Polymer Composites with Plasma-Treated Fillers

A Large-volume Microwave Plasma (LMP) generator has been used to irradiate mica and ground-wood fibers in inert and active gas environments. Irradiated fillers were subsequently incorporated in a polypropylene matrix at solids levels of 10 and 20%. Calorimetrically measured heats of immersion showed that substantial changes in surface properties of fillers were effected by irradiation in ethylene, ammonia, and similar active gases. These surface changes are reflected In ultimate tensile and elongation properties of composites which show marked improvement over controls based on unirradiated fillers. Although no appreciable response in melt viscosity has been observed, surface treatment of fillers does seem to increase significantly melt elasticity of filled composites. The implications of improved performance motivate a more detailed study of the use potential of LMP in the fomulation of polymer composites.     

阴-非离子表面活性剂复合改性水滑石的表面性质研究

采用十二烷基苯磺酸钠（SDBS）、吐温-80（Tween-80）及两种表面活性剂复合改性镁铝水滑石,得到SDBS-LDHs,Tween-LDHs及SDBS/Tween-LDHs₃种改性水滑石。利用反相气相色谱法（IGC）对样品进行表面性质的研究,定量计算了表面吸附自由能（ΔG₀）和表面能色散组分（γ_s^d）。结果表明,改性材料的ΔG₀与γ_s^d值均比未处理的镁铝水滑石小,其中阴-非离子表面活性剂复合改性后的水滑石的ΔG₀与γ_s^d值最小,说明阴-非离子表面活性剂复合改性水滑石较单一改性水滑石更有利于提高材料的稳定性。此外,各类水滑石的γ_s^d值均随着温度的升高而减小,因此,在制备聚合物/水滑石类材料时,可以利用提高温度来改善其与聚合物的相容性。     

4-十二烷氧基苄胺在纳米金微粒合成中的应用

以新型表面活性剂4-十二烷氧基苄胺(C12OBA)构成的C12OBA/正丁醇/正庚烷/丙醛/HAuCl4(aq)反相微乳液作为微反应器,利用微波辐射加热-丙醛还原法制备了C12OBA包覆金纳米微粒;利用透射电镜、傅立叶变换红外光谱仪及X射线衍射仪分析了产物的微观形貌、化学键合特征、晶体结构;并测定了其紫外-可见吸收光谱.结果显示,表面活性剂C12OBA既可参与形成稳定的反相微乳液,又可作为金纳米微粒的良好保护剂.反相微乳液液滴的微小水核以及C12OBA/金的物质的量之比对纳米金微粒的尺寸和形貌起到良好的控制作用.     

Structural Transitions of Self-Nanoemulsifying Drug Delivery System of Glibenclamide,Carvedilol, and Lovastatin upon Progressive Aqueous Dilution

The dynamics of morphological transition in amphiphillic systems such as self-nanoemulsifying drug delivery system (SNEDDS) has become an increasingly active field of research in colloidal science. The present contribution deals with the morphological transition of selected optimized SNEDDS formulations of glibenclamide, carvedilol, and lovastatin on progressive aqueous dilution using transmission electron microscopy. The study emphasizes the structural aspects of the systems and stresses the effect of aqueous dilution under which the systems transform from water-in-oil (L₂) phase into bicontinuous structure and, finally, in oil-in-water (L₁) nanodroplets.     

A simultaneous approach to inverse source problem by Green's function

In this paper, we consider an inverse source problem of identification of F(t) function in the linear parabolic equation u_t = u_xx + F(t) and u₀(x) function as the initial condition from the measured final data and local boundary data. Based on the optimal control framework by Green's function, we construct Fréchet derivative of Tikhonov functional. The stability of the minimizer is established from the necessary condition. The CG algorithm based on the Fréchet derivative is applied to the inverse problem, and results are presented for a test example. Copyright © 2014 John Wiley & Sons, Ltd.     

An inverse coefficient problem for a quasilinear parabolic equation with periodic boundary and integral overdetermination condition

In this paper, the inverse problem of finding the time‐dependent coefficient of heat capacity together with the solution periodic boundary and integral overdetermination conditions is considered. Under some natural regularity and consistency conditions on the input data, the existence, uniqueness, and continuous dependence upon the data of the solution are shown. Some considerations on the numerical solution for this inverse problem are presented with an example. Copyright © 2014 John Wiley & Sons, Ltd.     

Fast enclosure for the minimum norm least squares solution of the matrix equation AXB = C

Fast algorithms for enclosing the minimum norm least squares solution of the matrix equation AXB = C are proposed. To develop these algorithms, theories for obtaining error bounds of numerical solutions are established. The error bounds obtained by these algorithms are verified in the sense that all the possible rounding errors have been taken into account. Techniques for accelerating the enclosure and obtaining smaller error bounds are introduced. Numerical results show the properties of the proposed algorithms. Copyright © 2015 John Wiley & Sons, Ltd.     

稀疏阈值的超分辨率图像重建

为了解决基于字典学习的超分辨重构算法耗时过长的问题,提出了基于稀疏阈值模型的图像超分辨率重建方法。首先,将联合字典理论与图像块稀疏阈值方法相结合,训练得到高、低分辨率过完备图像字典对。接着,通过稀疏阈值OMP算法对图像特征块进行稀疏表示。然后,通过高分辨率字典重构出初始的超分辨图像。最后,通过改进迭代反投影算法对初始的超分辨图像进行全局优化,从而进一步提高图像重构质量。实验结果表明,超分辨图像重构平均峰值信噪比(PSNR)为30.1 d B,平均结构自相似度(SSIM)为0.937 9,平均计算时间为10.2 s。有效提高了超分辨重构的速度,改善了重构高分辨图像的质量。     

基于语义的软件服务故障自动诊断模型

模仿学习是机器人仿生机制研究的主要内容之一,即通过观察、理解、学习、模仿示教行为实现机器人的仿生特性。基于高斯过程分别表达采集离散示教信号所构成的示教轨迹和含有未知参数策略的模仿轨迹,构建模仿学习方法框架,将概率模型匹配引入到模仿学习中,以KL散度为代价函数比较两种轨迹的概率分布,运用梯度下降法寻求使KL散度最小的最优模仿控制策略,将策略应用于模仿机器人以完成与示教相同的模仿任务。以关节型机器人的机械臂摆动行为模仿为学习任务进行仿真,结果表明基于概率轨迹匹配的模仿学习方法能够实现机械臂摆动行为模仿,学习过程较传统方法简易且学习效果较好。