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141.
142.
TheinteractionofquinonephotonucleasewithDNAhasbeenwidelystUdied.Anthraquinonederivatives,inparticularthatofanhraquinone-2-sulfonatehasbeenusedascleavingagentforduPlexDNA1-5.Howevef,directobservationofexcitedionpairsofbiomoleculesespeciallytheStabilizedradicalcationofbiomoleculeishamPeredbytheoverwhelmingtransientabsorPtionofhydrogenbondedradicalanionofquinone.lnthiswork,theinteractionofpolylG]withtripletanthraquinone-2-sulfonateinCH,CN-H:O(97f3)viaelectrontransferreactionhasbeenachieved… 相似文献
143.
Nian Bing LI 《中国化学快报》2000,(8)
IntroductionPolyaniline (PAN) prepared in acidic aqueous media has received a great deal of interestas one of the conductive polymers due to its straightforward methods of preparation andthe stability of its conductive form in airl'2. Its applications as energy storage media3 andas electrochromic device4 have been discussed. But there are few reports about theelectropolymerization of aniline in alkaline solutions.In this paper, we report the results of an ellipsometric study of theelectropol… 相似文献
144.
145.
In the present paper, single‐crystalline lanthanum orthovanadate (LaVO4) nanorods were synthesized by an ethylenediaminetetraacetic acid (EDTA)‐mediated hydrothermal method. The resulting products were characterized using XRD, SEM, TEM and HRTEM. The experimental results illustrated that the morphologies and microstructures of LaVO4 nanorods were influenced by EDTA and pH value of the precursor solution. The magnetic properties measurements showed that the magnetocrystalline anisotropy was greatly strengthened by the strong effect of the one‐dimensional anisotropy, and the magnetic properties of LaVO4 nanorods are better than that of LaVO4 nanoparticles. The growth mechanism of LaVO4 nanorods was also discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
146.
Jiwen Cai Xiaopeng Hu Cai‐Hong Chen Liang‐Nian Ji 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):394-396
The racemic title compound, trans‐[N,N‐bis(2‐aminoethyl)‐1,2‐ethanediamine‐κ4N](dl ‐isoleucinato‐N,O)cobalt(III) diperchlorate, [Co(C6H18N4)(C6H12NO2)](ClO4)2, crystallizes in the enantiomorphous space group P212121 with Z = 12 (Z′ = 3). Each of the three cations in the asymmetric unit represents a different chirality of the isoleucine ligand; two of them are R (or d ) and the third is the S (or l ) enantiomer. The mixture crystallizes in a so‐called unbalanced crystallization, in which the cations adopt a chiral array of composition RRS or SSR, depending on the crystal selected for data collection. 相似文献
147.
Pyramid wavefront sensor (PWFS) is a kind of wavefront sensor with high spatial resolution and high energy utilization. In this paper an adaptive optics system with PWFS as wavefront sensor and liquid-crystal spatial light modulator (LC-SLM) as wavefront corrector is built in the laboratory. The wavefront response matrix is a key element in the close-loop operation. It can be obtained by measuring the real response to given aberrations, which is easily contaminated by noise and influenced by the inherent aberration in the optical system. A kind of analytic solution of response matrix is proposed, with which numerical simulation and experiment are also implemented to verify the performance of closed-loop correction of static aberration based on linear reconstruction theory. Results show that this AO system with the proposed matrix can work steadily in closed-loop operation. 相似文献
148.
固定邻域回归(ANR)算法采用K层奇异值分解(K-SVD)算法进行字典训练, 在字典学习过程中存在稀疏表示系数不准确的问题, 导致重建的结果不理想. 因此, 引入一种改进的K-SVD算法对字典进行训练, 该算法对字典训练改变了传统K-SVD算法更新稀疏表示系数的方式, 使得稀疏表示系数更加准确, 而且加快了字典的收敛速度, 使得训练得到的字典具有更好的稀疏表达能力. 同时, 针对ANR算法的不足, 提出一种面向有限带宽信道基于字典学习的图像超分辨率方法, 该方法采用改进的K-SVD算法训练字典对 , 并将其应用到ANR算法中, 实现图像的超分辨率重建. 实验结果表明, 本文提出的方法不仅能够保持ANR算法快速重建的优势, 而且提高了图像的重建质量, 具有更高的峰值信噪比和结构相似度. 相似文献
149.
Structural Features of a Polysaccharide from Centella asiatica 总被引:3,自引:0,他引:3
Xue Song WANG Jin You DUAN Ji Nian FANG* Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 《中国化学快报》2004,15(2):187-190
Centella asiatica has been used as remedy for sodation, stabilization and against lepra, anabrosis1 in the oriental countries. The low-molecular-weight constituents in Centella asiatica have been investigated1. However, no polysaccharides have been reported. 1BI was the first polysaccharide isolated from C. asiatica, which had immunostimulating activity in vitro. In present study, we report the structural features of 1BI. Experimental Extraction, isolation and purification Dried C.… 相似文献
150.
Ray-Bing Chen Chi-Hsiang Chu Shinsheng Yuan Ying Nian Wu 《Journal of computational and graphical statistics》2016,25(3):665-683
This article proposes a Bayesian approach for the sparse group selection problem in the regression model. In this problem, the variables are partitioned into different groups. It is assumed that only a small number of groups are active for explaining the response variable, and it is further assumed that within each active group only a small number of variables are active. We adopt a Bayesian hierarchical formulation, where each candidate group is associated with a binary variable indicating whether the group is active or not. Within each group, each candidate variable is also associated with a binary indicator, too. Thus, the sparse group selection problem can be solved by sampling from the posterior distribution of the two layers of indicator variables. We adopt a group-wise Gibbs sampler for posterior sampling. We demonstrate the proposed method by simulation studies as well as real examples. The simulation results show that the proposed method performs better than the sparse group Lasso in terms of selecting the active groups as well as identifying the active variables within the selected groups. Supplementary materials for this article are available online. 相似文献