排序方式： 共有29条查询结果，搜索用时 15 毫秒
1.
Concern has grown regarding how public and private sectors should make effective use of local groundwater to alleviate negative impacts of water-supply cutoff following an earthquake event, which can be regarded as an emergency groundwater governance problem. Existing literature on groundwater governance, however, is based on the tacit assumption of groundwater utilization under normal social conditions, and scant consideration has been given to the role of groundwater following occurrence of a natural disaster. This study conducted questionnaire surveys to reveal how groundwater was used in three cities (Kumamoto, Sapporo, and Sendai) in Japan struck by large earthquakes between 2010 and 2020. Results revealed substantial differences between these cities in terms of groundwater utilization following earthquake occurrence. The time between the restoration of the electricity supply and restoration of the waterworks, and the social capital accumulated by local governments, are indicated as possible reasons for such differences. Analysis also identified policy challenges for improved groundwater governance in an emergency: (1) establishment of a strategy for emergency water supply through combined use of groundwater and other water sources, (2) enhancement of methods for timely inspection of groundwater quality following occurrence of a disaster, (3) maintenance of records of the number of registered disaster emergency wells (DEWs), (4) creation of methods for publicizing locational information on DEWs with adequate regard for the privacy of well owners, and (5) recognition of the importance of making DEWs part of overall disaster preparedness.
相似文献2.
José H.A. Sobral Vivian M. de Castilho M.A. Abdu Hisao Takahashi I. Paulino Ulisses A.C. Gasparelo Daniela C.S. Arruda Matheus Mascarenhas C.J. Zamlutti C.M. Denardini Daiki Koga A.F. de Medeiros R.A. Buriti 《Journal of Atmospheric and Solar》2011,73(11-12):1520-1528
In an effort to better understand the dynamics of westward velocities of the nocturnal F-region plasma, the climatology of the westward traveling plasma bubbles – WTB – occurring during quiettime is studied here. The climatology of the WTB is analyzed here based on airglow images obtained during 14 quiet days between 2001 and 2006 at the Brazilian station São João do Cariri (Geographic 7.45°S, 36.5°W, dip ～20°S). The frequency of occurrence of the WTB maximizes in the descending phase of the solar cycle. The WTB velocities ranged between ～20 and 40 ms?1. The frequency of occurrence had a peak value of only 3.65% at 2345 LT. The maximum occurrence of the WTB was in July–September. No WTB have been observed from November until April in all years 2001–2006. We show for the first time theoretically that the WTB dominant forcing mechanisms during geomagnetically quiet days are westward thermospheric winds. 相似文献
3.
Numerical study of the oxidation process of dimethylsulfide in the marine atmosphere 总被引：1，自引：0，他引：1
A box model, involving simple heterogeneous reaction processes associated with the production of non-sea-salt sulfate (nss-SO
4
2–
) particles, is used to investigate the oxidation processes of dimethylsulfide (DMS or CH3SCH3) in the marine atmosphere. The model is applied to chemical reactions in the atmospheric surface mixing layer, at intervals of 15 degrees latitude between 60° N and 60° S. Given that the addition reaction of the hydroxyl radical (OH) to the sulfur atom in the DMS molecule is faster at lower temperature than at higher temperature and that it is the predominant pathway for the production of methanesulfonic acid (MSA or CH3SO3H), the results can well explain both the increasing tendency of the molar ratio of MSA to nss-SO
4
2–
toward higher latitudes and the uniform distribution with latitude of sulfur dioxide (SO2). The predicted production rate of MSA increases with increasing latitude due to the elevated rate constant of the addition reaction at lower temperature. Since latitudinal distributions of OH concentration and DMS reaction rate with OH are opposite, a uniform production rate of SO2 is realized over the globe. The primary sink of DMS in unpolluted air is caused by the reaction with OH. Reaction of DMS with the nitrate radical (NO3) also reduces DMS concentration but it is less important compared with that of OH. Concentrations of SO2, MSA, and nss-SO
4
2–
are almost independent of NO
x
concentration and radiation field. If dimethylsulfoxide (DMSO or CH3S(O)CH3) is produced by the addition reaction and further converted to sulfuric acid (H2SO4) in an aqueous solution of cloud droplets, the oxidation process of DMSO might be important for the production of aerosol particles containing nss-SO
4
2–
at high latitudes. 相似文献
4.
Simulations of seasonal variations of sulfur compounds in the remote marine atmosphere 总被引：1，自引：0，他引：1
A photochemical box model is used to simulate seasonal variations in concentrations of sulfur compounds at latitude 40° S. It is assumed that the hydroxyl radical (OH) addition reaction to sulfur in the dimethyl sulfide (DMS) molecule is the predominant pathway for methanesulfonic acid (MSA) production, and that the rate constant increases as the air temperature decreases. Concentration of the nitrate radical (NO3) is a function of the DMS flux, because the reaction of DMS with NO3 is the most important loss mechanism of NO3. While the diurnally averaged concentration of OH in winter is a factor of about 8 smaller than in summer, due to the weak photolysis process, the diurnally averaged concentration of NO3 in winter is a factor of about 4–5 larger than in summer, due to the decrease of DMS flux. Therefore, at middle and high latitudes in winter, atmospheric DMS is mainly oxidized by the reaction with NO3. The calculated ratio of the MSA to SO2 production rates is smaller in winter than in summer, and the MSA to non-sea-salt sulfate (nssSO4
2-) molar ratio varies seasonally. This result agrees with data on the seasonal variation of the MSA/nssSO4
2- molar ratio obtained at middle and high latitudes. The calculations indicate that during winter the reaction of DMS with NO3 is likely to be a more important sink of NOx (NO+NO2) than the reaction of NO2 with OH, and to serve as a significant pathway of the HNO3 production. If dimethyl sulfoxide (DMSO) is produced through the OH addition reaction and is heterogeneously oxidized in aqueous solutions, half of the nssSO4
2- produced in summer may be through the oxidation process of DMSO. It is necessary to further investigate the oxidation products by the reaction of DMS with OH, and the possibility of the reaction of DMS with NO3 during winter. 相似文献
5.
6.
Célia Dalou Kenneth T. Koga Nobumichi Shimizu Julien Boulon Jean-Luc Devidal 《Contributions to Mineralogy and Petrology》2012,163(4):591-609
We experimentally determined F and Cl partition coefficients together with that of 19 trace elements (including REE, U-Th,
HFSE and LILE) between basaltic melt and lherzolite minerals: olivine, orthopyroxene, clinopyroxene, plagioclase and garnet.
Under conditions from 8 to 25 kbars and from 1,265 to 1,430°C, compatibilities of F and Cl are globally ordered as D
Cpx/melt > D
Opx/melt > D
Grt/melt > D
Ol/melt > D
Plag/melt, and D
F
mineral/melt is larger than D
Clmineral/melt. Four other major results were brought to light. (1) Chlorine partition coefficients positively correlate with the jadeite
component in orthopyroxene, and increase of the CaTs component promotes Cl incorporation in clinopyroxene. (2) Variations
of fluorine partition coefficients correlate strongly with melt viscosity. (3) F and Cl partition coefficients correlate with
the Young’s modulus (E
0) of pyroxene octahedral sites (M sites) and with Raman vibrational modes of pyroxenes. This demonstrates a fundamental interaction
between the M site of pyroxenes and the incorporation of F and Cl. (4) We also determined the parameters of the lattice-strain
model applied to 3+ cation trace elements for the two M sites in orthopyroxene and clinopyroxene: D
0M1, D
0M2, r
0M1, r
0M2, E
0M1 and E
0M2. 相似文献
7.
Fumihiro Koga 《Journal of Oceanography》1970,26(1):11-21
This species is the neritic animal in warm waters, especially a large number of the species appear in the tide pool in spring to summer season. The species has the adaptability to the environment, namely, the species is eurythermal and euryhaline organism. Each nauplius stage ofT. japonicus changed into the next stage in 18 to 20 hours. After hatching the nauplius developed into the copepodite stage in 3 to 5 days. The nauplius is disk-shaped in outline. A small antennule is 3-segmented. The antenna and mandible are the assistant oral organs for foods rather than swimming ones. On the antenna the coxa has the process with the strong cutting edge, the basipodite is extremely small, the long endopodite has a hook and a seta ventrally, and a hook, a seta and a spine terminally, and the long exopodite has the setae of which the number was changed according to the stage. On the mandible the coxa with a seta is a bulge. The endopodite is a small mound, on this mound there are a strong hook and a few setae which were changed according to the stage. The exopodite has a ventral seta and a small and a long thick terminal setae. The caudal appendages are rudimentary. The maxillule first appears as a seta on the 2nd stage. On the copedite stage ofT. japonicus the segment of body is short. The cephalothoracic segments are indistinguishable from the abdominal segments. It is the character of Harpacticoida that the antennules are small. On this copedodite there are 6 stages as in the nauplius, but the last stage is the adult stage. The 1st and the 2nd stages changed into the next stage in 18 to 20 hours as in the nauplius. The 3rd to the 5th stages changed into the next stage within 1 day. After hatching the nauplius developed into the adult by 10 days. The period of each stage fluctuates according to the amount of foods which were supplied to the animal. On the starved condition the development of this animal does not occur by any means. The most of male have mated with the adult female, but some of them mated with the earlier stage, especially the 2nd copepodite stage female. The female which developed into the adult produced the first brood in a few minutes to 3 days. A period of the adult stage is assumed 1 to 2 months. A female produced 5～10 broods. After hatching of the brood the next brood was bred in a few minutes to 1 day. The female which was 0.9 mm in the mean length produced 30 eggs per a brood. 相似文献
8.
T. Hammouda D. Andrault K. Koga T. Katsura A. M. Martin 《Contributions to Mineralogy and Petrology》2011,161(3):439-450
We have studied cation ordering in dolomite in situ as a function of pressure, temperature, and experimental time using the
multi-anvil apparatus and synchrotron radiation. Starting with ordered dolomite, we observe the onset of disordering taking
place at 950°C, while complete disordering is achieved at 1,070 (±20)°C, for pressures ranging between 3.37 and 4.05 GPa.
Pressure does not appear to have significant effect on the order/disorder transition over the investigated range. We find
that dolomite can reach its equilibrium ordering state above 900°C within duration of laboratory experiment (few hours), both
from disordered state and from ordered state. In addition, we have reversed the dolomite breakdown reaction [magnesite + aragonite = dolomite]
between 4.5 and 5.5 GPa, by monitoring diffraction peak intensity. We also have determined that dolomite is stable up to 7.4 GPa
at 1,100°C. We confirm some earlier studies where a change in slope (dP/dT) has been observed, but we find a non-zero slope in the low pressure range. Combining the values of entropy obtained from
dolomite degree of ordering with enthalpy values deduced from our bracketing of [magnesite + aragonite = dolomite] equilibrium,
we model the location of dolomite breakdown in the P–T space as a function of cation ordering. By comparing previous conflicting
studies, we show that, although kinetics of order/disorder is fast, disequilibrium dolomite breakdown is possible. Our modeling
shows that subducted disordered dolomite present in carbonated sediments could be decomposed to [magnesite + aragonite] at
lower pressure (3.5 GPa) than usually considered (>5 GPa). This 2-GPa (60 km) difference is valid on a fast subduction path
and is possible if disorder inherited from sedimentation is preserved. On a slow subduction path, however, dolomite breakdown
is encountered at about 250 km depth, which is 100 km deeper than currently considered. 相似文献
9.
Fumihiro Koga 《Journal of Oceanography》1970,26(4):195-202
The nauplius ofC. yamadai shows the shape of typicalCentropages nauplius, as inC. hamatus andC. abdominalis. The nauplii of genusCentropages are oval in shape; somewhat rounded anteriorly and slightly pointed posteriorly. The rostrum is comparatively large. A nauplius
eye is large at the proximal portion of the rostrum. There is a labrum with the minute spines on its posterior border. The
antennule of 3 segments is oar-liked in outline as inCalanus, but on the ventral margin of terminal segment there is no seta. The abdominal portion is not divided from the carapace like
that ofTemora orCalanus. There is no dorso-ventral flexure. The furcal setae are thick and long, and asymmetrical. An end seta which presents just
dorsally against to a median seta, elongates backwards.
The nauplius ofC. yamadai can be distinguished from nauplii of other species by the structure of appendages in the respective stages, but this nauplius
is easily identified by the coloured body. 相似文献
10.
Simple mixing as the major control of the evolution of volcanic suites in the Ecuadorian Andes 总被引：8，自引：0，他引：8
Pierre Schiano M. Monzier J.-P. Eissen H. Martin K. T. Koga 《Contributions to Mineralogy and Petrology》2010,160(2):297-312
Examination of an extensive major and trace element database for about 700 whole rocks from the Ecuadorian Andes reveals series
of local trends typified by three volcanoes: Iliniza and Pichincha from the Western Cordillera and Tungurahua from the Eastern
Cordillera. These local trends are included in a more scattered global trend that reflects typical across-arc chemical variations.
The scatter of the global trend is attributed to greater crustal contributions or decreasing melt fractions. Trace element
modelling shows that the local trends are consistent with mixing, and not with any fractional crystallization or progressive
melting dominated processes. These local trends are extendable to include samples from other Ecuadorian volcanoes, suggesting
that mixing processes are dominant throughout the region. Mixing model using trace and major element analyses identifies two
end-members: low-silica, basaltic and high-silica, dacitic magmas. It also shows that mixing occurred between magmas after
their segregation, rather than earlier mixing between the solid sources prior to melting. As a consequence, there must exist
efficient magma-mixing processes that can overcome the obstacles to mixing magmas with contrasting physical properties, and
can produce series of hybrid liquids over regional-scale. Model calculations show that estimated silicic end-members are primary
magmas and are not co-magmatic derivatives of the corresponding mafic end-members. Lavas of Ecuadorian volcanoes are likely
originated from magmas of contrasting origins, such as basaltic magmas generated by fluxed melting of peridotites in the mantle
wedge and dacitic, adakite-type magmas originating from the slab or the mafic lower crust. 相似文献