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91.
ZHOU Ming-Xiua② YANG Chuna DENG Xiao-Yana YU Wei-Feib LI Jin-Shanb a 《结构化学》2006,25(6):647-652
1 INTRODUCTION Silicon and its alloy have been widely applied in such fields as electronic industry, high-temperature structural ceramics, etc. In addition, the researches on silicon and its relevant materials greatly promote the rapid development of modern optics and infor- mation technology. Therefore, more and more at- tention is focused on the structure of silicon, oxide of silicon and the interfaces between silicon and metal or nonmetal. As an ideal passive film on the Si surface, S… 相似文献
92.
两维正交小波基 在许多实际问题中 ,经常会遇到多维的信号 (如图像等 ) ,因此只有一维小波基是不够的。不难证明 (见 [1 ])若φ( t)与Ψ ( t)是小波标准正交基的尺度函数与母函数 ,φjm( x) =2 j2 φ( 2 jx -m) ,Ψjm( x) =2 j2 Ψ ( 2 jx -m) ,则 {Ψjn( x)φjm( y) ,φjn( x)Ψjm( y) ,Ψjn( x)Ψjm( y) }j,m,nz构成两维平方可积函数空间 (即满足∫∞-∞∫∞-∞|f ( x,y) |2 dxdy <∞的全体函数所构成的线性空间 )的一组标准正交基 (见图 1 2 ( a) ( b) )图 1 2(六 )离散小波变换的应用举例( 1 )消除信号中的噪音信号在生成和传输过程… 相似文献
93.
结果表明,LixNi0.3Co0.7O2具有六方晶系R3^-m空间群结构。当X-1,0.315时,其晶胞参数分别为a=2.826nm,c=14.130nm和a=0.2808nm,c=1.4253nm;MO6(M=Ni,Co)八面体中M-O平均距离分别为0。1941nm和0.1933nm。XPS分析结果表明LIxNi0.3CO0.7O2表面存在Li2O,同时探讨了其中过渡金属离子的3d电子结构变化。 相似文献
94.
《中国物理快报》2003,20(10):1871-1874
95.
Efficient Visible Electroluminescence from Porous Silicon Diodes Passivated by Carbon Films
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《中国物理快报》2002,19(7):1013-1015
By using n-butylamine as a carbon resource,carbon film is deposited on the p-n porous silicon (PS) surface with a radio-frequency glow discharge plasma system.Raman spectra and infrared reflection (IR) spectra of the carbon films indicate that there are amine-group and hydrogen atoms therein.The IR spectra of the passivated PS samples exhibit that the PS surfaces are mainly covered with Si-C,Si-N and Si-O bonds.Electroluminescence (EL) spectra show that the EL intensity of the passivated PS diodes increases greatly and the blueshift of the EL peak occurs compared with the diodes without treatment.Both of these are stable while the passivated diodes are exposed to the air indoors.The I-V characteristics reveal that the passivated diodes have a smaller series resistance and a lower onset voltage.The influence of the carbon film passivation on EL properties of PS has also been discussed.The results have proven that carbon film passivation is a good way to enhance the PS luminescent intensity and stability. 相似文献
96.
We show theoretically that it is possible to modify absorption of a bulk absorbing material by inserting another non-absorbing dielectric slab periodically to form one-dimensional photonic crystals.It is found that,for frequencies within photonic bandgaps,absorption is always suppressed.For frequencies located at photonic bands,absorption can be suppressed or enhanced,which depends on the relative values of the real refractive index of the absorbing and non-absorbing dielectric layers. 相似文献
97.
湿度对绝缘体表面电导和气体电导有一定的影响,但通常在湿度传感器的研究中忽略了气体电导的贡献。本文通过特殊设计装置来区分表面电导和气体电导,并分别从实验和理论上进行了定性的研究。 相似文献
98.
A europium complex Eu (DBM)3 TPPO (Eu tris(benzoylmethide)-(triphenylphosphine oxide)) and silicon nanoparticles have been hybridized.The hybridization can evidently change the photoluminescence (PL) characteristics of the Eu complex in the following aspects:under an excitation of 390nm,the intensity of the PL peak at 611nm due to the ^5Du-^7F2 transition of the Eu^3 ions has been increased by 30%,and thc integrated PL intensity in the visible range has been increased by nearly 3 times;the PL excitation efficiency beyond 440nm has been improved cvidently;the peak in the PL excitation spectrum shifts from 408nm to 388nm,and the PL decay time decreases from 2.07 to 0.96μs,The experimental results indicatde that in the PL process,the photoexcited energy may transfer from the silicon nanoparticlcs to the Eu^3 ions. 相似文献
99.
DuXiaCAO QiFANG DongWANG ZhiQiangLIU 《中国化学快报》2003,14(5):547-550
Two new D-x-A type compounds,where electron-donor D is tertiary amino group,electron-acceptor A is 2-benzothiazolyl and x is two conjugated styryl units,have been synthesized.They are named as trans,trans-2-{4-[4-(N,N-diethylamino)styryl]styryl}-1,3-benzothiazole and trans,trans-2-{4-[4-(N,N-diphenylamino)styryl]styryl}-1,3-benzothiazole.Both compounds show strong two-photon excited fluorescence in yellow-orange region when excited by a femtosecond laser at 800nm. 相似文献
100.
The experimental conditions for photoactivated intermittent fluorescence from nanoscale silver oxide were studied with fluorescence microscopy.Strong fluorescence was observed from the Ag2O particles with size of 10-20nm excited with both blue and green light .We observed the saturation of Photoexcitation with blue light and explained the experimental results using the model of agglomeration of silver atoms to form small clusters and the fluorescence of Ag2 and Ag3 clusters. 相似文献