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排序方式: 共有165条查询结果,搜索用时 99 毫秒
1.
Nguyen Hoa Hong Joe Sakai Ngo Thu Huong Virginie Brizé 《Journal of magnetism and magnetic materials》2006
Laser-ablated Co-doped In2O3 thin films were fabricated under various growth conditions on R-cut Al2O3 and MgO substrates. All Co:In2O3 films are well-crystallized, single phase, and room temperature ferromagnetic. Co atoms were well substituted for In atoms, and their distribution is greatly uniform over the whole thickness of the films. Films grown at 550 °C showed the largest magnetic moment of about 0.5 μB/Co, while films grown at higher temperatures have magnetic moments of one order smaller. The observed ferromagnetism above room temperature in Co:In2O3 thin films has confirmed that doping few percent of magnetic elements such as Co into In2O3 could result in a promising magnetic material. 相似文献
2.
An application of a new standardization method for rapid activation mass analysis with registration of the strongly absorbed low-energy gamma radiation is described. This method makes it possible to avoid the use of the time-consuming and laborious method of Internal Standard. 相似文献
3.
P.A. Bates E.J. Ditzel M.P. Hartshorn Huong Tuong Ing K.E. Richards W.T. Robinson 《Tetrahedron letters》1981,22(24):2325-2328
Dinitration of 2,4,5-tribromo-3,6-dimethylphenol(1) gives either the tribromodinitro-compound(2) or its acyloin rearrangement product(3), depending on the reaction conditions: X-ray crystal structure analyses are reported for compounds (2) and (3). 相似文献
4.
Journal of Global Optimization - Improperly efficient solutions in the sense of Geoffrion in linear fractional vector optimization problems with unbounded constraint sets are studied systematically... 相似文献
5.
C. Hinnen C. Nguyen Van Huong A. Rousseau J.P. Dalbera 《Journal of Electroanalytical Chemistry》1979,95(2):131-146
The admittance and differential reflectivity of an electrode of polycrystalline gold in contact with aqueous 0.02 M NaF, KClO4, 0.01 M Na2SO4 and KCl have been measured in the range of potential where the electrode is ideally polarized (?0.7 V to 0.8 V NHE). In NaF and KClO4 evidence was obtained for the compression of the adsorbed layer of water. The increase of the number of water molecules, with respect to the number in the least original state (at?4μC cm?2), is 3% at +8 μC cm?2 and at?17 μC cm?2. At the potential of zero charge the water dipoles are oriented preferentially with the oxygen towards the metal. In KCl the optical measurements confirm the existence of two types of Au?Cl? interaction and the covalent character of the bond at the most positive charges. 相似文献
6.
Preparation of Ammonium Rare Earth Halides totally free of Water Ammonium rare earth halides totally free of traces of water were prepared in an one step synthesis from metal, ammonium halide, and halogen in a two step temperature regime. 相似文献
7.
Analysis of organotin compounds by grignard derivatization and gas chromatography-ion trap tandem mass spectrometry 总被引:1,自引:0,他引:1
Tsunoi S Matoba T Shioji H Giang le TH Harino H Tanaka M 《Journal of chromatography. A》2002,962(1-2):197-206
The determination of organotin compounds in water using gas chromatography-tandem mass spectrometry (GC-MS-MS) is described. Several organotin derivatives were synthesized by the reaction of organotin chlorides with Grignard reagents such as methyl-, propyl- and pentylmagnesium halides. After the optimization of the GC-MS-MS conditions, several derivatizations with the Grignard reagents were compared by evaluating the molar responses and volatilities of the derivatives and derivatization yields. As a result, the derivatizing reagent of choice is pentylmagnesium bromide. Calibration curves for the mono-, di- and tributyltins and mono-, di- and triphenyltins with pentylmagnesium bromide were linear in the range of 0.5-100 pg of Sn. The instrumental detection limits of six organotins ranged from 0.20 to 0.35 pg of Sn. The recovery tests from water samples (500 ml) were performed by using sodium diethyldithiocarbamate (DDTC) as a complexing reagent. Except for monophenyltin, the absolute recoveries of organotins from pure water at 200 ng of Sn/l were satisfactory. The recoveries calibrated by surrogate compounds (perdeuterated organotin chlorides) ranged from 71 to 109%. The method detection limits ranged from 0.26 to 0.84 pg of Sn (500-ml sample). This method was applied to the recovery of organotins from river water and seawater. The calibrated recoveries were between 90 and 122%. 相似文献
8.
9.
Quach Thi Thanh Van Le Thi Vien Tran Thi Hong Hanh Phan Thi Thanh Huong Nguyen The Cuong Nguyen Phuong Thao 《Natural product research》2020,34(9):1276-1281
AbstractUsing various chromatographic separations, three new acylated flavonoid glycosides, namely barringosides G–I (1–3), were isolated from the water-soluble extract of Barringtonia racemosa branches and leaves. The structure elucidation was performed by extensive analysis of the 1D and 2D NMR and HR-QTOF-MS data. Of the isolated compounds, barringoside I (3) showed moderate inhibitory effects on LPS-induced NO production in RAW264.7 cells with an IC50 of 52.48?±?1.04?µM. 相似文献
10.
Treatment of molybdenum Fischer carbene complexes with 6-methylene-7-octen-1-yne derivatives at 40 degrees C generates substituted tricyclo[4.3.1.0(1,6)]deca-2,4-dienes in good yield. Pentacarbonyl(butylmethoxycarbene)molybdenum(0) afforded the highest cyclization yields (54%), while the analogous chromium carbene complex gave no reaction. The range of dienyne substrates that participate in this reaction is explored and its mechanism is analyzed and discussed. 相似文献