检索结果-南通市图书馆

Fusion of Ground-Based and Spaceborne Radar Precipitation Based on Spatial Domain Regularization

Journal of Meteorological Research 2024年第2期38卷 285-302页

作者： Anfan HUANG Leilei KOU Yanzhi LIANG Ying MAO Haiyang GAO Zhigang CHU School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Collaborative innovation center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044

High-quality and accurate precipitation estimations can be obtained by integrating precipitation information measures using ground-based and spaceborne radars in the same target *** the true precipitation state is a typical inverse problem for a given set of noisy radar precipitation *** regularization method can appropriately constrain the inverse problem to obtain a unique and stable *** different types of precipitation with different prior distributions,the L_(1) and L_(2) norms were more effective in constraining stratiform and convective precipitation,*** a combination of L_(1) and L_(2) norms,the Huber norm is more suitable for mixed precipitation *** study uses different regularization norms to combine precipitation data from the C-band dual-polarization ground radar(CDP)and dual-frequency precipitation radar(DPR)on the Global Precipitation Measurement(GPM)mission core *** to single-source radar data,the fused figures contain more information and present a comprehensive precipitation structure encompassing the reflectivity and precipitation *** 27 precipitation cases,the fusion results utilizing the Huber norm achieved a structural similarity index measure(SSIM)and a peak signal-to-noise ratio(PSNR)of 0.8378 and 30.9322,respectively,compared with the CDP *** fusion results showed that the Huber norm effectively amalgamate the features of convective and stratiform precipitation,with a reduction in the mean absolute error(MAE;16.1%and 22.6%,respectively)and root-mean-square error(RMSE;11.7%and 13.6%,respectively)compared to the 1-norm and ***,in contrast to the fusion results of scale recursive estimation(SRE),the Huber norm exhibits superior capability in capturing the localized precipitation intensity and reconstructing the detailed features of precipitation.

关键词： dual-frequency precipitation radar(DPR) dual-polarization radar data fusion regularization Huber norm

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

SAC-Based Computation Offloading for Reconfigurable Intelligent Surface-Aided Mobile Edge Networks

引用

China Communications 2024年第6期21卷 261-270页

作者： Li Bin Qian Zhen Fei Zesong School of Computer science Nanjing University of Information Science&TechnologyNanjing 210044China Jiangsu Collaborative innovation center of Atmospheric Environment and Equipment technology(CICAEET) Nanjing University of Information Science&TechnologyNanjing 210044 School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

In this paper,we concentrate on a reconfigurable intelligent surface(RIS)-aided mobile edge computing(MEC)system to improve the offload efficiency with moving user equipments(UEs).We aim to minimize the energy consumption of all UEs by jointly optimizing the discrete phase shift of RIS,UEs’transmitting power,computing resources allocation,and the UEs’task offloading strategies for local computing and *** formulated problem is a sequential decision making across multiple coherent time ***,the mobility of UEs brings uncertainties into the decision-making *** cope with this challenging problem,the deep reinforcement learning-based Soft Actor-Critic(SAC)algorithm is first proposed to effectively optimize the discrete phase of RIS and the UEs’task offloading ***,the transmitting power and computing resource allocation can be determined based on the *** results demonstrate that the proposed algorithm can be trained more stably and perform approximately 14%lower than the deep deterministic policy gradient benchmark in terms of energy consumption.

关键词： MEC RIS soft actor-critic user mobility

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

Differences in Variations of Long-Lived and Short-Lived Summer Heat Waves during 1981-2020 over Eastern China and Their Corresponding Large-Scale Circulation Anomalies

引用

Journal of Meteorological Research 2024年第3期38卷 414-436页

作者： Liqun JI Haishan CHEN Collaborative innovation center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University of Information Science&TechnologyNanjing210044China School of Atmospheric sciences Nanjing University of Information Science&TechnologyNanjing210044China

Using daily maximum temperature(Tmax)data from 516 observation stations in eastern China from 1981 to 2020,this study employed a relative threshold method to define short-and long-lived heat waves(HWs)by considering regional climate differences to investigate the spatial characteristics and evolution of large-scale circulation during summer *** results demonstrated spatial disparities in the frequency distribution of HWs of different durations and differences in the magnitude of duration and intensity between short-and long-lived *** orthogonal function analysis revealed three dominant spatial modes for both short-and long-lived *** first mode showed that short-lived HWs occur prominently in both northern and southern regions,whereas long-lived HWs mainly occur in the northern *** second mode was characterized by a meridional dipole pattern in both *** third mode exhibited a quadrupole pattern for short-lived HWs and a tripole pattern for long-lived *** in the center locations of anomalies in the 500-hPa geopotential height and 850-hPa wind fields significantly influenced the temperature and precipitation anomaly distribution of typical HWs by affecting the warm column in the lower troposphere,cloud distribution,and moisture ***,the atmospheric circulation evolution processes of typical HWs associated with the different modes of long-and short-lived HWs were linked to distinct teleconnection *** the three modes of long-lived(short-lived)HWs,there was stronger(weaker)wave flux activity with multiple(single)propagation *** westward Atlantic wave train activity at 300 hPa triggered the synergistic action of meridional and zonal wave fluxes,favoring the strengthening and maintenance of positive anomalies in geopotential height of 500 *** may have contributed to the formation of long-lived *** findings provide valuable insights to enhance our understanding and prediction of summer

关键词： short-lived heat waves(HWs) long-lived HWs empirical orthogonal function(EOF)modes large-scale atmospheric circulation

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

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

引用

Nano Research 2024年第1期17卷 5-17页

作者： Tian Wang Yating Wang Yuhang Li Chunzhong Li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of Chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(CH_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of CH_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-CH_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

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

Interdecadal Variations of ENSO Impacts over the Indo-Northwest Pacific Region and the Related Mechanisms

引用

Journal of Meteorological Research 2024年第2期38卷 235-248页

作者： Hongxia LAN Jing MA Haiming XU Jingjia LUO Collaborative innovation center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(KLME/ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric sciences Nanjing University of Information Science&TechnologyNanjing 210044

Owing to limited observations,it remains unknown whether the impact of El Niño-Southern Oscillation(ENSO)on the Indian Ocean-Northwest Pacific(IO-NWP)climate showed decadal changes in the early 20th *** multi-source reanalysis and hindcast datasets from the ECMWF and NOAA extending back to 1901,this study investigates interdecadal variations of the impact of ENSO on the IO-NWP climate from 1901 to *** is found that the influence of ENSO on the IO-NWP climate shows“strong-weak-strong”interdecadal change during *** is characterized by much weaker Indian Ocean sea surface temperature(SST)warming and a weaker NWP subtropical anticyclone(NWPSA)in the following summer of El Ni?o during 1946-1967,compared with those in the other two periods(1901-1945 and 1968-2009).Analyses of the datasets indicate that the interdecadal variation is mainly associated with the change in ENSO *** contrast to the period of 1946-1967,a greater SST variance occurred in the central-eastern equatorial Pacific during 1901-1945 and 1968-2009.A stronger El Ni?o tends to generate more significant anticyclonic anomalies over the southeast Indian Ocean through *** northwesterly anomalies to the south of the anticyclone weaken the southeast trade winds and warm the south Indian Ocean SST via wind-evaporation-SST feedback,and the positive south Indian Ocean SST anomalies trigger westward-propagating oceanic Rossby waves to induce stronger warming of the southwest Indian Ocean,leading to a significant asymmetric wind pattern across the equator in *** profound northeastward winds on the north side weaken the southwest monsoon,leading to a“second warming”over the north Indian Ocean in summer,which anchors the eastward-propagating warm Kelvin waves and results in a stronger NWPSA by inducing surface divergence and suppressing deep convection.

关键词： ENSO Indo-Northwest Pacific Northwest Pacific subtropical anticyclone decadal changes

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

Evaluating quality of motion for unsupervised video object segmentation

引用

Optoelectronics Letters 2024年第6期20卷 379-384页

作者： CHENG Guanjun SONG Huihui Jiangsu Key Laboratory of Big Data Analysis technology Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment TechnologyNanjing University of Information Science&TechnologyNanjing 210044China12

Current mainstream unsupervised video object segmentation(UVOS) approaches typically incorporate optical flow as motion information to locate the primary objects in coherent video frames. However, they fuse appearance and motion information without evaluating the quality of the optical flow. When poor-quality optical flow is used for the interaction with the appearance information, it introduces significant noise and leads to a decline in overall performance. To alleviate this issue, we first employ a quality evaluation module(QEM) to evaluate the optical flow. Then, we select high-quality optical flow as motion cues to fuse with the appearance information, which can prevent poor-quality optical flow from diverting the network's attention. Moreover, we design an appearance-guided fusion module(AGFM) to better integrate appearance and motion information. Extensive experiments on several widely utilized datasets, including DAVIS-16, FBMS-59, and You Tube-Objects, demonstrate that the proposed method outperforms existing methods.

关键词： Evaluating quality of motion for unsupervised video object segmentation

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 Non-Parametric Scheme for Identifying Data Characteristic Based on Curve Similarity Matching

引用

IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1424-1437页

作者： Quanbo Ge Yang Cheng Hong Li Ziyi Ye Yi Zhu Gang Yao School of Automation Nanjing University of Information Science&TechnologyJiangsu Provincial University Key Laboratory of Big Data Analysis and Intelligent SystemsNanjing University of Information Science&Technologyand the Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET)Nanjing University of Information Science&TechnologyNanjing 210044China School of Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China China Classification Society Nantong Office Nantong 226006China Chinese Flight Test Establishment Xi’an 710089China School of Mathematics Tsinghua UniversityBeijing 100084China School of Automation Nanjing University of Information Science&TechnologyNanjing 210044China Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China IEEE

For accurately identifying the distribution charac-teristic of Gaussian-like noises in unmanned aerial vehicle(UAV)state estimation,this paper proposes a non-parametric scheme based on curve similarity *** the framework of the pro-posed scheme,a Parzen window(kernel density estimation,KDE)method on sliding window technology is applied for roughly esti-mating the sample probability density,a precise data probability density function(PDF)model is constructed with the least square method on K-fold cross validation,and the testing result based on evaluation method is obtained based on some data characteristic analyses of curve shape,abruptness and *** com-parison simulations with classical methods and UAV flight exper-iment shows that the proposed scheme has higher recognition accuracy than classical methods for some kinds of Gaussian-like data,which provides better reference for the design of Kalman filter(KF)in complex water environment.

关键词： Curve similarity matching Gaussian-like noise non-parametric scheme parzen window.

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

Polyetherketoneketone/carbon fiber composites with an amorphous interface prepared by solution impregnation

引用

新型炭材料（中英文） 2024年第4期39卷 692-702页

作者： ZHANG Feng LI Bo-lan JIAO Meng-xiao LI Yan-bo WANG Xin YANG Yu YANG Yu-qiu ZHANG Xiao-hua MOE Key Laboratory of Textile science&technology College of TextilesInnovation Center for Textile Science and TechnologyDonghua UniversityShanghai 201620China Key Laboratory of Carbon Materials National Engineering Laboratory for Carbon Fiber TechnologyInstitute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China

Interfacial adhesion between carbon fibers(CF)and polyetherketoneketone(PEKK)is a key factor that affects the mechanical performances of their *** is therefore of great importance to impregnate the CF bundles with PEKK as effi-ciently as *** report that PEKK with a good dispersion in a mixed solution of 4-chlorophenol and 1,2-dichloroethane can be introduced onto CF surfaces by solution impregnation and curing at 280,320,340 and 360℃.The excellent wettability or infiltra-tion of the PEKK solution guarantees a full covering and its tight binding to CFs,making it possible to evaluate the interfacial shear strength(IFSS)with the microdroplet *** interior of the CF bundles is completely and uniformly filled with PEKK by solu-tion impregnation,leading to a high interlaminar shear strength(ILSS).The maximum IFSS and ILSS reached 107.8 and 99.3 MPa,*** superior shear properties are ascribed to the formation of amorphous PEKK in the small spaces between CFs.

关键词： Polyetherketoneketone Carbon fiber Wettability Amorphous adhesion Interfacial strength

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

In-doping collaboratively controlling back interface and bulk defects to achieve efficient flexible CZTSSe solar cells

引用

Journal of Energy Chemistry 2024年第2期89卷 10-17,I0002页

作者： Quanzhen Sun Yifan Li Caixia Zhang Shunli Du Weihao Xie Jionghua Wu Qiao Zheng Hui Deng Shuying Cheng Institute of Micro-Nano Devices and Solar Cells College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108FujianChina Fujian science&technology innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianChina Jiangsu Collaborative innovation center of Photovoltaic science and Engineering Changzhou 213164JiangsuChina

Focusing on the low open circuit voltage(V_(OC))and fill factor(FF)in flexible Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells,indium(In)ions are introduced into the CZTSSe absorbers near Mo foils to modify the back interface and passivate deep level defects in CZTSSe bulk concurrently for improving the performance of flexible *** results show that In doping effectively inhibits the formation of secondary phase(Cu(S,Se)_(2))and *** studies demonstrate that the barrier height at the back interface is decreased and the deep level defects(Cu_(Sn)defects)in CZTSSe bulk are ***,the carrier concentration is increased and the V_(OC) deficit(V_(OC,def))is decreased significantly due to In ***,the flexible CZTSSe solar cell with 10.01%power conversion efficiency(PCE)has been *** synergistic strategy of interface modification and bulk defects passivation through In incorporation provides a new thought for the fabrication of efficient flexible kesterite-based solar cells.

关键词： Flexible solar cells Cu_(2)ZnSn(S,Se)_(4) Back interface Deep level defects Barrier height

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

Impacts of Roof/Ground Mitigation Strategies on Improving the Urban Thermal Environment and Human Comfort over the Yangtze River Delta, China

引用

Journal of Meteorological Research 2024年第1期38卷 108-125页

作者： Hongyun MA Mi ZHANG Haishan CHEN Yan WANG Collaborative innovation center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric sciences Nanjing UniversityNanjing 210023 Experimental Teaching center for Meteorology and Environment Nanjing University of Information Science&TechnologyNanjing 210044

The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the Yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.

关键词： urban heat island human thermal comfort urban canopy mitigation strategies Yangtze River Delta Weather Research and Forecasting Model(WRF) Urban Canopy Model(UCM)

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

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：