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91.
Mohammad Nurunnabi Baitao Li Kimio Kunimori Kimihito Suzuki Ken-ichiro Fujimoto Keiichi Tomishige 《Catalysis Letters》2005,103(3-4):277-281
The addition of Pt on NiO–MgO solid solution enhanced the performance of oxidative steam reforming of methane, especially, the catalyst can be activated during the oxidative reforming of methane at low reaction temperature like 823 K. 0.1% Pt/Ni0.2Mg0.8O exhibited much higher performance than 0.1% Pt/MgO and Ni0.2Mg0.8O. From the comparisons, the additive effect of Pt to Ni0.2Mg0.8O is to promote both the activity of combustion and reforming of methane. This additive effect can be explained by the high combustion activity caused by the synergy of Pt with NiO–MgO solid solution and the high catalyst reducibility. 相似文献
92.
Natural denitrification in the Kakamigahara groundwater basin,Gifu prefecture,central Japan 总被引:2,自引:0,他引:2
Mohamed MA Terao H Suzuki R Babiker IS Ohta K Kaori K Kato K 《The Science of the total environment》2003,307(1-3):191-201
Although nitrate is recognized as the most common groundwater contaminant due to growing anthropogenic sources, such as agriculture in particular, its adverse effects on human and animal health are debatable. The current issue, however, is to control and reduce nitrate contamination with regards to the long residence time of groundwater within aquifers. Denitrification has recently been recognized for its ability to reduce high nitrate concentrations in groundwater. The Kakamigahara groundwater basin, Gifu prefecture, Japan, witnessed rising levels of nitrate (>12 mg/l NO(3)-N) originating from agricultural sources. Chemical analyses for the determination of major constituents of groundwater and delta(15)N of residual nitrate were performed on representative groundwater samples in order to fulfill two main objectives. One is to investigate the current situation of nitrate groundwater pollution. The second objective is to determine whether the denitrification is a potential natural mechanism, which eliminates nitrate pollution in the Kakamigahara aquifer. Agricultural nitrate contamination of groundwater was obvious from characteristically high concentrations of Ca(2+), Mg(2+), NO(3)(-) and SO(4)(2-). High nitrate concentrations were found on the eastern side of the basin in association with vegetable cultivation fields, and decreased gradually towards the west of the basin along the direction of groundwater flow. The decrease of nitrate concentration was conveniently coupled with increase of HCO(3)(-) (the heterotrophic denitrification product), pH and delta(15)N of residual nitrate (due to isotopic fractionation) from east to west. Therefore, denitrification in situ is continuously removing nitrate from the Kakamigahara groundwater system. 相似文献
93.
Takanori Kobayashi Keiichi Yokoyama 《Journal of Nuclear Science and Technology》2016,53(10):1489-1493
Theoretical investigation for the adsorption of the cesium atom (Cs), the cesium iodide molecule (CsI), the iodine atom (I), the cesium cation (Cs+), and the iodide anion (I?) onto the surface of a single fullerene molecule (C60) are reported. A hybrid exchange–correlation functional using the Coulomb-attenuating method (CAM-B3LYP) is employed. The adsorption energies, i.e., the opposite of enthalpy change through adsorption, are calculated to be 143, 12, 9, 46, and 49 kJ mol?1 for Cs, CsI, I, Cs+, and I?, respectively. The equilibrium constant for Cs is calculated to be 7×103 atm?1 at the temperature of 1000 K and is seven orders of magnitude higher than that for CsI, indicating that the C60 molecule adsorb the Cs atom highly selectively against the CsI molecule. 相似文献
94.
Nakagawa K Yoda K Masutani Y Sasaki K Ohtomo K 《IEEE transactions on bio-medical engineering》2007,54(5):943-946
A compensator made of a tungsten-based rod matrix has been proposed for small-field intensity modulated radiation therapy. The compensator was attached to a 6 MV linac gantry head. The proposed compensator could modulate the X-ray intensity with a step of 10% and a minimum transmission of 2.5%. 相似文献
95.
Nakagawa K Yoda K Shiraki T Sasaki K Miyazawa M Ishidoya T Ohtomo K Hamada M 《Radiation protection dosimetry》2007,123(2):254-256
A radiophotoluminescence dosimetry has been proposed using a spherical silver-activated phosphate glass with a diameter of 1.5 mm. A 6 MV photon dose of 2 Sv (2 Gy) was delivered to 14 spherical glass samples placed between two solid water phantoms at a depth of 10 cm. The samples were positioned within a 20 x 20 mm(2) centred at beam axis to ensure uniform dose absorption. A normalised output from a read-out system was obtained by simultaneously measuring luminescence from a non-irradiated reference and that from an irradiated reference to eliminate background contamination and time-varying fluctuation of the readout system, leading to a normalised standard deviation of 1.8%. A dose up to 3.5 Sv (3.5 Gy) was delivered to three spherical glass samples positioned between two solid water phantoms at a depth of 10 cm. The normalised output increased linearly with the applied dose. 相似文献
96.
Uchino K Katsumata Y Takeda T Arai H Shiraki M Saito T 《Journal of Bioscience and Bioengineering》2007,104(3):224-226
An intracellular 3-hydroxybutyrate-oligomer hydrolase was purified from a poly(3-hydroxybutyrate)-degrading bacterium, Paucimonas lemoignei. It hydrolyzed the 3-hydroxybutyrate dimer with the highest specific activity of any of the enzymes reported so far. The gene was cloned and sequenced. The deduced amino acid sequence showed that the enzyme is a homolog of the PhaZc of Ralstonia eutropha H16. 相似文献
97.
Mikihiro Yoshie Kazuya Kusama Risaka Tanaka Takanori Okubo Junya Kojima Yotaro Takaesu Keiichi Isaka Hirotaka Nishi Kazuhiro Tamura 《International journal of molecular sciences》2021,22(19)
Previous in vitro studies have suggested that calreticulin (CALR), which is responsible for the folding and quality control of glycoproteins, may be associated with decidualization. However, its precise role in regulating decidualization has not been explored in vivo. Here, we used pregnant rat models to examine endometrial CALR expression during the peri-implantation period. We also examined whether polypectomy, a procedure that could ameliorate infertility, alters the endometrial expression levels of CALR and several implantation factors in women diagnosed as infertile. In rats, uterine CALR was expressed at a high level at the implantation site, and a marked increase in CALR expression was observed in decidual cells of normal pregnancy. In addition, endometrial CALR expression was enhanced by either administration of estradiol-17β in the delayed implantation rat model or the artificial induction of decidualization in the pseudopregnant rat. In cultured stromal cells, siRNA-mediated silencing of CALR inhibited the decidual stimulus-induced expression of prolactin, decidual/trophoblast prolactin-related protein, and connexin 43. In humans, the endometrial expression levels of the mRNAs encoding CALR and the implantation-related factor insulin-like growth factor binding protein (IGFBP)-7 tended to increase after polypectomy. The strongest positive correlation between expression levels before polypectomy was observed for IGFBP-7 and CALR, and the strength of this correlation increased after the surgery. Thus, endometrial CALR may play a role in the formation of decidua, and the polypectomy of infertile patients may result in the co-operative expression of endometrial factors, including CALR, that could enhance endometrial receptivity. 相似文献
98.
An ultrafast X‐ray computed tomography (CT) scanner has been developed. This scanner overcomes problems that occur in a transient or unsettled state, which make the conventional CT scanner inappropriate. To reduce the scanning time, this X‐ray CT system uses electronic switching of electron beams for X‐ray generation instead of the mechanical motion adopted by conventional CT scanners. The mechanical motion is a major obstacle to improving scanning speed. A prototype system with a scanning time of 3.6 ms was initially developed and confirmed to measure the dynamic events of two‐phase flow. However, an increased scanning speed is generally required for practical use in the thermal hydraulics research field. Therefore, an advanced type which can operate under the scanning time of 0.5 ms and can measure two‐phase flow with a velocity up to 4 to 5 m/s was developed. © 2000 Scripta Technica, Heat Trans Asian Res, 29(3): 155–165, 2000 相似文献
99.
K. Yamagata Fumi Okabe Motoyoshi Yamazaki 《Advanced Synthesis \u0026amp; Catalysis》2000,342(5):494-497
4‐Amino‐2,5‐dihydro‐3‐thiophenecarbonitriles 1 reacted with dimethyl diazomalonate in the presence of rhodium(II) acetate to give regioselectively 4‐cyano‐2H‐thio‐pyrans 2 (C 2— S insertion), and 5‐cyano‐2H‐thiopyrans (C 5— S insertion) were not isolated. Similar insertion was also observed in the reaction of 1 with methyl diazoacetoacetate and ethyl diazobenzoylacetate. The starting compounds 1 were synthesized by the reaction of tetrahydro‐4‐oxo‐3‐thiophene‐carbonitrile with morpholine, piperidine, and pyrrolidine in the presence of formic acid in ethanol. 相似文献
100.
This paper presents the results of an investigation on the loop current of a thyristor-controlled series capacitor (TCSC). The knowledge of loop current characteristics is important for understanding analytically the equivalent impedance of TCSC, estimating harmonics produced by TCSC, and determining ratings of the TCSC circuit components. However, little has been written on the loop current of TCSC circuit. Therefore, using a laboratory-scale TCSC installed on a laboratory power system, the TCSC currents and voltages were measured and analyzed to investigate the behavior of loop current. A mathematical model of TCSC was also developed to compare to the experimental results and further clarify the relationship between loop current and steady-state impedance characteristics, including effects of TCSC circuit component size on the characteristics. Capacitor voltage harmonics and their impact on the power system were also investigated. ©1998 Scripta Technica, Electr Eng Jpn, 125(1): 37–46, 1998 相似文献