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排序方式: 共有841条查询结果,搜索用时 22 毫秒
41.
Takuji Yamamoto Tomofumi Nishimura Tetsuo Suzuki Hajime Tamon 《Drying Technology》2001,19(7):1319-1333
Resorcinol-formaldehyde hydrogels were synthesized by sol-gel polycondensation of resorcinol with formaldehyde in a slightly basic aqueous solution. RF cryogels, RF xerogels, and RF xerogels (MW gels) were respectively prepared from RF hydrogels by freeze drying, hot air drying, and microwave drying. Carbon cryogels, carbon xerogels and carbon MW gels were subsequently obtained by pyrolyzing RF drygels in an inert atmosphere. Freeze drying and microwave drying were effective to prepare mesoporous RF drygels and carbon gels. RF cryogels and carbon cryogels showed high mesoporosity over wide ranges of the molar ratio of resorcinol to catalyst (R/C) and the ratio of resorcinol to water (R/W) used in sol-gel polycondensation. Although RF xerogels had a few mesopores, carbon xerogels had no mesopores. RF MW gels and carbon MW gels showed mesoporosity if appropriate values of R/C and R/W were selected. 相似文献
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The catalytic activity in the polymerization of styrene has been examined using commercially available simple rare earth metal compounds such as Sm(OiPr)3, Sm(acac)3, Sm(OCOMe)3, SmI2(THF)2 or SmCl3 coupled with Et3Al or methylaluminoxane (MAO). Among these compounds, the Sm(OiPr)3/AlEt3 system shows the highest catalytic activity, especially in the presence of a minor amount of toluene at 60 °C. The random copolymerization of styrene with methyl methacrylate suggests that the present polymerization proceeds with a radical polymerization mechanism. (C5Me5)SmCl3Na(THF) and (C5Me5)SmCl3Li(THF) systems exhibit relatively low catalytic activity, even in the presence of AlEt3. © 2001 Society of Chemical Industry 相似文献
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Annealing Effect in GaDyN on Optical and Magnetic Properties 总被引:1,自引:0,他引:1
Yi-Kai Zhou Masahiro Takahashi Shuichi Emura Shigehiko Hasegawa Hajime Asahi 《Journal of Superconductivity and Novel Magnetism》2010,23(1):103-105
The annealing effect on the optical and magnetic properties of the GaDyN layers was studied. The PL intensities of yellow
and green bands as well as the intra-4f orbital transition of Dy3+ ions were found to decrease for the samples annealed at 900 and 1000 °C. It is supposed that the intra-4f orbital transition is related to the broad peak luminescence coming from defects. Increasing the annealing temperature, the
magnetization becomes smaller. It is considerable that the number of electrons coming from defects was reduced by the annealing
treatments and that the ferromagnetism in GaDyN is attributed as carrier induced ferromagnetism. 相似文献
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Fukano H Tamotsu Z Eiji S Kimitsuna W Teruyuki N 《Journal of Bioscience and Bioengineering》2002,93(1):20-24
Qbeta replicase functioning in Escherichia coli is an RNA-dependent RNA polymerase composed of one phage-coded subunit and three host-coded proteins: ribosomal protein S1, and protein elongation factors EF-Tu and EF-Ts. Qbeta replicase lacking ribosomal protein S1 (alpha-less replicase) is capable of replicating some small RNAs. We attempted to create functional alpha-less replicase by co-expression of the mRNAs that code for the subunits of alpha-less replicase in a rabbit reticulocyte cell-free translation system. Replicase activity, however, could not be detected when both EF-Tu and EF-Ts were co-expressed with the phage-coded subunit. On the other hand, active alpha-less replicase was obtained when an EF-Ts-EF-Tu fusion protein was co-expressed with the phage-coded subunit. Consequently, we succeeded in generating genetically engineered active alpha-less Qbeta replicase which functions in a eukaryotic cell-free system. 相似文献
48.
Hiroshi Kageyama Mitsuhide Miyamoto Hajime Akimoto Shigeyuki Nishitani Toshihiro Sato Toshio Miyazawa 《Journal of the Society for Information Display》2006,14(4):345-351
Abstract— A common‐decoder architecture for a data‐driver circuit fabricated by using a polysilicon process has been developed. The architecture achieves a compact circuit and low‐power consumption. In application to an integrated polysilicon data driver for small‐sized displays, this architecture reduces the area of the data driver by removing the vertical bus lines that occupy a large area. It also suppresses the power consumption of the data bus by reducing the number of driven lines in the data bus during word‐to‐word transitions from six to two. By using a conventional 4‐μm design rule, we fabricated an active‐matrix OLED (AMOLED) panel with an integrated six‐bit data‐driver circuit with 384 outputs. The driver circuit had a height of 2.6 mm and a pitch between output lines of 84 μm. The maximum power consumption of the driver was only 5 mW, i.e., 3.8 mW for logic‐data transfer and 1.2 mW for reference‐voltage source. Furthermore, we also fabricated an active‐matrix LCD (AMLCD) panel including driver circuits of the same type as the integrated elements. Six‐bit full‐color images were successfully displayed on both panels. 相似文献
49.
This letter discusses the problem of designing a feedback compensator that attains the infinite gain margin under the uncertainties of feedback gains. A sufficient condition is given for the existence of compensators and then it is shown that the condition becomes necessary subject to the requirement that the feedback system is decoupled. The nonlinear case is also discussed. 相似文献
50.