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排序方式: 共有1398条查询结果,搜索用时 15 毫秒
41.
Akon Higuchi Boo Ok Yoon Takayuki Kaneko Mariko Hara Maya Maekawa Takashi Nohmi 《应用聚合物科学杂志》2004,94(4):1737-1742
We examined the existence of endocrine disruptors in mineral water, ultrapure water, and tap water. GC/MS analysis revealed that dioctylphthalate (di‐n‐octylphthalate and di(2‐ethylhexyl)phthalate) in the water was found to be on the order of parts per billion. The dioctylphthalate concentration remained consistent for mineral water of the same brand, regardless of whether it was bottled in a PET bottle or a glass bottle. Therefore, the dioctylphthalate contamination in mineral water originated from the manufacturing line of the mineral water and not as a result of leaching from PET bottles. Butylated hydroxytoluene (BHT), an oxidization prevention agent in plastics, was detected at 2.05 ± 0.1 ppb in the mineral water bottled in glass bottles, but was not detected in the mineral water bottled in PET bottles. BHT contamination in the mineral water in the glass bottles is likely to have originated from the cap of the glass bottles, as the caps were sealed with polyethylene. We further investigated the feasibility of separating dioctylphthalate and BHT from the mineral water by pervaporation using hydrophobic polydimethylsiloxane membranes. We found that trace amounts (on the order of parts per billion) of organic chemicals such as dioctylphthalate and BHT in aqueous solutions can be removed and concentrated by the pervaporation using polydimethylsiloxane membranes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1737–1742, 2004 相似文献
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Ryosuke Urakami Yukio Sato Masayoshi Ogushi Takeshi Nishiyama Aoi Goto Kazuhiro Yamada Ryo Teranishi Kenji Kaneko Mikito Kitayama 《Journal of the American Ceramic Society》2017,100(3):1231-1240
Microstructure and mechanical property of silicon nitride (Si3N4) ceramic are strongly dependent on the selection of sintering additives. When rare‐earth (RE) oxide is used as the sintering additive, segregation of RE ions at interface between Si3N4 grain and intergranular glassy film (IGF) is believed to play a critical role. Although the ionic radius of RE ion is known to be an empirical parameter to modify the mechanical property, the correlation between the segregated ions and their ionic radii is still under controversy. In order to address this issue, (i) rate of α‐β phase transformation and (ii) segregation behavior at the interface were studied for Si3N4 ceramics sintered using mixture of La2O3 and Lu2O3 as additives in this study. Specimens of Lu content 30% and higher exhibited lower activation energies for the α‐β phase transformation as compared with those of Lu content 20% and lower. In terms of the segregation behavior, La was preferably segregated at one site and Lu at the other site along β‐Si3N4/IGF interface in the specimens of Lu content 30% and higher. It is understood from these results that Lu segregation site should be more closely related with grain growth. 相似文献
45.
Soft sensors are used widely to estimate a process variable which is difficult to measure online. One of the crucial difficulties of soft sensors is that predictive accuracy drops due to changes of state of chemical plants. It is called as the degradation of soft sensor models. In this study, we attempted to classify this degradation of models in terms of changes in an explanatory variable and an objective variable, and the rapidity of the changes. Moreover, we discussed characteristics of adaptive soft sensor models, based on the classification results. By analyzing simulated data sets and a real industrial data set, we could obtain knowledge and information on appropriate adaptive models for each type of the degradation. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2339–2347, 2013 相似文献
46.
Synthesis of rodlike polysiloxane containing polyol moieties derived from glucose with regularly controlled higher-ordered structure 总被引:1,自引:0,他引:1
A rodlike polysiloxane (3) containing polyol moieties derived from the sugar has been synthesized by reaction of an amine-functionalized rodlike polysiloxane (1) with gluconolactone (2) in the presence of triethylamine in DMF. Formation of 3 was estimated by the IR and 1H NMR measurements. The functionality of 2 to the amino groups in 1 was ca. 75%, based on the 1H NMR spectrum of the product. The XRD profile of 3 showed three peaks for a typical hexagonal phase, and the d-value of (100) peak of 3 was larger than that of 1, indicating the regularly controlled higher-ordered structure of 3. 相似文献
47.
J.H. Kaneko T. Tanaka S. Kawamura Y. Oshiki K. Tsuji M. Katagiri K. Ochiai T. Nishitani F. Fujita A. Homma T. Sawamura T. Iida M. Furusaka 《Diamond and Related Materials》2005,14(11-12):2027
Radiation detector was made of a high-quality CVD polycrystalline diamond composed of frost column like structure diamond grains, and induced charge distribution spectra and drift velocities were measured by using alpha particles. As a result, the CVD polycrystalline achieved maximum induced charge of 83% of HP/HT type IIa diamond. Moreover, the CVD crystal had lower charge loss on electrons compared with the HP/HT type IIa diamond. Drift velocities of electrons and holes were ve = 7.7 × 104 and vh = 7.3 × 104cm/s at an electric field of 20 kV/cm, respectively. In addition, response function measurement for 14 MeV neutrons was carried out. 相似文献
48.
Teruya Tanaka Junichi. H. Kaneko Yoshimi Kasugai Masaki Katagiri Hiroshi Takeuchi Takeo Nishitani Toshiyuki Iida 《Diamond and Related Materials》2005,14(11-12):2031
Radiation tolerance of a type IIa synthetic diamond detector was examined from irradiation of mono-energetic 14 MeV neutrons. Measurements of I–V (current–voltage) characteristics and energy spectrum for 5.486 MeV alpha particles were performed after neutron irradiation. In the I–V characteristics measurement, enhancement of rectification was observed after neutron irradiation of up to 2.0 × 1012 n/cm2. Concurrently with the enhancement of rectification, significant decrease in signal amplitude was observed in energy spectrum measurement for alpha particles. It is considered that these changes were due to increase in the concentration of defects acting as shallow energy levels in the forbidden band. For neutron irradiation of higher than 1.6 × 1013 n/cm2, weakening of the rectification characteristics and recovery of the signal amplitude were observed. These changes imply that deep energy levels, which were also considered to be introduced by defects, were dominant and weakened the effects of the shallow energy levels. Increase in the concentration of the deep trapping levels resulted in gradual decrease of the signal amplitude and degradation in the energy resolution. The peak for the alpha particles was obtained up to 5.5 × 1013 n/cm2. 相似文献
49.
Taizo Sano Masamichi Tsuji Nobuyuki Gokon Hiroshi Kaneko Yutaka Tamaura 《Journal of the American Ceramic Society》2000,83(10):2509-2514
Oxygen uptake and release of (Li,Mn) ferrite [LMF; (Li0.60 Mn1.20 Fe1.20 )1−δ O4 ; δ= 0.007 to 0.033] was investigated concerning the relations between redox reactions of ferrite and cation migration. Mössbauer spectroscopy and X-ray diffractometry showed that some of the Li+ and Fe3+ ions migrated from the A sites to the B sites of the spinel-type structure and Mn4+ ions migrated from the B sites to the A sites during oxygen uptake at 573 K. The cation-deficient LMF formed by the oxygen uptake released oxygen molecules in He gas only at 660 K. The cation migration during the oxygen release was in the opposite direction of the movement during oxygen uptake at 573 K. 相似文献
50.
采用有限元软件Deform-3D建立了L形管件三维有限元模型,并对其弯曲过程运动仿真。模拟分析了管件的等效应力、金属流动速度、材料损伤分布以及模具间隙和芯棒对弯管质量的影响。对成形缺陷进行了分析,通过优化得到满足要求的弯曲管件。 相似文献