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基于小波和形态学的自然地面背景红外目标检测方法

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信息与控制 2004年第1期33卷 107-111页

作者：温佩芝史泽林于海斌中国科学院沈阳自动化研究所辽宁沈阳110016

本文采用小波变换和形态Top Hat滤波相结合的方法抑制红外图像的混合噪声及大面积的背景干扰 ,减少图像模糊和增强目标 ;通过选择适当的结构元素进行系列形态组合运算 ,去掉虚警点而获得少量候选目标 ;搜索局部极大值并确定阈值 ,分离... 详细信息

本文采用小波变换和形态Top Hat滤波相结合的方法抑制红外图像的混合噪声及大面积的背景干扰 ,减少图像模糊和增强目标 ;通过选择适当的结构元素进行系列形态组合运算 ,去掉虚警点而获得少量候选目标 ;搜索局部极大值并确定阈值 ,分离出真正的目标 .实验结果表明 ,该方法能有效检测和分割出低信噪比复杂自然背景红外图像中的目标 .

关键词：形态学小波变换图像分割红外目标检测虚警点红外探测系统

Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

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Science China Chemistry 2025年

作者： Shuai Zhang pei-zhi Liu Yan-Bo Li Qi Zhang Jun-Zhao Xiao Yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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托勒密时期的埃及王权形象塑造与身份认同

史学集刊 2025年第1期 109-120页

作者：史海波李智琳吉林大学历史文化学院世界史系吉林长春130012

作为外族统治者的托勒密王朝历代国王,通过采用埃及传统王权符号、沿袭前朝本土法老的外观和王名等方式,在具象层面构建了正统的埃及王权形象。同时,托勒密统治者对埃及本土宗教和仪式表现出虔敬的态度,并以此塑造合法的埃及法老身份,... 详细信息

作为外族统治者的托勒密王朝历代国王,通过采用埃及传统王权符号、沿袭前朝本土法老的外观和王名等方式,在具象层面构建了正统的埃及王权形象。同时,托勒密统治者对埃及本土宗教和仪式表现出虔敬的态度,并以此塑造合法的埃及法老身份,包括神化自身,强调神圣世系的继承,以及宣传恢复国家秩序和维护传统宗教仪式等方式。然而从现实情况来看,托勒密统治者更为重视希腊君主的身份,法老身份只是他们用于维持统治的宣传工具。由于现实中经济、阶层和种族矛盾的存在,包括祭司、权贵和平民在内的埃及臣民对外族法老身份的认同也相对有限。在征服与统治的背景下,不同文明之间很难形成完全的互相认同。

关键词：托勒密时期古埃及王权形象身份认同

Preparation of Porous Polylactide Microspheres and Their Application in Tissue Engineering

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Chinese Journal of Polymer Science 2018年第6期36卷 712-719页

作者： Xu-Dong shi pei-Jian Sun zhi-Hua Gan Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China The GAS Key Laboratory of Engineering Plastics Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China State Key Laboratory of Organic-inorganic Composites College of Life Science and TechnologyBeijing University of Chemical TechnologyBeijing 100029China

In this study, porous polylactide（PLA） microspheres with different structures were prepared through the multiple emulsion solvent evaporation method. By changing organic solvents（ethyl acetate and chloroform） and adding effervescent salt NH4 HCO3 in the inner water phase, microspheres with porous capsular, matrix, microcapsular and multivesicular structures were prepared. The protein encapsulation and release, and the cell growth behavior of porous microspheres were further explored. Under the same inner water phase, microspheres prepared with chloroform had higher protein encapsulation efficiency and less protein release rate as compared with those prepared with ethyl acetate. Cell experiments showed that the relatively rough surface of microspheres prepared with chloroform was more favorable for the cell growth in comparison with the smooth surface of microspheres prepared with ethyl acetate. This study shows a simple and effective method to control the protein release and cell growth behaviors of polymer microspheres by tuning their porous structure.

关键词： Polylactide Porous microspheres Drug release Cell Tissue engineering

Effects of plant species coexistence on soil enzyme activities and soil microbial community structure under Cd and Pb combined pollution

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Journal of Environmental Sciences 2010年第7期22卷 1040-1048页

作者： Yang Gao pei Zhou Liang Mao Yueer zhi Chunhua Zhang Wanjun shi School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 China School of Agriculture and Biology Shanghai Jiaotong University Shanghai 200240 China Key Laboratory of Urban Agriculture (South) Ministry of Agriculture Shanghai 200240 China

The relationship between plant species coexistence and soil microbial communities under heavy metal pollution has attracted much attention in ecology. However, whether plant species coexistence could offset the impacts of heavy metal combined pollution on soil microbial community structure and soil enzymes activities is not well studied. The modified ecological dose model and PCR-RAPD method were used to assess the effects of two plant species coexistence on soil microbial community and enzymes activities subjected to Cd and Ph combined stress. The results indicated that monoculture and mixed culture would increased microbe populations under Cd and Pb combined stress, and the order of sensitivity of microbial community responding to heavy metal stress was： actinomycetes 〉 bacteria 〉 fungi. The respirations were significantly higher in planted soil than that in unplanted soil. The plant species coexistence could enhance soil enzyme activities under Cd and Pb combined. Furthermore, planted soil would be helpful to enhance soil genetic polymorphisms, but Cd and Pb pollution would cause a decrease on soil genetic polymorphisms. Mixed culture would increase the ecological dose 50% （ED50） values, and the ED50 values for soil enzyme activities decreased with increasing culture time. The dehydrogenase was most sensitive to metal addition and easily loses activity under low dose of heavy metal. However, it was difficult to fully inhibit the phoshpatase activity, and urease responded similarly with phosphatase.

关键词： ecological dose enzyme activities DNA RAPD heavy metal

Fabrication of N,S co-doped carbon immobilized high-density Co single atoms toward electro-oxidation of organic sulfides with water as feedstock

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Nano Research 2023年第5期16卷 6593-6600页

作者： pei Zhu Wen-Xiong shi Ying Wang zhi-Ming Zhang Lina Li Changhua An Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion Tianjin Key Laboratory of Advanced Functional Porous MaterialsInstitute for New Energy Materials&Low-Carbon TechnologiesTianjin University of TechnologyTianjin 300384China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Department of Chemistry The Chinese University of Hong KongShatinNew TerritoriesHong Kong 999077China

Development of high-density single atoms site(SAs)electrocatalysts is highly desirable due to their extraordinary catalytic ***,their synthesis is still challenging and their anticorrosion capacities in electrolyte(particularly in acidic electrolyte)are ***,we have constructed N,S co-doped carbon to anchor~10 wt.%Co SAs(Co-SAs/NSC)via a novel polymerization–sulfurization–pyrolysis strategy toward selective electro-oxidation of thioethers in acidic *** asobtained Co SAs has a coordination geometry of Co-S_(2)N_(4),exhibiting excellent electrocatalytic activity and robust *** a low potential of 1.40 V *** hydrogen electrode(RHE),the conversion rate of thioethers over Co-SAs/NSC reaches 99.7%with 100%selectivity and 100%Faraday efficiency(FE)for producing sulfoxide,which is higher than the commercial Pt electrode and the reported state-of-the-art *** calculations and experiments reveal that the Co-S_(2)N_(4)structure endows the outstanding electro-oxidation activity of Co SAs through significantly promoting desorption of the *** work presents a convenient strategy to build high-performance SAs catalysts for the resourceful use of sulfur-containing pollutants.

关键词： single-atom cobalt high density selective oxidation electrocatalysis

基于改进YOLOv8的自动驾驶场景目标检测算法

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计算机工程与应用 2025年第1期61卷 131-141页

作者：杨磊陈艳菲李海鸣石教兴安培武汉工程大学光学信息与模式识别湖北省重点实验室武汉430205 武汉工程大学电气信息学院武汉430205 华中科技大学电子信息与通信学院武汉430074

针对自动驾驶场景遮挡目标和小目标检测困难问题,提出了FAN-YOLOv8n自动驾驶检测算法。设计了特征感受野融合模块(EFFVM),增强模型主干部分对局部特征的提取,提高模型对遮挡目标的检测能力;在模型头部增加了更浅特征层P2的检测头,提高... 详细信息

针对自动驾驶场景遮挡目标和小目标检测困难问题,提出了FAN-YOLOv8n自动驾驶检测算法。设计了特征感受野融合模块(EFFVM),增强模型主干部分对局部特征的提取,提高模型对遮挡目标的检测能力;在模型头部增加了更浅特征层P2的检测头,提高模型对于小目标的检测效果;在模型颈部设计了特征指导模块(FGM)来融合浅层和深层的特征信息,使得两层之间能够更好地进行特征交互,让模型更关注细粒特征。提出了特征层融合模块(FLFM),融合多尺度特征层并进行特征增强,使模型能够自适应不同尺度目标的检测。实验结果表明,在SODA10M数据集和部分BDD100K数据集上,改进模型的mAP0.5对比原始YOLOv8n模型提升了7个百分点和6.5个百分点,适用于实际自动驾驶检测任务。

关键词：自动驾驶 YOLOv8n 小目标遮挡目标

Microstructure, Interface, and Properties of Multilayered CrN/Cr_2O_3 Coatings Prepared by Arc Ion Plating

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Journal of Materials Science & Technology 2014年第12期30卷 1193-1201页

作者： Chang-Ming shi Tie-Gang Wang zhi-Liang pei Jun Gong Chao Sun State Key Laboratory for Corrosion and Protection (SKLCP) Institute of Metal Research Chinese Academy of Sciences

There has been much interest in developing multilayered or nanolayered physical vapor deposition（PVD） coatings identified as a group of promising protective coatings for their excellent mechanical properties and corrosion resistance. In this study, the multilayered Cr N/Cr2O3 coatings with different bilayer periods（L） were synthesized on the polished high speed steel substrates from a Cr target with the alternative atmosphere of pure nitrogen and pure oxygen by arc ion plating（AIP） technique. The results revealed that the microstructure,morphologies and properties of the multilayered coatings were strongly influenced by the bilayer period（L）.There were two kinds of interfaces in the multilayered Cr N/Cr2O3coatings： the sharp ones and the blurry ones. With reducing the value of L, the macro-particles densities decreased gradually, whereas the coating microhardness, adhesive strength and wear resistance first increased, and then decreased slightly or remained stable as the bilayer period L 〈 590 nm. The multilayered Cr N/Cr2O3 coating with the bilayer period L of 590 nm possessed the best comprehensive properties, namely the highest microhardness, the strongest adhesion, and the lowest wear rate.

关键词： Cr2O3/CrN Multilayered coating Arc ion plating Interface Mechanical properties Wear

Effects of the Thickness Ratio of CrN vs Cr_2O_3 Layer on the Properties of Double-layered CrN/Cr_2O_3 Coatings Deposited by Arc Ion Plating

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Journal of Materials Science & Technology 2014年第5期30卷 473-479页

作者： Chang-Ming shi Tie-Gang Wang zhi-Liang pei Jun Gong Chao Sun State Key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences

In this study, CrN/Cr2O3 double-layered coatings with various thickness ratios of CrN vs Cr2O3 layer were prepared by arc ion plating technology. The influences of the thickness ratio of CrN vs Cr2O3 layer on the microstructural characteristics as well as the mechanical and tribological properties of the CrN/Cr2O3 doublelayered coatings were investigated. The corresponding mechanisms were also discussed. The results indicated that the insertion of CrN layer between the Cr2O3 layer and substrate can effectively decrease the internal stress level of the coating. With increasing the thickness ratio of CrN vs Cr2O3 layer, the surface roughness of double-layered coatings decreased gradually, which had a certain influence on the friction coefficient. In addition, the microhardness also declined gradually, the adhesive strength almost increased linearly, whereas the wear rate declined firstly and then increased slightly. As the thickness ratio was 2：1, the double-layered coating exhibited the best wear resistance.

关键词： Cr2O3/CrN Double-layered coating Thickness ratio Arc ion plating Mechanical property Wear