对物体沿散斑片纵向移动二次曝光全息干涉条纹的诠释

从光学几何关系出发,推导了在平行光照明、物体沿散斑片纵向方向微小移动情况下的一种全息干涉条纹的解释方法.该方法可以根据任一瞬间的条纹间距测量物体的位移,并适用于实时全息监测的定量分析,对全息干涉计量术提供有效的条纹解释方法和物体位移的计算方法.     

Hydrocarbon film growth by energetic CH3 molecule impact on SiC (0 0 1) surface

Classic molecular dynamics (MD) calculations were performed to investigate the deposition of thin hydrocarbon film. SiC (1 0 0) surfaces were bombarded with energetic CH₃ molecules at impact energies ranging from 50 to 150 eV. The simulated results show that the deposition yield of H atoms decreases with increasing incident energy, which is in good agreement with experiments. During the initial stages, with breaking Si-C bonds in SiC by CH₃ impacting, H atoms preferentially reacts with resulting Si to form Si-H bond. The C/H ratio in the grown films increases with increasing incident energy. In the grown films, CH species are dominant. For 50 eV, H-Csp3 bond is dominant. With increasing energy to 200 eV, the atomic density of H-Csp2 bond increases.     

Hartmann势加新环型势的相对论束缚态解(英文)

在矢势与标势相等的情况下,对Hartmann势加新环型势的Klein-Gordon方程精确求解.给出了归一化的角向和径向波函数,同时获得了能谱方程.     

The radio structure of BL Lac object S5 2007+777

BL Lac object S5 2007+777 has been classified as a HYMOR (Hybrid Morphology radio source) for its hybrid FR I and FR II radio morphology. It is one of four BL Lac objects with a kpc scale extended X-ray jet. In this paper, we searched the unpublished European VLBI Network (EVN) archived high resolution data for this source, and present the high resolution radio structure. The EVN images all show a core-jet structure in 1.6, 5 and 8 GHz. In combination with the VLA data in the literature, we found position angle differences (ΔPA) of about 10°–20° between pc and kpc scale jet structures. The brightness temperature estimated from multi-band EVN images are around 10^11.2–10^11.8 K, from which the Doppler factor ranges from 3.2 to 12.0. We found significant flux variations of the radio core in 1.6 and 5 GHz, from which we derived the variability in brightness temperature T _var to be 10^13.6 K and 10^14.0 K, corresponding to the Doppler factors of 9.3 and 12.4, respectively.

     

A class of nonlinear integrodifferential impulsive periodic systems of mixed type and optimal controls on Banach space

A class of nonlinear integrodifferential impulsive periodic systems of mixed type on Banach space is considered. Existence of periodic PC-mild solutions is proved. Existence of periodic optimal pairs of systems governed by nonlinear impulsive integrodifferential equations of mixed type is also presented. An example is given for demonstration.     

对于自共振激光加速器中轴向场问题的讨论

从洛仑兹力方程的旋量形式出发，讨论了电磁场中电荷运动的轴向电场和轴向磁场问题以及平面波的脉冲和Larmor功率。这些问题是研究自共振激光加速器的基础。From the spinorial form of the Lorentz force equation, the problems about axial electric field and axial magnetic field of charge motion in electromagnetic fields, as well as plane wave pulse and Larmor power have been discussed in this paper. These problems are the foundation of studying the autoresonance laser accelerator (ALA).     

向量优化问题有效解的稳定性

运用标量化的方法,通过锥正定真有效解的上半连续性讨论了无限维赋范空间中锥有效解的部分上半连续性,证明了锥有效解的通有稳定性.在此基础上,进一步证明,在Baire纲的意义下,绝大多数的向量优化问题至少存在一个锥正定真有效解是本质的有效解,换句话说,绝大多数的向量优化问题锥有效解是几乎下半连续的.     

Calcium sulphate hemihydrate hydration leading to gypsum crystallization

The hydration of calcium sulphate hemihydrate (CaSO₄·0.5H₂O) leading to the crystallization of gypsum (calcium sulphate dihydrate – CaSO₄·2H₂O) has been the subject of several investigations over a long period and a vast amount of data is widely distributed throughout in the literature. In this review article an overall picture of the subject is presented. The properties of the two hemihydrates (α- and β-), their hydration characteristics, the mechanism of their hydration and the crystal growth of gypsum are discussed. Additives modify the microstructures of the hardened gypsum and reduce its strength. A probable mechanism is discussed.     

Antimicrobial activity of collagen material with thymol addition for potential application as wound dressing

Recently, special attention has been paid to the development of active wound dressing materials based on biopolymers. Collagen is a natural polymer, which meets the requirements of modern materials for medical applications. However, despite its unique properties, collagen has no antimicrobial activity. In this work thymol was incorporated into collagen films to meet antimicrobial properties of the material. Thymol is a naturally occurring phenolic compound recognized as an antimicrobial agent. Collagen/thymol thin films were obtained through solvent evaporation using collagen solutions containing different amounts of thymol. The structure of the obtained materials was studied using FTIR-ATR spectroscopy. The inhibition ability on the growth of several strains of microorganisms was tested. The standard ISO 22196:2007 was used to define the bactericidal properties of the material. The growth of the following bacteria on the collagen/thymol films was studied: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Enterobacter aerogenes, Candida albicans. The results showed that the growth of Staphylococcus aureus was the most inhibited compared to the other tested strains. Collagen/thymol material is more efficient against pathogens through direct contact compared to the diffusion of thymol from the material. In general, the thymol addition inhibits biofilm formation on the collagen surface.     

Morphological,rheological, crystalline and mechanical properties of ethylene-vinyl acetate copolymer/linear low-density polyethylene/amphiphilic graphene oxide nanocomposites

Chemical modification of graphene oxide has become a popular method for imparting unique properties to extend its application. Here, we show a simple way to synthesize amphiphilic graphene oxide (AGO) by grafting quaternary ammonium salt onto GO sheets. The AGO sheets not only showed high thermal stability and good dispersion in many polar and non-polar solvents in comparison to GO sheets but also the chemical modification maintained the two-dimensional structure. As a result, the AGO sheets improve the interfacial interaction between ethylene-vinyl acetate copolymer (EVA) and linear low-density polyethylene (LLDPE). Because of the large size of AGO, the location of AGO is very dependent on the mixing strategy. The AGO was dispersed in the EVA phase when AGO was mixed first with EVA and then with LLDPE, whereas it was confined in the LLDPE phase when AGO was mixed first with LLDPE and then with EVA. AGO sheets were found at the interface of LLDPE and EVA when AGO, EVA, and LLDPE were mixed together, suggesting that AGO has a high interfacial interaction with both LLDPE and EVA. These high interfacial interactions lead to high tensile strength, Young's modulus, complex viscosity and crystallization temperature in comparison to the EVA/LLDPE blends without AGO sheets.