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121.
122.
The effects of long-term preservation on flow cytometric parameters of natural oceanic populations of pico-and nanophytoplankton
have been examined. Populations collected at oligotrophic subtropical and subarctic locations in the North Pacific were fixed
with glutaraldehyde and frozen in liquid nitrogen, according to Vaulot et al. (1989). During six months’ storage, chlorophyll red fluorescence declined in all the groups examined, while forward light
scatter was enhanced in Synechococcus and Prochlorococcus, and weakened in nanoeucaryotes. Cell loss was not significant except for Synechococcus. Caution is required when analyzing flow cytometric data of samples stored for more than a month. 相似文献
123.
A. M. Swinbank A. C. Edge Ian Smail J. P. Stott M. Bremer Y. Sato C. van Breukelen M. Jarvis I. Waddington L. Clewley J. Bergeron G. Cotter S. Dye J. E. Geach E. Gonzalez-Solares P. Hirst R. J. Ivison S. Rawlings C. Simpson G. P. Smith A. Verma T. Yamada 《Monthly notices of the Royal Astronomical Society》2007,379(4):1343-1351
124.
The flux–gradient relationships in the unstable roughness sublayer (RSL) over an open canopy of black spruce forest were examined
using long-term observations from an instrumented tower. The observed gradients normalised with the surface fluxes and height
above the zero-plane displacement showed differences from a universal function established in the surface layer. The magnitude
of differences was not constant throughout the year even at the same observation height. Also the magnitude of the differences
was different for each scalar, and scalar similarity in the context of the flux–gradient relationship did not always hold.
The variation of the differences was explained by the relative contribution of overstorey vegetation to the total flux from
the entire ecosystem. This suggests that a mismatch of the vertical source/sink distributions between scalars leads to a different
strength of the near-field dispersion effect for each scalar, and this resulted in inequality of eddy diffusivity among scalars
in the RSL. An empirical method that predicts the magnitude of differences is proposed. With this method, it is possible to
estimate the eddy diffusivity of scalars provided that the relative contribution of overstorey vegetation to the total flux
from the ecosystem is known. Also this method can be used to estimate the eddy diffusivity for scalars whose primary sources
are at ground level, such as methane and nitrous oxide. 相似文献
125.
J. Hansen W. Rossow B. Carlson A. Lacis L. Travis A. Del Genio I. Fung B. Cairns M. Mishchenko M. Sato 《Climatic change》1995,31(2-4):247-271
We describe the rationale for long-term monitoring of global climate forcings and radiative feedbacks as a contribution to interpretation of long-term global temperature change. Our discussion is based on a more detailed study and workshop report (Hansenet al., 1993b). We focus on the potential contribution of a proposed series of inexpensive small satellites, but we discuss also the need for complementary climate process studies and ground-based measurements. Some of these measurements could be made inexpensively by students, providing both valuable climate data and science educational experience. 相似文献
126.
127.
K. Sato 《Mineralium Deposita》1980,15(3):327-334
The occurrence of fluorite deposits in Japan is limited in the provinces characterized by tin and tungsten mineralization within Southwest Japan. The deposits were formed near acidic igneous rocks of Cretaceous to Tertiary age. The ores in limestone are generally associated with skarn and metallic ore minerals such as cassiterite, scheelite and chalcopyrite. Granitic rocks in the provinces are the ilmenite-series (Ishihara, 1977) having enhanced fluorine contents and high initial strontium ratios. A reducing condition of the ilmenite-series granitic magma may have been more favorable for the concentration of fluorine in the residual magma because of the crystallization of relatively Fe-rich mafic minerals. Presence of thick crust bearing carbonaceous matter at the site of magmatism could have involved in the enrichment of fluorine as well as the reducing condition. 相似文献
128.
The variation of displacement along fifteen traces of minor normal faults was measured in the multilayered Quaternary sediments of Kyushu, Japan. In the diagrams of distance along a fault trace (L) vs displacement (D) two distinct types of faults, a cone-shaped L-D pattern (C-type) and mesa-shaped one (M-type), were detected. Because the L-D pattern is subject to slip-parallel strain in the wall rocks, a D-constant pattern is ascribed to the competent (rigid) material and a D-variable pattern is found in the incompetent material. Therefore, C-type faults are characteristic of homogeneous incompetent materials, whereas M-types are representative of faults that cut through a rigid unit. However, the steep slopes in the flanking sections of M-type patterns indicate that the faulting of a rigid unit should terminate in a strain absorber of incompetent materials. The concept of lithologic control in the L-D pattern is important for the better understanding of faulting processes as well as the localization of faults. 相似文献
129.
Satoh?ToshimiEmail author Hiroshi?Kawase Tomotaka?Iwata Sadanori?Higashi Sato?Toshiaki Huey-Chu?Huang 《Journal of Seismology》2004,8(4):545-558
The 1999 Chi-Chi, Taiwan earthquake, MW = 7.6, caused severe damage in the near-fault region of the earthquake. In order to evaluate site effects in the near-field strong motions we estimate S-wave velocity structures of sediments at four sites using array records of microtremors. We also recalculated S-wave velocity structures at other four sites previously reported. To show the validity of the estimated S-wave velocity structures we separate empirical site responses from aftershock records using the generalized inversion method and show the agreement between empirical and theoretical site responses. We also show an observed fact that suggests soil nonlinearity during the Chi-Chi earthquake by comparing horizontal-to-vertical spectral ratios (HVRs) for main shock records with HVRs for aftershock records. Then we calculate one-dimensional equivalent-linear site responses using the estimated S-wave velocity structures and the main shock records observed on the surface. It is found that site amplification due to thick (about 6 km) sediments is one of the important factors for explaining the long-period velocity pulses of about 5 to 10 sec observed at sites in the footwall during the Chi-Chi earthquake. It is also found that the theoretical site responses of shallow soft sediments at sites that sustained severe damage in the hanging wall shows significant amplification around 1 sec. As the amplitude of velocity pulses with period around 1 sec is most critical in causing damage to ordinary buildings of moderate heights, our results suggest that the 1-sec period velocity pulses, amplified by the site response of shallow sediments should contribute to the severe damage during the Chi-Chi earthquake. 相似文献
130.
Kosei Komuro Hiroshi Kubota Tokiyuki Sato Yoshimichi Kajiwara Shojiro Tanimura 《Resource Geology》2004,54(4):425-436
Abstract. A comprehensive investigation was carried out on the distribution of both trace fossils and sulfur isotopes in mud-stones in the Hokuroku district, northeast Japan, in the hope of delineating the depositional environment of the mudstones in which the Kuroko deposits are embedded. The mudstones are generally massive in structure and usually contain large trace fossils, being indicative of an aerobic biofacies. On the other hand, some mudstones in and above the Kuroko ore horizon are partly laminated and usually contain smaller trace fossils, being assignable to an anaerobic or dysaerobic biofacies. The δ34 S values of sulfides in the mudstones above and below the ore horizon range from -40 to -12 %o, indicating mostly oxic depositional conditions in equilibrium with the inferred aerobic biofacies. In the mudstones in the ore horizon, the δ34 S values exhibit regionally discriminated variations: -44 to -12 %o in areas far (>1 km) from the known Kuroko deposits and -24 to +6 %o in areas closer to them. The latter high δ34 S group implies the temporal occurrence of local anoxic basins in the vicinity of the known Kuroko deposits. At the time of late Nishikurosawa Stage (i.e. the currently assumed Kuroko metallogenic epoch), an intense oceanic stagnation is suggested to have taken place to form the local anoxic basins responsible for the formation and preservation of Kuroko deposits. This oceanic environmental event is considered to be most likely due to increasing biological productivity primarily triggered and enhanced by upwelling of NADW in the paleo-Sea of Japan at that time. 相似文献