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We described herein a concise synthesis of 3',4'-diaminoflavone 10. This new, three-step synthetic approach is more efficient than the conventional seven-step synthetic method. The route is shortened significantly by introducing the amino moieties early and eliminating the need for nitro group reduction. The other two analogues, 5,7-dihydroxy-3',4'-diaminoflavone 11 and 5,7-dimethoxy-3',4'-diaminoflavone 12, were also synthesized similarly. The above three compounds, along with flavone, were evaluated for their antioxidant and UVB-protection abilities on zebrafish larvae. The data showed that compound 10 exhibited the best result, with -102.3% of ROS-scavenging rate. 相似文献
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衍射增强相位衬度成像中的信息分离研究一直以来都是相关研究人员重点关注的方向之一. 本文在利用余弦函数拟合衍射增强成像中的摇摆曲线的基础上, 推导出了峰位像、左腰像和右腰像的余弦函数表达式以及吸收像、折射角像和散射角方差像的解析表达式, 形成了一种基于衍射增强成像的简便信息分离方法. 该方法只需利用摇摆曲线左腰、右腰和峰位三幅图像, 就能提取出样品的吸收、折射和散射信息, 具有方法简便、样品所受辐射剂量低等优点. 对模型样品和真实样品的实验结果表明, 本文所提方法可成功对样品进行信息分离, 并且所获得的信息分离结果可以和目前常用的多图统计方法(至少需要7张图像)获得的实验结果相比较.
关键词:
衍射增强成像
相位衬度成像
样品信息提取 相似文献
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The influence of interfacial barrier engineering on the resistance switching of In2O3:SnO2/TiO2/In2O3:SnO2 device
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The I-V characteristics of In2O3:SnO2/TiO2/In2O3:SnO2 junctions with different interracial barriers are inves- tigated by comparing experiments. A two-step resistance switching process is found for samples with two interfacial barriers produced by specific thermal treatment on the interfaces. The nonsynchronous occurrence of conducting filament formation through the oxide bulk and the reduction in the interracial barrier due to the migration of oxygen vacancies under the electric field is supposed to explain the two-step resistive switching process. The unique switching properties of the device, based on interracial barrier engineering, could be exploited for novel applications in nonvolatile memory devices. 相似文献
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Ying-Tang Zhang Zi-Yu Chen Chun-Chang Wang Hui-Bin Lü 《Journal of magnetism and magnetic materials》2009,321(9):1199-1201
Polycrystalline perovskite La0.8Tb0.2MnO3 (LTMO) with an orthorhombic phase was synthesized by conventional solid-state reaction. The magnetic and electric properties of La0.8Tb0.2MnO3 were examined. The striking finding is that the material exhibits giant magnetoresistance at room temperature as high as −31.8% and −35.7% under the low magnetic fields of 100 and 1000 Oe, respectively. This result suggests that La0.8Tb0.2MnO3 has a promising potential in future device developments. 相似文献
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采用激光分子束外延技术,在玻璃衬底上制备了La067Sr033MnO3 (LSMO) 薄膜,X射线衍射测量结果表明在玻璃衬底上生长的LSMO薄膜沿c轴择优取向生长.在外磁场3 T和88, 220, 300 K条件下,LSMO薄膜的磁电阻变化率分别达到-378%, -268%和-607%.实验结果表明,在廉价的玻璃衬底上制备大面积和具有应用价值的锰氧化物薄膜是可行的.
关键词:
锰氧化物薄膜
玻璃衬底
外延生长 相似文献
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通过分子动力学(MD)方法研究了不同类型电解质对阴非离子表面活性剂C12EO3C油水界面性能的影响。运用z轴质量密度分布、径向分布函数、分子间相互作用配位数、空间分布函数及均方根位移五种模拟参数来分析电解质与阴非离子表面活性剂的相互作用情况。研究表明,三种离子的加入均对水分子与表面活性剂亲水基形成的水化层结构产生影响,且从微观层面验证三种离子对表面活性剂亲水基相互作用强度大小顺序为Na+ < Ca2+ < Mg2+。通过扩散模拟结果可以较好地解释离子加入对界面张力平衡时间的影响情况。这对指导实验方向、制订最佳复配方案具有重要意义。 相似文献
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By using C-mapping topological current theory and gauge potential decomposition, we discuss the self-dual equation and its solution in the SU(N) Dunne-Jackiw-Pi-Trugenberger model and obtain a new concrete self-dual equation with a δ function. For the SU(3) case, we obtain a new self-duality solution and find the relationship between the soliton solution and topological number which is determined by the Hopf index and Brouwer degree of C-mapping. In our solution, the flux of this soliton is naturally quantized. 相似文献
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