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融合加窗和自适应加权引导滤波改进的Canny算法

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化工自动化及仪表 2024年第1期51卷 86-91页

作者：郝霜李金凤翟迅步沈阳化工大学信息工程学院

针对Canny算法滤波过程中图像细节部分缺失和无法有效去除噪声,并且无法动态识别图像边缘的问题,提出一种融合加窗和自适应加权引导滤波的Canny算法。该算法对Canny算法做出两点改进:一是使用加窗滤波器对图像进行处理,有效滤除噪声,然... 详细信息

针对Canny算法滤波过程中图像细节部分缺失和无法有效去除噪声,并且无法动态识别图像边缘的问题,提出一种融合加窗和自适应加权引导滤波的Canny算法。该算法对Canny算法做出两点改进:一是使用加窗滤波器对图像进行处理,有效滤除噪声,然后对图像进行数学形态学滤波处理,有效增强图像边缘;二是引入分段权值模型对引导滤波算法的正则化参数自适应修正,使其能够根据梯度信息区分边缘和非边缘,从而达到动态识别图像边缘的效果。相比传统Canny算法,改进算法处理后的信噪比提高了1.05~5.22 dB,品质因数提高了0.16~0.35。实验结果表明:改进算法能有效滤除椒盐噪声,识别出比较清晰和完整的边缘。

关键词： Canny算法边缘检测加窗滤波器数学形态学自适应加权引导滤波

Research on electromagnetic relay's dynamic characteristics disturbed by uniform static magnetic field

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第4期9卷 577-582页

作者： Guo-fu zhai Qi-ya WANG Wan-bin ren Military Apparatus Research Institute Harbin Institute of Technology Harbin 150001 China

Electromagnetic relay is a widely used apparatus which usually works in a magnetic disturbance environment. To evaluate its electromagnetic compatibility (EMC) in a static magnetic field, dynamic characteristics of a clapper relay in a uniform static magnetic field situation based on the finite element method (FEM) is studied. Influences of the magnetic field on dynamic parameters (delay time, pick-up time, end pressure, and final velocity) as well as a situation in which the relay cannot function normally are analyzed. Simulation reveals that the external magnetic field which weakens the relay’s air-gap field has a greater influence on the relay’s dynamic parameters than the one strengthening the field. The validity of the simulation is verified by measured results of coil current and armature displacement.

关键词： Dynamic characteristics Uniform static magnetic field Electromagnetic relay Finite element method (FEM) Electromagnetic compatibility (EMC)

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新工科背景下“工程化学”课程思政教学探索

廊坊师范学院学报（自然科学版） 2024年第1期24卷 121-123,128页

作者：王爽赵芸任朝科廊坊师范学院河北廊坊065000 天津中学天津300384

以“工程化学”课程为例,以三星堆发掘、火神山雷神山医院建设的环保措施、港珠澳大桥和杭州湾跨海大桥的防腐蚀方案为切入点,将专业知识与思政元素结合,从文化自信、生命意识、绿色发展理念、工匠精神、创新精神5个方面进行课程思政内... 详细信息

以“工程化学”课程为例,以三星堆发掘、火神山雷神山医院建设的环保措施、港珠澳大桥和杭州湾跨海大桥的防腐蚀方案为切入点,将专业知识与思政元素结合,从文化自信、生命意识、绿色发展理念、工匠精神、创新精神5个方面进行课程思政内容设计,将思想政治教育工作贯穿教学全过程,充分发挥课堂主阵地作用,为理工科专业课程思政建设提供实践经验。

关键词：课程思政新工科工程化学

Does persistence of showy calyces in Limonium leptolobum enhance pollinator attraction?

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Journal of Plant Ecology 2015年第2期8卷 182-186页

作者： Ai-Qin Zhang shuang He Ya-Xin zhai shuang-Quan Huang College of Life Science and Technology Xinjiang UniversityNo.14 Victory AvenueUrumqi 830046China School of Life Sciences Central China Normal University152 Luoyu AvenueHongshan DistrictWuhan 430079China

Aims The calyx,the outermost whorl of a flower(usually green),has been considered to function to protect *** some species,how-ever,calyces are colorful and retained during seed *** species have been exploited as cut flower crops because the calyces persist for several months after the corolla has *** explore the adaptive significance of the persistent calyx in a desert plant Limonium leptolobum,we ask whether persistence of caly-ces can enhance pollinator attraction by enlarging floral displays,increasing reproductive success in this self-incompatible *** The yellow flower of *** lasted 1-2 days but its white,membranous calyx extended fully after the corolla closed,and per-sisted for over 2 months in the field,making hundreds of‘showy flowers’on one *** examine the ecological function of calyces,we test the pollinator attraction *** an experi-mental population,we compared the difference in visit frequency and visitor behavior between intact inflorescences and inflores-cences with their calyces removed on the same individual *** findingsin four experimental plots four types of floral visitors were observed including bees,butterflies,syrphid flies and day-flying *** significant preference was observed between calyx-free and intact inflorescences for both first arrivals and total visit frequency of all types of floral visitors,indicating that the persistence of calyces did not make plants more attractive to potential *** pollina-tor attraction hypothesis for the showy calyces was not supported by the current *** the calyx in this desert plant helps seed development or has other functions needs further study.

关键词： Limonium leptolobum calyx floral traits pollinator preference advertisement ecological function

理化复合参数和神经网络结合的冬小麦长势遥感监测

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农业工程学报 2024年第14期40卷 91-99页

作者：马爽张卓然张钧泳骆秀斌高瑞任嘉敏侯学会山东省农业科学院农业信息与经济研究所济南250100 山东师范大学地理与环境学院济南250358

准确、及时地监测区域作物长势状况对农业规划和政策的制定与调整具有重要的意义。遥感技术作为一种收集大面积作物长势信息的有效手段,正日益受到关注。为提高冬小麦长势遥感监测的准确性和全面性,该研究基于田间实测的冬小麦拔节期地... 详细信息

准确、及时地监测区域作物长势状况对农业规划和政策的制定与调整具有重要的意义。遥感技术作为一种收集大面积作物长势信息的有效手段,正日益受到关注。为提高冬小麦长势遥感监测的准确性和全面性,该研究基于田间实测的冬小麦拔节期地上鲜生物量(aboveground fresh biomass,AFB)、叶面积指数(leaf area index,LAI)、叶片叶绿素相对含量(soil and plant analyzer development,SPAD)和叶片氮含量(leaf nitrogen content,LNC)4种生长相关理化参数,利用熵值法获取各参数权重构建冬小麦理化复合参数(physico-chemical composite parameter,PCCP)。利用显著性检验和籽粒产量数据分析复合参数在量化冬小麦长势方面的性能。然后,以Sentinel-2A作为数据源,分析不同遥感指数与LAI、SPAD、AFB、LNC和PCCP的相关性。选取相关性较高的遥感指数作为反向传播(back propagation,BP)人工神经网络(artificial neural networks,ANN)的输入,建立冬小麦长势遥感监测模型,对PCCP进行估计。评价模型精度并用于监测研究区冬小麦长势分布特征。赋权结果表明,作物物理参数的权重大于生化参数,其中LAI的权重最大,为0.387,AFB和SPAD次之,LNC的权重最小,为0.105;PCCP性能评估结果表明,与单一理化参数相比,PCCP值能更好地揭示作物长势状况的差异,其与最终籽粒产量的相关性更好,决定系数提高0.035~0.468,均方根误差减少46.2~520.0 kg/hm^(2);在遥感监测过程中,PCCP比单一理化参数有更好的应用潜力,BP-ANN长势遥感监测模型模拟PCCP精度较高,在测试集中决定系数为0.830,均方根误差为0.080;研究区冬小麦总体长势稳定且分布集中,呈现"中部差,南北好"的空间分布特征。因此,构建作物理化复合参数用于量化作物长势是提高长势监测可靠性和准确性的一种有效方式,可为冬小麦田间管理提供科学依据,服务于发展智慧农业和建设农业强国的战略需求。

关键词：遥感人工神经网络长势监测理化复合参数冬小麦

Fabrication of nanoporous Ni and NiO via a dealloying strategy for water oxidation catalysis

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Journal of Energy Chemistry 2020年第11期29卷 125-134页

作者： Xiangrong ren Yiyue zhai Qi Zhou Junqing Yan Shengzhong Liu Key Laboratory of Applied Surface and Colloid Chemistry Ministry of EducationShaanxi Engineering Lab for Advanced Energy TechnologySchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710119ShaanxiChina State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050GansuChina Materials Science and Engineering College Lanzhou University of TechnologyLanzhou 730050GansuChina

Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanoporous Ni by a method of combined rapid solidification and chemical dealloying. Subsequently,nanoporous Ni O was obtained via heating treatment, the macropore and skeleton sizes of the NiO originated from Ni10Al90 alloy are 100–300 nm and 80–200 nm, respectively. Benefiting from the multi-stage nanoporous structure and high specific surface area, the nanoporous NiO demonstrates an outstanding OER, reaching 20 mA cm-2 at an overpotential of 356 mV in 1 M KOH. The corresponding Tafel slope and apparent activation energy are measured to be 76.73 mV dec-1 and 29.0 kJ mol-1, respectively. Moreover,kinetic analysis indicates that the Ni O catalyst shows pseudocapacitive characteristics, and the improved current is attributed to the high-rate pseudocapacitive behavior that efficiently maintains increased nickel redox cycling to accelerate the reaction rates. After 1000 cycles of voltammetry, the overpotential of the NiO decreases by 22 mV(j = 10 mA cm-2), exhibiting excellent stability and durability.

关键词： Rapid solidification Dealloying Nanoporous Ni Electrocatalyst OER

Fast Carrier Selection of JPEG Steganography Appropriate for Application

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Tsinghua Science and Technology 2020年第5期25卷 614-624页

作者： Weixiang ren Yibo Xu Liming zhai Lina Wang Ju Jia the Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of EducationWuhan UniversityWuhan 430000China the School of Cyber Science and Engineering Wuhan UniversityWuhan 430000China Micropattern Co.Ltd. Wuhan 430000China

In recent years,the improvement of the security of steganography mainly involves not only carrier security but also distortion *** the actual environment,the existing method of carrier selection is limited by its complex algorithm and slow running speed,making it not appropriate for rapid *** study proposes a method for selecting carriers and improving the security of *** images are decompressed to spatial *** correlation coefficients between two adjacent pixels in the horizontal,vertical,counter diagonal,and major diagonal directions are *** mean value of the four correlation coefficients is used to evaluate the security of each JPEG *** images with low correlation coefficients are considered safe carriers and used for embedding in our *** experimental results indicate that the stego images generated from the selected carriers exhibit a higher anti-steganalysis capability than those generated from the randomly selected *** the premise of the same security level,the images with low correlation coefficients have a high *** algorithm has a very fast running speed,and the running time of a 2048×2048 image is less than 1 s.

关键词： steganography steganalysis carrier JPEG correlation coefficients

A Sample-Efficient Actor-Critic Algorithm for Recommendation Diversification

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Chinese Journal of Electronics 2020年第1期29卷 89-96页

作者： LI shuang YAN Yanghui ren Ju ZHOU Yuezhi ZHANG Yaoxue Department of Computer Science and Technology Tsinghua University

Diversifying recommendation results gains benefits from satisfying user’s existing interests as well as exploring novel information needs. Recently proposed Monte-Carlo based reinforcement learning method suffers from sample inefficiency, large variance, and even failing to perform well in large action space. We propose a novel actor-critic reinforcement learning algorithm for recommendation diversification in order to solve the above mentioned problems. The actor acts as the ranking policy, while the introduced critic predicts the expected future rewards of each candidate action. The critic target is updated by full Bellman equation and the actor network is optimized using expected gradient in the whole action space. To further stabilize and improve the performance, we also add policy-filtered critic supervision loss. Experiments on MovieLens dataset well demonstrate the effectiveness of our approach over multiple competitive methods.

关键词： Recommender system Diversity Reinforcement learning Actor-critic

Ageing Hardening Mechanism and Corrosion Resistance in the Fe65Cr13Cu3(CoMnMoNiAlTi)19 Medium-Entropy Stainless Alloy

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Acta Metallurgica Sinica(English Letters) 2021年第11期34卷 1601-1608页

作者： Ben-Qi Xu Hui Zhang Dong Ma Qun-shuang Ma Li-zhai Pei Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials(Ministry of Education) Anhui University of Technology243002Ma'anshanChina School of Materials Science and Engineering Anhui University of TechnologyMa'anshan 243002China

The ageing hardening mechanism of a newly designed Fe65Cr13Cu3(CoMnMoNiAlTi)19 medium-entropy stainless alloy(ME-SA)with a simple bcc solid solution matrix was *** kind of ME-SA possessed a higher ageing hardness of approximately 584 HV and higher compressive stress and corrosion resistance than those of the conventional precipitation hardening stainless steel 17-4 PH(Cr17Ni4Cu4 Nb),which has comparable compressive *** well-dispersed B2-ordered phase in the cast state transformed to a D03 crystal structure with a higher ordering degree and reduced the precipitate size after ageing at 500℃,thus promoting a great ageing hardening effect.

关键词： Medium-entropy stainless alloy Ordered phase transition Aging hardening Corrosion resistance