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121.
122.
萃取色谱分离稀土元素进展 总被引:6,自引:0,他引:6
评述了近年来我国学者对萃取色谱分离稀土元素各种体系的研究及其在高纯稀土分离方面的应用,并对高纯稀土制备的发展方向进行了展望。 相似文献
123.
调查了内蒙古青山区8~10岁儿童碘缺乏病甲状腺肿大率,结果表明,甲状腺肿大率为19.6%,且以城乡结合部居住儿童为高,监测了其尿碘,尿碘水平100μg/L以下者为11.2%,其中50μg/L者了有发现,据此情况,今后仍要强化防治工作。 相似文献
124.
流动注射化学发光免疫分析研究II. 偶合反应测定HRP及其标记 物 总被引:1,自引:0,他引:1
本文详细考查了壳质胺,多孔玻璃和粗孔硅胶作为流动注射免疫分析免疫反应器基质的可行性,在此基础上将HRP催化H~2O~2氧化K~4Fe(CN)~6生成K~3Fe(CN)~6的反应,与H~2O~2和K~3Fe(CN)~6对luminol的共氧化化学发光反应相偶合首次提出了一种新的流动注射免疫分析的最终检测手段,由于酶促反应与化学发光反应在检测系统的不同位置进行,因而这种方法克服了已报道的流动注射化学发光免疫分析不能协调酶催化和化学发光反应的最佳pH,底物与酶不能充分接触及载体对光的散射等缺点,具有灵敏度高、精密度好等优点,该方法测定HRP及其标记物检测限均可达fmol级,测定时间为1-2min,相对标准偏差为3.9%。 相似文献
125.
Yuyu Sun Zhengzhong Shao Ping Hu Tongyin Yu 《Journal of Polymer Science.Polymer Physics》1997,35(9):1405-1414
FT–IR spectroscopy was used to study the specific interactions in polyacrylonitrile-silk fibroin (PAN–SF) and poly(acrylonitrile-co-methyl acrylate)-silk fibroin (PANMA–SF) blends. No specific interaction was found in PAN–SF blends. In PANMA–SF blends, however, a new 1703 cm−1 band, assigned to be hydrogen-bonded carbonyl groups of PANMA, appears, and its intensity depends on the compositions of the blends and the MA contents in PANMA. Furthermore, when the sample was heated, considerable changes in position and intensities of the hydrogen-bonded bands, in both stretching regions of the carbonyl group of PANMA and the hydroxl group of SF, were found, and these changes were irreversible on cooling. Finally, we suggested that the bands of hydrogen bonds in PANMA–SF blends may be the average result of several kinds of possible hydrogen bondings. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1405–1414, 1997 相似文献
126.
Jing Jin Yi-Qing Lv Wei-Zhong He Da Li Ying Ye Zai-Fa Shu Jing-Na Shao Jia-Hao Zhou Ding-Mi Chen Qing-Sheng Li Jian-Hui Ye 《Molecules (Basel, Switzerland)》2021,26(23)
Both UV and blue light have been reported to regulate the biosynthesis of flavonoids in tea plants; however, the respective contributions of the corresponding regions of sunlight are unclear. Additionally, different tea cultivars may respond differently to altered light conditions. We investigated the responses of different cultivars (‘Longjing 43’, ‘Zhongming 192’, ‘Wanghai 1’, ‘Jingning 1’ and ‘Zhonghuang 2’) to the shade treatments (black and colored nets) regarding the biosynthesis of flavonoids. For all cultivars, flavonol glycosides showed higher sensitivity to light conditions compared with catechins. The levels of total flavonol glycosides in the young shoots of different tea cultivars decreased with the shade percentages of polyethylene nets increasing from 70% to 95%. Myricetin glycosides and quercetin glycosides were more sensitive to light conditions than kaempferol glycosides. The principal component analysis (PCA) result indicated that shade treatment greatly impacted the profiles of flavonoids in different tea samples based on the cultivar characteristics. UV is the crucial region of sunlight enhancing flavonol glycoside biosynthesis in tea shoots, which is also slight impacted by light quality according to the results of the weighted correlation network analysis (WGCNA). This study clarified the contributions of different wavelength regions of sunlight in a field experiment, providing a potential direction for slightly bitter and astringent tea cultivar breeding and instructive guidance for practical field production of premium teas based on light regimes. 相似文献
127.
128.
Lesaicherre ML Lue RY Chen GY Zhu Q Yao SQ 《Journal of the American Chemical Society》2002,124(30):8768-8769
We report here the first example using an intein-mediated expression system to generate biotinylated proteins suitable for immobilization onto avidin-functionalized glass slides. With this novel array, proteins are site-specifically immobilized on the glass surface and are able to retain their native activity. The advantage of the avidin/biotin linkage over his-tag/Ni-NTA strategies for protein immobilization is highlighted by its ability to withstand a variety of chemical conditions, which makes this new protein array compatible with most biological assays. 相似文献
129.
Nanosized surface-enhanced Raman scattering (SERS) substrates fabricated by the controlled growth of metal nanostructures on water-dispersed two-dimensional nanomaterials can open a new avenue for SERS analysis of liquid samples in biological fields. In this work, regular and uniform Ag nanostructures were grown on the surface of graphene oxide (GO) through a microwave-assisted hydrothermal method. Polyamidoamine (PAMAM) dendrimers were assembled on the surface of GO to form GO/PAMAM templates for growing Ag nanostructures, which are primarily comprised of Ag dimers and trimers. The prepared Ag/GO nanocomposites are highly dispersed and stable in aqueous solution and may be used as substrates for enhanced Raman detection of rhodamine 6?G (R6G) in aqueous solution. This special substrate provides high-performance SERS and suppresses R6G fluorescence in aqueous solution and is promising as a nanosized material for the enhanced Raman detection of liquid samples in biological diagnostics. 相似文献
130.
Shao‐Dong Su Xiao‐Quan Zhu Yue‐Hong Wen Lin‐Tao Zhang Yu‐Ying Yang Chen‐Sheng Lin Xin‐Tao Wu Tian‐Lu Sheng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15488-15492
An unusual tetra‐nuclear linear cyanido‐bridged complex [Ru2(μ‐ap)4‐CN‐Ru2(μ‐ap)4](BPh4) ( 1 ) (ap=2‐anilinopyridinate) has been synthesized and well characterized. The crystallographic data, magnetic measurement, IR, EPR and theoretical calculation results demonstrate that complex 1 is the first example of mixed spin Ru25+‐based complex with uncommon electronic configurations of S=1/2 for the cyanido‐C bound Ru25+ and S=3/2 for the cyanido‐N bound Ru25+. This phenomenon can be understood by the theoretical calculation results that from the precursor Ru2(μ‐ap)4(CN) (S=3/2) to complex 1 the energy gap between π* and δ* orbitals of the cyanido‐C bound Ru25+ core increases from 0.57 to 1.61 eV due to the enhancement of asymmetrical π back‐bonding effect, but that of the cyanido‐N bound Ru25+ core is essential identical (0.56 eV). Besides, the analysis of UV/Vis‐NIR spectra suggests that there exists metal to metal charge transfer (MMCT) from the cyanido‐N bound Ru25+ (S=3/2) to the cyanido‐C bound Ru25+ (S=1/2), supported by the TDDFT calculations. 相似文献