苯乙烯/N-苯基马来酰亚胺共聚物分子量测定和模型

从内聚能的角度建立了含共聚组成、序列不均匀性的共聚物分子量及分布理论,导出其计算式.将凝胶渗透色谱(GPC)与紫外吸收光谱(UV)和示差折光仪(DR)串接,测定苯乙烯(St)/N-苯基马来酰亚胺(PMI)共聚物的分子量.根据St/PMI共聚合原理,对St-PMI共聚物的分子量进行模型化,该模型能较好地预测引发剂、单体配比、转化率对共聚物分子量的影响.     

乙烯基单体-N-取代马来酰亚胺共聚物玻璃化温度研究

用差示扫描量热仪对乙烯基单体/N-取代马来酰亚胺共聚物的玻璃化温度(T_g)进行测定.研究了共聚物组成、序列结构、乙烯基单体和N-取代马来酰亚胺种类对共聚物T_g的影响.提出了含共聚物组成和序列结构的T_g预测方程,该方程不仅适合于无规共聚物,还适合于具有严重交替倾向的共聚物.     

水存在下二氯二茂钛与取代水杨酸的反应

发现含有二氯二茂钛与取代水杨酸的氯仿溶液在水存在下可以发生反应,由此合成了六个二茂钛衍生物,经元素分析、IR及^1HNMR对基结构进行了表征,并对反应机理进行了探讨。     

具有非凸标量守恒律的解的衰减性

我们研究了具有周期初值数据的标量守恒律的方程的解的大时间行为,在很弱的非线性条件下,我们证明了当时间趋于无穷时其解收敛于一常数,本文的结果改进了以前的结果,因为我们只需在初值数据的平均值处流量是非线性的。     

The N*(1710) contribution to the Θ+ production cross sections in p-p collisions

In this paper we derive the Θ production cross section in high energy proton-proton collisions in the relativistic framework through using effective hadronic couplings. Both the nucleon and N^*(1710) propagations are taken into account in the intermediate states. The one π and one ρ exchange mechanisms are considered and the commonly accepted coupling constants and form factors are used in the calculation. We find that ρ exchange is dominant in these processes and the N^*(1710) propagation in the intermediate state is important,which increases the Θ production cross section by a factor of a few tens at center of mass energy 4GeV.     

Self-organized Criticality in an Earthquake Model on Random Network

A simplified Olami-Feder-Christensen model on a random network has been studied. We propose a new toppling rule — when there is an unstable site toppling, the energy of the site is redistributed to its nearest neighbors randomly not averagely. The simulation results indicate that the model displays self-organized criticality when the system is conservative, and the avalanche size probability distribution of the system obeys finite size scaling. When the system is nonconservative, the model does not display scaling behavior. Simulation results of our model with different nearest neighbors q is also compared, which indicates that the spatial topology does not alter the critical behavior of the system.     

Evolution of Bond-Order-Wave Phase in One-Dimensional Mott Insulators

In this paper, by using the level spectroscopy method and bosonization theory, we discuss the evolution of the bond-order-wave （BOW） phase in a one-dimensional half-filled extended Hubbard model wlth the on-site Coulomb repulsion U as well as the inter-site Coulomb repulsion V and antiferromagnetic exchange J. After clarifying the generic phase diagrams in three limiting cases with one of the parameters being fixed at zero individually, we find that the BOW phase in the U-V phase diagram is initially enlarged as J increases from zero but is eventually suppressed as J increases further in the strong-coupling regime. A three-dimensional phase diagram is suggested where the BOW phase exists in an extended region separated from the spin-density-wave and charge-density-wave phases.     

三步升温法合成阵列碳纳米管

本文使用结构简单的单温炉设备, 以二茂铁/三聚氰胺混合物为原料, 采用独特的三步升温方法于光滑的SiO₂衬底上合成出了大面积的阵列碳纳米管, 并对碳纳米管的形貌和结构进行了研究.     

长江中游地区战国青铜箭镞的锈蚀形态

利用扫描电子显微镜（SEM）、能谱仪（EDS）、显微硬度等分析测试技术从材料科学和物理学的角度对长江中游地区战国晚期占楚墓中出土地的青铜箭镞的锈蚀现象进行了较为全面的研究和分析．发现由于锈蚀程度不同,青铜箭镞的组织结构可分为完全矿化层、过渡层和心部原始材料等3个特征层,其中主要成分为氧化物的完全矿化层的结构最疏松,硬度最低;另外,由于埋藏环境的不同,不同地区的锈蚀分层又有差异．实验还对两种类型的开裂裂纹进行了分析,认为一种裂纹是由矿化层氧化物膨胀引起的剥离开裂,进一步发展形成所谓的“粉状锈”;另一种裂纹是当圆柱形箭镞杆膨胀时,矿化层的塑性差,抗变形能力低而产生的开裂．     

纳米Bi2Sn2O7的微乳液法制备与表征

纳米Bi2Sn2O7的微乳液法制备与表征;纳米;Bi2Sn2O7;微乳液法