共查询到5条相似文献,搜索用时 0 毫秒
1.
2.
分光光度计是生物化学与分子生物学实验中的常用仪器,常用来测定核酸、蛋白质等生物大分子的纯度、浓度以及吸收光谱的变化特征等。其中纯度与浓度的测定对分光光度计的准确度要求较高,测量数值的细微差异都有可能影响实验结果。因此,提高分光光度计的测量准确度就显得极为重要。本文就作者在这方面的实践经验作一简单介绍。1 确认样品的检测范围在许多情况下,用分光光度计定量的结果不准,往往是因为超出了检测范围。在这里,检测范围包括两方面含义:一是指该样品是否可用分光光度法测定,二是指所测样品的浓度范围。例如,用280nm和260nm紫外… 相似文献
3.
4.
中国对虾体内钴镍含量及其变化规律的研究 总被引:1,自引:0,他引:1
钻(Co)和镍(Ni)是动物生长发育必需的微量元素[1],它们与动物体内许多酶的活性与功能具有密切的联系[2].缺Co将影响维生素B12的合成速度和丙酸的代谢过程;缺Ni则使淀粉酶与肝脏脱氢酶的活性降低,从而影响氨基酸的代谢[3].关于中国对虾(Penaeus chinensis)在生长过程中Co,Ni的含量与变化规律及其相互关系,国内外尚未见报道.笔者采用原子吸收分光光度计测定不同体长的天然对虾和养殖对虾体内Co,Ni的含量,并通过多元分析方法揭示中国对虾在不同生长阶段Co和Ni的变化规律以及它们之间、它们与其体长之间的相互关系. 相似文献
5.
HU Xupeng SU Rongguo ZOU Weiming REN Shijun WANG Hongtao CHAI Xiaoping WANG Yiming 《海洋学报(英文版)》2010,29(4):116-128
The excitation spectra of chlorophyll (Chl) fluorescence can be used to differentiate phytoplankton populations at phylum level in vivo and in situ within a few minutes.The investigated phytoplankton divisions (Dinophyta,Bacillariophyta,Chrysophyta,Cyanophyta,Cryptophyta,Chlorophyta) are each characterized by a specific composition of photosynthetic antenna pigments and,consequently,by a specific excitation spectrum of the Chl fluorescence.Norm excitation spectra (emission of 680 nm and excitation of 400–600 nm) of every division were obtained from several species per division by a F4500 fluorescence spectrophotometer.Fisher’s linear discriminant analysis of the norm spectra shows that the divisions could be discriminated.The discrimination method,established by multivariate linear regression and weighted least squares,was used to differentiate the phytoplankton samples cultured in the laboratory and samples collected from the Jiaozhao Bay at division level.The correctly discriminated samples were more than 94% for single algal species ones,more than 84% for simulatively mixed ones,more than 83% for real mixed ones and 100% for samples collected from the Jiaozhou Bay for the dominant species.The method for phytoplankton differentiation described here can be applied to routine checking by fluorescence spectrophotometer,and benefit the monitoring and supervision tasks related to phytoplankton populations in the marine environments. 相似文献