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排序方式: 共有1424条查询结果,搜索用时 15 毫秒
81.
Keisuke Kobayashi Minoru Ryu Yutaka Doshida Youichi Mizuno Clive A. Randall 《Journal of the American Ceramic Society》2013,96(2):531-537
The (1?x)NaNbO3–(x)NaTaO3 solid solution was investigated for x ≤ 0.4 in terms of new high‐temperature and high‐permittivity dielectric system that is suitable for base metal inner electrode capacitor applications. The addition of Ta significantly enhanced the resistivity of the dielectric, resulting in superior resistivity than the dielectrics‐formulated BaTiO3 systems that dominate the multilayer ceramic capacitor dielectric devices. The voltage dependence of the permittivity was also superior to BaTiO3‐based materials, providing higher capacitance at higher temperatures. A transmission electron microscopy study illustrated that the grains had so‐called core‐shell structure. According to the electron diffraction analysis, the core region had an inhomogeneous structure between antiferroelectric and ferroelectric phases, and shell region had an incommensurate ferroelectric‐like structure. The core and shell region had Nb‐ and Ta‐rich composition, respectively, and their interface was compositionally sharp, implying that shell region was formed via a liquid phase during the sintering process with an incongruent Ta dissolution reprecipitation. We anticipate that these or similar materials based on the alkali‐niobate perovskites can be further enhanced to provide capacitor solutions from 150°C to 250°C, which is an important range for a number of new AC–DC invertor and engine control units. 相似文献
82.
Kotohiko Sekoguchi Koji Mori Masuo Kaji Megumi Miwa Masao Nakazatomi Hideo Shimizu 《亚洲传热研究》1996,25(8):568-579
Gas-liquid interfacial profiles in plug flow for both upward and downward flows were obtained using semi-supermultiple point-electrode probes, comprising 67 sensing tips arranged on a tube diameter. Typical interfacial profiles are demonstrated for both flows. Close inspection of the profiles reveals that four zones exist in a pair of gas and liquid slugs for upward plug flow and a high slip velocity region in downward plug flow. The lengths of the swelling liquid front zone and the wake zone were determined. The length of the wake zone strongly depends on the relative velocity between the liquid film around the gas slug and the liquid phase in the liquid slug. Characteristic distributions of bubbles within liquid slugs were found, i.e., three types of radial distributions of void fraction, namely saddle-shaped, trapezoidal and bullet-shaped distributions, exist for upward flow. The two types for downward flow exclude the saddle-shaped distribution. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25 (8): 568–579, 1996 相似文献
83.
Pt electrode dissolution has been investigated using an electrochemical quartz crystal microbalance (EQCM) in H2O2-containing 0.5 mol dm−3 H2SO4. The Pt electrode weight-loss of ca. 0.4 μg cm−2 is observed during nine potential sweeps between 0.01 and 1.36 V vs. RHE. In contrast, the Pt electrode weight-loss is negligible without H2O2 (<0.05 μg cm−2). To support the EQCM results, the weight-decrease amounts of a Pt disk electrode and amounts of Pt dissolved in the solutions were measured after similar successive potential cycles. As a result, these results agreed well with the EQCM results. Furthermore, the H2O2 concentration dependence of the Pt weight-decrease rate was assessed by successive potential steps. These EQCM data indicated that the increase in H2O2 accelerates the Pt dissolution. Based on these results, H2O2 is known to be a major factor contributing to the Pt dissolution. 相似文献
84.
Characterization of alternative plasticizers in poly(vinyl chloride) sheets for blood containers 下载免费PDF全文
Yuji Haishima Tsuyoshi Kawakami Chie Fukui Akito Tanoue Toshiyasu Yuba Satoru Ozono Hidehumi Kumada Kaoru Inoue Tomomi Morikawa Miwa Takahashi Ayano Fujisawa Kayo Yamasaki Yusuke Nomura Kazuo Isama Ung‐il Chung Kumiko Ogawa Shingo Niimi Midori Yoshida 《乙烯基与添加剂工艺杂志》2016,22(4):520-528
This study aimed to optimize the ratio of dioctyl 4‐cyclohexene‐1,2‐dicarboxylate (DOTH) and di‐isononyl‐cyclohexane‐1,2‐dicarboxylate (DINCH®) for use as plasticizers in poly(vinyl chloride) (PVC) sheets. We also evaluated the biological safety of DOTH for its potential to be part of a safe PVC‐based blood container. The suppression of hemolysis in mannitol‐adenine‐phosphate / red cell concentrates (MAP/RCC) with DOTH/(DINCH®‐PVC) sheets and the elution of plasticizers from the sheets increased with higher DOTH compositions. The properties of the PVC sheet containing DOTH and DINCH® in the ratio of 25:33 parts against PVC 100 parts as a weight were almost identical to the PVC sheet made of di(2‐ethylhexyl) phthalate. From a subchronic toxicity test, DOTH did not show any adverse effects on all organs, including the testes, epididymis, liver, and kidneys. The no‐observed‐adverse‐effect level was 300 mg/kg body weight/day in a rat. These results suggest that DOTH/DINCH® (25:33) is a promising candidate for the replacement of di(2‐ethylhexyl) phthalate in blood containers. J. VINYL ADDIT. TECHNOL., 22:520–528, 2016. © 2015 Society of Plastics Engineers 相似文献
85.
The pearlitic transformation and the deformation behavior of lamellar cementite after cold rolling in eutectoid steels Fe-0. 76%C-0. 137%Mn (mass fraction) were studied by means of Formastor-F (Full Automatic Transformation Testing Instrument) and field emission scanning electronic microscopy (FESEM) observation. Fine and coarse pearlite were obtained in the eutectoid steels austenitized at 900℃ for 15min, then hold at 620℃ for 90 s and 690℃ for 7 h, respectively. Thedeformation behavior of cold rolled lamellar cementite could be classified as: cleavage fracture, inhomogeneous slip, fragmentation, thinning or necking, and homogeneous bending. The cementite lamellae with the thickness of more than 100 um could be deformed plastically. 相似文献
86.
Atsunori Nozoe Minoru Abe Keisuke Ohto Hidetaka Kawakita 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(11):1374-1378
BACKGROUND: The formation of polyphenol microspheres by the polymerization of 3‐methylcatechol was performed in a methanol/phosphate buffer solution using horseradish peroxidase (HRP), without the use of a surfactant or a water/oil interface, to be used for germanium recovery. RESULTS: The polyphenol microspheres were of diameter 1 mm. The functional group density of phenol group in the polymer was approximately 15 mol kg?1 determined by the Folin‐Denis method. In batchwise experiments, the amount of germanium adsorbed was 0.23 mol kg?1. CONCLUSION: Because germanium is a rare metal, a system for its recovery is required. Using the proposed system, continuous recovery of germanium can be achieved using multilayered microspheres. Copyright © 2011 Society of Chemical Industry 相似文献
87.
Tomohiro Isogai Kazuhiro Hirooka Tetsuro Tojo Hitoshi Takebayashi Morihiro Saito Minoru Inaba Akimasa Tasaka 《Electrochimica acta》2011,56(12):4425
Metal fluoride added carbon anodes treated by pre-electrolysis were investigated for electrolytic production of nitrogen trifluoride (NF3) in molten NH4F·KF·4HF at 100 °C. The conditions for pre-electrolysis were first optimized using a graphite sheet anode as a model anode. The formation of fluorine-graphite intercalation compounds (fluorine-GICs) with semi-covalent C–F bonds, (CxF)n, on the MgF2 and CaF2 added carbon anode surface was accelerated by pre-electrolysis at potentials less than 4.0 V. Critical current densities (CCD) on the MgF2 added carbon anodes pre-electrolyzed under various conditions were determined, and the highest CCD was 290 mA cm−2 obtained for that pre-electrolyzed at 3.5 V for 500 C cm−2. This anode was successfully used in the electrolysis at 100 mA cm−2 for 290 h and the maximum NF3 current efficiency was 55%. From these results, it was concluded that the metal fluoride added carbon anode treated by pre-electrolysis has a high potential for electrolytic production of NF3 at higher current density. 相似文献
88.
Shigeru Ohshima Yasuto Fujimaki Minoru Takekawa Shoji Fujisawa 《Polycyclic Aromatic Compounds》2013,33(3-4):433-440
To identify nitrobenzanthrones (NBAs) such as 3-nitro-7 H -benz[ de ]anthracene-7-one (3-NBA) on the basis of their electronic spectral data, we have synthesized 1-, 2-, 3-, 9-, and 10-NBAs and measured their absorption and emission spectra. The first strong absorption band of the NBAs appeared in the region 350-440 nm; the band of 10-NBA was red-shifted by about 20 nm. The molar absorptivities of 3- and 9-NBA were about two times as large as those of the others. The fluorescence spectra of the NBAs varied more largely with the position of the nitro group compared to the absorption spectra. The quantum yields of fluorescence were very small, ranging from ~10 m 2 for 2- and 10-NBA to ~10 m 4 for 1- and 3-NBA. 3-NBA exhibited a characteristic spectrum with two broad bands at 450 and 530 nm. On excitation causing an n ~ * transition in the NBAs, their fluorescence intensities increased by a factor of 10. Phosphorescence was observed at 77 K for all compounds though that of 1-NBA was very weak. These results give the promise of characterizing individual isomers of NBAs on the basis of their spectroscopic data. 相似文献
89.
Dr. Tomoya Hirano Dr. Takashi Fujiwara Dr. Hideaki Niwa Michitake Hirano Kasumi Ohira Yusuke Okazaki Shin Sato Dr. Takashi Umehara Dr. Yuki Maemoto Prof. Akihiro Ito Prof. Minoru Yoshida Prof. Hiroyuki Kagechika 《ChemMedChem》2018,13(15):1530-1540
The histone methyltransferase SET7/9 methylates not only histone but also non‐histone proteins as substrates, and therefore, SET7/9 inhibitors are considered candidates for the treatment of diseases. Previously, our group identified cyproheptadine, used clinically as a serotonin receptor antagonist and histamine receptor (H1) antagonist, as a novel scaffold of the SET7/9 inhibitor. In this work, we focused on dibenzosuberene as a substructure of cyproheptadine and synthesized derivatives with various functional groups. Among them, the compound bearing a 2‐hydroxy group showed the most potent activity. On the other hand, a 3‐hydroxy group or another hydrophilic functional group such as acetamide decreased the activity. Structural analysis clarified a rationale for the improved potency only by tightly restricted location and type of the hydrophilic group. In addition, a SET7/9 loop, which was only partially visible in the complex with cyproheptadine, became more clearly visible in the complex with 2‐hydroxycyproheptadine. These results are expected to be helpful for further structure‐based development of SET7/9 inhibitors. 相似文献
90.
Titus Mulembo Gakuji Nagai Hirohisa Tamagawa Takahiro Nitta Minoru Sasaki 《应用聚合物科学杂志》2019,136(44):48167
Conventional conductive materials face challenges when utilizing them for flexible and wearable electronics and soft robotics. Carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites are a promising alternative to the conventional hard conductors because they are light and can realize large deformation. To date, well dispersion of CNTs into PDMS to increase conductivity while maintaining flexibility remains challenging. We aimed at developing highly electrically conductive and flexible multi-walled carbon nanotube/PDMS (MWCNT/PDMS) composites. To this end, we proposed a method to enhance the dispersion of MWCNTs into PDMS using naphthalene and toluene. Our results showed that the addition of naphthalene and toluene into the composites improved dispersion of the MWCNTs and increased the direct current (DC) electrical conductivity. We also found that the morphology of primary aggregates of the MWCNTs influenced the DC electrical conductivity of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48167. 相似文献