排序方式: 共有35条查询结果,搜索用时 14 毫秒
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中药肝豆汤治疗铜代谢障碍疾病具有疗效显著、副作用小的优势,但由于缺乏评价铜离子(Cu2+)络合能力的技术手段,限制了肝豆汤配位活性成分的筛查和发现。为评价复方肝豆汤中主药大黄对铜离子的络合能力,该文通过优化大黄活性成分与铜离子配位反应条件,建立了超高效液相色谱法(UHPLC)测定中药大黄与铜离子络合能力的方法。样品经Agilent Eclipse Plus C18色谱柱(50 mm×2.1 mm, 1.8μm)分离,以甲醇-0.1%(v/v)磷酸水溶液为流动相进行梯度洗脱,柱温30℃,流速为0.3 mL/min,检测波长为254 nm,进样体积为5μL。研究通过UHPLC分析比较大黄与铜离子配位反应前后色谱峰变化,超高效液相色谱四极杆-飞行时间质谱(UPLC-Q-TOF-MS)鉴定大黄提取物中配位活性成分,计算大黄提取物与铜离子配位反应前后其色谱峰面积变化率来评价大黄中活性成分与Cu2+的络合能力。结果显示,大黄提取物与Cu2+在pH为9的体系中配位反应12 h达到平衡;鉴定出大黄提取物中20种主要成分,根据Cu 相似文献
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利用同步辐射光电子能谱(SRPES)和X射线光电子能谱(XPS)技术,系统研究了室温下Fe/ZnO界面形成过程中Fe薄膜与氧结尾的ZnO(000 1 )衬底之间的相互作用,结果显示初始沉积的Fe明显被表面氧氧化为Fe2+离子,在Fe覆盖度为0—3 nm的范围内,分别观察到与界面电荷传输、化学反应以及薄膜磁性相关的三个有意义的临界厚度,这一结果将有助于基于Fe/ZnO界面的相关器件的设计和研发. 相似文献
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β-环糊精功能化聚丙烯腈纳米纤维的制备及对亚甲基蓝的吸附性能 总被引:1,自引:0,他引:1
以N,N-二甲基甲酰胺(DMF)为溶剂,利用静电纺丝法制备了聚丙烯腈(PAN)/β-环糊精(β-CD)纳米纤维.通过场发射扫描电镜、红外光谱和粉末XRD对纳米纤维进行了表征,并检测了纺丝溶液的电导率和黏度.结果表明,β-CD的添加量可以改善纳米纤维的形貌,固定在纤维上的β-CD保留了空腔结构,为其在纳米纤维中发挥超分子... 相似文献
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Detection of Fe 3d electronic states in valence band and magnetic properties of Fe-doped ZnO film 下载免费PDF全文
Fe-doped ZnO film has been grown by laser molecular beam epitaxy (L-MBE) and structurally characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), all of which reveal the high quality of the film. No secondary phase was detected. Resonant photoemission spectroscopy (RPES) with photon energies around the Fe 2p-3d absorption edge is performed to detect the electronic structure in the valence band. A strong resonant effect at a photon energy of 710 eV is observed. Fe3+ is the only valence state of Fe ions in the film and the Fe 3d electronic states are concentrated at binding energies of about 3.8 eV and 7 eV~ 8 eV. There are no electronic states related to Fe near the Fermi level. Magnetic measurements reveal a typical superparamagnetic property at room temperature. The absence of electronic states related to Fe near the Fermi level and the high quality of the film, with few defects, provide little support to ferromagnetism. 相似文献