准直准单能靶面电子加速实验研究

实验上使用大能量、亚ps激光脉冲大角度入射固体靶,获得了沿靶面方向定向传播、发散角仅有2°、峰值能量为3–4 Me V的准直、准单能电子束.实验发现激光对比度对靶面电子束的产生起到了至关重要的作用,最佳的对比度为5×10-6.在此最优化条件下,通过背向散射光谱分析发现,共振吸收激发的等离子体波加速可能是电子的主要加速机制.探针光阴影成像及等离子体自发光的精细结构显示,预脉冲与固体靶相互作用中产生了尺度100μm左右的过临界密度预等离子体.这种等离子体的作用类似于等离子体反射镜,使得激光脉冲被限制在预等离子体区与靶面之间,因而最终造成了电子束沿靶面方向的导引.这种靶面电子束因其合适的能量范围、高度的准直性及沿靶面方向定向传播的特性有望在惯性约束聚变尤其是锥靶快点火中得到应用.     

端羟基超支化聚酯的改性及性能研究

以三羟甲基丙烷和二羟甲基丙酸为原料,在对甲苯磺酸催化下合成了端羟基超支化聚酯,8-[4′-丙氧基（1,1-联苯）-氧]-辛酸为封端剂对超支化聚酯进行改性,采用羟值滴定确定封端率。通过红外光谱（FT-IR）和核磁共振谱(NMR)对改性前后超支化聚酯的化学结构进行了表征,并采用差示扫描量热法（DSC）和广角X射线衍射（WAXD）对所合成超支化聚合物的热性能进行了研究。结果表明,封端剂的最佳用量为聚合物中羟基物质的量的1.05倍,在此条件下,超支化聚合物封端率达到92.02%;改性前后聚合物化学结构与理论结构一致,改性后聚合物玻璃化温度显著升高,且聚合物物相由无定形态转变为晶态与非晶态共存。     

跳汰机床层松散状况递归神经网络内模控制

该文提出一种基于对角递归神经网络的内模控制系统 ,并以跳汰生产过程床层松散状况为对象进行了研究。仿真结果表明 ,该系统具有很好的动态响应 ,而且对外部扰动和模型误差具有良好的鲁棒性     

基于单形体几何的高光谱遥感图像解混算法

提出一种新的基于单形体几何的高光谱遥感图像混合像元丰度估计算法.该算法的目标是在已知端元矩阵的基础之上,估计高光谱图像中各个观测像素点中每个端元的丰度.根据凸几何理论,基于线性混合模型的高光谱解混问题可以看成一个凸几何问题,其中端元位于包含整个高光谱数据集的单形体的顶点,而它们对应的重心坐标则可以看作各个观测像素的丰度.提出的方法由3部分组成,分别为基于单形体体积的重心坐标计算方法、距离几何约束问题和基于内点的单形体子空间定位算法.与其他基于单形体几何的算法相比,该方法具有诸多优点.Cayley-Menger矩阵的引入使得欧式空间上的运算转化为距离空间上的运算,在降低运算复杂度的同时很好地兼顾到数据集的几何结构.而且,单形体重心的使用确立了一种快速而精确的判断方法来确定观测像素所属的子空间,进而利用递归的思想得到丰度值.此外,算法核心仅仅涉及观测点与端元之间的距离,而与波段数无关.因此,该算法无须对数据执行降维处理,从而可以避免因数据降维而造成的有用信息的丢失.仿真和实际高光谱数据的实验结果表明,所提出的算法与同类其他优秀的算法如FCLS和SPU相比,具有更高的运算精度,同时在端元数目较小时具有较快的运算速度.     

Self-assembly and drug delivery behaviors of a novel thermo-sensitive block glycopolymer

A novel thermo-sensitive block glycopolymer based on peracetylated maltoheptaose (AcMH) and poly(2-ethyl-2-oxazoline) (PEtOz) was synthesized for the first time and characterized by hydrogen nuclear magnetic resonance (¹H NMR) spectroscopy and gel permeation chromatograph (GPC) analyses. To obtain such a block polymer, the dihydroxyl poly(2-ethyl-2-oxazoline) homopolymer (OH-PEtOz-OH) was first synthesized by cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EtOz), and then coupled with the peracetylated maltoheptaose having a free hydroxyl group at the reducing end (AcMH-OH) prepared from β-cyclodextrin. It was found that the obtained block polymer could self-assemble into nanosize spherical micelles with a distinct core-shell structure in aqueous solution triggered by its amphiphilic character without any organic solvent. The model drug indomethacin (IND) was efficiently loaded into the resultant polymeric micelles, which was confirmed by ¹H NMR spectra, transmission electron microscope (TEM) and dynamic light scattering (DLS) techniques. The release behavior of IND loaded micelles was well in response to the environmental temperature change. It is suggested that the resulting micelles might be a potential targeted carrier for drug delivery.     

Hotspots of the sensitivity of the land surface hydrological cycle to climate change

Due to the shortage of the global observational data of the terrestrial hydrological variables,the understanding of how surface hydrological processes respond to climate change is still limited.In this study,the Community Land Model(CLM4.0)with high resolution atmospheric forcing data is selected to simulate the global surface hydrological quantities during the period 1948–2006and to investigate the spatial features of these quantities in response to climate change at the regional scales.The sensitivities of evaporation and runoff with respect to the dominant climate change factors(e.g.temperature and precipitation)derived from the concept of climate elasticity are introduced.Results show that evaporation has a declining trend with a rate of 0.7 mm per decade,while runoff shows a weak increasing trend of 0.15 mm per decade over the global land surface.Analyses of the hotspots in the hydrological cycle indicate that the spatial distributions for evaporation and runoff are similar over many areas in central Asia,Australia,and southern South America,but differ largely in high latitudes.It is also found that,the evaporation hotspots in arid regions are mainly associated with the changes in precipitation.Our sensitive analysis suggests that the hydrological quantities show a rather complicated spatial dependency of response of the water cycle to the different climate factors(temperature and precipitation).     

培养和激发学习动机提高对病理学的学习兴趣

病理学是一门重要的医学基础课，理论性强，讲起来较抽象，如果学生对学习的积极性不高，就会影响到学习效果；而通过对学生学习动机的培养和激发．使学生有明确的学习动机，加上老师的正确的引导和教学方法的不断改进以及教学内容的不断更新，可以提高学生的学习兴趣．加强对病理知识的掌握。     

基于MVC模式的Java Web应用设计

简要介绍了MVC的设计模式,讨论了JSP,Servlet和JavaBean技术的概念,同时对基于MVC设计模式如何利用Java的多种技术开发Web应用进行了研究。最后给出一个Web应用系统身份认证的设计和开发的实例。     

Cytotoxicity and genotoxicity of multi-walled carbon nanotubes with human ocular cells

Cytotoxicity and genotoxicity of plasma-modified multi-walled carbon nanotubes (MWCNTs), including hydroxyl-MWCNTs (MWCNT-OH), carboxyl-MWCNTs (MWCNT-COOH) and pristine MWCNTs, with human ocular cells (e.g. retinal pigment epithelium (RPE) cells) have been studied in this work. The addition of MWCNT-based materials caused few change in cell morphology while the presence of MWCNTs was observed inside the cells using transmission electron microscopy (TEM), suggesting possibility of MWCNTs passing through the cell membranes without damaging cells. Cell viability measurements suggested that MWCNT-COOH exhibited better biocompatibility than other MWCNT materials studied in this work. Lactate Dehydrogenase (LDH) release level was found to be less than 30% with all types of MWCNT-based materials. Reactive Oxygen Species (ROS) generation was visible but not severe with addition of nanotubes. A smaller oxidative stress level was obtained from MWCNT-COOH. Cell apoptosis was found to be less than 1.5% with addition of MWCNT-based materials. Particularly MWCNTs were found to be swallowed by cells and released by cells after 72 h without damaging cells, which may be considered as a potential vector for ocular genetic diseases. Plasma modification of MWCNTs particularly with-COOH was found to be an efficient way to improve ocular biocompatibility of MWCNTs, suggesting a fast and useful way to modify MWCNTs for applications in areas such as biology and biomedicine.     

2,2,6,6-四羟甲基环己醇五烯丙基醚的合成

以环己酮、甲醛为原料在碱催化下经羟醛缩合,康尼扎罗两步反应制得中间体2,2,6,6-四羟甲基环己醇。此化合物在季铵盐相转移催化下与氯丙烯反应生成2,2,6,6-四羟甲基环己醇五烯丙基醚。用红外光谱、¹³C和¹H核磁共振谱对2,2,6,6-四羟甲基环己醇和2,2,6,6-四羟甲基环己醇五烯丙基醚进行了表征。探讨了反应温度,催化剂用量,物料物质的量比等对2,2,6,6-四羟甲基环己醇和2,2,6,6-四羟甲基环己醇五烯丙基醚产率的影响。结果表明,合成2,2,6,6-四羟甲基环己醇的适宜条件为：n（碱）∶n（甲醛）∶n（环己酮）＝1.25∶5.5∶1,羟醛缩合反应温度和反应时间分别为10℃和1h,康尼扎罗反应温度和时间分别为40℃和1.5h;合成2,2,6,6-四羟甲基环己醇五烯丙基醚的适宜条件为：n（氢氧化钠）∶n（氯丙烯）∶n（2,2,6,6-四羟甲基环己醇）=9∶10∶1,相转移剂用量为10%（以2,2,6,6-四羟甲基环己醇质量为基准）,反应温度和时间分别为80℃和120h,2,2,6,6-四羟甲基环己醇五烯丙基醚产率为58.3%。