Chitosan-Based Zwitterionic Polyelectrolytes and Their N-Phosphobetainates: Facile Synthesis and Aqueous Solution Behaviors

1Introduction Chitosan has remarkable potential applications in pharmaceutical and cosmetic formulations[1], e.g. for drug delivery systems, tissue engineering, transplant and cell regeneration due to its excellent biocompatibility, biodegradability, mucoadhesion, etc. Its major drawback as considered for pharmaceutical and cosmetic formulations is its poor solubility due to strong hydrogen bonding and compact structures. Considerable efforts were focused on improving its solubility and enforcing its functionality[1]. As well-known that phosphorylcholine (PC), the structural component of cell membrane, is an amphiphile containing the zwitterionic quaternary ammonium and phosphonic acid moieties (phosphobetaine groups). There has been an intensive effort over the past decades to prepare and explore potential applications of the synthetic PC-polymers[2].In this paper, we describe a facile synthesis of chitosan derivatives containing zwitterionic secondary/tertiary amine and phosphonic acid groups and their further N-phosphobetainates. The polyelectrolyte effect and anti-polyelectrolyte effect of the chitosan-based zwitterionic polyelectrolytes were studied.     

Research on HJ-1A/B satellite data automatic geometric precision correction design

Developed independently by China, HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data. The realization of the observation data geometric precision correction is of great significance for macro and dynamic ecological environment monitoring. The paper analyzed the parameter characteristics of HJ- 1 satellite and geometric features of HJ- 1 satellite level 2 data （systematic geo-corrected data）. Based on this, the overall H J- 1 multi-sensor geometric correction flow and charge-coupled device （CCD） automatic geometric precision correction method were designed. Actual operating data showed that the method could achieve good result for automatic geometric precision correction of HJ- 1 sat- ellite data, automatic HJ- 1 CCD image geometric precision correction accuracy could be achieved within two pixels and automatic matching accuracy between the images of same satellite could be obtained less than one pixel.     

基于H.264Intra帧的错误掩藏算法

H.264/AVC中Intra帧的传输错误会在空间和时间上扩散,导致图像质量的急剧恶化,本文提出了一种基于图像纹理走向的Intra帧错误掩藏方法,以Sobel梯度算子计算受损宏块周边正确接收宏块像素的梯度,对丢失宏块周围像素进行统计分析,以确定受损宏块的纹理走向,最后利用方向性插值算法重建丢失块.试验结果表明,这种方法与H.264参考软件JM86中方法相比,具有较好的误码掩藏效果.     

基于Masreliez-Martin的鲁棒分数阶容积卡尔曼滤波算法及应用

针对具有非高斯量测噪声的分数阶离散时间非线性系统的状态估计问题, 提出一种基于Masreliez-Martin(简称为M-M)方法的鲁棒分数阶容积卡尔曼滤波器。在分数阶离散非线性动态系统基础上, 使用三阶容积原则推导了状态预测公式, 并使用M-M方法实现状态的量测更新, 构成了基于M-M方法的鲁棒分数阶容积卡尔曼跟踪算法。将提出的算法应用到再入目标的状态估计中, 仿真结果表明, 基于M-M方法的鲁棒分数阶容积卡尔曼滤波器优于分数阶无迹滤波器和分数阶容积卡尔曼滤波器。最后, 分析了不同程度的量测污染噪声对鲁棒分数阶容积卡尔曼滤波算法的估计性能影响, 验证了所提算法的鲁棒性。     

Online support vector regression for reinforcement learning

The goal in reinforcement learning is to learn the value of state-action pair in order to maximize the total reward. For continuous states and actions in the real world, the representation of value functions is critical. Furthermore, the samples in value functions are sequentially obtained. Therefore, an online sup-port vector regression （OSVR） is set up, which is a function approximator to estimate value functions in reinforcement learning. OSVR updates the regression function by analyzing the possible variation of sup-port vector sets after new samples are inserted to the training set. To evaluate the OSVR learning ability, it is applied to the mountain-car task. The simulation results indicate that the OSVR has a preferable con- vergence speed and can solve continuous problems that are infeasible using lookup table.     

（W／O）／W液膜体系中混和表面活性物质在界面的吸附特性

在Ｇｉｂｂｓ－Ｄｕｈｅｍ方程的基础上，推导出了计算（Ｗ／Ｏ）／Ｗ乳化液膜体系表面活性物质界面组成的公式．通过实验测定其睦相对外相界面张力与反相中表面活性物质总浓度及载体浓度之间的变化关系，研究了表面活性剂及载体在界面上的不同吸附行为．并对各种变化关系进行了理论分析．探讨了乳化液膜界面上表面活性物质组成的变化关系与液膜稳定性及传质过程之间的联系，为进一步研究乳化液膜的真实分离过程提供了一定的理论基础．     

ZnCrO4系多功能陶瓷的研制

探讨了ＺｒＪＣｒＯ＿４系多功能陶瓷的制备工艺及其功能．此类陶瓷，除具有湿敏特性外，还具有ＮＴＣ热敏及压敏功能，是一类有应用前景的功能陶瓷。     

基于小波和非线性含输入自回归模型的系统辨识算法

提出了一种结合小波理论和非线性含输入自回归(NARX)模型的系统辨识新算法．该算法利用小波函数有效的逼近能力避免了应用NARX模型系统辨识时确定模型结构的复杂过程，消除了通常小波网络辨识算法由于输入变量之间可能存在巨大差别而引入的严重失真，构成了一个通用、有效、不依赖于系统先验信息的非线性辨识框架．两则数据仿真表明，对于高度非线性系统，该算法可使系统估计的均方误差减少60％以上．     

二硫化碳接触者职业危害特点分析

目的探讨二硫化碳接触者职业危害特点.方法回顾性队列调查.结果随着接触时间的增加,二硫化碳接触者的职业危害发生率增加.作业工人的自觉症状与体征的发生率在5及10 a工龄组间上升幅度最快,实验室检查心电、脑电、血脂的异常率在20 a及以上组较为明显.结论二硫化碳对作业工人的职业危害随接触时间的增加而加重.     

钛酸钡锶复盐超微陶瓷粉末制备以及粉末结构测定

本文首次报道采用简单低耗的有机介质化学共沉淀法,制备超微陶瓷粉末钛酸钡锶复盐(Ba_xSr(1-x)TiO_3)。由扫描电镜观测其平均粒径在0.45μm以下。由X-粉晶衍射图得到,该复盐粉末属于BaTiO_3(四方)与SrTiO3(立方)的混晶。