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Y. Kashiwagi 《Theoretical and Applied Climatology》1991,43(4):205-209
Summary The geographical distribution ofPinus densiflora forests in Japan was examined in relation to the seed germination and seedling establishment information obtained from laboratory experiments, field observations and field experiments. The laboratory experiments indicated that seed germination can occur in all areas of Japan because effective cumulative soil temperatures reaches to 75 °C · day everywhere. However, the field observations and field experiments suggested that seedling establishment is impossible in the northern, eastern and central parts of Hokkaido because the effective cumulative air temperature at a height of 6 cm over bare ground is less than 2 000 °C · day. These results agree approximately with the actual geographical distribution ofP. densiflora forest, which can not be found under natural circumstances in these areas.With 3 Figures 相似文献
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Sato T. Suzuki Y. Kashiwagi H. Nanjo M. Kakui Y. 《Oceanic Engineering, IEEE Journal of》1978,3(1):1-4
A laser method for the remote detection of oil present as a pollutant in the sea water using Raman backscattering and backscattered fluorescence is discussed. The scattering spectra of oils obtained by using a laser Raman spectrometer that employs a CW Ar laser are described. The backscattering spectra of oils obtained by a laser radar technique in the laboratory and the field are also described. Furthermore, theoretical performance of a laser radar with a CW laser or a pulsed laser for the detection of Raman backscattering of kerosene is discussed. 相似文献
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Y. Kashiwagi 《Theoretical and Applied Climatology》1991,43(3):149-158
Summary The succession mechanism from stands ofMiscanthus sinensis to stands ofPinus densiflora was studied in relation to elements of microclimates within those plant communities. Laboratory experiments indicated that the seed germination ofP. densiflora occurred at cumulative soil temperature between 75 °C day and 200 °C day. It is assumed from field research that establishment ofP. densiflora seedlings is impossible if the effective cumulative air temperature at a height of 6 cm is less than 2,000 °C day, and the cumulative solar radiation figure totals less than 633 MJ/m2. The seedlings thrived in aM. sinensis stand growing on gently convex topography, which fulfills the requisites mentioned above. The seedlings in aM. sinensis stand growing on gently concave topography and in aP. densiflora stand died completely by October.With 4 Figures 相似文献
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Toshiyuki Kurihara Kazuhiro Tsukada Shigeru Otoh Kenji Kashiwagi Minjin Chuluun Dorjsuren Byambadash Bujinlkham Boijir Sersmaa Gonchigdorj Manchuk Nuramkhan Masakazu Niwa Tetsuya Tokiwa Gen’ya Hikichi Takafumi Kozuka 《Journal of Asian Earth Sciences》2009,34(2):209-225
Recent mapping projects undertaken in Central Mongolia have revealed the widespread occurrence of radiolarian chert within a Paleozoic accretionary complex. We present the results of the first detailed tectonostratigraphic and radiolarian biostratigraphic investigations of the Gorkhi Formation in the Khangai–Khentei belt of the Central Asian Orogenic Belt.The Gorkhi Formation consists of sandstone shale, alternating sandstone and shale of turbidite affinity and chert with small amounts of siliceous shale, basalt, limestone, and clast-bearing mudstone. Radiolarian chert that is completely devoid of terrigenous clastic material is commonly associated with underlying basalt (sedimentary contact) and with conformably overlying siliceous shale and turbidite deposits. The tectonic stacking of basalt–chert and chert–turbidite successions is the most remarkable structural feature of the formation.The recovery of moderately well-preserved radiolarians and conodonts from red chert led to the recognition of four radiolarian assemblages that have a combined age range from the latest Silurian (Pridolian) to the Late Devonian (Frasnian). No age control exists for the siliceous shale, shale, and sandstone, although they are considered to be latest Devonian or slightly younger on the basis of stratigraphic relationships with underlying chert.The Gorkhi Formation has previously been interpreted as a thick sedimentary basin deposit overlying an unexposed Archean–Neoproterozoic basement; however, the stratigraphy within individual tectonic slices clearly corresponds to that of an ocean plate stratigraphy of an accretionary complex generated by the trenchward movement of an oceanic plate. From the lowermost to uppermost units, the stratigraphy comprises ocean floor basalt, pelagic deep-water radiolarian chert, hemipelagic siliceous shale, and terrigenous turbidite deposits. The biostratigraphic data obtained in the present study provide corroborating evidence for the existence of an extensive deep-water ocean that enabled the continuous sedimentation of pelagic chert over a period of nearly 50 million years. These data, together with structural data characterized by tectonic repetition of the stratigraphy, indicate that these rocks formed as an accretionary wedge along an active continental margin, possibly that of the Angara Craton. The mid-oceanic chert was probably deposited in the Northern Hemisphere portion of the Paleo–Pacific Ocean that faced the Angara Craton and the North China–Tarim blocks. Thus, we propose that subduction–accretion processes along the Paleo–Pacific rim played an important role in the accretionary growth of the active continental margin of the Angara Craton, directly influencing the evolution of the Central Asian Orogenic Belt. 相似文献
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T. Shimizu S. Nagata S. Tsuneta T. Tarbell C. Edwards R. Shine C. Hoffmann E. Thomas S. Sour R. Rehse O. Ito Y. Kashiwagi M. Tabata K. Kodeki M. Nagase K. Matsuzaki K. Kobayashi K. Ichimoto Y. Suematsu 《Solar physics》2008,249(2):221-232
The Hinode Solar Optical Telescope (SOT) is the first space-borne visible-light telescope that enables us to observe magnetic-field
dynamics in the solar lower atmosphere with 0.2 – 0.3 arcsec spatial resolution under extremely stable (seeing-free) conditions.
To achieve precise measurements of the polarization with diffraction-limited images, stable pointing of the telescope (<0.09 arcsec,
3σ) is required for solar images exposed on the focal plane CCD detectors. SOT has an image stabilization system that uses image
displacements calculated from correlation tracking of solar granules to control a piezo-driven tip-tilt mirror. The system
minimizes the motions of images for frequencies lower than 14 Hz while the satellite and telescope structural design damps
microvibration in higher frequency ranges. It has been confirmed from the data taken on orbit that the remaining jitter is
less than 0.03 arcsec (3σ) on the Sun. This excellent performance makes a major contribution to successful precise polarimetric measurements with 0.2 – 0.3 arcsec
resolution.
K. Kobayashi now at NASA/Marshall Space Flight Center, Huntsville, AL 35812, USA. 相似文献
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Kinya Hibino Toshisuke Kashiwagi Shoji Okuno Kaori Yajima Yukio Uchihori Hisashi Kitamura Takeshi Takashima Mamoru Yokota Kenji Yoshida 《Astrophysics and Space Science》2007,309(1-4):541-544
We have developed radiation detectors using the new synthetic diamonds. The diamond detector has an advantage for observations
of “low/medium” energy gamma rays as a Compton telescope. The primary advantage of the diamond detector can reduce the photoelectric
effect in the low energy range, which is background noise for tracking of the Compton recoil electron. A concept of the Diamond
Compton Telescope (DCT) consists of position sensitive layers of diamond-striped detector and calorimeter layer of CdTe detector.
The key part of the DCT is diamond-striped detectors with a higher positional resolution and a wider energy range from 10 keV
to 10 MeV. However, the diamond-striped detector is under development. We describe the performance of prototype diamond detector
and the design of a possible DCT evaluated by Monte Carlo simulations.
相似文献
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Kazuhiro Tsukada Yuki Nakane Koshi Yamamoto Toshiyuki Kurihara Shigeru Otoh Kenji Kashiwagi Minjin Chuluun Sersmaa Gonchigdorj Manchuk Nuramkhaan Masakazu Niwa Tetsuya Tokiwa 《Island Arc》2013,22(2):227-241
We describe the mode of occurrence and geochemical characteristics of basalts, in the Khangai–Khentei belt in Mongolia, overlain by Middle Paleozoic radiolarian chert in an extensive accretionary complex. These basalts are greatly enriched in K, Ti, Fe, P, Rb, Ba, Th, and Nb in comparison to the composition of the mid‐ocean ridge basalts, indicative of within‐plate alkaline type. Ti/Y vs Nb/Y and MnO/TiO2/P2O5 ratios of the basalts also suggest within‐plate affinities. Considering the geochemical characteristics as well as the conformable relationship with the overlying radiolarian chert, the alkaline basalts were clearly not continental but formed a pelagic oceanic island. The mode of occurrence and geochemistry of the basalts show that the alkaline basaltic volcanic activity had taken place to form an oceanic island in the Paleozoic pelagic region sufficiently far from continents to allow radiolarian ooze accumulation. 相似文献
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Two modes of climatic control in the Holocene stalagmite record from the Japan Sea side of the Japanese islands 
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下载免费PDF全文 Tomomi Sone Akihiro Kano Kenji Kashiwagi Taiki Mori Tomoyo Okumura Chuan‐Chou Shen Masako Hori 《Island Arc》2015,24(3):342-358
The Holocene stalagmite FG01 collected at the Fukugaguchi Cave in Itoigawa, central Japan provides a unique high‐resolution record of the East Asian winter monsoon. Because of the climate conditions on the Japan Sea side of the Japanese islands, the volume of precipitation during the winter is strongly reflected in the stalagmite δ18O signal. Examination of the carbon isotopes and the Mg/Ca ratio of FG01 provided additional information on the Holocene climate in Itoigawa, which is characterized by two different modes separated at 6.4 ka. Dripwater composition and the correlation between the δ13C and Mg/Ca data of FG01 indicate the importance of prior calcite precipitation (PCP), a process that selectively eliminated 12C and calcium ions from infiltrating water from CO2 degassing and calcite precipitation. In an earlier period (10.0–6.4 ka), an increase in soil pCO2 associated with warming and wetting climate trends was a critical factor that enhanced PCP, and resulted in an increasing trend in the Mg/Ca and δ13C data and a negative correlation between the δ13C and δ18O profiles. A distinct peak in the δ13C age profile at 6.8 ka could be a response to an increase of approximately 10% in C4 plants in the recharge area. At 6.4 ka, the climate mode changed to another, and correlation between δ18O and δ13C became positive. In addition, a millennial‐scale variation in δ18O and pulsed changes in δ13C and Mg/Ca became distinct. Assuming that δ18O and PCP were controlled by moisture in the later period, the volume of precipitation was high during 6.0–5.2, 4.4–4.0, and 3.0–2.0 ka. In contrast, the driest interval in Itoigawa was during 0.2–0.4 ka, and broadly corresponds to the Little Ice Age. 相似文献
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Ando Haruo Maki Hideaki Kashiwagi Nobuhisa Ishii Yuuichi 《Journal of Oceanography》2021,77(6):843-858
Journal of Oceanography - Long-term trends of bottom-water concentrations of dissolved oxygen (DO), total nitrogen, and total phosphorus at 42 sites in Tokyo Bay were analyzed using monthly data... 相似文献
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