检索结果-南通市图书馆

Changes in the depths of seasonal freezing and thawing and their effects on vegetation in the Three-River Headwater Region of the Tibetan Plateau

引用

Journal of Mountain Science 2019年第12期16卷 2810-2827页

作者： WANG Rui DONG Zhi-bao ZHOU Zheng-chao school of geography and Tourism Shaanxi Normal University

Frozen ground degradation plays an important role in vegetation growth and activity in high-altitude cold *** study estimated the spatiotemporal variations in the active layer thickness(ALT)of the permafrost region and the soil freeze depth(SFD)in the seasonally frozen ground region across the Three Rivers Source Region(TRSR)from 1980 to 2014 using the Stefan equation,and differentiated the effects of these variations on alpine vegetation in these two *** results showed that the average ALT from 1980 to 2014 increased by23.01 cm/10 a,while the average SFD decreased by 3.41 cm/10 a,and both changed intensively in the transitional zone between the seasonally frozen ground and *** 1982-2014,the increase in the normalized difference vegetation index(NDVI)and the advancement of the start of the vegetation growing season(SOS)in the seasonally frozen ground region(0.0078/10 a,1.83 d/10 a)were greater than those in the permafrost region(0.0057/10 a,0.39 d/10 a).The results of the correlation analysis indicated that increases in the ALT and decreases in the SFD in the TRSR could lead to increases in the NDVI and advancement of the *** soil moisture played a critical role in vegetation growth in association with the increasing ALT and decreasing *** NDVI for all vegetation types in the TRSR except for alpine vegetation showed an increasing trend that was significantly related to the SFD and *** the study period,the general frozen ground conditions were favorable to vegetation growth,while the average contributions of ALT and SFD to the interannual variation in the NDVI were greater than that of precipitation but less than that of temperature.

关键词： Frozen soil depth Active layer thickness Alpine vegetation Climate warming Three Rivers Source Region

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

Quartz-Hosted Fluid Inclusions Characteristics and Their Implications for Fluvial Deposits along the Changjiang River

引用

Journal of Earth Science 2020年第3期31卷 571-581页

作者： Zhenqiang Ji Chendong Ge Mengyang Zhou Nan Zhang Key Laboratory of Coast and Island development(Nanjing University)of Ministry of Education Key Laboratory of Coast and Island Development ofJiangsu ProvinceSchool of Geography and Ocean ScienceNanjing UniversityNanjing 210023China

The characteristics of quartz-hosted fluid inclusions in fluvial sediments from five locations in the upstream,midstream,and estuary of the Changjiang River,China,are *** sources of sediments are discussed concerning their differences in the shape,size,number,gas percentage and genetic type of quartz-hosted fluid *** upstream to downstream,the characteristics of quartz-hosted fluid inclusions in sediments are *** fluid inclusion types in the samples from upstream to estuary are gradually *** sediment influx from the tributaries of the Changjiang River makes new types of quartz-hosted fluid inclusions in the downstream and *** terms of the number and size,most quartz-hosted fluid inclusions are concentrated in the range of 2-4μm in diameters and 10-150 in number per 10^-3 mm^*** number and size ranges of the fluid inclusions from different positions are also *** fluid inclusions in the sample collected from the Shigu,upstream of the Changjiang River,are 2-18μm in size,with the number of 2-166 per 10^-3 mm^*** the samples collected from Yibin,Yichang and Wuhan,the sizes of fluid inclusions are 2-15,2-10,2-12μm,with the number of 1-270,2-220,and 1^-308 per 10^-3 mm^3,*** proportion of primary fluid inclusions in the sample of the upstream(14%)is higher than that of the midstream(6%-8%)and the estuary(5%),suggesting that different types of source rocks have been input into the river by the *** characteristics of quartz-hosted fluid inclusions in the fluvial sediments could offer a new perspective for exploration of the source of sediments.

关键词： quartz-hosted fluid inclusions morphological characteristics fluid inclusion types source of fluvial sediments Changjiang River

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

Climate change and plague history in Europe

引用

Science China Earth Sciences 2018年第2期61卷 163-177页

作者： Ricci P.H.YUE Harry F.LEE The Department of geography The University of Hong Kong International Center for China development Studies The University of Hong Kong

Previous research that reported the linkage between climate change and plague activity primarily refers to the immediate effect of short-term climatic variation. Yet, decades of discussion about the climate-plague association cannot determine the precise role of climate in shaping plague dynamics. One reason for this discrepancy originates from the narrow selection of spatio-temporal settings for comprehensive analysis of the correlation, leading to a limited consideration of the complexity of possible *** analyzing a 414-year long record of plague outbreak in pre-industrial Europe and the corresponding climatic data in multi-scale,we find little evidence to support climate-plague correlation in(1) both climatic variations and large-scale climatic phenomena,(2)both country scale and continental scale,(3) annual to inter-annual scale, and(4) both linear and non-linear analytic approaches. The null-result should not be viewed as a general rejection of other recent findings related to climate-plague association; nevertheless,it suggests that a wider consideration of scales, sensitivity checks and consideration of contexts should be included in explaining and predicting plague transmission under contemporary global climate conditions.

关键词： Plague Climate change Scale Pre-industrial period Europe

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

Simulating Evolution of a Loess Gully Head with Cellular Automata

引用

Chinese Geographical Science 2015年第6期25卷 765-774页

作者： LIU Xiaojing TANG Guo'an YANG Jianyi SHEN Zhou PAN Ting school of geography Science Nanjing Normal University

This paper presents a new method for simulating the evolution of a gully head in a loess catchment with cellular automata(CA) based on the Fisher discriminant. The experimental site is an indoor loess catchment that was constructed in a fixed-intensity rainfall erosion test facility. Nine high-resolution digital elevation model(DEM) data sets were gathered by close range photogrammetry during different phases of the experiment. To simulate the evolution of the catchment gully head, we assumed the following. First, the 5th and 6th DEM data sets were used as a data source for acquiring the location of the catchment gully head and for obtaining spatial variables with GIS spatial analysis tools. Second, the Fisher discriminant was used to calculate the weight of the spatial variables to determine the transition probabilities. Third, CA model was structured to simulate the evolution of the gully head by iterative looping. The status of the cell in the CA models was dynamically updated at the end of each loop to obtain realistic results. Finally, the nearest neighbor, G-function, K-function, Moran′s I and fractal indexes were used to evaluate the model results. Overall, the CA model can be used to simulate the evolution of a loess gully head. The experiment demonstrated the advantages of the CA model which can simulate the dynamic evolution of gully head evolution in a catchment.

关键词： cellular automata digital elevation model (DEM) gully head loess catchment point pattem

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

Ammonia pyrolysis oxidation excited by nanosecond pulsed discharge:Global/fluid models hybrid solution

引用

Journal of Energy Chemistry 2025年第1期100卷 385-396页

作者： Mingming Zhang Hanyu Wu Qi Chen Jiaxin Yang Bonan Liu school of Mechanical Electronic and Control Engineering Beijing Jiaotong University China University of Petroleum

The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution ***,the stable products of plasma-assisted oxidative pyrolysis of ammonia are *** results show that the consumption of NH3/O2and the production of N2/H2change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low ***,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is *** on the reaction path analysis,the simplified mechanism is *** detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified ***,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key *** results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of *** consumption of NH3by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O（1S）.However,within the sheath,almost all reactions do not ***,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and ***,the discharge interval has little effect on the sheath structure and gas mixture *** research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore th

关键词： Nanosecond pulsed discharge Ammonia Oxidative pyrolysis Fluid model Global model

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

Retrieval of urban land surface component temperature using multi-source remote-sensing data

引用

Journal of Central South University 2013年第9期20卷 2489-2497页

作者：郑文武曾永年 Spatial Information Technology and sustainable development Research Center School of Geoscience and Info-Physics Central South University school of Resource Environment and Tourism Management Hengyang Normal University

The components of urban surface cover are diversified,and component temperature has greater physical significance and application values in the studies on urban thermal *** the multi-angle retrieval algorithm of component temperature has been matured gradually,its application in the studies on urban thermal environment is restricted due to the difficulty in acquiring urban-scale multi-angle thermal infrared ***,based on the existing multi-source multi-band remote sensing data,access to appropriate urban-scale component temperature is an urgent issue to be solved in current studies on urban thermal infrared remote ***,a retrieval algorithm of urban component temperature by multi-source multi-band remote sensing data on the basis of MODIS and Landsat TM images was proposed with expectations achieved in this work,which was finally validated by the experiment on urban images of Changsha,*** results show that：1） Mean temperatures of impervious surface components and vegetation components are the maximum and minimum,respectively,which are in accordance with the distribution laws of actual surface temperature; 2） High-accuracy retrieval results are obtained in vegetation component ***,through a contrast between retrieval results and measured data,it is found that the retrieval temperature of impervious surface component has the maximum deviation from measured temperature and its deviation is greater than 1 ℃,while the deviation in vegetation component temperature is relatively low at 0.5 ℃.

关键词： component temperature urban thermal environment multi-source remote sensing thermal infrared remote sensing

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

Tourist management in national parks in the Czech-German borderland:Bohemian ’Switzerland’ and Saxon‘Switzerland’

引用

Journal of Mountain Science 2020年第12期17卷 2853-2879页

作者： Krzysztof KOLODZIEJCZYK Department of Regional geography and Tourism Institute of Geography and Regional DevelopmentFaculty of Earth Sciences and Environmental ManagementUniversity of WroclawWroclaw 50-137Poland

In the article tourist management in two national parks in the Czech-German borderland are being compared,namely Bohemian ’Switzerland’(also known as Czech ’Switzerland’) and Saxon’Switzerland’.Situated on either side of the state border,they feature the same type of geographical *** accessibility,transborder links and the hiking trail network are analyzed using methodology sourced from graph *** result of the analyses is a classification of tourist hubs and tourist centers,as well as an indication of the main directions of tourist *** German national park is decidedly more accessible but with a detrimental effect on the natural environment primarily due to its fragmentation by a dense network of tourist *** both parks trails enter the core zone(in theory a strict protection area) but this occurs on a larger scale on the German *** the Czech national park a greater number of positive examples of managing tourist movements can be ***,larger areas managed for dispersion,or from which tourists are generally excluded,are located there.

关键词： National parks Tourist management Tourist trails Bohemian’Switzerland’ Saxon’Switzerland’

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

Penetrating remote sensing:Next-generation remote sensing for transparent earth

引用

The Innovation 2023年第6期4卷 15-16页

作者： Lizhe Wang Boxin Zuo Yuan Le Yifu Chen Jun Li International Research Center of Big Data for sustainable development Goals Beijing 100094China school of Computer Science China University of GeosciencesWuhan 430074China school of geography and Information Engineering China University of GeosciencesWuhan 430074China

Building upon a unified theoretical framework(based on electromagnetic principles and considering interactions with the Earth’s subsurface materials),we consider a synergistic blend of high-spectral,electromagnetic,and diverse multi-physics techniques to introduce a new concept of penetrating remote *** seamlessly amalgamating the interplay between multiple physical fields,penetrating remote sensing allows us to understand the Earth from its surface to its interior,effectively uncovering information about the planet’s internal *** outcome of this new concept encompasses detailed imagery and three-dimensional models,offering insights into the distribution,structure,properties,and dynamic behavior of materials residing within the *** empowers us to delve into the profound layers of the Earth,unveiling its structural composition and evolutionary *** deeper understanding encompasses vital aspects concerning the Earth’s crust,mantle,and core,comprehending temperature distributions,flow patterns,and other crucial information that enriches our knowledge of the planet’s interior.

关键词： Earth planet interior

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

Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive

引用

International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 214-220页

作者： Tanakorn Phoo-ngernkham Prinya Chindaprasirt Vanchai Sata Saengsuree Pangdaeng Theerawat Sinsiri sustainable Infrastructure Research and development Center Department of Civil EngineeringFaculty of EngineeringKhon Kaen University school of Civil Engineering Institute of EngineeringSuranaree University of Technology

The effect of Portland cement （OPC） addition on the properties of high calcium fly ash geopolymer pastes was investigated in the paper. OPC partially replaced fly ash （FA） at the dosages of 0, 5%, 10%, and 15% by mass of binder. Sodium silicate （Na2SiO3） and sodium hydroxide （NaOH） solutions were used as the liquid portion in the mixture： NaOH 10 mol/L, Na2SiO3/NaOH with a mass ratio of 2.0, and alkaline liquid/binder （L/B） with a mass ratio of 0.6. The curing at 60℃ for 24 h was used to accelerate the geopolymerization. The setting time of all fresh pastes, porosity, and compressive strength of the pastes at the stages of 1, 7, 28, and 90 d were tested. The elastic modulus and strain capacity of the pastes at the stage of 7 d were determined. It is revealed that the use of OPC as an additive to replace part of FA results-in the decreases in the setting time, porosity, and strain capacity of the paste specimens, while the compressive strength and elastic modulus seem to increase.

关键词： geopolymers Portland cement fly ash compressive strength porosity elastic moduli

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

Tourism management in national parks:Sumava and Bayerischer Wald(Bavarian Forest)in the Czech-German borderland

引用

Journal of Mountain Science 2021年第9期18卷 2213-2239页

作者： Krzysztof KOŁODZIEJCZYK Department of Regional geography and Tourism Institute of Geography and Regional DevelopmentFaculty of Earth Sciences and Environmental ManagementUniversity of Wroclaw54-152 WroclawPoland

Along the Czech-German border there are four national parks,two Czech and two German,arranged in cross-border‘pairs’.This article focuses on the southern‘pair’formed by the parks of?umava and Bayerischer Wald(Bavarian Forest).The aim is to evaluate and compare tourism organization in their areas,taking into account selected aspects of management:the network of hiking trails with its related infrastructure,transport accessibility,a typology of tourist centers,as well as directions and destinations of tourist *** on the results,it can be concluded that the availability of geographical space for tourists is much greater in the German than in the Czech national park,and the tourism infrastructure is clearly more extensive there,including the network of tourist *** is mainly due to the longer and fairly uninterrupted development of tourism in this area.?umava National Park can be identified as a model in terms of how to adjust the directions of tourist movements and the layout of the tourist trail network to the needs of natural *** the basis of observations in both national parks,it is possible to indicate various solutions that,after appropriate adaptation,may bring benefits to other protected areas.

关键词： National parks Tourism management Tourism infrastructure Tourist trails Sumava Bayerischer Wald(Bavarian Forest)

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：