靶向淋巴系统造影剂的制备及其动物实验

采用两种方法,一种方法是以右旋糖酐（Dextran）和DTPA的二酐为原料,DMAP为催化剂,另一种是以右旋糖酐和DTPA为原料,采用DMAP及EDC.HCl为联合催化剂,合成造影剂Dextran-DTPA-Gd.通过比较产物的水溶性及Gd含量确定了最佳制备条件,得到了钆含量为16.1%、水溶性好的高分子造影剂;通过FTIR、粒度分析表征了Dextran-DTPA-Gd的结构及其分子粒径大小（分布范围为100～150nm,平均值为130nm）;动物实验中,以钆喷酸葡胺注射液（Magnevist）为阳性对照,通过对比家兔腿部磁共振成像图,绘制腿部淋巴系统信号增强率-时间曲线,证明Dextran-DTPA-Gd具有更高的信号增强效果（最高值为314%）及淋巴系统选择性的特点,为其进一步应用奠定了基础.     

一个水稻苗期黄化叶突变体基因的定位

通过筛选甲基磺酸乙酯(Ethyl Methane Sulfonate,EMS)诱变的籼稻Kasalath突变体库,得到一个黄化叶突变体Osyl1(Oryza sativa yellow leaf 1),在二叶期前该突变体叶色黄化,后期突变体叶色逐渐恢复到野生型水平.遗传分析显示Osyl1突变性状受一对隐性基因控制,经图位克隆技术将Os YL1基因定位在水稻第3染色体上的STS(Sequence Tagged Site)标记S5362和S5845之间,物理距离约为483 kb,在该区间内无已知黄化叶相关基因.对Os YL1基因的定位,为该基因的克隆打下基础.     

微通道蛋白质吸附的流动电势表征

蛋白质在固体表面的吸附与许多生命现象和生物应用相关,比如血液凝结、细胞粘附及材料的生物相容性等~([1]),也是化学、生物、医学、材料等多种学科都密切关注的问题~([2]),相应研究有很大的科学价值和应用前景.     

基于β-二酮类铕(Ⅲ)配合物的一氧化氮荧光探针的设计、合成及应用研究

以含一氧化氮(NO)识别基团邻二氨基苯基的联三吡啶衍生物4-(4-[2,2′:6′,2″]三联吡啶-4′-基-苯氧基)-苯-1,2-二胺(TPBD)为配位体,β-二酮类化合物5-(1′,1″-二苯基-4′-基)-1,1,1,2,2,3,3-七氟-4,6-己二酮(DHH)为共配体,设计并合成了一种用于检测NO的β-二酮类铕Ⅲ配合物荧光探针[Eu(DHH)₃(TPBD)],采用质谱和元素分析确证其结构。光谱研究结果表明,探针[Eu(DHH)₃(TPBD)]本身仅发出微弱的光,与NO反应后荧光强度增强近10倍,定量检测NO的线性浓度范围为0.017～0.83μmol/L,检出限为7.4 nmol/L。探针[Eu(DHH)₃(TPBD)]对几种常见的活性氧/氮物种基本上不响应,对NO显示出良好的选择性。荧光成像实验表明,探针[Eu(DHH)₃(TPBD)]具有低细胞毒性和线粒体靶向定位性能,并成功实现对RAW 264.7活细胞和斑马鱼体内的NO的时间分辨荧光成像检测。     

层流对流换热中的势容耗散极值与最小熵产

在一定的约束条件下,存在一个最优的速度场,它能够使得温度场和速度场的协同程度最好,从而使得对流换热的整体传热性能达到最优。目前对传热效果的评价存在熵产最小化和势容耗散取得极值两种不同的准测。分别根据这两种优化准则,用变分方法推导了在粘性耗散一定的条件下,稳态无内热源的层流对流换热的场协同方程,并对方腔内对流换热问题进行了优化。数值计算结果表明,势容耗散取得极值时的换热效果优于熵产最小的结果,因此势容耗散极值原理更适合做为对流换热的优化准则。     

First-principles study on with nitrogen and anatase TiO2 codoped praseodymium

<正>The crystal structures,electronic structures and optical properties of nitrogen or/and praseodymium doped anatase TiO₂ were calculated by first principles with the plane-wave ultrasoft pseudopotential method based on density functional theory.Highly efficient visible-light-induced nitrogen or/and praseodymium doped anatase TiO₂ nanocrystal photocatalyst were synthesized by a microwave chemical method.The calculated results show that the photocatalytic activity of TiO₂ can be enhanced by N doping or Pr doping,and can be further enhanced by N+Pr codoping.The band gap change of the codoping TiO₂ is more obvious than that of the single ion doping,which results in the red shift of the optical absorption edges.The results are of great significance for the understanding and further development of visible-light response high activity modified TiO₂ photocatalyst.The photocatalytic activity of the samples for methyl blue degradation was investigated under the irradiation of fluorescent light.The experimental results show that the codoping TiO₂ photocatalytic activity is obviously higher than that of the single ion doping.The experimental results accord with the calculated results.     

废气铅的测定中玻璃纤维滤筒的消解方法

<正>近些年,随着我国经济的飞速发展,大气环境污染日趋严重,雾霾及其所含的重金属直接威胁着人们的身体健康。铅是日常生活中常见的重金属元素,长期接触铅及其盐类化合物,可以导致肾病,尤其破坏儿童的神经系统[1]。在对大气污染源的日常监测中,铅尘是比较常规的监测项目。在国内,固定污染源废气铅尘的采样多以玻璃(或石英)纤维滤筒为主,这主要是因为玻璃纤维滤筒结构简单,使用方便又有较高的捕集效率[2]。但     

基于Fourier变换的快速高分辨波前重构方法北大核心CSCD

为实现快速高分辨的哈特曼波前测量,研究了基于Fourier变换的波前重构方法。在软件设计和代码实施基础上进行了时间性能统计分析,采用模拟数据和实际斜率数据进行波前重构,并将重构结果与VMM方法获得的结果进行了比较,分析其误差产生的原因及噪声的统计特性与误差空间分布的关系。仿真和实验结果表明,FTR方法具有从斜率数据准确重构出波前的能力;相对VMM方法FTR拥有更优的时间性能;基于相同的斜率FTR方法重构出波前与VMM方法的差别主要分布在孔径的边缘,在附加在斜率测量上的噪声具有零平均的性质时,最有可能获得一致的波前。     

First-principles study on anatase TiO2 codoped with nitrogen and praseodymium

The crystal structures, electronic structures and optical properties of nitrogen or/and praseodymium doped anatase TiO₂ were calculated by first principles with the plane-wave ultrasoft pseudopotential method based on density functional theory. Highly efficient visible-light-induced nitrogen or/and praseodymium doped anatase TiO₂ nanocrystal photocatalyst were synthesized by a microwave chemical method. The calculated results show that the photocatalytic activity of TiO₂ can be enhanced by N doping or Pr doping, and can be further enhanced by N+Pr codoping. The band gap change of the codoping TiO₂ is more obvious than that of the single ion doping, which results in the red shift of the optical absorption edges. The results are of great significance for the understanding and further development of visible-light response high activity modified TiO₂ photocatalyst. The photocatalytic activity of the samples for methyl blue degradation was investigated under the irradiation of fluorescent light. The experimental results show that the codoping TiO₂ photocatalytic activity is obviously higher than that of the single ion doping. The experimental results accord with the calculated results.     

ITER第一壁铍铜连接部件在高热负荷作用下的热性能分析

对ITER屏蔽包层第一壁板铍铜连接件在高热负荷作用下的传热性能进行了分析,模拟了第一壁铍铜连接手指部件的热应力和热应变,得到其对应的热疲劳寿命.计算结果表明,在局部4.7MW?m-2高热负荷作用和ITER水冷条件下,现有设计方案中的铍铜连接件的热性能和热疲劳性能均满足设计要求.