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排序方式: 共有229条查询结果,搜索用时 15 毫秒
91.
S. Ohara Z. Tan J. Noma T. Hanaichi K. Sato H. Abe 《Solid State Communications》2010,150(3-4):198-200
A simple shock event approach inspired by the Allende meteorite to produce sophisticated carbon nanomaterials is reported. It is demonstrated that unique carbon nanostructures, including carbon nanotubes, carbon onions, and new carbon nanorings are synthesized by high-speed ball-milling of steel balls. The carbon nanorings have diameter of several tens of nanometers. It is considered that the carbon nanomaterials are formed from around the surface of steel balls under local high temperatures induced by the collision energy in ball-milling process. 相似文献
92.
We geometrically study the Legendre duality relation that plays an important role in statistical physics with the standard
or generalized entropies. For this purpose, we introduce dualistic structure defined by information geometry, and discuss
concepts arising in generalized thermostatistics, such as relative entropies, escort distributions and modified expectations.
Further, a possible generalization of these concepts in a certain direction is also considered.
Finally, as an application of such a geometric viewpoint, we briefly demonstrate several new results on the behavior of the
solution to a nonlinear diffusion equation called the porous medium equation. 相似文献
93.
TiO2 films were prepared on a silicon or soda-glass substrate using a sol suspension. The TiO2 film on the silicon substrate was composed of pure anatase phase and showed almost no contaminations. In contrast, the TiO2 film on the soda-glass substrate was composed of anatase and brookite phases. The diffusion of Na into the TiO2 film on the soda-glass substrate was observed by XPS, and Na was concentrated on the surface of the film. The yield of the brookite phase increased with decreasing distance from the surface of the film on the soda-glass substrate. Na promoted the formation of the brookite phase, although the preparative procedure was used for anatase synthesis. 相似文献
94.
The adsorptive collection of the molybdenum (VI) complexed with 2-(2-benzothiazolylazo)-p-cresol (BTAC) coupled with the catalytic current of the adsorbed complex at a static mercury drop electrode yields an ultrasensitive voltammetric procedure for the determination of molybdenum. Optimal experimental conditions were: a stirred acetate buffer 0.2 M (pH 3.5) as supporting electrolyte, a BTAC concentration of 1.0 x 10(-6) M as ligand, and a concentration of 0.1 M potassium nitrate as the oxidizing agent. In addition, a preconcentration potential of -0.080 V vs Ag/AgCl (3 M KCl), equilibration time of 15 s, a frequency of 30 Hz, a scan increment of 2 mV, a pulse amplitude of 0.050 mV, and a drop area of 0.032 cm2 were used. The cyclic voltammogram was recorded using a staircase wave with a scan rate of 100 mV/s. The forward scan starts at the initial potential of -0.080 V and is reversed at -0.90 V. Using the catalytic current at approximately -0.55 V the response to the Mo(VI) was found to be linear over a concentration range of 1.0-10.0 microg/L. The limit of detection is as low as 6.2 x 10(-10) M with 4 min of preconcentration time. The possible interference of other trace ions was investigated. The merits of this procedure are demonstrated using of reference samples. 相似文献
95.
A Sawada S Yoshida O Kamiike M Morita M Nishioka T Inomata T Hamada S Ohara Y Ogawa T Maeda 《Radioisotopes》1986,35(9):473-477
During the past 3 years, we have performed 1525 studies of 67Ga scintigraphy and 38 cases of these showed suppressed liver uptake; 19 cases after chemotherapy, 13 cases with liver dysfunction and 6 cases with competitive blockade. Many cases in chemotherapy used cyclophosphamide and vincristine, and were performed 67Ga scan within 1 week after chemotherapy. In cases showed suppressed uptake by liver after chemotherapy, serum Fe was markedly increased and UIBC was markedly decreased (p less than 0.01). This suggested that serum Fe influenced suppressed uptake by liver more than carrier-protein, disturbed hepatic cells, and receptors. 相似文献
96.
An acidic polysaccharide having immunological activities from the rhizome of Cnidium officinale. 总被引:1,自引:0,他引:1
M Tomoda N Ohara R Gonda N Shimizu K Takada Y Satoh S Shirai 《Chemical & pharmaceutical bulletin》1992,40(11):3025-3029
An acidic polysaccharide, designated as cnidirhan AG, was isolated from the rhizomes of Cnidium officinale Makino. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 5.1 x 10(4). It showed pronounced reticuloendothelial system-potentiating activity in a carbon clearance test, and had a remarkable effect on both anti-complementary and alkaline phosphatase-inducing activities. It is composed of L-arabinose: D-galactose: D-glucuronic acid in the molar ratio of 2:6:1, in addition to small amounts of O-acetyl groups. Methylation analysis, carbon-13 nuclear magnetic resonance, controlled Smith degradation and limited acid hydrolysis indicated that the core structural features of cnidirhan AG include a backbone chain composed of beta-1,3-linked D-galactose residues. Some of the galactose units in the backbone carry beta-D-galactosyl side chains at position 6. Both alpha-L-arabinosyl arabinose side chains and terminal beta-D-glucuronic acid residues are linked to the core galactan units. 相似文献
97.
Controlled adsorptive accumulation of copper complexed with TAN, TAC, TAR and TAM (heterocyclic azo-compounds) on a static mercury drop electrode provides the basis for the direct stripping measurement of this element in the nanomolar concentration level. The ligand TAN exhibited great sensitivity and better separation of the peak current of the ligand in relation to the complex. The reduction current of adsorbed complex ions of copper is measured by linear scan cathodic stripping voltammetry, preceded by a period of accumulation of a few minutes. The peak potential is at approximately -0.37 V vs. Ag/AgCl. Optimal experimental parameters were found to be a TAN concentration of 1 x 10(-5)M, an accumulation potential of -0.22 V, and a solution pH of 3.7 (acetate buffer). The detection limit is 0.8nM after a 5-min accumulation with a stirred solution, and the response is linear up to 50 mug/l. Many common cations and anions do not interfere in the determination of copper. The interference of titanium is eliminated by addition of fluoride ion. Results are reported for a fresh water sample. 相似文献
98.
Abstract— Rat liver microsomes treated with heterochromatic visible light (λ > 400 nm) and O2 showed a preferential inactivation of NADPH-cytochrome P450 reductase and cytochrome P450 , proteins involved in drug metabolism. Cytochrome P450 destruction correlates with lipid peroxidation; both are oxygen dependent and affected to the same extent by antioxidants and radical scavengers. Under anaerobic conditions. NADPH-cytochrome P450 reductase is the only component which is inactivated; this is accompanied by FMN loss and activity can be restored by reconstitution. 相似文献
99.
Yoshihisa Kurasawa Ritsuko Katoh Fumiko Mori Minori Fukuchi Megumi Okamoto Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1992,29(4):1009-1011
The reaction of 6-chloro-2-hydrazinoquinoxaline 4-oxide 6 with ethyl 2-(ethoxymethylene)-2-cyanoacetate or (1-ethoxyethylidene)malononitrile gave 2-(5-amino-4-ethoxycarbonylpyrazol-1-yl)-6-chloroquinoxaline 4-oxide 7a or 2-(5-amino-4-cyano-3-methylpyrazol-1-yl)-6-chloroquinoxaline 4-oxide 7b , respectively. The reaction of compound 7a or 7b with dimethyl acetylenedicarboxylate resulted in the 1,3-dipolar cycloaddition reaction and then ring transformation to afford 4-(5-amino-4-ethoxycarbonylpyrazol-1-yl)-8-chloro-1,2,3-trismethoxycarbonylpyrrolo[1,2-α]quinoxaline 8a or 4-(5-amino-4-cyano-3-methylpyrazol-1-yl)-8-chloro-1,2,3-trismethoxycarbonylpyrrolo[1,2-α]quinoxaline 8b , respectively. 相似文献
100.
Electrical and dielectrical properties of poly(bis(-phenoxyethoxy)phosphazene) (I) and its complexes with various content ratios of AgSO3CF3 to monomeric unit (0.25/1 (II) and 0.5/1 (III) in molar ratio) were investigated.Dc conductivity of respective samples at 18 °C were 6.1×10–12, 4.4×10–9, and 7.1×10–8 S/m.Dc conduction was considered to be due to ion hopping. Charge mobility ranged from 3×10–12 to 6× 10–11 m2/Vs depending on the applied field in sample II. In sample I, a tan peak was found which can be ascribed to molecular relaxation of main chains. The peak vanished upon introducing AgSO3 CF3. Temperature dependence of total conductivity (
T
) measured byac method in the temperature range between –150 °C and 50 °C showed several peaks at the temperatures corresponding to the peak temperatures of tan. Total conductivities of respective samples at 100 kHz were 4.9×10–7 (69 °C), 1.7×10–4 (45 °C), and 1.5×10–4(40°C)S/m. 相似文献