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排序方式: 共有563条查询结果,搜索用时 46 毫秒
41.
A LiMnPO4/C composite cathode was prepared by a combination of spray pyrolysis and wet ball milling. The cathode showed stable performance at various cutoff voltages up to 4.9 V. The cutoff voltage increase up to 4.9 V allowed the achievement of a high discharge capacity in galvanostatic charge–discharge tests. The discharge capacities of 153 mAh g?1 at 0.05 C and 149 mAh g?1 at 0.1 C were achieved at room temperature; the trickle-mode discharge capacities at room temperature were 132, 120 and 91 mAh g?1 at 0.1, 1 and 5 C discharge rates, respectively. The cell exhibited a good rate capability in the galvanostatic cycling up to 5 C discharge rates at both ambient temperature and 50 °C. 相似文献
42.
Tomohiro Narukawa Takayoshi Kuroiwa Izumi Narushima Yasujiro Jimbo Toshihiro Suzuki Koichi Chiba 《Analytical and bioanalytical chemistry》2010,397(2):493-499
Arsenate [As(V)] solution reference material, National Metrology Institute of Japan (NMIJ) certified reference material (CRM)
7912-a, for speciation of arsenic species was developed and certified by NMIJ, the National Institute of Advanced Industrial
Science and Technology. High-purity As2O3 reagent powder was dissolved in 0.8 M HNO3 solution and As(III) was oxidized to As(V) with HNO3 to prepare 100 mg kg-1 of As(V) candidate CRM solution. The solution was bottled in 400 bottles (50 mL each). The concentration of As(V) was determined
by four independent analytical techniques—inductively coupled plasma mass spectrometry, inductively coupled plasma optical
emission spectrometry, graphite furnace atomic absorption spectrometry, and liquid chromatography inductively coupled plasma
mass spectrometry—according to As(V) calibration solutions, which were prepared from the arsenic standard of the Japan Calibration
Service system and whose species was guaranteed to be As(V) by NMIJ. The uncertainties of all the measurements and preparation
procedures were evaluated. The certified value of As(V) in the CRM is (99.53 ± 1.67) mg kg-1 (k = 2). 相似文献
43.
Y.F. Zhang M. Izumi Y.J. Li M. Murakami T. Gao Y.S. Liu P.L. Li 《Physica C: Superconductivity and its Applications》2011,471(21-22):840-842
Single domain superconductor GdBa2Cu3O7?δ bulks with variable additions of (ZnO + ZrO2 + SnO2) nano-particles was prepared in air by using top seed melt-textured growth process. The effect of nano-particle additions on superconductivity properties has been investigated. An enhancement of the critical current JC in low and intermediate field at 77 K and trapped field was discovered by the additions of the nano-particles. At the same time, the superconductor transition temperature, TC, slightly decreases from 93.5 K to 91.5 K. The experimental results show that the accumulation of the nano-particle inclusions may improve JC of the specimens. 相似文献
44.
45.
In the presence of palladium salts, oxidation of 2-nitrostyrenes 1 with nitrous acid alkyl esters 2 resulted in the formation of 2-nitrophenylacetaldehyde dialkyl acetals 3. Reductive cyclization of the acetals 3 with iron powder in acetic acid afforded indoles 5 in good yield. 相似文献
46.
Izumi E Ueda-Nakamura T Dias Filho BP Veiga Júnior VF Nakamura CV 《Natural product reports》2011,28(4):809-823
Here, we review studies that have investigated the activity of plant-derived compounds against Trypanosoma cruzi, the etiologic agent of Chagas’ disease. In the last decade, more than 300 species belonging to almost 100 families have been evaluated for activity, and here we describe the compounds isolated; 85 references are cited. 相似文献
47.
Nakamura Y Inomata S Ebine M Manabe Y Iwakura I Ueda M 《Organic & biomolecular chemistry》2011,9(1):83-85
We report on the design, synthesis and assessment of a novel biaryl-linked (BArL) molecular probe for the exploration of low-abundant target proteins for bioactive compounds based on the activity based protein profiling (ABPP) approach. Surprisingly, the performance of the BArL probe was better than that of the stepwise tagging approach that is considered to be the most effective method used in ABPP study. 相似文献
48.
Sugimoto T Bamba T Izumi Y Nomura H Shiina T Fukusaki E 《Journal of separation science》2011,34(24):3587-3596
This study sought to develop techniques for LC/MS-based metabolomics and to verify that an MS/MS spectral tag (MS2T) could be used in practical secondary metabolite profiling. The retention time (RT), precursor ions, and fragment ions generated by nozzle-skimmer fragmentation were determined using ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOF-MS) and compared with the MS2T. A standard mix was analyzed with UPLC/TOF-MS under the same conditions as were used to construct the MS2T. The difference in RT for the standards was less than 0.15 min and the average RSD was about 2.8%, suggesting that the analysis was highly repeatable. Both precursor ions and fragment ions were observed when the cone voltage was 75 V. Experimental data and fragmentation pattern in the MS2T annotation list were highly similar. Wild-type and cas-1 mutant Arabidopsis thaliana samples treated with an elicitor were analyzed using UPLC/TOF-MS. Sixty-five peaks were successfully annotated. Fragment ions were observed with nozzle-skimmer fragmentation in 50 of 65 (77%) peaks. The reliability of annotation may have increased as a result of fragment ions. Results of multivariate analysis suggested that cas-1 was related to induction of the biosynthesis of these flavonoids. The devised method facilitated practical secondary metabolite profiling. 相似文献
49.
The collision complex formed from a vibrationally excited reactant undergoes redissociation to the reactant, intramolecular vibrational relaxation (randomization of vibrational energy), or chemical reaction to the products. If attractive interaction between the reactants is large, efficient vibrational relaxation in the complex prevents redissociation to the reactants with the initial vibrational energy, and the complex decomposes to the reactants with low vibrational energy or converts to the products. In this paper, we have studied the branching ratios between the intramolecular vibrational relaxation and chemical reaction of an adduct HO(v)-CO formed from OH(X(2)Π(i)) in different vibrational levels v = 0-4 and CO. OH(v = 0-4) generated in a gaseous mixture of O(3)/H(2)/CO/He irradiated at 266 nm was detected with laser-induced fluorescence (LIF) via the A(2)Σ(+)-X(2)Π(i) transition, and H atoms were probed by the two-photon excited LIF technique. From the kinetic analysis of the time-resolved LIF intensities of OH(v) and H, we have found that the intramolecular vibrational relaxation is mainly governed by a single quantum change, HO(v)-CO → HO(v-1)-CO, followed by redissociation to OH(v-1) and CO. With the vibrational quantum number v, chemical process from the adduct to H + CO(2) is accelerated, and vibrational relaxation is decelerated. The countertrend is elucidated by the competition between chemical reaction and vibrational relaxation in the adduct HOCO. 相似文献
50.
The optically active (R)- and (S)-flavanones were prepared by an enzymatically enantioselective hydrolysis of (±)-flavanone oxime O-acylates employing lipases, followed by hydrolysis with acid. 相似文献