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Exploiting demand-side heterogeneous flexible resources in risk management of power system frequency

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Science China(Technological Sciences) 2024年第5期67卷 1612-1627页

作者： YAO Yu SONG YongHua YE ChengJin DING Yi ZHAO YuMing College of Electrical Engineering Zhejiang UniversityHangzhou310027China state Key Laboratory of Internet of Things for Smart City University of MacaoMacao SAR519000China Shenzhen Power Supply bureau Co. Ltd.Shenzhen518051China

More demand-side flexible resources(DFRs)are participating in the frequency regulation of renewable power systems,whose heterogeneous characteristics have a significant impact on the system frequency ***,selecting suitable DFRs poses a formidable challenge for independent system operators(ISO).In this paper,a reserve allocation methodology for heterogeneous DFRs is proposed to manage the risk of power system ***,a performance curve is developed to describe the cost,capacity,and response speed of ***,a clustering method for multiple distributed DFRs is conducted to calculate the aggregated performance curves and uncertainty ***,the frequency security criterion considering DFRs’performance is constructed,whose linearity makes it can be easily coupled into the system scheduling model and ***,a risk management model for DFRs considering frequency-chance-constraint is proposed to make a trade-off between cost and frequency ***,the model is transformed into mixed integer second-order cone programming(MISOCP)and solved by the commercial *** proposed model is validated by the IEEE 30 and IEEE 118 bus systems.

关键词： demand-side heterogenous flexible resources risk management of power system frequency performance curve aggregation method mixed integer second-order cone programming

Modularized and Parametric Modeling Technology for Finite Element Simulations of Underground Engineering under Complicated Geological Conditions

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 621-645页

作者： Jiaqi Wu Li Zhuo Jianliang Pei Yao Li Hongqiang Xie Jiaming Wu Huaizhong Liu state Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Research Institute of Testing and Inspection Sinohydro Bureau 7 Co.Ltd.Chengdu610213China

The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical *** improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python *** basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web *** modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling *** main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric *** particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling *** and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower *** complicatedmodel is rapidly generated for the simulation,and the simulation results are ***,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.

关键词： Underground engineering modularized and parametric modeling finite element method complex geological structure cloud modeling

Incorporation of source contributions to improve the accuracy of soil heavy metal mapping using small sample sizes at a county scale

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Pedosphere 2024年第1期34卷 170-180页

作者： Jie SONG Xin WANG Dongsheng YU Jiangang LI Yanhe ZHAO Siwei WANG Lixia MA state Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Chinese Academy of Sciences University Beijing 100049China Agricultural and Rural bureau of Luanping County Luanping 068250China

Estimating heavy metal(HM) distribution with high precision is the key to effectively preventing Chinese medicinal plants from being polluted by the native soil. A total of 44 surface soil samples were gathered to detect the concentrations of eight HMs(As, Hg, Cu, Cr, Ni, Zn, Pb, and Cd) in the herb growing area of Luanping County, northeastern Hebei Province, China. An absolute principal component score-multiple linear regression(APCS-MLR) model was used to quantify pollution source contributions to soil HMs. Furthermore, the source contribution rates and environmental data of each sampling point were simultaneously incorporated into a stepwise linear regression model to identify the crucial indicators for predicting soil HM spatial distributions. Results showed that 88% of Cu, 72% of Cr, and 72% of Ni came from natural sources;50% of Zn, 49% of Pb, and 59% of Cd were mainly caused by agricultural activities;and 44% of As and 56% of Hg originated from industrial activities. When three-type(natural, agricultural, and industrial) source contribution rates and environmental data were simultaneously incorporated into the stepwise linear regression model, the fitting accuracy was significantly improved and the model could explain 31%–86% of the total variance in soil HM concentrations. This study introduced three-type source contributions of each sampling point based on APCS-MLR analysis as new covariates to improve soil HM estimation precision, thus providing a new approach for predicting the spatial distribution of HMs using small sample sizes at the county scale.

关键词： absolute principal component score-multiple linear regression Chinese herbal medicine influencing factors spatial distribution stepwise multiple regression

Mapping soil organic matter in cultivated land based on multi-year composite images on monthly time scales

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Journal of Integrative Agriculture 2024年第4期23卷 1393-1408页

作者： Jie Song Dongsheng Yu Siwei Wang Yanhe Zhao Xin Wang Lixia Ma Jiangang Li state Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Agricultural and Rural bureau of Luanping County Luanping 068250China Chinese Academy of Sciences University Beijing 100049China

Rapid and accurate acquisition of soil organic matter(SOM)information in cultivated land is important for sustainable agricultural development and carbon balance *** study proposed a novel approach to predict SOM with high accuracy using multiyear synthetic remote sensing variables on a monthly *** obtained 12 monthly synthetic Sentinel-2 images covering the study area from 2016 to 2021 through the Google Earth Engine(GEE)platform,and reflectance bands and vegetation indices were extracted from these composite *** the random forest(RF),support vector machine(SVM)and gradient boosting regression tree(GBRT)models were tested to investigate the difference in SOM prediction accuracy under different combinations of monthly synthetic *** showed that firstly,all monthly synthetic spectral bands of Sentinel-2 showed a significant correlation with SOM(P<0.05)for the months of January,March,April,October,and ***,in terms of single-monthly composite variables,the prediction accuracy was relatively poor,with the highest R^(2)value of 0.36 being observed in *** monthly synthetic environmental variables were grouped in accordance with the four quarters of the year,the first quarter and the fourth quarter showed good performance,and any combination of three quarters was similar in estimation *** overall best performance was observed when all monthly synthetic variables were incorporated into the ***,among the three models compared,the RF model was consistently more accurate than the SVM and GBRT models,achieving an R^(2)value of *** for band 12 in December,the importance of the remaining bands did not exhibit significant *** research offers a new attempt to map SOM with high accuracy and fine spatial resolution based on monthly synthetic Sentinel-2 images.

关键词： soil organic matter Sentinel-2 monthly synthetic images machine learning model spatial prediction

Effect of relative humidity on the desulfurization performance of calcium-based desulfurizer

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Journal of Environmental Sciences 2024年第4期138卷 179-188页

作者： Juan Lǖ Yu Fu Haiyan Yu HuanWang Zhe Wang Haiyan Chen School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China Guangyuan Emergency Management bureau Guangyuan 628000China

Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance *** this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative *** results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional ***,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration *** contact with the nascent surface maximizes the formation of slaked *** experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative *** with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional *** work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.

关键词： Dry desulfurization Relative humidity Desulfurization efficiency High-efficiency desulfurizer Quicklime digestion

Metallogenesis of the Baidi Au-Sb deposit, southwest Guizhou Province, China: mineralogical and geochemical evidence from sulfur-bearing minerals

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Acta Geochimica 2024年第2期43卷 199-213页

作者： Jun Yan Yong Xia Qinping Tan Zhuojun Xie Guosong Ji state KeyLaboratory of Ore Deposit Geochemistry Institute of GeochemistryChineseAcademy of SciencesGuiyang 550081China Guizhou InstituteofTechnology Guiyang550003China No.102 GeologicalTeam Guizhou Bureau of Geologyand Mineral Exploration&DevelopmentZunyi563003China

The Baidi Au-Sb deposit, which contains 8 t of Au and 10,979 Mt of Sb, is a typical and rare paragenetic deposit located in southwestern Guizhou Province, *** studies have focused on individual ores, but have not combined them to identify their paragenetic mechanism or metallogenic regularity. Therefore, we used field investigations, microscopic observations, and in situ analyses to identify the spatial distribution, mineral paragenesis, compositional evolution, and metallogenic material sources of the ore bodies. We also determined the Au and Sb paragenetic characteristics and the metallogenesis of the deposit. The main Au-bearing minerals in the deposit were early(Apy1–2) and late(Apy3) stage arsenopyrites, as well as pre-mineralization(Py1), mineralization(Py2–5), and late mineralization(Py6–7) stage pyrites. The main Sb-bearing minerals were stibnite(Snt), skinnerite, bournonite,and valentinite. The minerals formed in the order of Py1,Py2–3 + Apy1, Py4–5 + Apy2, Snt, and Py6–7 + *** δ34S values of the arsenopyrites and pyrites ranged from-5 to 5‰, while those of stibnite were mostly less than-5‰ in the later mineralization stages. Sulfur was provided by deep magmatic hydrothermal fluids, but sedimentary sulfur was added in the later stages. Moreover,the trace elemental contents fluctuated and eventually became similar to those of the sedimentary strata. By comprehensively considering the ores along with the geological characteristics of the deposit, we determined that deep magma provided the Au during ore formation. Later tectonic changes provided Sb from the sedimentary strata,which precipitated along fault expansion areas and produced Au and Sb paragenesis.

关键词： Au-Sb mineralization Arsenopyrite Pyrite Stibnite Metallogenetic process

Evaluating CMIP6 models in simulating the North Pacific decadal variability in sea surface salinity

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Science China Earth Sciences 2024年第8期67卷 2661-2680页

作者： Jian CHEN Hailong LIU Pengfei LIN Wenrong BAI Chengzu BAI Lu WANG Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China state Key Laboratory of Geo-Information Engineering Xi’an 710054China Beijing Municipal Climate Center Beijing Meteorological BureauBeijing 100089China Space System Department Equipment Department Beijing 100096China

The North Pacific sea surface salinity(SSS)decadal variability(NPSDV)and its potential forcing were evaluated from 25 coupled models of the Coupled Model Intercomparison Project phase 6(CMIP6)considering the prospects for decadal climate *** results indicated that the CMIP6 models generally reproduced the spatial patterns of *** large standard deviation of the SSS anomaly over the strong current regions,such as the Kuroshio-Oyashio Extension(KOE),North Pacific Current(NPC),California Current System(CCS),and Alaskan Coastal Current(ACC),is reflected in the two leading modes of NPSDV:a dipole with out-of-phase loadings in the KOE-NPC versus CCS-ACC and a monopole with positive loading over the *** order of modes is sensitive to individual models that exhibit discrepancies,especially in temporal phases and power *** autoregressive model of order-1 was used to reconstruct the NPSDV with several forcing *** generally weaker influence of forcings in an autoregressive model of order-1 is partly related to the overestimated response time of NPSDV relative to *** NPSDV variances originate from the persistence of SSS anomalies,but the dominant forcing factors are diverse among *** model diversity for the NPSDV simulation mainly arises from the influence of the tropical El Ni?o-Southern Oscillation through teleconnection on the North Pacific Oscillation or Aleutian Low with timescale ***,models that can reproduce the NPSDV well are not dependent on those with larger impacts from the North Pacific oceanic processes.

关键词： North Pacific Sea surface salinity Decadal variability CMIP6 Leading mode

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A Compact UHF Antenna Based on Hilbert Fractal Elements and a Serpentine Arrangement for Detecting Partial Discharg

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Energy Engineering 2024年第5期121卷 1127-1141页

作者： Xiang Lin Jian Fang Ming Zhang Kuang Yin Yan Tian Yingfei Guo Qianggang Wang Guangzhou Power Supply bureau of Guangdong Power Grid Co. Ltd.China Southern Power GridGuangzhou510620China state Key Laboratory of Power Transmission Equipment Technology School of Electrical EngineeringChongqing UniversityChongqing400044China

Efforts to protect electric power systems from faults have commonly relied on the use of ultra-high frequency(UHF)antennas for detecting partial discharge(PD)as a common precursor to ***,the effectiveness of existing UHF antennas suffers from a number of challenges such as limited bandwidth,relatively large physical size,and low detection *** present study addresses these issues by proposing a compact microstrip patch antenna with fixed dimensions of 100 mm×100 mm×1.6 *** results of computations yield an optimized antenna design consisting of 2nd-order Hilbert fractal units positioned within a four-layer serpentine arrangement with a fractal unit connection distance of 3.0 ***,the optimized antenna design achieves a detection bandwidth for which the voltage standing wave ratio is less than 2 that is approximately 97.3%of the UHF frequency range(0.3–3 GHz).Finally,a prototype antenna is fabricated using standard printed circuit board technology,and the results of experiments demonstrate that the proposed antenna is capable of detecting PD signals at a distance of 8 m from the discharge source.

关键词： Power system fault partial discharge UHF antenna fractal antenna micro-strip antenna

Unveiling the impact and mechanism of digital technology on agricultural economic resilience

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Chinese Journal of Population,Resources and Environment 2024年第2期22卷 136-145页

作者： Tianshu Quan Hui Zhang Tianli Quan Yi Yu College of Economics and Management Nanjing Forestry UniversityNanjing 210037China state Administration of Taxation Huai’an Taxation bureau Huai’an 223300China College of Economics and Management Nanjing Agricultural UniversityNanjing 210095China

Enhancing the economic resilience of agriculture is essential for promoting sustainable and high-quality agricultural *** emergence of digital technology has created new opportunities in this ***,existing research predominantly focuses on traditional agricultural factors and ***,the impact of digital technology on agricultural economic resilience within the broader context of the“production-operation-industry”system in agriculture has not been comprehensively *** bridge this gap,this study analyzes panel data from 30 Chinese provinces from 2011 to *** employs the static Van Dorn’s law and a dynamic spatial panel model to examine how digital technology empowers agricultural *** findings indicate a continuous strengthening of digital technology development in China,albeit with significant polarization and spatial ***,the resilience of the agricultural economy undergoes notable fluctuations,initially narrowing and subsequently displaying an upward *** technology clearly plays a pivotal role in empowering resilience through agricultural scale operation,industrial transformation,and technological *** impact,particularly on the promotion of resilience in the eastern region and non-grain-producing areas and on high-level agricultural economies,also shows regional and technological variations.

关键词： Digital technology Agricultural economic resilience Counterfactual method Dynamic spatial panel model Agricultural scale