In order to solve the problem of small objects detection in unmanned aerial vehicle(UAV)aerial images with complex background,a general detection method for multi-scale small objects based on Faster region-based convo...In order to solve the problem of small objects detection in unmanned aerial vehicle(UAV)aerial images with complex background,a general detection method for multi-scale small objects based on Faster region-based convolutional neural network(Faster R-CNN)is proposed.The bird’s nest on the high-voltage tower is taken as the research object.Firstly,we use the improved convolutional neural network ResNet101 to extract object features,and then use multi-scale sliding windows to obtain the object region proposals on the convolution feature maps with different resolutions.Finally,a deconvolution operation is added to further enhance the selected feature map with higher resolution,and then it taken as a feature mapping layer of the region proposals passing to the object detection sub-network.The detection results of the bird’s nest in UAV aerial images show that the proposed method can precisely detect small objects in aerial images.展开更多
China’s first Mars exploration mission is scheduled to be launched in 2020.It aims not only to conduct global and comprehensive exploration of Mars by use of an orbiter but also to carry out in situ observation of ke...China’s first Mars exploration mission is scheduled to be launched in 2020.It aims not only to conduct global and comprehensive exploration of Mars by use of an orbiter but also to carry out in situ observation of key sites on Mars with a rover.This mission focuses on the following studies:topography,geomorphology,geological structure,soil characteristics,water-ice distribution,material composition,atmosphere and ionosphere,surface climate,environmental characteristics,Mars internal structure,and Martian magnetic field.It is comprised of an orbiter,a lander,and a rover equipped with 13 scientific payloads.This article will give an introduction to the mission including mission plan,scientific objectives,scientific payloads,and its recent development progress.展开更多
Recently some photon models of a Wigner’s friend experiment have led investigators to suggest that objective reality does not exist, and to publish articles with such claims. The public is not equipped to evaluate th...Recently some photon models of a Wigner’s friend experiment have led investigators to suggest that objective reality does not exist, and to publish articles with such claims. The public is not equipped to evaluate the severe limitations of these experiments. The separation of Wigner from the experiment and use of only reversible coherent processes for the friend allow operations that are not possible in ordinary reality according to the latest quantum research. We suggest directly testing the implied claim that objective reality, including incoherent objects with irreversible non-destructive memory, can be held in superposition. We suspect that it will fail, but provide for a graduated approach that may discover something about the conditions for superposition collapse. To this end, we design a thought experiment to model the objective world, investigating under what conditions experimenters in the same world (ensemble member) will be able to record a result and find it does not appear to change. This is not an investigation of hidden variables. To model the objective world, incoherent and irreversible processes must be included. To test for superposition, coherence has to be established. These seem to present a contradiction. The thought experiment suggests new places to look other than size for the origin of objective reality, casts doubt on the Many-Worlds interpretation, and provides a method of testing it.展开更多
With the assumption that the optical variability timescale is dominated by the cooling time of the synchrotron process for BL Lac objects,we estimate time dependent magnetic field strength of the emission region for t...With the assumption that the optical variability timescale is dominated by the cooling time of the synchrotron process for BL Lac objects,we estimate time dependent magnetic field strength of the emission region for two BL Lac objects.The average magnetic field strengths are consistent with those estimated from core shift measurement and spectral energy distribution modelling.Variation of magnetic field strength in the dissipation region is discovered.Variability of flux and magnetic field strength shows no clear correlation,which indicates the variation of magnetic field is not the dominant reason of the variability origin.The evolution of magnetic field strength can provide another approach to constrain the energy dissipation mechanism in jets.展开更多
In this paper, Law of Conservation of Mass （＂The Law＂）, one content standard of junior middle school chemistry, was decomposed based on The Revision of Bloom＇s Taxonomy of Educational Objectives （＂The Revision...In this paper, Law of Conservation of Mass （＂The Law＂）, one content standard of junior middle school chemistry, was decomposed based on The Revision of Bloom＇s Taxonomy of Educational Objectives （＂The Revision＂） and placed in the classification table. In order to understand the teaching objectives more, the relationship between the related activities was studied. Teachers can design the teaching plans based on teaching objective, and determine different evaluations method according to different types of teaching objectives. It will raise students more cognitive activities and promote targeted objectives teaching.展开更多
For a physically possible deformation field of a continuum, the deformation gradient function F can be decomposed into direct sum of a symmetric tensor S and on orthogonal tensor R, which is called S-R decomposition t...For a physically possible deformation field of a continuum, the deformation gradient function F can be decomposed into direct sum of a symmetric tensor S and on orthogonal tensor R, which is called S-R decomposition theorem. In this paper, the S-R decomposition unique existence theorem is proved, by employing matrix and tensor method. Also, a brief proof of its objectivity is given.展开更多
Through the last 17 years of development,China’s light industry has basicallyresolved the short supply of consumergoods,with market demand having been metin quantity,but not in quality.How to adaptto the changes on b...Through the last 17 years of development,China’s light industry has basicallyresolved the short supply of consumergoods,with market demand having been metin quantity,but not in quality.How to adaptto the changes on both the domestic and theinternational markets,speed up structuraladjustment and optimization,promotetechnical progress,develop new products,improve quality,and raise grades andprocessing standards,is the main task for thedevelopment of the light industry in the next15 years.展开更多
基金National Defense Pre-research Fund Project(No.KMGY318002531)。
文摘In order to solve the problem of small objects detection in unmanned aerial vehicle(UAV)aerial images with complex background,a general detection method for multi-scale small objects based on Faster region-based convolutional neural network(Faster R-CNN)is proposed.The bird’s nest on the high-voltage tower is taken as the research object.Firstly,we use the improved convolutional neural network ResNet101 to extract object features,and then use multi-scale sliding windows to obtain the object region proposals on the convolution feature maps with different resolutions.Finally,a deconvolution operation is added to further enhance the selected feature map with higher resolution,and then it taken as a feature mapping layer of the region proposals passing to the object detection sub-network.The detection results of the bird’s nest in UAV aerial images show that the proposed method can precisely detect small objects in aerial images.
基金Supported by the Major Program of the National Science Foundation of China(41590851)the Beijing Municipal Science and Technology Commission(Z181100002918003)。
文摘China’s first Mars exploration mission is scheduled to be launched in 2020.It aims not only to conduct global and comprehensive exploration of Mars by use of an orbiter but also to carry out in situ observation of key sites on Mars with a rover.This mission focuses on the following studies:topography,geomorphology,geological structure,soil characteristics,water-ice distribution,material composition,atmosphere and ionosphere,surface climate,environmental characteristics,Mars internal structure,and Martian magnetic field.It is comprised of an orbiter,a lander,and a rover equipped with 13 scientific payloads.This article will give an introduction to the mission including mission plan,scientific objectives,scientific payloads,and its recent development progress.
文摘Recently some photon models of a Wigner’s friend experiment have led investigators to suggest that objective reality does not exist, and to publish articles with such claims. The public is not equipped to evaluate the severe limitations of these experiments. The separation of Wigner from the experiment and use of only reversible coherent processes for the friend allow operations that are not possible in ordinary reality according to the latest quantum research. We suggest directly testing the implied claim that objective reality, including incoherent objects with irreversible non-destructive memory, can be held in superposition. We suspect that it will fail, but provide for a graduated approach that may discover something about the conditions for superposition collapse. To this end, we design a thought experiment to model the objective world, investigating under what conditions experimenters in the same world (ensemble member) will be able to record a result and find it does not appear to change. This is not an investigation of hidden variables. To model the objective world, incoherent and irreversible processes must be included. To test for superposition, coherence has to be established. These seem to present a contradiction. The thought experiment suggests new places to look other than size for the origin of objective reality, casts doubt on the Many-Worlds interpretation, and provides a method of testing it.
基金supported by the National Natural Science Foundation of China(NSFCGrant Nos.11803081,11947099,U1931203,and 12003014)supported by the CAS Youth Innovation Promotion Association and Basic Research Program of Yunnan Province(202001AW070013)。
文摘With the assumption that the optical variability timescale is dominated by the cooling time of the synchrotron process for BL Lac objects,we estimate time dependent magnetic field strength of the emission region for two BL Lac objects.The average magnetic field strengths are consistent with those estimated from core shift measurement and spectral energy distribution modelling.Variation of magnetic field strength in the dissipation region is discovered.Variability of flux and magnetic field strength shows no clear correlation,which indicates the variation of magnetic field is not the dominant reason of the variability origin.The evolution of magnetic field strength can provide another approach to constrain the energy dissipation mechanism in jets.
文摘In this paper, Law of Conservation of Mass （＂The Law＂）, one content standard of junior middle school chemistry, was decomposed based on The Revision of Bloom＇s Taxonomy of Educational Objectives （＂The Revision＂） and placed in the classification table. In order to understand the teaching objectives more, the relationship between the related activities was studied. Teachers can design the teaching plans based on teaching objective, and determine different evaluations method according to different types of teaching objectives. It will raise students more cognitive activities and promote targeted objectives teaching.
文摘For a physically possible deformation field of a continuum, the deformation gradient function F can be decomposed into direct sum of a symmetric tensor S and on orthogonal tensor R, which is called S-R decomposition theorem. In this paper, the S-R decomposition unique existence theorem is proved, by employing matrix and tensor method. Also, a brief proof of its objectivity is given.
文摘Through the last 17 years of development,China’s light industry has basicallyresolved the short supply of consumergoods,with market demand having been metin quantity,but not in quality.How to adaptto the changes on both the domestic and theinternational markets,speed up structuraladjustment and optimization,promotetechnical progress,develop new products,improve quality,and raise grades andprocessing standards,is the main task for thedevelopment of the light industry in the next15 years.
