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1.
A model calculation to predict infrared Shuttle flow due to the radiative relaxation of vibration of the NO molecule is presented. Space Shuttles hit atmospheric NO molecules at a very high speed (≈ 8 km s?1) and excite vibrational and rotational motions up to the temperature of 54,000 K. With the electric dipole radiation of Δν = 1, 2, 3, and particularly 4 (ν is the vibrational quantum number), the excited NO molecules emit infrared radiation before they collide with other molecules. The total radiation power is estimated to be 170AμW, where A is the cross-section area of the Shuttle in m2 if no adsorption of the NO molecule takes place on the Shuttle surface. The intensity of each infrared line is calculated as a function of time, including all vibrational states up to ν = 35. For example, the 5039 cm?1 line (ν = 24 → 20) has a maximum intensity of about 2.3 × 10?21 W molecule at around 0.2 ms, which corresponds to 80 cm from the Shuttle surface if the recoil speed of the molecules is 4 km s?1. 相似文献
2.
Photographic observations were carried out at depths of the shelf edge at the mouth of Uchiura Inlet, Suruga Bay, central Japan in order to clarify the life style of the isocrinid stalked crinoid,Metacrinus rotundus (Echinodermata). The distribution of the species was found to be restricted to a narrow area where boulders and rock outcrops were locally present. Mean density of the crinoid was 0.05 m–2, and this value was an order of magnitude smaller than that of the deeper isocrinid,Diplocrinus wyvillethomsoni, reported from the Bay of Biscay.Metacrinus rotundus formed a parabolic filtration fan with its arms recurved into the bottom current, and was thought to be a passive suspension feeder elevating the fan into the water column by its stalk. The distal half of the stalk lay along the hard substratum and about ten groups of cirri grasped the substratum. This mode of attachment was similar to that ofCenocrinus rather than that ofDiplocrinus. Metacrinus rotundus collect food at the layer between 10 and 50 cm above the sea floor, and do not utilize a higher layer even when this layer could be utilized by climbing over a larger boulder. Resuspended benthic materials are thought to be important as a food source forM. rotundus, and the crinoids seek not only locations of stronger currents but also the position where much resuspended matter is available. 相似文献
3.
Yoshiyuki Nozaki 《Journal of Oceanography》1991,47(5):221-225
An idea has been proposed to recover and dispose of the fossil-fuel CO2 generated by stationary power plants into the deep sea, thereby reducing the CO2 emission to the atmosphere. The assessment of its environmental effects and risks is essential for developing new technology for the recovery/disposal system, which has recently received growing attention in Japan.The simple calculation made here did not yield any decisively significant environmental risks so far. However, a further detailed study is needed for the consequences of lowering local pH and the abrupt dissolution of CaCO3 in the deep-sea sediments. It is also shown that, on longer term, the atmospheric concentration of CO2 may be influenced by the degree at which the reaction between the disposed fossil-fuel CO2 and the sedimentary CaCO3 takes place under such conditions. At any rate, the problem should be brought to serious scientific attention much like the case of ocean dumping of radioactive wastes. 相似文献
4.
Momentum and heat flux were measured with a sonic anemometer at the Marine Observation Tower in the port of ItÔ. Under unstable conditions (T
w
-T
a
=3C4C), using the eddy correlation method, results show thatCd=(1.2±0.3)×10–3 andCh=(1.5±0.3)×10–3 at 5.5 m above mean sea level except for the case of weak winds.An unexpected relationship betweenCd and (–z/L) was observed, that is,Cd decreases as (–z/L) increases. If roughness variation over the sea is taken into account, we can explain the decrease in the range of (–z/L) less than 1, but not in the range greater than 1. This is due to a strong instability effect and the change of roughness class, from moderately rough to smooth. 相似文献
5.
Koichiro Fujinaga Tatsuo Nozaki Takazumi Nishiuchi Kiyoko Kuwahara Asuhiro Kato 《Resource Geology》2006,56(4):399-414
Abstract. Major and trace element contents are reported for Permian manganese ore and associated greenstone from the Ananai manganese deposit in the Northern Chichibu Belt, central Shikoku, Japan. The manganese deposit occurs between greenstone and red chert, or among red chert beds. Chemical compositions of manganese ore are characterized by enrichments in Mn, Ca, P, Co, Ni, Zn, Sr and Ba, and negative Ce and positive Eu anomalies relative to post-Archean average Australian Shale (PAAS). Geochemical features of the manganese ore are similar to those of modern submarine hydrother-mal manganese deposits from volcanic arc or hotspot setting. In addition, geochemical characteristics of the greenstone closely associated with the Ananai manganese deposit are analogous to those of with-in plate alkaline basalt (WPA). Consequently, the Ananai manganese deposit was most likely formed by hydrothermal activity related to hotspot volcanism in the Panthalassa Ocean during the Middle Permian. This is the first report documenting the terrestrially-exposed manganese deposit that was a submarine precipitate at hotspot. 相似文献
6.
Hiroshi Amakawa Yoshiyuki Nozaki Jing Zhang Hisao Nagai 《Geochimica et cosmochimica acta》2004,68(4):715-727
Four vertical profiles of the concentration and isotopic composition of Nd in seawater were obtained in the western North Pacific. Two profiles from the Kuroshio Current regime showed congruently that although the Nd concentration increases gradually with depth, its isotopic composition varies significantly with depth depending upon the water mass occupying the water column. The high-salinity Kuroshio waters originating from the North Pacific Tropical Water (NPTW) carry the least radiogenic Nd (?Nd = −7.4 to −8.7) to this region at ∼250 m from the western margin continental shelves, most likely from the East China Sea. The Nd isotopic compositions in the North Pacific Intermediate Water (NPIW) that occurs at 600 to 1000 m in the subtropical region are fairly uniform at ?Nd = −3.7. The profile data from the ∼38° to 40°N Kuroshio/Oyashio mixed water region off Sanriku of Honshu, Japan, also suggest that the newest NPIW with ?Nd = −3.2 is formed there by the mixing of various source waters, and the radiogenic component of Nd is derived mainly from the Oyashio waters.In the Pacific Deep Water (PDW) below ∼1000 m, the Nd isotopic composition is neither vertically nor horizontally homogeneous, suggesting that it serves as a useful tracer for sluggish deep water circulation as well. Two profiles from the Izu-Ogasawara Trench showed a minimum ?Nd value at ∼2000 m, suggesting that there exists a horizontal advective flow in the vicinity of Honshu, Japan. There is some evidence from other chemical properties to support this observation. The waters below 4000 m including those within the trench in the subtropical region have ?Nd values of around −5, suggesting that the deep waters are fed from the south along the western boundary, ultimately from the Antarctic Bottom Water (AABW) in the South Pacific. This extends up to ∼40°N along the Japanese Islands. In the subarctic region (>∼42°N), the waters have more radiogenic Nd with ?Nd > −4.0 throughout the water column, presumably due to the supply of Nd by weathering in such igneous provinces as the Kuril-Kamchatska-Aleutian Island chain. The lateral inhomogeneity of the Nd isotopic composition in PDW suggests that there may be different circulation and mixing regimes in the North Pacific Basin. 相似文献
7.
Rare Earth, Major and Trace Elements in the Kunimiyama Ferromanganese Deposit in the Northern Chichibu Belt, Central Shikoku, Japan 总被引:1,自引:0,他引:1
Yasuhiro Kato Koichiro Fujinaga Tatsuo Nozaki Kentaro Nakamura Ryuji Ono Hiroshi Osawa 《Resource Geology》2005,55(4):291-300
Abstract. Rare earth, major and trace element geochemistry is reported for the Kunimiyama stratiform ferromanganese deposit in the Northern Chichibu Belt, central Shikoku, Japan. The deposit immediately overlies greenstones of mid-ocean ridge basalt (MORB) origin and underlies red chert. The ferromanganese ores exhibit remarkable enrichments in Fe, Mn, P, V, Co, Ni, Zn, Y and rare earth elements (excepting Ce) relative to continental crustal abundance. These enriched elements/ Fe ratios and Post-Archean Average Australian Shale-normalized REE patterns of the ferromanganese ores are generally analogous to those of modern hydrothermal ferromanganese plume fall-out precipitates deposited on MOR flanks. However in more detail, Mn and Ti enrichments in the ferromanganese ores are more striking than the modern counterpart, suggesting a significant contribution of hydrogenetic component in the Kunimiyama ores. Our results are consistent with the interpretation that the Kunimiyama ores were umber deposits that primarily formed by hydrothermal plume fall-out precipitation in the Panthalassa Ocean during the Early Permian and then accreted onto the proto-Japanese island arc during the Middle Jurassic. The presence of strong negative Ce anomaly in the Kunimiyama ores may indicate that the Early Permian Panthalassa seawater had a more striking negative Ce anomaly due to a more oxidizing oceanic condition than today. 相似文献
8.
By coupling FEM and BEM, a numerical method was developed for dynamic response analyses of dam–foundation–reservoir systems in the time domain. During formulation, the weighted residual procedure was applied to the coupling of several equations of motion for solid and fluid in the FE and BE regions, and an algorithm similar to the Newmark beta procedure was finally obtained. The algorithm is advantageous in that it takes into account all the effects of dam–foundation, dam–reservoir and reservoir–foundation interactions, as well as of the absorption of both elastodynamic and hydrodynamic waves at the boundaries of the foundation and the reservoir. To demonstrate the validity of the present method, the impulsive response of a dam–foundation–reservoir system was calculated using the algorithm, and showed a good agreement with the existing results obtained by other researchers. 相似文献
9.
Ten GEOSECS profiles from the North Pacific have been analyzed for210Pb. GEOSECS226Ra data on the same profiles are used to calculate210Pb excess or deficiency relative to secular equilibrium. The resultant profiles are divisible into a thermocline zone (<2000m) showing an expected decrease with depth, a mid-water zone of about 2000 m showing small constant deficiencies with a zone of increasing deficiency to a bottom zone of about 1000 m having the highest deficiency virtually invariant with depth. The exponentially decreasing portion in the thermocline yields a “diffusion” coefficient of 3 cm2/s. The mid-water deficiencies yield ? model residence times of 400 years northeast of Hawaii decreasing to 100 years at the most marginal stations. 相似文献
10.
Jun Takahashi Tatsuo Suzuki Igor V Polyakov Kohei Mizobata Moto Ikeda Fancois J.Saucier Markus Meier 《极地研究(英文版)》2008,19(2):159-167
This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature (AWCT) in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT ( C = 0.75 ) at 0- lag. The modeled North Atlantic Oscillation (NAO) index has a significant correlation with the heat transport ( C = 0.37 ). The observed AWCT has a significant correlation with both the modeled AWCT ( C =0.49) and the heat transport ( C =0.41 ). However, the modeled NAO index does not significantly correlate with either the observed AWCT ( C = 0.03 ) or modeled AWCT ( C = 0.16 ) at a zero-lag, indicating that the Arctic climate system is far more complex than expected. 相似文献