Dielectric elastomer actuators (DEAs) artificial muscle is a typical interdisciplinary research category, which has developed by leaps and bounds in the past 20 years, showing great application prospects in various fi...Dielectric elastomer actuators (DEAs) artificial muscle is a typical interdisciplinary research category, which has developed by leaps and bounds in the past 20 years, showing great application prospects in various fields. Upon external electrical stimulation, dielectric elastomers (DEs) display large deformation, high energy density and fast response, affording a promising material candidate for soft robotics. Herein, the working mechanisms, commonly used materials as well as the concepts for improving the performance of DEA materials are introduced. Various DEA driven soft robots, including soft grippers, bioinspired artificial arms, crawling/walking/underwater/flying/jumping soft robots and tunable lenses, are then described in detail. Finally, the main challenges of DEA driven soft robots are summarized, and some perspectives for promoting the practical application of DEAs are also proposed.展开更多
Elastic or plastic bendable organic crystals have attracted increasing attention in the field of crystal engineering.For the application of flexible materials,the applicable temperature range can not be ignored.Howeve...Elastic or plastic bendable organic crystals have attracted increasing attention in the field of crystal engineering.For the application of flexible materials,the applicable temperature range can not be ignored.However,studies on the flexible organic crystals reported so far have not involved the effect of temperature on the mechanical properties of these materials.Here,organic crystals of 9,10-bis(phenylethynyl)anthracene with phase-dependent mechanical properties over wide temperature ranges are reported.展开更多
Digital image forgery (DIF) is a prevalent issue in the modern age, where malicious actors manipulate images for various purposes, including deception and misinformation. Detecting such forgeries is a critical task fo...Digital image forgery (DIF) is a prevalent issue in the modern age, where malicious actors manipulate images for various purposes, including deception and misinformation. Detecting such forgeries is a critical task for maintaining the integrity of digital content. This thesis explores the use of Modified Error Level Analysis (ELA) in combination with a Convolutional Neural Network (CNN), as well as, Feedforward Neural Network (FNN) model to detect digital image forgeries. Additionally, incorporation of Explainable Artificial Intelligence (XAI) to this research provided insights into the process of decision-making by the models. The study trains and tests the models on the CASIA2 dataset, emphasizing both authentic and forged images. The CNN model is trained and evaluated, and Explainable AI (SHapley Additive exPlanation— SHAP) is incorporated to explain the model’s predictions. Similarly, the FNN model is trained and evaluated, and XAI (SHAP) is incorporated to explain the model’s predictions. The results obtained from the analysis reveals that the proposed approach using CNN model is most effective in detecting image forgeries and provides valuable explanations for decision interpretability.展开更多
物质平衡是冰川与气候相互作用的关键桥梁,对气候变化非常敏感。基于青冰滩72号冰川2008-2014年冰面花杆和雪坑的观测资料,结合Landsat系列卫星影像,利用零平衡线法对青冰滩72号冰川的物质平衡进行计算和分析。结果表明:青冰滩72号冰川2...物质平衡是冰川与气候相互作用的关键桥梁,对气候变化非常敏感。基于青冰滩72号冰川2008-2014年冰面花杆和雪坑的观测资料,结合Landsat系列卫星影像,利用零平衡线法对青冰滩72号冰川的物质平衡进行计算和分析。结果表明:青冰滩72号冰川2008-2014年平均物质平衡梯度为(0.86±0.19)m w. e.?(100m)-1;平衡线高度在(4 109±23)^(4 317±92)m a. s. l.之间变化,平均为(4 167.5±33.2)m a. s. l。同时,青冰滩72号冰川年净物质平衡介于-1.23m w. e.^+0.31m w. e.,年平均为-0.38m w. e.,累积物质平衡为-2.27m w. e.。此外,与位于天山地区图尤克苏冰川、乌鲁木齐河源1号冰川平衡线高度和累积物质平衡的比较发现,青冰滩72号冰川平衡线高度和物质平衡的变化与图尤克苏冰川相似,而与乌鲁木齐河源1号冰川的差异相对较大。展开更多
基金support from the National Natural Science Foundation of China(Grant No.51525301)the Talent Cultivation of State Key Laboratory of Organic-Inorganic Composites(No.OIC-D2021002).
文摘Dielectric elastomer actuators (DEAs) artificial muscle is a typical interdisciplinary research category, which has developed by leaps and bounds in the past 20 years, showing great application prospects in various fields. Upon external electrical stimulation, dielectric elastomers (DEs) display large deformation, high energy density and fast response, affording a promising material candidate for soft robotics. Herein, the working mechanisms, commonly used materials as well as the concepts for improving the performance of DEA materials are introduced. Various DEA driven soft robots, including soft grippers, bioinspired artificial arms, crawling/walking/underwater/flying/jumping soft robots and tunable lenses, are then described in detail. Finally, the main challenges of DEA driven soft robots are summarized, and some perspectives for promoting the practical application of DEAs are also proposed.
基金supported by the National Natural Science Foundation of China(no.51773077).
文摘Elastic or plastic bendable organic crystals have attracted increasing attention in the field of crystal engineering.For the application of flexible materials,the applicable temperature range can not be ignored.However,studies on the flexible organic crystals reported so far have not involved the effect of temperature on the mechanical properties of these materials.Here,organic crystals of 9,10-bis(phenylethynyl)anthracene with phase-dependent mechanical properties over wide temperature ranges are reported.
文摘Digital image forgery (DIF) is a prevalent issue in the modern age, where malicious actors manipulate images for various purposes, including deception and misinformation. Detecting such forgeries is a critical task for maintaining the integrity of digital content. This thesis explores the use of Modified Error Level Analysis (ELA) in combination with a Convolutional Neural Network (CNN), as well as, Feedforward Neural Network (FNN) model to detect digital image forgeries. Additionally, incorporation of Explainable Artificial Intelligence (XAI) to this research provided insights into the process of decision-making by the models. The study trains and tests the models on the CASIA2 dataset, emphasizing both authentic and forged images. The CNN model is trained and evaluated, and Explainable AI (SHapley Additive exPlanation— SHAP) is incorporated to explain the model’s predictions. Similarly, the FNN model is trained and evaluated, and XAI (SHAP) is incorporated to explain the model’s predictions. The results obtained from the analysis reveals that the proposed approach using CNN model is most effective in detecting image forgeries and provides valuable explanations for decision interpretability.
文摘物质平衡是冰川与气候相互作用的关键桥梁,对气候变化非常敏感。基于青冰滩72号冰川2008-2014年冰面花杆和雪坑的观测资料,结合Landsat系列卫星影像,利用零平衡线法对青冰滩72号冰川的物质平衡进行计算和分析。结果表明:青冰滩72号冰川2008-2014年平均物质平衡梯度为(0.86±0.19)m w. e.?(100m)-1;平衡线高度在(4 109±23)^(4 317±92)m a. s. l.之间变化,平均为(4 167.5±33.2)m a. s. l。同时,青冰滩72号冰川年净物质平衡介于-1.23m w. e.^+0.31m w. e.,年平均为-0.38m w. e.,累积物质平衡为-2.27m w. e.。此外,与位于天山地区图尤克苏冰川、乌鲁木齐河源1号冰川平衡线高度和累积物质平衡的比较发现,青冰滩72号冰川平衡线高度和物质平衡的变化与图尤克苏冰川相似,而与乌鲁木齐河源1号冰川的差异相对较大。
