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Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China 被引量:2
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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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Interactions between Vegetation and Climatic Factors in Typical Arid and Humid Regions of China Based on NDVI 被引量:1
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作者 李洪利 孙善磊 +3 位作者 孙杰 黄珏 顾人颖 骆杨 《Meteorological and Environmental Research》 CAS 2010年第2期48-52,56,共6页
According to the distribution of arid and humid regions in China,the typical arid region (Erjina),the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) and the typical humid region (Poyang Lake basin... According to the distribution of arid and humid regions in China,the typical arid region (Erjina),the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) and the typical humid region (Poyang Lake basin) were selected as the study areas.Based on NDVI data from 1982 to 2000 and meteorological observing data of three study areas from 1981 to 2000,the interactions between vegetation NDVI and climatic factors (temperature and precipitation) in typical arid and humid regions were discussed in this study.The results showed that in the responses of vegetation to climatic factors,vegetation in the typical arid region (Erjina) was more sensitive to precipitation,while vegetation in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau) was more sensitive to both temperature and precipitation,and vegetation in the typical humid region (Poyang Lake basin) was more sensitive to temperature.As for effects of vegetation on climatic factors,there was a remarkable negative correlation between vegetation NDVI in the past winter and temperature in the present summer,and also a significant positive correlation between vegetation NDVI in the past winter and precipitation in the present summer.However,in the typical semi-arid/semi-humid region (Guanzhong basin/Loess Plateau),there was a significant positive correlation between vegetation NDVI in the present spring and temperature in the present summer. 展开更多
关键词 typical arid and humid region NDVI Climatic factor Temperature PRECIPITATION China
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Dynamic of Chinas cultivated land and landcover changes of its typical regions based on remote sensing data 被引量:1
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作者 张佳华 董文杰 +2 位作者 王长耀 刘纪远 姚凤梅 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第3期183-186,210,共5页
Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigati... Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigation showed that the whole distribution of the cultivated land shifted to Northeast and Northwest China, and as a result, the ecological quality of cultivated land dropped down. The seacoast and cultivated land in the area of Yellow River Mouth expanded by an increasing rate of 0.73 kma-1, with a depositing rate of 2.1 kma-1. The desertification area of the dynamic of Horqin Sandy Land increased from 60.02% of the total land area in1970s to 64.82% in1980s but decreased to 54.90% in early 1990s. As to the change of North Tibet lakes, the water area of the Namu Lake decreased by 38.58 km2 from year 1970 to 1988, with a decreasing rate of 2.14 km2a-1. 展开更多
关键词 Remote sensing data Cultivated land Landcover change typical ecological regions China
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Groundwater quality and land use change in a typical karst agricultural region:a case study of Xiaojiang watershed,Yunnan 被引量:15
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作者 JIANG Yongjun YUAN Daoxian +3 位作者 XIE Shiyou LI Linli ZHANG Gui HE Raosheng 《Journal of Geographical Sciences》 SCIE CSCD 2006年第4期405-414,共10页
Taking the typical karst agricultural region, Xiaojiang watershed in Luxi of Yurman Province as a research unit, utilizing the groundwater quality data in 1982 and 2004, the aerial photos in 1982 and TM images in 2004... Taking the typical karst agricultural region, Xiaojiang watershed in Luxi of Yurman Province as a research unit, utilizing the groundwater quality data in 1982 and 2004, the aerial photos in 1982 and TM images in 2004, supported by the GIS, we probe into the law and the reason of its space-time change of the groundwater quality over the past 22 years in the paper. The results show: (1) There were obvious temporal and spatial changes of groundwater quality during the past 22 years. (2) Concentrations of NH4^+, SO4^2- , NO3, NO2^-, Cl^- and the pH value, total hardness, total alkalinity increased significantly, in which NH4^2-, NO3, and NO2^- of groundwater exceeded the drinking water standards as a result of non-point pollution caused by the expansion of cultivated land and mass use of the fertilizer and pesticide. (3) Oppositely, Ca^2+ and HCO3^- showed an obvious decline trend due to forest reduction and degradation and stony desertification. Meantime, there was a dynamic relation between the groundwater quality change and the land use change. 展开更多
关键词 groundwater quality space-time change land use change typical karst agricultural region GIS Xiaojiang watershed
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Integrated Prevention and Control System for Soil Erosion in Typical Black Soil Region of Northeast China 被引量:1
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作者 SUN Li-ying CAI Qiang-guo +1 位作者 CHEN Sheng-yong HE Ji-jun 《Asian Agricultural Research》 2012年第12期102-107,共6页
The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to d... The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to direct threats to national food security and regional sustainable development. Therefore, it is necessary to summarize integrated prevention and control experience of small watersheds in black soil region of Northeast China. Tongshuang small watershed, a typical watershed in rolling hills of typical black soil areas in Northeast China, is selected as the study area. Based on nearly 50 years' experience in prevention and control of soil and water loss, the structures and overall benefits of an integrated prevention and control system for soil and water loss are investigated. Then, the 'three defense lines' tri-dimensional protection system with reasonable allocation of different types of soil and water control measures from the hill top to gully is systematically analyzed. The first line on the top hill can weaken and block uphill runoff and sediment, hold water resources and improve soil property. The second line on the hill can truncate slope length, slow down the runoff velocity and reduce erosion energy. The third line in the gully is mainly composed of waterfall engineering, which can inhibit soil erosion and restore land resources. The 'three defense lines' system is feasible for soil and water loss control of small watersheds in the typical black soil region of Northeast China. Through the application of the in Tongshuang small watershed, There are effective improvements in ecological conditions in Tongshuang small watershed after the application of 'three defense lines' soil and water control system. Moreover, the integrated treatment paradigm for soil and water loss in typical black soil region is compared with that in loess region. The results of this study could offer references and experiences for other small watersheds in typical black soil region of Northeast China. 展开更多
关键词 typical BLACK SOIL region Small WATERSHED SOIL and
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Regions and Their Typical Paradigms for Soil and Water Conservation in China 被引量:2
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作者 DANG Xiaohu SUI Boyang +5 位作者 GAO Siwen LIU Guobin WANG Tao WANG Bing NING Duihu BI Wei 《Chinese Geographical Science》 SCIE CSCD 2020年第4期643-664,共22页
China is experiencing conflicts between its large population and scarce arable land,and between a demand for high productivity and the severe soil erosion of arable land.Since 1949,China has committed to soil and wate... China is experiencing conflicts between its large population and scarce arable land,and between a demand for high productivity and the severe soil erosion of arable land.Since 1949,China has committed to soil and water conservation(SWC),for which eight regions and 41 subregions have been developed to improve the environment and increase land productivity.To obtain information from the regional planning and strategies for SWC and to explore whether SWC practices simultaneously contribute to soil conservation,ecosystem functioning,and the livelihoods of local farmers,and to summarize the successful experiences of various SWC paradigms with distinct characteristics and mechanisms of soil erosion,this paper systematically presents seven SWC regions(excluding the Tibetan Plateau region)and 14 typical SWC paradigms,focusing on erosion mechanisms and the key challenges or issues in the seven regions as well as on the core problems,main objectives,key technologies,and the performance of the 14 typical paradigms.In summary,the 14 typical SWC paradigms successfully prevent and control local soil erosion,and have largely enhanced,or at least do not harm,the livelihoods of local farmers.However,there remain many challenges and issues on SWC and socioeconomic development that need to be addressed in the seven SWC regions.China,thus,still has a long way to go in successfully gaining the win-win objective of SWC and human aspects of development. 展开更多
关键词 regions for soil and water conservation soil erosion dryland farming collapse erosion karst rocky desertification typical paradigm for soil and water conservation
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Dynamic influence of Holocene characteristics on vadose water in typical region of central North China Plain 被引量:1
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作者 ZHANG Wei SHI Jian-sheng +3 位作者 XU Jian-ming LIU Ji-chao DONG Qiu-yao FAN Shu-xian 《Journal of Groundwater Science and Engineering》 2016年第3期247-258,共12页
In the typical region of central North China Plain, vadose sediments are Holocene sediment strata. With samples from field drillings, the study analyzes the sedimentary characteristics of vadose zone. The study takes ... In the typical region of central North China Plain, vadose sediments are Holocene sediment strata. With samples from field drillings, the study analyzes the sedimentary characteristics of vadose zone. The study takes the content of silty sand as the basis for sedimentary environment analysis, and the content of clay and sand as the sensitive indicator for sedimentary characteristics. Combining palynology analysis, the study divides vadose zone from top to bottom into diluvia oxbow lacustrine sediments, lacustrine sediments, lacustrine and swamp sediments, weak palaeohydrodynamic lacustrine sediments and alluvial sediments. Based on the sedimentary characteristics of Holocene strata, it analyzes the changes across depth of vadose zone water potential and matrix potential, obtaining the influence of vadose zone sedimentary characteristics on the migration of water in typical region of central North China Plain. 展开更多
关键词 typical region of North China Plain Vadose zone Sedimentary characteristics Vadose zone water potential
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Effect of climatic change on surface environments in the typical region of Horqin Sandy Land
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作者 Long Ma TingXi Liu +2 位作者 HongLan Ji YanYun Luo LiMin Duan 《Research in Cold and Arid Regions》 2010年第2期143-153,共11页
The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface env... The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas. 展开更多
关键词 Horqin Sandy Land typical region surface environment climatic change RESPONSE climatic factor impact index
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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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我国区域典型城市国际化水平的定量分析及对策思考
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作者 汪来喜 赵梦娟 李世杰 《区域经济评论》 CSSCI 北大核心 2024年第3期114-124,共11页
采用层次分析法,从经济开放、科技创新、国际影响和城市宜居四个层面构建准则层,选取18个指标评价14个区域典型城市的国际化水平,结果表明:(1)区域典型城市的国际化水平总体评分及经济开放指标评价呈现东部最优、西部次优,而中部最靠后;... 采用层次分析法,从经济开放、科技创新、国际影响和城市宜居四个层面构建准则层,选取18个指标评价14个区域典型城市的国际化水平,结果表明:(1)区域典型城市的国际化水平总体评分及经济开放指标评价呈现东部最优、西部次优,而中部最靠后;(2)科技创新上,东部科技创新实力强劲,中部城市的武汉处于第二位次城市组别,西部城市成都处于第一层次城市群里;(3)国际影响上,第一层次东部占据前三城市,中部4个城市均居于第三层次,西部城市成都处于第一层次里第四位次;(4)城市宜居上,东中西部典型城市分值差别不大。 展开更多
关键词 城市国际化 区域典型城市 层次分析法
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突出流行性还是稀缺性?——地理标志农产品地区典型性与广告诉求方式的匹配效应研究
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作者 王丹 李林竹 李艳军 《管理工程学报》 CSSCI CSCD 北大核心 2024年第3期76-90,共15页
地理标志农产品的本质特征在于产品与产地的关联性,但不同的地理标志农产品,消费者对其产品与产地关系的联想即地区典型性存有差异。针对地区典型性不同的地理标志农产品,如何采用配套的广告诉求方式以提升品牌传播的有效性?为此,本研... 地理标志农产品的本质特征在于产品与产地的关联性,但不同的地理标志农产品,消费者对其产品与产地关系的联想即地区典型性存有差异。针对地区典型性不同的地理标志农产品,如何采用配套的广告诉求方式以提升品牌传播的有效性?为此,本研究将地区典型性与广告诉求方式相匹配探究其对消费者态度的影响,以及这一影响发生的内在机制与边界条件。四个实验结果表明,当地理标志农产品的地区典型性高时,采用流行性诉求更能引发消费者对产品的积极态度,感知可靠性在其中起中介作用;当地理标志农产品的地区典型性低时,采用稀缺性诉求更能引发消费者对产品的积极态度,感知独特性在其中起中介作用。此外,产品属性在地区典型性与广告诉求方式对消费者产品态度的交互作用中起调节作用,高地区典型性与流行性诉求对消费者产品态度的交互作用在实用性属性下更显著,低地区典型性与稀缺性诉求对消费者产品态度的交互作用在享乐性属性下更显著。本研究为地理标志农产品消费行为研究提供了新的视角,同时对提升地理标志品牌价值及促进地理标志产业均衡发展具有实践意义。 展开更多
关键词 地理标志农产品 地区典型性 广告诉求方式 产品属性 消费者产品态度
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关帝山3个典型森林群落优势种的氮素利用策略差异
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作者 张芸香 吕世琪 +2 位作者 刘泰瑞 李晋芳 郭晋平 《林业科学》 EI CAS CSCD 北大核心 2024年第2期12-20,共9页
【目的】研究关帝山林区华北落叶松林、白桦林和沙棘林3个典型森林群落优势种的新生枝叶氮含量、地上生物量和氮利用效率对5个土壤施氮梯度的差异化响应,阐明3个森林群落优势种不同的氮利用功能特性和氮利用策略,为氮沉降背景下的森林... 【目的】研究关帝山林区华北落叶松林、白桦林和沙棘林3个典型森林群落优势种的新生枝叶氮含量、地上生物量和氮利用效率对5个土壤施氮梯度的差异化响应,阐明3个森林群落优势种不同的氮利用功能特性和氮利用策略,为氮沉降背景下的森林质量提升和精准经营提供理论依据。【方法】采用野外5梯度土壤氮(0、9、18、27和36 g·m^(−2) a^(−1))添加试验的方法,比较3个森林群落优势种和群落总体的新生枝叶氮含量、地上新增生物量和氮利用效率对土壤不同施氮量的响应;采用线性模型拟合地上新增生物量随新生枝叶氮含量、氮利用效率和土壤氮素供应水平的变化过程;通过构建结构方程模型,分析土壤氮添加影响地上新增生物量的作用路径。【结果】3个群落优势种的新生枝叶氮含量总体表现为华北落叶松<白桦<沙棘,新生叶氮含量显著高于新生枝,两者的差异表现为白桦>华北落叶松>沙棘,生长盛期的枝叶氮含量都高于末期,生长期之间的差异也表现为白桦>华北落叶松>沙棘;新生枝和新生叶在生长盛期和末期的氮含量都有随施氮量增加而增加的趋势,但3个优势种的变化表现出显著不同的趋势,饱和施氮量和饱和氮含量均表现为华北落叶松<白桦<沙棘;3个群落新生枝叶生物量都随施氮量的增大而升高,但递增率拟合结果表现为华北落叶松林>沙棘林>白桦林;群落氮利用效率都随施氮量增大而降低,以华北落叶松林的降幅最大,沙棘林最小,也随优势树种枝叶氮储量的升高而降低,以白桦林降幅最大,沙棘林最小;群落优势种和群落类型对群落新生枝叶氮储量和氮素利用效率直接作用显著,也受施氮量的影响,进而正向驱动群落新增生物量积累。【结论】华北落叶松林、白桦林和沙棘林3个森林群落新增生物量的差异主要取决于群落类型及其优势种的差异,直接受群落优势种的氮利用效率和新生枝叶氮含量的影响,并受土壤供氮水平的调节;三者的氮利用策略分异表现在氮需求、氮利用效率、环境氮敏感性、饱和氮供应水平4个方面;依次表现为“低需求-高效率-高敏感-低饱和”、“较低需求-低效率-较高敏感-较低饱和”和“固氮型-高需求-低效率-低敏感-高饱和”3个氮利用策略类型,可为不同氮沉降情境或林地氮含量水平下的林分优势树种选择、结构调控和林地精准管理提供依据。 展开更多
关键词 土壤氮添加 氮利用效率 氮利用策略 优势树种 典型森林群落 关帝山林区
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我国新质生产力的地区差异与时空演变:典型城市的比较研究
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作者 纪玉俊 刘俊成 宋皓 《中国海洋大学学报(社会科学版)》 2024年第5期54-66,共13页
发展新质生产力是推动高质量发展的内在要求和重要着力点。从新质生产力形成的现实路径出发构建新质生产力综合指标体系,对我国典型城市新质生产力发展水平进行测算,并借助核密度估计、Dagum基尼系数和Markov链探究我中国新质生产力的... 发展新质生产力是推动高质量发展的内在要求和重要着力点。从新质生产力形成的现实路径出发构建新质生产力综合指标体系,对我国典型城市新质生产力发展水平进行测算,并借助核密度估计、Dagum基尼系数和Markov链探究我中国新质生产力的时空演变和空间分化趋势。研究表明,样本期内我国新质生产力发展水平总体呈现向好态势,区域间整体呈现“东高西低”格局,东、中、西部地区域间和域内差距呈扩大趋势,时空上呈现极化和空间集聚的格局,且存在明显的“俱乐部趋同”现象和空间外溢效应,可为促进新质生产力的区域间协调发展和因地制宜发展新质生产力提供现实依据。 展开更多
关键词 新质生产力 典型城市 地区差异 时空演变
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中国省域高等教育“放管服”改革政策的审视与优化
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作者 李春林 刘杰美 王聪 《华北理工大学学报(社会科学版)》 2024年第4期74-79,共6页
高等教育“放管服”改革是深化教育行政管理体制改革、转变政府职能的必由之路。以中国省域高等教育“放管服”改革政策文本为研究对象,应用内容分析方法,分别从简政放权、放管结合、优化服务三个方面对政策内容进行分析,将政策的典型... 高等教育“放管服”改革是深化教育行政管理体制改革、转变政府职能的必由之路。以中国省域高等教育“放管服”改革政策文本为研究对象,应用内容分析方法,分别从简政放权、放管结合、优化服务三个方面对政策内容进行分析,将政策的典型特征提炼为:政策文本体例相似且均为联合发文、权力下放呈现一定梯度且强调试点先行、政策推进强化机制创新及营造良好环境。提出了不断完善政策体系、形成政策协同效应、强化政策执行合力等优化对策。 展开更多
关键词 省域 高等教育“放管服”改革 高校办学自主权 政策文本 典型特征
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初始含水率和降雨能量对黑土团聚体溅蚀特征的影响 被引量:1
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作者 张转敏 王彬 +1 位作者 饶伟 王文刚 《水土保持学报》 CSCD 北大核心 2024年第2期68-75,共8页
[目的]为明晰降雨能量和初始含水率对土壤团聚体溅蚀过程机制的影响。[方法]选取东北典型耕层黑土为研究对象,通过人工模拟降雨试验,探讨不同初始含水率、降雨能量和团聚体初始粒径的团粒溅蚀特征。[结果](1)4种初始粒径黑土团聚体的溅... [目的]为明晰降雨能量和初始含水率对土壤团聚体溅蚀过程机制的影响。[方法]选取东北典型耕层黑土为研究对象,通过人工模拟降雨试验,探讨不同初始含水率、降雨能量和团聚体初始粒径的团粒溅蚀特征。[结果](1)4种初始粒径黑土团聚体的溅蚀量均在初始含水率4%时最大,其中初始粒径<0.25 mm团聚体溅蚀量是相同降雨能量下各粒径团聚体溅蚀量的1.21~5.50倍。随初始含水率的增加各初始粒级团聚体溅蚀量呈减小趋势,而初始含水率>25%后则呈增大现象。(2)4种初始粒径黑土团聚体的溅蚀量均随降雨能量的增加而增大。相较于降雨能量305 J/(m^(2)·h)(1 m)条件,当降雨能量增加至909 J/(m^(2)·h)(5 m)时,不同初始粒径团聚体溅蚀量分别增加15.37~20.70(<0.25 mm),52.30~417.60(0.25~1 mm),51.58~359.36(1~3 mm),68.73~777.99倍(3~5 mm)。不同初始粒径黑土团聚体溅蚀量存在明显的阈值,当降雨能量达到529 J/(m^(2)·h)(2 m)以上时,不同降雨能量梯度下的溅蚀量存在显著差异。(3)降雨能量是影响溅蚀量的关键因素。降雨能量对溅蚀量的直接效应为0.811,存在显著正向影响,且相关程度最高;初始含水率和团聚体初始粒径的直接效应分别为0.193和0.352,存在显著负向影响。[结论]研究结果可为东北黑土区坡面土壤侵蚀过程机制研究和土壤侵蚀机理模型构建提供科学依据。 展开更多
关键词 初始含水率 降雨能量 溅蚀量 典型黑土区
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重庆市北碚区天府镇野外地质实习虚拟仿真教学平台的建设探索 被引量:1
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作者 熊益学 葛玉辉 +2 位作者 张云峰 谭兵 郗爱华 《中国地质教育》 2024年第1期106-110,共5页
野外实习是地学类专业的特色,也是培养合格石油、地矿行业人才的重要环节,对夯实专业知识、提升实践技能、厚植地质兴趣、锻炼优良品质发挥着不可替代的作用。“人工智能+”倒逼野外地质实习实现云端化、数字化、虚拟仿真化,以期达到实... 野外实习是地学类专业的特色,也是培养合格石油、地矿行业人才的重要环节,对夯实专业知识、提升实践技能、厚植地质兴趣、锻炼优良品质发挥着不可替代的作用。“人工智能+”倒逼野外地质实习实现云端化、数字化、虚拟仿真化,以期达到实习互动性强、资源保存永久、网络共享便捷的效果。以重庆市北碚区天府镇野外地质露头为基础,构建以西南地区广泛出露的古生代-中生代海相沉积岩为主要内容的地质实习虚拟仿真教学平台,通过典型剖面出露地层的野外产状、岩性及成分特点、古生物种类、构造类型及其形成机制等重点内容的剖析,解决教学过程中学生对远古地质作用现象认识不清、难以根据各种构造关系厘定区域地质发展历史等教学难题,培养学生独立思考及理论联系实际的地质思维能力。该平台的建立不仅能丰富野外地质实习的教学方式、提升教学质量、实现教学资源共享,还能为石油、地矿行业的继续教育提供社会化服务。 展开更多
关键词 虚拟仿真教学 典型地质剖面 野外地质实习 北碚地区
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中国北方典型地区人群活动模式特色数据集
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作者 杨意森 刘盛宇 +4 位作者 梅亚园 周全 赵梅朵 许群 吴思竹 《Chinese Medical Sciences Journal》 CAS CSCD 2024年第1期69-73,I0007,共6页
本文介绍了《典型地区活动模式特色数据集》(Typical Regional Activity Patterns,TRAP),此数据集依托于“大气重污染成因与治理攻关项目”。为了探索大气污染与体力活动的交互效应,我们在空气污染物浓度高于周边地区的典型区域(济南市... 本文介绍了《典型地区活动模式特色数据集》(Typical Regional Activity Patterns,TRAP),此数据集依托于“大气重污染成因与治理攻关项目”。为了探索大气污染与体力活动的交互效应,我们在空气污染物浓度高于周边地区的典型区域(济南市和保定市)收集了9,221名不同职业和生活方式居民连续3天的活动模式数据。TRAP数据集包括人口学指标(人口学、职业信息、个人习惯和居住条件)和体力活动模式数据(活动地点和活动强度)信息。此数据集提供了体力活动模式的暴露测量数据,数据使用者可以根据自己的特定目的将其与各种终点指标匹配。此数据集可为探究中国北方居民活动模式属性提供证据,为跨学科研究人员制定健康教育及健康促进策略和措施提供证据。 展开更多
关键词 活动模式 典型地区 行为监测 大气污染 中国
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中国降水再循环率对全球变暖的响应
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作者 黄必城 雍佳桦 +3 位作者 吴丹 吴永萍 封国林 孙桂全 《冰川冻土》 CSCD 2024年第1期284-297,共14页
中国地域广阔,涵盖了多种气候类型和地形特征,这为降水再循环过程提供了复杂的环境条件,使得在研究降水再循环率特征时难以对区域进行划分和比较。本文利用优化后的降水再循环率评估模型计算中国地区降水再循环率,研究了中国地区降水再... 中国地域广阔,涵盖了多种气候类型和地形特征,这为降水再循环过程提供了复杂的环境条件,使得在研究降水再循环率特征时难以对区域进行划分和比较。本文利用优化后的降水再循环率评估模型计算中国地区降水再循环率,研究了中国地区降水再循环率的变化特征及其对全球变暖的响应。结果表明,1979—2020年,中国降水再循环率具有明显的区域和季节性差异,其中青藏高原的再循环率最高,降水再循环率的大值区和线性增长的区域主要位于非季风区的内陆湿润地区;但在干旱半干旱的西北地区东部,降水再循环率整体偏低的情况下,其线性趋势增加非常显著。通过经验正交函数(EOF)分解的结果发现,降水再循环率的第一模态在2000年之前以负位相为主,而2000年之后以正位相为主,且从九年滑动平均来看降水再循环率呈先增加再减少的趋势。本研究依据降水再循环率的大小和气候倾向率的正负,将中国分出四类降水再循环率区域:降水再循环率较大且呈上升趋势(Ⅰ类),降水再循环率较大且呈下降趋势(Ⅱ类),降水再循环率较小且呈上升趋势(Ⅲ类),降水再循环率较小且呈下降趋势(Ⅳ类),并在四类区域中筛选出八个典型区域来研究降水再循环率对全球变暖的响应。在Ⅰ类和Ⅱ类区域的典型区域中的降水主要受到本地蒸发的影响,在Ⅲ类和Ⅳ类区域的典型区域中,降水与外来水汽输送之间的关系更为密切。在同一类型区域中内外循环各变量对全球变暖的响应值不同,蒸发量和水汽通量散度的变化会影响降水平流贡献和局地蒸发贡献对全球变暖的响应强弱。研究中国不同类型区域内外循环变量对全球变暖响应差异,有助于深化对气候变化影响的认识,为制定相应的气候适应策略提供科学依据。 展开更多
关键词 降水 降水再循环率(PRR) 全球变暖 典型区域
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南方典型红壤区不同枯死率芒萁的水土流失阻控效应
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作者 熊维彬 陈志强 +3 位作者 陈志彪 尚艳琼 冯柳俊 李玮晔 《水土保持研究》 CSCD 北大核心 2024年第2期76-83,共8页
[目的]探究芒萁植丛不同枯死率(100%,50%和0%)下坡面的产流产沙规律,揭示不同生长状态下芒萁的水土流失阻控效果。[方法]采用人工模拟降雨试验,对不同芒萁枯死率下坡面产流产沙过程随雨强的变化特性进行了定量分析。[结果](1)不同降雨... [目的]探究芒萁植丛不同枯死率(100%,50%和0%)下坡面的产流产沙规律,揭示不同生长状态下芒萁的水土流失阻控效果。[方法]采用人工模拟降雨试验,对不同芒萁枯死率下坡面产流产沙过程随雨强的变化特性进行了定量分析。[结果](1)不同降雨强度和芒萁枯死率下径流速率随降雨历时呈前期缓慢或快速增长,后期趋于稳定。较小雨强下,侵蚀速率除裸坡外随降雨历时呈前期缓慢增加、后期趋于稳定状态;较大雨强下,侵蚀速率随降雨历时变化呈前期快速增加,中后期逐渐下降趋于稳定。(2)除2 mm/min雨强下的累积产流量外,其余处理条件下累积产流产沙量差异明显,且产沙量随芒萁枯死率的增加而增加。(3)两种雨强不同处理下坡面累积产流量和累积产沙量关系符合幂函数模型(R2>0.99)。[结论]两种雨强芒萁植丛不同枯死率下径流速率和侵蚀速率随降雨历时变化前期迅速增加、后期逐渐波动稳定,各处理下累积径流量与累积产沙量的函数关系拟合回归效果良好,证实了枯死芒萁亦可在中国南方红壤侵蚀区起到良好的水土流失阻控效果。 展开更多
关键词 模拟降雨 芒萁 产流产沙 水土流失 南方典型红壤区
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典型黑土区防护林带和耕地土壤有机碳分布特征及其影响因素
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作者 谢雷雷 潘理 +4 位作者 李伟珍 师立鹏 刘星雨 王雪誉 王秀伟 《东北林业大学学报》 CAS CSCD 北大核心 2024年第7期71-76,共6页
为了合理开发利用典型黑土、阻控土壤退化、维持耕地产能和可持续利用,选择典型黑土区3个地点的杨树林带和紧邻林带的耕地为研究区,通过测定不同土层的土壤有机碳质量分数、酶活性、化学性质和总球囊霉素质量分数,结合气候因素,分析两... 为了合理开发利用典型黑土、阻控土壤退化、维持耕地产能和可持续利用,选择典型黑土区3个地点的杨树林带和紧邻林带的耕地为研究区,通过测定不同土层的土壤有机碳质量分数、酶活性、化学性质和总球囊霉素质量分数,结合气候因素,分析两种土地利用类型下土壤有机碳质量分数的分布特征及其影响因素。结果表明:(1)林带和耕地土壤有机碳质量分数平均值在克山县和宾县的所有土层均存在显著差异(P<0.05),且林带高于耕地,而辽源市的所有土层土壤均无显著差异(P>0.05)(2)3个地点耕地及辽源市林带土壤有机碳质量分数平均值随着土壤深度的增加而显著降低(P<0.05),而克山县和宾县林带的土层土壤均无显著差异(P>0.05)。(3)林带和耕地土壤有机碳质量分数与β-N-乙酰氨基葡萄糖苷酶活性、β-葡萄糖苷酶活性、总球囊霉素质量分数、全磷质量分数、碱解氮质量分数具有极显著的正相关性(P<0.01);林带土壤有机碳质量分数与pH呈极显著的正相关(P<0.01),与年平均气温和年平均降水量呈显著的负相关(P<0.05),与有效磷质量分数相关性不显著(P>0.05);耕地土壤有机碳与有效磷质量分数呈极显著正相关(P<0.01),与年平均气温、年平均降水量和pH相关性不显著(P>0.05)。(4)影响土壤有机碳质量分数的主要因子为总球囊霉素、碱解氮和全磷,次要因子为年平均气温、年平均降水量、β-N-乙酰氨基葡萄糖苷酶、β-葡萄糖苷酶和pH。 展开更多
关键词 典型黑土区 土地利用类型 防护林带 有机碳 球囊霉素
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