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Introduction to the Special Issue on ComputerModeling for Smart Cities Applications
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作者 Wenbing Zhao Chenxi Huang Yizhang Jiang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1015-1017,共3页
A significant fraction of the world’s population is living in cities. With the rapid development ofinformation and computing technologies (ICT), cities may be made smarter by embedding ICT intotheir infrastructure. B... A significant fraction of the world’s population is living in cities. With the rapid development ofinformation and computing technologies (ICT), cities may be made smarter by embedding ICT intotheir infrastructure. By smarter, we mean that the city operation will be more efficient, cost-effective,energy-saving, be more connected, more secure, and more environmentally friendly. As such, a smartcity is typically defined as a city that has a strong integration with ICT in all its components, includingits physical components, social components, and business components [1,2]. 展开更多
关键词 SMART typically SMART
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Improving the Accuracy of Vegetation Index Retrieval for Biomass by Combining Ground-UAV Hyperspectral Data-A New Method for Inner Mongolia Typical Grasslands
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作者 Ruochen Wang Jianjun Dong +3 位作者 Lishan Jin Yuyan Sun Taogetao Baoyin Xiumei Wang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期387-411,共25页
Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored t... Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored the original spectral information of typical grasslands in Inner Mongolia and examined the influence of spectral information on aboveground biomass(AGB)estimation.In order to improve the accuracy of vegetation index inversion of grassland AGB,this study combined ground and Unmanned Aerial Vehicle(UAV)remote sensing technology and screened sensitive bands through ground hyperspectral data transformation and correlation analysis.The narrow band vegetation indices were calculated,and ground and airborne hyperspectral inversion models were established.Finally,the accuracy of the model was verified.The results showed that:(1)The vegetation indices constructed based on the ASD FieldSpec 4 and the UAV were significantly correlated with the dry and fresh weight of AGB.(2)The comparison between measured R^(2) with the prediction R^(2) indicated that the accuracy of the model was the best when using the Soil-Adjusted Vegetation Index(SAVI)as the independent variable in the analysis of AGB(fresh weight/dry weight)and four narrow-band vegetation indices.The SAVI vegetation index showed better applicability for biomass monitoring in typical grassland areas of Inner Mongolia.(3)The obtained ground and airborne hyperspectral data with the optimal vegetation index suggested that the dry weight of AGB has the best fitting effect with airborne hyperspectral data,where y=17.962e^(4.672x),the fitting R^(2) was 0.542,the prediction R^(2)was 0.424,and RMSE and REE were 57.03 and 0.65,respectively.Therefore,established vegetation indices by screening sensitive bands through hyperspectral feature analysis can significantly improve the inversion accuracy of typical grassland biomass in Inner Mongolia.Compared with ground monitoring,airborne hyperspectral monitoring better reflects the inversion of actual surface biomass.It provides a reliable modeling framework for grassland AGB monitoring and scientific and technological support for grazing management. 展开更多
关键词 Aboveground biomass inversion model vegetation index unmanned aerial vehicle typical grassland
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Analysis on Typical Spatio-temporal Characteristics of Open-cast Mining and Its Countermeasures
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作者 Qingyou AO Qiang FU +2 位作者 Zhihua LIU Yu XUN Lin LIN 《Asian Agricultural Research》 2024年第5期20-24,共5页
In order to deal with the special spatio-temporal environmental changes encountered in the process of open-cast mining,taking Huolinhe No.1 Open-cast Mine as the research object,this paper studied its typical problems... In order to deal with the special spatio-temporal environmental changes encountered in the process of open-cast mining,taking Huolinhe No.1 Open-cast Mine as the research object,this paper studied its typical problems in river reconstruction and cultural relics protection.The study focused on eight key core aspects,including the design optimization of the spatial layout of the mining area,the accurate estimation of the mineral resources reserves,the scientific theoretical demonstration of the mining scale,the fine analysis and calculation of the stripping ratio,the comprehensive consideration of the transport distance and efficiency,the accurate judgment of the best time for the implementation of the transformation,the analysis and evaluation of the slope stability,and the overall planning of the production system.The results show that the extracted problem-solving strategies and scheme system for special mining conditions can not only provide specific and practical guidance for Huolinhe No.1 Open-cast Mine,but also serve as a valuable reference and practical reference for other open-cast mine enterprises facing similar challenges. 展开更多
关键词 Open-cast mining in the mining area Typical space-time environment River reconstruction Cultural relics protection Spatial layout
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Analysis of a Typical Case of Meteorological Service in Tangpu Reservoir
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作者 Quan SHAN Yuxin DING +2 位作者 Tingting GU Jinxin WANG Kai TANG 《Meteorological and Environmental Research》 2024年第2期44-47,共4页
The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better... The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models. 展开更多
关键词 Tangpu Reservoir Meteorological service Continuous rain Analysis of a typical case
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Towards Energy-Efficient Autonomous Driving: A Multi-Objective Reinforcement Learning Approach
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作者 Xiangkun He Chen Lv 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第5期1329-1331,共3页
Dear Editor, With the development of automobile industry and artificial intelligence(AI) domains, autonomous vehicles(AVs) are becoming a reality and promise to revolutionize human mobility [1]–[3]. The decision-maki... Dear Editor, With the development of automobile industry and artificial intelligence(AI) domains, autonomous vehicles(AVs) are becoming a reality and promise to revolutionize human mobility [1]–[3]. The decision-making system of AVs is crucial, which is typically required to trade off multiple competing objectives. For example,when determining driving policies. 展开更多
关键词 typically driving artificial
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A case of atypical neurological symptoms and high cerebro-spinal fluid acetone level due to transdermal exposure to isopropanol
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作者 Côme Fruit Sophie Guillotin +5 位作者 Marie Wolfrum Thomas Lanot Florent Battefort Pierre Girardie Marie Rafiq Nicolas Delcourt 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2023年第2期152-154,共3页
Dear editor, Isopropanol, also named 2-propanol or isopropyl alcohol(IPA), is a colorless, volatile liquid found in numerous household chemicals, such as cleaners and disinfectants, which typically contain a 70% solut... Dear editor, Isopropanol, also named 2-propanol or isopropyl alcohol(IPA), is a colorless, volatile liquid found in numerous household chemicals, such as cleaners and disinfectants, which typically contain a 70% solution of IPA in water. IPA is also extensively used in industry and laboratories as a solvent. 展开更多
关键词 ACETONE typically ALCOHOL
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Clues from a missense mutation of the adenosine A1 receptor gene associated with early-onset Parkinson’s disease
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作者 Sergi Ferré Leonardo Pardo Francisco Ciruela 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第10期2204-2205,共2页
Parkinson’s disease (P D) is a com plex neu rodegenerative disorder for which ra re and common genetic variants contribute to disease risk,onset,and progression.The genetic contribution to PD can be classified mainly... Parkinson’s disease (P D) is a com plex neu rodegenerative disorder for which ra re and common genetic variants contribute to disease risk,onset,and progression.The genetic contribution to PD can be classified mainly in,first,rare DNA variants that are highly penetrant and therefore causal,which are typically associated with monogenic PD;and second,more common risk polymorphic variants,which individually exert a small increase in the risk of the disease,which are usually identified in the most prevalent and apparently sporadic PD (Blauwendraat et al.,2020). 展开更多
关键词 typically DEGENERATIVE
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AusMed Brings Game-Changing Healthcare Innovations from Hong Kong,China to the World——An interview with Christine Yip,Founder and CEO of AusMed Global Limited
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作者 Guo Yan 《China's Foreign Trade》 2023年第4期23-26,共4页
“As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expens... “As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expensive specialty equipment,we proudly introduce the world’s first-of-its-kind handheld breath ketone(BrAce)analyser,empowered by our patented disruptive photonic sensing technologies.These innovations are aimed at providing a more effective approach to managing diabetes and ketosis(fat metabolism),”said Christine Yip,founder and CEO of AusMed Global Limited,during a recent interview with China’s Foreign Trade magazine. 展开更多
关键词 KETONE RINGS typically
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The Three Cs:China,Culture and Civilization
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作者 ROBERT WALKER 《China Today》 2023年第11期48-51,共4页
Steeped in a civilization featuring inclusivity and peaceful nature,China seeks exchanges and mutual learning among civilizations rather than cultural hegemony.WHILE claiming its preeminent global economic status,Chin... Steeped in a civilization featuring inclusivity and peaceful nature,China seeks exchanges and mutual learning among civilizations rather than cultural hegemony.WHILE claiming its preeminent global economic status,China has also come to assert its equivalent position in world politics and diplomacy,typically representing the interests of the developing world. 展开更多
关键词 mutual typically representing
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节日的意义
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作者 吴自江 《疯狂英语(新悦读)》 2023年第5期19-24,75,共7页
主题语境:节日感想篇幅:311词建议用时:6分钟This week,my social media feed was flooded with pictures of a festival that is typically celebrated in March in Nepal.For me,the festival,which is a Nepalese tradition,had less... 主题语境:节日感想篇幅:311词建议用时:6分钟This week,my social media feed was flooded with pictures of a festival that is typically celebrated in March in Nepal.For me,the festival,which is a Nepalese tradition,had less regional significance and was largely cultural,providing me with a day to play with color and water with my beloved family and friends. 展开更多
关键词 typically FESTIVAL celebrated
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The Response of Anomalous Vertically Integrated Moisture Flux Patterns Related to Drought and Flood in Southern China to Sea Surface Temperature Anomaly 被引量:2
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作者 董娜 徐祥德 +4 位作者 蔡雯悦 王春竹 赵润泽 魏凤英 孙婵 《Journal of Tropical Meteorology》 SCIE 2023年第2期179-190,共12页
With the extreme drought(flood)event in southern China from July to August in 2022(1999)as the research object,based on the comprehensive diagnosis and composite analysis on the anomalous drought and flood years from ... With the extreme drought(flood)event in southern China from July to August in 2022(1999)as the research object,based on the comprehensive diagnosis and composite analysis on the anomalous drought and flood years from July to August in 1961-2022,it is found that there are significant differences in the characteristics of the vertically integrated moisture flux(VIMF)anomaly circulation pattern and the VIMF convergence(VIMFC)anomaly in southern China in drought and flood years,and the VIMFC,a physical quantity,can be regarded as an indicative physical factor for the"strong signal"of drought and flood in southern China.Specifically,in drought years,the VIMF anomaly in southern China is an anticyclonic circulation pattern and the divergence characteristics of the VIMFC are prominent,while those are opposite in flood years.Based on the SST anomaly in the typical draught year of 2022 in southern China and the SST deviation distribution characteristics of abnormal draught and flood years from 1961 to 2022,five SST high impact areas(i.e.,the North Pacific Ocean,Northwest Pacific Ocean,Southwest Pacific Ocean,Indian Ocean,and East Pacific Ocean)are selected via the correlation analysis of VIMFC and the global SST in the preceding months(May and June)and in the study period(July and August)in 1961-2022,and their contributions to drought and flood in southern China are quantified.Our study reveals not only the persistent anomalous variation of SST in the Pacific and the Indian Ocean but also its impact on the pattern of moisture transport.Furthermore,it can be discovered from the positive and negative phase fitting of SST that the SST composite flow field in high impact areas can exhibit two types of anomalous moisture transport structures that are opposite to each other,namely an anticyclonic(cyclonic)circulation pattern anomaly in southern China and the coastal areas of east China.These two types of opposite anomalous moisture transport structures can not only drive the formation of drought(flood)in southern China but also exert its influence on the persistent development of the extreme weather. 展开更多
关键词 drought in southern China in 2022 VIMFC anomaly high impact areas of SST anomaly anomalous moisture transport circulation pattern typical drought and flood years
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Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China
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作者 LI Dongmei WEN Qing +1 位作者 QI Yue ZHANG Pingyu 《Chinese Geographical Science》 SCIE CSCD 2023年第4期616-633,共18页
As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainab... As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions. 展开更多
关键词 rural function depopulation trade-off and synergy typical black soil region Northeast China
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Characteristics of sub-synchronous oscillation in grid-connected wind farm system
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作者 Yan Gong Qi Huang +1 位作者 Dong-Sheng Cai Bamisile Olusola Olorunfemi 《Journal of Electronic Science and Technology》 EI CSCD 2023年第4期91-101,共11页
With the rapid development of wind power, wind turbines are accompanied by a large quantity of power electronic converters connected to the grid, causing changes in the characteristics of the power system and leading ... With the rapid development of wind power, wind turbines are accompanied by a large quantity of power electronic converters connected to the grid, causing changes in the characteristics of the power system and leading to increasingly serious sub-synchronous oscillation (SSO) problems, which urgently require the generalized classification and characterization of the emerging oscillation problems. This paper classifies and characterizes the emerging types of SSO caused by grid-connected wind turbines to address these issues. Finally, the impact of the typical system parameters changes on the oscillation pattern is analyzed in depth to provide effective support for the subsequent suppression and prevention of SSO. 展开更多
关键词 CHARACTERISTICS CLASSIFICATION Sub-synchronous oscillation(SSO) Typical system parameters Wind farm
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Changes of spring wind erosion based on wind erosion climate factor in the black soil region of Northeast China
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作者 YAN Ping JI Sheng-tai +5 位作者 LI Xiu-fen ZHU Hai-xia WANG Liang-liang ZHAI Mo WANG Ping ZHAO Hui-ying 《Journal of Mountain Science》 SCIE CSCD 2023年第6期1712-1724,共13页
The dry and windy climate and low ground cover in spring in the black soil region of Northeast China make the soil strongly affected by wind erosion,which seriously threatens the food security and ecological security ... The dry and windy climate and low ground cover in spring in the black soil region of Northeast China make the soil strongly affected by wind erosion,which seriously threatens the food security and ecological security of this region.In this paper,based on the daily observation data of 124 meteorological stations in study area from 1961 to 2020,seasonal and monthly wind erosion climate factor(C)in spring(March to May)were calculated by using the method proposed by the Food and Agriculture Organization of the United Nations(FAO),the wind erosion characterization in spring were systematically analyzed based on C by various statistical analysis methods.The results showed that in the past 60 years,spring wind erosion climate factor(CSp)and monthly C of the whole region and each province(region)all showed highly significant decreasing trend,but they began to show rebounded trend in the middle or late 2000s.CSp of the study area showed a significant upward trend since 2008 with an increase of 4.59(10a)^(-1).The main contributors to this upward trend are the changes of C in March and in April.For the four provinces(regions),CSp in Heilongjiang,Jilin,Liaoning and eastern Inner Mongolia all showed rebounded since 2008,2011,2008 and 2009,respectively.The rebounded trend of CSp in eastern Inner Mongolia was the most obvious with a tendency rate of 11.27(10a)^(-1),and its mutation occurred after 1984.The rebound trend of CSp in Heilongjiang Province takes the second place,with a trend rate of 4.72(10a)^(-1),but there’s no obvious time mutation characteristics.The spatial characteristics of CSpand monthly C are similar,showing decreasing characteristics centered on the typical black soil belt of Northeast China.Compared with 1961-1990,in the period from 1991 to 2020,the proportion of high value areas(CSp>35,monthly C>10)has decreased to varying degrees,while the proportion of low value areas(CSp≤10,monthly C≤4)has increased.The trends of seasonal and monthly C in 82.2%~87.7%of the stations show significant decreases at 95%confidence level.CSp is closely related to wind speed at 2m height,temperature difference,minimum temperature and precipitation in the same period,of which the correlation between CSp and wind speed is the strongest,indicating that the main control factor for CSp in the study area is wind speed,but the impact of the change of temperature and precipitation on CSp cannot be ignored. 展开更多
关键词 Wind erosion climate erosivity Spatiotemporal 1characteristics Climate change Rebounded trend Typical black soil region Northeast China
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Sedimentary architecture and distribution of intra-platform shoal in sequence framework of Permian Changxing Formation in central Sichuan Basin,SW China
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作者 WANG Dong LIU Hong +7 位作者 TANG Song BAI Jinhao ZHOU Gang LI Zhengyong LIANG Feng TAN Xiucheng GENG Chao YANG Ying 《Petroleum Exploration and Development》 SCIE 2023年第2期388-403,共16页
Based on the comprehensive analysis of core, thin section, logging and seismic data, this study carried out the identification and comparison of Permian Changxing Formation sequences, clarified the typical sedimentary... Based on the comprehensive analysis of core, thin section, logging and seismic data, this study carried out the identification and comparison of Permian Changxing Formation sequences, clarified the typical sedimentary architectures of intra-platform shoal, investigated the vertical and horizontal development and distribution of intra-platform shoal in each sequence, and thus established the sedimentary evolution model of shoal body. The study results are reflected in four aspects.First, there are two complete third-order sequences(SQ1 and SQ2) in Changxing Formation in central Sichuan Basin. SQ1 is generally thick in the north and thin in the south, and SQ2 shows a thickness differentiation trend of “two thicknesses and three thinnesses”. Second, the Changxing Formation in central Sichuan Basin mainly develops intra-platform shoal, inter-shoal sea and intra-platform depression subfacies. In the vertical direction, the intra-platform shoal mainly presents two typical sedimentary sequences: stable superposed and high-frequency interbedded. Third, the stable superimposed sedimentary sequence is developed in the shoal belt at the edge of intra-platform depression, which is composed of two shoal-forming periods and located in the highstand systems tracts(HSTs) of SQ1 and SQ2. The high-frequency interbedded sedimentary sequence is developed in the southern shoal belt of intra-platform depression, which is composed of four shoal-forming periods and mainly located in the HST of SQ2. Fourth, during the SQ1 deposition, the intra-platform shoal was mainly developed at the edge of the intra-platform depression on the north side of the study area, and the inter-shoal sea subfacies was mainly developed on the south side. During the SQ2 deposition, the intra-platform shoal was widely developed in the area, forming two nearly parallel intra-platform shoal belts. The study results provide direction and ideas for exploration of Changxing Formation intra-platform shoal reservoirs in central Sichuan Basin. 展开更多
关键词 Sichuan Basin Permian Changxing Formation intra-platform shoal sequence stratigraphic framework typical sedimentary sequence sedimentary evolution model
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Automatic Extraction of Typical River Vegetation Elements Based on Low-altitude Remote Sensing Images
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作者 Xiaomeng ZHANG Hao WU 《Meteorological and Environmental Research》 CAS 2023年第1期70-75,共6页
Based on low-altitude remote sensing images,this paper established sample set of typical river vegetation elements and proposed river vegetation extraction technical solution to adaptively extract typical vegetation e... Based on low-altitude remote sensing images,this paper established sample set of typical river vegetation elements and proposed river vegetation extraction technical solution to adaptively extract typical vegetation elements of river basins.The main research of this paper were as follows:(1)a typical vegetation extraction sample set based on low-altitude remote sensing images was established.(2)A low-altitude remote sensing image vegetation extraction model based on the focus perception module was designed to realize the end-to-end automatic extraction of different types of vegetation areas of low-altitude remote sensing images to fully learn the spectral spatial texture information and deep semantic information of the images.(3)By comparison with the baseline method,baseline method with embedded focus perception module showed an improvement in the precision by 7.37%and mIoU by 49.49%.Through visual interpretation and quantitative calculation analysis,the typical river vegetation adaptive extraction network has effectiveness and generalization ability,consistent with the needs of practical applications of vegetation extraction. 展开更多
关键词 altitude remote sensing images Deep learning Semantic segmentation Typical river vegetation extraction Attention
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科学家更喜欢研究外表可爱的动物(英文)
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作者 佘巧耘 《大学英语》 2017年第4期54-54,57,共2页
The koala^1 is a cutie,but does it steal^2 too much of the limelight^3?A new study adds quantitative detail to an ongoing debate over whether such"conservation mascots^4"receive publicity and funding to the detrime... The koala^1 is a cutie,but does it steal^2 too much of the limelight^3?A new study adds quantitative detail to an ongoing debate over whether such"conservation mascots^4"receive publicity and funding to the detriment of^5 animals typically deemed less attractive. 展开更多
关键词 FUNDING ATTRACTIVE DEBATE steal CONSERVATION typically AUSTRALIA ongoing PROCEEDINGS Fleming
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奥陶纪-志留纪边界附近火山活动记录:来华南周缘钾质斑脱岩的信息 被引量:42
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作者 胡艳华 孙卫东 +3 位作者 丁兴 汪方跃 凌明星 刘健 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第12期3298-3308,共11页
扬子地台内奥陶纪顶部的五峰组到志留纪底部的龙马溪组间存在着多个粘土岩层。前人研究结果认为这些粘土岩层为钾质斑脱岩,是火山喷发的凝灰质物质在海相环境沉积、蚀变的产物。这些斑脱岩广泛分布于扬子地台周缘,对理解奥陶纪-志留纪... 扬子地台内奥陶纪顶部的五峰组到志留纪底部的龙马溪组间存在着多个粘土岩层。前人研究结果认为这些粘土岩层为钾质斑脱岩,是火山喷发的凝灰质物质在海相环境沉积、蚀变的产物。这些斑脱岩广泛分布于扬子地台周缘,对理解奥陶纪-志留纪时华南所处的大地构造位置和相应的构造事件具有重要的意义。本文对采自扬子地台内湖北宜昌地区和贵州桐梓地区奥陶纪-志留纪界线剖面的斑脱岩层进行了矿物学及地球化学工作,旨在判定其形成的构造环境。矿物学研究表明上述岩石除了含有粘土矿物外,还含有石英、长石、黑云母、磷灰石、锆石等中酸性岩浆岩中的常见矿物,属典型的钾质斑脱岩。本文利用在风化过程中不活动元素对斑脱岩的原岩进行了恢复,结果也表明其原岩为中酸性火山岩,包括安山岩-英安岩-及流绞岩等。微量元素特征显示多数样品具有典型的岛弧火山岩的特征,很可能与北面早古生代秦岭洋的闭合过程中的板块俯冲有关,也可能是早古生代在华南板块东南缘外侧存在的一古老洋壳向华南板块的俯冲。有一个样品(YC0711)没有Nb的负异常,但是具有明显的Ti负异常,在Th/Yb-Nb/Yb判别图上落在岛弧区附近,其原岩可能是富铌玄武岩之类的特殊岛弧岩石。火山活动的峰期为晚奥陶世赫南特阶时代,与地质历史上第二大的生物大灭绝事件同时。前人认为该生物灭绝事件与冈瓦纳冰川有关。考虑到华南以及欧洲、北美等地均出现大规模晚奥陶世-早侏罗纪钾质斑脱岩,奥陶纪-志留纪边界的火山事件是具有全球规模的,所喷发的岩石多是富含挥发份的中酸性岩,对大气圈和生物圈具有十分重要的影响,本文认为火山活动很可能是造成晚奥陶世的生物大灭绝事件和冈瓦纳冰川的主要诱导因素。 展开更多
关键词 奥陶纪 志留纪 边界 火山活动 活动记录 华南板块 钾质斑脱岩 信息 Yangtze Block mass extinction VOLCANIC rocks 扬子地台 晚奥陶世 typical characteristics South China plate tectonic setting 事件 生物大灭绝 VOLCANIC activity geological events
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广西北海红树林土壤放线菌的分离与鉴定(摘要)(英文) 被引量:6
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作者 廖振林 刘菁 +3 位作者 陈建宏 钟毓娟 蒋莲秀 陈森洲 《Agricultural Science & Technology》 CAS 2010年第5期194-196,共3页
[目的]鉴定广西北海红树林土壤放线菌的物种多样性。[方法]从广西北海红树林土壤中分离、筛选10株典型放线菌菌株,提取基因组DNA,进行16S rDNA PCR扩增与测序,并构建进化树。[结果]通过Blast比对,10株放线菌属于2个属,其中8株为链霉菌属... [目的]鉴定广西北海红树林土壤放线菌的物种多样性。[方法]从广西北海红树林土壤中分离、筛选10株典型放线菌菌株,提取基因组DNA,进行16S rDNA PCR扩增与测序,并构建进化树。[结果]通过Blast比对,10株放线菌属于2个属,其中8株为链霉菌属(80%),2株为拟诺卡氏菌属(20%)。[结论]广西北海红树林土壤蕴藏着种类丰富的放线菌。 展开更多
关键词 广西 北海 红树林土壤 土壤放线菌 分离与鉴定 ACTINOBACTERIA Identification of forest soil species diversity 拟诺卡氏菌属 GENOMIC DNA 物种多样性 构建进化树 放线菌菌株 SUCCESSFUL different Blast比对 链霉菌属 rDNA typical
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典型波纹翅片单元流动与传热特性的数值研究 被引量:4
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作者 王维斌 傅宪辉 +2 位作者 吴茂刚 冯茺蔚 牛洪成 《机械设计与制造》 北大核心 2010年第12期198-200,共3页
以两种典型的波纹翅片单元为研究对象,在合理简化条件下给出了物理模型和数学模型,通过流固界面的传热耦合,对不同进口风速下波纹翅片单元的流动及传热和阻力特性进行了数值研究。通过对传热系数,Nu数、压降以及涡量分布的对比分析,结... 以两种典型的波纹翅片单元为研究对象,在合理简化条件下给出了物理模型和数学模型,通过流固界面的传热耦合,对不同进口风速下波纹翅片单元的流动及传热和阻力特性进行了数值研究。通过对传热系数,Nu数、压降以及涡量分布的对比分析,结果表明:人字形翅片的传热性能优于波浪形翅片,而流动阻力性能却没有明显的劣势,其主要原因是翅片流场中涡流的产生与耗散存在差异。 展开更多
关键词 典型 波纹翅片 单元 流动及传热 传热特性 数值研究 TYPICAL TRANSFER of flow 阻力性能 阻力特性 研究对象 物理模型 涡量分布 数学模型 流固界面 对比分析 传热性能 传热系数 传热耦合
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