检索结果-南通市图书馆

Gap Filling of Net Ecosystem CO<sub>2</sub>Exchange (NEE) above Rain-Fed Maize Using Artificial Neural Networks (ANNs)

引用

Journal of Software Engineering and Applications 2021年第5期14卷 150-171页

作者： Babak Safa Timothy J. Arkebauer Qiuming Zhu andy suyker Suat Irmak Daugherty Water for Food Global Institute at the University of Nebraska Lincoln USA Department of Agronomy & Horticulture University of Nebraska-Lincoln Lincoln USA Department of Computer Science University of Nebraska-Omaha Omaha USA School of Natural Resources University of Nebraska-Lincoln Lincoln USA Biological Systems Engineering Department University of Nebraska-Lincoln Lincoln USA

The eddy covariance technique is an accurate and direct tool to measure the Net Ecosystem Exchange (NEE) of carbon dioxide. However, sometimes conditions are not amenable to measurements using this technique. Thus, different methods have been developed to allow gap-filling and quality assessment of eddy covariance data sets. In this study first, two different Artificial Neural Networks (ANNs) approaches, the Multi-layer Perceptron (MLP) trained by the Back-Propagation (BP) algorithm, and the Radial Basis Function (RBF), were used to fill missing NEE data measured above rain-fed maize at the University of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebraska. The gap-filled data were then compared by different statistical indices to gap-filled data obtained with the technique suggested by Suyker and Verma in 2005 [S&V method], and the ANN approach presented by Papale in 2003. The results showed that the RBF network was able to find better fits for missing values compared to the MLP (BP) network and S&V method. In addition, unlike the S&V method, which depends on different gap-filling procedures over the year;the structure of RBF and MLP (BP) networks was constant. However, data analysis indicated Papale’s approach gave better fits than the RBF and MLP (BP) methods. Thus, based on this work, Papale’s approach is the best method to estimate the missing data;though the applied statistical indices, which were used for model evaluation, show little difference between Papale’s approach and the RBF and MLP (BP).

关键词： Gap Filling Net Ecosystem Exchange of Carbon Dioxide Artificial Neural Networks Eddy Covariance System

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

Ultra-large aluminum shape casting:Opportunities and challenges

引用

China Foundry 2024年第5期21卷 397-408页

作者： Qi-gui Wang andy Wang Jason Coryell Advanced Materials Technology&Virtualization GM Global Technical CenterWarrenMI USA

Ultra-large aluminum shape castings have been increasingly used in automotive vehicles,particularly in electric vehicles for light-weighting and vehicle manufacturing cost *** most of them are structural components subject to both quasi-static,dynamic and cyclic loading,the quality and quantifiable performance of the ultra-large aluminum shape castings is critical to their success in both design and *** paper briefly reviews some application examples of ultra-large aluminum castings in automotive industry and outlines their advantages and *** affecting quality,microstructure and mechanical properties of ultra-large aluminum castings are evaluated and discussed as aluminum shape casting processing is very complex and often involves many competing mechanisms,multi-physics phenomena,and potentially large uncertainties that significantly influence the casting quality and *** analysis and mechanical property assessment of an ultra-large aluminum shape casting are *** are highlighted and suggestions are made for robust design and manufacturing of ultra-large aluminum castings.

关键词： ultra-large castings aluminum light-weighting quality microstructure materials properties

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

Water–solid contact electrification and catalysis adjusted by surface functional groups

引用

Nano Research 2024年第4期17卷 3344-3351页

作者： Yusen Su andy Berbille Zhong Lin Wang Wei Tang CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing100049China Georgia Institute of Technology AtlantaGA 30332-0245USA

Chemical functional groups on solid surfaces greatly influence contact electrification(CE)at water–solid *** studies of their effects mainly swapped materials or bonded related molecules to a substrate,introducing other factors of *** work aims at unambiguously demonstrating the role of functional groups in water-polymer *** study the contribution of functional groups,by using ion coupled plasma etching to modify a high-density polyethylene(HDPE)film,a polymer with a naturally quasi-null charge transfer ***(HDPE–F)and hydroxyl(HDPE–OH)functional groups are generated and endowed HDPE with charge withdrawing ***–F withdraws 2.5–2.7 times more charges than HDPE–***,the surface charges accumulated generate electrostatic forces,altering the droplets *** phenomenon provides another approach to study CE,helping to evaluate the contribution of electrons to solid–liquid ***,employing HDPE–F to perform contact-electro-catalysis shows its activity is 2.4 times higher than that of commercial fluorinated films.

关键词： contact-electro-catalysis charge transfer solid–liquid interfaces contact electrification

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

Stability and Generalization of Hypergraph Collaborative Networks

引用

Machine Intelligence Research 2024年第1期21卷 184-196页

作者： Michael K.Ng Hanrui Wu andy Yip Institute of Data Science The University of Hong KongHong KongChina Department of Mathematics The University of Hong KongHong KongChina College of Information Science and Technology Jinan UniversityGuangzhou 510006China

Graph neural networks have been shown to be very effective in utilizing pairwise relationships across ***,there have been several successful proposals to generalize graph neural networks to hypergraph neural networks to exploit more com-plex *** particular,the hypergraph collaborative networks yield superior results compared to other hypergraph neural net-works for various semi-supervised learning *** collaborative network can provide high quality vertex embeddings and hyperedge embeddings together by formulating them as a joint optimization problem and by using their consistency in reconstructing the given *** this paper,we aim to establish the algorithmic stability of the core layer of the collaborative network and provide generaliz--ation *** analysis sheds light on the design of hypergraph filters in collaborative networks,for instance,how the data and hypergraph filters should be scaled to achieve uniform stability of the learning *** experimental results on real-world datasets are presented to illustrate the theory.

关键词： Hypergraphs vertices hyperedges collaborative networks graph convolutional neural networks(CNNs) stability generalization guarantees

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

Determinants of malaria from environmental and poverty aspects in Indonesia:A spatiotemporal perspective,2016-2020

引用

Asian Pacific Journal of Tropical Medicine 2024年第6期17卷 256-267页

作者： Afi Nursafingi Prima Widayani Sidiq Purwoko andy Bhermana Research Center for Public Health and Nutrition Research Organization for HealthNational Research and Innovation AgencyJakartaIndonesia Department of Geographic Information Science Faculty of GeographyUniversitas Gadjah MadaYogyakartaIndonesia Center for Food Crops Research Organization for Agriculture and FoodNational Research and Innovation AgencyJakartaIndonesia

Objective:To investigate the environmental and social aspects of poverty contributing to malaria incidence in Indonesia from 2016 to ***:Random forest regression was used to analyse the independent variables contributing to malaria *** conditions were extracted from remotely sensed data,including vegetation,land temperature,soil moisture,precipitation,and *** contrast,the social aspects of poverty were obtained from government statistical ***:From 2016 to 2020,the contribution of each environmental and social aspect of poverty to malaria incidence fluctuated ***,the top three essential variables were people aged 15 years and above,experiencing poverty(variable importance/VI=32.0%),people experiencing poverty who work in the agricultural sector(VI=14.4%),and precipitation(VI=9.8%).It was followed by people experiencing poverty who are unemployed(VI=9.2%),land temperature(VI=5.2%),people experiencing poverty who have low education(VI=8.0%),soil moisture(VI=7.4%),elevation(VI=6.0%),and vegetation(VI=3.8%).Conclusions:Poverty and variables related to climate have become the crucial determinants of malaria in *** government must strengthen malaria surveillance through climate change mitigation and adaptation programs and accelerate poverty alleviation programs to support malaria elimination.

关键词： Malaria Poverty Climate Random forest Indonesia

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

Gap Filling of Net Ecosystem CO2 Exchange (NEE) above Rain-Fed Maize Using Artificial Neural Networks (ANNs)

引用

Journal of Software Engineering and Applications（软件工程与应用） 2021年第5期

作者： Babak Safa Timothy J.Arkebauer Qiuming Zhu andy suyker Suat Irmak

来源：评论

学校读者我要写书评

暂无评论

引用

Earthquake Science 2024年第6期37卷 514-528页

作者： Feng Huang Xueyang Bao Qili andy Dai Xinfu Li Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055China School of Geophysics and Information Technology China University of Geosciences(Beijing)Beijing 100083China

Existing lithospheric velocity models exhibit similar structures typically associated with the first-order tectonic features,with dissimilarities due to different data and methods used in model *** quantification of model structural similarity can help in interpreting the geophysical properties of Earth's interior and establishing unified models crucial in natural hazard assessment and resource *** we employ the complex wavelet structural similarity index measure(CW-SSIM)active in computer image processing to analyze the structural similarity of four lithospheric velocity models of Chinese mainland published in the past *** take advantage of this method in its multiscale definition and insensitivity to slight geometrical distortion like translation and scaling,which is particularly crucial in the structural similarity analysis of velocity models accounting for uncertainty and *** results show that the CW-SSIM values vary in different model pairs,horizontal locations,and *** variations in the inter-model CW-SSIM are partly owing to different databases in the model generation,the difference of tomography methods may significantly impact the similar structural features of models,such as the low similarities between the full-wave based FWEA18 and other three models in northeastern *** finally suggest potential solutions for the next generation of tomographic modeling in different areas according to corresponding structural similarities of existing models.

关键词： structural similarity lithosphere tomography velocity model Chinese mainland

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

携带横向轨道角动量的时空局域波包的传输特性(特邀)

引用

光学学报 2024年第10期44卷 294-300页

作者：张年佳曹前 Chong andy 詹其文上海理工大学光电信息与计算机工程学院上海200093 釜山国立大学物理系韩国釜山46241

光学轨道角动量(OAM)可以纵向OAM的形式存在于空间涡旋光束中,或以横向OAM的形式存在于时空光涡旋波包中。与涡旋光束不同,时空光涡旋波包在传播过程中同时受到衍射和色散效应的影响,造成波包在时空域内的展宽,并且时空光涡旋波包携带... 详细信息

光学轨道角动量(OAM)可以纵向OAM的形式存在于空间涡旋光束中,或以横向OAM的形式存在于时空光涡旋波包中。与涡旋光束不同,时空光涡旋波包在传播过程中同时受到衍射和色散效应的影响,造成波包在时空域内的展宽,并且时空光涡旋波包携带的横向OAM也会在传播过程中分裂。这两点限制了横向OAM在其他研究领域的应用。本文引入并研究了携带横向OAM的三维时空局域波包,此波包可以同时克服衍射与色散效应造成的时空域三维变化。在传播过程中,该时空局域波包的时空域分布不变,且在遇到障碍物后也能快速重新恢复到原有的状态,具有传播不变以及自恢复的特性。本文对时空局域波包的传播过程以及经过障碍物后的恢复过程进行了数值模拟仿真,证实了其传播不变特性和自恢复特性。这种携带横向OAM的三维时空局域波包为横向OAM未来的利用提供了新的机遇,有望应用于光通信、量子光学、光学成像等领域。

关键词：横向光学轨道角动量三维时空局域波包传播不变自恢复

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

The Spectral Characterization of Blue Spinel and Other Blue Gemstones with the Alexandrite Effect

引用

宝石和宝石学杂志（中英文） 2024年第4期26卷 69-76页

作者： Jiling Zhou Chengsi Wang Xishan Zhao Yunqi Yang andy Hsitien Shen Gemmological Institute China University of GeosciencesWuhan 430074China Hubei Gems and Jewelry Engineering Technology Research Center Wuhan 430074China Shenzhen Research Institute of China University of Geosciences Shenzhen 518000China Guangzhou CUG Gems and Jewelry Testing Co. Ltd.Guangzhou 510000China

In gemmology,the term“Alexandrite effect”is used to describe colour change phenomenon when a gemstone is observed under different light sources,usually between daylight and incandescent *** definition of the Alexandrite effect is constantly being broadened with new discovery of gem *** traditional definition of the Alexandrite effect attributing the colour change phenomenon to the presence of two maximum transmission regions and a maximum absorption region in the absorption *** this study,7 blue spinels and 5 blue gemstones(including tanzanite,kyanite,fluorite,and 2 sapphires)showing the Alexandrite effect were *** goal is to explain the cause of blue-to-violet Alexandrite effect and the spectral features causing such colour *** the UV-Vis spectra,all samples showed a maximum absorption peak in the range of 534-610 nm,within the green region to orange *** traditional explanation of green to red Alexandrite effect required a transmission window in the red region;however,some of our samples did not show this transmission window and the blue-to-violet Alexandrite effect was still ***,it is incomplete to explain the mechanism of the Alexandrite effect according to their characteristic absorption spectra,a systematic study based on modern colour science and colour perception in human vision is required to elucidate the blue-to-violet Alexandrite effect.

关键词： blue spinel Alexandrite effect absorption spectrum

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

携带横向轨道角动量的时空局域波包的传输特性（特邀）

引用

光学学报 2024年第10期 302-308页

作者：张年佳曹前 Chong andy 詹其文上海理工大学光电信息与计算机工程学院釜山国立大学物理系

光学轨道角动量（OAM）可以纵向OAM的形式存在于空间涡旋光束中，或以横向OAM的形式存在于时空光涡旋波包中。与涡旋光束不同，时空光涡旋波包在传播过程中同时受到衍射和色散效应的影响，造成波包在时空域内的展宽，并且时空光涡旋波... 详细信息

光学轨道角动量（OAM）可以纵向OAM的形式存在于空间涡旋光束中，或以横向OAM的形式存在于时空光涡旋波包中。与涡旋光束不同，时空光涡旋波包在传播过程中同时受到衍射和色散效应的影响，造成波包在时空域内的展宽，并且时空光涡旋波包携带的横向OAM也会在传播过程中分裂。这两点限制了横向OAM在其他研究领域的应用。本文引入并研究了携带横向OAM的三维时空局域波包，此波包可以同时克服衍射与色散效应造成的时空域三维变化。在传播过程中，该时空局域波包的时空域分布不变，且在遇到障碍物后也能快速重新恢复到原有的状态，具有传播不变以及自恢复的特性。本文对时空局域波包的传播过程以及经过障碍物后的恢复过程进行了数值模拟仿真，证实了其传播不变特性和自恢复特性。这种携带横向OAM的三维时空局域波包为横向OAM未来的利用提供了新的机遇，有望应用于光通信、量子光学、光学成像等领域。

关键词：横向光学轨道角动量三维时空局域波包传播不变自恢复

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

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

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

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：