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排序方式: 共有664条查询结果,搜索用时 15 毫秒
111.
1100 kV气体绝缘双断口断路器的开发与产品化 总被引:1,自引:0,他引:1
开发了一种用于气体绝缘组合电器(GIS)的1100kV50kASF6气体双断口断路器(GCB)。研究了这种断路器的各种特性,并成功完成了在绝缘、开断和机械性能等方面的型式试验。实现了GCB的小型化和轻量化。这种新开发的GCB已应用在中国特高压交流示范工程的GIS中,并已于2009年年初投入使用。 相似文献
112.
Bulk glass having a calcium-mica composition (Ca0.5Mg3AlSi3O10F2) is homogeneous glass. The crystallization mechanism of the mica is surface crystallization and transparency is lost completely when crystallization occurs on the surface. In this study, by decreasing SiO2 and increasing CaO and Al2O3 from the chemical composition of Ca0.5Mg3AlSi3O10F2, and moreover by replacing a small amount of K2O instead of CaO, the phase separation appears in the glasses. Because of this phase separation, the mica begins to be crystallized not only on the surface but also in the bulk at lower temperatures. Consequently, the novel transparent machinable mica glass-ceramic can be obtained by heating the glasses having the chemical composition of Ca0.6Mg3Al1.2Si2.8O10F2 and K0.01Ca0.595Mg3Al1.2Si2.8O10F2. As a larger amount of calcium-mica is separated, the bending strength decreases and the fracture toughness increases. Furthermore, by replacing K+ ion instead of Ca2+ ion in the interlayer of calcium-mica, the interlayer bonding strength becomes high, resulting in the increase of the bending strength. 相似文献
113.
Influences of supersaturation in a tetraethyl orthotitanate (TEOT) solution on the degree of crystallinity of product particles in the case of a hydrolysis reaction of TEOT were indicated and the crystallization phenomena of anatase titanium dioxide (TiO2) were discussed. Changes in saturation ratios with experimental durations were examined for the various amount of acetylacetone added into a TEOT solution. At the initial stages of TEOT hydrolysis operations, the degree of crystallinity of product particles was lower for the longer hydrolysis durations but the degrees became almost constant in the later stages of TEOT hydrolysis operations, although the supersaturation of titanium oxide in a TEOT solution was remained. Rapid increase in supersaturation of titanium oxide in a TEOT solution and consequent nucleation of amorphous titanium oxide would be restrained by addition of acetylacetone into a TEOT solution because the concentrations of titanium oxide in a saturated TEOT solution increased with the amount of acetylacetone. 相似文献
114.
Sakai K Nakajima E Takamatsu Y Sharma SC Torigoe K Yoshimura T Esumi K Sakai H Abe M 《Journal of oleo science》2008,57(8):423-429
Adsorption of a cationic gemini surfactant (1,2-bis(dodecyldimethylammonio) ethane dibromide, 12-2-12) and the corresponding monomeric surfactant (dodecyltrimethylammonium bromide, DTAB) on montmorillonite has been characterized with a combination of adsorption isotherm, interlayer spacing and FT-IR spectroscopic data. Adsolubilization of vitamin E into the adsorbed surfactant layers has also been studied. The adsorption isotherm data reveal that the adsorption of the two surfactants is driven by the two factors: one is the cation exchange that occurs on the interlayer basal planes and the other is the hydrophobic interaction between hydrocarbon chains of the surfactants. Although the adsorbed amount measured in the saturation region (in mol g(-1)) is almost identical for the two surfactants, the conformation of the intercalated surfactant molecules differs significantly from each other. The adsorption of DTAB results in a lateral bilayer arrangement in the limited interlayer space, whereas 12-2-12 gives a normal bilayer arrangement in the expanded interlayer space. Adsolubilization of vitamin E takes place into the adsorbed surfactant layers, and interestingly, all the vitamin E molecules added in the montmorillonite suspensions are hybridized at lower surfactant concentrations due to the great specific surface area of the clay material. Since the maximum adsolubilization amount is usually obtained just below the critical micelle concentration, the gemini surfactant is deemed to be more efficient than the corresponding monomeric one to achieve the great adsolubilization amount. 相似文献
115.
Suzuki S Teshima K Lee S Yubuta K Ishizaki T Shishido T Oishi S 《Journal of nanoscience and nanotechnology》2011,11(7):6335-6340
Carbon nanotubes (CNTs) are promising catalyst supports for fuel cell applications. Metal oxide/CNT nanocomposites are also being studied for dye-sensitized solar-cell, photocatalyst, and sensor applications. The fabrication of nanocomposites consisting of highly crystalline NbOx nanotubes and cup-stacked carbon nanotubes (CSCNTs) is reported herein. The CSCNTs were selected for the carbon materials because of their distinctive structure. The CSCNTs were photochemically treated with vacuum ultraviolet light, which increased the amount of oxygen-containing functional groups therein. NbOx nanotubes with no defects were successfully prepared with the chemical treatment of highly crystalline, layered, flux-grown K4Nb6O17 crystals. First, K4Nb6O17 crystals were grown from a KCl flux at a holding temperature of 800 degrees C. Next, NbOx nanosheets were prepared from the layered K4Nb6O17 crystals via a two-step exfoliation process, which consists of proton exchange in an acid solution and intercalation of the tetrabutylammonium ions. The NbOx nanosheets were rolled up into nanotubes with diameters of about 20 nm and lengths of 100-500 nm on the surfaces of the CSCNTs; thus, unique and complex NbOx/CSCNT nanocomposites were successfully fabricated. 相似文献
116.
Tateishi Y Takano I Kobayashi M Tamura Y Tomizawa S Sakai N Kamijo K Nagayama T Kamata K 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(6):319-324
An analytical method for the determination of 32 kinds of pesticide residues in onions, Welsh onions and mushrooms using gas chromatograph with an atomic emission detector (GC-AED) was developed. The pesticides were extracted with acetone-n-hexane (2:3) mixture. The crude extract was partitioned between 5% sodium chloride and ethyl acetate-n-hexane (1:4) mixture. The extract was passed through a Florisil mini-column for cleanup with 10 mL of acetone-n-hexane (1:9) mixture. Although the sensitivity of GC-AED was inferior to that of GC-ECD, GC-AED has a superior element-selectivity. Therefore pesticide residues in foods could be analyzed more exactly by using GC-AED. Thirty-two pesticides including chlorine in onion, Welsh onion and shiitake mushroom were detected without interference. Recoveries of these pesticides from samples determined by GC-AED were 64-114%, except for a few pesticides. 相似文献
117.
Application of microbial genes to recalcitrant biomass utilization and environmental conservation 总被引:3,自引:0,他引:3
Recent papers concerning the application of microbial genes to recalcitrant biomass utilization and environmental conservation are reviewed. Microbial genes have been integrated and expressed in plants and microorganisms. When cellulose-degrading enzyme genes are expressed in rice plants, the transgenic plants exhibit swollen cell walls which increases the digestibility of rice straw in the rumen. When genes encoding aromatic compound-degrading enzymes are expressed in plants, it is expected that aromatic compounds contaminating soil would be degraded during the growth of the transgenic plants. The former transgenic plants are utilized as feed and the latter for phytoremediation. Dockerin and cohesin interactions occurring in the cellulase complex, cellulosome, are applied to the construction of artificial enzyme complexes and protein purification by expressing the genes in transformed bacteria and/or silkworms, respectively. In the case of the forced expression of bacterial genes encoding chitinase and/or hydrogenase in the wild-type bacteria, chitin degradation and hydrogen gas production in the transformed bacteria occur at much higher rates than in the wild type. 相似文献
118.
119.
We report here a simple method to identify the ‘emerging topics’ in life sciences. First, the keywords selected from MeSH
terms on PubMed by filtering the terms based on their increment rate of the appearance, and, then, were sorted into groups
dealing with the same topics by ‘co-word’ analysis. These topics were defined as ‘emerging topics’. The survey of the emerging
keywords with high increment rates of appearance between 1972 to 2006 showed that emerging topics changed dramatically year
by year, and that the major shift of the topics occurred in the late 90s; the topics that cover technical and conceptual aspects
in molecular biology to the more systematic ‘-omics’-related and nanoscience-related aspects. We further investigated trends
in emerging topics within various sub-fields in the life sciences. 相似文献
120.
Limited resources of fossil energy require the search for new energy conversion processes and the increase of the efficiency
of power plants to ensure the energy household in the future. Basically, changing the combustion mode from steady to pulse
combustion makes an enormous reduction of fuel consumption possible. Active control systems for pulse combustors installed
into the inlet further improve the efficiency and extend the operating range considerably. The control algorithm including
fuel rate - air rate - pressure characteristics and control strategies as well are presented. 相似文献