检索结果-南通市图书馆

Detection of Nonlinear Behavior Induced by Hard Limiting in Voltage Source Converters in Wind Farms Based on Higher-order Spectral Analysis

引用

Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 630-645页

作者： Zetian Zheng Shaowei huang Qiangsheng Bu Chen Shen jun Yan State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjingChina

In recent years, sub-synchronous oscillation accidents caused by wind power integration have received extensive attention. The recorded constant-amplitude waveforms can be induced by either linear or nonlinear oscillation mechanisms. Hence, the nonlinear behavior needs to be distinguished prior to choosing the analysis method. Since the 1960s, the higher-order statistics(HOS) theory has become a powerful tool for the detection of nonlinear behavior(DNB) in production quality control wherein it has mainly been applied to mechanical condition monitoring and fault diagnosis. This study focuses on the hard limiters of the voltage source converter(VSC) control systems in the wind farms and attempts to detect the nonlinear behavior caused by bi-or uni-lateral saturation hard limiting using the HOS analysis. First, the conventional describing function is extended to obtain the detailed frequency domain information on the bi-and uni-lateral saturation hard limiting. Furthermore, the bi-and tri-spectra are introduced as the HOS, which are extended into bi-and tri-coherence spectra to eliminate the effects of the linear parts on the harmonic characteristics of hard limiting in the VSC control system, respectively. The effectiveness of the HOS in the DNB and the classification of the hard-limiting types is proven, and its detailed derivation and estimation procedure is presented. Finally, the quadratic and cubic phase coupling in the signals is illustrated, and the performance of the proposed method is evaluated and discussed.

关键词： Bi-coherence spectrum detection of nonlinear behavior hard limiting higher-order statistics tri-coherence spectrum voltage source converter wind farms.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A progressive framework for rotary motion deblurring

引用

Defence Technology（防务技术） 2024年第2期32卷 159-172页

作者： Jinhui Qin Yong Ma jun huang Fan Fan You Du School of Electronic Information Wuhan UniversityWuhan430072China

The rotary motion deblurring is an inevitable procedure when the imaging seeker is mounted in the rotating *** rotary motion deblurring methods suffer from ringing artifacts and noise,especially for large blur *** solve the above problems,we propose a progressive rotary motion deblurring framework consisting of a coarse deblurring stage and a refinement *** the first stage,we design an adaptive blur extents factor(BE factor)to balance noise suppression and details *** a novel deconvolution model is proposed based on BE *** the second stage,a triplescale deformable module CNN(TDM-CNN)is designed to reduce the ringing artifacts,which can exploit the 2D information of an image and adaptively adjust spatial sampling *** establish a standard evaluation benchmark,a real-world rotary motion blur dataset is proposed and released,which includes rotary blurred images and corresponding ground truth images with different blur *** results demonstrate that the proposed method outperforms the state-of-the-art models on synthetic and real-world rotary motion blur *** code and dataset are available at https://***/JinhuiQin/RotaryDeblurring.

关键词： Rotary motion deblurring Progressive framework Blur extents factor TDM-CNN

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structure regulating of metal clusters in carbonized metallic organic frameworks for high-efficient microwave absorption via tuning interaction strength between metals and ligands

引用

Nano Research 2024年第3期17卷 1699-1709页

作者： Chang Sun Kun-Yan Zhao ming-Lu huang Cheng-Long Luo Xu-Dong Chen ming Wang School of Chemistry and Chemical Engineering Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function ManufacturingSouthwest UniversityChongqing 400715China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Carbonized metallic organic frameworks(CMOF)have been attracting attention in microwave absorption(MA)research area because of their diverse structures,tunable compositions,and rich ***,structure regulation on metal clusters in CMOF is achieved by tuning the interaction strength between metals and ligands to enhance microwave absorption *** to relatively weak interaction among copper cations and ligands,copper nanoclusters(CuNC)can be uniformly formed and embedded within the cobalt/zinc(Co/Zn)***,copper cations are added to the Co/Zn bimetallic zeolitic imidazolate frameworks(ZIFs).Secondly,the CMOF composite particles with CuNCs(CuNCs/CoZn-CMOF)were developed by a pyrolysis *** CuNCs/CoZn-CMOF with an appropriate amount of CuNCs can harmonize both dielectric and magnetic *** a result,the minimum reflection loss(RLmin)reaches–45.1 dB at a matching thickness of 2.30 mm and the effective absorption bandwidth(EAB)is 8.80 GHz at a thickness of 3.10 *** broadband response to electromagnetic waves is attributed to interfacial polarization at CuNCs surface and heterogeneous interfaces,impedance matching and multiple scattering of electromagnetic *** study provides a feasible method to develop CMOF microwave absorption materials with high EAB values.

关键词： heterogeneous interface carbonized metallic organic frameworks microwave absorption interfacial polarization

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Sensing Matrix Optimization for Random Stepped-Frequency Signal Based on Two-Dimensional Ambiguity Function

引用

Chinese Journal of Electronics 2024年第1期33卷 161-174页

作者： mingjiu LYU Hao CHEN jun YANG Xia WU ming ZHOU Xiaoyan MA Radar NCO School Air Force Early Warning Academy Department of Early Warning Technology Air Force Early Warning Academy

Compressive sensing technique has been widely applied to achieve range-Doppler reconstruction of high frequency radar by utilizing sparse random stepped-frequency(SRSF) signal, which can suppress the complex electromagnetic interference and greatly reduce the coherent processing interval. An important way to improve the performance of sparse signal reconstruction is to optimize the sensing matrix(SM). However, the existing research on the SM optimization needs to design a measurement matrix with superior performance, which needs a large amount of computation and does not consider the influence of the waveform parameters design. In order to improve the superior reconstruction performance, a novel SM optimization approach for SRSF signal is proposed by using two-dimensional ambiguity function(TDAF) in this paper. Firstly, based on the two-dimensional sparse reconstruction model of the SRSFs, the internal relationship between the waveform parameters and the SM was derived. Secondly, the SM optimization problem was directly transformed into the waveform design of SRSFs. Furthermore, on the basis of analyzing the relationship between the mutual coherence matrix of SM and the TDAF matrix of SRSFs, the purpose of optimizing the SM can be achieved by designing the TDAF of the SRSFs. Based on this analysis, a sparse waveform optimization method with joint constraints of maximum and mean sidelobes of the TDAF by using the genetic algorithm was derived. Compared with the traditional SM optimization method, our method not only avoids generating a new measurement matrix, but also further reduces the complexity of the waveform optimization. Simulation experiments verified the effectiveness of the proposed method.

关键词： Correlation Computational modeling Electromagnetic interference Optimization methods Signal reconstruction High frequency radar Sensors

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Anomalous response to creep deformation from dislocation density during electrically assisted creep aging

引用

Rare Metals 2024年第10期43卷 5268-5283页

作者： Chang Zhou Li-Hua Zhan Chun-Hui Liu ming-Hui huang College of Mechanical and Electrical Engineering Central South University Light Alloys Research Institute State Key Laboratory of Precision Manufacturing for Extreme Service PerformanceCentral South University

Adding numerous dislocations into metallic materials before the forming stage significantly enhances their deformability. However, this beneficial effect of dislocation defects may not have a simple monotonic relationship with increased dislocation density during electroplastic deformation. This is due to the complex interactions among the drifting electrons, dislocations and solute atoms. This study explores the effect of diverse initial dislocation densities on creep deformation during electrically aided creep aging of an aluminum–lithium alloy. Surprisingly, we discovered a threshold value for the dislocation density that affects electroplastic creep, i.e., an enhanced effect from dislocations weakens when exceeding this density threshold(an anomalous response to creep). Microstructural data also reveal that such an anomalous response originates mainly from differences in various dislocation density-tailored configurations, which can influence the dislocation motions and precipitation kinetics of the strengthening T1precipitates under the same action of pulsed currents. This study provides important insights into the dislocation density-mediated electroplastic creep of an aluminum–lithium alloy.

关键词： Al–Cu–Li alloy Creep aging Dislocation density Pulsed currents

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Indium-based electrocatalysts for CO_(2) reduction to C1 products

引用

Chinese Chemical Letters 2024年第6期35卷 134-145页

作者： Qin Cheng ming huang Qingqing Ye Bangwei Deng Fan Dong Research Center for Carbon-Neutral Environmental&Energy Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region Institute(Huzhou)&Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaHuzhou 313000China Suzhou Industrial Technology Research Institute of Zhejiang University Suzhou 215163China

Electrocatalytic CO_(2) reduction at mild conditions is a promising strategy to transform greenhouse gases into fuels or value-added chemicals to solve the increasingly serious environmental and energy *** most crucial factor in determining the CO_(2) reduction performance is to develop efficient electrocatalysts with high selectivity and *** the various electrocatalysts,indium-based catalysts have attracted extensive attention due to their non-toxicity,low cost,and high formic acid/formate *** this work,we comprehensively review the recent development and research progress of indium-based electrocatalysts for CO_(2)*** reaction mechanism,reaction pathways,structure-activity relationship,and strategies to enhance the activity of CO_(2)RR on indium-based catalysts have also been briefly presented and ***,the existing challenges and future developments for indium-based highperformance catalysts for CO_(2)RR are proposed.

关键词： Electrocatalytic CO_(2) reduction In-based catalysts Formate Reaction mechanism Structure-activity relationship

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of drying-wetting cycles on pore characteristics and mechanical properties of enzyme-induced carbonate precipitation-reinforced sea sand

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 291-302页

作者： ming huang Kai Xu Zijian Liu Chaoshui Xu mingjuan Cui College of Civil Engineering Fuzhou UniversityFuzhou350108China Xiamen Rail Transit Construction and Development Group Co. Ltd.Xiamen361000China School of Civil Environment and Mining EngineeringThe University of AdelaideAdelaide5005Australia

Enzyme-induced carbonate precipitation(EICP)is an emanating,eco-friendly and potentially sound technique that has presented promise in various geotechnical ***,the durability and microscopic characteristics of EICP-treated specimens against the impact of drying-wetting(D-W)cycles is under-explored *** study investigates the evolution of mechanical behavior and pore charac-teristics of EICP-treated sea sand subjected to D-W *** uniaxial compressive strength(UCS)tests,synchrotron radiation micro-computed tomography(micro-CT),and three-dimensional(3D)recon-struction of CT images were performed to study the multiscale evolution characteristics of EICP-reinforced sea sand under the effect of D-W *** potential correlations between microstructure characteristics and macro-mechanical property deterioration were investigated using gray relational analysis(GRA).Results showed that the UCS of EICP-treated specimens decreases by 63.7% after 15 D-W *** proportion of mesopores gradually decreases whereas the proportion of macropores in-creases due to the exfoliated calcium carbonate with increasing number of D-W *** micro-structure in EICP-reinforced sea sand was gradually disintegrated,resulting in increasing pore size and development of pore shape from ellipsoidal to columnar and *** gray relational degree suggested that the weight loss rate and UCS deterioration were attributed to the development of branched pores with a size of 100-1000 m m under the action of D-W ***,the results in this study provide a useful guidancee for the long-term stability and evolution characteristics of EICP-reinforced sea sand under D-W weathering conditions.

关键词： Enzyme-induced carbonate precipitation(EICP) Plant-based urease Drying-wetting(D-W)cycles Microstructure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

“Co-coordination force”assisted rigid-flexible coupling crystalline polymer for high-performance aqueous zinc-organic batteries

引用

Chinese Chemical Letters 2024年第9期35卷 501-506页

作者： jun Guo Zhenbang Zhuang Wanqiang Liu Gang huang School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Key Laboratory of Automobile Materials Ministry of EducationDepartment of Materials Science and EngineeringJilin UniversityChangchun 130022China

Organic electrode materials(OEMs)have attracted substantial attention for aqueous zinc-ion batteries(AZIBs)due to their advantages in relieving resource and environmental ***,the potential of OEMs is plagued by their low achievable capacity and high ***,we have proposed a new concept of“co-coordination force”and designed a rigid-flexible coupling crystalline polymer that can overcome the abovementioned *** obtained crystalline polymer(BQSPNs)with multiredox centres makes the BQSPNs exist intermolecular hydrogen bonds(HB)among-C=O,-C=N,and-NH and consequently exhibits transverse two-dimensional arrays and longitudinalπ-πstacking ***,in-situ FTIR,Raman,variable temperature FTIR spectra,and 2D nuclear overhauser effect spectroscopy(NOESY)well capture the existence and evolution process of HB during the electrochemistry reaction process of BQSPNs,uncovering the effect of HB in stabilizing the structure and promoting the reaction *** a result,the BQSPNs with rationally designed“co-coordination force”deliver a high capacity of 459.6 m Ah/g and a stable cycling lifetime for more than 100,000 cycles at 10 A/g in *** results disclose the HB effect and provide a brand-new strategy for high-performance OEMs design.

关键词： Co-coordination force Crystalline polymer Hydrogen bonds Organic electrode materials Aqueous zinc-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Patterns and drivers of seasonal water sources for artificial sand-fixing plants in the northeastern Mu Us sandy land,Northwest China

引用

Pedosphere 2024年第1期34卷 63-77页

作者： Yanwu PEI Laiming huang ming'an SHAO Jiao WANG Yinglong ZHANG Yellow River Delta Modern Agricultural Engineering Laboratory Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Natural Resources and Environment Northwest Agriculture and Forestry UniversityYangling 712100China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences of Chinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Shenmu Ecological Association Shenmu 719399China

Understanding plant water-use patterns is important for improving water-use efficiency and for sustainable vegetation restoration in arid and semi-arid regions. However, seasonal variations in water sources and their control by different sand-fixing plants in water-limited desert ecosystems remain poorly understood. In this study, stable isotopic ratios of hydrogen(δ^(2)H) and oxygen(δ^(18)O) in precipitation, soil water, groundwater, and xylem water were determined to document seasonal changes in water uptake by three representative plant species(Pinus sylvestris var. mongolica Litv., Amygdalus pedunculata Pall., and Salix psammophila) in the northeastern Mu Us sandy land, Northwest China. Based on the depth distribution and temporal variation of measured gravimetric soil water content(SWC), the soil water profile of the three species stands was divided into active(0.01 g g^(-1)45%) layers. Annually, P. sylvestris, A. pedunculata, and S. psammophila obtained most water from deep(59.2%±9.7%, moist layer and groundwater),intermediate(57.4%±9.8%, stable and moist layers), and shallow(54.4%±10.5%, active and stable layers) sources, respectively. Seasonally, the three plant species absorbed more than 60% of their total water uptake from the moist layer and groundwater in the early(june) dry season;then, they switched to the active and stable layers in the rainy season(July–September) for water resources(50.1%–62.5%). In the late(October–November) dry season, P. sylvestris(54.5%–66.2%) and A. pedunculata(52.9%–63.6%) mainly used water from stable and moist layers, whereas S. psammophila(52.6%–70.7%) still extracted water predominantly from active and stable layers. Variations in the soil water profile induced by seasonal fluctuations in precipitation and groundwater levels and discrepancies in plant pheno

关键词： desert ecosystem MixSIAR model plant water uptake soil moisture stable isotopes vegetation restoration water-use efficiency

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Small-signal Stability Constrained Optimal Power Flow Considering Eigenvalue Distribution

引用

Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1052-1062页

作者： Zheng huang Kewen Wang Yi Wang Jing Han jun Liang the School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China Cardiff University Cardiff CF243AAU.K.

In the existing small-signal stability constrained op-timal power flow(SSSC-OPF)algorithms,only the rightmost ei-genvalue or eigenvalues that do not satisfy a given threshold,e.g.,damping ratio threshold and real-part threshold of eigen-value,are considered in the small-signal stability *** effect of steady-state,i.e.,operating point,changes on eigen-values is not fully taken into *** this paper,the small-signal stability constraint that can fully reflect the eigenvalue change and system dynamic performance requirement is formed by analyzing the eigenvalue distribution on the complex *** small-signal stability constraint is embedded into the standard optimal power flow model for generation *** simultaneous solution formula of the SSSC-OPF is es-tablished and solved by the quasi-Newton approach,while pen-alty factors corresponding to the eigenvalue constraints are de-termined by the stabilization degree of constrained *** improve the computation speed,a hybrid algorithm for ei-genvalue computation in the optimization process is proposed,which includes variable selection for eigenvalue estimation and strategy selection for eigenvalue *** effectiveness of the proposed algorithm is tested and validated on the New England 10-machine 39-bus system and a modified practical 68-machine 2395-bus system.

关键词： Damping ratio eigenvalue optimal power flow quasi-Newton approach sensitivity small-signal stability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：