检索结果-南通市图书馆

Ratio of photosynthetically active radiation to global solar radiation above forest canopy in complex terrain: measurements and analyses based on Qingyuan Ker Towers

引用

Ecological Processes 2024年第2期13卷 204-217页

作者： Shuangtian Li Qiaoling Yan Tian Gao Xingchang Wang Qingwei Wang Fengyuan Yu Deliang Lu Huaqi Liu Jinxin Zhang Jiaojun Zhu CAS Key Laboratory of forest Ecology and Silviculture Institute of Applied Ecology Chinese Academy of Sciences Qingyuan forest CERN National Observation and Research Station Chinese Academy of Sciences CAS-CSI Joint Laboratory of research and Development for Monitoring forest Fluxes of Trace Gases and Isotope Elements Institute of Applied Ecology Chinese Academy of Sciences (CAS) University of Chinese Academy of Sciences Center for Ecological research Northeast Forestry University

Background Understanding of the ratio of photosynthetic photon flux density（Qp） to global solar radiation（Rs）(Qp/Rs) is crucial for applying Rsto ecology-related *** studies reported Qp/Rsand its variations based on measurements from a single observatory tower,instead of multi-site-based measurements over complex *** may neglect spatial heterogeneity in the terrain,creating a gap in an understanding of how terrain affects Qp/Rsand how this effect interacts with meteorological *** Here the Qingyuan Ker Towers（three towers in a valley with different terrains:T1,T2,and T3） were utilized to measure Qpand Rsover mountainous forests of Northeast *** airborne LiDAR system was used to generate a digital elevation model,and sky view factor of sectors（SVFs） divided from the field of view of tower's pyranometer was calculated as a topographic factor to explain the variations of Qp/*** The results identified significant differences in Qp/Rsof the three towers at both daily and half-hour scales,with larger differences on clear days than on overcast ***/Rswas positively correlated with SVFsof T1 and T3,while this correlation was negative with that of *** effect of SVFson Qp/Rsinteracted with clearness index,water vapor pressure and solar zenith *** forest-based importance assessment demonstrated that explanation（R2） on Qp/Rswas improved when SVFswas included in the predictor variable set,indicating that incorporating terrain effects enhances the prediction accuracy of Qp/*** improvement in the R2values was more pronounced on clear days than on overcast days,suggesting that the effect of terrain on Qp/Rsdepended on sky *** All findings suggested that Qp/Rsis affected by terrain,and integrating terrain information into existing Qp/Rsmodels is a feasible solution to improve Qp/Rsestimates in mountainous areas.

关键词： Photosynthetic photon flux density Clearness index Water vapor pressure Solar zenith angle Terrain Sky view factor

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

Estimating wood quality attributes from dense airborne LiDAR point clouds

引用

forest Ecosystems 2024年第2期11卷 226-235页

作者： Nicolas Cattaneo Stefano Puliti Carolin Fischer Rasmus Astrup Norwegian institute of Bioeconomy research(NIBIO) Division of Forest and Forest ResourcesHøgskoleveien 81433ÅsNorway

Mapping individual tree quality parameters from high-density LiDAR point clouds is an important step towards improved forest *** present a novel machine learning-based workflow that uses individual tree point clouds from drone laser scanning to predict wood quality indicators in standing *** object reconstruction methods,our approach is based on simple metrics computed on vertical slices that summarize information on point distances,angles,and geometric attributes of the space between and around the *** models use these slice metrics as predictors and achieve high accuracy for predicting the diameter of the largest branch per log (DLBs) and stem diameter at different heights (DS) from survey-grade drone laser *** show that our models are also robust and accurate when tested on suboptimal versions of the data generated by reductions in the number of points or emulations of suboptimal single-tree segmentation *** approach provides a simple,clear,and scalable solution that can be adapted to different situations both for research and more operational mapping.

关键词： UAV laser scanning Wood quality Machine learning Point cloud metrics

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

Kinetics of dense plasma in the field of short laser pulses:A generalized approach

引用

Matter and Radiation at Extremes 2024年第5期9卷 87-92页

作者： V.A.Astapenko V.S.Lisitsa Moscow institute of Physics and Technology(national research University) Institutskii per.9141701 DolgoprudnyiRussia national research Centre“Kurchatov institute ”123182 MoscowRussia national research Nuclear University MEPhI 115409 MoscowRussia

A generalized kinetic model of atomic level populations in an optically dense plasma excited by laser pulses of arbitrary duration is formulated and *** model is based on a nonstationary expression for the probability of excitation of an atomic transition and takes into account the effects of laser pulse penetration into an optically dense medium.A universal formula for the excitation probability as a function of time and propagation length is derived and applied to the case of a Lorentzian spectral profile of an atomic transition excited by a laser pulse with a Gaussian *** features of nonstationary excitation probabilities are presented for different optical depths of the plasma,laser pulse durations,and carrier *** formulas derived here will be useful for the description of atomic populations excited by laser pulses under realistic conditions of dense plasmas.

关键词： laser excitation excited

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

Carbon stock estimation in halophytic wooded savannas of Uruguay:An ecosystem approach

引用

forest Ecosystems 2024年第4期11卷 580-589页

作者： Andres Baietto Andres Hirigoyen Carolina Toranza Franco Schinato Maximiliano Gonzalez Rafael Navarro Cerrillo forest Department Faculty of AgronomyUniversity of the RepublicMontevideoPO 12900Uruguay national research Program of forest Production National Agriculture Research InstituteTacuaremboPO 97000Uruguay Soil and Water Department Faculty of AgronomyUniversity of the RepublicMontevideoPO 12900Uruguay Department of forestry Engineering University of CordobaCordobaPO 14014Spain

Savannas constitute a mixture of trees and shrub patches with a more continuous herbaceous *** contribution of this biome to the soil organic carbon(SOC)and above-ground biomass(AGB)carbon(C)stock globally is ***,they are frequently subjected to land use changes,promoting increases in CO_(2) *** Uruguay,subtropical wooded savannas cover around 100,000 ha,of which approximately 28%is circumscribed to sodic soils(i.e.,subtropical halophytic wooded savannas).Nevertheless,there is little background about the contribution of each ecosystem component to the C stock as well as site-specific allometric *** study was conducted in 5 ha of subtropical halophytic wooded savannas of the national protected area Esteros y Algarrobales del Rio *** work aimed to estimate the contribution of the main ecosystem components(e.g.,soil,trees,shrubs,and herbaceous plants)to the C ***-specific allometric equations for the most frequent tree species and shrub genus were fitted based on basal diameter(BD)and total height(H).The fitted equations accounted for between 77%and 98%of the aerial biomass variance of Netuma affinis and Vachellia *** shrubs(Baccharis sp.),the adjusted equation accounted for 86%of total aerial biomass.C stock for the entire system was 116.71±11.07 Mg·ha^(-1),of which 90.7%was allocated in the soil,8.3%in the trees,0.8%in the herbaceous plants,and 0.2%in the *** results highlight the importance of subtropical halophytic wooded savannas as C sinks and their relevance in the mitigation of global warming under a climate change scenario.

关键词： Carbon stock Climate change Biomass modeling Sodic soils

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-situ warming does not change soil priming effect induced by glucose addition in a temperate forest

引用

Pedosphere 2024年第4期34卷 759-769页

作者： Xiaohan DONG Yunting FANG Dongwei LIU Xin GUAN Kai HUANG Yuqi LIU Qingkui WANG Silong WANG Weidong ZHANG Huitong Experimental Station of forest Ecology CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyShenyang 110016China University of Chinese Academy of Sciences Beijing 101408China Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical forest Huitong National Research Station of Forest EcosystemHuitong 418307China Qingyuan forest Chinese Ecosystem research Network(CERN) National Observation and Research StationShenyang 110016China Key Laboratory of forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016(China)f Key Laboratory of Stable Isotope Techniques and ApplicationsShenyang 110016China Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Shenyang 110016China

Priming effect(PE)on soil organic carbon(SOC)decomposition caused by the addition of organic carbon(C)is an important ecological process in regulating soil C ***,most priming studies are confined to laboratory trials,while the assessment of soil PE under field conditions with variable weather conditions is *** study assessed the direct effects of glucose addition and in-situ warming on the extent of PE under field conditions in a temperate *** evaluated soil PE using 13C-glucose labelling,a simple and novel technique,based on the Keeling plot *** addition significantly enhanced native SOC decomposition and induced strong ***,the effect of in-situ warming on the extent of PE was not *** study confirms the importance of PE in regulating SOC turnover under field conditions.

关键词： lue lblling tchnquegbal wamingrmingt hppidfaty ai solganmattermineralisatn oezme respiration

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

Two-dimensional MOF-based materials:Preparations and applications as electrodes in Li-ion batteries

引用

Journal of Energy Chemistry 2024年第10期97卷 388-418页

作者： Narges Nobakht Seyyed Ahmad Etghani Mohammad Hosseini Seyed Hamed Aboutalebi Condensed Matter national Laboratory Institute for Research in Fundamental Sciences Batt Scout Company School of Biological Sciences Institute for Research in Fundamental Sciences

Two-dimensional(2D) metal-organic frameworks(MOFs) are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable *** promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium ***,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy *** limitations have therefore warranted ongoing research to enhance the performance of 2D *** the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF *** promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical ***,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be *** hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium *** the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid *** synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in *** comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.

关键词： 2D materials 2D metal-organic frameworks Energy storage Li-ion batteries Synthesis

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

Assembly of functional carboxymethyl cellulose/polyethylene oxide/anatase TiO_(2) nanocomposites and tuning the dielectric relaxation, optical, and photoluminescence performances

引用

Journal of Semiconductors 2024年第7期45卷 26-38页

作者： Asmaa M.Ismail Abeer A.Reffaee Fawzy G.El Desouky Spectroscopy Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt Microwave Physics and Dielectrics Department National Research CentreDokkiCairoEgypt Solid State Physics Department Physics Research InstituteNational Research CentreGizaCairo 12622Egypt

Nanocomposite films consisting of carboxymethyl cellulose,polyethylene oxide(CMC/PEO),and anatase titanium diox-ide(TO)were produced by the use of sol-gel and solution casting ***2 nanocrystals were effectively incorporated into CMC/PEO polymers,as shown by X-ray diffraction(XRD)and attenuated total reflectance fourier transform infrared(ATR-FTIR)*** roughness growth is at high levels of TO nanocrystals(TO NCs),which means increasing active sites and defects in CMC/*** differential scanning calorimetry(DSC)thermograms,the change in glass transition temperature(Tg)val-ues verifies that the polymer blend interacts with TO *** increment proportions of TO NCs have a notable impact on the dielectric performances of the nanocomposites,as *** electrical properties of the CMC/PEO/TO nanocomposite undergo significant *** nanocomposite films exhibit a red alteration in the absorption edge as the concentration of TO NCs increases in the polymer *** decline in the energy gap is readily apparent as the weight percentage of TO NCs *** photoluminescence(PL)emission spectra indicate that the sites of the luminescence peak maximums show slight variation;peaks get wider,while their intensities decrease dramatically as the concentration of TO *** nanocomposite materials show potential for multifunctional applications including optoelectronics,antireflection coatings,pho-tocatalysis,light emitting diodes,and solid polymer electrolytes.

关键词： anatase TiO_(2) CMC/PEO nanocomposites optical photoluminescent electrical optoelectronics

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

Sclerodermus alternatusi(Hymenoptera:Bethylidae),a new species from China,parasitizing Monochamus alternatus(Coleoptera:Cerambycidae)

引用

Zoological Systematics 2024年第3期49卷 258-266页

作者： Zhongqi Yang Xiaoyi Wang Zhaoyao Duan Yanlong Zhang Yi’nanZhang Liangming Cao Ke Wei Key Lab of forest Protection National Forestry and Grassland AdministrationEcology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091China research institute of Biological Control Beijing Vocational College of AgricultureBeijing 102442China research institute of forest Protection Yunnan Academy of Forestry and GrasslandKunming 650201China

A new species,Sclerodermus alternatusi Yang,***.(Hymenoptera:Bethylidae),is described and *** cerambycid host,Monochamus alternatus Hope,a severe wood borer attacking many pine trees(Pinus spp.),is also a vector of pine wood nematode,Bursaphelencus xylophilus,which cause severe damages to pine forests in *** new species is a gregarious ectoparasitoid of junior larva of *** number of adult wasps reared from a single host larva ranges from 6 to *** ratio of female to male is 20:*** new parasitoid species has a high potential in using as a biocontrol agent for the wood *** of the new species with comparisons to its related species,*** Yang&Yao and a key to known species of Sclerodermus from China is provided.

关键词： Ectoparasitoid larval parasitoid taxonomy biological control

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

Utilizing sediment grain size characteristics to assess the effectiveness of clay–sand barriers in reducing aeolian erosion in Minqin desert area,China

引用

Journal of Arid Land 2024年第5期16卷 668-684页

作者： SONG Dacheng ZHAO Wenzhi LI Guangyu WEI Lemin WANG Lide YANG Jingyi WU Hao MA Quanlin College of forestry Gansu Agricultural UniversityLanzhou 730070China Gansu Hexi Corridor forest Ecosystem national research Station Gansu Desert Control Research InstituteLanzhou 730070China Linze Inland River Basin research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

The clay–sand barriers in Minqin desert area,China,represent a pioneering windbreak and sand fixation project with a venerable history of 60 ***,studies on evaluating the long-term effectiveness of clay–sand barriers against aeolian erosion,particularly from the perspective of surface sediment grain size,are limited and thus insufficient to ascertain the protective impact of these barriers on regional aeolian *** study focused on the surface sediments(topsoil of 0–3 cm depth)of clay–sand barriers in Minqin desert area to explain their erosion resistance from the perspective of surface sediment grain *** March 2023,six clay–sand barrier sampling plots with clay–sand barriers of different deployment durations(1,5,10,20,40,and 60 a)were selected as experimental plots,and one control sampling plot was set in an adjacent mobile sandy area without sand *** sediment samples were collected from the topsoil of each sampling plot in the study area in April 2023 and sediment grain size characteristics were *** indicated a predominance of fine and medium sands in the surface sediments of the study *** deployment of clay–sand barriers cultivated a fine quality in grain size composition of the regional surface sediments,increasing the average contents of very fine sand,silt,and clay by 30.82%,417.38%,and 381.52%,*** trend became markedly pronounced a decade after the deployment of clay–sand *** effectiveness of clay–sand barriers in erosion resistance was manifested through reduced wind velocity,the interception of sand flow,and the promotion of fine surface sediment *** particles such as medium,coarse,and very coarse sands predominantly accumulated on the external side of the barriers,while finer particles such as fine and very fine sands concentrated in the upwind(northwest)region of the *** contrast,the contents of finest particles such as silt and clay were higher in the downwind

关键词： clay-sand barriers sediment grain size grain size distribution aeolian erosion windbreak and sand fixation Minqin desert area

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 rice cultivar on greenhouse-gas emissions from rice-fish co-culture

引用

The Crop Journal 2024年第3期12卷 888-896页

作者： Kexin Xie Mengjie Wang Xiaodan Wang Fengbo Li Chunchun Xu Jinfei Feng Fuping Fang China national Rice research institute Hangzhou 310006ZhejiangChina

In aquaculture,co-culturing rice with fish may mitigate greenhouse-gas *** this study,co-culture of four rice cultivars in a laboratory-scale rice–fish system reduced CH_(4)and N_(2)O emissions relative to fish *** in CH_(4)and N_(2)O emissions among rice cultivars primarily stem from the differential effects of rice plants on plant-mediated CH_(4)transport,CH_(4)oxidation and nitrogen absorption.

关键词： Greenhouse gas emissions Aquaculture Rice-fish system Rice cultivar

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：