Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing...Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing adaptive optics system performance is the atmospheric refractive index structure constant,C_(n)^(2),which characterizes the intensity of atmospheric optical turbulence as a function of altitude.Given its simplicity,the lunar scintillometer is the preferred method for detecting atmospheric turbulence in challenging environments like Dome A in Antarctica,where sites are still in the developmental stages and local environmental conditions are extremely harsh.However,optimizing the performance of such instruments requires carefully determining the baseline configuration of photon sensors according to each site's specific optical turbulence profile characteristics.This study uses a Monte Carlo method to identify the optimal configuration for the KunLun Turbulence Profiler(KLTP),an instrument comparable to the lunar scintillometer,developed for use at Dome A.Simulations conducted using the obtained optimal baseline configuration recovered three different model optical turbulence profiles,demonstrating the effectiveness of our method in obtaining an optimal baseline configuration.Our approach can be easily applied to baseline design for similar turbulence profilers at other sites.展开更多
The county(city)located on the northern slope of the Kunlun Mountains is the primary area to solidify and extend the success of Xinjiang Uygur Autonomous Region,China in poverty alleviation.Its Sustainable Development...The county(city)located on the northern slope of the Kunlun Mountains is the primary area to solidify and extend the success of Xinjiang Uygur Autonomous Region,China in poverty alleviation.Its Sustainable Development Goals(SDGs)are intertwined with the concerted economic and social development of Xinjiang and the objective of achieving shared prosperity within the region.This study established a sustainable development evaluation framework by selecting 15 SDGs and 20 secondary indicators from the United Nations’SDGs.The aim of this study is to quantitatively assess the progress of SDGs at the county(city)level on the northern slope of the Kunlun Mountains.The results indicate that there are substantial variations in the scores of SDGs among the nine counties and one city located on the northern slope of the Kunlun Mountains.Notable high scores of SDGs are observed in the central and eastern regions,whereas lower scores are prevalent in the western areas.The scores of SDGs,in descending order,are as follows:62.22 for Minfeng County,54.22 for Hotan City,50.21 for Qiemo County,42.54 for Moyu County,41.56 for Ruoqiang County,41.39 for Qira County,39.86 for Lop County,38.25 for Yutian County,38.10 for Pishan County,and 36.87 for Hotan County.The performances of SDGs reveal that Hotan City,Lop County,Minfeng County,and Ruoqiang County have significant sustainable development capacity because they have three or more SDGs ranked as green color.However,Hotan County,Moyu County,Qira County,and Yutian County show the poorest performance,as they lack SDGs with green color.It is important to establish and enhance mechanisms that can ensure sustained income growth among poverty alleviation beneficiaries,sustained improvement in the capacity of rural governance,and the gradual improvement of social security system.These measures will facilitate the effective implementation of SDGs.Finally,this study offers a valuable support for governmental authorities and relevant departments in their decision-making processes.In addition,these results hold significant reference value for assessing SDGs at the county(city)level,particularly in areas characterized by low levels of economic development.展开更多
Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and c...Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and channels)of the catchment is assumed.This study focused on sediment connectivity analysis in the SlavíčRiver catchment in the MoravskoslezskéBeskydy Mts in the eastern part of the Czech Republic.The connectivity index and connectivity index target modelling were combined with an analysis of anthropogenic interventions.Additionally,field mapping,grain size of bed sediments and stream power analysis were used to obtain information about connectivity in the catchment.Based on the analysis and obtained results,terrain topography is the current main driving factor affecting the connectivity of sediment movement in the SlavíčRiver catchment.However,the modelling provided valuable information about high sediment connectivity despite different recent land use conditions(highly forested area of the catchment)than those in historical times from the 16th to 19th centuries when the SlavíčRiver catchment was highly deforested and sediment connectivity was probably higher.The analysis of anthropogenic interventions,field mapping,grain size of bed sediments and stream power analysis revealed more deceleration of sediment movement through the catchment,decreased sediment connectivity with bed erosion,and gradual river channel process transformation in some reaches.Field mapping has identified various natural formations and human-induced changes impacting the longitudinal and lateral connectivity in the SlavíčRiver.For instance,embankments along 48%of the river's length,both on the right and left banks,significantly hinder lateral sediment supply to the channel.Stream power index analysis indicates increased energy levels in the flowing water in the river's upper reaches(up to 404.8 W m^(-2)).This high energy is also observed in certain downstream sections(up to 337.6 W m^(-2)),where it is influenced by human activities.These conditions lead to intensified erosion processes,playing a crucial role in sediment connectivity.Similar observations were described in recent studies that pointed out the long-term human interventions on many streams draining European mountains,where a decrease in sediment connectivity in these streams is linked with sediment deficits and the transformation of processes forming channels.展开更多
针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算...针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算法。该算法根据无人驾驶车辆路径规划的相关理论,建立无人驾驶车辆路径规划问题的车辆运动学模型,为规划无人驾驶车辆最优、最高效、最安全路径提供理论依据。将上述算法在MATLAB上仿真,并在平均路径长度、平均路径规划时间、平均采样节点个数及节点利用率4个方面与基本RRT算法及MT-RRT算法进行了对比。仿真结果表明:5次多项式曲线与MT-RRT算法的融合算法具有最高的性能,可以规划出最优路径。展开更多
Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about...Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about the uplift of the plateau was similar to the first one in tectonic theory, but they consider the time of C3 plant change to C4 in the South Asia, as the time when the plateau reached its highest elevation. This time is 8Ma BP. The third idea, the most Chinese scientists believed, the nearest uplift of the plateau took place since 3 4Ma BP. The occurrence of fault depression and gravel deposit with large thickness in the inner and the marge of the plateau represented the speed uplift. After the collision of the India plate and the Eurasia plateau by the 36Ma, the Tibetean area uplifted several times, but it had been planed to lower area. The plateau with 4500m elevation formed in the Quaternary. While our recent research in the Kunlun Pass area suggest , the nearest uplift occurred at the border of the Early and Middle Pleistocene, and before that time, the elevation of this area was no more than 1500 m.展开更多
The early aged ophiolites have attracted attention of many geologists in recent decades, because the early aged ophiolites can provide the information about the ancient oceanic processes relevant to the evolution of p...The early aged ophiolites have attracted attention of many geologists in recent decades, because the early aged ophiolites can provide the information about the ancient oceanic processes relevant to the evolution of plate tectonics in the early period of the earth, and also concern such problems as whether there existed a "Proto-Tethys" and the break-up and convergence of the Rodinian Supercontinent. This paper reveals a definite complete ophiolite of Neoproterozoic-Early Paleozoic, named Kuda ophiolite in the western Kunlun Mrs., NW Tibetan Plateau, and reports the recent reasonable SHRIMP zircon U-Pb ages of 510±4 Ma, and 502±13 Ma for the cumulates of the Kuda ophiolite, using the most powerful dating tool, the SHRIMP-Ⅱ. The geochemical and geochronology data integrating with the geological setting suggest that the Kuda ophiolite might have formed in an archipelago oceanic basin, not in a vast ocean, the so-called "Proto-Tethys", and was tectonically emplaced during the Early Paleozoic.展开更多
The Tarim basin, located in the northern margin of Tibet, plays a key role in comprehending Tibetan plateau rapid uplift process. Focuses have been on the contribution of basin block to create high mountain (e.g.,Chen...The Tarim basin, located in the northern margin of Tibet, plays a key role in comprehending Tibetan plateau rapid uplift process. Focuses have been on the contribution of basin block to create high mountain (e.g.,Chen and Molnar,1977, Molnar et al.,1993, Ph. Matte, Tapponnier et al.,1996) since 1970. The models, which mainly depend on result of geological survey and other geophysical observation in the region excepted Deep Seismic Sounding, remained unsure because of blank(or absence ) of DSS data until our experiment was performed. How Tarim and west Kunlun to contact in depth ? What different is in crust structure between Tarim and west Kunlun Mt.? This is what we will reply to in our program.We finished the program in 1997. A total of 120 set seismograms (with 3\|component sensors) and 18000kg (AT and TNT) dynamos were used for the DSS field project. 6 shot in Tarim basin and 1 shot in west Kunlun Mt. (Quanshuigou) had been shoot successfully. One shot (Pishan shot) is used as fan\|shape observation (offset is from 150km to 220km) in 6 shots located in Tarim basin. The survey line is along Hotan river across the Tarim basin from the north to the south. In particular, we carried 20 set seismic recorders to Kunlun Mt. to make a short line about 60 km as the southern tendency of our line. The seismic recorders were placed in an interval of 3km from one stations to the next and covered a distance of more than 300km. The stations have to be moved their location per 2\|shotting to form a meeting system or a tracing system (layout). Fig.1 showed our survey line and location of shot as well as recorder stations. Finally we gained 625 cassettes with original seismic record (include cassettes of shooting time recorder et al.). After data process total 1147 quite high\|quality three\|component digital records have been used to analyze. Here, only results of analyzing P wave data is given.展开更多
1.Objective The West Kunlun in Xinjiang is located on the northwestern margin of the Qinghai-Tibet Plateau(Fig.1a)and at the junction of the Paleo-Asian tectonic domain and the Tethys tectonic domain.It serves as an i...1.Objective The West Kunlun in Xinjiang is located on the northwestern margin of the Qinghai-Tibet Plateau(Fig.1a)and at the junction of the Paleo-Asian tectonic domain and the Tethys tectonic domain.It serves as an important area for the study on the geologic evolution of the Karakorum-West Kunlun due to its special tectonic position.展开更多
基金financially supported by the National Natural Science Foundation of China (12373092, 12273027, 11733007, 11873010, 12133010)the Nebula Talents Program of the National Astronomical Observatories, CAS+1 种基金the Sichuan Youth Science and Technology Innovation Research Team (21CXTD0038)the Innovation Team F unds of China West Normal University (KCXTD2022-6).
文摘Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing adaptive optics system performance is the atmospheric refractive index structure constant,C_(n)^(2),which characterizes the intensity of atmospheric optical turbulence as a function of altitude.Given its simplicity,the lunar scintillometer is the preferred method for detecting atmospheric turbulence in challenging environments like Dome A in Antarctica,where sites are still in the developmental stages and local environmental conditions are extremely harsh.However,optimizing the performance of such instruments requires carefully determining the baseline configuration of photon sensors according to each site's specific optical turbulence profile characteristics.This study uses a Monte Carlo method to identify the optimal configuration for the KunLun Turbulence Profiler(KLTP),an instrument comparable to the lunar scintillometer,developed for use at Dome A.Simulations conducted using the obtained optimal baseline configuration recovered three different model optical turbulence profiles,demonstrating the effectiveness of our method in obtaining an optimal baseline configuration.Our approach can be easily applied to baseline design for similar turbulence profilers at other sites.
基金financially supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region,China(2022D01B234).
文摘The county(city)located on the northern slope of the Kunlun Mountains is the primary area to solidify and extend the success of Xinjiang Uygur Autonomous Region,China in poverty alleviation.Its Sustainable Development Goals(SDGs)are intertwined with the concerted economic and social development of Xinjiang and the objective of achieving shared prosperity within the region.This study established a sustainable development evaluation framework by selecting 15 SDGs and 20 secondary indicators from the United Nations’SDGs.The aim of this study is to quantitatively assess the progress of SDGs at the county(city)level on the northern slope of the Kunlun Mountains.The results indicate that there are substantial variations in the scores of SDGs among the nine counties and one city located on the northern slope of the Kunlun Mountains.Notable high scores of SDGs are observed in the central and eastern regions,whereas lower scores are prevalent in the western areas.The scores of SDGs,in descending order,are as follows:62.22 for Minfeng County,54.22 for Hotan City,50.21 for Qiemo County,42.54 for Moyu County,41.56 for Ruoqiang County,41.39 for Qira County,39.86 for Lop County,38.25 for Yutian County,38.10 for Pishan County,and 36.87 for Hotan County.The performances of SDGs reveal that Hotan City,Lop County,Minfeng County,and Ruoqiang County have significant sustainable development capacity because they have three or more SDGs ranked as green color.However,Hotan County,Moyu County,Qira County,and Yutian County show the poorest performance,as they lack SDGs with green color.It is important to establish and enhance mechanisms that can ensure sustained income growth among poverty alleviation beneficiaries,sustained improvement in the capacity of rural governance,and the gradual improvement of social security system.These measures will facilitate the effective implementation of SDGs.Finally,this study offers a valuable support for governmental authorities and relevant departments in their decision-making processes.In addition,these results hold significant reference value for assessing SDGs at the county(city)level,particularly in areas characterized by low levels of economic development.
基金supported by an internal grant of the University of Ostrava[SGS10/PřF/2021-Specificity of fluvial landscape in the context of historical and future changes].
文摘Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and channels)of the catchment is assumed.This study focused on sediment connectivity analysis in the SlavíčRiver catchment in the MoravskoslezskéBeskydy Mts in the eastern part of the Czech Republic.The connectivity index and connectivity index target modelling were combined with an analysis of anthropogenic interventions.Additionally,field mapping,grain size of bed sediments and stream power analysis were used to obtain information about connectivity in the catchment.Based on the analysis and obtained results,terrain topography is the current main driving factor affecting the connectivity of sediment movement in the SlavíčRiver catchment.However,the modelling provided valuable information about high sediment connectivity despite different recent land use conditions(highly forested area of the catchment)than those in historical times from the 16th to 19th centuries when the SlavíčRiver catchment was highly deforested and sediment connectivity was probably higher.The analysis of anthropogenic interventions,field mapping,grain size of bed sediments and stream power analysis revealed more deceleration of sediment movement through the catchment,decreased sediment connectivity with bed erosion,and gradual river channel process transformation in some reaches.Field mapping has identified various natural formations and human-induced changes impacting the longitudinal and lateral connectivity in the SlavíčRiver.For instance,embankments along 48%of the river's length,both on the right and left banks,significantly hinder lateral sediment supply to the channel.Stream power index analysis indicates increased energy levels in the flowing water in the river's upper reaches(up to 404.8 W m^(-2)).This high energy is also observed in certain downstream sections(up to 337.6 W m^(-2)),where it is influenced by human activities.These conditions lead to intensified erosion processes,playing a crucial role in sediment connectivity.Similar observations were described in recent studies that pointed out the long-term human interventions on many streams draining European mountains,where a decrease in sediment connectivity in these streams is linked with sediment deficits and the transformation of processes forming channels.
文摘针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算法。该算法根据无人驾驶车辆路径规划的相关理论,建立无人驾驶车辆路径规划问题的车辆运动学模型,为规划无人驾驶车辆最优、最高效、最安全路径提供理论依据。将上述算法在MATLAB上仿真,并在平均路径长度、平均路径规划时间、平均采样节点个数及节点利用率4个方面与基本RRT算法及MT-RRT算法进行了对比。仿真结果表明:5次多项式曲线与MT-RRT算法的融合算法具有最高的性能,可以规划出最优路径。
文摘Introduction There are big disputes on the uplift of the Tibetan Plateau. Some scientists believe the plateau uplifted to its highest elevation by 14Ma BP,and it decreased in elevation afterward. The second idea about the uplift of the plateau was similar to the first one in tectonic theory, but they consider the time of C3 plant change to C4 in the South Asia, as the time when the plateau reached its highest elevation. This time is 8Ma BP. The third idea, the most Chinese scientists believed, the nearest uplift of the plateau took place since 3 4Ma BP. The occurrence of fault depression and gravel deposit with large thickness in the inner and the marge of the plateau represented the speed uplift. After the collision of the India plate and the Eurasia plateau by the 36Ma, the Tibetean area uplifted several times, but it had been planed to lower area. The plateau with 4500m elevation formed in the Quaternary. While our recent research in the Kunlun Pass area suggest , the nearest uplift occurred at the border of the Early and Middle Pleistocene, and before that time, the elevation of this area was no more than 1500 m.
基金This research is financially supported by China Geological Survey(Project No.2003 13000059)the Department of International Cooperation and Science and Technology,Ministry of Land and Resources(Project No.2001010205)the key project of the Ministry of Science and Technology(MOST)(Project No.2001CB711001).
文摘The early aged ophiolites have attracted attention of many geologists in recent decades, because the early aged ophiolites can provide the information about the ancient oceanic processes relevant to the evolution of plate tectonics in the early period of the earth, and also concern such problems as whether there existed a "Proto-Tethys" and the break-up and convergence of the Rodinian Supercontinent. This paper reveals a definite complete ophiolite of Neoproterozoic-Early Paleozoic, named Kuda ophiolite in the western Kunlun Mrs., NW Tibetan Plateau, and reports the recent reasonable SHRIMP zircon U-Pb ages of 510±4 Ma, and 502±13 Ma for the cumulates of the Kuda ophiolite, using the most powerful dating tool, the SHRIMP-Ⅱ. The geochemical and geochronology data integrating with the geological setting suggest that the Kuda ophiolite might have formed in an archipelago oceanic basin, not in a vast ocean, the so-called "Proto-Tethys", and was tectonically emplaced during the Early Paleozoic.
文摘The Tarim basin, located in the northern margin of Tibet, plays a key role in comprehending Tibetan plateau rapid uplift process. Focuses have been on the contribution of basin block to create high mountain (e.g.,Chen and Molnar,1977, Molnar et al.,1993, Ph. Matte, Tapponnier et al.,1996) since 1970. The models, which mainly depend on result of geological survey and other geophysical observation in the region excepted Deep Seismic Sounding, remained unsure because of blank(or absence ) of DSS data until our experiment was performed. How Tarim and west Kunlun to contact in depth ? What different is in crust structure between Tarim and west Kunlun Mt.? This is what we will reply to in our program.We finished the program in 1997. A total of 120 set seismograms (with 3\|component sensors) and 18000kg (AT and TNT) dynamos were used for the DSS field project. 6 shot in Tarim basin and 1 shot in west Kunlun Mt. (Quanshuigou) had been shoot successfully. One shot (Pishan shot) is used as fan\|shape observation (offset is from 150km to 220km) in 6 shots located in Tarim basin. The survey line is along Hotan river across the Tarim basin from the north to the south. In particular, we carried 20 set seismic recorders to Kunlun Mt. to make a short line about 60 km as the southern tendency of our line. The seismic recorders were placed in an interval of 3km from one stations to the next and covered a distance of more than 300km. The stations have to be moved their location per 2\|shotting to form a meeting system or a tracing system (layout). Fig.1 showed our survey line and location of shot as well as recorder stations. Finally we gained 625 cassettes with original seismic record (include cassettes of shooting time recorder et al.). After data process total 1147 quite high\|quality three\|component digital records have been used to analyze. Here, only results of analyzing P wave data is given.
基金supported by the National Science Foundation of China(41302051)the Natural Science Foundation of Shaanxi Province(2020JM-311)the project of China Geological Survey(DD20221636,DD20221691)。
文摘1.Objective The West Kunlun in Xinjiang is located on the northwestern margin of the Qinghai-Tibet Plateau(Fig.1a)and at the junction of the Paleo-Asian tectonic domain and the Tethys tectonic domain.It serves as an important area for the study on the geologic evolution of the Karakorum-West Kunlun due to its special tectonic position.