基于校园网的网络安全与开销研究

校园网已经成为学校师生学习工作的重要平台,与此同时校园网是电脑病毒和僵尸网络的多发区。在校园网安全与安全开销之间建立必要的平衡关系,可以促进校园网应用的顺利实施。通过调查研究,寻找影响校园网安全的主要因素及其对应的安全开销,对校园网中的不安全因素进行分析,力求在应用与安全之间建立平衡,并在校园网中进行有效性分析,分析结果表明该种策略可用性较好,有一定推广价值。     

Effects of the reinforcement and toughening of acrylate resin/CaCO3 nanoparticles on rigid poly(vinyl chloride)

Novel composite particles based on nanoscale calcium carbonate (nano‐CaCO₃) as the core and polyacrylates as the shell were first synthesized by in situ encapsulating emulsion polymerization in the presence of the fresh slush pulp of calcium carbonate (CaCO₃) nanoparticles. Subsequently, these modified nanoparticles were compounded with rigid poly(vinyl chloride) (RPVC) to prepare RPVC/CaCO₃ nanocomposites. At the same time, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were investigated, and the synergistic effect of modified nanoparticles with chlorinated polyethylene (CPE) was also studied. The results showed that in the presence of nano‐CaCO₃ particles, the in situ emulsion polymerization of acrylates was carried out smoothly, and polyacrylates successfully encapsulated on the surface of nano‐CaCO₃ to prepare the modified nanoparticles, breaking down nano‐CaCO₃ particle agglomerates, improving their dispersion in the matrix, and also increasing the particle–matrix interfacial adhesion. Thus, the effects of the reinforcement and toughening of these modified nanoparticles on RPVC were very significant, and the cooperative effect of the nanoparticles with CPE occurred in the united modification system. Scanning electron microscopy analyses indicated that large‐fiber drawing and network morphologies coexisted in the system of joint modification of nanoparticles with CPE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3940–3949, 2007     

Preparation of Narrow or Monodisperse Polymer Microspheres with Cyano Group by Distillation-Precipitation Polymerization

Summary Narrow- or monodisperse poly(divinylbenzene-co-acrylonitrile) (poly(DVB-co-AN)) microspheres with reactive cyano group were prepared by distillation-precipitation polymerization of divinylbenzene (DVB) and acrylonitrile (AN) in neat acetonitrile with 2,2′-azobis(isobutyronitrile) (AIBN) as initiator in the absence of any stabilizer or additive without stirring. The effects of the comonomer feed on the morphology and the size of poly(DVB-co-AN) microspheres were investigated. All the polymer microspheres were characterized with scanning electron microscopy and FT-IR spectra.     

A Normalization Method of Moment Invariants for 3D Objects on Different Manifolds

3D objects can be stored in computer of different describing ways, such as point set, polyline, polygonal surface and Euclidean distance map. Moment invariants of different orders may have the different magnitude. A method for normalizing moments of 3D objects is proposed, which can set the values of moments of different orders roughly in the same range and be applied to different 3D data formats universally. Then accurate computation of moments for several objects is presented and experiments show that this kind of normalization is very useful for moment invariants in 3D objects analysis and recognition.     

Electropolymerization and ion exchange properties of a polypyrrole film doped by para‐toluene sulfonate

Electropolymerization and ion exchange properties of the polypyrrole film doped by para‐toluene sulfonate (PPy/pTS) were investigated in aqueous solutions. The film with a column‐like surface morphology was galvanostatically synthesized at 3 mA/cm² during 1800 s. Cyclic voltammetric measurements of the PPy/pTS film in sodium para‐toluene sulfonate (NapTS), tetraethylammonium chloride ((C₂H₅)₄NCl), and NaCl aqueous solutions showed a cation exchange property, an anion exchange property, and a combination of them, respectively. Moreover, the large ions could decrease the transport of the small ions coexisting in the same solution, and the redox processes were proved to be electrochemically irreversible and ion transport‐limiting reactions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2518–2522, 2006     

石英陶瓷注凝成型影响因素的研究

介绍了熔融石英陶瓷的注凝成型机理及其工艺过程,分析讨论了影响熔融石英陶瓷注凝成型的主要因素,通过研究确定了合理的制备工艺参数.     

水性UV图案化功能涂膜技术研究

研究了一种新型水性UV涂料制备技术,可得到用传统方法无法获得的图案化涂膜。利用扫描电镜、DSC、凝胶渗透色谱等对该图案化聚合物进行分析表征;考察了不同功能添加剂对涂膜形貌的影响;并讨论了光照时间、光引发剂用量与聚合物相对分子质量间的关系。     

自含砷合碳难处理金矿中提取金的研究─Ⅰ.氨水脱砷-石灰加压氧化-氰化

针对甘肃省坪定金矿含金、砷高、金部分地赋存于脉石、脉石为碱性、属于难选难冶矿的特点，提出了氨水脱砷－石灰加压氧化－氰化新工艺．当原矿含金8．7g／t及13．0％砷时，砷可脱除95％，金可浸出85％．技术及经济指标预计均较满意．     

一种汉语方言编码与转换机制的研究

回顾了汉语拼音方案的组成和特点,分析了方言编码的可行性。引入二进制编码方式对汉字发音进行编码。编码序列包括了声母、韵母、音调、儿化音等编码部分。建立了方言音、修饰音、标准音之间的转换关系。以湘汨地区的方言为例,详细论述了方言编码和转换的过程。以人工代谢算法作为寻优策略,结合特定语言环境,将方言音转换成标准音。通过实例分析论述了该方案的可行性和合理性。     

Ozone-Based Advanced Oxidation Processes for the Decomposition of N-Methyl-2-Pyrolidone in Aqueous Medium

The present study investigates the decomposition of N-Methyl-2-Pyrolidone (NMP) using conventional ozonation (O₃), ozonation in the presence of UV light (UV/O₃), hydrogen peroxide (O₃/H₂O₂), and UV/H₂O₂ processes under various experimental conditions. The influence of solution pH, ozone gas flow dosage, and H₂O₂ dosage on the degradation of NMP was studied. All ozone-based advanced oxidation processes (AOPs) were efficient in alkaline medium, whereas the UV/H₂O₂ process was efficient in acidic medium. Increasing ozone gas flow dosage would accelerate the degradation of NMP up to certain level beyond which no positive effect was observed in ozonation as well as UV light enhanced ozonation processes. Hydrogen peroxide dosage strongly influenced the degradation of NMP and a hydrogen peroxide dosage of 0.75 g/L and 0.5 g/L was found to be the optimum dosage in UV/H₂O₂ and O₃/H₂O₂ processes, respectively. The UV/O₃ process was most efficient in TOC removal. Overall it can be concluded that ozonation and ozone-based AOPs are promising processes for an efficient removal of NMP in wastewater.