Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ^(232)Th,^(238)U and ^(40)K are ranged from 27.88 to 45...Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ^(232)Th,^(238)U and ^(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ^(232)Th in the present study is 1.19 times higher than world median value while the activity of ^(238)U and ^(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ^(232)Th,^(238)U and ^(40)K in soil samples is 36.99 nGy·h^(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.展开更多
In terms of formation mechanisms of linear dunes,there are open arguments for their widespread distribution and multi-morphological diversities.In order to clarify the formation mechanism of linear dunes of Qarhan Sal...In terms of formation mechanisms of linear dunes,there are open arguments for their widespread distribution and multi-morphological diversities.In order to clarify the formation mechanism of linear dunes of Qarhan Salt Lake,we used pattern analysis method to analyze the statistical characteristics and spatial variation of their pattern parameters.Except at the west-northwest margin,the pattern parameters showed regular spatial variation from the up-middle part towards the downwind end of the dune field.Based on the cumulative probability plots for inter-crest spacing and crest length,we divided the linear dunes into three groups,which corresponding to the three evolution stages of these dunes.The first group comprises erosional relics,with shorter crests,smaller inter-crest spacing and more random dune orientation.The second group comprises dunes whose sand supply is just sufficient to maintain stability and these dunes are approaching the net erosion stage.The crest length and inter-crest spacing of these dunes are much larger than those of the first group,and dune orientation is closer to the resultant drift direction （RDD） .The last group comprises linear dunes that are still undergoing vertical accretion and longitudinal elongation,which follows the RDD of the modern wind regime.The presence of regular spatial variation of pattern parameters and a similar geometry with the vegetated linear dunes suggest that deposition and erosion coexist in the development and evolution of linear dunes of Qarhan Salt Lake,i.e.deposition predominates at the downwind end of linear dunes in the vertical accretion and longitudinal elongation stage,whereas erosion mainly occurs at the upwind end of linear dunes in the degradation stage.Therefore,the formation mechanism of linear dunes in Qarhan Salt Lake can be reasonably explained by the combination of depositional and erosional theories.展开更多
Wazuka town in Kyoto prefecture has the largest farmland for Uji green tea on the steep hillsides. In 1953, this area suffered from flood disaster due to the heavy rainfall along with the valley wind. In this area, di...Wazuka town in Kyoto prefecture has the largest farmland for Uji green tea on the steep hillsides. In 1953, this area suffered from flood disaster due to the heavy rainfall along with the valley wind. In this area, diluvia, Osaka strata and granite are outcropped along the Wazuka fault, and many old landslides in small scale could be identified. The River Basin Control Bureau has an experimental site locating on Ishidera area in Wazuka, where there was a house that was built about 150 years ago, and the habitants migrated after the 1953 flood. This area was developed for lots and housing during the economic bubble years around 1990, but was abandoned due to the occurrence of a small landslide and the inclination of concrete wall. To understand the distribution of ground water streams, 1 m-depth-ground temperature survey method and sound survey method were used. Using these methods, ground water streams were detected at the Kizu river bank gate site, at salt pan site gate trail, and on Ishidera landslide observatory. Based on the survey results, the construction sites of the wells for the drainage, steel-sheet piles for the river bank and watergate trails for the salt field area were suggested.展开更多
Salt stratified Lake Shira has been the subject of an extensive body of research because of its central role in existence of the resort area of Khakassia.The aim of previous research has been directed at water quality...Salt stratified Lake Shira has been the subject of an extensive body of research because of its central role in existence of the resort area of Khakassia.The aim of previous research has been directed at water quality issues(e.g.Aquatic ecology).Studies of Lake Shira physical dynamics relevant to the present work include:general observations of展开更多
A linear stability analysis is applied to a system consisting of a linear magneto-fluid layer overlying a porous layer affected by rotation and salt concentration on both layers. The flow in the fluid layer is governe...A linear stability analysis is applied to a system consisting of a linear magneto-fluid layer overlying a porous layer affected by rotation and salt concentration on both layers. The flow in the fluid layer is governed by Navier-Stokes’s equations and while governed by Darcy-Brinkman’s law in the porous medium. Numerical solutions are obtained using Legendre polynomials. These solutions are studied through two modes of instability: stationary instability and overstability when the heat and the salt concentration are effected from above and below.展开更多
文摘Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ^(232)Th,^(238)U and ^(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ^(232)Th in the present study is 1.19 times higher than world median value while the activity of ^(238)U and ^(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ^(232)Th,^(238)U and ^(40)K in soil samples is 36.99 nGy·h^(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.
基金funded by the National Basic Research Program of China (2013CB956000)the National Natural Science Foundation of China (41171010,41371102,41301003)
文摘In terms of formation mechanisms of linear dunes,there are open arguments for their widespread distribution and multi-morphological diversities.In order to clarify the formation mechanism of linear dunes of Qarhan Salt Lake,we used pattern analysis method to analyze the statistical characteristics and spatial variation of their pattern parameters.Except at the west-northwest margin,the pattern parameters showed regular spatial variation from the up-middle part towards the downwind end of the dune field.Based on the cumulative probability plots for inter-crest spacing and crest length,we divided the linear dunes into three groups,which corresponding to the three evolution stages of these dunes.The first group comprises erosional relics,with shorter crests,smaller inter-crest spacing and more random dune orientation.The second group comprises dunes whose sand supply is just sufficient to maintain stability and these dunes are approaching the net erosion stage.The crest length and inter-crest spacing of these dunes are much larger than those of the first group,and dune orientation is closer to the resultant drift direction （RDD） .The last group comprises linear dunes that are still undergoing vertical accretion and longitudinal elongation,which follows the RDD of the modern wind regime.The presence of regular spatial variation of pattern parameters and a similar geometry with the vegetated linear dunes suggest that deposition and erosion coexist in the development and evolution of linear dunes of Qarhan Salt Lake,i.e.deposition predominates at the downwind end of linear dunes in the vertical accretion and longitudinal elongation stage,whereas erosion mainly occurs at the upwind end of linear dunes in the degradation stage.Therefore,the formation mechanism of linear dunes in Qarhan Salt Lake can be reasonably explained by the combination of depositional and erosional theories.
文摘Wazuka town in Kyoto prefecture has the largest farmland for Uji green tea on the steep hillsides. In 1953, this area suffered from flood disaster due to the heavy rainfall along with the valley wind. In this area, diluvia, Osaka strata and granite are outcropped along the Wazuka fault, and many old landslides in small scale could be identified. The River Basin Control Bureau has an experimental site locating on Ishidera area in Wazuka, where there was a house that was built about 150 years ago, and the habitants migrated after the 1953 flood. This area was developed for lots and housing during the economic bubble years around 1990, but was abandoned due to the occurrence of a small landslide and the inclination of concrete wall. To understand the distribution of ground water streams, 1 m-depth-ground temperature survey method and sound survey method were used. Using these methods, ground water streams were detected at the Kizu river bank gate site, at salt pan site gate trail, and on Ishidera landslide observatory. Based on the survey results, the construction sites of the wells for the drainage, steel-sheet piles for the river bank and watergate trails for the salt field area were suggested.
文摘Salt stratified Lake Shira has been the subject of an extensive body of research because of its central role in existence of the resort area of Khakassia.The aim of previous research has been directed at water quality issues(e.g.Aquatic ecology).Studies of Lake Shira physical dynamics relevant to the present work include:general observations of
文摘A linear stability analysis is applied to a system consisting of a linear magneto-fluid layer overlying a porous layer affected by rotation and salt concentration on both layers. The flow in the fluid layer is governed by Navier-Stokes’s equations and while governed by Darcy-Brinkman’s law in the porous medium. Numerical solutions are obtained using Legendre polynomials. These solutions are studied through two modes of instability: stationary instability and overstability when the heat and the salt concentration are effected from above and below.
