检索结果-南通市图书馆

A novel four-component reaction involving ring-opening/recyclization of 1,3-thiazolidinedione

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2010年第4期53卷 863-868页

作者： SUN Jing, XIA ErYan, ZHANG LiLi & YAN ChaoGuo college of chemistry & chemical engineering, Yangzhou university, Yangzhou 225002, china 1. college of chemistry & chemical engineering Yangzhou University Yangzhou 225002 China

The multicomponent reactions of 1,3-thiazolidinedione, malononitrile, aromatic aldehydes and α-phenylethylamine or β-phenylethylamine in acetonitrile at room temperature produce dihydrothiophene ureidoformamide derivatives in moderate yields through a domino ring-opening/recyclization reaction of 1,3-thiazolidinedione. On treatment with DDQ, dihydrothiophenes are dehydrogenated to convert efficiently to thiophenes in the mild condition.

关键词： multicomponent reaction ring-opening recyclization dihydrothiophene thiazolidinedione

SYNTHESIS OF ALCOHOLS FROM HYDROGENATION OF CARBON DIOXIDE(Ⅲ)

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 1994年第3期 348-352页

作者： JI Yuan-Yuan YIN Xiao-LongDepartment, of Applied chemistry taiyuan university of technologyHUANG Wei YIN Li-Hua WANG Chang-YouInstitute of chemistry engineering of Coal taiyuan university of technology taiyuan,Shanxi 030024

The effects of catalyst preparation and reaction conditions on thecatalytic activity and selectivity for hydrogenation of carbon dioxide to alcoholsover zeolite supported bimetal catalyst were *** results showed that:（1）ethanol easily formed on the zeolite with larger pores and methanol did onthat with smaller pores;（2）when pH value of the ion exchange solution was10,the activity reached the maximum;（3）the optimum Cu/Ru mole ratio was3;（4）the influence of reation conditions such as temperature,pressure andH/COmole ratio on the topic reaction was greater.

关键词： OHC HZ CO In Ni MPa SYNTHESIS OF ALCOHOLS FROM HYDROGENATION OF CARBON DIOXIDE

Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china chemistry 2010年第6期53卷 1371-1377页

作者： YANG Tao,JIANG Chen,ZHANG Wei & JIAO Kui Key Laboratory of Eco-chemical engineering,Ministry of Education college of chemistry and Molecular engineering,Qingdao university of Science and technology,Qingdao 266042,china 1. Key Laboratory of Eco-chemical engineering Ministry of Education college of chemistry and Molecular engineering Qingdao University of Science and Technology Qingdao 266042 China

A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys).The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite *** pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH,but also possesses fine biocompatibility for *** probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic *** synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization *** phosphinothricin acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance *** stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3-/4as an indicator.

关键词： poly-L-lysine polyaniline nanotubes DNA electrochemical biosensor PAT gene NOS gene

A thin-layer spectroelectrochemical study of 3,3',5,5'-tetramethylbenzidine at SnO_2:F film optically transparent electrode

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2004年第4期47卷 267-275页

作者： JIAO Kui1, YANG Tao2 & NIU Shuyan1,2 1. college of chemistry and Molecular engineering, Qingdao university of Science and technology, Qingdao 266042, china 2. college of chemistry and chemical engineering, Ocean university of china, Qingdao 266003, china Correspondence should be addressed to Jiao Kui 1. college of chemistry and Molecular engineering Qingdao University of Science and Technology 266042 Qingdao China 2. college of chemistry and chemical engineering Ocean University of China 266003 Qingdao China

The electrooxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) is dependent on the pH value of Britton-Robinson (B-R) buffer solution. In this work, the electrooxidation behavior of TMB was investigated with a SnO2:F film optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process in the pH range from 2.0 to chemical reaction to yield an azo compound. Several spectroelectrochemical techniques, such as thin-layer cyclic voltammetry, thin-layer cyclic voltabsorptometry, thin-layer potential-controlled electrolysis absorptometry, thin-layer single-potential-step chronoabsorptometry, thin-layer dou-ble-potential-step chronoabsorptometry, thin-layer single-potential-step open-circuit relaxation chronoabsorptometry, were applied to this investigation. The formal potential E0’ and the electron transfer number corresponding to the electrooxidation of TMB in B-R buffer solution, and the reaction rate constant of the subsequent chemical reaction were determined.

关键词： 3,3′,5,5′-tetramethylbenzidine tin oxide film optically transparent electrode thin-layer spectroelectro-chemistry electrooxidation

Boron rings containing planar octa- and enneacoordinate cobalt, iron and nickel metal elements

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2008年第7期51卷 607-613页

作者： LUO Qiong School of chemistry and chemical engineering, Central South university, Changsha 410083, china School of chemistry and chemical engineering Central South UniversityChangsha 410083China

For a series of boron rings with planar hyper-coordinate 8th group transition metal atoms, singlet 1FeB8-2, multiplet kFeB9n (n = -1, k = 1; n = 0, k = 2), singlet 1CoB8n(n = -1, +1, +3), multiplet kCoB9n (n = +1, k = 2; n = 0, k = 1) and singlet 1NiB9+, the geometry structures have been optimized to be local minima on corresponding potential hyper-surfaces. The electron structures are discussed by orbital analysis and the aromaticity is predicted by nucleus-independent chemical shifts calculation at both the B3LYP/6-311+G* and BP86/6-311+G* levels of theory, respectively. The results suggest that all these structures with high symmetry planar geometries are stable and have aromatic properties with six π valence electrons.

关键词： planar hyper-coordinate transition metal DFT

Effects of La^(3+) and Eu^(3+) on outward potassium channels in Vicia guard cells

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2009年第11期52卷 1821-1824页

作者： XUE ShaoWu & YANG Pin Key Laboratory of chemical Biology and Molecular engineering of Ministry of Education,Institute of Molecular Science,Shanxi university,taiyuan 030006,china 1. Key Laboratory of chemical Biology and Molecular engineering of Ministry of Education Institute of Molecular Science Shanxi University Taiyuan 030006 China

Effects of La3+ and Eu3+ on outward potassium channels(K+out) in Vicia guard cells have been studied by patch clamping *** La3+ inhibited K+out currents with a half-inhibition concentration(IC50) of 81 μmol·***,intracellular La3+ activated K+out currents at a free concentration of 1.13 × 10-14 mol·L-1,and inhibited K+out currents at a free concentration of 5.86 × 10-14 mol·*** Eu3+ also activated K+out currents at concentrations of 10 μmol·L-1 and 50 μmol·L-1,and inhibited K+out currents at concentrations of more than 1 mmol·*** effects of La3+ and Eu3+ on K+out currents may contribute to regulation of the plant water status,which may be one of the mechanisms of the biological effect of rare earth elements.

关键词： rare earth elements stomata guard cell outward potassium channel

Drag reduction of flow boiling with polymer additives

在线全文

学校读者我要写书评

暂无评论

Journal of Central South university of technology 2001年第2期8卷 143-146页

作者： QIU Yun ren 1,CHEN Wei ping 2,SI Qin 3 (1.college of chemistry and chemical engineering, Central South university, Changsha 410083, china 2.Editorial Office of Journal of Central South university, Changsha 410083, china 3.college of chemical E 1. college of chemistry and chemical engineering Central South University 410083 Changsha China 2. Editorial Office of Journal of Central South university 410083 Changsha China 3. college of chemical engineering Tianjin University 300072 Tianjin China

The drag reducing effect of polymer additive aqueous solution was investigated in flow boiling, and the polymer additives were two kinds of polyacrylamide (PAM) with relative molecular mass about 2.56×10 6 and 8.55×10 6. The frictional pressure drop was calculated according to the measured total pressure drop. The results show that the flow drag of flow boiling is reduced by adding a small amount of PAM to water when heat flux is in the range of 15.1 kW·m -2 to 47.0 kW·m -2 , when the mass fraction of PAM is higher than 2.0×10 -5 , the drag reducing effect is obvious. Drag reducing effect of PAM, whose relative molecular mass is 8.55×10 6, is slightly better than that of 2.56×10 6 at the same mass fraction, and the greater the flow rate of the additive solution, the better the effect of the drag reduction.

关键词： polymer additive flow boiling drag reduction pressure drop

Effect of surfactants on the structure and photoelectric properties of ITO films by sol-gel method

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2010年第2期29卷 143-148页

作者： LIU Jiaxiang, WU Da, ZHANG Nan, and WANG Yue college of Materials Science and engineering, Beijing university of chemical technology, Beijing 100029, china college of Materials Science and engineering Beijing University of Chemical Technology

The Indium tin oxide（ITO） thin film possesses excellent photoelectric properties that enable it to act as an ideal transparent *** obtain high-quality ITO films through sol-gel method, the ionic surfactant monoethanolamine and the non-ionic surfactant polyethylene glycol（PEG） were added to the ITO precursor *** influences of surfactants on the structural and photoelectric properties of ITO film samples were *** patterns indicated that surfactant monoethanolamine contributed to film predominant grain orientation along the（400） *** high transmittance（over 95%） was attributed to the preferred orientation and the grain size expansion of ITO *** showed that the surface particle size and the morphology of ITO films were strongly dependent on the kind of surfactants *** to the shortwave region, the absorption edge of the films exhibited the Burstein-Moss shift.

关键词： surfactants indium tin oxide films sol-gel structure photoelectricity

Cycloaddition mechanism for the resin-OsO_4-catalyzed of styrene: A DFT study

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2008年第1期51卷 19-24页

作者： ZHANG XingHui1, WANG KeTai1 & FANG Ran2 1 college of chemical engineering, Gansu Unite university, Lanzhou 730000, china 2 college of chemistry and chemical engineering, Sun Yat-sen university, Guangzhou 510275, china college of chemical engineering Gansu Unite UniversityLanzhou 730000China college of chemistry and chemical engineering Sun Yat-sen UniversityGuangzhou 510275China

The postulated intermediates in the base-free and base-assisted addition of OsO4 to styrene have been investigated at the B3LYP/6-311G** level of the theory. N(CH3)2(Ph) was chosen as the base of the resin-OsO4. According to our model calculations the [2+3] addition was found to be favorable with an activation of 155.00 kJ/mol). In addition, the electronic structure analysis of the molecules was carried out by na- ture bond orbital (NBO). The computational results were in reasonable agreement with experimental results.

关键词： cycloaddition resin-OsO4 density functional theory