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991.
J.P. Zou Y.F. Mei J.K. Shen J.H. Wu X.L. Wu X.M. Bao 《Applied Physics A: Materials Science & Processing》2003,77(6):855-858
A SiO2 nanoscale island array was fabricated on a Si substrate by using anodic porous alumina as a mask. Transmission electron microscopy observation and the atomic force microscopy pattern show that the arrangement of SiO2 islands has a quasi-hexagonal symmetry. Ge ions with a dose of 1×1017 cm-2 were subsequently implanted into the SiO2 island array to form Ge-related light-emitting centers. The photoluminescence (PL) spectra of as-implanted and annealed samples show three PL bands at 370, 400 and 415 nm. Their intensities reach maximums in the sample with an annealing temperature of 700 °C. Spectral analysis suggests that the 370 and 415 nm PL bands arise from Ge-Ge and Ge-Si defect centers, while the 400 nm PL is related to GeO color centers in the SiO2 islands. The existence of these PL bands indicates the formation of a Si-based nanoscale light source array. PACS 78.55.Mb; 42.72.Bj; 68.65.+g 相似文献
992.
M. Zhou Y.K. Zhang L. Cai J.Z. Zhou Z.H. Shen X.R. Zhang S.Y. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(7):1113-1116
In this communication, we report a numerical model that predicts the mechanical deformations associated with the pulsed laser
irradiation of a film surface, based on thermal diffusion theory. The model is consequently advanced to produce a method for
evaluating film adhesion strength. The epicenter surface displacements within the irradiated fields have been measured using
a heterodyne interferometer. The comparison of the experimental data and the displacements calculated by the model shows good
agreement. By investigating the propagating acoustic modes under non-destructive and destructive modes, we reveal that, with
or without interface delamination, the phase structure of the longitudinal waves will be altered due to the change of reflection
mode at the interface. Applying shock dynamics theory, we evaluate the adhesion strength of the TiN/stainless interface. We
also indicate the strain rate can be up to 105∼106 s-1 during film interface delamination.
Received: 5 April 2002 / Accepted: 24 June 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax: +86-511/879-1919, E-mail: mzhou@ujs.edu.cn 相似文献
993.
Shen J 《Journal of chemical information and computer sciences》2003,43(5):1668-1672
Collecting, organizing, and reviewing chemical information associated with screening hits are human time-consuming. The task depends highly on the individual, and human errors may result in missing leads or wasting resources. To overcome these hurdles, we have developed a decision support system, Hits Analysis Database (HAD). HAD is a software tool that automatically generates an ISIS database file containing compound structures, biological activities, calculated properties such as clogP, hazard fragment labels, structure classifications, etc. All data are processed by available software and packed into a single SD file. In addition to search capabilities, HAD provides an overview of structural classes and associated activity statistics. Chemical structures can be organized by maximum common substructure clustering. The ease of use and customized features make HAD a chief tool in lead selection processes. 相似文献
994.
Fractionation of the ethanolic extract of the seeds of Calophyllum inophyllum L. has resulted in the isolation of four novel pyranocoumarin derivatives, designated as inocalophyllins A (1), B (2) and their methyl esters (3, 4) in addition to the known calophyllolide. The structures of these compounds have been determined on the basis of spectroscopic analysis including MS, heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and two dimensional incredible natural abundance double quantum transfer experiment (2D-INADEQUATE). Two new methylated products, 5 and 6 were also prepared by methylation of compounds 1 and 2, respectively. 相似文献
995.
Chen Cs Ran S Liu W Yang Ph Peng Dk Bouwmeester HJ 《Angewandte Chemie (International ed. in English)》2001,40(4):784-786
996.
Shuping Zhuo Jichong Wei Changsheng Shen Guanzhi Ju 《International journal of quantum chemistry》2001,83(6):311-317
In this article, the transferable property of pair correlation energies of OH components is discussed for a series of OH containing compounds MOH (M=H, Li, Na). In this series of compounds, from OH free radicals through HOH, LiOH, NaOH to OH?, both the intra‐ and interpair correlation energies and intra‐ and intershell correlation energies of the inner orbital electrons change little. The 1s$_{\mathrm{O}}^{2}$ is very much alike in all the above OH containing systems and such a pair correlation is transferable. But the interpair correlation and intrashell correlation energies of the valence electrons are large and change a lot in all systems. In MOH molecules, the OH correlation energy contribution increases with the increase of the ionic bond strength of the compound and this contribution is always between the correlation energy values of OH free radicals and OH? atomic groups. For strong ionic compounds, we present a very simple method to estimate the correlation energy by adding the correlation energies of its component ions within the chemical accuracy (2 kcal/mol). © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 311–317, 2001 相似文献
997.
: Multiple electron transfer processes are studied for Arq+n- Ne (q= 8, 9, 11, 12) collisions by using multi-parameter coincidence techniques. Various electron transfer processes are identified experimentally and the related cross-sections are measured. The dependence of transfer ionization cross-sections on the recoil charge states is compared with the results from the modified molecular classical overbarrier model. It is found that the modified model described the experimental results reasonably. 相似文献
998.
The existence of infinitely many solutions of the following Dirichlet problem for p-mean curvature operator:
is considered, where Θ is a bounded domain in R
n
(n>p>1) with smooth boundary ∂Θ. Under some natural conditions together with some conditions weaker than (AR) condition, we prove that the above problem
has infinitely many solutions by a symmetric version of the Mountain Pass Theorem if
.
Supported by the National Natural Science Foundation of China (10171032) and the Guangdong Provincial Natural Science Foundation
(011606). 相似文献
999.
The Spherical Code (SC) problem has many important applications in such fields as physics, molecular biology, signal transmission, chemistry, engineering and mathematics. This paper presents a bilevel optimization formulation of the SC problem. Based on this formulation, the concept of balanced spherical code is introduced and a new approach, the Point Balance Algorithm (PBA), is presented to search for a 1-balanced spherical code. Since an optimal solution of the SC problem (an extremal spherical code) must be a 1-balanced spherical code, PBA can be applied easily to search for an extremal spherical code. In addition, given a certain criterion, PBA can generate efficiently an approximate optimal spherical code on a sphere in the n-dimensional space
n. Some implementation issues of PBA are discussed and putative global optimal solutions of the Fekete problem in 3, 4 and 5-dimensional space are also reported. Finally, an open question about the geometry of Fekete points on the unit sphere in the 3-dimensional space is posed. 相似文献
1000.
Collection-mode near-field scanning optical microscopy (NSOM) is used to map nanoscopic second-harmonic generation (SHG) in N -(4-nitrophenyl)- (L) -prolinol crystals. A spatial resolution of 98 nm is achieved. Near-field polarization-dependent SHG measurement is performed, and a local effective SHG susceptibility of 224+/-18 pm/V is obtained. 相似文献