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941.
CVD法不同条件下制备的多壁碳纳米管的Fenton氧化改性 总被引:2,自引:0,他引:2
碳纳米管经焙烧和稀硝酸纯化处理后,在相同的实验条件下,采用Fenton试剂产生的·OH分别对CVD法合成的两种制备条件不同的多壁碳纳米管进行氧化改性处理。红外光谱(FT IR)表明,改性后的两种碳管结构中都引入了羟基、羰基和羧基等含氧官能团。此外,由于制备条件不同,导致它们的石墨化程度、缺陷含量和抗氧化能力等性质也不同,因此CVD法制备条件能够对碳管Fenton氧化改性结果产生重要影响。机理分析表明,这些含氧官能团可以看作是具有强亲电性和强氧化性的·OH对碳管上缺陷位置和不饱和键进行攻击的结果。 相似文献
942.
Fang-Hui?Wu Guang-Chao?ZhaoEmail author Xian-Wen?Wei Zhou-Sheng?Yang 《Mikrochimica acta》2004,144(4):243-247
Acid-treated multi-walled carbon nanotubes (MWNTs) were immobilized on the surface of a glassy carbon electrode to form an MWNT-modified electrode. The electrocatalytic response of the modified electrode towards tryptophan (Trp) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results demonstrated that the modified electrode exhibited a high degree of catalytic activity towards the oxidation of Trp. An oxidation peak was obtained in Trp solution at the MWNT-modified electrode. Compared with a bare electrode, the peak current had obviously increased, and the peak potential had shifted in a negative direction. However, under the same conditions, no response was observed for other amino acids. The oxidation peak currents were proportional linearly to the concentration of Trp, a property which could be utilized to detect Trp. The determination conditions, such as the concentration, the composition and the pH values of the supporting electrolyte, accumulation time, as well as scan rate etc. were optimized. Under the chosen conditions, the DPV peak current is linear to the concentration of Trp in the range of 2.5×10–7 to 1.0×10–4molL–1, and the detection limit is 2.7×10–8molL–1. Moreover, the detection is free of interference from other amino acids. The modified electrode has been successfully applied to determine the concentration of Trp in composite amino acid injections, and it displays excellent repeatability and higher sensitivity. 相似文献
943.
猴头菇微量元素含量的分析 总被引:5,自引:6,他引:5
用电感耦合等离子体发射光谱仪(ICP-AES)测定了湛江市栽培的猴头茹微量元素的含量,发现其磷、硫、钙、镁、锌、铁、铜等元素的含量都比较丰富,并讨论了这些有益元素与人体健康的关系。 相似文献
944.
945.
We demonstrate the self-assembly of three types of parallel gold nanorod clusters using a rod-like DNA origami as the template. 相似文献
946.
铟锡氧化物纳米网的微波法制备及其光催化特性研究 总被引:2,自引:0,他引:2
By using ultrasonic and chemical liquid coprecipitation, the precursor was prepared with high purity In, SnCl4·5H2O and urea. The In2O3·SnO2 nanonets were obtained from precursor by heating in microwave oven. The powders were characterized by XRD, TEM. The analyzed results show the sample is In2O3·SnO2, and In2O3is rhombohedral system while SnO2 is tetragonal system. The sample is in spherical grain shape, with average granularity of 35 nm, and the mesh diameter of 10~80 nm. The sample was with fluorescence and good photocatalytic performance for degradation of organic dyestuff. 相似文献
947.
A carbon supported Pt-Ru catalyst with uniform distribution and small average size of the Pt-Ru particles was synthesized using a two-step spray pyrolysis (SP) method; the electrocatalytic activity of the prepared catalyst for methanol oxidation is better than that of the standard commercial catalyst. 相似文献
948.
Ab initio valence bond method is employed to quantitatively study the concepts of ionic resonance energy and ionicity of a chemical bond in the cases of hydrides XH(X=Li,Be,B,C,N,O,F) and fluorides XF(X=Li,Be,B),By establishing the relationship between resonance and stability,and comparing the calculated ionicities with Pauling‘s earlier estimations in the above diatomic molecules,the merits of Pauling‘s classical resonance theory were demonstrated at the ab initio level. 相似文献
949.
A series of ferrocenylaldimines (Fc-CH=N-R) has been prepared by Schiff base condensation of formylferrocene with polyacenylamines RNH2 where R = naphthyl, 5,6,7,8-tetrahydronaphthyl, anthracenyl, and pyrenyl groups. This step was followed by oxidation with TCNQ to give [Fc-CH = N-R][TCNQ]2 salts. The electronic state of iron in these compounds was investigated by means of57Fe Mössbauer spectroscopy. 相似文献
950.
Cr(Ⅲ)—5—Br—PADAP—Triton X—100析相光度法测定微量铬的研究 总被引:1,自引:0,他引:1
研究Cr(Ⅲ)-5-Br-PADAP-Triton X-100析相显色体系,建立测定微量铬的析相光度法。在pH 4.5乙酸-乙酸钠介质中,Cr(Ⅲ)、5-Br-PADAP、Triton X-100加热形成的配合物,于95℃恒温浴中析相1h,即被Triton X-100相完全富集,最大吸收峰为593nm,铬含量在0~10μg/5ml服从比耳定律,以硫脲、锰-EDTA、柠檬酸钠、氟化钾为掩蔽剂,测定水样中微量铬,获得满意结果。 相似文献