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971.
YBCO涂层导体CeO2,Y2O3缓冲层的生长研究 总被引:2,自引:1,他引:2
采用反应溅射的方法在具有立方织构的Ni基底上制备了CeO2,Y2O3缓冲层.Ar/H2气氛下预沉积的引入,有效地抑制了基底的氧化.同时,为保证薄膜的外延取向,预沉积时间必须和总沉积时间满足线性关系.对比CeO2,Y2O3的生长条件,发现CeO2的外延生长区间比Y2O3宽,Y2O3的生长对温度、气压等条件更为敏感.最终制备的CeO2缓冲层是纯的(100)取向,其平面内φ扫描半高宽(FWHM)为8.5°;而Y2O3存在两种平面取向,一种是Y2O3(110)‖Ni(100),另一种是Y2O3(100)‖ Ni(100).俄歇能谱观察表明,CeO2/Ni界面优于Y2O3/Ni界面.扫描电镜照片显示,CeO2,Y2O3缓冲层的表面均匀致密,无裂纹生成,但两种薄膜中,都有呈三角形的胞状突起. 相似文献
972.
973.
974.
两种稀土卟啉配合物与大肠杆菌作用的微量热研究 总被引:5,自引:0,他引:5
用LKB-2277生物活性检测系统测定了新合成的阳离子型稀土卟啉配合物{[Re(TMP)(H2O)3]Cl, Re=Y、Yb, TMP=5, 10, 15, 20-四(4’-甲氧基苯基)卟啉}在37 ℃时对大肠杆菌作用的产热曲线,根据产热曲线求算了在稀土卟啉配合物作用下,大肠杆菌生长代谢的速率常数k,抑制率I,传代时间tG和半抑制浓度cI,50等热动力学参数.结果表明,稀土卟啉配合物在低浓度下对大肠杆菌有刺激作用,高浓度下为抑制作用,[Yb(TMP)(H2O)3]Cl的半抑制浓度cI,50为143 mg•L-1,其对大肠杆菌的抑制作用优于[Y(TMP)(H2O)3]Cl. 相似文献
975.
合成了三种分子中分别含有-S-,-SO-,-SO2-基力的羧酸型离子表面活性剂,并研究了它们的表面活性。 相似文献
976.
977.
Polymerization‐induced self‐assembly of block copolymer through dispersion RAFT polymerization in ionic liquid
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Heng Zhou Chonggao Liu Chengqiang Gao Yaqing Qu Keyu Shi Wangqing Zhang 《Journal of polymer science. Part A, Polymer chemistry》2016,54(11):1517-1525
Polymerization‐induced self‐assembly of block copolymer through dispersion RAFT polymerization has been demonstrated to be a valid method to prepare block copolymer nano‐objects. However, volatile solvents are generally involved in this preparation. Herein, the in situ synthesis of block copolymer nano‐objects of poly(ethylene glycol)‐block‐polystyrene (PEG‐b‐PS) in the ionic liquid of 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIN][PF6]) through the macro‐RAFT agent mediated dispersion polymerization is investigated. It is found that the dispersion RAFT polymerization of styrene in the ionic liquid of [BMIN][PF6] runs faster than that in the alcoholic solvent, and the dispersion RAFT polymerization in the ionic liquid affords good control over the molecular weight and the molecular weight distribution of the PEG‐b‐PS diblock copolymer. The morphology of the in situ synthesized PEG‐b‐PS diblock copolymer nano‐objects, e.g., nanospheres and vesicles, in the ionic liquid is dependent on the polymerization degree of the solvophobic block and the concentration of the fed monomer, which is somewhat similar to those in alcoholic solvent. It is anticipated that the dispersion RAFT polymerization in ionic liquid broads a new way to prepare block copolymer nano‐objects. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1517–1525 相似文献
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979.
Hongyu Zhang Si Li Aihua Qu Changlong Hao Maozhong Sun Liguang Xu Chuanlai Xu Hua Kuang 《Chemical science》2020,11(48):12937
Chiral nanomaterial-based biomimetic catalysts can trigger a similar biological effect to natural catalysts and exhibit high performance in biological applications. Especially, their active center similarity and substrate selectivity promoted their superior biocatalytic activity. Here, modification of critical elements, such as size, morphology, nanocrystal facets, chiral surface and active sites, for controlling the catalytic efficiency of individual chiral nanoparticles (NPs) and chiral nanoassemblies has been demonstrated, which had a synergistic effect on overcoming the defects of pre-existing nanocatalysts. Noticeably, application of external forces (light or magnetism) has resulted in obvious enhancement in biocatalytic efficiency. Chiral nanomaterials served as preferable biomimetic nanocatalysts due to their special structural configuration and chemical constitution advantages. Furthermore, the current challenges and future research directions of the preparation of high-performance bioinspired chiral nanomaterials for biological applications are discussed.Chiral nanomaterial-based biomimetic catalysts can trigger a similar biological effect to natural catalysts and exhibit high performance in biological applications. 相似文献
980.
Elias Bou Maroun Agnès Hagège Christian Basset Eric Quéméneur Claude Vidaud 《Supramolecular chemistry》2013,25(7):585-590
With the aim of developing supports for uranyl cations immobilisation, new 1,3-alternate calix[4]arenes bearing both phosphonic acid functions as chelating sites and N-succinimide-4-oxabutyrate as the anchoring arm were synthesised in good yields. The coupling of such calixarenes to a gel was performed and a successful immobilisation of uranyl cations was obtained. 相似文献