Epidemic spreading in a finite-precision BA model

The Barabasi-Albert (BA) model with finite-precision preferential attachment is used to build a wide range of network structures. Spreading epidemics and collective dynamics are investigated on such complex networks. Numerical simulations reveal a transition from an exponential scaling to a power-law distribution of link numbers per node along with the increase of the tuning parameter ω. The collective synchronization induced by the Susceptible-Infected-Recovered-Susceptible (SIRS) epidemiological process is shown to depend on the topological structure of the network.     

Mitigation strategies on scale-free networks against cascading failures

According to the dynamic characteristics of the cascading propagation, we introduce a mitigation mechanism and propose four mitigation methods on four types of nodes. By the normalized average avalanche size and a new measure, we demonstrate the efficiencies of the mitigation strategies on enhancing the robustness of scale-free networks against cascading failures and give the order of the effectiveness of the mitigation strategies. Surprisingly, we find that only adopting once mitigation mechanism on a small part of the overload nodes can dramatically improve the robustness of scale-free networks. In addition, we also show by numerical simulations that the optimal mitigation method strongly depends on the total capacities of all nodes in a network and the distribution of the load in the cascading model. Therefore, according to the protection strength for scale-free networks, by the distribution of the load and the protection price of networks, we can reasonably select how many nodes and which mitigation method to efficiently protect scale-free networks at the lower price. These findings may be very useful for avoiding various cascading-failure-induced disasters in the real world and for leading to insights into the mitigation of cascading failures.     

真题真做：提高学士学位论文质量的关键环节

学士学位论文是应用型人才培养的重要环节。欲提高学士学位论文质量，一要以“应用性”为基点，精一fl,设计，选好“真题”；二要以“实践性”为重点，周密安排，落实“真做”；三要以“规范性”为参照，细心修改，写好文章；四要以“科学性”为依据，搞好答辩，严格评审。     

Design of “smart” segmented polymers by incorporating random copolymers as building blocks

This article is dealing with the design of novel segmented polymers comprising homopolymer and random copolymer building blocks designated as block-random. This type of polymeric materials can be prepared through macromolecular engineering by using controlled polymerization methods. By replacing a homopolymer block with a random one, in block copolymer topologies, further tuning of the copolymer properties can be achieved. The present article highlights the recent developments on block-random segmented macromolecules, bearing building blocks of tunable properties (e.g. thermo-sensitivity (LCST), hydrophobicity) and exhibiting responsive behavior in aqueous environments. Furthermore, preliminary novel results regarding pH-sensitive segmented macromolecules of various topologies, bearing random polyampholyte blocks among others, are also demonstrated and discussed.     

BA模型的数学基础——纪念李国平院士吴新谋教授诞辰100周年

该文基于马氏链的概念和技巧, 给出了BA无标度网络模型稳态度分布存在性的严格证明, 并且从数学上重新推导了度分布的精确解析表达式. 此处所用的方法具有一定的普适性, 适用于更一般的无标度型复杂网络模型.     

衰老叶片叶绿素荧光动力学变化及6-BA延缓衰老的机理研究

观测了离体小麦叶片衰老进程中685nm光诱导荧光动力学的变化,发现曲线的第二峰首先消失,F_v(F_p-F_t)、F_p-F_t和F_v/F_o比值迅速下降,达最大荧光P点的时间缩短。推测衰老叶片中PQ分子数目的减少是光合能力丧失的主要原因。用6-BA处理叶片,阻止了F_v和F_v/F_o比值的下降,与对照相比,衰老第三天仍保持第二峰;此外,核黄素使第二峰消失,而核黄素+BA与BA效果相似;同时叶片衰老时SOD活性的下降和膜脂过氧化作用均被延缓,据此探讨了BA作为自由基清除剂延缓叶片衰老的可能机理。     

BA对大豆子叶培养物器官分化的影响及其与子叶离体时苗龄的关系

苗龄显著影响大豆子叶培养物器官分化的能力,其中３ｄ苗龄子叶的器官分化率最高．ＢＡ促进不定芽和抑制不定根形成的作用没有改变苗龄对子叶器官发生的影响趋势．ＢＡ对器官发生的影响幅度随苗龄而异,表明不同苗龄子叶对ＢＡ的反应不同．子叶器官发生的适宜苗龄和ＢＡ生理影响幅度最大的苗龄是有区别的．     

含PU结构乙丙乳液的性能研究

以醋酸乙烯酯(VAc)与丙烯酸丁酯(BA)为主要原料进行核壳乳液共聚合．在壳聚合阶段，将甲苯二异氰酸酯(TDI)与丙烯酸羟乙酯(2-HEA)反应的预聚物封端后，加入到VAc／BA混合单体中并进行聚合反应，得到了稳定的含PU结构的VAc／BA共聚物乳液．乳液胶膜的耐水性、耐溶剂性和力学性能都有较大的提高．DSC及透射电镜分析结果表明，乳胶粒形成了互穿网络结构。     

掺杂C60的PVK及其共聚物的光电导性能

通过自由基共聚合的方法制备了一系列乙烯基咔唑／丙烯酸丁酯（ＮＶＣ／ＢＡ）的共聚物,发现ＮＶＣ能和ＢＡ进行较好的共聚合反就投料比和共聚产物中的各单元组成比接近。通过ＴＥＭ观察。加入的共聚单体ＢＡ可以大大改善了聚乙烯基咔唑（ＰＶＫ）的成膜性能。也对掺有Ｃ６０的ＰＶＫ的均聚和共取物的光电导性能进行了研究。实验结果表明Ｃ５０的加入可以大大增进ＰＶＫ的光电导性能,并且随着Ｃ６０的增加光电导性能增强;共聚体系