Remote sensing has played a pivotal role in our understanding of the geometry of dykes and dyke swarms on Earth,Venus and Mars(West and Ernst,1991;Mege and Masson,1995;Ernst et al.,2005).Since the 1970’s
Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,f...Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,finer resolution and spatially continuous imper-vious areas information remains scarce in the Arctic.In this study,we developed an accurate and complete circumpolar Arctic Man-made impervious areas(CAMI)map at a resolution of 10 m by combining Sentinel-1 C-band Synthetic Aperture Radar,Sentinel-2 multispectral images,OpenStreetMap,and ArcticDEM via Google Earth Engine platform.A random forest classifier model was trained and used to generate corresponding impervious areas map for the year 2020.The evaluation results suggested that CAMI was the most accurate with an overall accuracy of 86.36%and kappa coefficient of 70.73%as against the three existing impervious areas products.Based on the generated map and OpenStreetMap,we estimated that total imper-vious areas area in the Arctic has achieved 807.80 km2,of which roads,industrial and resident land were three major land use types,accounting for 54.08%,17.85%and 10.34%,respectively.The CAMI map will support for new application and provide advanced insight into the infrastructure vulnerability evaluation and environmental sustainability in the Arctic.展开更多
Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus...Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus present a powerful tool to study the progressive changes of geological samples,and may even be applied to study extraterrestrial samples in search of life.One example we present here explore the use of elemental microprobe,X-Ray Photon Spectroscopy(XPS),and synchrotron-based Scanning Transmission X-ray Microscopy(STXM) coupled with Near Edge X-ray Absorption Fine Structure(NEXAFS) Spectroscopy to investigate the surface properties and stability of micron-size organic carbonaceous particles from Central Amazon,Brazil,specifically focusing on black carbon in Kaolinitic Oxisol originated from anthropogenic processes,and their interaction with cations.展开更多
Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of...Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of soil grid units at varying cell sizes was derived from soil polygon units at six map scales,namely,1:50 000(C5),1:200 000(D2),1:500 000(P5),1:1 000 000(N1),1:4 000 000(N4) and 1:14 000 000(N14),in the Taihu Region of China.Both soil unit formats were used for regional SOC pool simulation with a De Nitrification-DeC omposition(DNDC) process-based model,which spans the time period from 1982 to 2000 at the six map scales.Four indices,namely,soil type number(STN),area(AREA),average SOC density(ASOCD) and total SOC stocks(SOCS) of surface paddy soils that were simulated by the DNDC,were distinguished from all these soil polygon and grid units.Subjecting to the four index values(IV) from the parent polygon units,the variations in an index value(VIV,%) from the grid units were used to assess its dataset accuracy and redundancy,which reflects the uncertainty in the simulation of SOC pools.Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pools,matching their respective soil polygon unit map scales.With these optimal raster resolutions,the soil grid units datasets can have the same accuracy as their parent polygon units datasets without any redundancy,when VIV < 1% was assumed to be a criterion for all four indices.A quadratic curve regression model,namely,y = – 0.80 × 10^(–6)x^2 + 0.0228 x + 0.0211(R^2 = 0.9994,P < 0.05),and a power function model R? = 10.394?^(0.2153)(R^2 = 0.9759,P < 0.05) were revealed,which describe the relationship between the optimal soil grid unit resolution(y,km) and soil polygon unit map scale(1:10 000x),the ratio(R?,%) of the optimal soil grid size to average polygon patch size(?,km^2) and the ?,with the highest R^2 among different mathematical regressions,respectively.This knowledge may facilitate the grid partitioning of regions during the investigation and simulation of SOC pool dynamics at a certain map scale,and be referenced to other landscape polygon patches' mesh partition.展开更多
Academia has recently proposed new naming systems based on flat Distributed Hash Table （DHT）. These naming systems are designed to overcome defects--such as lack of support for data migration and replication--in the...Academia has recently proposed new naming systems based on flat Distributed Hash Table （DHT）. These naming systems are designed to overcome defects--such as lack of support for data migration and replication--in the Domain Name System （DNS）. DHT naming systems have long resolution delay and are not suitable for practical application. This paper introduces two new naming systems that have the advantages of both DNS and DHT systems. The first is a three-layer system based on one-hop DHT and is suitable for small-scale application. The second adopts a hybrid DHT structure, can be implemented in different domains, and can be applied globally. Theoretical analyses demonstrate that these two systems are feasible for practical use.展开更多
This Letter proposes a high bit-depth coding method to improve depth map resolution and render it suitable to human-eye observation in 3D range-intensity correlation laser imaging. In this method, a high bit-depth CCD...This Letter proposes a high bit-depth coding method to improve depth map resolution and render it suitable to human-eye observation in 3D range-intensity correlation laser imaging. In this method, a high bit-depth CCD camera with a nanosecond-sealed gated intensifier is used as an image sensor; subsequently two high bit-depth gate images with specific range-intensity profiles are obtained to establish the gray depth map and finally the gray depth map is encoded by an equidensity pseudocolor. With this method, a color depth map is generated with higher range resolution. In our experimental work, the range resolution of the depth map is improved by a factor of 1.67.展开更多
As the use of Cannabis products as natural medicines burgeons,it is also appearing as a food ingredient.It is important to screen Cannabis samples as ingredients by profiling their chemical compositions,which is refer...As the use of Cannabis products as natural medicines burgeons,it is also appearing as a food ingredient.It is important to screen Cannabis samples as ingredients by profiling their chemical compositions,which is referred to as chemotyping.Two sets of botanical extracts were studied.The first set is referred to as Cannabis contained plant materials from 15 samples of the sativa,indica,and hybrids of the two species.The second set contained 20 extracts from the variety of Cannabis sativa with low tetrahydrocannabinol(THC)concentrations,i.e.,below 0.3%,and,henceforth,will be referred to as hemp.An ultraviolet(UV)microplate reader provides a cost-effective and high-throughput method for identifying chemotypes of plant extracts by their spectra.The microplate reader affords rapid measurements of small volumes,e.g.,50μL,which demonstrates a potential to significantly reduce the analysis time and cost for Cannabis and hemp chemotyping or chemi-cal profiling.Replicate samples were measured on different days to demonstrate the robustness of the method.Projected difference resolution(PDR)maps were used to visualize the separations among the classes.Five multivariate classifiers,fuzzy rule-building expert system(FuRES),super partial least squares-discriminant analysis(sPLS-DA),support vector machine(SVM),and two tree-based support vector machines(SVMtreeG and SVMtreeH)were evaluated.The classifiers were validated with ten bootstrapped Latin partitions(BLPs).For the Cannabis extracts,the SVMtreeG yielded the best performance and the classification accuracy was 99.1±0.4%for spectra collected in the nonlinear absorbance range.For the hemp extracts,the SVM classifier performed the best with a 97.4±0.6%classification accuracy.These results demonstrate that the UV microplate reader coupled with multivariate classifiers can be used as a high-throughput and cost-effective approach for chemotyping Cannabis.展开更多
文摘Remote sensing has played a pivotal role in our understanding of the geometry of dykes and dyke swarms on Earth,Venus and Mars(West and Ernst,1991;Mege and Masson,1995;Ernst et al.,2005).Since the 1970’s
基金the National Key R&D Program of China[2018YFC1407103 and 2017YFA0604401]Annual Report(2022)on Remote Sensing Monitoring of Global Ecosystems and Environment[TC210E01B].
文摘Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,finer resolution and spatially continuous imper-vious areas information remains scarce in the Arctic.In this study,we developed an accurate and complete circumpolar Arctic Man-made impervious areas(CAMI)map at a resolution of 10 m by combining Sentinel-1 C-band Synthetic Aperture Radar,Sentinel-2 multispectral images,OpenStreetMap,and ArcticDEM via Google Earth Engine platform.A random forest classifier model was trained and used to generate corresponding impervious areas map for the year 2020.The evaluation results suggested that CAMI was the most accurate with an overall accuracy of 86.36%and kappa coefficient of 70.73%as against the three existing impervious areas products.Based on the generated map and OpenStreetMap,we estimated that total imper-vious areas area in the Arctic has achieved 807.80 km2,of which roads,industrial and resident land were three major land use types,accounting for 54.08%,17.85%and 10.34%,respectively.The CAMI map will support for new application and provide advanced insight into the infrastructure vulnerability evaluation and environmental sustainability in the Arctic.
文摘Nano-Scale mapping of minerals and organic compounds give unprecedented high resolution information on the origin and nature of substances,and provide new insight on their correlative distribution and interaction,thus present a powerful tool to study the progressive changes of geological samples,and may even be applied to study extraterrestrial samples in search of life.One example we present here explore the use of elemental microprobe,X-Ray Photon Spectroscopy(XPS),and synchrotron-based Scanning Transmission X-ray Microscopy(STXM) coupled with Near Edge X-ray Absorption Fine Structure(NEXAFS) Spectroscopy to investigate the surface properties and stability of micron-size organic carbonaceous particles from Central Amazon,Brazil,specifically focusing on black carbon in Kaolinitic Oxisol originated from anthropogenic processes,and their interaction with cations.
基金Under the auspices of Special Project of National Key Research and Development Program(No.2016YFD0200301)National Natural Science Foundation of China(No.41571206)Special Project of National Science and Technology Basic Work(No.2015FY110700-S2)
文摘Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of soil grid units at varying cell sizes was derived from soil polygon units at six map scales,namely,1:50 000(C5),1:200 000(D2),1:500 000(P5),1:1 000 000(N1),1:4 000 000(N4) and 1:14 000 000(N14),in the Taihu Region of China.Both soil unit formats were used for regional SOC pool simulation with a De Nitrification-DeC omposition(DNDC) process-based model,which spans the time period from 1982 to 2000 at the six map scales.Four indices,namely,soil type number(STN),area(AREA),average SOC density(ASOCD) and total SOC stocks(SOCS) of surface paddy soils that were simulated by the DNDC,were distinguished from all these soil polygon and grid units.Subjecting to the four index values(IV) from the parent polygon units,the variations in an index value(VIV,%) from the grid units were used to assess its dataset accuracy and redundancy,which reflects the uncertainty in the simulation of SOC pools.Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pools,matching their respective soil polygon unit map scales.With these optimal raster resolutions,the soil grid units datasets can have the same accuracy as their parent polygon units datasets without any redundancy,when VIV < 1% was assumed to be a criterion for all four indices.A quadratic curve regression model,namely,y = – 0.80 × 10^(–6)x^2 + 0.0228 x + 0.0211(R^2 = 0.9994,P < 0.05),and a power function model R? = 10.394?^(0.2153)(R^2 = 0.9759,P < 0.05) were revealed,which describe the relationship between the optimal soil grid unit resolution(y,km) and soil polygon unit map scale(1:10 000x),the ratio(R?,%) of the optimal soil grid size to average polygon patch size(?,km^2) and the ?,with the highest R^2 among different mathematical regressions,respectively.This knowledge may facilitate the grid partitioning of regions during the investigation and simulation of SOC pool dynamics at a certain map scale,and be referenced to other landscape polygon patches' mesh partition.
基金funded by the National Basic Research Program of China ("973"Program) under Grant No. 2007CB307100
文摘Academia has recently proposed new naming systems based on flat Distributed Hash Table （DHT）. These naming systems are designed to overcome defects--such as lack of support for data migration and replication--in the Domain Name System （DNS）. DHT naming systems have long resolution delay and are not suitable for practical application. This paper introduces two new naming systems that have the advantages of both DNS and DHT systems. The first is a three-layer system based on one-hop DHT and is suitable for small-scale application. The second adopts a hybrid DHT structure, can be implemented in different domains, and can be applied globally. Theoretical analyses demonstrate that these two systems are feasible for practical use.
基金supported by the National Natural Science Foundation of China under Grant Nos.61205019 and 61475150
文摘This Letter proposes a high bit-depth coding method to improve depth map resolution and render it suitable to human-eye observation in 3D range-intensity correlation laser imaging. In this method, a high bit-depth CCD camera with a nanosecond-sealed gated intensifier is used as an image sensor; subsequently two high bit-depth gate images with specific range-intensity profiles are obtained to establish the gray depth map and finally the gray depth map is encoded by an equidensity pseudocolor. With this method, a color depth map is generated with higher range resolution. In our experimental work, the range resolution of the depth map is improved by a factor of 1.67.
文摘As the use of Cannabis products as natural medicines burgeons,it is also appearing as a food ingredient.It is important to screen Cannabis samples as ingredients by profiling their chemical compositions,which is referred to as chemotyping.Two sets of botanical extracts were studied.The first set is referred to as Cannabis contained plant materials from 15 samples of the sativa,indica,and hybrids of the two species.The second set contained 20 extracts from the variety of Cannabis sativa with low tetrahydrocannabinol(THC)concentrations,i.e.,below 0.3%,and,henceforth,will be referred to as hemp.An ultraviolet(UV)microplate reader provides a cost-effective and high-throughput method for identifying chemotypes of plant extracts by their spectra.The microplate reader affords rapid measurements of small volumes,e.g.,50μL,which demonstrates a potential to significantly reduce the analysis time and cost for Cannabis and hemp chemotyping or chemi-cal profiling.Replicate samples were measured on different days to demonstrate the robustness of the method.Projected difference resolution(PDR)maps were used to visualize the separations among the classes.Five multivariate classifiers,fuzzy rule-building expert system(FuRES),super partial least squares-discriminant analysis(sPLS-DA),support vector machine(SVM),and two tree-based support vector machines(SVMtreeG and SVMtreeH)were evaluated.The classifiers were validated with ten bootstrapped Latin partitions(BLPs).For the Cannabis extracts,the SVMtreeG yielded the best performance and the classification accuracy was 99.1±0.4%for spectra collected in the nonlinear absorbance range.For the hemp extracts,the SVM classifier performed the best with a 97.4±0.6%classification accuracy.These results demonstrate that the UV microplate reader coupled with multivariate classifiers can be used as a high-throughput and cost-effective approach for chemotyping Cannabis.
