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91.
Harumi Yokokawa Natsuko Sakai Tatsuya Kawada Masayuki Dokiy 《Journal of the American Ceramic Society》1990,73(3):649-658
The thermodynamic properties of double oxides in rare earth-transition metal (V and Mn)-oxygen ternary systems have been collected and evaluated to examine their stability using chemical potential diagrams plotted as log (αA /αB ) vs log ( P (O2 )). The thermodynamic regularities of perovskites, pyrochlores, and other compounds have been discussed in terms of the effective ionic radii across a series of rare earths. The obtained regularities have been used to estimate tentatively the thermodynamic properties of some rare-earth vanadium and manganese oxides. 相似文献
92.
93.
The Olympic Games bring tremendous impacts to host cities, yet little attention has been paid to the variety and novelty in urban technologies that are introduced through the mega-event vehicle. This paper argues that urban transformation associated with the Olympic Games increasingly spans the technological sphere. As a path-breaker the Olympic bid of Tokyo foreshadows a technological revolution that will make the capital of Japan the most advanced urban technology metropolis in the world. This is significant, as this pioneer for the city of the future may yield many valuable insights given the rapid implementation and acceleration of technological innovation proceeding into 2020. Consequently, lessons on how this technology may impact our society can be derived. 相似文献
94.
Yulong Zhu Tatsuya Ishikawa Srikrishnan Siva Subramanian Bin Luo 《Soils and Foundations》2021,61(1):198-217
In 2005, the Japanese government launched a new nationwide early warning system for predicting debris flow and slope failure disasters based on rainfall intensity and the Soil Water Index (SWI). However, the Japanese government has not set early warning criteria in many mountain areas. In addition, the existing early warning criteria in some areas are much higher than realistic ones, and snowmelt water is not considered in the calculation of the SWI. These two factors have been the cause of many slope failures in seasonally cold regions, induced by rainfall and/or snowmelt, which were not predicted. Therefore, this study attempts to propose a new determination method for setting early warning criteria for rainfall- and/or snowmelt-induced slope failures in seasonally cold regions. For this purpose, the study firstly proposes a combination model for estimating snow density that incorporates the hourly snowmelt water into the Japanese early warning system more accurately by using meteorological monitoring data and modeled snow density. Next, based on case studies and parametric analyses for slope stability assessment, new early warning criteria are proposed for predicting three different patterns of slope failures under two typical types of precipitation (rainfall and snowmelt) conditions. Finally, a new determination method for setting early warning criteria in seasonally cold regions is proposed by referring to the existing early warning criteria near the target area, in accordance with the precipitation types and the local ground conditions of the slopes. Since the existing early warning criteria near the target area already take the effects of the variations in local geology and geography into account, the new determination method for early warning criteria can be applied to arbitrary areas in seasonally cold regions, without directly considering the local soil properties, in the actual design and maintenance works. 相似文献
95.
Soichi Kugimiya Takeshi Shimoda Jun Tabata Junji Takabayashi 《Journal of chemical ecology》2010,36(6):620-628
Females of the solitary endoparasitoid Cotesia vestalis respond to a blend of volatile organic compounds (VOCs) released from plants infested with larvae of their host, the diamondback
moth (Plutella xylostella), which is an important pest insect of cruciferous plants. We investigated the flight response of female parasitoids to the
cruciferous plant Brassica rapa, using two-choice tests under laboratory conditions. The parasitoids were more attracted to plants that had been infested
for at least 6 hr by the host larvae compared to intact plants, but they did not distinguish between plants infested for only
3 hr and intact plants. Although parasitoids preferred plants 1 and 2 days after herbivory (formerly infested plants) over
intact plants they also preferred plants that had been infested for 24 hr over formerly infested plants. This suggests that
parasitoids can distinguish between the VOC profiles of currently and formerly infested plants. We screened for differences
in VOC emissions among the treatments and found that levels of benzyl cyanide and dimethyl trisulfide significantly decreased
after removal of the host larvae, whereas terpenoids and their related compounds continued to be released at high levels.
Benzyl cyanide and dimethyl trisulfide attracted parasitoids in a dose-dependent manner, whereas the other compounds were
not attractive. These results suggest that nitrile and sulfide compounds temporarily released from plants under attack by
host larvae are potentially more effective attractants for this parasitoid than other VOCs that are continuously released
by host-damaged plants. 相似文献
96.
Takao Morimura Masayuki Hasaka Kunikazu Shimoda Hiromichi Nakashima 《Journal of Electronic Materials》2010,39(9):2149-2153
The thermoelectric half-Heusler compounds Ti
x
NiSn0.998Sb0.002 (x = 1.0 to 1.2) and Ti
y
Zr0.25Hf0.25NiSn0.998Sb0.002 (y = 0.5 to 0.65) with nonstoichiometric nominal compositions were prepared by spin-casting and subsequent annealing at 1073 K
for 24 h. The dimensionless figure of merit ZT at room temperature was maximized at x = 1.1 and y = 0.6 in Ti-rich compounds through an increase in absolute Seebeck coefficients despite a decrease in electrical conductivities.
ZT reached 0.07 at x = 1.1 and 0.14 at y = 0.6. In powder x-ray diffraction analysis, minor phases of β-Sn, TiNi, Ti2Sn, and Ti5Sn3 were observed in addition to a major phase of half-Heusler. The quantity of the minor phases was minimized at x = 1.1 and y = 0.55, where the absolute Seebeck coefficients are maximized. In transmission electron microscopic (TEM) analysis of Ti0.55Zr0.25Hf0.25NiSn0.998Sb0.002, crystal grains of the half-Heusler phase, from several hundred nanometers to several micrometers in size, were observed.
TEM energy-dispersive spectroscopy measurements indicated that fluctuations of Ti, Zr, and Hf compositions within the Ti-site
in the half-Heusler phase may occur. Thermoelectric properties were improved at x = 1.1 and y = 0.6 rather than at the stoichiometric compositions of x = 1.0 and y = 0.5 due to minimization of the precipitate quantities. 相似文献
97.
Kazuya Shimoda Tatsuya Hinoki 《International Journal of Applied Ceramic Technology》2023,20(4):2466-2477
BN-nanoparticle-containing SiC-matrix-based composites comprising SiC fibers and lacking a fiber/matrix interface (SiC/BN + SiC composites) were fabricated by spark plasma sintering (SPS) at 1800°C for 10 min under 50 MPa in Ar. The content of added BN nanoparticles was varied from 0 to 50 vol.%. The mechanical properties of the SiC/BN + SiC composites were investigated thoroughly. The SiC/BN + SiC composites with a BN nanoparticle content of 50 vol.%, which had a bulk density of 2.73 g/cm3 and an open porosity of 5.8%, exhibited quasiductile fracture behavior, as indicated by a short nonlinear region and significantly shorter fiber pullouts owing to the relatively high modulus. The composites also exhibited high strength as well as bending, proportional limit stress, and ultimate tensile strength values of 496 ± 13, 251 ± 30, and 301 MPa ± 56 MPa, respectively, under ambient conditions. The SiC fibers with contents of BN nanoparticles above 30 vol.% were not severely damaged during SPS and adhered to the matrix to form a relatively weak fiber/matrix interface. 相似文献
98.
99.
Yasuda K Nakamoto T Yasuhara M Okada H Nakajima T Kanzaki H Hori M Ozaki H 《Reproduction (Cambridge, England)》2007,133(4):797-806
To assess the role of protein kinase Cbeta (PKCbeta) in human myometrial contractions during pregnancy, we evaluated the effect of a PKCbeta inhibitor (LY333531) on the pregnant and nonpregnant myometrial contractions and compared the level of PKCbeta in the pregnant myometrium with that in the nonpregnant myometrium. The effects of LY333531 on the myometrial contractions were examined by measuring contractile activity (frequency and amplitude). PKCbeta in human myometrium was assessed at mRNA level using real-time PCR method. The characteristics of contractile activity were different between the pregnant and the nonpregnant myometrium. The amplitude of rhythmic contractions in the preterm and term myometrium was increased 2- to 2.5-fold when compared with that in the nonpregnant myometrium, but the frequency of rhythmic contractions was decreased by about half. LY333531 (10(-6) M) reduced the increased amplitude in the preterm and term myometrium by about 50%, and the inhibitory effects of LY333531 in the pregnant myometrium were significantly greater than that in the nonpregnant myometrium (about 50 vs 25%). However, the frequency in the pregnant and nonpregnant myometrium was not influenced by LY333531. Real-time PCR revealed a significant, five- to sevenfold increase in the expression of PKCbeta mRNA in the preterm and term myometrium when compared with the nonpregnant myometrium. These findings suggest that the increased amplitude of human myometrial contractions during pregnancy is related to the increased level of PKCbeta. A PKCbeta inhibitor may reduce preterm uterine contractions and prevent preterm delivery. 相似文献
100.
Chang-Jun Ahn Dongsoo Har Tatsuya Omori Ken-ya Hashimoto 《Digital Signal Processing》2012,22(3):518-525
In a wireless network, the signals transmitted from one sender to different users have independent channel fluctuation characteristics. The diversity that exists between users is called multiuser diversity and can be exploited by the sender to enhance the capacity of wireless network. In multiuser diversity OFDMA system, exploiting channel fluctuation diversity is in essence done by selecting the user with the strong subcarrier channels. The individual subcarrier selection for each user can achieve the best system performance but high signaling overhead and high system complexity are required. On the other hand, the adaptive subcarrier block method achieves worse BER than that of individual subcarrier selection. This is because the selected block contains the poor channel subcarriers. To overcome this problem, in this paper, we propose an adaptive subcarrier block selection with frequency symbol spreading for an OFDMA system. 相似文献