光聚合法对聚异丙基丙烯酰胺纳米凝胶粒径及形状的控制

纳米凝胶粒径和形貌的控制一直是纳米凝胶领域的研究热点。本研究利用光聚合的方法，无需其他有机添加剂，合成出5～100nm范围的聚酰胺凝胶。其粒径分布范围可控制在10nm以内。通过SEM对纳米凝胶形貌进行了表征。从结果看，可在纳米尺度上对凝胶的形状进行控制，并合成出树枝状、球状、核壳结构的纳米凝胶。这些结果未在文献中报道过。     

THE SCANNING NUCLEAR MICROPROBE AT SINR

This paper describes the scanning nuclear microprobe facilities established at the Shanghai Institute of Nuclear Research. The Russion quadruplet constructed with four magnetic quadrupolets is used for microbeam formation. The long focus of the lens makes the working distance long enough to accommodate the scanning coils and the detectors for PIXE, RBS, RFS, NRA and SE experiments. A 5 μm focussed beam is scanned continously by a pair of coils. A multiparameter multidetector data system for the nuclear microprobe is based on the idea of Total quantitative scanning analysis (TQSA) suggested by Melbourne University. A digital graphic displayer is a good substitute for an ordinary storage oscilloscope for on- line scanned area monitoring. The new microprobe meets high demands of biologists and geologists on applications.     

POLYMER DIODES MADE OF ION IMPLANTED POLYACETYLENE FILMS

Polyacetylene films were doped with FeCl3 and implanted with 30 k'eV K+ ions. Physical changes to the films were examined by a series of measurements, which include the four-probe test, infrared ray absorption and 2 MeV He+ particle elastic recoil dettection and Rutherford backscattering. The chemical dopants (Fe+++ and Cl-) were redistributed after the implantation and the different species (K+. Fe+++ and Cl-ions) formed p - n junctions at the implantation depths. The implanted films exhibited desirable Ⅰ-Ⅴ characteristics, with current densities as high as 600 mA/cm- at 3V and back - to - forward ratio of current over 300. The polymer diodes kept their behavior for over 60 days. Discussions on the results were given in detail.     

离子注入法掺杂聚乙炔的初步探索

聚乙炔(CH)x是一种简单的共轭有机导电高分子材料。1975年日本白川首先用高浓度的Ti(OBu)_4-AlEt_3体系在-78℃下定向聚合得到了均匀的、具有高结晶度的顺式(CH)x薄膜。1977年白川与美国MacCDiarmid等合作,发现掺杂能改善(CH)x的导电性能。后来又发现掺入不同的杂质可使(CH)x显示n型或P型半导体的特性。聚乙炔薄膜具有物理上准一维金属膜型的一些特殊性质,因而引起物理学家的广泛兴趣。1980年美国Su、Schrieffer和Heeger提出了聚乙炔的孤立子(Soliton)导电模型,并用这种模型成功地阐述了一些实验现象。(CH)x的原料便宜,合成简单,具有广阔的应用前景。人们预期可以把聚乙炔应用于制备太阳能电池、蓄电池及塑料半导体器件等。     

质子激发X射线分析及其应用

本文主要介绍质子激发X射线(PIXE)分析的物理基础和实验方法,提出了薄靶的单标准标定法和厚靶标定的简化公式。最后,介绍了我们将PIXE分析应用于环境、地球化学、生物医学、法学、考古等领域的若干结果。     

真丝绸的低压汞灯光引发接枝共聚研究

本工作用低压汞灯作为光源,以丙烯酸羟丙酯(2-Hydroxypropyl acrylate,HPA)为单体,对真丝绸的紫外光光化学接技改性进行了系统研究,反应体系中无任何引发剂或者光敏剂.用衰减全反射红外光谱(Attenuated total reflectance infrared spectroscopy,ATR-IR)、差示扫描量热法(Differential scanning calo-danetry,DSC)和热重分析(Thermal gravity analysis,TGA)等对光接枝产物进行了表征.探索了光照反应时间、单体浓度、pH值、多官能团单体的存在对接枝率的影响规律.研究表明,此方法可获得较高的接枝率,且低压汞灯具有无污染、设备简便价格低廉、寿命长,易于操作等优点,是一种有效的真丝绸改性方法.     

PEI介导的E1A基因对结肠癌细胞放疗增敏效应的研究

以自行合成的聚乙烯亚胺纳米凝胶(Polyethylenimine,PEI)为载体转染E1A基因,观察E1A基凶对结肠癌细胞体外生长的抑制作用和对电离辐射的增敏效应,并初步探讨其作用机理.经PEI介导将真核细胞高效表达E1A基因的重组质粒psv-E1A导入人结肠癌细胞系SW480,RT-PCR证实其转染,G418筛选出阳...     

THE DAMAGE MEASUREMENT OF ION- IMPLANTED COMPOUND SEMICONDUCTOR GaAs BY PIXE-CHANNELING TECHNIQUE

A combined PIXE-RBS channeling measurement system to examine Ⅲ-Ⅴ compound semiconductors has been established. Preliminary results on studying Si+ and Te+ implanted GaAs have been presented and discussed.     

真丝绸表面光接枝2-(双甲基胺)乙基甲基丙烯酸酯改性研究

真丝绸的染色性能差,是制约真丝绸市场竞争力的主要因素之一。在前人使用化学方法和高能辐射方法对真丝绸接枝共聚改性的研究基础上,本工作在不添加任何光引发剂或光敏剂的前提下,利用紫外光对真丝绸表面进行光化学接枝改性。详细研究了紫外光源类型、单体类型、单体浓度、光照时间、反应环境温度、表面活性剂、pH值等诸多因素对接枝率和相应接枝共聚物的物理化学性质的影响,探索接枝条件对接枝共聚物微观结构和性能的影响规律,并着重研究接枝单体、接枝条件与真丝绸染色性能的对应关系。     

高剂量辐照猪肉的挥发物、脂氧化和感官特征分析

经蛋白酶钝化与真空包装的猪里脊肉样品在-20℃作最高剂量达45kGy的^60Coγ射线辐照。观察或测定了辐照猪肉的感官特征变化、挥发物产生和脂氧化。实验结果表明,辐照味与脂氧化无关,而蛋白质辐解产物可能是辐照味的来源。志愿者品尝结果表明,辐照猪肉并无不易接受的感官特征变化。