两亲性聚合物多孔微球的制备研究

合成了具有悬挂双键的苯乙烯-二乙烯基苯多孔微球,在悬挂双键处接枝甲基丙烯酸甲酯,制成了一系列不同接枝度的两亲性聚合物多孔微球。考察了悬挂双键数量、反应时间等因素对接枝率的影响以及接枝率对微球形貌的影响。实验中通过观测澄清点,有效地控制了反应后期自加速现象对接枝率的影响。在反应时间25 m in时,制得了平均孔径为50 nm的两亲性多孔微球。将该微球用于对化妆品活性组分的负载,对极性物的负载率比接枝前高出2倍。     

计算机信息技术在互联网中的应用探析

探究了计算机信息技术在互联网中的应用。选取2010年1月至2014年1月间出版的有关"计算机信息技术在互联网中的应用"方面的文献资料10篇,进行参考研究。结合互联网技术的发展现状及计算机网络安全问题的发生,阐述了信息技术在互联网中的应用。计算机信息技术在互联网中的应用日益广泛,需依靠技术优势解决各类网络安全问题。     

Synthesis of poly(vinyl propionate) from poly(vinyl alcohol) in nonaqueous medium using ethyl nitrate dimethyl sulfoxide as a catalyst

Poly(vinyl alcohol) (PVA) can be dissolved in a nonaqueous medium in the presence of catalytic concentration of ethyl nitrate dimethyl sulfoxide, C₂H₅ONO₂·DMSO. From the PVA solution, poly(vinyl propionate), PVPR was prepared by the homogeneous esterification of PVA with propionic acid. The ester thus formed contained some unconverted hydroxyl group. The formation of the ester was confirmed by the IR and ¹H‐NMR spectra. The molecular weight of the ester was determined by GPC and intrinsic viscosity (η) was determined by viscometric method. Glass transition temperature, T_g, was obtained from differential scanning calorimetric (DSC) analysis. Thermal stabilities of the ester were checked by thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) analysis. The efficiency of the ester as a flow improver of crude oil was also examined. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5675–5679, 2006     

使用证据累积的文本聚类谱算法

针对谱聚类算法相似度函数设置困难问题,提出了一种使用证据累积的文本聚类谱算法.该算法使用超球K均值算法对文本集进行多次聚类,并将每次得到的划分结果作为判断2个文本是否应该放在一个簇中的证据,由此构建文本的相似度矩阵和正则化拉普拉斯矩阵.在TREC和Reuters文本集上进行了实验,验证了本文算法的有效性,它比层次聚类算法和CLUTO提供的K均值算法更加优越.     

青岛市村镇居民环境意识调查

对青岛市3个村镇的103位村镇居民进行了环境意识调查,调查结果采用均值赋值法进行分析,发现居民对环境知识的实际知晓率不高,且获得环保信息的渠道相对单一,对环保的重要性、紧迫性认识较高、责任感较强,对污水处理有积极的态度,并有71％的被调查者愿意缴纳不超过10元／（月·户）的污水处理费用;被调查居民认为调查表中所列各项污染原因与本村的环境污染关系不大．     

浅谈创建安全和谐的油田矿区交通环境

随着油田矿区交通硬件等设施的改善,五七大道等道路上的交通事故发生率也呈上升态势。由于油田矿区交通事故频繁发生,给很多受害者家庭带来痛苦和不幸,同时也严重影响了油田矿区的和谐和稳定。针对诱发油田矿区道路交通事故频发的原因,从"人、车、路"等方面进行归纳和剖析,对有效遏制油田矿区交通事故的频繁发生,创建安全和谐的油田矿区交通环境进行探讨。     

改进纤维单元及在配筋墙体抗震研究中的应用

为了研究配筋砌块砌体剪力墙的抗震性能,在6个配筋砌块砌体剪力墙物理试验的基础上,研究并提出了一种考虑弹塑性剪切变形的纤维模型.通过按照试验条件所进行的滞回性能数值模拟与物理试验结果的对比,表明应用所改进的纤维模型模拟计算能较好地反应配筋砌块砌体剪力墙滞回性能.分析也表明,在一定条件下普通的纤维模型对于配筋砌块砌体剪力墙滞回性能分析仍是适用的,但应用本文所研究的纤维单元计算结果更好.在此基础上,利用均匀设计法安排数值试验,回归给出了一字型配筋砌块短肢砌体剪力墙滞回性能特征参数的经验公式,建议了此类配筋砌块砌体剪力墙结构弹塑性地震反应分析的滞回规律模型.     

Enhanced liquid spreading due to porosity

A conceptual pore level model (Chem. Eng. Sci. 57 (2002) 3401) of spreading of liquid over internally wet porous particles is applied to explain reported rector level enhancement in wetting of trickle bed reactor (Ind. Eng. Chem. Res. 36 (1997) 5133). It is confirmed that a symbiotic relationship exists between internal and external wetting of porous particles whereby each enhances the other. Further, it is illustrated that liquid spreading in porous solids is driven more by porosity than by contact angle. A major implication of this phenomena is that liquid will spread more on less wettable (but porous) surfaces in comparison to more wettable (but nonporus) surfaces and a reinterpretation of experiments involving spreading of liquid over porous solids is required. On a large scenario, it is hoped that present exercise will be in important step towards explaining the complex reactor level macro phenomena by simple and conceptual pore level micro models.     

有机锡化合物催化剂在有机反应中的应用

有机锡化合物具有独特的催化活性,在聚合、加成、酯化和还原等有机合成反应中广泛应用.本文综述了近十年来有机锡化合物在催化领域里的研究进展.     

PAIDD: a hybrid P2P-based architecture for improving data distribution in social networks

Rapid growth in social networks(SNs)presents a unique scalability challenge for SN operators because of the massive amounts of data distribution among large number of concurrent online users.A request from any user may trigger hundreds of server activities to generate a customized page and which has already become a huge burden.Based on the theoretical model and analytical study considering realistic network scenarios,this article proposes a hybrid P2P-based architecture called PAIDD.PAIDD fulfills effective data distribution primarily through P2P connectivity and social graph among users but with the help of central servers.To increase system efficiency,PAIDD performs optimized content prefetching based on social interactions among users.PAIDD chooses interaction as the criteria because user’s interaction graph is measured to be much smaller than the social graph.Our experiments confirm that PAIDD ensures satisfactory user experience without incurring extensive overhead on clients’network.More importantly,PAIDD can effectively achieve one order of magnitude of load reduction at central servers.