₂ activation by M⁺ (M = Ta, W, Re) was studied by the B3LYP density functional method.The geometries for reactants, transition states, and products were completely optimized. CS₂ activation mediated by M⁺ (M = Ta, W, Re) were found to be a spin-forbidden process as a result of the crossing among the multistate energetic profiles. On the basis of the Hammond postulate, this was a typical two-state reactivity reaction. Among the different potential energy surfaces, the crossing points had been explored. The spin–orbit coupling (SOC) was also calculated between the electronic states of different multiplicities at the crossing point to estimate the intersystem crossing probability. For CP1, CP2, and CP4, the computed SOC constants were 80.28, 128.65, and 526.77 cm^?1, which obtained by using one-electron spin–orbit Hamiltonian in Gaussian 09.     

Monotone travelling fronts of a food-limited population model with nonlocal delay

This paper deals with the existence of monotone travelling fronts of a diffusive food-limited population model with nonlocal delay. By choosing different kernel functions, we establish some existence criteria of monotone travelling fronts connecting two uniform steady states of the model, which include, improve and/or complement a number of existing results.     

PANI/AMTES-TiO2纳米复合材料的制备及其光催化性能

首先用偶联剂苯胺基甲基三乙氧基硅烷(AMTES)对纳米TiO2进行表面修饰(AMTES-TiO2), 然后通过苯胺单体在AMTES-TiO2表面的原位化学氧化接枝聚合, 制备了基于共价键结合的聚苯胺(PANI)/AMTES-TiO2纳米复合光催化材料. 用红外光谱(FTIR), X射线衍射(XRD), 热重分析(TGA), 紫外-可见漫反射光谱(UV-Vis-DRS)和荧光发射光谱(PL)等技术对复合材料进行了表征. 以亚甲基蓝(MB)为目标降解物, 研究了PANI/AMTES-TiO2复合材料在太阳光和紫外光下的光催化性能. 结果表明:聚苯胺敏化拓宽了TiO2的光谱响应范围, 复合材料在紫外和可见光区都有较强的吸收, 提高了光能的利用率和光生载流子的分离效率, 使复合材料表现出较高的光催化活性; 苯胺与AMTES-TiO2的质量比(w)对复合材料的光催化活性有较大影响, 当w为0.025时, 复合材料在两种光源下的催化性能均优于TiO2和AMTES-TiO2.     

Study and optimal simulation of 4H-SiC floating junction Schottky barrier diodes’ structures and electric properties

This paper stuides the structures of 4H-SiC floating junction Schottky barrier diodes. Some structure parameters of devices are optimized with commercial simulator based on forward and reverse electrical characteristics. Compared with conventional power Schottky barrier diodes, the devices are featured by highly doped drift region and embedded floating junction layers, which can ensure high breakdown voltage while keeping lower specific on-state resistance, and solve the contradiction between forward voltage drop and breakdown voltage. The simulation results show that with optimized structure parameter, the breakdown voltage can reach 4.36 kV and the specific on-resistance is 5.8 mΩ·cm2 when the Baliga figure of merit value of 13.1 GW/cm2 is achieved.