Unmanned surface vehicle(USV)is currently a hot research topic in maritime communication network(MCN),where denoising and semantic segmentation of maritime images taken by USV have been rarely studied.The former has r...Unmanned surface vehicle(USV)is currently a hot research topic in maritime communication network(MCN),where denoising and semantic segmentation of maritime images taken by USV have been rarely studied.The former has recently researched on autoencoder model used for image denoising,but the existed models are too complicated to be suitable for real-time detection of USV.In this paper,we proposed a lightweight autoencoder combined with inception module for maritime image denoising in different noisy environments and explore the effect of different inception modules on the denoising performance.Furthermore,we completed the semantic segmentation task for maritime images taken by USV utilizing the pretrained U-Net model with tuning,and compared them with original U-Net model based on different backbone.Subsequently,we compared the semantic segmentation of noised and denoised maritime images respectively to explore the effect of image noise on semantic segmentation performance.Case studies are provided to prove the feasibility of our proposed denoising and segmentation method.Finally,a simple integrated communication system combining image denoising and segmentation for USV is shown.展开更多
Cold molecules have great scientific significance in high-resolution spectroscopy, precision measurement of physical constants, cold collision, and cold chemistry. Supersonic expansion is a conventional and versatile ...Cold molecules have great scientific significance in high-resolution spectroscopy, precision measurement of physical constants, cold collision, and cold chemistry. Supersonic expansion is a conventional and versatile method to produce cold molecules with high kinetic energies. We theoretically show here that fast-moving molecules from supersonic expansion can be effectively decelerated to any desired velocity with a rotating laser beam. The orbiting focus spot of the red-detuned laser serves as a two-dimensional potential well for the molecules. We analyze the dynamics of the molecules inside the decelerating potential well and investigate the dependence of their phase acceptance by the potential well on the tilting angle of the laser beam. ND_3 molecules are used in the test of the scheme and their trajectories under the impact of the decelerating potential well are numerically simulated using the Monte Carlo method. For instance, with a laser beam of20 k W in power focused into a pot of 40 μm in waist radius, ND3 molecules of 250 m/s can be brought to a standstill by the decelerating potential well within a time interval of about 0.73 ms. The total angle covered by the rotating laser beam is about 5.24？with the distance travelled by the potential well being about 9.13 cm. In fact, the molecules can be decelerated to any desired velocity depending on the parameters adopted. This scheme is simple in structure and easy to be realized in experiment. In addition, it is applicable to decelerating both molecules and atoms.展开更多
The plants of the genus Schisandra of the Schisandraceae family include the genus Schisandra and the genus Kadsura.In recent years,many kinds of triterpenoids have been isolated from the plants of genus Schisandra.Tri...The plants of the genus Schisandra of the Schisandraceae family include the genus Schisandra and the genus Kadsura.In recent years,many kinds of triterpenoids have been isolated from the plants of genus Schisandra.Triterpenoids have attracted the attention of phytochemists and pharmacologists because they have novel skeletons and good anti-HIV,immunosuppressive and anti-tumor activities.This study provides an overview of the triterpenoids from the genus Schisandra and their biological activities.展开更多
The plants of the genus Schisandra belong to the Schisandraceae family.As one of the main active components of genus Schisandra,lignans have rich biological activities,including anti-inflammatory,anti-tumor,anti-HIV a...The plants of the genus Schisandra belong to the Schisandraceae family.As one of the main active components of genus Schisandra,lignans have rich biological activities,including anti-inflammatory,anti-tumor,anti-HIV and PAF antagonism.This article summarizes and classifies the types and activities of lignans isolated from the genus Schisandra in the past ten years.展开更多
基金Natural Science Foundation of Fujian Province(No.2019J05026)in part by the Education Scientific Research Project for Young Teachers of Fujian Province(No.JT180053).
文摘Unmanned surface vehicle(USV)is currently a hot research topic in maritime communication network(MCN),where denoising and semantic segmentation of maritime images taken by USV have been rarely studied.The former has recently researched on autoencoder model used for image denoising,but the existed models are too complicated to be suitable for real-time detection of USV.In this paper,we proposed a lightweight autoencoder combined with inception module for maritime image denoising in different noisy environments and explore the effect of different inception modules on the denoising performance.Furthermore,we completed the semantic segmentation task for maritime images taken by USV utilizing the pretrained U-Net model with tuning,and compared them with original U-Net model based on different backbone.Subsequently,we compared the semantic segmentation of noised and denoised maritime images respectively to explore the effect of image noise on semantic segmentation performance.Case studies are provided to prove the feasibility of our proposed denoising and segmentation method.Finally,a simple integrated communication system combining image denoising and segmentation for USV is shown.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504112,91536218,and 11604100)
文摘Cold molecules have great scientific significance in high-resolution spectroscopy, precision measurement of physical constants, cold collision, and cold chemistry. Supersonic expansion is a conventional and versatile method to produce cold molecules with high kinetic energies. We theoretically show here that fast-moving molecules from supersonic expansion can be effectively decelerated to any desired velocity with a rotating laser beam. The orbiting focus spot of the red-detuned laser serves as a two-dimensional potential well for the molecules. We analyze the dynamics of the molecules inside the decelerating potential well and investigate the dependence of their phase acceptance by the potential well on the tilting angle of the laser beam. ND_3 molecules are used in the test of the scheme and their trajectories under the impact of the decelerating potential well are numerically simulated using the Monte Carlo method. For instance, with a laser beam of20 k W in power focused into a pot of 40 μm in waist radius, ND3 molecules of 250 m/s can be brought to a standstill by the decelerating potential well within a time interval of about 0.73 ms. The total angle covered by the rotating laser beam is about 5.24？with the distance travelled by the potential well being about 9.13 cm. In fact, the molecules can be decelerated to any desired velocity depending on the parameters adopted. This scheme is simple in structure and easy to be realized in experiment. In addition, it is applicable to decelerating both molecules and atoms.
基金This work was supported by the National Key Research and Development Program of China(2017YFC1701200)Leading Talents of Science and Technology Innovation in Liaoning Province(XLYC1902101)Liaoning Provincial Doctoral Research Start-up Fund(2019-BS-224).
文摘The plants of the genus Schisandra of the Schisandraceae family include the genus Schisandra and the genus Kadsura.In recent years,many kinds of triterpenoids have been isolated from the plants of genus Schisandra.Triterpenoids have attracted the attention of phytochemists and pharmacologists because they have novel skeletons and good anti-HIV,immunosuppressive and anti-tumor activities.This study provides an overview of the triterpenoids from the genus Schisandra and their biological activities.
基金supported by the National Key Research and Development Program of China(2017YFC1701200),Leading Talents of Science and Technology Innovation in Liaoning Province(XLYC1902101).
文摘The plants of the genus Schisandra belong to the Schisandraceae family.As one of the main active components of genus Schisandra,lignans have rich biological activities,including anti-inflammatory,anti-tumor,anti-HIV and PAF antagonism.This article summarizes and classifies the types and activities of lignans isolated from the genus Schisandra in the past ten years.
