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基于实际功率曲线阈值筛选的风电机组偏航误差算法研究

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动力工程学报 2024年第8期44卷 1196-1204,1225页

作者：吕松灏刘向民方超丁士发余从极马永鑫上海发电设备成套设计研究院有限责任公司上海200240 国家电投集团江苏电力有限公司南京210008 远景能源有限公司江苏无锡214000

现有风电机组偏航误差评估方法多借助激光雷达或依赖长期(大于3个月)运行数据。针对新机组首次维护前的短期运行数据偏航误差计算问题,提出一种基于实际功率曲线阈值筛选的偏航误差算法。首先,通过Bin法求解机组实际功率曲线,利用实际... 详细信息

现有风电机组偏航误差评估方法多借助激光雷达或依赖长期(大于3个月)运行数据。针对新机组首次维护前的短期运行数据偏航误差计算问题,提出一种基于实际功率曲线阈值筛选的偏航误差算法。首先,通过Bin法求解机组实际功率曲线,利用实际功率曲线阈值方法在无需机舱传递函数(NTF)的条件下剔除可能降低计算准确度的数据;其次,对筛选后的数据集做风速分仓,利用区间均值法求解各风仓代表偏航误差;最后,使用风速加权法求解偏航误差。在江苏某陆上风电场的实践应用表明,所提出的算法针对短期和长期运行数据均可获得有效的偏航误差计算结果。

关键词：风力发电偏航误差数据处理功率曲线

Polynomial-Time Assignment-Based Cell Association with Generic Utility Functions

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China Communications 2022年第9期19卷 214-228页

作者： Lusheng Wang chao fang Hai Lin Min Peng Caihong Kai Key Laboratory of Knowledge Engineering with Big Data Ministry of Education.School of Computer Science and Information EngineeringHefei University of TechnologyHefei 230601China Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education.School of Cyber Science and EngineeringWuhan UniversityWuhan 430072China

Cell association is a significant research issue in future mobile communication systems due to the unacceptably large computational time of traditional *** article proposes a polynomial-time cell association scheme which not only completes the association in polynomial time but also fits for a generic optimization objective *** the one hand,traditional cell association as a non-deterministic polynomial(NP)hard problem with a generic utility function is heuristically transformed into a 2-dimensional assignment optimization and solved by a certain polynomial-time algorithm,which significantly saves computational *** the other hand,the scheme jointly considers utility maximization and load balancing among multiple base stations(BSs)by maintaining an experience pool storing a set of weighting factor values and their corresponding *** an association optimization is required,a suitable weighting factor value is taken from the pool to calculate a long square utility matrix and a certain polynomial-time algorithm will be applied for the *** with several representative schemes,the proposed scheme achieves large system capacity and high fairness within a relatively short computational time.

关键词： mobile communication system 2-dimensional assignment problem hungarian algorithm fairness cell association

Effects of BN content on the mechanical properties of nanocrystalline 3Y-TZP/Al_(2)O_(3)/BN dental ceramics

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1854-1860页

作者： Lei Zhou Yan-fang Zhang Pan Yi Ying Wen chao-fang Dong Li-min Meng Se-fei Yang Medical School of Chinese PLA Beijing 100853China Department of Stomatology The First Medical CenterChinese PLA General HospitalBeijing 100853China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Journals Publishing Center University of Science and Technology BeijingBeijing 100083China Department of Medical Imaging Air Force Medical CenterPLABeijing 100142China

3Y-TZP/3wt%Al_(2)O_(3) powder was coated with varying amounts of BN using the urea and borate reaction sintering method,and then multiphase ceramics were prepared by hot pressing *** micro-topography and the compositional analysis of synthesized ceramics were conducted through scanning electron microscopy,transmission electron microscopy and X-ray diffraction.A mechanical tester was used to analyze the Vickers hardness,fracture toughness,and bending strength of the synthesized *** results showed that the ceramic with a BN content of 12wt%showed the best processability,but had diminished mechanical properties(such as fracture toughness and bending strength).The ceramic with a BN content of 9wt%showed better processability than those with 3wt%and 6wt%***,the fracture toughness was affected by the addition of 9wt%BN,making this ceramic only usable as a base material for a three-unit fixed *** contrast,the ceramics with a BN content of 3wt%or 6wt%fulfilled the criteria for use in multi-unit restoration,but their low processability made them unsuitable for milling after sintering.

关键词： multiphase ceramic boron nitride mechanical properties reaction sintering method

θ-Type Derivation and Derivation Superalgebra of the Finite-Dimensional Modular Lie Superalgebra W（m, n, l, t_）

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Journal of Mathematical Research and Exposition 2008年第2期28卷 297-304页

作者： fang Xiao chao ZHANG Yong Zheng Department of Mathematics Harbin College Heilongjiang 150080 China Department of Mathematics Northeast Normal University Jilin 130024 China

In this paper F always denotes a field of characteristic p 〉 2. We construct the finitedimensional modular Lie superalgebra W（m,n, l, t_） over a field F, define θ-type derivation and determine the derivation super... 详细信息

关键词： modular Lie superalgebra generator derivation.

基于稀疏阵列的多带信号频率和到达角联合估计

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航天电子对抗 2024年第4期40卷 20-25,38页

作者：赵雪成李娟慧许华健方超南京电子设备研究所江苏南京210000

随着工作频段的不断拓展,传统的基于空时Nyquist采样的多目标源频率和到达角联合估计方法受到阵列孔径和采样速率的约束,提高估计精度往往伴随着较高的硬件成本。为此,基于互质阵列设计了一种十字型空时欠采样接收结构,并结合噪声空间... 详细信息

随着工作频段的不断拓展,传统的基于空时Nyquist采样的多目标源频率和到达角联合估计方法受到阵列孔径和采样速率的约束,提高估计精度往往伴随着较高的硬件成本。为此,基于互质阵列设计了一种十字型空时欠采样接收结构,并结合噪声空间重构、信源相关性配对,提出了一种具备闭式解的频率和到达角的无模糊估计方法。得益于稀疏阵列可有效拓展阵列孔径,所提方法相比基于传统均匀线阵的方法,在相同的硬件资源和较低信噪比条件下即可取得明显的估计精度提升效果。

关键词：频率和到达角联合估计互质阵列空域欠采样时域欠采样

Parallel algorithm for viewshed analysis on a modern GPU

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International Journal of Digital Earth 2011年第6期4卷 471-486页

作者： fang chao Yang Chongjun Chen Zhuo Yao Xiaojing Guo Hantao State Key Laboratory of Remote Sensing Science Jointly Sponsored by The Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal UniversityBeijingChina Department of 3D product Beijing GeoBeans Information Technology Co.LtdBeijingChina

Spatial analysis,including viewshed analysis,is an important aspect of the Digital Earth *** analysis is usually performed on a large scale,so efficiency is important in any Digital Earth application making these *** this paper,a real-time algorithm for viewshed analysis in 3D scenes is presented by using the parallel computing capabilities of a graphics processing unit(GPU).In contrast to traditional algorithms based on line-of-sight,this algorithm runs completely within the programmable 3D visualization pipeline to render 3D terrains with viewshed *** most important difference is its integration of the viewshed calculation with the rendering *** areas are rendered as shadows in the 3D *** algorithm process is paralleled by rasterizer units in the graphics card and by vertex and pixel shaders executed on the *** have implemented this method in our 3D Digital Earth system with the DirectX 9.0c API and tested on some consumer-level PC platforms with interactive framerates and high image *** algorithm has been widely used in related systems based on Digital Earth.

关键词： viewshed analysis vertex and pixel shader GPU shadow map 3D representation visualization Digital Earth DEM

Constituent phases of the passive film formed on 2205 stainless steel by dynamic electrochemical impedance spectroscopy

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 42-47页

作者： Xue-qun Cheng Cheng-tao Li chao-fang Dong Xiao-gang Li Corrosion and Protection Center University of Science and Technology Beijing Beijing 100083 China Key Laboratory of the Ministry of Education of China for Corrosion and Protection Beijing 100083 China

The passive film formed on 2205 duplex stainless steel（DSS） in 0.5 M NaHCO3＋0.5 M NaCl aqueous solution was characterized by electrochemical measurements,including potentiodynamic anodic polarization and dynamic electrochemical impedance spectroscopy（DEIS）.The results demonstrate that there is a great difference between the passive film evolutions of ferrite and *** impedance values of ferrite are higher than those of *** impedance peaks of ferritic and austenitic phases correspond to the potential of 0.15 and 0.25 V in the low potential range and correspond to 0.8 and 0.75 V in the high potential *** evolutions of the capacitance of both phases are reverse compared to the evolutions of *** thickness variations obtained from capacitance agree well with those of impedance *** results can be used to explain why pitting corrosion occurs more easily in austenite phase than in ferrite phase.

关键词： stainless steel electrochemical impedance spectroscopy ferrite austenite passivation films

“杜苏芮”台风期间厦门港小型船只避风场所选择分析

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中国海事 2024年第4期 48-50页

作者：黄炜徐建军方超柴田厦门港引航站福建厦门361026 集美大学福建厦门361021

针对“杜苏芮”台风期间厦门港内小型船只避风场所选择的实际情况进行调查,分析总结小型船只避风场所选择特点、避风坞使用和管理存在的不足,提出优化船只进出坞流程、对现有避风坞内进行分区停泊管理及建设客船/小型油船专用避风坞等建... 详细信息

针对“杜苏芮”台风期间厦门港内小型船只避风场所选择的实际情况进行调查,分析总结小型船只避风场所选择特点、避风坞使用和管理存在的不足,提出优化船只进出坞流程、对现有避风坞内进行分区停泊管理及建设客船/小型油船专用避风坞等建议,供相关管理部门参考。

关键词： “杜苏芮”台风厦门港小型船只避风场所对策

Failure analysis of AZ31 magnesium alloy sheets based on the extended GTN damage model

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1198-1207页

作者： Rui-ze Wang Zhang-hua Chen Yu-jie Li chao-fang Dong School of Mathematics and Physics University of Science and Technology Beijing Xi’an Research Institute Co. Ltd.China Coal Technology & Engineering Group Crop. School of Material Engineering University of Science and Technology Beijing

Based on the Gurson-Tvergaard-Needleman （GTN） model and Hill＇s quadratic anisotropic yield criterion, a combined experimental-numerical study on fracture initiation in the process of thermal stamping of Mg alloy AZ31 sheets was carried out. The aim is to predict the formability of thermal stamping of the Mg alloy sheets at different temperatures. The presented theoretical framework was implemented into a VUMAT subroutine for ABAQUS/EXPLICIT. Internal damage evolution due to void growth and coalescence developed at different temperatures in the Mg alloy sheets was observed by scanning electron microscopy （SEM）. Moreover, the thermal effects on the void growth, coalescence, and fracture behavior of the Mg alloy sheets were analyzed by the extended GTN model and forming limit diagrams （FLD）. Parameters employed in the GTN model were determined from tensile tests and numerical iterative computation. The distribution of major and minor principal strains in the specimens was determined from the numerical results. Therefore, the corresponding forming limit diagrams at different stress levels and temperatures were drawn. The comparison between the predicted forming limits and the experimental data shows a good agreement.

关键词： magnesium alloys failure analysis microstructure anisotropy stamping