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首先合成配合前驱体对氨基苯甲酸(PABA)-二乙烯三胺五乙酸(DTPA)-3-氨丙基三甲氧基硅烷(APTMS)及双稀土配合物Eu3+/Tb3+-PABA-DTPA-APTMS,然后采用反相微乳液法成功制备出表面带氨基的核壳型稀土配合物Eu3+/Tb3+-PABA-DTPA-APTMS掺杂的Ag@SiO2荧光纳米粒子.利用透射电子显微镜、荧光光谱、紫外-可见光谱等手段进行表征,并进行了光稳定性及氨基测定等实验,结果表明,该纳米粒子中Eu3+与Tb3+在最大发射峰处的荧光强度较Eu3+/Tb3+-PABA-DTPA-APTMS掺杂的没有银核的SiO2荧光纳米粒子分别提高了3.0和3.4倍,所制备的纳米粒子呈规则球状,具有良好的分散性和光稳定性,纳米粒子表面带有氨基,可不需要进行表面修饰而直接与生物分子反应.该纳米粒子有望作为一种新型的稀土荧光探针应用于高灵敏检测的时间分辨荧光免疫分析、生物传感器、生物芯片等. 相似文献
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Ti incorporated amorphous carbon (a-C) films with variant Ti contents were prepared by the unbalanced magnetron sputtering process. Scanning electron microscopy, ultraviolet Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy were used to characterize the microstructure of a-C films. The hardness and lubricated tribological properties were assessed using nanoindentation and ball-on-disk tribometer. As the Ti content in a-C films increases from 0 to 15.2 at.%, the sp3 volume fraction, the internal stress and the hardness of the films decreases gradually, while the disorder of sp2 bond increases. The electrochemical tests reveal that the a-C films with lower than 1.5 at.% Ti possess good corrosion resistance in Hanks’ solution, while the a-C film with 15.2 at.% Ti is susceptible to crevice corrosion. The reduced friction of the a-C films is due to the sp2 bonded film surface and boundary lubrication of the Hanks’ solution. The a-C film with 3.1 at.% Ti exhibits the best wear resistance in Hanks’ solution among the studied films. 相似文献
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Yin Dongguang Liang Yufu Miao Zengsheng Li Baolong Bai Chunqi Luo Zhifu 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(3):629-631
The separation of gram quantities of uranium from fission products has been investigated by extraction chromatography. The separation which is based on the difference in distribution coefficients between uranium and the fission products on a tributyl phosphate (TBP) resin in nitric acid medium, was carried out by means of high acidity feed and stepwise elution on a TBP chromatography column. The results show that this technique is capable to separate 5 g of uranium from a large quantity of fission products. The recovery of uranium is more than 99%. The decontamination factors of g- and b-activities were 2.1.103 and 2.3.103, respectively. 相似文献
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Ethanol productions from cheese whey powder (CWP) solution were investigated by using free or immobilized cells of Kluyveromyces marxianus in monocultures or mixed cultures with free or immobilized cells of K. marxianus and Saccharomyces cerevisiae. K. marxianus free cells produced 3.8% v/v ethanol in monocultures, while S. cerevisiae immobilized cells produced 5.3% v/v ethanol in mixed cultures. The percentage of theoretical yield was found to be higher in mixed cultures than that in monocultures.
The maximum ethanol fermentation efficiency was achieved (79.9% of the theoretical value) using mixed cultures of immobilized
cells of K. marxianus and S. cerevisiae. The beads were relatively stable without significant reduction in activity for about eight batches of fermentation. 相似文献
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Ethanol tolerance is a key trait of microbes in bioethanol production. Previous studies have shown that soya flour contributed
to the increase of ethanol tolerance of yeast cells. In this paper, the mechanism of this ethanol tolerance improvement was
investigated in cassava ethanol fermentation supplemented with soya flour or defatted soya flour, respectively. Experiment
results showed that ethanol tolerance of cells from soya flour supplemented medium increased by 4–6% (v/v) than the control with defatted soya flour. Microscopic observation found that soya flour can retain the cell shape while
dramatic elongations of cells were observed with the defatted soya flour supplemented medium. Unsaturated fatty acids (UFAs)
compositions of cell membrane were analyzed and the UFAs amounts increased significantly in all tested strains grown in soya
flour supplemented medium. Growth study also showed that soya flour stimulated the cell growth rate by approximately tenfolds
at 72-h fermentation. All these results suggested that soya fatty acids play an important role to protect yeast cells from
ethanol stress during fermentation process. 相似文献
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