8Mbps数字电视编解码器系统

本文出了８Ｍｂｐｓ数字电视编解码器的硬件实现方案，包括视频、音频信道三个部分，同时给出了样机的测试结果，最后略地介绍了此编解码器的应用情况。     

磁控溅射法制备的高反Ag_5In_5Te_(47)Sb_(33)相变薄膜的光谱性质及短波长静态记录性能

研究了磁控溅射制备的Ａｇ５Ｉｎ５Ｔｅ４７Ｓｂ３３相变薄膜的光谱及短波长静态记录性能。研究结果表明，晶态薄膜反射率较高，并在６００～９００ｎｍ波长范围内，晶态与非晶态的反射率和折射率相差很大。在ＣＤ－Ｅ系统的工作波长７８０ｎｍ处，晶态反射率高达５０％，光学常数为５．３４－１．０ｉ；非晶态反射率为２３％，光学常数为２．５－１．０３ｉ。从这一角度讲，Ａｇ５Ｉｎ５Ｔｅ４７Ｓｂ３３相变薄膜适于做ＣＤ－Ｅ系统的记录介质。另外，采用波长为５１４．４ｎｍ的短波长光学静态记录测试仪对Ａｇ５Ｉｎ５Ｔｅ４７Ｓｂ３３薄膜的记录性能进行了测试，结果表明，这种薄膜短波长记录性能较好，它在较低功率和短脉宽的激光束作用下就可得到较高的反射率对比度。     

Interfacial crack between elastic half-spaces under harmonic loading

A system of boundary integral equations that allows evaluating the displacement and stress fields for an interfacial crack under harmonic loading is presented. Expressions for the integral kernels are obtained. A numerical solution for a penny-shaped crack between steel and aluminum half-spaces under normally incident compression-rarefaction wave is given __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 8, pp. 47–56, July 2007.     

Unmasking the Action of Phosphinous Acid Ligands in Nitrile Hydration Reactions Catalyzed by Arene–Ruthenium(II) Complexes

The catalytic hydration of benzonitrile and acetonitrile has been studied by employing different arene–ruthenium(II) complexes with phosphinous (PR₂OH) and phosphorous acid (P(OR)₂OH) ligands as catalysts. Marked differences in activity were found, depending on the nature of both the P‐donor and η⁶‐coordinated arene ligand. Faster transformations were always observed with the phosphinous acids. DFT computations unveiled the intriguing mechanism of acetonitrile hydration catalyzed by these arene–ruthenium(II) complexes. The process starts with attack on the nitrile carbon atom of the hydroxyl group of the P‐donor ligand instead of on a solvent water molecule, as previously suggested. The experimental results presented herein for acetonitrile and benzonitrile hydration catalyzed by different arene–ruthenium(II) complexes could be rationalized in terms of such a mechanism.     

Methane adsorption on microporous carbon adsorbent with wide pore size distribution

Methane adsorption on a microporous carbon adsorbent with a bimodal pore size distribution is studied at temperatures of 303–333 K at pressures up to 30 MPa. The total micropore volume of the adsorbent, as determined by the Dubinin method, is as large as 1.02 cm³/g. Maximum values of methane adsorption of ≈18 mmol/g are attained at a temperature of 303 K and a pressure of 30 MPa. Methane adsorption isosteres are plotted based on experimental data, and adsorption equilibria at low temperatures are calculated using the linearity of the plots. Experimental isotherms of methane adsorption are compared with the isotherms calculated by the Dubinin–Nikolaev equation with variations in parameters E and n. Temperature dependences of these parameters are determined. Specific characteristics of methane adsorption accumulation are calculated.     

反常磁矩对弱磁场弱相互作用费米气体热力学性质的影响

考虑费米子的反常磁矩, 运用赝势法和热力学理论, 导出弱磁场中弱相互作用费米气体自由能的解析式, 以此为基础给出高温和低温情况下系统热力学性质, 分析反常磁矩对热力学性质的影响机理. 研究表明: 反常磁矩对热力学性质的影响与温度相关, 而且这种影响随温度的上升在低温区是增大的, 在高温区是减小的; 对于系统的化学势、内能, 反常磁矩加强了磁场的影响, 弱化了相互作用的影响; 对于系统的热容量, 反常磁矩在低温区使其减小, 在高温区使其增加.     

Counterion exchange to achieve reversibly switchable hydrophobicity and oleophobicity on fabrics

We describe a simple layer-by-layer (LbL) technology and counterion exchange procedure to tune the liquid wettability of commercially available cotton fabrics. A polyelectrolyte multilayer is deposited on the fabric surface by the LbL technology, and counterion exchange is used to control the surface composition and thereby to modulate the solid surface energy. The tunability of the solid surface energy, along with the inherent re-entrant texture of the cotton fabric, results in simultaneously switchable wettability between a nonwetting state and a fully wetted state for water and hexadecane. This switchable hydrophobicity and oleophobicity can be explained within a robustness factor, which is a quantitative criterion for the transition between the two states. The counterion exchange can be confirmed by X-ray photoelectron spectroscopy analysis.