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121.
An efficient new method to synthesize α-oxy N-acyl aminals and hemiaminals in a single step from readily synthesized N-acyl enamines has been developed using PhI(OAc)2 as the oxidant. The reaction conditions are very mild and the products are obtained in good yields (65-92%). A possible mechanistic pathway is laid out. 相似文献
122.
Wang M Wang BM Shi L Tu YQ Fan CA Wang SH Hu XD Zhang SY 《Chemical communications (Cambridge, England)》2005,(44):5580-5582
A quinine/Selectfluor combination inducing rearrangement reaction of allylic alcohols was discovered, which involved a moderate yield with good enantioselective construction of alpha-quaternary carbon center and beta-fluoro aldehyde under base condition. 相似文献
123.
小波变换用于高效液相色谱的基线校正 总被引:26,自引:9,他引:26
本文根据小波变换将信号分频的性质,用Daubechies小波成功地解决了高效液相色谱中基线校正问题,用于定量分析乳酸-稀土络合物体系中的十六个稀土元素,所得结果与仪器给出了结果进行比较,准确度提高,重现性良好。 相似文献
124.
Shan Shan Tang Chang Lu Shao Shou Zhu Li 《中国化学快报》2007,18(4):465-468
Nanofibers of poly(vinyl pyrrolidone) (PVP)/Eu^3+ with diameters of 300-900 nm were prepared by using sol-gel processing and electrospinning technique. The products were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL). The results indicated that, Eu^3+ was successfully embedded in the onedimensional hybrid nanofibers, and the PVP/Eu^3+ hybrid nanofibers had favorable photoluminescence properties. 相似文献
125.
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
126.
The self-assembly of a novel series of donor-acceptor interaction-driven artificial hetero-duplexes in organic media has been described. Four linear compounds 1a-1d, bearing two to five electron rich 1,5-dioxynaphthalene units connected by the tetra(ethylene glycol) linker, respectively, have been prepared and used as donors, while eight compounds 2a-2d, 13-16, bearing one to four electron deficient pyromellitic diimide, 1,4,5,8-naphthalene-tetracarboxydiimide, or perylene-3,4,9,10-tetracarboxydiimide units, respectively, have been used as acceptors. The structure of the hetero-duplexes has been characterized by the 1H NMR, UV-vis spectroscopy and vapor pressure osmometry. It is revealed that the binding stability of the duplexes vary greatly, depending on the length and structure of the monomers and also the solvent, and hetero-duplex 1d·2d displays a maximum association constant of ca. 1.0×104 M−1 in chloroform. 相似文献
127.
Yulu Yang Mingguang Wu Xingwang Zhu Hui Xu Si Ma Yongfeng Zhi Hong Xia Xiaoming Liu Jun Pan Jie-Yinn Tang Siang-Piao Chai Leonardo Palmisano Francesco Parrino Junli Liu Jianzhong Ma Ze-Lin Wang Ling Tan Yu-Fei Zhao Yu-Fei Song Pardeep Singh Pankaj Raizada Deli Jiang Di Li R. A. Geioushy Jizhen Ma Jintao Zhang Song Hu Rongjuan Feng Gang Liu Minghua Liu Zhenhua Li Mingfei Shao Neng Li Jiahe Peng Wee-Jun Ong Nikolay Kornienko Zhenyu Xing Xiujun Fan Jianmin Ma 《中国化学快报》1990,30(12):2065-2088
This roadmap demonstrates a series of two-dimensional nanomaterials, such as graphene, black phosphorus, oxides, layered double hydroxides, chalcogenides, bismuth-based layered compounds, MXenes, metal organic frameworks, covalent organic frameworks, and others, for environmental catalysis. 相似文献
128.
Synthesis and antimicrobial activity of a perfluoroalkyl-containing quaternary ammonium salt 总被引:1,自引:0,他引:1
A novel perfluoroalkyl-containing quaternary ammonium salt 5 was designed and synthesized. Consequently, the antimicrobial activities of compound 5 were measured with Escherichia coli 8099 as a Gram-negative strain and Staphylococcus aureus ATCC 6538 as a Gram-positive strain. Both the minimum inhibitory concentration (MIC, the lowest concentration of compound 5 that inhibits microbial growth) values of quaternary ammonium salt 5 against Escherichia coli 8099 and Staphylococcus aureus ATCC 6538 were 7.8 μg/ml. 相似文献
129.
G. G. Wang J. M. Wang W. Q. Mao H. B. Shao J. Q. Zhang C. N. Cao 《Journal of Solid State Electrochemistry》2005,9(7):524-530
LiMn2O4 powder for lithium-ion batteries was prepared by a precipitation method, and the effects of calcination temperature on the physical properties and electrochemical performance of the samples were investigated by various methods. The results of X-ray diffraction (XRD) showed that the lattice parameter (a) and the unit cell volume (v) decrease with the increasing calcination temperature, and the LiMn2O4 sample calcined at 750°C has smaller particle size and higher crystallinity than other samples. The results of the electrochemical experiments showed that the sample calcined at 750°C has larger peak currents, higher initial capacity, and better cycling capability, because of its lower charge-transfer resistance and larger diffusion coefficient of Li+ ions than those of other samples. 相似文献
130.
Lian HZ Kang YF Bi SP Yasin A Shao DL Chen YJ Dai LM Tian LC 《Analytical and bioanalytical chemistry》2003,376(4):542-548
A reversed-phase high-performance liquid chromatographic method with fluorescence detection for the determination of labile monomeric aluminium has been developed through pre-column complexation using morin as the analytical reagent. The highly fluorescent aluminium-morin complex (excitation wavelength 418 nm, emission wavelength 490 nm) was separated on a Spherisorb ODS 2 column with an eluent consisting of 30% methanol and 70% water (pH 1.0 with perchloric acid). The most remarkable point of this protocol was that only the most toxic aluminium species, that is, free aqua-aluminium ion and its monomeric hydroxo complex ions, selectively respond among various aluminium complexes. This strategy has been successfully applied to direct fractionation of the toxic aluminium in natural waters and biological samples without any pretreatment. 相似文献