Photoluminescence of Er-doped hydrogenated amorphous silicon nitride

Er photoluminescence (Er PL) and dangling bonds (DBs) of annealed Er-doped hydrogenated amorphous silicon nitride (a-SiN:H(Er)) with various concentrations of nitrogen are studied in the temperature range 62-300 K. Post-annealing process is employed to change the DBs density of a-SiN:H(Er). PL spectra, DBs density and H, N concentrations are measured. The intensity of Er PL displays complicated relation with Si DBs density within the annealing temperature range 200-500 degreesC. The intensity of Er PL first increases with decreasing density of Si dangling bonds owing to the structural relaxation up to 250 degreesC, and continues to increase up to 350 degreesC even though the density of Si DBs increases due to the improvement of symmetry environment of Er3+. (C) 2003 Elsevier B.V. All rights reserved.

STRUCTURE AND SITE-SYMMETRY INVESTIGATION ON THE HEXAGONAL KCAY(PO4)(2)

A new double phosphate, KCaY(PO4)(2), isostructural with hexagonal LaPO4, is reported. It crystallizes in the hexagonal system with a = 0.6903 nm and c = 0.6331 nm. Its vibrational spectra, IR and Raman spectra showed that the site symmetry of the PO4 anion slightly deviated from D-2 toward C-2.

Studies on interaction of bovine serum albumin with indo-1 by fluorescence spectroscopic method

The binding-site number was calculated by using fluorescence spectroscopic method with bovine serum albumin(BSA) and Indo-1 as protein and ligand models, respectively. The method for calculating binding-site number in BSA for Indo-1 was developed based on the relationships between the changes of Indo-1 fluorescence intensity and the analytical concentration of BSA. And the interaction of BSA with Indo-1 was investigated comprehensively by using fluorescence techniques as well as fluorescence resonance energy transfer, and the thermodynamic parameters were calculated according to the changes of enthalpy on temperature.,

聚碳酸1,2-丙二酯/聚琥珀酸丁二酯/邻苯二甲酸二烯丙酯共混体系的研究

采用熔融共混的方法制备了聚碳酸1,2-丙二酯(PPC)/聚琥珀酸丁二酯(PBS)共混物和PPC/PBS/DAOP(邻苯二甲酸二烯丙酯)增塑共混物,对共混物的相容性、热性能、结晶性和物理机械性能进行了初步研究.研究结果表明PPC/PBS共混物为不相容体系,PPC对PBS的结晶度影响很小;PBS的加入提高了共混物的起始热分解温度(Td-5%),当共混物中PBS含量从10%增加到90%时,共混物的Td-5%可分别增加15℃到59℃.DAOP对PPC/PBS共混物有增塑作用,当PPC/PBS/DAOP的比例从30/70/0变化到30/70/30时,共混物玻璃化转变温度(Tg)下降了36.9℃.与PPC/PBS共混物相比,组成优化的DAOP增塑共混物PPC/PBS/DAOP(PPC/PBS/DAOP=30/70/5)的断裂伸长率和断裂能最大可提高31倍和34倍,分别达到655.1%和3.4 J/...

牛血清白蛋白与Indo-1相互作用的荧光光谱法研究

以牛血清白蛋白(Bovine serum album in,BSA)与荧光探针Indo-1为蛋白质和配体模型,基于Indo-1的荧光强度与BSA的分析浓度间的关系,建立了计算二者相互作用位点数的方法,并利用荧光共振能量转移及各种荧光技术对Indo-1和BSA的相互作用进行了研究.结果表明,Indo-1在BSA中有3个作用位点,这3个作用位点与BSA中的212位色氨酸(Trp 212)间的距离分别为2.93,2.57和2.40 nm;Indo-1通过疏水性作用进入到BSA的3个疏水性空腔.在荧光猝灭实验中,通过M icrolab 500系列进样器和PTI荧光仪的联用实现了荧光强度的自动和实时记录.

重庆城口地区早前寒武系黑色岩系研究：（1）铂族元素成矿潜力评估

重庆城口地区从震旦统到下寒武统发育有丰富的黑色岩系，20世纪末期在该地区黑色岩系中开展了大量的铂族元素（PGE）的找矿工作，但是由于种种原因，关于该地区是否存在PGE矿化异常，还没有得到最终的结论。本次研究在PGE分析方法论证的基础上，进行了大量样品的PGE分析和微量元素分析。主要结论如下：①区域上上震旦统槽区和断块区两套黑色岩系在原始的沉积环境和物源供给上有较大的差异，虽然槽区上震旦统的黑色岩系具有和下寒武统黑色岩系相似但强度较低的V-Cu-Y-Mo—U异常，但基本上不具有明显的PGE-Au-Ag异常。②断块区水井沱组黑色岩系：和平剖面西段新发现的U-V-Mo-PGE异常可能是今后工作的重点，Pt＋Pd最高达248．9×10^-9,局部U-V都达到了工业品位。③槽区巴山组硅质岩：四个剖面都揭示了在硅质岩中广泛存在连续的PGE异常，87个碳质硅质岩平均含Pt＋Pd 57．2×10^-9，有10个样品Pt＋Pd〉100×10^-9，最高达196．5×10^-9；大部分碳质硅质岩都具有不同程度的V-Cu-Y-Mo-Tl-U组合异常，V都达到了独立矿床的品位要求，其中猪草河、燕子河等剖面还存在厚度较大的富矿地段，特别是燕子河剖面，局部还存在REE＋Y的高异常，值得深入研究。④城巴地区下寒武统黑色岩系存在广泛的PGE异常，但没有达到PGE的矿化要求，建议加强该地区的钒矿和铀矿勘探研究，PGE可以综合评价。