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排序方式: 共有2213条查询结果,搜索用时 15 毫秒
961.
In this paper, a novel modified electrode was developed by using highly dispersed Prussian blue (PB) nanoparticles protected by poly(vinylpyrrolidone) (PVP). The size of the nanoparticles was controlled through adjusting the feed ratio of PVP/Fe2+. Physical characteristics of the nanocomposite were studied by transmission electron microscopy (TEM), UV-vis, IR spectroscopy, and X-ray powder diffraction (XRPD) analysis. The electrocatalytic reduction of hemoglobin (Hb) at PVP-protected PB nanoparticles (PVP/PB NPs)-modified electrode had been investigated. In addition, the size effects and biocompatibility of PVP/PB NPs for the electrochemistry of Hb were also observed. Experimental results indicated that the reduction peak currents of Hb were linear with its concentrations over the range from 1.0 × 10−7 to 1.2 × 10−5 mol/L and the calculated detection limit (S/N = 3) was 4.0 × 10−8 mol/L. 相似文献
962.
Batch adsorption experiments were carried out for the removal of methylene blue (MB) from aqueous solution using attapulgite as adsorbent. The effects of various parameters such as temperature, contact time, the pH value, and attapulgite dosage on the adsorption performance were investigated. The standard curve and regression equation were established by spectrophotometry. The adsorption experimental results showed that the adsorption equilibrium data were well in accord with Langmuir adsorptive model. The optimal result was acquired under the experimental condition of attapulgite dosage 0.18g, MB concentration 50.0mg/L, pH 10, and adsorption time 20min at room temperature. 相似文献
963.
The recent discovery of the salutary effects of carbon monoxide (CO) in chronic obstructive pulmonary disease (COPD), ischemic perfusion damage, graft implantation, as well as its pro-apoptotic effects on hyper-proliferating cells has raised interest in delivering small doses of CO to biological targets under controlled conditions. In such attempts, photoactive metal carbonyl complexes (photoCORMs) have shown promise and several accounts of cancer cell eradication with light-triggered CO release from photoCORMs have been reported. CO releasing molecules (CORMs) and photoCORMs have been incorporated within biocompatible drug delivery vehicles such as carboxymethyl chitosan or mesoporous silica-based nanoparticles and the composite materials (photoCORs) have been successfully employed in controlled CO delivery to cancer cells to cause rapid CO-induced apoptosis. Fiber optic technology has also been utilized for remote delivery of CO to not easily accessible targets. Reports on all these therapeutic modalities for on-demand CO delivery to malignant targets in a highly localized fashion have opened up the possibility of phototherapy of cancer with the use of an unusual so-called “toxic” molecule. This review highlights the methodologies used in CO photochemotherapy reported so far along with analysis of their therapeutic outcomes, and possible improvements for better applicability. 相似文献
964.
以乙醇为溶剂, 钛酸四丁酯为前驱体, 用溶剂热法制备了Ag表面修饰的负载型纳米二氧化钛光催化剂. 利用X射线衍射(XRD)、N2吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外-可见(UV-Vis)光谱等技术对其进行了系统的表征, 以亚甲基蓝(MB)溶液的脱色降解为模型反应, 考察了不同Ag含量样品的光催化性能. 结果表明: 用溶剂热法制备的样品中TiO2皆为锐钛矿相, 金属Ag颗粒沉积在TiO2表面, 粒径为2 nm左右, 比表面积较溶胶凝胶法制备的样品大大增加, 最高可达151.44 m2·g-1; UV-Vis光谱和光催化实验表明: Ag修饰使TiO2对光的吸收能力大大增强, 吸收带边红移至可见光区, 亚甲基蓝在该复合材料上的光催化降解反应遵循一级反应动力学模型; 溶剂热法制备样品的光催化性能明显好于溶胶凝胶法制备的样品, 在紫外光和可见光下, Ag摩尔分数为5%的样品表现出最佳的光催化活性. 相似文献
965.
We have determined the optimal conditions for synthesis of Bi2S3/CdS nanocomposites and we have determined their photocatalytic activity in the reaction of reduction of methylene blue as a function of composition. We suggest a possible mechanism for the photocatalytic action of the nanocomposites. 相似文献
966.
Jing-Jing Yu Shuang Lu Jiang-Wen Li Fa-Qiong Zhao Bai-Zhao Zeng 《Journal of Solid State Electrochemistry》2007,11(9):1211-1219
This study reports the preparation and characterization of gold nanoparticles deposited on amine-functioned hexagonal mesoporous
silica (NH2–HSM) films and the electrocatalytic oxidation of glucose. Gold nanoparticles are fabricated by electrochemically reducing
chloroauric acid on the surface of NH2–HSM film, using potential step technology. The gold nanoparticles deposited have an average diameter of 80 nm and show high
electroactivity. Prussian blue film can form easily on them while cycling the potential between −0.2 and 0.6 V (vs saturated
calomel electrode) in single ferricyanide solution. The gold nanoparticles loading NH2–HSM-film-coated glassy carbon electrode (Au–NH2–HSM/GCE) shows strong catalysis to the oxidation of glucose, and according to the cathodic oxidation peak at about 0.16 V,
the catalytic current is about 2.5 μA mM−1. Under optimized conditions, the peak current of the cathodic oxidation peak is linear to the concentration of glucose in
the range of 0.2 to 70 mM. The detection limit is estimated to be 0.1 mM. In addition, some electrochemical parameters about
glucose oxidation are estimated. 相似文献
967.
Cecile F. Rousseau Sebastien Cecillon Eric Da Silva Anne-Marie Freyria Daniel Herbage Edwige Leclere Anthony W. Coleman 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(1-2):9-13
A spectrometric assay for the determination of concentration of para-sulphonato-calix[n]arenes and their derivatives has been developed using dimethylmethylene blue (DMMB) as a probe. Interaction with para-sulphonato-calix[n]arenes leads to a metachromatic shift in the spectrum of DMMB with appearance of a peak at 536 nm and diminution of the spectral
intensity of the peaks at 594 and 649 nm. The method shows good linearity in the concentration range 0–6 μg/ml for para-sulphonato-calix[n]arenes.
in final form: 27 December 2004 相似文献
968.
Yi-Feng?TuEmail author Jun-Wei?Di Xiao-Jun?Chen 《Journal of Sol-Gel Science and Technology》2005,33(2):187-191
This paper reports a new method to make the sol–gel film from silicate. It provided more profitable conditions than hydrolysis of alkoxyl silane to prepare the high-quality nanometers thin film. The thin film could be applied as the matrix to directly modify the molecules of methylene blue on electrode surface and kept their electrochemical activity excellently. It exhibited the remarkable catalytic activity for the oxidation of NADH or reduction of hemoglobin while severally embedding them in the sol–gel film together with methylene blue. 相似文献
969.
本文研究普鲁士蓝(PB)膜修饰电极的循环伏安行为,结果表明,膜中电活性中心间的相互作用导致PB膜电极的伏安行为偏离理想表面波.用有限扩散边界模型解释了高电位扫速下膜电极的伏安行为.在含钾离子的电解质溶液中测得PB膜中电荷传输扩散系数为10~(-9)~10~(-11)cm~2/s. 相似文献
970.
新型杂多蓝化合物[NH_3(CH_2)_2NH_3]_5[Cd(H_2O)][CdMo_(12)~ⅤO_(30)(HPO_4)_6(H_2PO_4)_2]·5H_2O的合成与晶体结构 总被引:2,自引:0,他引:2
利用水热法首次合成了具有两种配位环境Cd原子的新型杂多蓝化合物[NH3(CH2)2NH3]5[Cd(H2O)][CdMo12ⅤO30(HPO4)6(H2PO4)2].5H2O.通过元素分析I、CP、TG和X射线单晶衍射确定了其组成,使用IR和EPR进行了结构表征.通过N2吸附脱附测定了比表面积和孔径,为催化研究提供了基础数据.结果表明:该晶体为三斜晶系,P-1空间群;晶胞参数a=1.200 2(2)nm,b=1.465 1(3)nm,c=2.119 2(4)nm,V=3.564 2(12)nm3,β=83.01(3)°,Z=2,F(000)=293 2,R1=0.030 0,wR2=0.071 6. 相似文献