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991.
含纳米棒银溶胶的制备及其光谱性质研究 总被引:1,自引:0,他引:1
以CTAB表面活性剂胶束为模板用化学还原法制备出含有银纳米棒的银胶体,用透射电镜(TEM)对颗 粒形貌进行了表征.UV Vis吸收谱显示,含银纳米棒溶胶有两个吸收蜂,其中长波长吸收峰位置随胶粒长径比增 加迅速红移和宽化.用多尺寸统计平均的Mie散射模型计算了纳米棒银胶体的吸收谱,较好地解释了长波长吸收 峰的宽化.以此胶体为衬底材料,测量了染料分子的表面增强拉曼散射(SERS),结果显示,SERS强度随胶体中 所含纳米棒长径比的增加呈现先显著增强后缓慢减弱的变化规律,用电磁增强理论对有关现象进行了分析. 相似文献
992.
Xiaoming Wu Yulin Hua Zhaoqi Wang Jiajin Zheng Shougen Yin Jiachun Deng Kongwu Wu Songliu Feijian Zhu Xia Niu 《Optik》2006,117(8):373-376
A bright white organic light-emitting diode (OLED) has been successfully fabricated in which a greenish-white emitting host Bis-(2-(2-hydroxyphenyl) benzothiazole)zinc (Zn(BTZ)2) is doped with an orange-red fluorescent dye 5,6,11,12-tetraphenylnaphthacene (rubrene). The pure white light emission with CIE coordinates of (0.341, 0.334) is achieved at the driving voltage of 20 V, and the corresponding luminance and external quantum efficiency are 4000 Cd/m2 and 0.63%. On the other hand, the pure red, green, and blue (RGB) emissions are obtained from the white OLED combined well with RGB custom-built optical color filters (CFs) with peaks at 616, 556, and 456 nm, respectively. Moreover, based upon the color mixture principles, we build a model of multi-color display mixed by the pure RGB emissions under the controllable bias. 相似文献
993.
Jin-Fang Nie Hai-Long Wu A-Lin Xia Shao-Hua Zhu Ying-Chao Bian Shu-Fang Li Ru-Qin Yu 《Analytical sciences》2007,23(12):1377-1382
This paper proposes a new and effective approach for the quantitative analysis of sulpiride, a significant antipsychotic drug, in human urine samples by the incorporation of excitation-emission matrix (EEM) fluorescence and second-order calibration methodologies based on the alternating fitting residue (AFR) and self-weighted alternating trilinear decomposition (SWATLD) algorithms. With the application of a second-order advantage, the proposed strategy could be utilized for a direct concentration determination of sulpiride with a simple pretreatment step, even in the presence of serious natural fluorescent interferences. The average recoveries of sulpiride in complex urine samples by using AFR and SWATLD with an estimated component number of three were 101.2 +/- 2.1 and 94.4 +/- 0.7%, respectively. Moreover, the accuracy of the two algorithms was also evaluated through elliptical joint confidence region (EJCR) tests as well as the figures of merit, such as sensitivity (SEN), selectivity (SEL) and limit of detection (LOD). The experimental results demonstrated that both algorithms, as promising quantitative alternatives, have been satisfactorily applied to the determination of sulpiride in human urine, but the performance of AFR was slightly better than that of SWATLD. 相似文献
994.
含Eu3+离子的Na2O-K2 O-SiO2-Al2O3系统玻璃的制备及其变温发射光谱与结构特性 总被引:5,自引:3,他引:2
通过高温熔融法制备了含Eu^3 离子的Na2O-K2O-SiO2-Al2O3系统玻璃。在488nm波长光的激发下,系统地研究了上述玻璃从77K到700K温度范围的变温发光特征。发现总的荧光强度首先随温度的升高而大幅度升高,然后随温度的升高而减少,用声子辅助吸收与热激活过程及温度淬灭效应定性地解释了上述强度的变化,同时测量与分析了Eu^3 离子的晶格场参量。结果表明,Eu^3 离子与氧离子的距离随着温度升高而变短,而Eu^3 离子的配位数不随温度而变化。 相似文献
995.
996.
Ping Li Jian-ming XiaInstitute of System Sciences Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing ChinaInstitute of Applied Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《应用数学学报(英文版)》2002,18(2):349-352
Abstract In this note, we give a characterization of the minimal martingale measure for a general discrete-time incomplete financial market.Then we concretely work out the minimal martingale messure for a specificdiscrete-time market model in which the assets'returns in different times are independent. 相似文献
997.
De‐Xi Yang Shu‐An Li Dong‐Feng Li Wen‐Xia Tang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o11-o13
A novel binucleating 24‐membered macrocyclic ligand, 6,20‐bis(2‐hydroxyethyl)‐3,6,9,17,20,23‐hexazatricyclo[23.3.1.111,15]triaconta‐1(29),11(30),12,14,25,27‐hexaene (L), was synthesized and crystallized as the tetrahydrobromide salt, i.e. 6,20‐bis(2‐hydroxyethyl)‐6,20‐diaza‐3,9,17,23‐hexaazoniatricyclo[23.3.1.111,15]triaconta‐1(29),11(30),12,14,25,27‐hexaene tetrabromide tetrahydrate, C28H50N6O24+·4Br?·4H2O. A crystallographic inversion center is located in the macrocyclic cavity and the two hydroxyethyl pendants are on opposite sides of the macrocyclic plane. The benzene rings of the macrocycle are parallel to each other and a π–π‐stacking interaction exists between the benzene rings of adjacent macrocycles, which are separated by 3.791 (9) Å. An infinite intermolecular hydrogen‐bond network stabilizes the crystal. 相似文献
998.
Xu Rongcong Xia Yonghui 《Annals of Differential Equations》2007,23(4):530-535
In this paper,we investigate the persistence and global asymptotic stability of a discrete predator-prey system.Based on Lyapunov functions,several crite- ria are established concerning the persistence and globally asymptotic stability of difference systems. 相似文献
999.
A new algorithm for real root isolation of univariate polynomials is proposed, which is mainly based on exact interval arithmetic
and bisection method. Although exact interval arithmetic is usually supposed to be inefficient, our algorithm is surprisingly
fast because the termination condition of our algorithm is different from those of existing algorithms which are mostly based
on Descartes’ rule of signs or Vincent’s theorem and we decrease the times of Taylor shifts in some cases. We test our algorithm
on a large number of examples from the literature and report the performance.
相似文献
1000.