Correlation decay for an intermittent area-preserving map

We consider an area-preserving map which is almost everywhere hyperbolic, with a single marginal fixed point. Correlation decay is studied both by direct simulation of autocorrelations of smooth observables and by recurrence statistics on longer time scales. While on the time scale on which correlations are observed directly results are consistent with exponential relaxation, a transition to power-law is observed in the “sticking” times statistics.     

复合三子镜稀疏孔径光瞳结构的研究

由于在截止频率区域内稀疏孔径系统的调制传递函数(MTF)比全孔径系统的调制传递函数下降,甚至调制传递函数可能出现零点而影响成像质量,通过稀疏孔径系统的结构优化可以获得调制传递函数分布比较理想的孔径结构。给出了基于实际空间截止频率ρR和子孔径直径的稀疏孔径结构优化准则,对复合三子镜稀疏孔径结构进行优化,分析了优化前后的调制传递函数变化,并对优化结构的复合三子镜稀疏孔径系统模拟成像和维纳滤波,比较优化前和优化后稀疏孔径结构的成像情况。结果表明结构优化是稀疏孔径光学系统设计的一个关键部分,应用的优化准则对稀疏孔径结构优化是合理的,通过结构优化可以使复合三子镜稀疏孔径系统的成像质量得到改善。     

Ferromagnetic Properties of Bond-Dilution and Random Positive or Negative Uniaxial Anisotropy Blume-Capel Model

We study the ferromagnetic properties of spin-1 system, which is considered in the frame of the bonddilution and random positive or negative anisotropy Blume-Capel model in the effective field theory and a cutting approximation. The investigation of phase diagrams displays some rich properties of the trajectory of tricritical point,reentrant phenomena at low temperatures. Under certain both bond concentrations and random negative anisotropy,there are new transition lines of double tricritical points. So special emphasis is placed on the influence of the bond dilution and random anisotropy on phase diagrams. The magnetizations of the system are also discussed. Some results have not been revealed in previous reports.     

Study on'the α-Thiocarbonylthioformamide Ⅱ——Dehydrogenation of tetrahydronaphthalene

α-Thiocarbonylthioformamides were synthesized in 1980^[1-3]. Authors first explored their dehydrogenation reaction at high temperature. In our initial experiment, α-Thiobenzoylthioformmorpholine(l) was heated with diethyl acetylene dicarboxylate in tetrahydronaphthalene(2). The reaction is shown as following.     

Study on the Reaction of α-Ketohemithioacetal

Aromatic α-sulfinyl carboxylic acids can be rearranged to hemithioacetals or other derivatives of glyoxylic acid under the action of acid reagents was first reported by Pummerer¹. Later, Russell and coworkers applied this rearrangement to β-ketosulfoxides, synthesized α-ketohemithioacetal², which can be transformed to α-keto alcohol, α-keto aldehyde and α-hydroxy alcohol, α-hydroxy acid³. Furthermore, Hall and Poet reported that α-ketohemithio-acetal can be rearranged to the corresponding α-hydroxythioester in the presence of magnesium nitrate and sodium acetate or tertiary amine⁴. However, few reports of reaction of α-ketohemithioacetal can be seen in literature.     

Direct electrochemistry of membrane-entrapped horseradish peroxidase.: Part I. A voltammetric and spectroscopic study

This paper reports the electrochemical behaviour, relative to the Fe(III)–Fe(II) conversion, of horseradish peroxidase (HRP) entrapped within a solid matrix, at a pyrolytic graphite electrode. The results indicate that (i) immobilization enhances the electron exchange between the protein and the electrode surface; (ii) reversible electron transfer (eT) is achieved within a wide pH range (pH 3.0–12.0) even in the absence of mediators, (ii) the embedded protein shows native-like structural properties and increased stability. The results obtained may be of potential value, since they represent a first step for engineering a novel `solid-state' electrode system, of importance for basic and applied biochemistry.     

Exotic (E6) particles in e+e− annihilation

Fermion mixing is analyzed in (E₆) extensions of the standard model. Cross sections and signatures for the production in present and future e⁺e⁻ colliders are discussed in detail.     

New electrochemically synthesized copolymers: poly(difluorenyl-ethylenes)

Synthesis and cyclic voltammetry data of novel copolymers containing difluorenyl-ethylene units in the conjugated backbone are reported.     

窄域上2D弱阻尼KdV方程的局部吸引子

得到了窄域上2D的非自共轭且非扇形的弱阻尼KdV方程的局部吸引子的存在性.