聚膦腈-g-聚己内酯共聚物的合成与表征

通过三甲基碘硅烷与聚二(2-甲氧基乙氧基)膦腈侧链上的醚键反应后水解得到侧链含部分羟基的聚膦腈,然后利用聚膦腈的侧链羟基在异辛酸亚锡催化作用下,引发己内酯单体开环聚合制备了聚膦腈-g-聚己内酯共聚物.该共聚物中聚己内酯链段的接枝率和侧链长度可通过改变三甲基碘硅烷和己内酯单体的投料来控制.     

基于移动社交网络的谣言传播动力学研究

本文在CSR传播模型的基础上提出基于移动社交网络的CSR的谣言传播模型. 改进了CSR模型的传播规则和传播动力学方程, 使得更符合移动SNS上用户的使用习惯. 在CSR模型中的接受概率数学模型基础上, 考虑个人接受阈值对接受概率的影响, 更符合人类接受谣言的心理学特点. 本文对该传播模型进行了理论分析. 并在仿真实验中, 利用多agent仿真平台对新模型和CSR模型以及SIR模型 在匀质网络和异质网络中的传播效果进行了对比研究, 从实验的结果来看, 新的谣言传播模型在匀质网络中传播范围更广, 传播速度更快. 新模型具有初值敏感性的特点. 关键词： 复杂网络 移动社交网络 谣言传播     

取代-3-甲酰色酮与(硫代)巴比妥酸的固相缩合反应

在无溶剂无催化剂条件下,取代-3-甲酰色酮与(硫代)巴比妥酸通过固相Knoevenagel缩合反应合成了一系列5-(取代色酮基-3-亚甲基)(硫代)巴比妥酸,收率68.0%～85.5%,其结构经1H NMR确证.     

一个小型的计算机网络计划编制系统

本文介绍一个小型的计算机网络计划编制系统应具备的功能，以及计算机网络计划编制的方法与步骤。     

聚磷腈改性及其生物医学应用

聚磷腈是一种具有良好侧基功能化特性的高分子,通过接入不同侧基的聚磷腈与其它聚合物共混共聚,可以制备出具有不同性能的材料。本文介绍了目前关于国内外聚磷腈共混共聚的研究现状,并对聚磷腈改性在生物医学领域的应用及进展作了简要的介绍。     

Fast local reconstruction by selective backprojection for low dose in dental computed tomography

The high radiation dose in computed tomography （CT） scans increases the lifetime risk of cancer, which becomes a major clinical concern. The backprojection-filtration （BPF） algorithm could reduce the radiation dose by reconstructing the images from truncated data in a short scan. In a dental CT, it could reduce the radiation dose for the teeth by using the projection acquired in a short scan, and could avoid irradiation to the other part by using truncated projection. However, the limit of integration for backprojection varies per PI-line, resulting in low calculation efficiency and poor parallel performance. Recently, a tent BPF has been proposed to improve the calculation efficiency by rearranging the projection. However, the memory-consuming data rebinning process is included. Accordingly, the selective BPF （S-BPF） algorithm is proposed in this paper. In this algorithm, the derivative of the projection is backprojected to the points whose x coordinate is less than that of the source focal spot to obtain the differentiated backprojection. The finite Hilbert inverse is then applied to each PI-line segment. S-BPF avoids the influence of the variable limit of integration by selective backprojection without additional time cost or memory cost. The simulation experiment and the real experiment demonstrated the higher reconstruction efficiency of S-BPF.     

Tunable optical filter using second-order micro-ring resonator

In this paper, we design and fabricate a silicon integrated optical filter consisting of two cascaded micro-ring resonators and two straight waveguides. Two micro-heaters are fabricated on the top of two micro-rings respectively, which are employed to modulate the micro-rings to perform the function of a tunable optical filter by the thermo–optic effect. The static response test indicates that the extinction ratio and 3-d B bandwidth are 29.01 d B and 0.21 nm respectively, the dynamic response test indicates that the 10%–90% rise and 90%–10% fall time of the filter are 16 μs and 12 μs, respectively,which can meet the requirements of optical communication and information processing. Finally, the power consumption of the device is also characterized, and the total power consumption is about 9.43 m W/nm, which has been improved efficiently.     

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在分析典型工作任务的基础上,以力学知识的应用为中心,以训练学生的能力为重 点,以行动为学习过程,从课程目标、课程内容、教学情境、学习资源和自主学 习5个方面,介绍了工程力学课程教学设计思路和具体做法.     

双响应性嵌段共聚物聚异丙基丙烯酰胺-b-聚(L-谷氨酸)的合成与表征

通过组合可逆加成-断裂链转移自由基聚合(RAFT)和氨基酸可控开环聚合(ROP)两种方法,合成得到聚异丙基丙烯酰胺-b-聚(L-谷氨酸)嵌段共聚物(PNIPAAm55-b-PLGA35).以5-氨基戊醇、12-硫醇等为原料,合成了新型的芴甲氧基保护的三硫酯链转移剂.使用核磁氢谱、凝胶排阻色谱对产物进行验证.并通过紫外-可见分光光度法、透射电镜、动态光散射表征,证明了该嵌段共聚物具有刺激响应性的胶束化行为.     

芳香硝基化合物的能量分辨质谱

本文报道用ＭＳ／ＭＳ技术的一种重要实验方法——能量分辨质谱（ＥＲＭＳ）来鉴别质谱分析中的同分异构体化合物。系统探讨了同分异构的硝基芳香化合物２，３－ＤＮＴ和３，５－ＤＮＴ（相对分子质量为１８２）在电子轰击（ＥＩ）方式下，裂分途径与其分子内能的相互关系以及离子的结构和裂分途径相对于碰撞能量（ＣＥ）的依赖关系（裂分曲线）。结果表明，利用同分异构化合物在能量分辨中的显著差异可以辨别它们的结构