Based on the 3D electron's radial wave function of Co 2+ free ion,a Nephelauxetic effect modifying factor to modify the radial wave function is introduced when Co 2+ cations are put into the crystal fie...Based on the 3D electron's radial wave function of Co 2+ free ion,a Nephelauxetic effect modifying factor to modify the radial wave function is introduced when Co 2+ cations are put into the crystal field of Zn 1-x Co x Se.With the modified wave functions,the optical transitions for Zn 1-x Co x Se crystals are calculated.Moreover,based on the first principle of physics,the influences of high pressure to the Nephelauxetic effect modifying factor is considered,and the high pressure blue shift for the Zn 1-x Co x Se crystal absorption spectra are calculated and a shift rate of d E /d p =0 45meV/GPa is obtained.展开更多
A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of...A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of the road surface from noise is performed based on the fuzzy clustering of normal vectors, with which the mean value is calculated and the projecting plane of point cloud is created to obtain the geometric model accordingly. Based on fuzzy clustering of the intensity attributed to each point, different objects on the road surface are assigned different colors for representing abundant appearances. This unsupervised method is demonstrated in the experiment and shows great effectiveness in reconstructing and rendering better road surface.展开更多
In polar regions, cloud and underlying ice-snow areas are difficult to distinguish in satellite images because of their high albedo in the visible band and low surface temperature of ice-snow areas in the infrared ban...In polar regions, cloud and underlying ice-snow areas are difficult to distinguish in satellite images because of their high albedo in the visible band and low surface temperature of ice-snow areas in the infrared band. A cloud detection method over ice-snow covered areas in Antarctica is presented. On account of different texture features of cloud and ice-snow areas, five texture features are extracted based on GLCM. Nonlinear SVM is then used to obtain the optimal classification hyperplane from training data. The experiment results indicate that this algorithm performs well in cloud detection in Antarctica, especially for thin cirrus detection. Furthermore, when images are resampled to a quarter or 1/16 of the full size, cloud percentages are still at the same level, while the processing time decreases exponentially.展开更多
The Tan-Lu fault zone joins the Dabie Mountains on its eastern margin, and offsets the Dabie and Sulu orogenic belts sinistrally for about 500 kin. On the basis of calculation of temperature and pressure experienced b...The Tan-Lu fault zone joins the Dabie Mountains on its eastern margin, and offsets the Dabie and Sulu orogenic belts sinistrally for about 500 kin. On the basis of calculation of temperature and pressure experienced by the two phases of the fault zone as well as the thermo-chronological information on mylonite from the earlier and later Tan-Lu fault zones on the eastern margin of the Dabie Mountains, this paper discusses the delamination history and uplifting magnitudes of the Dabie Mountains from earlier Jurassic to earlier Cretaceous. From mineral assemblages, mineral deformation and muscovite-chlorite geothermometry calculation, it is known that the temperature experienced by the two phases of Tan-Lu fault zones are between 40℃ and 450℃, and the confining pressures are between 0.25Gpa and 0.36GPa for the earlier shear zones and 0.24-0.39GPa for the late shear zones. According to the geobarometry of Si-in-phengite and by considering shear heating and tectonic over-pressure, it is concluded that the maximum formation depths for the two phases of the ductile shear zones are not more than 12 kin. Differential formation depths for the two phases of shear zones are 1-2 km at most. At about 190 Ma and 128 Ma, the Tan-Lu fault zone experienced two phases of cooling events. During this period, the eastem margin of the Dabie Mountains experienced a tectonic calm period and no uplifting. According to information from the Tan-Lu fault zone, the uplifting magnitudes of the Dabie orogenic belts are not more than 12 km during the earlier Cretaceous.展开更多
In order to solve the problem of efficiently assigning tasks in an ad-hoc mobile cloud( AMC),a task assignment algorithm based on the heuristic algorithm is proposed. The proposed task assignment algorithm based on pa...In order to solve the problem of efficiently assigning tasks in an ad-hoc mobile cloud( AMC),a task assignment algorithm based on the heuristic algorithm is proposed. The proposed task assignment algorithm based on particle swarm optimization and simulated annealing( PSO-SA) transforms the dependencies between tasks into a directed acyclic graph( DAG) model. The number in each node represents the computation workload of each task and the number on each edge represents the workload produced by the transmission. In order to simulate the environment of task assignment in AMC,mathematical models are developed to describe the dependencies between tasks and the costs of each task are defined. PSO-SA is used to make the decision for task assignment and for minimizing the cost of all devices,which includes the energy consumption and time delay of all devices.PSO-SA also takes the advantage of both particle swarm optimization and simulated annealing by selecting an optimal solution with a certain probability to avoid falling into local optimal solution and to guarantee the convergence speed. The simulation results show that compared with other existing algorithms,the PSO-SA has a smaller cost and the result of PSO-SA can be very close to the optimal solution.展开更多
The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical c...The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical cumulative frequency above the tropopause （CTAT） are concentrated in three tropical regions：the Asian summer monsoon region,Central America,and western Africa.The contributions to the area-weighted CTAT frequency in the three regions from the Northern Hemisphere are 49.0%,13.5%,and 12.4%,respectively.Moreover,the contribution of troposphere-to-stratosphere transport （TST） in the Asian monsoon region to global TST can be far greater than 50%,according to analysis of the continuous equation,velocity potential,and divergent wind from ERA-Interim data.Furthermore,the Asian summer monsoon circulation system controls the distribution of the cloud top.On the south side of the Tibetan Plateau,the maximum frequency of the cloud top,more than 10% per 500 m vertically,is most likely to appear in the core of the high-level easterlyjet near the tropopause height （16.5 km）.Over the Tibetan Plateau,the maximum frequency of the cloud top,greater than 3% per 500 m vertically,is suppressed below 11 km,far away from the thermodynamic tropopause height but close to the dynamic tropopause height of 2 PVU （potential vorticity units）.展开更多
The shear wave splitting study is based on data of the 3 component digital seismograms. This was recorded at 3 sets of stations, which were set up after the Yaoan M S6 5 earthquake, near its epicenter. The results ind...The shear wave splitting study is based on data of the 3 component digital seismograms. This was recorded at 3 sets of stations, which were set up after the Yaoan M S6 5 earthquake, near its epicenter. The results indicate the following:①Shear wave splitting has been observed through analyzing 236 aftershock recordings within the shear wave window. ②The time delay was mostly in the range of 3 5～10 5ms/km and the average was 7 0ms/km.③The polarization direction of the fast split S wave was mostly in the range of N140°E～N164°E and the average was N152 4°E. ④The preferred polarization direction for the fast shear wave was different from the direction of the seismogenic structure of the mainshock (Maweijing fault) and the direction of the rupture of the aftershocks, but similar to the principal compressional axis of the regional stress field. ⑤Shear wave splitting for sequence of the aftershocks of the Yaoan earthquake was the result of anisotropy of EDA cracks controlled by stress field.展开更多
Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a provin...Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a province located in a low-latitude plateau,this work analyzes the climatic characteristics and the corresponding large-scale circulation patterns related to the western North Pacific westward moving TCs(WMTCs).Its impacts on the rainfall in the Yunnan Plateau are studied.Results show that WMTCs happen almost every year,mainly from July to September.It shows a downward trend in decadal variation.Nearly the entire Yunnan area is affected by them but the eastern part experiences the most severe influences.Most of the WMTCs migrate from the South China Sea,primarily make landfall in Hainan and Guangdong and enter the Northern Bay.The tracks of these typhoons can be classified into five categories,in which the most significant impact results from those making landfall in Guangdong.All categories of the tropical cyclones can induce province-wide heavy rainfall in Yunnan.Super typhoons bring about the heaviest and most extensive rainfall over the low-latitude plateau while the associated circulation pattern is marked with a dominant 500 hPa meridional circulation at middle latitudes,an active monsoon depression and Intertropical Convection Zone(ITCZ) at low latitudes and a westward-located South Asia High at 100 hPa,which is favorable for tropical cyclones to travel westward.WMTCs tend to go westward into the interior part of China if the subtropical high extends its westernmost ridge point to the northeast of Yunnan,or expands its periphery anti-cyclonic circulation to the Tibetan Plateau,or merges with the Qinghai-Tibetan high.展开更多
An M6.5 earthquake occurred on August 3rd, 2014 in Ludian of Yunnan Province in China, causing severe casualty and economic loss. Local broadband waveform inversion with the CAP method demonstrates that the earthquake...An M6.5 earthquake occurred on August 3rd, 2014 in Ludian of Yunnan Province in China, causing severe casualty and economic loss. Local broadband waveform inversion with the CAP method demonstrates that the earthquake is a strike-slip event, with the strike along 70° and 160° for the two nodal planes respectively. However, the geological structure in the epicentral region is complicated with abundant active faults, and it is challenging to identify the seismogenic fault with the focal plane solutions due to nodal-plane ambiguity. We resolved the rupture directivity by measuring the difference between centroid location and hypocenter of the Ludian earthquake with the time shift from CAP inversion, and found that the nodal plane with the strike of 160° is the ruptured fault plane. Moreover, the rupture is found to propagate from northwest to southeast.展开更多
In this work we compare the DNS results(Fabregat et al.2021,Fabregat et al.2021)for a mild cough already reported in the literarure with those obtained with a compressible URANS equations with a k-ϵturbulence model.In...In this work we compare the DNS results(Fabregat et al.2021,Fabregat et al.2021)for a mild cough already reported in the literarure with those obtained with a compressible URANS equations with a k-ϵturbulence model.In both cases,the dispersed phase has been modelled as spherical Lagrangian particles using the one-way coupling assumption.Overall,the URANS model is capable of reproducing the observed tendency of light particles under 64µm in diameter to rise due to the action of the drag exerted by the buoyant puff generated by the cough.Both DNS and URANS found that particles above 64µm will tend to describe parabolic trajectories under the action of gravitational forces.Grid independence analysis allows to qualify the impact of increasing mesh resolution on the particle cloud statistics as flow evolves.Results suggest that the k-ϵmodel overpredicts the horizontal displacement of the particles smaller than 64µm while the opposite occurs for the particles larger than 64µm.展开更多
文摘Based on the 3D electron's radial wave function of Co 2+ free ion,a Nephelauxetic effect modifying factor to modify the radial wave function is introduced when Co 2+ cations are put into the crystal field of Zn 1-x Co x Se.With the modified wave functions,the optical transitions for Zn 1-x Co x Se crystals are calculated.Moreover,based on the first principle of physics,the influences of high pressure to the Nephelauxetic effect modifying factor is considered,and the high pressure blue shift for the Zn 1-x Co x Se crystal absorption spectra are calculated and a shift rate of d E /d p =0 45meV/GPa is obtained.
基金Supported by the National Natural Science Foundation of China （No.40471089） and the Key Laboratory of Geo-informatics of State Bureau of Surveying and Mapping.
文摘A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of the road surface from noise is performed based on the fuzzy clustering of normal vectors, with which the mean value is calculated and the projecting plane of point cloud is created to obtain the geometric model accordingly. Based on fuzzy clustering of the intensity attributed to each point, different objects on the road surface are assigned different colors for representing abundant appearances. This unsupervised method is demonstrated in the experiment and shows great effectiveness in reconstructing and rendering better road surface.
基金Supported by the Antarctic Geography Information Acquisition and Environmental Change Research of China (No.14601402024-04-06).
文摘In polar regions, cloud and underlying ice-snow areas are difficult to distinguish in satellite images because of their high albedo in the visible band and low surface temperature of ice-snow areas in the infrared band. A cloud detection method over ice-snow covered areas in Antarctica is presented. On account of different texture features of cloud and ice-snow areas, five texture features are extracted based on GLCM. Nonlinear SVM is then used to obtain the optimal classification hyperplane from training data. The experiment results indicate that this algorithm performs well in cloud detection in Antarctica, especially for thin cirrus detection. Furthermore, when images are resampled to a quarter or 1/16 of the full size, cloud percentages are still at the same level, while the processing time decreases exponentially.
基金supported by the National Science Foundation ofChina(Grant No.40272094).
文摘The Tan-Lu fault zone joins the Dabie Mountains on its eastern margin, and offsets the Dabie and Sulu orogenic belts sinistrally for about 500 kin. On the basis of calculation of temperature and pressure experienced by the two phases of the fault zone as well as the thermo-chronological information on mylonite from the earlier and later Tan-Lu fault zones on the eastern margin of the Dabie Mountains, this paper discusses the delamination history and uplifting magnitudes of the Dabie Mountains from earlier Jurassic to earlier Cretaceous. From mineral assemblages, mineral deformation and muscovite-chlorite geothermometry calculation, it is known that the temperature experienced by the two phases of Tan-Lu fault zones are between 40℃ and 450℃, and the confining pressures are between 0.25Gpa and 0.36GPa for the earlier shear zones and 0.24-0.39GPa for the late shear zones. According to the geobarometry of Si-in-phengite and by considering shear heating and tectonic over-pressure, it is concluded that the maximum formation depths for the two phases of the ductile shear zones are not more than 12 kin. Differential formation depths for the two phases of shear zones are 1-2 km at most. At about 190 Ma and 128 Ma, the Tan-Lu fault zone experienced two phases of cooling events. During this period, the eastem margin of the Dabie Mountains experienced a tectonic calm period and no uplifting. According to information from the Tan-Lu fault zone, the uplifting magnitudes of the Dabie orogenic belts are not more than 12 km during the earlier Cretaceous.
基金The National Natural Science Foundation of China(No.61741102,61471164,61601122)the Fundamental Research Funds for the Central Universities(No.SJLX_160040)
文摘In order to solve the problem of efficiently assigning tasks in an ad-hoc mobile cloud( AMC),a task assignment algorithm based on the heuristic algorithm is proposed. The proposed task assignment algorithm based on particle swarm optimization and simulated annealing( PSO-SA) transforms the dependencies between tasks into a directed acyclic graph( DAG) model. The number in each node represents the computation workload of each task and the number on each edge represents the workload produced by the transmission. In order to simulate the environment of task assignment in AMC,mathematical models are developed to describe the dependencies between tasks and the costs of each task are defined. PSO-SA is used to make the decision for task assignment and for minimizing the cost of all devices,which includes the energy consumption and time delay of all devices.PSO-SA also takes the advantage of both particle swarm optimization and simulated annealing by selecting an optimal solution with a certain probability to avoid falling into local optimal solution and to guarantee the convergence speed. The simulation results show that compared with other existing algorithms,the PSO-SA has a smaller cost and the result of PSO-SA can be very close to the optimal solution.
基金supported by National Key Research and Development Program of China[grant number 2017YFC1501802]the National Natural Science Foundation of China[grant number 41375047],[grant number 91537213],and[grant number 41675039]
文摘The distribution characteristics of cloud-top and tropopause height in the tropics and subtropics in boreal summer are analyzed based on CALIPSO data for the period 2008-2012.The maximum values of cloud-top vertical cumulative frequency above the tropopause （CTAT） are concentrated in three tropical regions：the Asian summer monsoon region,Central America,and western Africa.The contributions to the area-weighted CTAT frequency in the three regions from the Northern Hemisphere are 49.0%,13.5%,and 12.4%,respectively.Moreover,the contribution of troposphere-to-stratosphere transport （TST） in the Asian monsoon region to global TST can be far greater than 50%,according to analysis of the continuous equation,velocity potential,and divergent wind from ERA-Interim data.Furthermore,the Asian summer monsoon circulation system controls the distribution of the cloud top.On the south side of the Tibetan Plateau,the maximum frequency of the cloud top,more than 10% per 500 m vertically,is most likely to appear in the core of the high-level easterlyjet near the tropopause height （16.5 km）.Over the Tibetan Plateau,the maximum frequency of the cloud top,greater than 3% per 500 m vertically,is suppressed below 11 km,far away from the thermodynamic tropopause height but close to the dynamic tropopause height of 2 PVU （potential vorticity units）.
文摘The shear wave splitting study is based on data of the 3 component digital seismograms. This was recorded at 3 sets of stations, which were set up after the Yaoan M S6 5 earthquake, near its epicenter. The results indicate the following:①Shear wave splitting has been observed through analyzing 236 aftershock recordings within the shear wave window. ②The time delay was mostly in the range of 3 5～10 5ms/km and the average was 7 0ms/km.③The polarization direction of the fast split S wave was mostly in the range of N140°E～N164°E and the average was N152 4°E. ④The preferred polarization direction for the fast shear wave was different from the direction of the seismogenic structure of the mainshock (Maweijing fault) and the direction of the rupture of the aftershocks, but similar to the principal compressional axis of the regional stress field. ⑤Shear wave splitting for sequence of the aftershocks of the Yaoan earthquake was the result of anisotropy of EDA cracks controlled by stress field.
基金Key National Project for Fundamental Research and Development (2009CB421504)National Science Foundation of China (40975032)Special Project for Forecasters in Yunnan Meteorological Bureau (YB200901)
文摘Using data available from the Retrieval System Based on Yearbooks of Tropical Cyclones over the Western North Pacific,NCEP/NCAR reanalysis daily data and observed precipitation data for 1959 to 2007 in Yunnan,a province located in a low-latitude plateau,this work analyzes the climatic characteristics and the corresponding large-scale circulation patterns related to the western North Pacific westward moving TCs(WMTCs).Its impacts on the rainfall in the Yunnan Plateau are studied.Results show that WMTCs happen almost every year,mainly from July to September.It shows a downward trend in decadal variation.Nearly the entire Yunnan area is affected by them but the eastern part experiences the most severe influences.Most of the WMTCs migrate from the South China Sea,primarily make landfall in Hainan and Guangdong and enter the Northern Bay.The tracks of these typhoons can be classified into five categories,in which the most significant impact results from those making landfall in Guangdong.All categories of the tropical cyclones can induce province-wide heavy rainfall in Yunnan.Super typhoons bring about the heaviest and most extensive rainfall over the low-latitude plateau while the associated circulation pattern is marked with a dominant 500 hPa meridional circulation at middle latitudes,an active monsoon depression and Intertropical Convection Zone(ITCZ) at low latitudes and a westward-located South Asia High at 100 hPa,which is favorable for tropical cyclones to travel westward.WMTCs tend to go westward into the interior part of China if the subtropical high extends its westernmost ridge point to the northeast of Yunnan,or expands its periphery anti-cyclonic circulation to the Tibetan Plateau,or merges with the Qinghai-Tibetan high.
基金supported by the National Natural Science Foundation of China(Grant No.41274069)National Basic Research Program of China(Grant No.2014CB845901)
文摘An M6.5 earthquake occurred on August 3rd, 2014 in Ludian of Yunnan Province in China, causing severe casualty and economic loss. Local broadband waveform inversion with the CAP method demonstrates that the earthquake is a strike-slip event, with the strike along 70° and 160° for the two nodal planes respectively. However, the geological structure in the epicentral region is complicated with abundant active faults, and it is challenging to identify the seismogenic fault with the focal plane solutions due to nodal-plane ambiguity. We resolved the rupture directivity by measuring the difference between centroid location and hypocenter of the Ludian earthquake with the time shift from CAP inversion, and found that the nodal plane with the strike of 160° is the ruptured fault plane. Moreover, the rupture is found to propagate from northwest to southeast.
基金This work was supported by Spanish Ministerio de Ciencia,Innovación y Universidades(Grants Nos.RTI2018-100907-A-I00 and PID2020-113303GB-C21)the Generalitat de Catalunya(Grant No.2017-SGR-1234).
文摘In this work we compare the DNS results(Fabregat et al.2021,Fabregat et al.2021)for a mild cough already reported in the literarure with those obtained with a compressible URANS equations with a k-ϵturbulence model.In both cases,the dispersed phase has been modelled as spherical Lagrangian particles using the one-way coupling assumption.Overall,the URANS model is capable of reproducing the observed tendency of light particles under 64µm in diameter to rise due to the action of the drag exerted by the buoyant puff generated by the cough.Both DNS and URANS found that particles above 64µm will tend to describe parabolic trajectories under the action of gravitational forces.Grid independence analysis allows to qualify the impact of increasing mesh resolution on the particle cloud statistics as flow evolves.Results suggest that the k-ϵmodel overpredicts the horizontal displacement of the particles smaller than 64µm while the opposite occurs for the particles larger than 64µm.
