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A novel selective fluorescent chemosensor for Cu(Ⅱ)

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Chinese Chemical Letters 2007年第11期18卷 1403-1406页

作者： Mao xiang Wang xiang Ming Meng Man Zhou Zhu qing xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

A novel fluorescence enhancement Cu^2＋ chemosensor derived from coumarin was prepared. Emission study found that it exhibits evident Cu^2＋-arnplified fluorescence prior to Co^2＋, Pb^2＋, Mg^2＋, Mn^2＋, Ni^2＋, Zn^2＋, Fe^3＋, Ag^＋ and Cd^2＋, and the largest emission enhancement factor is about 9 at a ratio of 2：1 （chemosensor 1/Cu^2＋）.

关键词： Cu^2+ chemosensor Fluorescence 荧光性 Coumarin

Novel fluorescent chemosensor for Ag^+ based on coumarin fluorophore

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Chinese Chemical Letters 2008年第8期19卷 977-980页

作者： Mao xiang Wang xiang Ming Meng Man Zhou Zhu qing xiang Guo Department of Chemistry University of Science and Technology of China Hefei 230026 China

A novel chemosensor 1 （CS1） bearing one coumarin and two carbodithioate groups was synthesized and its fluorescent sensing behavior toward metal ions was investigated. Ag^＋ addition to a CH3COCH3/H2O （3：7, v：v） solution of CS1 gave a significantly quenched fluorescence. Other ions including Pb^2＋, Zn^2＋, Cu^2＋, Ca^2＋, Cd^2＋, Co^2＋, Mg^2＋, Mn^2＋, Hg^2＋, Ag^＋, Ni^2＋ induced no or much smaller spectral changes. This constitutes an ON-OFF Ag^＋-selective fluorescent chemosensor.

关键词： Ag^+ chemosensor Fluorescence PET Coumarin

Why a mosquito leg possesses superior load-bearing capacity on water:Experimentals

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Acta Mechanica Sinica 2016年第2期32卷 335-341页

作者： xiang-qing Kong Jian-Lin Liu Cheng-Wei Wu School of Civil and Architectural Engineering Liaoning University of Technology Department of Engineering Mechanics China University of Petroleum Department of Engineering Mechanics Dalian University of Technology

Mosquitoes possess the striking ability to walk on water because each of their legs has a huge water supporting force（WSF） that is 23 times their body *** at a full understanding of the origins of this extremely large force,in this study,we concentrate on two aspects of it：the intrinsic properties of the leg surface and the active control of the initial stepping angle of the whole *** a measurement system that we developed ourselves,the WSFs for the original leg samples are compared with those whose surface wax and microstructures have been removed and with those of a different *** results show that leg f exibility plays a dominant role over surface wax and microstructures on the leg surface in creating the supporting ***,we discuss the dependence relationship between the maximum WSF and the initial stepping angle,which indicates that the mosquito can regulate this angle to increase or decrease the WSF during landing or *** finding are helpful for uncovering the locomotion mechanism of aquatic insects and for providing inspiration for the design of microfluids miniature boats,biomimetic robots,and microsensors.

关键词： Water supporting force Wax coating Surface microstructures Flexibility Initial stepping angle

Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

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Journal of Environmental Sciences 2007年第10期19卷 1266-1271页

作者： XIAO Jun-ping ZHOU qing-xiang BAI Hua-hua Department of Chemistry University of Science and Technology Beijing Beijing 100083 China Henan Key Laboratory for Environmental Pollution Control School of Chemistry and Environmental Sciences Henan Normal University Xinxiang 453007 China

In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes （MWCNTs） and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry. The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing. Parameters influencing the recoveries of target analytes were optimized. Under optimal conditions, the target analyte exhibited a good linearity （R^2=0.9992） over the concentration range 0.5-50 ng/ml. The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%, respectively. The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%. All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.

关键词： multiwalled carbon nanombes (MWCNTs) solid-phase extraction flame atomic absorption spectrometry

Triphenylphosphine-catalyzed isomerization of alkynyl ketones in aqueous solution

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Chinese Chemical Letters 2007年第9期18卷 1029-1032页

作者： qing Fa Zhou Fei Yang qing xiang Guo Song Xue Department of Chemistry University of Science and Technology of China Hefei 230026 China

An efficient isomerization of alkynyl ketones to (E,E)-diene ketones was developed. The reaction catalyzed by 20 mol% triphenylphosphine in aqueous media gave the desired products in good yields.

关键词： Triphenylphosphine Isomerization Alkynyl ketones Water

Binary cyclic codes with two primitive nonzeros

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Science China Mathematics 2013年第7期56卷 1403-1412页

作者： FENG Tao LEUNG KaHin xiang qing Department of Mathematical Sciences Zhejiang University Department of Mathematical Sciences National University of Singapore Department of Mathematical Sciences University of Delaware

In this paper, we make some progress towards a well-known conjecture on the minimum weights of binary cyclic codes with two primitive nonzeros. We also determine the Walsh spectrum of Tr(x d ) over F2m in the case whe... 详细信息

关键词： cyclic code minimum weight Walsh spectrum

Pinacol Coupling Reactions Catalyzed by Active Zinc

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Chinese Chemical Letters 2005年第11期16卷 1459-1462页

作者： Hui ZHAO Wei DENG qing xiang GUO Department of Chemistry University of Science and Technology of China Hefei 230026

Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition, the results indicated that the zinc activity has a direct relation to the coupling reactivity compared to untreated zinc or other general active zinc.

关键词： Pinacol coupling reaction active zinc carbonyl compounds electron transfer.

ESR Studies on N-Alkylphenothiazine Radical Cation Salts

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Chemical Research in Chinese Universities 1995年第3期11卷 195-201页

作者： Guo, qing-xiang Liu, Bo Liu, You-cheng LANZHOU UNIV NATL LAB APPL ORGAN CHEMLANZHOU 730000PEOPLES R CHINA UNIV SCI & TECHNOL CHINA DEPT MODERN CHEMHEFEI 230006PEOPLES R CHINA

he stable radical cation salts of phenothiazine and N-alkyl-phenothiazine(alkyl =methyl , ethyl , isohutyl , isopentyl and benzyl) hexachloroantimonate ,per-chlorate , and iodide were prepared by means of one-electron oxidation with 2 ,2 , 6 ,6-tetramethyl- 4-acetoxypiperidine oxoammonium hexachloroantimonate , perchloricacid, hydrogen peroxide, and molecular iodine, respectively. The radical cationswere characterized using ESR spectroscopy. Conformational analysis based on theESR parameters suggests that the radical cations adopt a planar configuration withthe nitrogen radical as the center.

关键词： Phenothiazine Radical cation salts. ESR spectra

Lp-Solutions of Vector Refinement Equations with General Dilation Matrix

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Acta Mathematica Sinica,English Series 2006年第1期22卷 51-60页

作者： Song LI Ruei Fang HU xiang qing WANG Department of Mathematics Zhejiang University Hangzhou 310027 P. R. China Department of Mathematics Shaoxing University Shaoxing 312000 P. R. China

The purpose of this paper is to investigate the solutions of refinement equations of the form ψ（x）∑α∈Z α（α）ψ（Mx-α）,x∈R, where the vector of functions ψ = （ψ1,..., ψr）^T is in （Lp（R^n））^r, 0 〈 p≤∞, α（α）, α ∈ Z^n, is a finitely supported sequence of r × r matrices called the refinement mask, and M is an s × s integer matrix such that limn→∞M^-n=0, In this article, we characterize the existence of an Lp=solution of the refinement equation for 0〈 p ≤∞, Our characterizations are based on the p-norm joint spectral radius.

关键词： Refinement equation Joint spectral radii Lp-solution