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排序方式: 共有1224条查询结果,搜索用时 15 毫秒
141.
142.
Hitoshi Takeda 《Energy and Buildings》1979,2(1):9-17
The energy required to heat and to cool an apartment varies according to the aspect and situations of the rooms in the apartment, the mode of air-conditioning (all day or intermittent) and the geographical location of the building it is situated in. A year-round computer simulation has been carried out using hourly meteorological information throughout 1975 in each of seven districts — Sapporo, Akita, Tokyo, Nagoya, Osaka, Kagoshima and Naha. The capacity requirements of the equipment, and the total energy requirement for year-round air-conditioning for a room situated in the centre of the south side, middle floor of a building in Tokyo was calculated as the planning guide, varying the situations and directions. The research continued with the study of air-conditioning load ratios for each district, measured by the degree-day and calorie-day index, so that year-round air-conditioning loads in other districts could be easily obtained. 相似文献
143.
Effects of the Zn addition to the Cu-Sn matrix of the Nb3Sn composite tape have been investigated by measuring the matrix work-hardening behaviour, the rate of Nb3Sn layer formation and the pertinent superconducting properties. The Zn addition drastically enhances the diffusion rate of Nb3Sn formation at each Sn level in the matrix examined, leading to sufficient superconducting properties even at a low Sn level of 3.5 at. %; a sample containing 3.5 at. % Sn and 15 at. % Zn in the matrix exhibits a critical temperature and critical current density comparable with those of samples at a Sn level of 7 at. %. The upper critical field obtained for a sample with the 6 at. % Cu-6 at. % Sn-4 at. % Zn matrix beyond 200 kOe. The work-hardening of the composite matrix is found to be essentially a function of Sn level, and insensitive to the Zn addition. 相似文献
144.
145.
Cellulose peroxides derived from hydrogen peroxide and cellulose derivative into which a ketone group is introduced by reaction with methyl vinyl ketone were investigated. The amount of peroxide formed on the cellulose substrate increased linearly with increasing carbonyl content of the sample, and sulfuric acid activated the formation of peroxide. The cellulose peroxide was gradually decomposed at 60°C in aqueous medium, and the decomposition was accelerated by addition of ferrous salt or irradiation with light of λ > 300nm. Grafting was initiated by adding methyl methacrylate to the thermal decomposition system under nitrogen. The formation, stability, thermal decomposition, and structure of the cellulose peroxide were discussed in comparison with one derived from aldehyde cellulose and hydrogen peroxide. 相似文献
146.
The activity to initiate graft copolymerization was investigated for various cellulose samples. Oxidation of the sample with hydrogen peroxide or sodium hypochlorite indicated a remarkable increase in the per cent grafting as well as the number of grafts. This phenomenon must be attributed to the formation of special reactive groups in cellulosic materials. However, the treatment with hot water caused a definite decrease in the per cent grafting or the number of grafts for the graft copolymerization on the sample, indicating a lower activity to initiate graft copolymerization. Accordingly, the reactive groups, once formed on the sample by oxidation, seemed to be easily decomposed by hot water. The ferric ion adsorbed on cellulose increased the per cent grafting and accelerated the formation of grafts, and the contribution of metallic ions to the initiation was recognized as one of the important factors of graft copolymerization. 相似文献
147.
148.
Ken Yuki Toshiaki Sato Hitoshi Maruyama Junnosuke Yamauchi Takuji Okaya 《Polymer International》1993,30(4):513-517
Emulsion polymerization of styrene (St) and vinyl acetate (VAc) in the presence of conventional polyvinyl alcohol (PVA), PVA modified with a terminal alkyl group or PVA modified with a terminal thiol group (HS-PVA) was compared. Whereas stable PVAc latexes were obtained, a stable PSt latex was obtained only in the case of HS-PVA. From the adsorption isotherms of these PVAs on the surface of PVAc and PSt latex particles, as well as the grafting efficiencies of VAc and St onto HS-PVA in relation to the stability of the polymerization process, the role of PVA in the emulsion polymerization was discussed. 相似文献
149.
150.
This paper describes the development of three-dimensional electric field analysis by using the so-called segment method which enables the electric field to be calculated with high accuracy and with enhanced efficiency, for high-voltage apparatus. In the segment method, electrode configuration of high-voltage apparatus is simulated by small components which are called segments and by the arrangement of several kinds of such segments. In this calculation, the charge simulation method is used which is suitable for segment application. As basic segments, spherical, cylindrical and ring segments are used and in addition to these, as subsegments, disc and elbow segments are adopted for good simulation of the total electrode configuration. In this paper, the fundamental construction and arrangement parameter of segments were discussed. Moreover, the segment method was applied to an actual high-voltage apparatus and the calculation accuracy was discussed. It was clarified that the segment method has sufficient calculation accuracy and is a very efficient means for three-dimensional electric field analysis. 相似文献