无配重炉顶放散阀

介绍了高炉用新型无配重炉顶放散阀的结构特点和工作原理。此结构已经获得了专利(专利号: ZL200520032435．0)。     

Inside Front Cover: Oxidation Conditions for Octadecyl Trichlorosilane Monolayers on Silicon: A Detailed Atomic Force Microscopy Study of the Effects of Pulse Height and Duration on the Oxidation of the Monolayer and the Underlying Si Substrate (Adv. Funct. Mater. 6/2005)

Schubert and co‐workers have performed a detailed atomic force microscopy study to establish and characterize the oxidation conditions of self‐assembled monolayers of octadecyl trichlorosilane on silicon substrates. The cover image illustrates different examples of surfaces that were structured with different patterning conditions, as reported on p. 938. The graph in the background depicts three observed oxidation regimes depending on applied voltage and oxidation time. In current scanning‐probe nanolithography research, substrates consisting of octadecyl trichlorosilane monolayers on silicon are often used. On one hand, the presence of an organic monolayer can be used as a passive resist, influencing the formation of silicon dioxide on the substrate, whereas in other cases the monolayer itself is patterned, creating local chemical functionality. In this study we investigate the time scales involved in either process. By looking at friction and height images of lines oxidized at different bias voltages and different pulse durations, we have determined the parameter space in which the formation of silicon dioxide is dominant as well as the region in which the oxidation of the monolayer itself is dominant.     

舰载精密光学系统扰动速度的自稳定控制

介绍了具有惯性导航系统的大型舰艇上前馈控制的自稳定方法。分析船摇产生扰动速度, 给出因船摇在方位和俯仰方向产生的附加速度及试验结果;并与速率陀螺自稳定方法进行了对比。     

Shape extraction: A comparative study between neural network-based and conventional techniques

Extraction of the skeletal shape of an elongated object is often required in object recognition and classification problems. Various techniques have so far been developed for this purpose. A comprehensive comparative study is carried out here between neural network-based and conventional techniques. The main problems with the conventional methods are noise sensitivity and rotation dependency. Most of the existing algorithms are sensitive to boundary noise and interior noise. Also, they are mostly rotation dependent, particularly if the angle of rotation is not a multiple of 90°. On the other hand, the neural network based technique discussed here is found to be highly robust in terms of boundary noise as well as interior noise. The neural method produces satisfactory results even for a very low (close to 1) Signal to Noise Ratio (SNR). The algorithm is also found to be efficient in terms of invariance under arbitrary rotations and data reduction. Moreover, unlike the conventional algorithms, it is grid independent. Finally, the neural technique is easily extendible to dot patterns and grey-level patterns also.     

《内燃机学报》自引统计与分析

本文以《内燃机学报》１９９０年～１９９５年６卷２４期３２３篇论文的１８１８条引文为抽样，通过对其部门、语种、期刊、著者、学科和时间的自引统计与分析，对其自引规律进行探讨，以期从自引出发，定量地考察这一学科领域中的著述动态和征兆，并以此来剖析一些科技领域的发展趋势和规律。     

Pores in III–V Semiconductors

The paper reviews electrochemically etched pores in III–V compound semiconductors (GaP, InP, GaAs) with emphasis on nucleation and formation mechanisms, pore geometries and morphologies, and to several instances of self‐organization. Self‐ organization issues include the formation of single‐crystalline two‐dimensional hexagonal arrays of pores with lattice constants as small as 100 nm found in InP, synchronized and unsynchronized diameter oscillations coupled to current and voltage oscillations, and pore domain formation. The findings are discussed in relation to pores observed in silicon. Some novel properties of the porous layers obtained in III–V compounds are briefly described.     

Thermally Stable Two‐Dimensional Hexagonal Mesoporous Nanocrystalline Anatase,Meso‐nc‐TiO2: Bulk and Crack‐Free Thin Film Morphologies

Herein a novel synthetic route is described for the production of thermally stable, structurally well‐defined two‐dimensional (2D) hexagonal mesoporous nanocrystalline anatase (meso‐nc‐TiO₂), with a large pore diameter, narrow pore‐size distribution, high surface area, and robust inorganic walls comprised of nanocrystalline anatase. The synthetic approach involves the evaporation‐induced co‐assembly of a non‐ionic amphiphilic triblock‐copolymer template and titanium tetraethoxide, but with a pivotal change in the main solvent of the system, where the commonly used ethanol is replaced with 1‐butanol. This seemingly minor modification in solvent type from ethanol to 1‐butanol turns out to be the key synthetic strategy for achieving a robust, structurally well‐ordered meso‐nc‐TiO₂ material in the form of either thick or thin films. The beneficial “solvent” effect originates from the higher hydrophobicity of 1‐butanol than ethanol, enhancing microphase separation and templating, lower critical micelle concentration of the template in 1‐butanol, and the ability to increase the relative concentration of the inorganic precursor to template in the co‐assembly synthesis. Moreover, thin films with dimensions of several centimeters that are devoid of cracks down to the length scale of the mesostructure itself, having high porosity, well‐defined mesostructural features, and semi‐crystalline pore walls were straightforwardly and reproducibly obtained as a result of the physicochemical property advantages of 1‐butanol over ethanol within our synthesis scheme.