Triton X-100敏化鱼精蛋白共振能量转移荧光猝灭法测定尿中8-羟基脱氧鸟苷

研究了8-羟基脱氧鸟苷与鱼精蛋白之间的共振能量转移的最佳条件,建立了鱼精蛋白共振能量转移荧光猝灭法测定8-羟基脱氧鸟苷的新方法.在301 nm,pH 8.2的Tris-HCl缓冲溶液中,鱼精蛋白的荧光猝灭强度与8-羟基脱氧鸟苷的浓度成正比,工作曲线的线性范围为0.50～7.1 μg·mL-1,r=0.996 7,方法的检出限为0.18 μg·mL-1,RSD=6.2%,平均加标回收率为104%(n=6).     

七个倍半萜2-亚甲基-r-内酯的同二色散的研究

Using sesquiterpene lactone rule, the absolute configurations of seven sesquiterpene α-methylene-γ-lactones were confirmed. Compounds 1, 2, 3, 4 and 6, 7 are cis-fused γ-lactones, and compound 5 is trans-fused γ-lactone.     

ρ*混合相依变量的完全收敛性

设{Yi;-∞＜I＜∞}是同分布的ρ*混合随机变量序列,{ai;-∞＜I＜∞}是绝对可加的实数序列,{Xnk;1≤k≤n,n≥1}是行内随机变量为ρ*混合的随机变量组列,令Cnk=EXnkI{|Xnk|≤n1/p}.在适当的条件下建立了{n∑k=1∞∑I=-∞ai+kYi/nα;n≥1}和{n∑k=1(Xnk-Cnk)/n1/p;n≥1)}的完全收敛性.     

NEWTON–GMRES ALGORITHM APPLIED TO COMPRESSIBLE FLOWS

This paper addresses the resolution of non-linear problems arising from an implicit time discretization in CFD problems. We study the convergence of the Newton–GMRES algorithm with a Jacobian approximated by a finite difference scheme and with restarting in GMRES. In our numerical experiments we observe, as predicted by the theory, the impact of the matrix-free approximations. A second-order scheme clearly improves the convergence in the Newton process.     

电介质球复合纳米天线对荧光定向发射的增强

在纳米光子学中,提高荧光物质的定向发光强度是许多应用要解决的关键问题。为了优化电介质纳米天线的荧光增强能力,本文提出了一种由硅纳米球二聚体与TiO 2微球组成的电介质球复合纳米天线。通过时域有限差分法,本文分别从量子产率增强、荧光收集效率增强以及荧光激发率增强3个方面研究了该复合纳米天线对荧光的增强效果。结果表明,这种复合纳米天线不仅可以解决单个TiO 2微球增强荧光时量子产率较低的问题,还可以弥补单个硅纳米球二聚体增强荧光时荧光收集效率较差的不足。该复合纳米天线可使CdSe量子点的量子产率增强约4倍、荧光收集效率增强约2倍。此外,由于硅纳米球二聚体与TiO 2微球对荧光激发过程具有增强效果,该复合天线最终可以产生较高的荧光定向增强倍数。在量子点发光的中心波长523 nm处,荧光定向增强约为3064倍。     

羟自由基(OH)、超氧阴离子(O2-)与线粒体低水平化学发光相关性的研究

以线粒体为模式体系,研究了低水平化学发光的过程和机制。实验发现在一定浓度范围(蛋白0-100毫克/毫升)内,线粒体悬液的发光是随浓度的升高而增强。最适宜的测量条件为35℃和pH=7.A.注入外源性^·OH和^·OH的清除剂证实,OH可起动脂质过氧化反应,且¹O₂是构成发光的体内光子源。超氧化物歧化酶(SOD)对线粒体发光有调节作用。     

Two Alkali Metal Germanophosphates Na3[Ge(OH)(PO4)2]·2H2O and Li2Na[GeO(HPO4)(PO4)]:Crystal Structures and Thermal Stability

Two new alkali metal germanophosphates,namely,Na₃[Ge(OH)(PO₄)₂]·2 H2 O and Li₂Na[GeO(HPO₄)(PO₄)],have been prepared by solvothermal method,and their crystal structures were determined by single-crystal X-ray diffraction.The title two compounds crystalize in the same orthorhombic space group Pbcm(No.57)and feature similar chain-like structure which is built from zig-zag GeO₆ octahedral thread loop branched by PO₄ tetrahedra.For Na₃[Ge(OH)(PO₄)₂]·2 H₂O,a=10.1650(9),b=13.1975(12),c=6.9751(7)?,V=935.73(15)?³,Z=4,R=0.0356 and wR=0.1109;and for Li₂Na[GeO(HPO₄)(PO₄)],a=6.9855(5),b=14.5809(18),c=6.6620(5)?,V=678.56(11)?³,Z=4,R=0.0286,and w R=0.0762.The partial substitution of Na ions by Li ions not only significantly influences the total structural features and the water molecule contents,but also impacts on their thermal stabilities.Li₂Na[GeO(HPO₄)(PO₄)]is thermally stable up to 400℃,whereas only 150℃ for Na₃[Ge(OH)(PO₄)₂]·2 H2 O.     

一种基于清晰度计算的NSCT域多聚焦图像融合算法

针对多聚焦图像的特点．提出了一种基于清晰度计算的非抽样轮廓波变换（Non-Subsampied Contourlet’Transform,NSCT）域多聚焦图像融合算法。该算法首先对源图像进行NSCT分解．以此克服传统Contourlet变换不具平移不变性的缺点。在分析光学成像中散焦表现形式的基础上．对分解后的低频子带和高频方向子带分别以“邻域梯度”及“合成邻域模值”作为清晰度指标。采用自适应选择法实现对多聚焦图像的融合处理。实验结果表明,该方法不仅能有效融合图像中的“伪影”和“振铃效应”．视觉效果明显优于传统小波和Contourlet方法,且融合图像的熵、交叉熵及均方根交叉熵等客观评价指标也有明显提高。     

基于激光技术的压痕应变花及测试应变的原理

介绍了一种用于测试面内三个应变分量的应变测量技术,在试件表面预先压制三个压痕,通过激光照射压痕,经衍射后干涉,产生干涉图。通过分析变形前后干涉斑点的光强值的变化来对待测位置进行应变测量。实验表明该方法对待测试件表面损伤小,且压痕应变花尺寸小,是一种新的光学应变测试技术,不仅可以用来进行普通应变测量,尤其对解决小空间应变测试问题有其独特的优点。     

Polymer Supported Synthesis of Multi-substituted Pyrimidine-4-one Derivatives via Pb f-activated Thiourea

Efficient polymer supported synthesis of multi-substituted pyrimidine-4-one derivatives was described. Target products were produced from fluorenylmethoxycarbonyl(Fmoc) protected β-amino acid loaded on hydro- xymethyl resin through deprotection, N-alkylation, guanidine formation, and cleavage of 2,2,4,6,7-pentamethyl dihy-drobenzofuran-sulfonyl(Pbf) by trifluoracetic acid(TFA) followed with cyclization. The procedure has the advantages of easy operation, mild reaction conditions, and forming multiple substi...