PbS纳米晶制备中不同溶剂对其微观形貌的影响

近年来,纳米材料在石油化工和化工催化领域得到非常广泛的应用.利用水热/溶剂热法,通过在室温下水溶液中醋酸铅和二乙基二硫代氨基甲酸钠的沉淀反应,合成出了单分子前驱体Pb-DDTC;然后,在没有使用任何表面活性剂或模板的情况下,分别在以水、无水乙醇、乙二醇和乙二胺作为反应介质的不同溶剂中,很好地合成出了粒径为50～100 nm的PbS纳米晶.并利用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等多种测试手段对所得纳米晶体进行了表征,证实了所得晶体均为PbS纳米级纯相晶体,且溶剂的选择对产品的形貌具有一定的影响.     

PbS纳米微粒对溴化银微晶乳剂的化学增感作用

发现了PbS纳米微粒对溴化银乳剂的化学增感作用，对PbS和Na2S2O3对卤化银乳剂的增感作用进行了比较，研究了增感剂用量、增感温度和pAg值、溴化银的晶型等因素的影响，以及PbS纳米微粒与HAuCl4的协同增感效应。     

Detection of melamine based on the fluorescence resonance energy transfer between CdTe QDs and Rhodamine B

In this paper, we constructed the fluorescence resonance energy transfer (FRET) system between MPA-capped CdTe quantum dots (QDs) and Rhodamine B (RB) in the environment of cetyltrimethylammonium bromide (CTAB). In this system, CdTe QDs were treated as energy donors, whilst RB was treated as energy acceptor. CTAB was used to make the distance between the particles of CdTe QDs and RB closer to improve the efficiency of FRET system. We optimized some important factors which would affect the efficiency of FRET system. Under the optimized experimental conditions, melamine (MB) could be detected based on the fluorescence intensity changes of RB in the FRET system. We could get a linear relationship between the fluorescence intensity of RB and the concentration of MB in the range of 0.05–4.0 μmol/L and the detection limit was 0.01 μmol/L. The proposed method was applied for the determination of melamine in milk samples with satisfactory results.     

量子点探针测定痕量金属离子

量子点是近几年发展起来的新型纳米材料。因其独特而优良的荧光特性,量子点成为了一种具有很大发展潜力的荧光探针。将量子点作为标记物的荧光分析法也成为国内外研究学者的研究热点。这种新型荧光分析法已经广泛地应用于生物科学、医学、分析化学等领域,并显示出极大的优越性。本文集中叙述了修饰剂对量子点的荧光性质的影响和量子点在分析检测痕量金属离子方面的应用,讨论了金属离子与量子点作用后荧光猝灭或荧光增强的可能的机理。     

Theoretical study of the interaction between PbS and triethanolamine as its complexing agent

We performed a theoretical analysis of the systems formed by Pb/PbS with one or two molecule(s) of triethanolamine as a complexing agent. Conformational analysis, geometry optimizations and frequency calculations at the MP2/LANL2DZ level of theory were performed to check the isomer stabilities.     

高灵敏度、小视场角炮口焰红外触发器的研究

传统红外辐射探测装置的调理电路由场效应管和高阻抗运放组成,探测灵敏度较低、输出不稳定且场效应管极易损坏,对红外辐射探测装置的可靠性带来负面影响,从而影响到弹药、武器系统的正常测试。本文采用运算放大器作为调理电路,使用带有瞄准具的小视场光学系统并整体设计红外辐射探测装置。采用差分信号输出,提高长距离传输脉冲信号能力,方便后续处理及直观观察,同时也有效提高了探测装置的灵敏度,抗干扰能力强、轻巧、适用于各种环境。     

Enhanced photovoltaic property by forming p-i-n structures containing Si quantum dots/SiC multilayers

Si quantum dots (Si QDs)/SiC multilayers were fabricated by annealing hydrogenated amorphous Si/SiC multilayers prepared in a plasma-enhanced chemical vapor deposition system. The thickness of amorphous Si layer was designed to be 4 nm, and the thickness of amorphous SiC layer was kept at 2 nm. Transmission electron microscopy observation revealed the formation of Si QDs after 900°C annealing. The optical properties of the Si QDs/SiC multilayers were studied, and the optical band gap deduced from the optical absorption coefficient result is 1.48 eV. Moreover, the p-i-n structure with n-a-Si/i-(Si QDs/SiC multilayers)/p-Si was fabricated, and the carrier transportation mechanism was investigated. The p-i-n structure was used in a solar cell device. The cell had the open circuit voltage of 532 mV and the power conversion efficiency (PCE) of 6.28%.

PACS

81.07.Ta; 78.67.Pt; 88.40.jj     

扫描近场光学显微镜对细胞超微结构的研究

扫描近场光学显微镜(SNOM)突破了光学显微镜的衍射极限,在细胞研究中具有高灵敏性、无侵入性等优点,已经广泛的应用于生物学研究中。本文综述了SNOM在细胞膜、细胞器、细胞精细结构和单分子探测等领域的研究进展,介绍了扫描近场光学显微镜结合量子点的方法,并对其应用前景做了展望,对其面临困难做了概述。作为一种研究工具,SNOM在生物领域的应用还远远不足。