This review describes the history of taxonomic research on scorpions and provides an updated checklist and key of the scorpions currently known in China. This checklist is based on a thorough review of the extant lite...This review describes the history of taxonomic research on scorpions and provides an updated checklist and key of the scorpions currently known in China. This checklist is based on a thorough review of the extant literatures on scorpion species whose presence has been confirmed in China through field expeditions and examination of scorpion collections, excepting a few members that have no clear distribution or are currently in doubt. Totally, the scorpion fauna of China consists of 53 species and subspecies belonging to 12 genera crossing five families, with 33 species(62.3%) and one genus being recorded as endemic. Additionally, identification key and the distribution of scorpions from China are provided.展开更多
Infrared metamaterial absorber(MMA) based on metal-insulator-metal(MIM) configuration with flexible design,perfect and selective absorption,has attracted much attention recently for passive radiative cooling applicati...Infrared metamaterial absorber(MMA) based on metal-insulator-metal(MIM) configuration with flexible design,perfect and selective absorption,has attracted much attention recently for passive radiative cooling applications.To cool objects passively,broadband infrared absorption(i.e.8-14 μm) is desirable to emit thermal energy through atmosphere window.We present a novel MMA composed of multilayer MIM resonators periodically arranged on a PbTe/MgF_(2) bilayer substrate.Verified by the rigorous coup led-wave analysis method,the proposed MMA shows a relative bandwidth of about 45%(from 8.3 to 13.1 μm with the absorption intensity over 0.8).The broadband absorption performs stably over a wide incident angle range(below 50°) and predicts 12 K cooling below ambient temperature at nighttime.Compared with the previous passive radiative coolers,our design gets rid of the continuous metal substrate and provides an almost ideal transparency window(close to 100%)for millimeter waves over 1 mm.The structure is expected to have potential applications in thermal control of integrated devices,where millimeter wave signal compatibility is also required.展开更多
The abundance of domesticated sheep varieties and phenotypes is largely the result of long-term natural and artificial selection. However, there is limited information regarding the genetic mechanisms underlying pheno...The abundance of domesticated sheep varieties and phenotypes is largely the result of long-term natural and artificial selection. However, there is limited information regarding the genetic mechanisms underlying phenotypic variation induced by the domestication and improvement of sheep. In this study, to explore genomic diversity and selective regions at the genome level, we sequenced the genomes of 100 sheep across 10 breeds and combined these results with publicly available genomic data from 225 individuals, including improved breeds, Chinese indigenous breeds,African indigenous breeds, and their Asian mouflon ancestor. Based on population structure, the domesticated sheep formed a monophyletic group,while the Chinese indigenous sheep showed a clear geographical distribution trend. Comparative genomic analysis of domestication identified several selective signatures, including IFI44 and IFI44L genes and PANK2 and RNF24 genes, associated with immune response and visual function.Population genomic analysis of improvement demonstrated that candidate genes of selected regions were mainly associated with pigmentation,energy metabolism, and growth development.Furthermore, the IFI44 and IFI44L genes showed a common selection signature in the genomes of 30domesticated sheep breeds. The IFI44 c. 54413058C>G mutation was selected for genotyping and population genetic validation. Results showed that the IFI44 polymorphism was significantly associated with partial immune traits. Our findings identified the population genetic basis of domesticated sheep at the whole-genome level, providing theoretical insights into the molecular mechanism underlying breed characteristics and phenotypic changes during sheep domestication and improvement.展开更多
Tracking registration is a key issue in augmented reality applications,particularly where there are no artificial identifier placed manually.In this paper,an efficient markerless tracking registration algorithm which ...Tracking registration is a key issue in augmented reality applications,particularly where there are no artificial identifier placed manually.In this paper,an efficient markerless tracking registration algorithm which combines the detector and the tracker is presented for the augmented reality system.We capture the target images in real scenes as template images,use the random ferns classifier for target detection and solve the problem of reinitialization after tracking registration failures due to changes in ambient lighting or occlusion of targets.Once the target has been successfully detected,the pyramid Lucas-Kanade(LK)optical flow tracker is used to track the detected target in real time to solve the problem of slow speed.The least median of squares(LMedS)method is used to adaptively calculate the homography matrix,and then the three-dimensional pose is estimated and the virtual object is rendered and registered.Experimental results demonstrate that the algorithm is more accurate,faster and more robust.展开更多
In order to overcome the defects where the surface of the object lacks sufficient texture features and the algorithm cannot meet the real-time requirements of augmented reality,a markerless augmented reality tracking ...In order to overcome the defects where the surface of the object lacks sufficient texture features and the algorithm cannot meet the real-time requirements of augmented reality,a markerless augmented reality tracking registration method based on multimodal template matching and point clouds is proposed.The method first adapts the linear parallel multi-modal LineMod template matching method with scale invariance to identify the texture-less target and obtain the reference image as the key frame that is most similar to the current perspective.Then,we can obtain the initial pose of the camera and solve the problem of re-initialization because of tracking registration interruption.A point cloud-based method is used to calculate the precise pose of the camera in real time.In order to solve the problem that the traditional iterative closest point(ICP)algorithm cannot meet the real-time requirements of the system,Kdtree(k-dimensional tree)is used under the graphics processing unit(GPU)to replace the part of finding the nearest points in the original ICP algorithm to improve the speed of tracking registration.At the same time,the random sample consensus(RANSAC)algorithm is used to remove the error point pairs to improve the accuracy of the algorithm.The results show that the proposed tracking registration method has good real-time performance and robustness.展开更多
The graph-based manifold ranking saliency detection only relies on the boundary background to extract foreground seeds,resulting in a poor saliency detection result,so a method that obtains robust foreground for manif...The graph-based manifold ranking saliency detection only relies on the boundary background to extract foreground seeds,resulting in a poor saliency detection result,so a method that obtains robust foreground for manifold ranking is proposed in this paper.First,boundary connectivity is used to select the boundary background for manifold ranking to get a preliminary saliency map,and a foreground region is acquired by a binary segmentation of the map.Second,the feature points of the original image and the filtered image are obtained by using color boosting Harris corners to generate two different convex hulls.Calculating the intersection of these two convex hulls,a final convex hull is found.Finally,the foreground region and the final convex hull are combined to extract robust foreground seeds for manifold ranking and getting final saliency map.Experimental results on two public image datasets show that the proposed method gains improved performance compared with some other classic methods in three evaluation indicators:precision-recall curve,F-measure and mean absolute error.展开更多
In order to improve the low positioning accuracy and execution efficiency of the robot binocular vision,a binocular vision positioning method based on coarse-fine stereo matching is proposed to achieve object position...In order to improve the low positioning accuracy and execution efficiency of the robot binocular vision,a binocular vision positioning method based on coarse-fine stereo matching is proposed to achieve object positioning.The random fern is used in the coarse matching to identify objects in the left and right images,and the pixel coordinates of the object center points in the two images are calculated to complete the center matching.In the fine matching,the right center point is viewed as an estimated value to set the search range of the right image,in which the region matching is implemented to find the best matched point of the left center point.Then,the similar triangle principle of the binocular vision model is used to calculate the 3D coordinates of the center point,achieving fast and accurate object positioning.Finally,the proposed method is applied to the object scene images and the robotic arm grasping platform.The experimental results show that the average absolute positioning error and average relative positioning error of the proposed method are 8.22 mm and 1.96%respectively when the object's depth distance is within 600 mm,the time consumption is less than 1.029s.The method can meet the needs of the robot grasping system,and has better accuracy and robustness.展开更多
基金supported by grants from the National Natural Sciences Foundation of China(31071942)the Basic Project of Ministry of Science and Technology of China(2007FY210800)the 973 program(2010CB529800)
文摘This review describes the history of taxonomic research on scorpions and provides an updated checklist and key of the scorpions currently known in China. This checklist is based on a thorough review of the extant literatures on scorpion species whose presence has been confirmed in China through field expeditions and examination of scorpion collections, excepting a few members that have no clear distribution or are currently in doubt. Totally, the scorpion fauna of China consists of 53 species and subspecies belonging to 12 genera crossing five families, with 33 species(62.3%) and one genus being recorded as endemic. Additionally, identification key and the distribution of scorpions from China are provided.
基金Supported by the National Natural Science Foundation of China(Grant Nos.52022018 and 52021001)the Program for Changjiang Scholars and Innovative Research Team in University。
文摘Infrared metamaterial absorber(MMA) based on metal-insulator-metal(MIM) configuration with flexible design,perfect and selective absorption,has attracted much attention recently for passive radiative cooling applications.To cool objects passively,broadband infrared absorption(i.e.8-14 μm) is desirable to emit thermal energy through atmosphere window.We present a novel MMA composed of multilayer MIM resonators periodically arranged on a PbTe/MgF_(2) bilayer substrate.Verified by the rigorous coup led-wave analysis method,the proposed MMA shows a relative bandwidth of about 45%(from 8.3 to 13.1 μm with the absorption intensity over 0.8).The broadband absorption performs stably over a wide incident angle range(below 50°) and predicts 12 K cooling below ambient temperature at nighttime.Compared with the previous passive radiative coolers,our design gets rid of the continuous metal substrate and provides an almost ideal transparency window(close to 100%)for millimeter waves over 1 mm.The structure is expected to have potential applications in thermal control of integrated devices,where millimeter wave signal compatibility is also required.
基金supported by the National Key R&D Program of China (2021YFD1300901)National Natural Science Foundation of China (31960653)+1 种基金West Light Foundation of the Chinese Academy of SciencesNational Joint Research on Improved Breeds of Livestock and Poultry (19210365)。
文摘The abundance of domesticated sheep varieties and phenotypes is largely the result of long-term natural and artificial selection. However, there is limited information regarding the genetic mechanisms underlying phenotypic variation induced by the domestication and improvement of sheep. In this study, to explore genomic diversity and selective regions at the genome level, we sequenced the genomes of 100 sheep across 10 breeds and combined these results with publicly available genomic data from 225 individuals, including improved breeds, Chinese indigenous breeds,African indigenous breeds, and their Asian mouflon ancestor. Based on population structure, the domesticated sheep formed a monophyletic group,while the Chinese indigenous sheep showed a clear geographical distribution trend. Comparative genomic analysis of domestication identified several selective signatures, including IFI44 and IFI44L genes and PANK2 and RNF24 genes, associated with immune response and visual function.Population genomic analysis of improvement demonstrated that candidate genes of selected regions were mainly associated with pigmentation,energy metabolism, and growth development.Furthermore, the IFI44 and IFI44L genes showed a common selection signature in the genomes of 30domesticated sheep breeds. The IFI44 c. 54413058C>G mutation was selected for genotyping and population genetic validation. Results showed that the IFI44 polymorphism was significantly associated with partial immune traits. Our findings identified the population genetic basis of domesticated sheep at the whole-genome level, providing theoretical insights into the molecular mechanism underlying breed characteristics and phenotypic changes during sheep domestication and improvement.
基金supported by National Natural Science Foundation of China(No.61125101).
文摘Tracking registration is a key issue in augmented reality applications,particularly where there are no artificial identifier placed manually.In this paper,an efficient markerless tracking registration algorithm which combines the detector and the tracker is presented for the augmented reality system.We capture the target images in real scenes as template images,use the random ferns classifier for target detection and solve the problem of reinitialization after tracking registration failures due to changes in ambient lighting or occlusion of targets.Once the target has been successfully detected,the pyramid Lucas-Kanade(LK)optical flow tracker is used to track the detected target in real time to solve the problem of slow speed.The least median of squares(LMedS)method is used to adaptively calculate the homography matrix,and then the three-dimensional pose is estimated and the virtual object is rendered and registered.Experimental results demonstrate that the algorithm is more accurate,faster and more robust.
基金This work was supported by National Natural Science Foundation of China(No.61125101).
文摘In order to overcome the defects where the surface of the object lacks sufficient texture features and the algorithm cannot meet the real-time requirements of augmented reality,a markerless augmented reality tracking registration method based on multimodal template matching and point clouds is proposed.The method first adapts the linear parallel multi-modal LineMod template matching method with scale invariance to identify the texture-less target and obtain the reference image as the key frame that is most similar to the current perspective.Then,we can obtain the initial pose of the camera and solve the problem of re-initialization because of tracking registration interruption.A point cloud-based method is used to calculate the precise pose of the camera in real time.In order to solve the problem that the traditional iterative closest point(ICP)algorithm cannot meet the real-time requirements of the system,Kdtree(k-dimensional tree)is used under the graphics processing unit(GPU)to replace the part of finding the nearest points in the original ICP algorithm to improve the speed of tracking registration.At the same time,the random sample consensus(RANSAC)algorithm is used to remove the error point pairs to improve the accuracy of the algorithm.The results show that the proposed tracking registration method has good real-time performance and robustness.
文摘The graph-based manifold ranking saliency detection only relies on the boundary background to extract foreground seeds,resulting in a poor saliency detection result,so a method that obtains robust foreground for manifold ranking is proposed in this paper.First,boundary connectivity is used to select the boundary background for manifold ranking to get a preliminary saliency map,and a foreground region is acquired by a binary segmentation of the map.Second,the feature points of the original image and the filtered image are obtained by using color boosting Harris corners to generate two different convex hulls.Calculating the intersection of these two convex hulls,a final convex hull is found.Finally,the foreground region and the final convex hull are combined to extract robust foreground seeds for manifold ranking and getting final saliency map.Experimental results on two public image datasets show that the proposed method gains improved performance compared with some other classic methods in three evaluation indicators:precision-recall curve,F-measure and mean absolute error.
基金Project supported by the Zhejiang Medical and Health Science and Technology Project(Nos.2017KY005,2019KY017, 2018KY868)the Key Projects Jointly Constructed by the Ministry and the Province of Zhejiang Medical and Health Science and Technology Project(No.WKJ-ZJ-2019)the Key and Major Projects of Traditional Chinese Medicine Scientific Research Foundation of Zhejiang Province(Nos.2019ZZ001 , 2018ZY001),China。
基金supported by National Natural Science Foundation of China(No.61125101)。
文摘In order to improve the low positioning accuracy and execution efficiency of the robot binocular vision,a binocular vision positioning method based on coarse-fine stereo matching is proposed to achieve object positioning.The random fern is used in the coarse matching to identify objects in the left and right images,and the pixel coordinates of the object center points in the two images are calculated to complete the center matching.In the fine matching,the right center point is viewed as an estimated value to set the search range of the right image,in which the region matching is implemented to find the best matched point of the left center point.Then,the similar triangle principle of the binocular vision model is used to calculate the 3D coordinates of the center point,achieving fast and accurate object positioning.Finally,the proposed method is applied to the object scene images and the robotic arm grasping platform.The experimental results show that the average absolute positioning error and average relative positioning error of the proposed method are 8.22 mm and 1.96%respectively when the object's depth distance is within 600 mm,the time consumption is less than 1.029s.The method can meet the needs of the robot grasping system,and has better accuracy and robustness.
