Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics, Recent advancements in materials science, mechanics, and stretchable electronics have led ...Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics, Recent advancements in materials science, mechanics, and stretchable electronics have led to successful development of bioinspired cameras that resemble the structures and functions of biological light-sensing organs. In this review, we discuss some recent progresses in mechanics of bioinspired imaging systems, including tunable hemispherical eyeball camera and artificial compound eye camera. The mechanics models and results reviewed in this article can provide efficient tools for design and optimization of such systems, as well as other related optoelectronic systems that combine rigid elements with soft substrates.展开更多
This paper describes the deep rockburst simulation system to reproduce the granite instantaneous rockburst process.Based on the PIV(Particle Image Velocimetry)technique,quantitative analysis of a rockburst,the images ...This paper describes the deep rockburst simulation system to reproduce the granite instantaneous rockburst process.Based on the PIV(Particle Image Velocimetry)technique,quantitative analysis of a rockburst,the images of tracer particle,displacement and strain fields can be obtained,and the debris trajectory described.According to the observation of on-site tests,the dynamic rockburst is actually a gas–solid high speed flow process,which is caused by the interaction of rock fragments and surrounding air.With the help of analysis on high speed video and PIV images,the granite rockburst failure process is composed of six stages of platey fragment spalling and debris ejection.Meanwhile,the elastic energy for these six stages has been calculated to study the energy variation.The results indicate that the rockburst process can be summarized as:an initiating stage,intensive developing stage and gradual decay stage.This research will be helpful for our further understanding of the rockburst mechanism.展开更多
Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for non-invasive and direct assessment of the viscoelastic properties of materials.Recent advances of background-free confocal Br...Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for non-invasive and direct assessment of the viscoelastic properties of materials.Recent advances of background-free confocal Brillouin spectrometer allows investigators to acquire the Brillouin spectra for turbid samples as well as transparent ones.However,due to strong signal loss induced by the imperfect optical setup,the Brillouin photons are usually immersed in background noise.In this report,we proposed and experimentally demonstrated multiple approaches to enhance the signal collction eficiency.A signal enhancement by>4 times can be observed,enabling ob-servation of ultra-weak signals.展开更多
Recently,infrared polarization imaging technology has become a research hotspot due to its ability to better resolve the physicochemical properties of objects and significantly enhance the target characteristics.Howev...Recently,infrared polarization imaging technology has become a research hotspot due to its ability to better resolve the physicochemical properties of objects and significantly enhance the target characteristics.However,the traditional infrared polarization imaging is limited to similar imaging mechanism restrictions,and it is difficult to acquire the polarization information of a wide-area posture in real time.Therefore,we report a combination of hardware and software for super-wide-field-of-view long-wave infrared gaze polarization imaging technology.Utilizing the non-similar imaging theory and adopting the inter-lens coupling holographic linegrid infrared polarization device scheme,we designed the infrared gazing polarized lens with a field-of-view of over 160°.Based on the fusion of infrared intensity images and infrared polarization images,a multi-strategy detail feature extraction and fusion network is constructed.Super-wide-field-of-view(150°×120°),large face array(1040×830),detail-rich infrared fusion images are acquired during the test.We have accomplished the tasks of vehicle target detection and infrared camouflage target recognition efficiently using the fusion images,and verified the superiority of recognizing far-field targets.Our implementation should enable and empower applications in machine vision,intelligent driving,and target detection under complex environments.展开更多
The electronic structure and some one-electron properties of binary intermetallic compounds Fe3Al (the F1∶Al4 model cluster) and FeAl (the Fe7Al8 and Fe4Al4 model clusters) are investigated by the SCF-Xα-SW method. ...The electronic structure and some one-electron properties of binary intermetallic compounds Fe3Al (the F1∶Al4 model cluster) and FeAl (the Fe7Al8 and Fe4Al4 model clusters) are investigated by the SCF-Xα-SW method. The results show that the binding tendency between an Fe atom and the Fe3Al cluster is a little weaker than that between an Al atom and the Fe3Al cluster, which is in contrast to the case in FeAl. And charge is transferred from Al atoms to Fe atoms in both systems. Thus it is concluded that Al atoms contribute to the FIM image of Fe3Al whatever the imaging mechanism, selective evaporation or selective ionization is, which is in good agreement with our FIM experimental results. For FeAl, no definite experimental evidence regarding FIM imaging atom species is available so far. But our calculated result that Al atoms will be evaporated preferentially leads to the prediction that Fe atoms will be imaged in FIM micrographs.展开更多
The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the exist...The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the existing deep learning-based methods for this task are mainly based on image classification, which fails to provide the location information of diseased silkworms. To this end, this study proposed an object detection-based method for identifying and locating healthy and diseased silkworms. Images of mixed healthy and diseased silkworms were collected using a mobile phone, and the category and location of each silkworm were labeled using LabelImg as a labeling tool to construct an image dataset for object detection. Based on the one-step detection model YOLOv5s, the ConvNeXt-Attention-YOLOv5 (CA-YOLOv5) model was designed in which the large kernel with depth-wise separable convolution (7×7 dw-conv) of ConvNeXt was adopted to expand receptive fields and the channel attention mechanism ECANet was added to enhance the capability of feature extraction. Experiments showed that the mean average precision (mAP) values of CA-YOLOv5 for healthy and diseased silkworms reached 96.46%, which is 1.35% better than that achieved via YOLOv5s. At the same time, the overall performance of CA-YOLOv5 was significantly better than state-of-the-art one-step models, such as Single Shot MultiBox Detector (SSD), CenterNet, and EfficientDet, and even improved YOLOv5 using image attention mechanism and a lightweight backbone, like SENet-YOLOv5 and MobileNet-YOLOv5. The results of this study can provide an important basis for the accurate positioning of diseased silkworms in precision disease control technology and equipment development.展开更多
基金support from ACS Petroleum Research Fund(Grant No.53780-DNI7)NSF(Grant No.CMMI-1405355)
文摘Imaging systems in nature have attracted a lot of research interest due to their superior optical and imaging characteristics, Recent advancements in materials science, mechanics, and stretchable electronics have led to successful development of bioinspired cameras that resemble the structures and functions of biological light-sensing organs. In this review, we discuss some recent progresses in mechanics of bioinspired imaging systems, including tunable hemispherical eyeball camera and artificial compound eye camera. The mechanics models and results reviewed in this article can provide efficient tools for design and optimization of such systems, as well as other related optoelectronic systems that combine rigid elements with soft substrates.
基金supported by the National Natural Science Foundation of China (No.41172270)National Basic Research Program (No.2011CB201201)
文摘This paper describes the deep rockburst simulation system to reproduce the granite instantaneous rockburst process.Based on the PIV(Particle Image Velocimetry)technique,quantitative analysis of a rockburst,the images of tracer particle,displacement and strain fields can be obtained,and the debris trajectory described.According to the observation of on-site tests,the dynamic rockburst is actually a gas–solid high speed flow process,which is caused by the interaction of rock fragments and surrounding air.With the help of analysis on high speed video and PIV images,the granite rockburst failure process is composed of six stages of platey fragment spalling and debris ejection.Meanwhile,the elastic energy for these six stages has been calculated to study the energy variation.The results indicate that the rockburst process can be summarized as:an initiating stage,intensive developing stage and gradual decay stage.This research will be helpful for our further understanding of the rockburst mechanism.
基金supported by the start-up funds available through Texas A&M Universitysupport of the NIH (Grant#R21EB011703) and the NSF (ECCS Grant#10665620,DBI Grant#10665621 and CBET Grant#10665623).
文摘Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows for non-invasive and direct assessment of the viscoelastic properties of materials.Recent advances of background-free confocal Brillouin spectrometer allows investigators to acquire the Brillouin spectra for turbid samples as well as transparent ones.However,due to strong signal loss induced by the imperfect optical setup,the Brillouin photons are usually immersed in background noise.In this report,we proposed and experimentally demonstrated multiple approaches to enhance the signal collction eficiency.A signal enhancement by>4 times can be observed,enabling ob-servation of ultra-weak signals.
基金National Natural Science Foundation of China(62171467)Natural Science Foundation of Hebei Province(F2021506004)。
文摘Recently,infrared polarization imaging technology has become a research hotspot due to its ability to better resolve the physicochemical properties of objects and significantly enhance the target characteristics.However,the traditional infrared polarization imaging is limited to similar imaging mechanism restrictions,and it is difficult to acquire the polarization information of a wide-area posture in real time.Therefore,we report a combination of hardware and software for super-wide-field-of-view long-wave infrared gaze polarization imaging technology.Utilizing the non-similar imaging theory and adopting the inter-lens coupling holographic linegrid infrared polarization device scheme,we designed the infrared gazing polarized lens with a field-of-view of over 160°.Based on the fusion of infrared intensity images and infrared polarization images,a multi-strategy detail feature extraction and fusion network is constructed.Super-wide-field-of-view(150°×120°),large face array(1040×830),detail-rich infrared fusion images are acquired during the test.We have accomplished the tasks of vehicle target detection and infrared camouflage target recognition efficiently using the fusion images,and verified the superiority of recognizing far-field targets.Our implementation should enable and empower applications in machine vision,intelligent driving,and target detection under complex environments.
基金Project supported by the National Natu ral Science Foundation of Chm(Grant No.59771018).
文摘The electronic structure and some one-electron properties of binary intermetallic compounds Fe3Al (the F1∶Al4 model cluster) and FeAl (the Fe7Al8 and Fe4Al4 model clusters) are investigated by the SCF-Xα-SW method. The results show that the binding tendency between an Fe atom and the Fe3Al cluster is a little weaker than that between an Al atom and the Fe3Al cluster, which is in contrast to the case in FeAl. And charge is transferred from Al atoms to Fe atoms in both systems. Thus it is concluded that Al atoms contribute to the FIM image of Fe3Al whatever the imaging mechanism, selective evaporation or selective ionization is, which is in good agreement with our FIM experimental results. For FeAl, no definite experimental evidence regarding FIM imaging atom species is available so far. But our calculated result that Al atoms will be evaporated preferentially leads to the prediction that Fe atoms will be imaged in FIM micrographs.
基金support provided by the Sichuan Science and Technology Program,China (Grant No.2023NSFSC0498)the National Modern Agricultural Industrial Technology System Special Project,China (Grant No.CARS-18).
文摘The accurate identification and localization of diseased silkworms is an important task in the research of disease precision control technology and equipment development in the sericulture industry. However, the existing deep learning-based methods for this task are mainly based on image classification, which fails to provide the location information of diseased silkworms. To this end, this study proposed an object detection-based method for identifying and locating healthy and diseased silkworms. Images of mixed healthy and diseased silkworms were collected using a mobile phone, and the category and location of each silkworm were labeled using LabelImg as a labeling tool to construct an image dataset for object detection. Based on the one-step detection model YOLOv5s, the ConvNeXt-Attention-YOLOv5 (CA-YOLOv5) model was designed in which the large kernel with depth-wise separable convolution (7×7 dw-conv) of ConvNeXt was adopted to expand receptive fields and the channel attention mechanism ECANet was added to enhance the capability of feature extraction. Experiments showed that the mean average precision (mAP) values of CA-YOLOv5 for healthy and diseased silkworms reached 96.46%, which is 1.35% better than that achieved via YOLOv5s. At the same time, the overall performance of CA-YOLOv5 was significantly better than state-of-the-art one-step models, such as Single Shot MultiBox Detector (SSD), CenterNet, and EfficientDet, and even improved YOLOv5 using image attention mechanism and a lightweight backbone, like SENet-YOLOv5 and MobileNet-YOLOv5. The results of this study can provide an important basis for the accurate positioning of diseased silkworms in precision disease control technology and equipment development.
