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排序方式: 共有1327条查询结果,搜索用时 15 毫秒
991.
Naoki Hayakawa Masato Morikawa Hitoshi Okubo 《Dielectrics and Electrical Insulation, IEEE Transactions on》2007,14(1):39-45
In inverter-fed motor coils, surge voltages with the rise time of several tens or hundreds of nano-second may cause partial discharge (PD) and degradation of electrical insulation performance of the inverter-fed motor coils. This paper discusses PD inception characteristics as well as PD propagation characteristics after PD inception for magnet wire of inverter-fed motor under surge voltage application. Experimental results firstly revealed that PD inception voltage (PDIV) decreased with the increase in the length of enamel-coated wire, which was evaluated in terms of the stressed wire contact length under surge voltage application, i.e. size effect. We proposed a regression line for the size effect on PDIV for the electrical insulation design of inverter-fed motor coils. Secondly, PD propagation characteristics were also investigated under the higher voltage application, and their mechanisms were discussed in terms of generation probability of initial electrons, space charge behavior in the wedge-shaped air gap, charging on the enamel surface and so on 相似文献
992.
Masato Nakajima In-Kil Choi Yasuki Ohtori Young-Sun Choun 《Nuclear Engineering and Design》2007,237(3):277-288
Seismic hazard curves and scenario earthquakes based on probabilistic seismic hazard analysis (PSHA) are evaluated for a site in Korea. Moreover, dominant seismic sources for the site are identified from the contribution factors of the seismic sources. Furthermore, the seismic hazard curves for eight sites in Korea are evaluated to grasp the regional difference of the seismic hazard, and the more detailed information on seismic hazard for Korean sites is obtained. 相似文献
993.
994.
H. Samata M. Kai T. Uchida M. Ohtsuka G. Tanaka S. Sawada T. Taniguchi Y. Nagata 《Journal of Alloys and Compounds》2003,350(1-2):77-85
Crystals of Ba3NaRu2O9−δ (δ≈0.5) and Ba3(Na, R)Ru2O9−δ (R=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb) were grown by an electrochemical method, and their crystallographic, magnetic, and electric properties were studied. All crystals have a hexagonal structure of space group P63mmc. Ba3NaRu2O9−δ and Ba3(Na, R)Ru2O9−δ (except Ce) have a negative asymptotic Curie temperature suggesting the existence of an antiferromagnetic order; however, they are paramagnetic at temperatures above 1.7 K. Ba3NaRu2O9−δ has an effective magnetic moment Peff of 0.91 μB, while Peff of Ba3(Na, R)Ru2O9−δ (except Ce) reflects the large free-ion moment
of the rare earth ions. Ba3(Na, Ce)Ru2O9−δ shows peculiar magnetic behavior that differs from the magnetism of other Ba3(Na, R)Ru2O9−δ crystals. The resistivity of all crystals exhibits an activation-type temperature dependence with an activation energy in the range of 0.10.2 eV. 相似文献
995.
Masato Ito Daigo Setoyama Junji Matsunaga Hiroaki Muta Ken Kurosaki Masayoshi Uno Shinsuke Yamanaka 《Journal of Alloys and Compounds》2006,420(1-2):25-28
Various shapes of flaw-free bulk titanium hydrides (TiHX: X = 1.53–1.75) were fabricated, and its electrical and thermal properties were studied. The electrical conductivity of titanium hydride was slightly lower than that of titanium metal, and it exhibited metal-like temperature dependence. The Seebeck coefficient of the Ti–H system changed from positive to negative due to hydrogenation, and its absolute value for titanium hydride remained at a low magnitude, which is typical for metallic materials. The thermal conductivity of the hydride was the same as that of the metal and increased slightly with increasing temperature. 相似文献
996.
997.
Tanaka K Morimoto Y Toiyama Y Okugawa Y Inoue Y Uchida K Kimura K Mizoguchi A Kusunoki M 《Microscopy research and technique》2012,75(3):307-315
A major challenge of cancer biology is to visualize the dynamics of the metastatic process in secondary organs at high optical resolution in vivo real-time. Here, we presented intravital, dual-colored imaging of liver metastasis formation from a single cancer cell to metastatic colonies in the living liver of living mice using two photon laser scanning microscopy (TPLSM). Red fluorescent protein expressing murine (SL4) or human (HT29) colorectal cancer cell lines were inoculated to the spleen of green fluorescent protein expressing mice. Intravital TPLSM was performed by exteriorizing and fixing the liver lobe of living mice. This was repeated several times for the long-term imaging of the same mouse. Viable cancer cells in the living liver of living mice were visualized intravitally at a magnification of over 600×. Single cancer cells were arrested within hepatic sinusoids 2 h after injection. Platelet aggregation surrounding a cancer cell was observed, indicating a phenomenon of tumor-cell induced platelet aggregation. Cancer cells were extravasated from hepatic sinusoids to the space of Disse. Protrusions of Kupffer cells surrounding a cancer cell were observed, indicating that Kupffer cells appear to phagocytose cancer cells. SL4 cells formed liver metastatic colonies with extensive stromal reaction. Liver metastases by HT29 cells were observed as a cluster of micrometastatic nodules. High-resolution, dual-colored, real-time visualization of cancer metastasis using intravital TLPSM can help to understand spatiotemporal tumor-host interactions during metastatic processes in the living organs of living animals. 相似文献
998.
999.
Engineers and researchers are paying more attention to reinforcement learning (RL) as a key technique for realizing computational intelligence such as adaptive and autonomous decentralized systems. In general, it is not easy to put RL into practical use. In prior research our approach mainly dealt with the problem of designing state and action spaces and we have proposed an adaptive co-construction method of state and action spaces. However, it is more difficult to design state and action spaces in dynamic environments than in static ones. Therefore, it is even more effective to use an adaptive co-construction method of state and action spaces in dynamic environments. In this paper, our approach mainly deals with a problem of adaptation in dynamic environments. First, we classify tasks of dynamic environments and propose a detection method of environmental changes to adapt to dynamic environments. Next, we conducted computational experiments using a so-called “path planning problem” with a slowly changing environment where the aging of the system is assumed. The performances of a conventional RL method and the proposed detection method were confirmed. 相似文献
1000.
The hyperfine-enhanced nuclear moment in TmPO4 was studied by SQUID NMR. A resonance frequency
x
/2 = 274 MHz per tesla was obtained, leading to an enhancement factor of 77.9. The temperature dependence of the spin-lattice relaxation time T
1 of 169Tm nuclear spin in TmPO4 was measured at liquid helium temperatures. The temperature dependence of T
1 can be understood in terms of nuclear Orbach and direct processes. 相似文献