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排序方式: 共有2075条查询结果,搜索用时 15 毫秒
1.
Ryo Hashikawa Yasuhiro Fujii Atsushi Kinomura Takeshi Saito Arifumi Okada Takashi Wakasugi Kohei Kadono 《Journal of the American Ceramic Society》2019,102(4):1642-1651
Radiophotoluminescence phenomena have been widely investigated on various types of materials for dosimetry applications. We report that an aluminoborosilicate glass containing 0.005 mol% copper exhibits intense photoluminescence in the visible region induced by X-ray and γ-ray irradiation. The luminescence is assigned to the 3d94s1 → 3d10 transition of Cu+. The proportionality of the intensity of the induced photoluminescence to the irradiation dose was confirmed up to 0.5 kGy using 60Co γ-ray irradiation. Based on the spectroscopic results, a potential mechanism was proposed for the enhancement of the photoluminescence. The exposure to the ionizing radiation generates electron-hole pairs in the glass, and the electrons are subsequently captured by the Cu2+ ions, which are converted to Cu+ and emit the luminescence. For the glass containing 0.01 mol% copper, the pronounced enhancement of the photoluminescence was not observed because the reverse reaction, ie, the capture of the holes by the Cu+ ions, becomes prominent. The photoluminescence induced by the irradiation was stably observed for the glasses kept at room temperature and even for the glasses heat-treated at 150°C. However, the induced photoluminescence could be eliminated by the heat treatment at a temperature at 500°C, and the glass returned to the initial pre-irradiation state. The Cu-doped aluminoborosilicate glass is a potential candidate for use in dosimetry applications. 相似文献
2.
Nayve R. Fujii M. Fukugawa A. Takeuchi T. Murata M. Yamada Y. Koyanagi M. 《Journal of microelectromechanical systems》2004,13(5):814-821
This paper describes the fabrication and characterization of a thermal ink jet (TIJ) printhead suitable for high speed and high-quality printing. The printhead has been fabricated by dicing the bonded wafer, which consists of a bubble generating heater plate and a Si channel plate. The Si channel plate consists of an ink chamber and an ink inlet formed by KOH etching, and a nozzle formed by inductively couple plasma reactive ion etching (ICP RIE). The nozzle formed by RIE has squeezed structures, which contribute to high-energy efficiency of drop ejector and, therefore, successful ejection of small ink drop. The nozzle also has a dome-like structure called channel pit, which contributes to high jetting frequency and high-energy efficiency. These two wafers are directly bonded using electrostatic bonding of full-cured polyimide to Si. The adhesive-less bonding provided an ideal shaped small nozzle orifice. Use of the same material (Si substrate) in heater plate and channel plate enables the fabrication of high precision long printhead because no displacement and delamination occur, which are caused by the difference in thermal expansion coefficient between the plates. With these technologies, we have fabricated a 1" long printhead with 832 nozzles having 800 dots per inch (dpi) resolution and a 4 pl. ink drop volume. 相似文献
3.
4.
The breakdown processes of oil films under quasi-static loading have been investigated by using a newly developed steel-oil-mercury system. The relationship between the thickness and breakdown ratio of a hexadecane film is represented by a single master curve independently of the indentation speed, indentation load, and temperature. The master curve shows that the breakdown process of hexadecane includes two stages; one is the decrement of the thickness without breakdown and the other is the decrement of the thickness with a drastic progress of breakdown. By solving a small amount of fatty acid in hexadecane, the thickness increases and the breakdown ratio decreases noticeably; a multilayer residual film supporting normal load is formed between two metal surfaces. Experiments at different temperatures reveal a negative relationship between the temperature and thickness of residual film, which indicates that the residual film is organized by physical interaction rather than chemical interaction. At least under a lower concentration, the residual film appears to consist of not only fatty acid molecules but also hexadecane molecules. 相似文献
5.
K. Fujii J. Fujimoto H. Hayashii R. Kajikawa Y. Masatani H. Ozaki A. Sugiyama R. Suzaki S. Suzuki T.Y. Tsukamoto T.F. Tsukamoto S. Uno S. Iwata 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1985,236(1):55-63
We constructed and tested a prototype gas sampling electromagnetic calorimeter of the Pb-proportional tube sandwich type. The calorimeter uses conductive plastic tubes and cathode pad readout with a tower structure which resulted in reasonable energy and spatial resolutions for electrons in the momentum range 0.5–4.0 GeV/c; /c). This paper describes the test and the performance studied under various conditions. 相似文献
6.
Tatara Takako Fujii Tomiko Kawase Tokuzo Minagawa Motoi 《Journal of the American Oil Chemists' Society》1985,62(6):1053-1058
Journal of the American Oil Chemists' Society - Kinetic parameter of hydrolysis, degree of hydrolysis, pH and temperature characteristics and positional specificity of hydrolysis of seven kinds... 相似文献
7.
H Kuniyasu W Yasui F Shimamoto K Fujii M Nakahara T Asahara K Dohi E Tahara 《Canadian Metallurgical Quarterly》1996,46(12):1005-1010
A rare case of hepatoblastoma in a 61-year-old Japanese housewife is described. This liver tumor mainly consisted of two tissue components: embryonal hepatocytes and primitive mesenchymal tissue. Fetal hepatocytes with alpha-fetoprotein production, gland formation, cartilage and osteoid were also found in a small portion. Molecular analysis by slot blot method revealed increased copy numbers of c-met and K-sam proto-oncogenes and cyclin D1 genes. These findings suggest that alterations of these oncogenes might play a role in the development of adult hepatoblastoma. 相似文献
8.
As a model for organic ferromagnetism in a one-dimensional system, substituted polyacetylenes are re-considered on the basis of the molecular orbital (MO) and the crystal orbital (CO) methods. The semiempirical MO calculations with configuration interaction for the dimer model show that the exchange interaction on poly[(4-oxyphenyl)acetylene] (1) is negative in spite of Ovchinnikov's prediction, due to the direct interaction between the adjacent pendant spins. On the other hand, it is shown that a polyacetylene chain with phenoxy radicals as pendants on every other active site can become a one-dimensional feromagnet. Moreover, the CO calculations by means of the unrestricted Hartree-Fock method give a theoretical background for the realization of a ground state with macroscopic spin alignment on the improved model chain. 相似文献
9.
A new mathematical model for study of an interface crack between two dissimilar elastic half planes is proposed. A process zone is formed along the interface between the physical crack and the continuous part. Both the crack opening (and sliding) displacement with a smooth shape and the finite magnitude of stress concentration appear in this zone. The analytical model is expressed by closed elastic solutions using complex variables, but with no oscillations at the crack tip. 相似文献
10.
Masaru Kadoshima Masahiko HirataniYasuhiro Shimamoto Kazuyoshi ToriiHiroshi Miki Shinichiro KimuraToshihide Nabatame 《Thin solid films》2003,424(2):224-228
We investigated rutile-type titanium dioxide (TiO2) films for possible use as a high-k gate insulator. The TiO2 thin films were directly deposited on Si substrates using a RF magnetron sputtering method with a sintered oxide target. A single phase of rutile-type TiO2 whose dielectric constant of approximately 75 was obtained when the film was deposited in an inert gas atmosphere and annealed at 800 °C in an oxidizing gas atmosphere. The oxygen ions were deficient in the as-deposited film, and consequently, a sufficient oxygen supply was needed to crystallize the film to a single phase of rutile during the post-annealing. However, the interfacial SiO2 layer between the TiO2 and the Si substrate simultaneously grew thicker than 2 nm. As the interfacial SiO2 grew, the leakage current was decreased and the equivalent oxide thickness was increased, in the Au/rutile-type TiO2/Si capacitor. Therefore, we concluded that the growth of the interfacial SiO2 layer thicker than 2 nm is inevitable to form the single phase of rutile-type TiO2 and to decrease the leakage. 相似文献