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Observations of the solar corona during the total solar eclipse on 21 August 2017
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作者 Hui Tian ZhongQuan Qu +15 位作者 YaJie Chen LinHua Deng ZhengHua Huang Hao Li Yue Zhong Yu Liang JingWen Zhang YiGong Zhang BaoLi Lun XiangMing Cheng XiaoLi Yan ZhiKe Xue YuXin Xin zhiming song YingJie Zhu Tanmoy Samanta 《Earth and Planetary Physics》 2017年第1期68-71,共4页
The Sun’s tenuous outer atmosphere,the corona,emits only about one-millionth as much light as the solar surface.In ancient times the corona was observed by human beings only during total solar eclipses,when the stron... The Sun’s tenuous outer atmosphere,the corona,emits only about one-millionth as much light as the solar surface.In ancient times the corona was observed by human beings only during total solar eclipses,when the strong emission of visible light from the photosphere was completely blocked by the Moon.In 1931, 展开更多
关键词 solar corona solar eclipse solar magnetic fields coronal heating
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A Multi-strategy Improved Snake Optimizer Assisted with Population Crowding Analysis for Engineering Design Problems
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作者 Lei Peng Zhuoming Yuan +4 位作者 Guangming Dai Maocai Wang Jian Li zhiming song Xiaoyu Chen 《Journal of Bionic Engineering》 SCIE EI CSCD 2024年第3期1567-1591,共25页
Snake Optimizer(SO)is a novel Meta-heuristic Algorithm(MA)inspired by the mating behaviour of snakes,which has achieved success in global numerical optimization problems and practical engineering applications.However,... Snake Optimizer(SO)is a novel Meta-heuristic Algorithm(MA)inspired by the mating behaviour of snakes,which has achieved success in global numerical optimization problems and practical engineering applications.However,it also has certain drawbacks for the exploration stage and the egg hatch process,resulting in slow convergence speed and inferior solution quality.To address the above issues,a novel multi-strategy improved SO(MISO)with the assistance of population crowding analysis is proposed in this article.In the algorithm,a novel multi-strategy operator is designed for the exploration stage,which not only focuses on using the information of better performing individuals to improve the quality of solution,but also focuses on maintaining population diversity.To boost the efficiency of the egg hatch process,the multi-strategy egg hatch process is proposed to regenerate individuals according to the results of the population crowding analysis.In addition,a local search method is employed to further enhance the convergence speed and the local search capability.MISO is first compared with three sets of algorithms in the CEC2020 benchmark functions,including SO with its two recently discussed variants,ten advanced MAs,and six powerful CEC competition algorithms.The performance of MISO is then verified on five practical engineering design problems.The experimental results show that MISO provides a promising performance for the above optimization cases in terms of convergence speed and solution quality. 展开更多
关键词 Snake optimizer Multi-strategy Population crowding analysis Engineering design problem
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Boosting electrocatalytic water splitting via metal-metalloid combined modulation in quaternary Ni-Fe-P-B amorphous compound 被引量:10
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作者 Wukui Tang Xiaofang Liu +6 位作者 Ya Li Yanhui Pu Yao Lu zhiming song Qiang Wang Ronghai Yu Jianglan Shui 《Nano Research》 SCIE EI CAS CSCD 2020年第2期447-454,共8页
Design and synthesis of highly efficient and cost-effective bifunctional catalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)remain a big challenge.Herein,a quaternary amorphous nanocompoun... Design and synthesis of highly efficient and cost-effective bifunctional catalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)remain a big challenge.Herein,a quaternary amorphous nanocompound Ni-Fe-P-B has been synthesized by a facile,scalable co-reduction method.The Ni-Fe-P-B exhibits high electrocatalytic activity and outstanding durability for both HER and OER,delivering a current density of 10 mA·cm^-2 at overpotentials of 220 and 269 mV,respectively.When loaded on carbon fiber paper(CFP)as a bifunctional catalyst,the Ni-Fe-P-B@CFP electrode requires a low cell voltage of 1.58 V to obtain 10 mA·cm^-2 for overall water splitting with negligible recession over 60 h.The excellent catalytic performances of Ni-Fe-P-B mainly benefit from the metal-metalloid combined composition modulation and the unique amorphous structure.This work provides new insights into the design of robust bifunctional catalysts for water splitting,and may promote the development of multicomponent amorphous catalysts. 展开更多
关键词 ELECTROCATALYST oxygen evolution reaction hydrogen evolution reaction water splitting AMORPHOUS
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冕环的自动检测算法和宽度统计分析
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作者 宋智明 李洪波 屈中权 《科学通报》 EI CAS CSCD 北大核心 2020年第8期704-717,共14页
冕环是日冕结构的重要组成部分,对冕环的尺寸及形态学的研究有助于我们更好地认识冕环的内部结构,同时也为进一步理解日冕构造、日冕活动区演化、日冕加热、日冕磁场和日冕等离子体属性等相关问题提供线索.本文以冕环的自动检测算法和... 冕环是日冕结构的重要组成部分,对冕环的尺寸及形态学的研究有助于我们更好地认识冕环的内部结构,同时也为进一步理解日冕构造、日冕活动区演化、日冕加热、日冕磁场和日冕等离子体属性等相关问题提供线索.本文以冕环的自动检测算法和基于自动检测算法的冕环宽度统计为研究目标,首先,提出了一种有效的基于匹配滤波和非锐化掩模增强的冕环自动检测算法.其次,使用所提出的算法对太阳动力学天文台(Solar Dynamics Observatory, SDO)的大气成像组件(Atmospheric Imaging Assembly, AIA)的图像和高分辨率日冕成像仪(Highresolution Coronal Imager, Hi-C)的图像中的冕环进行检测,并将检测结果与目前性能表现较优的算法--Oriented Coronal Curved Loop Tracing(OCCULT)的检测结果进行对比,以说明本文算法能检测到更多的冕环.进一步地,获得所有检测到的冕环的主轴和其局部方向,提取、计算和统计分析了它们的横切面轮廓宽度.最后,得到如下结论:(1)本文的冕环检测算法优于现存的性能较优的冕环检测算法OCCULT,因此可以进一步用于除了冕环宽度统计以外的其他与冕环相关的科学研究中;(2)与基于OCCULT算法的环宽统计结果相比,大样本统计结果更具有普适性,且证明了基于OCCULT算法的环宽统计结果对精细结构环宽样本的缺失导致其统计结果的不完整;(3)环宽统计结果进一步证明,相比于高分辨率的Hi-C, AIA/SDO的分辨率不足以分辨大部分的精细结构冕环. 展开更多
关键词 日冕 冕环 匹配滤波 检测 统计
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A comparative study of preventing postoperative tendon adhesion using electrospun polyester membranes with different degradation kinetics
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作者 zhiming song Bo Shi +4 位作者 Jianxun Ding Xiuli Zhuang Xiaonan Zhang Changfeng Fu Xuesi Chen 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第7期1159-1168,共10页
Complications arising from tendon injury include tendon sheath infection and peritendinous adhesion, in which tendon adhesion often leads to serious motor dysfunction. In this work, the electrospun membranes of poly(L... Complications arising from tendon injury include tendon sheath infection and peritendinous adhesion, in which tendon adhesion often leads to serious motor dysfunction. In this work, the electrospun membranes of poly(L-lactide)(PLA) and poly(ε-caprolactone)(PCL) with different degradation kinetics were used to investigate their efficacy for anti-adhesion toward Achilles tendon repair. Compared with the PCL membrane, the PLA sample showed a faster rate of degradation in 42 d, and all the degradation media(i.e., phosphate-buffered saline) maintained at a constant p H of around 7.4. Meanwhile, the superior biocompatibility of both the PLA and PCL membranes were proved by the in vitro cellular adhesion tests and in vivo histopathological assays. Simultaneously, the PLA membrane was more effective than the PCL sample in decreasing adhesion and promoting functional recovery. Furthermore, the experiment result was further confirmed by hematoxylin-eosin and Masson's trichrome staining, and type I collagen immunohistochemical analysis. All results revealed that the model treated with the electrospun PLA membrane was obviously better with regard to both anti-adhesion and tendon repair than that in the PCL membrane group. Considering the results of degradation and adhesion prevention efficacy, the electrospun polyester membranes, especially the PLA one, would be applied with fascinating potential in clinical prevention of postoperative tendon adhesion. 展开更多
关键词 ANTI-ADHESION Achilles tendon repair BIODEGRADABILITY electrospun membrane poly(L-lactide) poly(ε-caprolactone)
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