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181.
A novel, sensitive and selective catalytic method for the determination of tungsten is described, based on the W(VI-catalysed redox reaction between methyl red and Ti(III) in a hydrochloric acid medium; methyl red exhibits a sensitive oscillopolarographic wave at −0.68 V vs. SCE in NaOH solution. A calibration graph from 3.2 to 72 ng ml−1 W (detection limit 1.1 ng ml−1) is obtained by the fixed-reaction time procedure. The influence of 29 foreign ions on the catalytic determination of W was examined; none interfered at < 100-fold excess. The method is used to determine W in steel and ore samples, with satisfactory results. 相似文献
182.
一种新多肽表征方法及支持向量机用于肽HPLC定量结构-保留建模预测 总被引:1,自引:0,他引:1
从20种天然氨基酸的1369种性质参数经主成分分析得出一种新多肽序列表征方法——SZOTT. 将其用于71个不同长度肽序列表征, 以偏最小二乘(PLS)和支持向量机(SVM)建立定量结构-保留模型(QSRM). 研究表明, SZOTT能够较好表征71个肽序列特征, 其含信息量大且易操作, 与PLS相比, SVM对lgk建模预测表现出较强的拟合能力和良好外部预测能力, SZOTT表征方法和SVM建模可进一步用于肽HPLC保留行为研究. 相似文献
183.
氨基酸描述子SZOTT用于多肽定量序效建模研究 总被引:1,自引:0,他引:1
在相关研究的基础上, 提出一新的氨基酸描述子SZOTT, 该描述子所含信息量大, 且操作简便. 将其用于两类肽体系序列表征, 用偏最小二乘和正交信号纠正-偏最小二乘建模, 获得较好的建模结果. 相似文献
184.
A series of hyperbranched poly(amine-ester)s based on 1,1,1-trimethylolpropane, methyl acrylate and diethanolamine were synthesized and coated on the inner surface of the fused-silica capillaries by physical adsorption. The most effective coating was the seventh generation hyperbranched poly(amine-ester) coating, which reduced the electroosmotic flow (EOF) greatly and suppressed protein adsorption effectively. The high separation efficiencies for basic proteins were obtained and the coating had a good stability. 相似文献
185.
A kind of 9 nm gold nanoparticles was prepared with the trisodium citrate and used to label goat anti-human IgG to obtain an IgG immunoresonance scattering spectral probe. In pH 5.8 buffer solution and in the presence of polyethylene glycol (PEG), the immune reaction between gold-labeled goat anti-human IgG and IgG took place, and the resonance scattering intensity at 580 nm (I580nm) was enhanced greatly. The enhanced intensity AIRS is pro- portional to the IgG concentration from 1.3 to 1.5 X 10^3 ng.mL^-1, with a detection limit of 0.78 ng.mL ^-1. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum, with satisfactory results. 相似文献
186.
Nitrite has a very strong catalytic effect on the bromate oxidation of Methyl Orange in dilute sulphuric acid medium. The oxidation product of methyl orange exhibits a well derivative voltammetric wave at -0.41 V vs. SCE in sodium hydroxide medium. The linear scan voltammetric behaviour for the product at a DME has been studied, and it was selected as indicator component for the indicator reaction. Based on these studies, a novel and highly sensitive and selective catalytic reaction-voltammetric method for nitrite is proposed. A detection limit of 2 x 10(-9)M and calibration graph from 4 x 10(-7) to 4 x 10(-7)M nitrite are obtained. Nitrite in water samples was determined by this method, with satisfactory results. 相似文献
187.
三角帆蚌(Hyriopsis cumingii Lea)对富营养化水体悬浮物消除的时效模型 总被引:4,自引:0,他引:4
采用三角帆蚌为实验材料,研究其对富营养水体中悬浮物的消除作用,并利用origin软件进行数据分析,以时间(t)为自变量,悬浮物消除率(Er)为因变量,初步建立了不同蚌密度下,三角帆蚌对水体悬浮物消除的时效模型.研究发现,当蚌密度在每立方米6.25个到每立方米31.25个的区间内,时效模型呈具有极大值的抛物线函数.对这些抛物线函数分别过Er=0,0.1,0.5等直线的交点做了数学解析和生物学意义的的探讨.并尝试分析了几个固定时间点下,蚌密度对悬浮物消除率的量效关系. 相似文献
188.
Systematic studies are made on application of chemometrics to chemical modeling and/or molecular modeling as well as the regularity of retention index for gas chromatography (GC). A set of novel molecular graph theoretical parameters, called the molecular distance-edge (MDE) vector (λ), is proposed and found to be excellently correlated to retention index of GC for alkanes. The MDE parameters were tested by the multiple linear regression (MLR) estimation and prediction of the retention index of GC, and the results obtained are satisfactory. 相似文献
189.
190.
柑桔溃疡菌的共振散射光谱 总被引:3,自引:0,他引:3
研究了柑桔溃疡菌的共振散射光谱,在330、425、465和695 nm产生四个共振散射峰.当激发波长为330 nm (9.09×1014 Hz)时,溃疡菌溶液在330 nm(9.09×1014 Hz)、660 nm(1/2×9.09×1014 Hz)和990 nm(1/3×9.09×1014 Hz)分别产生一共振散射峰和1/2、1/3两个分频散射峰;当激发波长为465 nm(6.45×1014 Hz)时,在456 nm(6.45×1014 Hz)和930 nm(1/2×6.45×1014 Hz)分别产生一个共振散射峰和一个1/2分频射峰; 当激发波长为930 nm(3.23×1014 Hz)时,在930 nm (3.23×1014 Hz)、620 nm(3/2×3.23×1014 Hz)、465 nm(2×3.23×1014 Hz) 和310 nm (3×3.23×1014 Hz)分别产生一个共振散射峰,一个3/2分频共振散射峰,一个2倍频共振散射峰和一个3倍频共振散射峰.柑桔溃疡菌是一种非线性散射光学介质.分频散射和倍频散射峰与共振散射峰具有相似的散射行为. 相似文献