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1.
Long time behavior of one-dimensional self-gravitating system is numerically investigated. Itinerant behavior among quasiequilibria
is discovered, and its origin is clarified. The macroscopic distributions of the quasiquilibria are different from the isothermal
distribution, but the transient states, which appears between two successive quasiequilibria, resemble the isothermal distribution.
Averaging over the is itinerancy gives approximately the thermal equilibrium.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Blair Thornton Seiki Ohnishi Tamaki Ura Naoteru Odano Shun Sasaki Tsuneo Fujita Tomowo Watanabe Kaoru Nakata Tsuneo Ono Daisuke Ambe 《Marine pollution bulletin》2013
An estimated 3.5 ± 0.7 × 1015 Bq of 137Cs is thought to have been discharged into the ocean following the melt down at Fukushima Dai-ichi Nuclear Power Plant (F1NPP). While efforts have been made to monitor seafloor radiation levels, the sampling techniques used cannot capture the continuous distribution of radionuclides. In this work, we apply in situ measurement techniques using a towed gamma ray spectrometer to map the continuous distribution of 137Cs on the seafloor within 20 km of the F1NPP. The results reveal the existence of local 137Cs anomalies, with levels of 137Cs an order of magnitude higher than the surrounding seafloors. The sizes of the anomalies mapped in this work range from a few meters to a few hundreds of meters in length, and it is demonstrated that the distribution of these anomalies is strongly influenced by meter scale features of the terrain. 相似文献
3.
Mostafa Gouda TEMRAZ 《《地质学报》英文版》2012,86(2):440-446
Mineralogical, geochemical, and textural analyses of the white sandstones (Abu Thora Fm.) of Carboniferous in the Abu Rodeiyim region show that they are fluviomarine, well-sorted, high-purity, and high-grade silica SiO2 (average 99.56%). The results indicate that by simple treatment, the white sandstones can reach a high degree of purity, suitable for different industrial purposes (e.g. manufacture of silicon photovoltaic, crystal, and TV screens, art, and domestic and optical glass). 相似文献
4.
Yasser F Salama Gouda I Abdel-Gawad Shaban G Saber Soheir H El-Shazly G. Michael Grammer Sacit Özer 《Arabian Journal of Geosciences》2016,9(20):755
The present study aims to provide carbon-isotope curves for the Cenomanian to Turonian rudist-dominated successions in north Sinai. The high-resolution carbon-isotope curves obtained from north Sinai sections provide new insight for calibrating the age of rudists as well as for evaluating the effects of the oceanic anoxic event 2 (OAE2) on rudist communities. The primary goals are (1) to provide a high-resolution sequence stratigraphic framework for the Cenomanian-Turonian succession, (2) to use rudist and ammonite biostratigraphic data to distinguish the stratigraphic levels of the rudist species, and (3) to integrate the chemostratigraphic (δ13C) profile and the rudist levels to improve the biostratigraphy based on the rudist distributions and the carbon-isotope data. The recognition of three ammonite zones through the Cenomanian-Turonian succession was utilized to identify four temporally significant rudist levels indicative of the Lower Cenomanian, Middle Cenomanian, Upper Cenomanian, and Middle Turonian, respectively. Most of the rudists occur in the highstand deposits of medium-scale sequences. Carbon- and oxygen-isotopic analyses were carried out on both rudists and surrounding carbonate units. Based on the variations in the carbon-isotope signals, 12 chronostratigraphic segments were identified in the studied sections. The Cenomanian carbon-isotope segments (C23–C30) were obtained from the Halal Formation at Gabal Yelleg and Gabal Maaza sections, while the Turonian segments (C30–C34) were measured from the Wata Formation at Gabal Yelleg section. The carbon-isotope record from the studied sections is consistent with the trends documented in previous studies of the Tethyan realm. The Cenomanian-Turonian boundary is placed at the onset of falling carbon-isotope values (δ13C) from 2.61 to ?0.25‰ in the upper part of OAE2 with the carbon-isotope segment C30 at Gabal Yelleg. The negative shift in δ13C values (C33) occurred in the Middle Turonian lowstand deposits characterizing the global sea level fall during this interval. 相似文献
5.
In recent years, hot summers (HS) have played an important role in affecting people’s health and causing natural disasters. However, it is not very clear what HS should be attributed to. In order to investigate that, the anomalous of anticyclone associated with HS in the Mediterranean and North China is examined and compared by using data during the time period 1949~2018. Statistical analysis shows that summer temperature in the Mediterranean and North China is revealing a good correlation when removing the global warming trend. The composite results indicate that the anomalous warming during HS over different regions is both dominantly controlled by an anomalous anticyclone, which enhances the subsidence adiabatic heating of the temperature. Furthermore, the subtropical high (STH) variations faithfully represent the fluctuations in summer temperature over the Mediterranean (cor = 0.78) and North China (cor = 0.80). The anticyclonic anomalies over both focus areas are associated with North Atlantic and Northwest Pacific sea surface temperature (sst), respectively. These results indicate that the total influence of the STH position anomaly should be taken into consideration in different places during HS. However, whether such atmosphere-ocean feedback can be improved by numerical experiments is worthy to be further studied. 相似文献
6.
Masahiro Nagashima Naoteru Gouda 《Monthly notices of the Royal Astronomical Society》2001,325(4):L13-L18
We have examined the effects of the ultraviolet background radiation (UVB) on the colour–magnitude relation (CMR) of elliptical galaxies in clusters of galaxies in the hierarchical clustering scenario by using a semi-analytic model of galaxy formation. In our model the UVB photoionizes gas in dark haloes and suppresses the cooling of the diffuse hot gas on to galaxy discs. By using a semi-analytic model without the effect of the UVB, Kauffmann & Charlot found that the CMR can be reproduced by strong supernova heating because such supernova feedback suppresses the chemical enrichment in galaxies, especially for small galaxies. We find that the CMR also becomes bluer because of the UVB, in a different way from the effect of supernova feedback. While supernova feedback suppresses the chemical enrichment by a similar mechanism to galactic winds, the UVB suppresses the cooling of the hot gas. This induces suppression of the metallicity of the intracluster medium (ICM). In our model we find that the existence of the UVB can plausibly account for an observed ICM metallicity that is equal to nearly 0.3 times the solar value, and that in this case we can reproduce the CMR and the metallicity of the ICM simultaneously. 相似文献
7.
Naoteru Gouda Takuji Tsujimoto Yukiyasu Kobayashi Tadashi Nakajima Naoki Yasuda Hideo Matsuhara 《Astrophysics and Space Science》2002,280(1-2):89-94
JASMINE is the name of a Japanese infrared (K-band) scanning astrometric satellite. JASMINE (I and/or II-project) is planned to be launched between 2013 and 2017 and will
measure parallaxes and proper motions with the precision of 10μas at K≃ 12 - 15 mag. JASMINE will observe a few hundred million stars belonging to the disk and the bulge components of our Galaxy,
which are hidden by the interstellar dust extinction in optical bands. Furthermore, JASMINE will also obtain photometry of
stars in K, J and H-bands. The main objective of JASMINE is to study the most fundamental structure and evolution of the disk and the bulge components
of the Milky Way Galaxy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Summary. One hundred and fifty oriented samples were collected from 12 sites from the Tertiary basalts of Wadi Abu Tereifiya (30.0°N, 32.1° E). After alternating field demagnetization the mean direction of the natural remanent magnetization is, D = 187.9°, I = -20.8° with α95 = 5.8°. This yields a palaeopole at 69.4°N, 188.3° E.
Also, 30 oriented samples were collected from two sites from Mandisha in Bahariya Oasis (28.4°N, 28.9° E). After cleaning, the mean direction of the NRM is D = 191.0°, I = 5.2° with α95 = 9.9°. This yields a palaeopole position at 58.2°N, 186.7° E.
Besides, the NRM of 70 oriented samples collected from seven dioritic dykes from Wadi Abu Shihat (26.3°N, 33.2° E) was found to have a mean direction, D = 142.0°, I = -0.3°, which leads to a palaeopole position at, 44.9°N, 273.0° E. This agrees with other Mesozoic pole positions from Africa. 相似文献
Also, 30 oriented samples were collected from two sites from Mandisha in Bahariya Oasis (28.4°N, 28.9° E). After cleaning, the mean direction of the NRM is D = 191.0°, I = 5.2° with α
Besides, the NRM of 70 oriented samples collected from seven dioritic dykes from Wadi Abu Shihat (26.3°N, 33.2° E) was found to have a mean direction, D = 142.0°, I = -0.3°, which leads to a palaeopole position at, 44.9°N, 273.0° E. This agrees with other Mesozoic pole positions from Africa. 相似文献
9.
Rajendra Sharma H. C. Gouda R. K. Singh B. V. Nagaraju 《Journal of the Geological Society of India》2012,79(1):11-29
The study of aeromagnetic data over parts of Assam-Meghalaya has delineated major discontinuities representing faults/ fractures/
contacts/ shears and magnetic body axes, which helped in understanding the regional and structural setup of the area. The
known Barapani and Dapsi Thrusts, Dudhnai Fault and three strong magnetic anomalies with reverse magnetisation have been delineated.
The quantitative analysis of aeromagnetic data brought out the depths of magnetic interfaces and the magnetic picture of different
layers, which also helped in understanding the regional and structural setup. The contact modeling across few profile sections
showed the depths to the top of contacts and the map of magnetic-basement-depth-model revealed the undulations of the basement.
Magnetic body axes of several magnetic anomalies and also several magnetic discontinuities representative of faults/ fractures/
contacts/ shears system in the area along with five potential blocks for mineral prospecting are the main outcome of this
exercise. The seismotectonic activity associated with the magnetic features has also been studied to understand the structural
setup. 相似文献
10.
Yasser SALAMA Michael GRAMMER Shaban SABER Soheir EL-SHAZLY Gouda ABDEL-GAWAD 《《地质学报》英文版》2018,92(1):286-310
The Lower Cretaceous sections in northern Sinai are composed of the Risan Aneiza (upper
Barremian-middle Albian) and the Halal (middle Albian-lower Cenomanian) formations. The facies
reflect subtle paleobathymetry from inner to outer ramp facies. The inner ramp facies are peritidal,
protected to open marine lagoons, shoals and rudist biostrome facies. The inner ramp facies grade
northward into outer ramp deposits. The upper Barremian-lower Cenomanian succession is subdivided
into nine depositional sequences correlated with those recognized in the neighbouring Tethyan areas.
These sequences are subdivided into 19 medium-scale sequences based on the facies evolution, the
recorded hardgrounds and flooding surfaces, interpreted as the result of eustatic sea level changes and
local tectonic activities of the early Syrian Arc rifting stage. Each sequence contains a lower
retrogradational parasequence set that constituted the transgressive systems tracts and an upper
progradational parasequence set that formed the highstand systems tracts. Nine rudist levels are
recorded in the upper Barremian through lower Cenomanian succession at Gabal Raghawi. At Gabal
Yelleg two rudist levels are found in the Albian. The rudist levels are associated with the highstand
systems tract deposits because of the suitability of the trophic conditions in the rudist-dominated ramp. 相似文献