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Revealing the decomposition mechanisms of dislocations and metastableα’phase and their effects on mechanical properties in a Ti-6Al-4V alloy

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Journal of Materials Science & Technology 2022年第12期107卷 136-148页

作者： Jinlong Su xiankun Ji Jin Liu Jie Teng Fulin Jiang Dingfa Fu Hui Zhang College of Materials Science and engineering Hunan UniversityChangsha 410082China AeCC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

The metastableα’phase and dislocation characteristics(e.g.,density and constituents)are of vital importance for the mechanical responses of(α+β)titanium *** this work,to reveal the in-depth decomposition mechanisms of dislocations and metastableα’and their influences on mechanical properties in a Ti-6Al-4V(α+β)alloy,the thermal stability of different microstructures tailored by various cooling approaches were investigated utilizing scanning electron microscope,electron backscattered diffraction,transmission electron microscope and X-ray diffraction line profile *** results showed that the initial characteristics ofα’andαlaths and dislocation density were influenced by the cooling methods *** thermal stability of Ti-6Al-4V alloy increased with decreasing cooling *** improvement in thermal stability can be ascribed by the decrement in dislocations,partitioning of the alloying elements and grain orientations variation of theα’lath andα*** is also found that the plastic strain accommodation ofβ→α’transformation was dominated by *** stabilization annealing treatments,the,and dislocations simultaneously *** decomposition of dislocations and metastableα’phase during various stabilization annealing and the particular twins and stacking faults microstructures formed during quenching have a great influence on the properties of the studied Ti-6Al-4V alloy.

关键词： Titanium alloy Heat treatment Microstructure Mechanical properties Dislocation

Differentiation of Wheat Diseases and Pests Based on Hyperspectral Imaging Technology with a Few Specific Bands

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Phyton-International Journal of experimental Botany 2023年第2期92卷 611-628页

作者： Lin Yuan Jingcheng Zhang Quan Deng Yingying Dong Haolin Wang xiankun Du School of Information engineering Zhejiang University of Water Resources and Electric PowerHangzhou310018China School of Automation Hangzhou Dianzi UniversityHangzhou310018China Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China

Hyperspectral imaging technique is known as a promising non-destructive way for detecting plants diseases and *** most previous studies,the utilization of the whole spectrum or a large number of bands as well as the complexity of model structure severely hampers the application of the technique in *** a detection system can be established with a few bands and a relatively simple logic,it would be of great significance for *** study established a method for identifying and discriminating three commonly occurring diseases and pests of wheat,i.e.,powdery mildew,yellow rust and aphid with a few specific *** a comprehensive spectral analysis,only three bands at 570,680 and 750 nm were selected.A novel vegetation index namely Ratio Triangular Vegetation Index(RTVI)was developed for detecting anomalous areas on ***,the Support Vector Machine(SVM)method was applied to construct the discrimination model based on the spectral ratio *** validating results suggested that the proposed method with only three spectral bands achieved a promising accuracy with the Overall Accuracy(OA)of 83%.With three bands from the hyperspectral imaging data,the three wheat diseases and pests were successfully detected and discriminated.A stepwise strategy including background removal,damage lesions recognition and stresses discrimination was *** present work can provide a basis for the design of low cost and smart instruments for disease and pest detection.

关键词： Winter wheat diseases pests hyperspectral imaging discriminant analysis

Dual-wavelength pumped latticed Fermi-Pasta-Ulam recurrences in nonlinear Schrödinger equation

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Chinese Physics B 2024年第3期33卷 277-280页

作者：张倩姚献坤董恒 School of Physics Northwest UniversityXi'an 710127China Shaanxi key Laboratory for Theoretical Physics Frontiers Xi'an 710127China Peng Huanwu Center for Fundamental Theory Xi'an 710127China

We show that the nonlinear stage of the dual-wavelength pumped modulation instability(MI)in nonlinear Schrödinger equation(NLSe)can be effectively analyzed by mode truncation *** resulting complicated heteroclinic structure of instability unveils all possible dynamic trajectories of nonlinear ***,the latticed-Fermi-Pasta-Ulam recurrences on the modulated-wave background in NLSe are also investigated and their dynamic trajectories run along the Hamiltonian contours of the heteroclinic *** is demonstrated that there has much richer dynamic behavior,in contrast to the nonlinear waves reported *** novel nonlinear wave promises to inject new vitality into the study of MI.

关键词： modulation instability dual-wavelength pumps latticed-Fermi-Pasta-Ulam recurrences

Single-Atom Vacancy Doping in Two-Dimensional Transition Metal Dichalcogenides

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Accounts of Materials Research 2021年第8期2卷 655-668页

作者： xiankun Zhang Li Gao Huihui Yu Qingliang Liao Zhuo kang Zheng Zhang Yue Zhang Academy for Advanced Interdisciplinary Science and Technology School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Beijing Advanced Innovation Center for Materials Genome engineering Beijing Key Laboratory for Advanced Energy Materials and TechnologiesUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Beijing Advanced Innovation Center for Materials Genome engineering Beijing Key Laboratory for Advanced Energy Materials and Technologies and State Key Laboratory for Advanced Metals and MaterialsSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China

CONSPeCTUS:Faced with the growing quests of higher-performance chips,developing new channel semiconductors immune to short channel effects has become a realistic option for continuing Moore’s *** outstanding gate electrostatic capacitance,stable chemical properties,and suitable bandgap,two-dimensional(2D)transition metal dichalcogenides(TMDCs)are considered as potential candidates for next-generation channel ***,the practical applications of 2D TMDCs are severely limited by stable,precise,and controllable doping technologies,due to their ultrathin body and dangling bond-free *** to three-dimensional semiconductors,donors in 2D semiconductors need larger ionization energy which can be attributed to the reduced screening of Coulomb interaction and the larger bandgap induced by quantum *** by the ultrathin body of 2D TMDCs and the strong film−substrate charge transfer,typical silicon-based substitutional doping technology encounters some headache difficulties in 2D TMDCs and hardly achieves high-concentration *** other two doping technologies also cannot take on this task either;local gate electrostatic doping cannot leave the aid of the external electric *** surface charge transfer doping of molecule adsorbents behaves unstably(e.g.,thermal desorption)or ineffectively modifies the original electronic ***,single-atom vacancies can effectively and precisely adjust the carrier concentration of 2D TMDCs and significantly enhance their ***,clarifying the work rules and function mechanism of single-atom vacancy doping in 2D TMDCs is beneficial in creating a brand-new optimization strategy of electrical properties and overcoming the technical obstacles of the“lab-to-fab”transition for their practical applications in high-performance electronics and *** this Account,we summarize the state-of-the-art progress in single-atom vacancy doping in 2D TMDCs and highlight t

关键词： doping precise electrostatic

Topographic species-habitat associations of tree species in a heterogeneous tropical karst seasonal rain forest, China

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Journal of Plant ecology 2017年第3期10卷 450-460页

作者： Yili Guo Bin Wang Azim U.Mallik Fuzhao Huang Wusheng Xiang Tao Ding Shujun Wen Shuhua Lu Dongxing Li Yunlin He xiankun Li Guangxi key Laboratory of Plant Conservation and Restoration ecology in karst Terrain Guangxi Institute of BotanyGuangxi Zhuang Autonomous Region and Chinese Academy of SciencesGuilin 541006China Guangxi Youyiguan Forest ecosystem National Research Station Pingxiang 532600China Department of Biology Lakehead UniversityThunder BayOntario P7B 5E1Canada

Aims Tropical and subtropical karst forests of south China are under increas-ing pressure from over-exploitation causing widespread habitat degra-dation and biodiversity *** research has demonstrated that topography,as a proxy for resource availability,plays an important role in shaping tree species distributions in tropical ***,the association between growth stages and habitats types has not been considered in this *** aim was to examine the differences among different habitat types to determine whether tree species show similar species-habitat associations at young and mature life *** We used multivariate regression tree analysis to examined species-habitat associations among eight topographically defined *** results were tested with a torus-translation test and canonical correspondence analysis(CCA)for 74 species in a 15 ha karst tropi-cal seasonal rain forest at the Nonggang National Natural Reserve in south *** considered two life stages(young and mature)of trees species that showed a positive association with *** Findings We found marked differences in community characteristics and number of associations among the eight *** the 74 species subjected to torus-translation test,63 had significant positive and 70 had significant negative associations with one or more of the eight *** associations were more frequent in higher elevation habitats and negative associations were more frequent in lower eleva-tion *** suggests that edaphic and hydrological variation related to topography play important roles in habitat partitioning in heterogeneous karst *** the 63 tree species with significant positive associations to at least one habitat,40 of them had the same positive association at young and mature life *** CCA revealed that the six topographic variables considered had consistent relation-ships with species distribution among all individuals and the

关键词： multivariate regression tree torus-translation test canonical correspondence analysis niche differentiation dispersal limitation environmental heterogeneity

解析法-Nelder Mead单纯形算法确定太阳电池参数

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农业工程学报 2014年第6期30卷 97-106页

作者：高献坤姚传安高向川余泳昌河南农业大学农业部农村可再生能源新材料与装备重点实验室郑州450002 郑州大学信息工程学院郑州450001

光伏发电系统的设计计算、性能评估及优化控制要求快速、准确的确定太阳电池模型参数。针对太阳电池单、双二极管模型参数辨识问题,该文提出一种基于解析法和Nelder Mead单纯形法重启策略的A-bcNM混合算法。先用实测I-V曲线上的部分关... 详细信息

光伏发电系统的设计计算、性能评估及优化控制要求快速、准确的确定太阳电池模型参数。针对太阳电池单、双二极管模型参数辨识问题,该文提出一种基于解析法和Nelder Mead单纯形法重启策略的A-bcNM混合算法。先用实测I-V曲线上的部分关键点计算合成参数,再以单二极管模型近似解析式快速定位搜索始点,最后在边界范围内利用Nelder Mead单纯形算法的重启策略最小化实测数据与模拟结果之间的均方根误差,以提高拟合精度及参数解的质量。MATLAB环境下,利用2种典型太阳电池的实测数据对A-bcNM算法的有效性进行了测试和验证。与已有的其他算法相比,A-bcNM算法收敛速度快,计算量小,辨识精度高,可快速、准确的确定单、双二极管模型参数,为识别太阳电池的工作特性提供了一种有效方法。

关键词：太阳电池模型参数单二极管双二极管 NelderMead单纯形算法

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基于小波包能量法的简支梁损伤仿真识别研究

系统仿真学报 2019年第6期31卷 1201-1207页

作者：刘习军陶宪坤张素侠天津大学机械工程学院

通过ANSYS软件建立简支梁模型,用MATLAB软件对其位移响应进行小波包分析。采用小波包能量曲率差作为指标进行损伤识别,研究了损伤数量、损伤位置、损伤程度、测点疏密和移动荷载速度等参数对简支梁桥损伤结果的影响,提出分步识别方法,... 详细信息

通过ANSYS软件建立简支梁模型,用MATLAB软件对其位移响应进行小波包分析。采用小波包能量曲率差作为指标进行损伤识别,研究了损伤数量、损伤位置、损伤程度、测点疏密和移动荷载速度等参数对简支梁桥损伤结果的影响,提出分步识别方法,解决稀疏测点情况下的损伤识别问题,并将小波包能量曲率差归一化,研究该方法对噪声的鲁棒性。结果表明小波包能量法能有效、准确地识别梁的损伤。

关键词：简支梁小波包能量损伤模拟损伤识别

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交错型PFC升压控制开关电源电路设计

价值工程 2011年第26期30卷 40-41页

作者：赵先堃西安铁路职业技术学院西安710014

本文分析和设计了一种基于飞思卡尔公司的MC56800/e为控制芯片的零电压ZVS准谐振开关模式电源。其前级采用功率因数校正(PFC)技术,后级采用全桥逆变、和全桥整流技术,并在高频开关变压器的一次侧采用准谐振软开关技术。实验结果表明,该... 详细信息

本文分析和设计了一种基于飞思卡尔公司的MC56800/e为控制芯片的零电压ZVS准谐振开关模式电源。其前级采用功率因数校正(PFC)技术,后级采用全桥逆变、和全桥整流技术,并在高频开关变压器的一次侧采用准谐振软开关技术。实验结果表明,该电路达到了设计标准,有效提高了装置的能效。

关键词：开关电源SMPS 有源功率因数校正 DC-DC转换器

某预应力混凝土管桩生产企业职业病危害分析与控制措施探讨

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职业卫生与应急救援 2018年第6期36卷 541-543+546页

作者：于先坤杨洪华唯金属矿产资源高效循环利用国家工程研究中心有限公司中钢集团马鞍山矿山研究院有限公司金属矿山安全与健康国家重点实验室安徽欣创节能环保科技股份有限公司

[目的]通过分析某预应力混凝土管桩生产企业管桩生产过程中存在的职业病危害因素、危害程度以及职业健康体检中存在的问题,探讨相应的工程控制措施和职业卫生管理工作方面防护措施,为该行业职业健康监护和职业卫生管理提供依据。[方法]... 详细信息

[目的]通过分析某预应力混凝土管桩生产企业管桩生产过程中存在的职业病危害因素、危害程度以及职业健康体检中存在的问题,探讨相应的工程控制措施和职业卫生管理工作方面防护措施,为该行业职业健康监护和职业卫生管理提供依据。[方法]依据GBZ 159-2004采样要求,结合职业卫生调查法、检测检验法、工程分析法对企业管桩生产现场的职业病危害因素进行识别、分析和评价。[结果]管桩生产过程中存在的职业病危害因素主要有粉尘(其他粉尘、煤尘、电焊烟尘)、锰及其无机化合物、一氧化碳、噪声、手传振动、高温等。噪声、手传振动检测结果超标严重,A车间、e车间和大桩车间的拌和机手、布料工、风炮手、张拉机手、离心机手、滚焊机手以及A车间、e车间的行车工岗位40 h等效声级[86.4～108.1 dB(A)]均超过国家标准;风炮手接触手传振动4 h等能量频率计权振动加速度值为18～24 m2/s,均超过国家标准。粉尘、CO、锰及其无机化合物检测浓度均符合国家标准。职业健康体检开展力度不够,存在缺检、漏检,人员体检率较低等现象。缺少职工上岗前、离岗时的职业健康检查资料。[结论]现场职业病危害因素(噪声、手传振动)超标严重,职业健康体检工作存在较多问题,企业须加强现场工程防护和个体防护措施,并应按照GBZ 188-2014要求,进一步完善一线职工的职业健康监护工作。

关键词：预应力混凝土管桩职业病危害噪声手传振动职业健康