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排序方式: 共有338条查询结果,搜索用时 787 毫秒
331.
Gen-ichi Konishi Kensuke Naka Yoshiki Chujo 《Journal of Inorganic and Organometallic Polymers》1999,9(3):179-188
Soluble -conjugated coordination polymers having a ruthenium(II) complex in the main chain were prepared from a soluble metal complex monomer and a bridging ligand via coordination. Refluxing of an ethanol-water suspension containing (4,4-dinonyl-2,2-bipyridyl)Ru(III) with 2,3-bis(2-pyridyl)pyrazine gave the coordination polymer. The resulting polymer was soluble in common organic solvents. The structure was confirmed by uv/vis spectra and gpc analysis. 相似文献
332.
We have developed a novel and economical neutral-beam injection system by employing a washer-gun plasma source. It provides a low-cost and maintenance-free ion beam, thus eliminating the need for the filaments and water-cooling systems employed conventionally. In our primary experiments, the washer gun produced a source plasma with an electron temperature of approximately 5 eV and an electron density of 5 × 10(17) m(-3), i.e., conditions suitable for ion-beam extraction. The dependence of the extracted beam current on the acceleration voltage is consistent with space-charge current limitation, because the observed current density is almost proportional to the 3∕2 power of the acceleration voltage below approximately 8 kV. By optimizing plasma formation, we successfully achieved beam extraction of up to 40 A at 15 kV and a pulse length in excess of 0.25 ms. Its low-voltage and high-current pulsed-beam properties enable us to apply this high-power neutral beam injection into a high-beta compact torus plasma characterized by a low magnetic field. 相似文献
333.
In situ extractive fermentation of lactic acid using organic solvents has already been extensively investigated. Now ionic liquids are emerging as alternative solvents for volatile organic compounds traditionally used in liquid-liquid extraction. In this study, we examine whether lactic acid producing-bacteria can grow in the presence of a second phase of imidazolium-based ionic liquids or organic solvents. The lactic acid producing-bacteria used in this study are sensitive to organic solvents having 1 < log P < 4. We found that Lactobacillus delbruekii subsp. lactis NRIC 1683 could grow in the presence of a second phase of imidazolium-based ionic liquids as well as in the absence of the ionic liquids. 相似文献
334.
Ono K Ban N Ojima M Yoshinaga S Akahane K Fujii K Toyota M Hamada F Kouriyama C Akiba S Kunugita N Shimada Y Kai M 《Radiation protection dosimetry》2011,146(1-3):260-262
A nationwide survey was conducted in Japan on paediatric CT among children of public health and school nurses to examine a possibility for a follow-up study on radiation effects. A survey questionnaire was sent out to 3173 public primary and junior high schools and 317 public health centres during October to December in 2009. According to the collected responses, 410 (16.2 %) children received the CT scans and the total number of CT scans was 585. Most of respondents expressed a high interest in radiation health effects and an intent to participate in the epidemiological study that will follow-up the health conditions of children. This study provides information to discuss the feasibility of the epidemiological study on health effects in children who received CT scans. 相似文献
335.
Preparation of composites of liquid‐crystalline matrix of poly(p‐phenylene‐sulfoterephthalamide) and CaCO3 by In situ mineralization
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Liquid‐crystalline (LC) hydrogels were obtained from an aqueous solution of poly(p‐phenylene‐sulfoterephthalamide) (PPST) by the addition of calcium ions (Ca2+). The critical hydrogel formation ratio of Ca2+ to the sulfonic acid group in PPST (crtRCa = [Ca2+]/[ ]) depended on the concentration of PPST, and was independent of the molecular weight of PPST. When the LC hydrogel was prepared at a concentration of 0.5 wt % and crtRCa = 0.6, and was exposed to ammonium carbonate vapor for 96 h, all Ca2+ in the LC hydrogel were converted into calcite crystals. The alternate soaking process for the LC hydrogel induced the formation of two mesocrystal morphologies on and in the Ca2+ cross‐linked LC hydrogel. Plate‐like calcite mesocrystals grew at the hydrogel/solution interface and cubic mesocrystals were present in the inner space of the hydrogel, thus composites with some ordered structures of LC matrix and CaCO3 have been prepared through in situ mineralization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41455. 相似文献
336.
Shiro Takahashi Akinori Tamura Shunichi Sato Toshitaka Goto Michiaki Kurosaki Noriyuki Takamura 《Journal of Nuclear Science and Technology》2016,53(8):1164-1177
Some problems due to flow-induced vibrations related to closed side branch pipes have been observed in thermal and nuclear power plants. Fluctuating pressure generated in the main pipes was unusually, acoustically excited in closed side branch pipes, and intense vibrations were caused at pipes and components. For example, flow-excited acoustic resonance in closed side branches of stub pipes of safety relief valves caused the failure of steam dryers in the United States Quad City Unit 2 nuclear power plant. Furthermore, there was a possibility that residual air or gas in a closed side branch pipe unexpectedly caused severe vibrations of low frequency in the feed water piping system. We have investigated the root cause and influence of air on severe vibrations. Intense fluctuating pressure was often caused by water hammer due to valve closure and it became larger in the closed side branch pipes. We showed that an additional side branch with an orifice was very effective to suppress the flow-induced acoustic resonance. Design methods of the orifice to attenuate fluctuating pressure generated by water hammer were presented considering Mach number, the pressure loss coefficient of orifice and the intensity of particle velocity. Moreover, suitability of the characteristic curve method was confirmed for evaluation of the attenuation effect of an orifice on fluctuating pressure generated by water hammer. Finally, we considered some flow-induced vibration problems related to closed side branch pipes and their attenuation methods. 相似文献
337.
Takayuki Nakane Satoshi Ishii Tetsuo Uchikoshi Takashi Naka 《Journal of the American Ceramic Society》2023,106(4):2317-2325
We report a systematic evaluation of the magnetic properties of FeAl2O4 focusing on the relationship between the fabrication conditions and its structural characteristics, in order to improve ceramics processing in applications of this material. For this purpose, the most important factor to control is the inversion parameter, expressed as y in the (Fe1−yAly)(Al1−y/2Fey/2)2O4 composition, which is relatively high for the spinel aluminate of a transition metal. The magnetic properties of these samples all show the spin glass phenomenon at low temperatures, and the cusp temperature depends systematically on this y value. This means that the evaluation of these magnetic properties will be an effective way to predict some characteristics of product FeAl2O4. Additionally, this study found an anomaly in the structural and magnetic characteristics of FeAl2O4 fabricated at a low temperature. This is thought to originate in a tiny and a small amount of impurity. It will be key for discussing the quality of chemically synthesized FeAl2O4, which is typically produced at low temperatures. 相似文献
338.
Risa Naka Prof. Kousuke Tsuchiya Prof. Keiji Numata 《Chembiochem : a European journal of chemical biology》2023,24(12):e202200803
Zwitterionic molecules, such as zwitterionic liquids (ZILs) and polypeptides (ZIPs), are attracting attention for application in new methods that can be used to loosen tight cell wall networks in a biocompatible manner. These novel methods can enhance the cell wall permeability of nanocarriers and increase their transfection efficiency into targeted subcellular organelles in plants. Herein, we provide an overview of the recent progress and future perspectives of such molecules that function as boosters for cell wall-penetrating nanocarriers. 相似文献