α－Al_2O_3衬底上生长的GaN膜的光学性质

采用金属有机化学气相淀积（ＭＯＣＶＤ）方法生长了α－Ａｌ２Ｏ３衬底上外延的高质量的单晶ＧａＮ薄膜。Ｘ射线衍射光谱与喇曼散射光谱表征了ＧａＮ外延薄膜的单晶结构和单晶质量。透射光谱和光调制反射光谱定出了六角单晶ＧａＮ薄膜的直接带隙宽度和光学参数。     

Efficient design of SIW filters with knowledge‐embedded space mapping technique

This article presents an optimization technique for the design of substrate‐integrated waveguide (SIW) filters using knowledge‐embedded space mapping. An effective coarse model is proposed to represent the SIW filter. The proposed coarse model can be analyzed in the available commercial software ADS. The embedded knowledge includes not only formulas but also extracted design curves, which help to build the mapping between the coarse and fine models. The effectiveness of the proposed method is demonstrated through a design example of a six‐pole SIW filter. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

不同基质配比对银毛野牡丹扦插的影响

银毛野牡丹是优良的园林观赏性植物,但是繁殖有性结实率低。通过为期30天的扦插试验,对比不同基质（原土、草炭土、蛭石、珍珠岩）配比对银毛野牡丹插穗生长的影响,分析插穗生根时间、生根数目、最长根长、生根率、生长状态以及基质变化,找出适合其生长发育的优良基质,为银毛野牡丹的繁殖提供技术支撑。研究表明：试验组T8（原土：细沙：草炭土：蛭石：珍珠岩=1：1：2：1：1）的插穗生根率、最长根长、插穗长势为最佳,试验组T2（草炭土）效果次之,在条件有限的情况下可以作为备用方案以供生产所需。     

CoCrPtNb／CrTi／C多层膜记录介质的制备和性能研究

采用CoCrPtNb四元合金作磁记录介质，并采用多层膜结构（CoCrPt）100-Nbx/CrTi／C／Glass制备玻璃盘基硬盘。实验结果表明：采用适宜厚度的籽晶层与合适组分的底层和磁性层的多层膜结构，即使在室温下溅射，此种薄膜磁记录介质也可得到高达260kA／m的矫顽力；在550℃高温下，经过30min真空退火后，其矫顽力有较大幅度提高，并在Nb含量为2．4％（原子分数）时达到极大值386kA／m，适用于高密度磁记录。同时，也详细分析了磁性层和底层组分、籽晶层厚度以及真空退火对磁记录介质磁性能和微结构的影响。     

PKA国家参考品的制备

本文应用 PKA 微量滴定板方法,用 WHO1984年建立的 PKA 国际标准品进行标定,制备了我国第一批 PKA 国家参考品。     

Particle-Substrate Collisions, Particle Rebound and Removal

Recent progress in particle capture and rebound and its effect on the adhesion force is reviewed in this paper. Particles rebound when the incident velocity is greater than a characteristic critical velocity. Lower impaction velocity particles experience elastic and plastic deformation. Recent models for particle rebound and capture are discussed and evaluated in terms of their restrictive assumptions and results. Recent experimental data of particle rebound and capture is also discussed, as is the hydrodynamic removal of captured particles. The removal of particles occurs when the applied hydrodynamic removal force overcomes the adhesion force. The effect of adhesion-induced deformation on the removal of particles is introduced and discussed.     

Decision support in machine vision system for monitoring of TFT-LCD glass substrates manufacturing

This study addresses classification methodology for the automatic inspection of a range of defects on the surface of glass substrates in thin film transistor liquid crystal display glass substrate manufacturing. The proposed methodology consisted of four stages: (1) feature extraction by calculating the wavelet co-occurrence signature from the substrate images, (2) handling of imbalanced dataset using the Synthetic Minority Over-sampling TEchnique (SMOTE), (3) reduction of the feature's dimension by principal component analysis, and (4) finally choosing the best classifier between three different methods: Classification And Regression Tree (CART), Multi-Layer Perceptron (MLP) and Support Vector Machine (SVM). In training the SVM and MLP classifiers, the simulated annealing algorithm was used to obtain the optimal tuning parameters for the classifiers. From the industrial case study, the proposed feature extraction algorithm could remove the defect-irrelevant image features and SMOTE increased the accuracy of all three methods. Furthermore, the optimized SVM and MLP models were more accurate than the CART model whereas a higher accuracy of 89.5% was observed for the proposed SVM model.     

聚碳酸酯光学性能应用及改进研究进展

概述了光学级聚碳酸酯结构与光学性能的关系和其在光学领域的应用,对其光学异向性产生的原因进行了讨论,并对改善聚碳酸酯光学异向性的途径进行了归纳,通过采用共聚、共混方法可使聚碳酸酯的双折射得到有效的降低。     

Surface modification of macroporous Al2O3 tubes with carbon-doped TiO2 intermediate layer and preparation of highly permeable palladium composite membranes for hydrogen separation

ABSTRACT

To prepare H₂-permeable palladium composite membranes, a novel carbon-doped microporous TiO₂ intermediate layer was introduced to modify the surface of macroporous Al₂O₃ substrates. The Pd/TiO₂–C/Al₂O₃ membrane was prepared via electroless plating, and thereafter, carbon residue in the intermediate layer was removed by calcination in air, yielding a Pd/TiO₂/Al₂O₃ membrane. Experimental results indicate that the carbon residue shrinks the pore size of the intermediate layer and facilitates a decrease of membrane defects. Additionally, carbon removal induces a higher effective membrane area at the permeate side, which enhances hydrogen permeability. Furthermore, the apparent activation energy (E_A) and stability of the as-prepared Pd/TiO₂/Al₂O₃ membrane were investigated.     

Electrodeposition of smooth and adherent film of polypyrrole on lead electrode

Electropolymerization of pyrrole on lead substrate electrode was studied. Due to electrochemical activity of Pb in acidic media, this process is only possible at basic pHs. For this purpose, electropolymerization process was performed in an aqueous solution of Na₂SO₄ with pH 12. Potentiodynamic cycling shows the Pb oxidation at the first cycles. In subsequent cycles, polypyrrole film grows on the oxidized lead substrate. Of course, as the passive film is highly porous, a composite of polypyrrole/PbSO₄ is formed in the first layers. However, subsequent cycling leads to the formation of pure polypyrrole film. According to this structure and strong connection of the polymer film to the substrate surface via this composite layer, the polypyrrole film deposited on the lead surface has enhanced mechanical stability. AFM measurements showed peculiar smoothness of both composite and lateral polypyrrole films. This synthesis approach is of particular interest for the preparation of highly stable polymer films and fabrication of supercapacitors with a polymer/PbSO₄ conductive structure.