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THREE-DIMENSIONAL GRAVITY-MAGNETIC CROSS-GRADIENT JOINT INVERSION BASED ON STRUCTURAL COUPLING AND A FAST GRADIENT METHOD

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Journal of Computational Mathematics 2019年第6期37卷 758-777页

作者： Yuanping Zhang yanfei wang Key Laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

In order to effectively solve the low precision problem of the single gravity density inversion and the magnetic susceptibility inversion,and the limitation of the gravity?magnetic joint inversion method based on the petrophysical parameter constraint,this paper studies the three-dimensional gravity?magnetic cross-gradient joint inversion based on the structural coupling and the fast optimization *** on the forward and inversion modeling of three-dimensional gravity density and three-dimensional magnetic susceptibility using the same underground grid,along with cross-gradient coupling as the structural cons train t,we propose a new gravit y?magnetic joint inversion objective function including the data fitting term,the total variation regularization constraint term and the crossgradient term induced by the structural coupling?The depth weighted constraint and the data weighting constraint are included into the objective function,which requires different physical property models to minimize their respective data *** the same time,the cross-gradient term tends to zero,so that the structure of the gravity and magne ic models tends to be *** realization,we address a fast and efficient gradient algorithm to iteratively solve the objective *** apply this new joint inversion algorithm to the 3D gravity-magnetic model inversion test and compare it with the results of a single inversion *** experimental tests of synthetic data indicate that the gravity-magnetic cross-gradient joint inversion method can effectively improve the accuracy of the anomaly position and numerical accuracy of the inverted anomaly physical parameters compared with the single physical inversion method.

关键词： Joint inversion Gravity Magnet Cross-gradient Regularization

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Structural adaptive and optimal speckle filtering in multilook full polarimetric SAR images

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Journal of Systems Engineering and Electronics 2007年第2期18卷 217-222页

作者： Sun Nan Zhang Bingchen wang yanfei Graduate School Chinese Academy of Sciences Beijing 100039 P. R. China Inst. of Electronics Chinese Academy of Sciences Beijing 100080 P. R. China (Received December 2 2005

A novel approach is proposed for speckle reduction in multilook full polarimetric SAR images. In contrast to others, this approach adopts an enhanced structure detection method to estimate the parameters of the polarimetric covariance matrix for the multilook polarimetric whitening filtering （MPWF） algorithm and thus a structural adaptive and optimal speckle filter is developed. To evaluate the present approach, NASA SIR-C/X- SAR, L band, four-look processed polarimetric SAR data of the Tian-Mountain Forest is used for simulation. Experimental results demonstrate the effectiveness of this novel filtering algorithm in case of both speckle reduction and preservation of texture information. Comparisons with other methods are also made.

关键词： MPWF Geometrical-ratio detectors ESDMPWF Speckle Multilook polarimetric SAR.

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Removal of ammonium and nitrate through Anammox and FeS-driven autotrophic denitrification

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Frontiers of Environmental Science & Engineering 2023年第6期17卷 127-139页

作者： yanfei wang Xiaona Zheng Guangxue Wu Yuntao Guan Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China State Environmental Protection Key Laboratory of Microorganism Application and Risk Control School of EnvironmentTsinghua UniversityBeijing 100084China Civil Engineering School of EngineeringCollege of Science and EngineeringNational University of IrelandGalwayGalway H91 TK33Ireland

An autotrophic denitrifying bioreactor with iron sulfide(FeS)as the electron donor was operated to remove ammonium(NH_(4)^(+))and nitrate(NO_(3)^(-))synergistically from wastewater for more than 298 *** concentration of FeS greatly affected the removal of NH_(4)^(+)/NO_(3)^(-).Additionally,a low hydraulic retention time worsened the removal efficiency of NH_(4)^(+)/NO_(3)^(-).When the hydraulic retention time was 12 h,the optimal removal was achieved with NH_(4)^(+)and NO_(3)^(-)removal percentages both above 88%,and the corresponding nitrogen removal loading rates of NH_(4)^(+)and NO_(3)^(-)were 49.1 and 44.0 mg/(L·d),*** removal of NH_(4)^(+)mainly occurred in the bottom section of the bioreactor through sulfate/ferric reducing anaerobic ammonium oxidation(Sulfammox/Feammox),nitrification,and anaerobic ammonium oxidation(Anammox)by functional microbes such as Nitrospira,Nitrosomonas,and Candidatus ***,NO_(3)^(-)was mainly removed in the middle and upper sections of the bioreactor through autotrophic denitrification by Ferritrophicum,Thiobacillus,Rhodanobacter,and Pseudomonas,which possessed complete denitrification-related genes with high relative abundances.

关键词： Anammox Denitrification FeS NH_(4)^(+)/NO_(3)^(−) Sulfammox

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基于机器学习的不同地幔端元来源玄武岩判别及其元素地球化学特征研究

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岩石学报 2025年第1期41卷 339-350页

作者：崔岩王彦飞孟凡超刘浩毅刘展飞山东科技大学地球科学与工程学院青岛266590 中国科学院地质与地球物理研究所中国科学院油气资源研究重点实验室北京100029 中国科学院大学北京100049 中国科学院地球科学研究院北京100029 中国石油大学(华东)地球科学与技术学院青岛266580

地幔地球化学是固体地球科学研究的重要组成部分,认识和识别地幔不均一性对于探讨地幔内部物质循环、揭示地球演化规律具有重要意义。目前国际上公认的地幔端元划分方案主要依赖于幔源岩浆岩的同位素数据,但在实际应用中具有一定的局限... 详细信息

地幔地球化学是固体地球科学研究的重要组成部分,认识和识别地幔不均一性对于探讨地幔内部物质循环、揭示地球演化规律具有重要意义。目前国际上公认的地幔端元划分方案主要依赖于幔源岩浆岩的同位素数据,但在实际应用中具有一定的局限性。相较于同位素数据,主、微量元素数据的数量更大,实际应用前景更广阔。从数据分析的角度看,幔源岩浆岩的主微量元素有27个指标,远多于常用的Sr、Nd、Pb同位素指标,变量数目的增加可能会提高分类判断的精度,但是也会给分类带来两个问题:一是建模所需的样本数量大大增加;二是传统的二维、三维图版法不再适用。针对上述问题,本文从数据和方法两个层面入手:首先从全球共享地球化学数据库GEOROC和PetDb获取数据;然后采用机器学习方法建立判别模型,最终获得了基于元素特征的玄武岩地幔端元类型逻辑回归模型。该模型不仅具有很好的分类效果,而且有助于分析和总结来自不同地幔端元的玄武岩的元素地球化学特征。该研究对地幔不均一性的精细识别及与其相关的研究工作具有一定的促进作用。

关键词：玄武岩地幔端元划分主、微量元素地球化学数据库机器学习

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Changing Rural Development Inequality in Jilin Province, Northeast China

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Chinese Geographical Science 2013年第5期23卷 620-633页

作者： CHENG Yeqing wang yanfei wang Zheye LUO Xiaolong Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Urban Planning and Design Nanjing University

Rural development inequality is an important practical issue during the course of full establishment of a ′moderately well-off society′ in modern China,and the objective understanding and evaluation of the status and regional inequality of rural development can provide scientific basis for ′building a new countryside′ and coordination development of rural-urban *** on the county-level data of 2000,2005 and 2009,this paper examines the rural development inequality of Jilin Province in Northeast China by establishing a rural development *** spatio-temporal dynamic patterns and domain factors are discussed by using the method of exploratory spatial data analysis and multi-regression *** results are shown as ***,most of the counties were in lower development level,which accounted for 58.3%,62.5% and 66.7% of the total counties in 2000,2005 and 2009,*** characteristics of spatial inequality were very obvious at county *** example,rural development level of Changchun Proper and the proper of seven prefecture-level cities were much higher than that of the surrounding *** counties in the eastern and northern Jilin Province were the lowest regions of rural development level,while the middle counties were the rapid growth areas in rural ***,Moran′s I of rural development index(RDI) was 0.01,–0.16 and –0.06 in 2000,2005 and 2009,respectively,which indicated that spatial agglomeration of RDI was not obvious in Jilin Province,and took on the characteristic of random *** counties of both the units and its adjacent units have higher development level(HH) were transferred from the western areas to the eastern areas,while the countries of both the units and its adjacent units have lower development level(LL) were diffused from the eastern to middle and western Jilin ***,the result of multi-regression analysis showed that the improvement of agricultural production condition,development

关键词： rural development index exploratory spatial data analysis multi-regression model Jilin Province

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基于振动分离特性的荔枝振动器结构优化

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农机化研究 2025年第4期47卷 9-17页

作者：赵紫艳王慰祖王艳飞李君冼昊岚华南农业大学工程学院广州510642

为了研究荔枝振动分离特性,以此为基础优化振动器结构,利用往复振动采收装置在不同振动参数下对荔枝进行振动分离试验,并采用MatLab软件分析高速相机拍摄的荔枝运动视频,获得荔枝运动参数(轨迹、速度、加速度等)。为了确定振动机构的最... 详细信息

为了研究荔枝振动分离特性,以此为基础优化振动器结构,利用往复振动采收装置在不同振动参数下对荔枝进行振动分离试验,并采用MatLab软件分析高速相机拍摄的荔枝运动视频,获得荔枝运动参数(轨迹、速度、加速度等)。为了确定振动机构的最优工作参数,利用Design-Expert软件处理试验数据并得到回归模型,再通过响应曲面分析振动频率、振幅和振动距离对荔枝分离特性(分离时间、碰撞次数和惯性力)的影响,对回归模型进行优化,结果表明:当振动频率为9.7 Hz、振幅为80 mm、振动距离为29.4 mm时,既能保证较短的分离时间又能减轻荔枝果实所受的机械损伤。为了基于最优工作参数对振动器进行结构优化,以采收效率高和损伤小为目标,以尺寸约束、角度约束和强度约束为约束条件,建立多目标优化模型。优化后的振动器为对心曲柄滑块机构,曲柄长度为56 mm,连杆为127 mm,角速度为62 rad/s。经验证,优化后的振动器可以提高采收效率,减少果实所受损伤,为荔枝振动采收器的设计提供依据。

关键词：荔枝振动采收图像处理分离特性结构优化

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Progress on grain growth dynamics in sintering of nano-powders

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Rare Metals 2006年第z1期25卷 471-475页

作者： LIU Chunjing wang Xin JIANG yanfei wang Yongming HAO Shunli School of Material and Engineering Hebei University of Technology Tianjin 300130 China School of Material and Engineering Hebei University of Technology Tianjin 300130 China School of Material and Engineering Hebei University of Technology Tianjin 300130 China School of Material and Engineering Hebei University of Technology Tianjin 300130 China School of Material and Engineering Hebei University of Technology Tianjin 300130 China

Nanostructured materials, characterized by an ultrafine grain size, have stimulated much research interest by virtue of their unusual mechanical, electrical, optical, and magnetic properties. In this paper, the sintering process of nano-powders were reviewed, to which sintering of the traditional materials compared. The microstructural development, i.e., grain growth and densification during sintering as well as the mechanism of crystal surface diffusion and boundary migration were analyzed, and the dynamic models on sintering process were summarized by the relationship of grain growth and pores size, interface diffusion, densification rate, and sintering temperature. Finally, the research tendency of this major on the basis of above models was discussed.

关键词： nano-powders sintering grain boundary grain growth dynamics

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Global evolution of an analyzer angle on the Faraday anomalous dispersion optical filter at 1529 nm

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Chinese Science Bulletin 2013年第36期58卷 4582-4587页

作者： TAO ZhiMing wang yanfei HONG YeLong wang DongYing ZHUANG Wei CHEN JingBiao State Key Laboratory of Advanced Optical Communication System and Network Institute of Quantum Electronics School of ElectronicsEngineering and Computer Science Peking University Department of Physics Bijie University

In order to realize laser frequency stabilization,the global evolution of an analyzer angle on the electrodeless-discharge-vaporlamp-based excited-state Faraday anomalous dispersion optical filter(LESFADOF)with a single transmission peak operating on the Rb1529 nm(5P3/2-4D5/2)is *** find that the transmission of the line center peak at 80°arrives at 14%in a 3 cm length lamp contained natural Rb mixed with 2 torr Xe buffer gas operating at 250°C with 176 MHz radio *** it is used to realize laser frequency stabilization,the LESFADOF at near 80°is *** a single transmission peak or double transmission peaks depend on the rf voltage when two polarizers are crossed.

关键词：法拉第反常色散光学滤波器演进激光稳频无电极放电无线电频率频率稳定激发态

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On the effective inversion by imposing a priori information for retrieval of land surface parameters

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Science China Earth Sciences 2009年第4期52卷 540-549页

作者： wang yanfei MA ShiQian YANG Hua wang JinDi LI XiaoWen Key Laboratory of Petroleum Geophysics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications of Chinese Academy of SciencesBeijing 100875China Department of Industrial Engineering and Operations Research Columbia UniversityNew YorkNY 10027-6902USA

The anisotropy of the land surface can be best described by the bidirectional reflectance distribution function (BRDF). As the field of multiangular remote sensing advances, it is increasingly probable that BRDF models can be inverted to estimate the important biological or climatological parameters of the earth surface such as leaf area index and albedo. The state-of-the-art of BRDF is the use of the linear kernel-driven models, mathematically described as the linear combination of the isotropic kernel, volume scattering kernel and geometric optics kernel. The computational stability is characterized by the algebraic operator spectrum of the kernel-matrix and the observation errors. Therefore, the retrieval of the model coefficients is of great importance for computation of the land surface albedos. We first consider the smoothing solution method of the kernel-driven BRDF models for retrieval of land surface albedos. This is known as an ill-posed inverse problem. The ill-posedness arises from that the linear kernel driven BRDF model is usually underdetermined if there are too few looks or poor directional ranges, or the observations are highly dependent. For example, a single angular observation may lead to an under-determined system whose solution is infinite (the null space of the kernel operator contains nonzero vectors) or no solution (the rank of the coefficient matrix is not equal to the augmented matrix). Therefore, some smoothing or regularization technique should be applied to suppress the ill-posedness. So far, least squares error methods with a priori knowledge, QR decomposition method for inversion of the BRDF model and regularization theories for ill-posed inversion were developed. In this paper, we emphasize on imposing a priori information in different spaces. We first propose a general a priori imposed regularization model problem, and then address two forms of regularization scheme. The first one is a regularized singular value decomposition method

关键词： ill-posed problems land surface parameter retrieval optimization regularization

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Familial Parkinson's Disease-Associated L166P Mutant DJ-1 is Cleaved by Mitochondrial Serine Protease Omi/HtrA2

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Neuroscience Bulletin 2017年第6期33卷 685-694页

作者： Kai Fu yanfei wang Dongkai Guo Guanghui wang Haigang Ren Laboratory of Molecular Neuropathology Jiangsu Key Laboratory of Translational Research and Therapy for Neuropsychiatric Disorders Department of PharmacologyCollege of Pharmaceutical Sciences Soochow University Institute of Precision Medicine Xiangya Hospital Xiangya Medical School Central South University

Parkinson＇s disease（PD） is the most common neurodegenerative movement disorder. Mutations in the DJ-1, including L166 P, are responsible for recessive earlyonset PD. Many lines of evidence have shown that L166 P is not only a loss-of-function mutant, but also a proapoptotic-like protein that results in mitochondrial dysfunction. L166 P has been reported to be unstable and to mislocalize to mitochondria. However, the mechanisms underlying the instability of L166 P compared to wild-type DJ-1 remain largely unknown. Here, we showed that Omi/Htr A2, a mitochondrial serine protease that has also been linked to the pathogenesis of PD, contributed to L166 P instability. Omi directly interacted with and cleaved L166 P in mitochondria to decrease the L166 P level. However,Omi did not bind and cleave wild-type DJ-1. Moreover,Omi cleaved L166 P at both serine residues 3 and 121,while L166 P-induced cell death under H_2O_2 treatment was alleviated by over-expression of Omi. Our data reveal a bridge between DJ-1 and Omi, two PD-associated geneticfactors, which contributes to our understanding of the pathogenesis of PD.

关键词： Parkinson’s disease DJ-1 L166P Instability Omi/HtrA2 Cleavage

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