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101.
102.
Linkham Douangsavan Vongpaphane Manivong Anan Polthanee Roengsak Katawatin Yoshio Inoue 《山地科学学报》2006,3(3):247-258
Introduction Traditional agriculture based on indigenous knowledge (IK) has been practiced in many areas for centuries. Such practices are often the basis of very sustainable technologies, which are potentially suitable for developmental programs. Polthanee (2001) reported that such farmer practices have been repeatedly found to be valid, rational and usually suited to the local environmental conditions. Moreover, with increased under- standing of agro-ecosystems, professionals in agricultura… 相似文献
103.
104.
H. Inoue 《Experimental Astronomy》1993,4(1):1-10
ASCA (ASTRO-D), the fourth X-ray astronomy satellite of ISAS, was successfully launched on February 20, 1993. It carries nested thin-foil X-ray mirrors providing a large effective area over a wide energy range up to 12 keV. A set of CCD cameras and imaging gas scintillation proportional counters are placed on the focal plane.ASCA is a high-throughput imaging and spectroscopic X-ray observatory with these instruments. 相似文献
105.
Two successive X-ray outbursts of the recurrent X-ray pulsar GX301-2 were observed in April and May, 1982 from Hakucho. Apart from general increase during flares lasting for several days, the X-ray intensity was highly variable on a time-scale of the order of an hour. The outstanding feature is that the amplitude of 700 s pulsation of GX301-2 changes rapidly in a very wide range. When the pulsation is distinct, the depth of modulation is as large as 60%; whereas, the pulse amplitude occasionally diminishes almost to an undetectable level so that the observed X-rays become unpulsed. Such drastic changes are found to occur at any intensity levels observed. In several cases of abrupt changes of pulse amplitude, the intensity at the pulse bottom remained essentially unchanged. These properties suggest a hypothesis that the X-ray emission from GX301-2 consists of a pulsating component with variable amplitude and a non-pulsating component of less variable intensity. 相似文献
106.
Shingo Kosuge Kazuo Aoki Takeshi Inoue David B. Goldstein Philip L. Varghese 《Icarus》2012,221(2):658-669
The behavior of Io’s atmosphere during and after eclipse is investigated on the basis of kinetic theory. The atmosphere is mainly composed of sulfur dioxide (SO2) gas, which condenses to or sublimates from the frost of SO2 on the surface depending on the variation of surface temperature (~90–114 K). The atmosphere may also contain a noncondensable gas, such as sulfur monoxide (SO) or oxygen (O2), as a minor component. In the present study, an accurate numerical analysis for a model Boltzmann equation by a finite-difference method is performed for a one-dimensional atmosphere, and the detailed structure of unsteady gas flows caused by the phase transition of SO2 is clarified. For instance, the following scenario is obtained. The condensation of SO2 on the surface, starting when eclipse begins, gives rise to a downward flow of the atmosphere. The falling atmosphere then bounces upward when colliding with the lower atmosphere but soon falls again. This process of falling and bounce back of the atmosphere repeats during the eclipse, resulting in a temporal oscillation of the macroscopic quantities, such as the velocity and temperature, at a fixed altitude. For a pure SO2 atmosphere, the amplitude of the oscillation is large because of a fast downward flow, but the oscillation decays rapidly. In contrast, for a mixture, the downward flow is slow because the noncondensable gas adjacent to the surface hinders the condensation of SO2. The oscillation in this case is weak but lasts much longer than in the case of pure SO2. The present paper is complementary to the work by Moore et al. (Moore, C.H., Goldstein, D.B., Varghese, P.L., Trafton, L.M., Stewart, B. [2009]. Icarus 201, 585–597) using the direct simulation Monte Carlo (DSMC) method. 相似文献
107.
In the current study, low-background γ-spectrometry was employed to determine the 228Ra/226Ra activity ratio and 137Cs activity of 84 coastal water samples collected at six sites along the main island of Japan (Honshu Island) within the Sea of Japan, including the Tsushima Strait, and two other representative sites on Honshu Island (a Pacific shore and the Tsugaru Strait) at 1-month intervals in 2006.The 228Ra/226Ra ratio of coastal waters in the Sea of Japan exhibited similar patterns of seasonal variation, with minimum values during early summer (228Ra/226Ra = 0.6–0.8), maximum values during autumn (228Ra/226Ra = 1.5–3), and a time lag in their temporal changes ( 2.5 months and over 1300 km distance). However, the 2 other sites represented no clear periodic variation.In contrast to the positive correlation between 137Cs activity (0.6–1.7 mBq/L) and salinity (15–35), the 228Ra/226Ra ratio of coastal water samples from the Sea of Japan was not observed to correlate with salinity, and the increase in the 228Ra/226Ra ratio was not as marked (0.5–1; May–June 2004 and 2005) during the migration along Honshu Island. The input of land-derived water and/or the diffusion of radium from coastal sediments is unlikely to have affected the wide seasonal variation in the 228Ra/226Ra ratio observed in these water samples.The seasonal variation in the 228Ra/226Ra ratio recorded for the coastal waters of the Sea of Japan is considered to be mainly controlled by the remarkable changes in the mixing ratio of the 228Ra-poor Kuroshio and the 228Ra-rich continental shelf waters within the East China Sea (ECS). After passing through the Tsushima Strait, this water mass moves northeast along the coastline of the Sea of Japan as the Tsushima Coastal Branch Current (TCBC). 相似文献
108.
Takahiro Watanabe Toshio Nakamura Fumiko Watanabe Nara Takeshi Kakegawa Kazuho Horiuchi Ryoko Senda Takefumi Oda Mitsugu Nishimura Genki Inoue Matsumoto Takayoshi Kawai 《Quaternary International》2009,205(1-2):12
High-time resolution 14C dating of Lake Baikal sediment cores indicates negative and positive anomalies of calculated linear sedimentation rate (LSR; 1.1 and 35.6 cm/ka, respectively) during the period of climate transition from the last glacial to Holocene. The timing of the Lake Baikal apparent LSR anomalies is consistent with that of the changes in the atmospheric radiocarbon concentration (Δ14C) during Younger Dryas rapid cooling event. 14C dating of lipids in the Lake Baikal surface sediments revealed that the sources of sedimentary lipids were different in each basin. In the Northern Basin of Lake Baikal, the 14C age of total lipids from the surface sediment (4.0 14C ka) was found to be older than that of TOC (1.6 14C ka). By contrast, the 14C age of total lipids in the Southern Basin was younger than that of the TOC by ca. 0.7–3.0 ka.In the Lake Hovsgol sediment cores, ages of the main lithologic boundaries during the last glacial–interglacial transition were estimated based on new 14C data sets. TOC concentration in the cores started to rapidly increase at 13.8 ± 0.3 14C ka at the base of the basinwide finely laminated layer deposited during Bølling/Allerød. The base of the layer diatomaceous mud corresponds to the end of Younger Dryas event (10.6 ± 0.1 14C ka). 相似文献
109.
Yukinori Tani Fumiko Nara Yuko Soma Mitsuyuki Soma Nobuyasu Itoh Genki Inoue Matsumoto Atsushi Tanaka Takayoshi Kawai 《Quaternary International》2009,205(1-2):126
Past changes in phytoplankton assemblages in Lake Baikal over the last 4.5 Ma, both in population and composition, are inferred from the downcore profiles of the relatively stable chlorophyll derivatives steryl esters of pyropheophorbides a and b (steryl chlorine esters; SCEs) in the 0–200 m section of the BDP-98 drill core, supplemented by the data on biogenic silica (BSi) and total organic carbon (TOC) contents. SCEs-a and -b dominate among sedimentary chlorophyll derivatives in the BDP-98 sediments except for the upper few meters, indicating their high stability during diagenetic alteration of sediments. The depth (age) profiles of SCEs-a are consistent with BSi and TOC profiles and are interpreted as reflecting primary productivity of the lake in the past. Baikal proxies reveal close correlation with marine oxygen isotope records (MIS stratigraphy). These observations confirm that climate change in the northern hemisphere has been a primary factor controlling the total phytoplankton productivity in Lake Baikal during the last several million years.Among SCEs-a, C30 (dinostanol)-SCE-a, a marker of dinoflagellates was identified by GC–MS analysis. SCE-b, a marker of green algae, was identified by its UV–vis spectrum. The ratio of C30-SCE-a to total SCEs-a (TSCEs-a) was higher during 4.5–4.2 and 1.7–1.3 Ma, suggesting that dinoflagellates proliferated preferentially in those periods. The early Pleistocene maximum of this ratio corresponds to the broad minimum of diatom abundance previously suggested to have recorded a prolonged regional cooling. An abrupt increase in the SCE-b/TSCEs-a ratio was observed at 2.5–2.6 Ma, indicating that green algae containing chlorophyll b have proliferated in Lake Baikal during this period. This interval has also been suggested to contain evidence for a significant regional cooling based on minima of diatom abundance and BSi in sediments. The depth profile of C27Δ5 (cholesterol)-SCE-a relative to TSCEs-a showed a trend similar to that of BSi, suggesting that C27Δ5-SCE-a/TSCEs-a ratio is a potential marker of diatoms in Lake Baikal.Certain mismatches between the Lake Baikal profiles of biological indicators and the marine oxygen isotope records, as well as the slight temporal offsets between different Lake Baikal biological marker signals suggest that the regional component of climatic and/or lacustrine environmental changes also have played a role in determining the composition of the Lake Baikal Plio-Pleistocene phytoplankton assemblage. 相似文献
110.
Seismological evidence for compositional variations at the base of the mantle transition zone under Japan Islands 总被引:1,自引:1,他引:0
Akira Yamada Dapeng Zhao Toru Inoue Daisuke Suetsugu Masayuki Obayashi 《Gondwana Research》2009,16(3-4):482-490
Temperature and water content anomalies just above the 660-km discontinuity under the Japan Islands are estimated from seismological observations. Two sets of seismological observations of P-wave velocity perturbations and depth variations of the 660-km discontinuity are used, which are (1) long-wavelength (~ 500 km) variations from seismic tomography based on a grid parameterization and waveform analysis of ScS reverberations and (2) moderate-wavelength (~ 150 km) variations from seismic tomography with a block parameterization and receiver-function analysis. To estimate temperature and water content anomalies, partial derivatives of velocity and depth variations with respect to temperature and water content determined by mineral physics studies are used. Under Southwest Japan, low temperature and high water-content anomalies are obtained from both sets of seismological observations, which have already been found by a previous study. Under Northeast Japan, however, there are discrepancies between the results estimated from the two data sets, possibly due to the different resolution scales. This discrepancy is dismissed when examining distributions of the temperature and water content anomalies. These anomalies can be grouped into two geographical locations, one group under Southwest Japan, the other under Northeast Japan. The two groups are clearly separated and exhibit common features in both sets of the seismological observations. The grouping is interpreted by a compositional difference between the subducting Pacific slab under Southwest Japan and a normal mantle under Northeast Japan. 相似文献