高效液相色谱法在二氨基二苯甲烷四缩水甘油醚树脂合成中的应用

采用高效液相色谱法跟踪了二氨基二苯甲烷四缩水甘油醚环氧树脂的合成反应,对中间产物进行定性分析并观察其在反应过程中的变化,分析了反应条件对产品的影响。结果表明,合成反应的关键在于开环反应的第一步,通过控制第一步反应的温度及时间,可以得到环氧值为０．７０～０．９０环氧当量／１００ｇ的树脂产品。     

Network evolution driven by dynamics applied to graph coloring

An evolutionary network driven by dynamics is studied and applied to the graph coloring problem. From an initial structure, both the topology and the coupling weights evolve according to the dynamics. On the other hand, the dynamics of the network are determined by the topology and the coupling weights, so an interesting structure-dynamics co-evolutionary scheme appears. By providing two evolutionary strategies, a network described by the complement of a graph will evolve into several clusters of nodes according to their dynamics. The nodes in each cluster can be assigned the same color and nodes in different clusters assigned different colors. In this way, a co-evolution phenomenon is applied to the graph coloring problem. The proposed scheme is tested on several benchmark graphs for graph coloring.     

纳米WO3的制备工艺探讨与结构表征

通过气液反应制备了纳米WO₃光催化剂,并用紫外吸收光谱、粉末X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、能量散射谱(EDS)等手段对催化剂进行了表征.讨论了乙二醇加入量和表面活性剂十二烷基苯磺酸钠对催化剂粒度大小和形貌的影响.结果表明:当水和乙二醇的比例为25:75时所得WO₃粒径为30 nm左右.在此比例条件下加入0.1 g表面活性剂十二烷基苯磺酸钠,可制得片状WO₃,粒径约为80 nm.对自制的两种纳米WO₃光催化剂在紫外光照射时降解苯酚的活性进行了初步探讨,两者的催化性能均明显优于商品WO₃.