Helical polymers have attracted a great deal of attention and been extensively investigated due to their various applications.One of the most importa nt applicati ons of helical polymers is chiral recog nition and res...Helical polymers have attracted a great deal of attention and been extensively investigated due to their various applications.One of the most importa nt applicati ons of helical polymers is chiral recog nition and resolutio n ofe nan tiomersforthe reas on that a pair of e nan tiomers is comm only with differe nt physiological and toxicological behaviors in biological systems.Helical polymers usually prese nt un expected high chiral recogniti on ability to a variety of racemic compo unds.Whatzs more,the chiral recog nition and resolution abilities of the system are depe ndent on the highly ordered helical structures of the helical polymers.This mini review mainly focuses on the recent progress in chiral recognition and resolution based on helical polymers.The synthetic methodology for helical polymers is firstly discussed briefly.Then recent advances of chiral recog nition and resoluti on systems based on helical polymers,especially polyacetylenes and polyisocya nides,are described.We hope this mini review will in spire more in terest in developing helical polymers and en courage further advances in chiral-related disciplines.展开更多
The subtle color distinction is the important function of electronic endoscope imaging diagnosis.However,after image acquisition,transmission and display,color distortions of intracorporeal organs or tissues occur ine...The subtle color distinction is the important function of electronic endoscope imaging diagnosis.However,after image acquisition,transmission and display,color distortions of intracorporeal organs or tissues occur inevitably,which are adverse to analyze image features accurately or to diagnose early pathological changes.A real-time color correction algorithm based on fourneighborhood and polynomial regression in YUV color space is proposed.Based on polynomial regression the color correction matrix is calculated in YUV color space according to the dierences between standard values of color checker and measured values of that imaged by the endoscope.As the correction is only executed on U and V components in YUV color space,the defect that the color of corrected images in RGB color space will change along with luminance can be avoided,and then the stability of image color is improved.Owing to four-neighborhood processing,the signal-to-noise ratio of corrected images is enhanced and the processing speed of correction algorithm is accelerated.The average color dierence is reduced from 0.3944 to 0.2850 by application of the proposed algorithm in high-denition electronic endoscope.A total of 17 frames per second can be achieved at the resolution of 1280800,and the color characteristics of the image after processing match that of human visual system.展开更多
For socialized animals,such as prinlates,emotions arc the expression of internal states,which may be recognized by others to adjust an in dividual's potential actions(Girard and Bellone 2020).Facial expressions ar...For socialized animals,such as prinlates,emotions arc the expression of internal states,which may be recognized by others to adjust an in dividual's potential actions(Girard and Bellone 2020).Facial expressions are therefore important signals in communication(e.g.,happy or in pain)and can help individuals understand potential meanings between each other(Dolensek et al.2020).Facial expressions can be expressed and processed freely and are useful in social interactions and bonding(Waller et al.2016).展开更多
A mathematical model of the bellows dispersion system is developed by combining the interior ballistic theory with structural dynamics theory to describe the deformation course of bellows. By analyzing the physical mo...A mathematical model of the bellows dispersion system is developed by combining the interior ballistic theory with structural dynamics theory to describe the deformation course of bellows. By analyzing the physical model of the bellows dispersion system, the dispersion course is divided into three stages. For each stage, mathematical model is built and its terminal conditions are given. The numerical simulation is based on the Runge-Kutta method and differential quadrature method. Simulation results of the model agree with those of the model built by only interior ballistics theory. However, this model is congruous with the actual dispersion course and can more easily determine the dispersion time and submunition displacement.展开更多
钛合金由于导热率低,在磨削过程中工件表面容易产生烧伤或裂纹。采用图像法进行在线表面烧伤识别时,受到磨削液等现场因素的影响,采集的工件图像存在运动模糊或者目标区域被遮挡等现象,影响深度学习模型的识别效果。针对现场图像受损的...钛合金由于导热率低,在磨削过程中工件表面容易产生烧伤或裂纹。采用图像法进行在线表面烧伤识别时,受到磨削液等现场因素的影响,采集的工件图像存在运动模糊或者目标区域被遮挡等现象,影响深度学习模型的识别效果。针对现场图像受损的问题,采用对偶学习和跳跃连接的方法,设计生成对抗网络的生成器、判别器和损失函数,对细节信息进行修复,重建退化图像。试验结果表明,经过重建的钛合金磨削现场图像的峰值信噪比(peak signal to noise ratio,简称PSNR)平均值达到25以上,结构相似度(structural similarity,简称SSIM)平均值达到0.77以上。采用基于模型微调的方法对重建后图像进行烧伤识别,准确率达到90%以上。展开更多
针对现有水果识别方法需大量水果样本学习或仅对单一特征进行识别而导致的识别率较低的问题,提出一种基于水果图像处理的水果颜色和形状特征参数的提取方法、基于灰色关联分析和模糊隶属度匹配的球形水果自动识别方法。该方法通过提取...针对现有水果识别方法需大量水果样本学习或仅对单一特征进行识别而导致的识别率较低的问题,提出一种基于水果图像处理的水果颜色和形状特征参数的提取方法、基于灰色关联分析和模糊隶属度匹配的球形水果自动识别方法。该方法通过提取水果图像关注区域(region of interest,ROI)的颜色和形状特征,建立参比水果的颜色特征参比数据库和形状特征隶属度函数,计算待识别水果与参比水果颜色特征的灰色加权关联度,求取待识别水果对于参比水果形状特征参数的模糊隶属度,按各特征量等权的原则合成待识别水果对参比水果的总匹配度,并根据总匹配度的大小实现待识别水果种类的判别。大量实验结果表明:该方法简单、有效,不需要大样本量水果的学习和训练,平均识别正确率达到99%以上。展开更多
基金by the National Natural Science Foundation of China(Nos.51803045,21971052,22071041 and 51673057)the Fundamental Research Funds for the Central Universities(No.JZ2021HGTB0084,PA2020GDSK0069 and PA2020GDSK0070).
文摘Helical polymers have attracted a great deal of attention and been extensively investigated due to their various applications.One of the most importa nt applicati ons of helical polymers is chiral recog nition and resolutio n ofe nan tiomersforthe reas on that a pair of e nan tiomers is comm only with differe nt physiological and toxicological behaviors in biological systems.Helical polymers usually prese nt un expected high chiral recogniti on ability to a variety of racemic compo unds.Whatzs more,the chiral recog nition and resolution abilities of the system are depe ndent on the highly ordered helical structures of the helical polymers.This mini review mainly focuses on the recent progress in chiral recognition and resolution based on helical polymers.The synthetic methodology for helical polymers is firstly discussed briefly.Then recent advances of chiral recog nition and resoluti on systems based on helical polymers,especially polyacetylenes and polyisocya nides,are described.We hope this mini review will in spire more in terest in developing helical polymers and en courage further advances in chiral-related disciplines.
基金supported by grants from National Key Technology R&D Program(Grant No.:2011BAI12B06)the Fundamental Research Funds for the Central Universities(Grant No.:2012FZA5023).
文摘The subtle color distinction is the important function of electronic endoscope imaging diagnosis.However,after image acquisition,transmission and display,color distortions of intracorporeal organs or tissues occur inevitably,which are adverse to analyze image features accurately or to diagnose early pathological changes.A real-time color correction algorithm based on fourneighborhood and polynomial regression in YUV color space is proposed.Based on polynomial regression the color correction matrix is calculated in YUV color space according to the dierences between standard values of color checker and measured values of that imaged by the endoscope.As the correction is only executed on U and V components in YUV color space,the defect that the color of corrected images in RGB color space will change along with luminance can be avoided,and then the stability of image color is improved.Owing to four-neighborhood processing,the signal-to-noise ratio of corrected images is enhanced and the processing speed of correction algorithm is accelerated.The average color dierence is reduced from 0.3944 to 0.2850 by application of the proposed algorithm in high-denition electronic endoscope.A total of 17 frames per second can be achieved at the resolution of 1280800,and the color characteristics of the image after processing match that of human visual system.
基金This study was supported by the Key Program of the National Natural Science Fund(31730104)National Natural Science Foundation of China(31801981)+5 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31020302)National Key Program of Research and Development,Ministry of Science and Technology(2016YFC0503200)Innovation Capability Support Program of Shaanxi(2020KJXX-008)Foundation of Shaanxi Academy of Sciences of China(2016K-20,2018K-16-04,2019ZY-JCTJ-06)Key Research and Development Program of Shaanxi Province of China(2018PT-04)One Institute One Brand Foundation of Shaanxi Academy of Sciences(2020k-01).
文摘For socialized animals,such as prinlates,emotions arc the expression of internal states,which may be recognized by others to adjust an in dividual's potential actions(Girard and Bellone 2020).Facial expressions are therefore important signals in communication(e.g.,happy or in pain)and can help individuals understand potential meanings between each other(Dolensek et al.2020).Facial expressions can be expressed and processed freely and are useful in social interactions and bonding(Waller et al.2016).
文摘A mathematical model of the bellows dispersion system is developed by combining the interior ballistic theory with structural dynamics theory to describe the deformation course of bellows. By analyzing the physical model of the bellows dispersion system, the dispersion course is divided into three stages. For each stage, mathematical model is built and its terminal conditions are given. The numerical simulation is based on the Runge-Kutta method and differential quadrature method. Simulation results of the model agree with those of the model built by only interior ballistics theory. However, this model is congruous with the actual dispersion course and can more easily determine the dispersion time and submunition displacement.
文摘钛合金由于导热率低,在磨削过程中工件表面容易产生烧伤或裂纹。采用图像法进行在线表面烧伤识别时,受到磨削液等现场因素的影响,采集的工件图像存在运动模糊或者目标区域被遮挡等现象,影响深度学习模型的识别效果。针对现场图像受损的问题,采用对偶学习和跳跃连接的方法,设计生成对抗网络的生成器、判别器和损失函数,对细节信息进行修复,重建退化图像。试验结果表明,经过重建的钛合金磨削现场图像的峰值信噪比(peak signal to noise ratio,简称PSNR)平均值达到25以上,结构相似度(structural similarity,简称SSIM)平均值达到0.77以上。采用基于模型微调的方法对重建后图像进行烧伤识别,准确率达到90%以上。
文摘针对现有水果识别方法需大量水果样本学习或仅对单一特征进行识别而导致的识别率较低的问题,提出一种基于水果图像处理的水果颜色和形状特征参数的提取方法、基于灰色关联分析和模糊隶属度匹配的球形水果自动识别方法。该方法通过提取水果图像关注区域(region of interest,ROI)的颜色和形状特征,建立参比水果的颜色特征参比数据库和形状特征隶属度函数,计算待识别水果与参比水果颜色特征的灰色加权关联度,求取待识别水果对于参比水果形状特征参数的模糊隶属度,按各特征量等权的原则合成待识别水果对参比水果的总匹配度,并根据总匹配度的大小实现待识别水果种类的判别。大量实验结果表明:该方法简单、有效,不需要大样本量水果的学习和训练,平均识别正确率达到99%以上。
