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1.
We present a method requiring no sample preparation for the direct identification of indigoid colorants in tiny amounts in ancient historic fabrics using ASAP®‐MS. Exact determinations were completed in less than 1 min. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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In the present study, two new organic dyes based on indigo were prepared and used as sensitizers in dye-sensitized solar cells. To this end, indoxyl was utilized as the electron-donor and acrylic acid and cyanoacrylic acid were used as the electron-acceptor anchoring groups. These dyes were purified and characterized by analytical techniques. Spectrophotometric evaluations of the prepared dyes in solution and on a nano-anatase-TiO2 substrate were investigated. Additionally, oxidation potential measurements were also carried out. Finally, dye-sensitized solar cells were fabricated to determine the photovoltaic behavior and conversion efficiency of each dye.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]  相似文献   

4.
A comprehensive characterization of the electronic spectral and photophysical properties of the leuco (reduced) form of several indigo derivatives, including indigo and Tyrian Purple, with di‐, tetra‐, and hexa‐substitution, was obtained in solution. The characterization involves absorption, fluorescence, and triplet–triplet absorption spectra, together with quantitative measurements of quantum yields of fluorescence, ?F (0.46–0.04), intersystem crossing, ?T (0.013–0.034), internal conversion, ?IC, and the corresponding lifetimes. The position and degree of substitution promote differences in the spectral and photophysical properties displayed by the investigated leuco derivatives. The ?F values are about two orders of magnitude higher than those previously obtained for the corresponding keto forms. Also in contrast with the behavior found for the keto forms, the S1~~→T1 intersystem crossing is an efficient route for the excited‐state deactivation channel. These findings strengthen the fact that, in contrast to keto indigo where the internal conversion dominates the deactivation of the excited‐state, with leuco indigo (and derivatives), the excited state deactivation involves competition between internal conversion, triplet state formation, and fluorescence. A time‐resolved investigation of one of the compounds in glycerol showed the presence of a photoisomerization process.  相似文献   
5.
 Solid microparticles of several different insoluble organic compounds were mechanically immobilized on the surface of graphite electrodes and immersed into a liquid electrolyte in order to study their electrochemical reactions. Cyclic staircase voltammetry and square-wave voltammetry were used. Quinhydrone was found to be a stable intermediate in the reversible redox reaction of solid quinone and hydroquinone on the electrode surface. The reaction occurs on the surface of the solid particle which is in contact with water. Indigo can be reduced to leucoindigo and oxidized to dehydroindigo in two separate reversible redox reactions. In strongly basic medium indigo dissolves in water upon electroreduction. A hydroacridine radical was detected as a stable intermediate in the electrochemically irreversible redox reaction of acridine and dihydroacridine. Famotidine can be electrooxidized and the product of this reaction can be electroreduced in two separate chemically irreversible reactions. Probucol is oxidized to a semiquinone radical which can be re-reduced in an electrochemically irreversible redox reaction. Propyl- thiouracil can be also oxidized to an unknown product which can be re-reduced in a chemically reversible, but slow solid state surface redox reaction. Reductions of solid thionicotinoylanilide and nicotinoylanilide are totally irreversible. Received September 22, 1998. Revision March 19, 1999.  相似文献   
6.
靛蓝胭脂红-高碘酸钾-草酸钠催化光度法测定钢中微量钒   总被引:5,自引:0,他引:5  
白林山  金斌 《分析化学》2001,29(9):1039-1042
研究了在1 mol/L磷酸介质中,钒(V)对KIO4氧化靛蓝胭脂红褪色反应的催化作用及草酸钠的活化作用,建立了一种测定钒的方法。无草酸钠时该体系为准零级反应,表观活化能为76.7 kJ/mol,在22℃时钒量在0~5mg/L范围内与?A呈线性,检出限为0.1 mg/L。在草酸钠存在下则为准一级反应,表观活化能为60.1 kJ/mol,钒量在0~mg/L范围内与1g(A0/A)呈线性,检出限为0.02mg/L。提高介质酸度,可显著降低反应温度。在NaF及尿素存在下,大多数常见离子无干扰。本法简便快速,选择性和灵敏度较高,用于钢中微量钒的直接测定,结果满意。  相似文献   
7.
In this study, the CuS nanoparticles loaded on activated carbon (CuS‐NPs‐AC) composite was synthesized and then, characterized by XRD and FE‐SEM analyses. The prepared composite was used as a potential adsorbent for the simultaneous ultrasound‐assisted removal of Indigo Carmine (IC) and Safranin‐O (SO). The CuS‐NPs‐AC dose (0.01‐0.03 g), sonication time (1‐5 min), initial SO concentration (5‐15 mg L‐1) and initial IC concentration (5‐15 mg L‐1) as expectable effective parameters were studied by central composite design (CCD) under response surface methodology (RSM) to obtain an useful knowledge about the effect of simultaneous interaction between IC and SO on their removal percentage. The optimum SO and IC removal percentages were determined to be 98.24 and 97.15% at pH = 6, 0.03 g of the CuS‐NPs‐AC, 3 min sonication time, 12 and 10 mg L‐1 of IC and SO. The values of coefficient of determination (R2) for SO and IC were 0.9608 and 0.9796, respectively, indicating the favorable fitness of the experimental data to the second order polynomial regression model. The isotherm data were well correlated with Freundlich model. The maximum monolayer adsorption capacities of 87.5 and 69.90 mg g‐1 at room temperature for IC and SO in the investigated binary system expressed the high efficiency of the novel adsorbent for water cleanup within a short time. The investigation of correlation between time and rate of adsorption revealed that IC and SO adsorption onto the CuS‐NPs‐AC followed pseudo‐second‐order and intra‐particle diffusion simultaneously.  相似文献   
8.
A new Ni(II), Cu(II) and Sn(II) Schiff base complexes were synthesized in this work. The characterization of the new complexes is carried out by elemental analysis, FT‐IR, UV–Visible, 1H NMR and 13C NMR spectroscopy, conductance analysis, magnetic measurements and thermal gravimetric analysis. It was found that the ligand behaves as a dibasic bidentate which coordinated to the metal center through two deprotonated hydroxyl groups to form tetrahedral complex with Ni(II) and octahedral complex with Cu(II). The ligand acts as neutral bidentate through azomethine nitrogen and thiazol sulfur to form octahedral complex with Sn(II). The synthesized complexes are evaluated as catalysts for oxidative degradation of indigo carmine dye using H2O2 as oxidant and the efficiency of the catalysts is determined. The copper complex shows the best catalytic action with efficiency 92.17% after 25 min.  相似文献   
9.
Evidence for access of molecules the size of acetone or pyridine to the intracrystalline tunnels of nanofibre clay (sepiolite) has indicated formation of a new type of organic–inorganic nanocomposites. However, the introduction of larger molecules has been a recurring problem. It is now agreed that for indigo, the molecules are located on the external surface and at the ends of the fibres, thus blocking access to internal tunnels. We claim, however, that it is possible for indigo molecules to access the internal channels of sepiolite. FTIR and XRD analyses have provided evidence for folding of the sepiolite structure preheated at high temperature (above 350 °C). By comparison, we have shown that for indigo/sepiolite mixtures treated in the same conditions, no change in the crystalline structure of the sepiolite is observed, and that blue samples, related to Maya blue, with indigo molecules incorporated deeply enough into sepiolite to prevent folding of the tunnels, can be obtained. NMR, FTIR and thermal analysis confirm the interaction of indigo with the water coordinated to magnesium(II) and located inside the internal and external channels of sepiolite. Two other hypotheses are excluded; we show both that zeolitic water is not blocked in the tunnels by indigo, and that if thermal decomposition products of indigo can be formed, they are in a minority.  相似文献   
10.
邱森  章俭  宋昊  夏春谷 《分子催化》2007,21(5):453-457
萘降解菌LHJ38在金属盐培养基中加入水杨酸钠诱导培养后能提高其生物合成靛蓝的能力,在LB培养基中加入水杨酸钠反而抑制了其生物合成靛蓝的能力.与LHJ38最适生长pH值不同,LHJ38生物合成靛蓝的最佳pH值范围是8.45—9.45,在pH为8.95的情况下生物合成靛蓝能力是其在pH值为6.95的情况下的两倍.  相似文献   
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