Co-salen functionalized on graphene as an efficient heterogeneous catalyst for cyclohexene oxidation

Co-salen functionalized on graphene with an average pore size of 27.7 nm as a heterogeneous catalyst exhibited good catalytic activity and recyclability in cyclohexene oxidation.     

预应力预制混合装配双肢墙弹塑性性能

提出了新型预应力预制混合装配双肢墙(PPHCW)结构,推导了PPHCW的整体性系数和肢强系数的计算公式,以DRAIN-2DX软件为分析平台,基于自行开发的5,12号单元,对PPHCW结构的弹塑性性能进行参数分析,包括:肢强系数、整体性系数、连接钢筋面积、预应力筋面积、有效预应力和墙肢纵筋配筋率.结果表明:增加连接钢筋及预应力筋面积,减小有效预应力、墙肢纵筋配筋率和整体性系数可延迟连梁中预应力筋的屈服;随整体性系数、预应力筋和连接钢筋的面积、墙肢纵筋配筋率的增大及肢强系数的减小,结构承载力随之提高;上述参数对结构延性均有影响,但其影响结果与结构的破坏极限状态相关;与整体性系数相比,耦联率可综合反映结构几何尺寸、连梁与墙肢配筋对结构弹塑性性能的影响.     

A communication security protocol of mobile agent system

The security issues of mobile agent system have embarrassed its widespread implementation. The paper analyses communication security threats and countermeasures of mobile agent system and proposes a communication security protocol of mobile agent system. It provides multifactor authentication, encryption transmission, and integrity protection of mobile agent.     

Global attractivity and permanence of a stage-structured pest management SI model with time delay and diseased pest impulsive transmission

In this paper, we consider a stage-structured pest management SI model with time delay and diseased pests impulsive transmission. We obtain the sufficient conditions of the global attractivity of pest-extinction boundary periodic solution and the permanence of the system. We also prove that all solutions of the system are uniformly ultimately bounded. Our results provide a reliable tactic basis for the practice of pest management.     

Polymerization and nanocomposites properties of multifunctional methylmethacrylate POSS

Thermally induced polymerization of multifunctional methylmethacrylate POSS (MMA‐POSS) was studied in this work for preparation of polymer/POSS nanocomposites. The polymerization of MMA‐POSS could be promoted with benzoyl peroxide (BPO). Self‐assembly of POSS into a layer‐by‐layer structure in the MMA‐POSS polymer (TP‐MMA‐POSS) is observed with a transmission electron microscopy. An ultra‐low‐k value of about 1.85 is measured with TP‐MMA‐POSS. In addition, polyimide‐POSS nanocomposites are also prepared. These nanocomposites demonstrate good homogeneity and enhanced mechanical properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5157–5166, 2008     

利用原子层外延方法制备的ZnS:Er3+薄膜的交流电致发光特性

采用原子层外延方法(ALE)制备了ZnS:Er3+交流电致发光(ACEL)薄膜,得到了明亮的绿色EL。发现了随Er3+离子浓度增加,对应于4F9/2→4I15/2跃迁的谱线强度增加甚至超过2H11/2→4I15/2跃迁的谱线强度。通过对EL衰减的分析,发现了绿红比随外加电压的变化关系以及EL光谱与温度的关系。在Er3+离子浓度较高时,Er3+离子之间发生明显的能量传递。提出了Er3+离子间的交叉驰豫模型并计算了交叉弛豫速率,同拟合衰减曲线得到的值相比,两者符合得较好。     

关于地暖供热优势的探讨

地暖被认为是一种理想的供暖方式.文章通过对我国地暖供热现状的分析及应用实例介绍,阐明了对地面辐射采暖舒适性、节能性的看法.     

A nonlinear parameter dependent boundary value problem in one space dimension

No abstract. March 30, 2000     

TBP萃取一元有机酸的研究

考察了不同稀释剂中ＴＢＰ对甲酸、乙酸、丙酸、丁酸、氯乙酸、二氯乙酸、三氯乙酸等一元有机酸的萃取．探讨了被萃取物结构与萃取性能的关系及稀释剂性质和温度对萃取的影响．用红外光谱对萃取机理进行了研究．正辛烷中不同有机酸的萃取顺序为，①三氯乙酸＞二氯乙酸＞氯乙酸＞乙酸，萃取平衡常数随有机酸的取代基诱导常数σ＊的增大而增大，两者间遵从Ｔａｆｔ线性关系，诱导效应是影响萃取的主要因素．②丁酸＞丙酸＞乙酸＞甲酸，随诱导效应减弱和空间效应增大，萃取能力增强，表明空腔效应起主要作用．