期刊文献+
共找到1,000篇文章
< 1 2 50 >
每页显示 20 50 100
Automatic extraction and structuration of soil–environment relationship information from soil survey reports 被引量:8
1
作者 WANG De-sheng LIU Jun-zhi +3 位作者 ZHU A-xing WANG Shu ZENG Can-ying MA Tianwu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第2期328-339,共12页
In addition to soil samples, conventional soil maps, and experienced soil surveyors, text about soils(e.g., soil survey reports) is an important potential data source for extracting soil–environment relationships. Co... In addition to soil samples, conventional soil maps, and experienced soil surveyors, text about soils(e.g., soil survey reports) is an important potential data source for extracting soil–environment relationships. Considering that the words describing soil–environment relationships are often mixed with unrelated words, the first step is to extract the needed words and organize them in a structured way. This paper applies natural language processing(NLP) techniques to automatically extract and structure information from soil survey reports regarding soil–environment relationships. The method includes two steps:(1) construction of a knowledge frame and(2) information extraction using either a rule-based method or a statistic-based method for different types of information. For uniformly written text information, the rule-based approach was used to extract information. These types of variables include slope, elevation, accumulated temperature, annual mean temperature, annual precipitation, and frost-free period. For information contained in text written in diverse styles, the statistic-based method was adopted. These types of variables include landform and parent material. The soil species of China soil survey reports were selected as the experimental dataset. Precision(P), recall(R), and F1-measure(F1) were used to evaluate the performances of the method. For the rule-based method, the P values were 1, the R values were above 92%, and the F1 values were above 96% for all the involved variables. For the method based on the conditional random fields(CRFs), the P, R and F1 values for the parent material were, respectively, 84.15, 83.13, and 83.64%; the values for landform were 88.33, 76.81, and 82.17%, respectively. To explore the impact of text types on the performance of the CRFs-based method, CRFs models were trained and validated separately by the descriptive texts of soil types and typical profiles. For parent material, the maximum F1 value for the descriptive text of soil types was 90.7%, while the maximum F1 value for the descriptive text of soil profiles was only 75%. For landform, the maximum F1 value for the descriptive text of soil types was 85.33%, which was similar to that of the descriptive text of soil profiles(i.e., 85.71%). These results suggest that NLP techniques are effective for the extraction and structuration of soil–environment relationship information from a text data source. 展开更多
关键词 soil–environment relationship TEXT natural LANGUAGE processing extraction STRUCTURATION
下载PDF
Updating conventional soil maps by mining soil–environment relationships from individual soil polygons 被引量:4
2
作者 CHENG Wei ZHU A-xing +1 位作者 QIN Cheng-zhi QI Feng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第2期265-278,共14页
Conventional soil maps contain valuable knowledge on soil–environment relationships.Such knowledge can be extracted for use when updating conventional soil maps with improved environmental data.Existing methods take ... Conventional soil maps contain valuable knowledge on soil–environment relationships.Such knowledge can be extracted for use when updating conventional soil maps with improved environmental data.Existing methods take all polygons of the same map unit on a map as a whole to extract the soil–environment relationship.Such approach ignores the difference in the environmental conditions represented by individual soil polygons of the same map unit.This paper proposes a method of mining soil–environment relationships from individual soil polygons to update conventional soil maps.The proposed method consists of three major steps.Firstly,the soil–environment relationships represented by each individual polygon on a conventional soil map are extracted in the form of frequency distribution curves for the involved environmental covariates.Secondly,for each environmental covariate,these frequency distribution curves from individual polygons of the same soil map unit are synthesized to form the overall soil–environment relationship for that soil map unit across the mapped area.And lastly,the extracted soil–environment relationships are applied to updating the conventional soil map with new,improved environmental data by adopting a soil land inference model(SoLIM)framework.This study applied the proposed method to updating a conventional soil map of the Raffelson watershed in La Crosse County,Wisconsin,United States.The result from the proposed method was compared with that from the previous method of taking all polygons within the same soil map unit on a map as a whole.Evaluation results with independent soil samples showed that the proposed method exhibited better performance and produced higher accuracy. 展开更多
关键词 update CONVENTIONAL SOIL map soil–environment relationshipS knowledge extraction INDIVIDUAL SOIL POLYGONS
下载PDF
The harmonious relationship between land use and environment in Xi’an 被引量:3
3
作者 XUE Dongqian MA Beibei ZHANG Xiaojun 《Journal of Geographical Sciences》 SCIE CSCD 2006年第2期183-191,共9页
In this paper we adopt annual land use conditions change data, land sifting data, social, economic and population data and environment information of nine districts and four counties in Xi'an city from 1980 to 2000 t... In this paper we adopt annual land use conditions change data, land sifting data, social, economic and population data and environment information of nine districts and four counties in Xi'an city from 1980 to 2000 to analyze its structural and degree change of land use since the 1980s, and calculate the benefits and transformation of land use type. The results show that the non-agricultural land increased rapidly, especially the urban and rural residential spots and industrial and mining (RIM) land use increased mostly rapidly, an increase of 64%. Meanwhile, the intensity of land exploitation was accelerating, land was transformed to industries with better benefit and areas experiencing faster urbanization process. By analyzing the harmonious degree of land exploitation in economic and environmental aspects, we find out that the land use imbalance mainly existed in the municipal area of Xi'an, and the imbalance index of land use based on GDP and non-agricultural population were respectively 12.37 and 14.67 in 2000, which were far higher than those in other regions. Nevertheless the environmental harmonious degree in the municipal area of Xi'an ranges between 0.6 and 0.8, which was better than that of suburban area. Some proposals addressing to the problems of harmonious level in all scales, resources utilization, projects management and feasibility analysis and intensive urbanization are also put forward. 展开更多
关键词 land use environment harmonious relationship COUNTERMEASURE Xi'an city
下载PDF
Research on Coupling Relationship between Social Economy and Ecological Environment in Jinghe County of Aiby Lake Basin,Xinjiang 被引量:4
4
作者 Lai Fengbing Sun Hu +1 位作者 Chen Shujiang Ren Shuang 《Meteorological and Environmental Research》 CAS 2014年第11期38-41,45,共5页
Based on the theory of sustainable development,using the theory and method of coupling relationship,the main city of Aiby Lake basin——Jinghe County in Xinjiang is selected. Based on the analyses of natural condition... Based on the theory of sustainable development,using the theory and method of coupling relationship,the main city of Aiby Lake basin——Jinghe County in Xinjiang is selected. Based on the analyses of natural condition,population growth,land use type and ecological environment,the comprehensive evaluation index systems of socio-economic development level and eco-environment quality in Jinghe County are constructed. Using principal component analysis,a comprehensive evaluation of socio-economic development level and ecological environment quality in Jinghe County is conducted by combining with Excel. Their coupling relationship is studied,and quantitative coordination degree between social economy and ecological environment in Jinghe County is obtained. The results show that in recent 50 years,socio-economic development level in Jinghe County is rising,but the ecological environment quality is falling. Their coupling degree C changes during [- 1. 260, + 0. 482],in other words,their coupling relationship is changing between " reluctant coordination" and " not coordination". After entering into the 21 stcentury,their coupling relationship is basically " reluctant coordination". On this basis,the existing problems in the process of sustainable development in Jinghe County are analyzed,and the suggestions about promoting coordinated development between social economy and ecological environment are put forward. 展开更多
关键词 Social economy Ecological environment Coupling relationship Jinghe County China
下载PDF
Floristic composition and edaphic relationships in ferruginous campo rupestre reference ecosystems
5
作者 G.Wilson FERNANDES Letícia RAMOS +3 位作者 Dario C.PAIVA Jéssica CUNHA-BLUM Vanessa Matos GOMES Daniel NEGREIROS 《Journal of Mountain Science》 SCIE CSCD 2024年第3期719-733,共15页
Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferrugin... Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferruginous campo rupestre(rupestrian grassland known as Canga in Brazil),are even more susceptible to severe impacts due to their extreme habitat conditions and low resilience.The determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological restoration.We proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic composition.We described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and soils.All three habitats showed high diversity of plant species and many endemic species,such as Chamaecrista choriophylla,Cuphea pseudovaccinium,Lychnophora pinaster,and Vellozia subalata.The distribution of vegetation was strongly related with the edaphic characteristics,with a set of species more adapted to high concentration of base saturation,fine sand,organic carbon,and iron,while another set of species succeeded in more acidic soils with higher S and silt concentration.We provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local conditions.Failure to recognize the floristic composition of each particular habitat can lead to inappropriate restoration,increased habitat homogenization and increased loss of biodiversity and ecosystem services.This study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats,as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem. 展开更多
关键词 Canga Ecological restoration Extreme ecosystem Non-forest ecosystems Rupestrian grassland Taxon environment relationships
下载PDF
Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China 被引量:4
6
作者 ZHAO Peng QU Jianjun +3 位作者 XU Xianying YU Qiushi JIANG Shengxiu ZHAO Heran 《Journal of Arid Land》 SCIE CSCD 2019年第3期461-476,共16页
Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mec... Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mechanism(s)driving vegetation succession,especially in the ecologically fragile areas.In this study,based on the quantitative analysis of plant community and environmental factors in 68 plots at 10 different transects in the Minqin oasis-desert ecotone(ODE)of northwestern China,we investigated desert vegetation distribution and species-environment relationships using multivariate analysis.Two-way indicator species analysis(TWINSPAN),detrended correspondence analysis(DCA),and canonical correspondence analysis(CCA)methods were used.A total of 28 species,belonging to 27 genera in 8 families,were identified.Chenopodiaceae,Zygophyllaceae,Gramineae,and Leguminosae were the largest families.Annual and perennial herbs accounted for 28.60%of the total number of plants,while shrubs(42.90%)were the most dominant.Nitraria tangutorum was the constructive species of the desert plant community.We divided the 68 plots surveyed in this study into 7 community types,according to the results of TWINSPAN.The distribution of these 7 communities in the DCA ordination graph showed that species with a similar ecotype were clustered together.Results of CCA indicated that groundwater was the dominant factor influencing vegetation distribution,while distance between plot and oasis(Dis)and soil electrical conductivity(EC)were the local second-order factors.Our study suggests that optimizing the utilization of groundwater in oases is key to controlling the degradation of desert vegetation.The favorable topographic conditions of sand dunes should be fully utilized for vegetal dune stabilization,and the influence of soil salinity on the selection of afforestation tree species should be considered. 展开更多
关键词 TWINSPAN classification ORDINATION DESERT plant GROUNDWATER oasis-desert ECOTONE species-environment relationship Minqin
下载PDF
Gorgan Bay: a microcosm for study on macrobenthos speciesenvironment relationships in the southeastern Caspian Sea 被引量:1
7
作者 GHASEMI Amir Faraz TAHERI Mehrshad +3 位作者 FOSHTOMI Maryam Yazdani NORANIAN Majid MIRA Seyed Sahab JAM Armin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第4期82-88,共7页
The relationship between spatial patterns of macrobenthos community characteristics and environmental conditions(salinity, temperature, dissolved oxygen, organic matter content, sand, silt and clay) was investigated... The relationship between spatial patterns of macrobenthos community characteristics and environmental conditions(salinity, temperature, dissolved oxygen, organic matter content, sand, silt and clay) was investigated throughout the Gorgan Bay in June 2010. Principal components analysis(PCA) based on environmental data separated eastern and western stations. The maximum(4 500 ind./m2) and minimum(411 ind./m2) densities were observed at Stas 1 and 6, respectively. Polychaeta was the major group and Streblospio gynobranchiata was dominant species in the bay. According to Distance Based Linear Models results, macrofaunal total density was correlated with silt percentage and salinity and these two factors explaining 64% of the variability while macrofaunal community structure just correlated with salinity(22% total variation). In general, western part of the bay showed the highest number of species and biodiversity while, the highest density was found at Sta. 1 and in the middle part of the bay. Furthermore, relationship between diversity indices and macrobenthic species with measured factors is also discussed. Our results confirm the effect of salinity as an important factor on distribution of macrobenthic fauna in south Caspian brackish waters. 展开更多
关键词 salinity macrobenthos species-environment relationship Gorgan Bay Caspian Sea
下载PDF
Coordination of economic development and ecological environment in resource exhausted cities
8
作者 FANG Xing-cun CHEN Hao WANG Xiao-ling 《Ecological Economy》 2015年第1期36-42,共7页
This paper establishes the evaluation index system of ecological environment and economic development in resource exhausted cities, and calculates the level of economic development and ecological environment during th... This paper establishes the evaluation index system of ecological environment and economic development in resource exhausted cities, and calculates the level of economic development and ecological environment during the year 2005-2012 by using the entropy method. Furthermore, this study analyzes the coordination degree and coordinated development degree by using the coordination model. The results show that the coordination relationship of economic development and ecological environment continues to improve from 2005 to 2012 in most of these resource exhausted cities. By 2012, other resource depletion cities are in all kinds of hierarchical coordination except Yichun and Hegang. From the standpoint of coordination development degree, although most of these resource exhausted cities have been increased continuously but the level is also lower except in Tongling and Xinyu. Finally, this paper puts forward the corresponding countermeasures and suggestions according to the results of the analysis. 展开更多
关键词 RESOURCES EXHAUSTED CITIES economic development ECOLOGICAL environment COORDINATED relationship
下载PDF
乡村旅游与农村人居环境的耦合协调关系及障碍因子诊断——以山西省为例 被引量:4
9
作者 王冠孝 王伟 张娟娟 《干旱区地理》 CSCD 北大核心 2024年第1期170-180,共11页
在构建乡村旅游与农村人居环境评价指标体系的基础上,运用层次分析法、耦合协调度模型等定量分析山西省11个地级市乡村旅游与农村人居环境的耦合协调关系,运用障碍度模型对其耦合协调关系的障碍因子进行诊断。结果表明:(1)各地级市乡村... 在构建乡村旅游与农村人居环境评价指标体系的基础上,运用层次分析法、耦合协调度模型等定量分析山西省11个地级市乡村旅游与农村人居环境的耦合协调关系,运用障碍度模型对其耦合协调关系的障碍因子进行诊断。结果表明:(1)各地级市乡村旅游水平、农村人居环境水平的区域差距较大,且二者之间存在明显的空间错位。(2)晋中、临汾和运城为中度耦合协调级乡村旅游领先型,晋城、长治和吕梁为中度耦合协调级同步型,太原和阳泉为中度耦合协调级乡村旅游滞后型,忻州和大同为勉强耦合协调级同步型,朔州为初级耦合协调级乡村旅游滞后型。(3)基础设施、公共服务、产业机构是限制山西省乡村旅游与农村人居环境耦合协调发展的关键障碍因子,且7个维度的障碍分布状况差异较大,各地级市的关键障碍因子并不一致。(4)山西省今后应加强基础设施建设、提升公共服务水平和优化乡村旅游供给,并结合各区域的耦合协调关系及障碍因子状况,采取合理措施推动乡村旅游与农村人居环境持续协调发展。 展开更多
关键词 乡村旅游 农村人居环境 耦合协调关系 障碍度 山西省
下载PDF
关中盆地新石器时期水沟遗址人类活动与自然地理环境适宜性研究
10
作者 张俊辉 周雄辉 +9 位作者 辛怡华 王颢 吴博闻 刘鑫 关运玖 张健 王亚欣 张翀 刘滨 康秀丽 《地理科学》 CSSCI CSCD 北大核心 2024年第6期1069-1079,共11页
本研究通过对关中盆地西部新石器时期水沟遗址人类活动的灰坑、文化层、房址、陶窑和陶器等遗迹、遗物做了详细的梳理分析,理解区域古人类活动的特征,系统地开展水沟文化层剖面环境磁学和AMS14C年代学研究,恢复该区全新世以来气候变化... 本研究通过对关中盆地西部新石器时期水沟遗址人类活动的灰坑、文化层、房址、陶窑和陶器等遗迹、遗物做了详细的梳理分析,理解区域古人类活动的特征,系统地开展水沟文化层剖面环境磁学和AMS14C年代学研究,恢复该区全新世以来气候变化和古人类活动历史,结果表明:水沟新石器时期古人类活动时间为全新世中期5 530~4 300 a B.P.的气候适宜期,其文化发展处在寒冷干燥向温暖湿润转换的过渡阶段。在GIS空间分析技术支持下提取影响水沟遗迹分布的海拔、坡度、坡向和距水源距离因子,构建指数模型,分析新石器时期水沟遗址古人类活动的自然地理环境适宜性分布规律,主要集中在海拔900~960 m,坡度小于6°,坡向朝南,距水源距离小于200 m的自然环境条件优越的区域,并进一步探讨了古人类活动对环境变化的响应与适应的过程和机制。 展开更多
关键词 关中盆地西部 新石器时期 水沟遗址 环境适宜性 人地关系
下载PDF
治理环境再造:理解技术化背景下基层政府治理困境的一个视角 被引量:1
11
作者 叶娟丽 宋佳琳 《地方治理研究》 CSSCI 2024年第2期15-25,M0002,共12页
近年来在政府治理过程中技术应用不断深入,其实践效果通常是以一体多面、整体局部差异明显的形式呈现出来的。技术治理的内在变化与政府治理逻辑的根本性变革均引人关注。从中观层面看,技术使政府治理向形式简化、责任共担、监管渗透等... 近年来在政府治理过程中技术应用不断深入,其实践效果通常是以一体多面、整体局部差异明显的形式呈现出来的。技术治理的内在变化与政府治理逻辑的根本性变革均引人关注。从中观层面看,技术使政府治理向形式简化、责任共担、监管渗透等方向转变,并导致超越传统科层制的制度控制、条块权力调整的结构重塑、合法性转移的价值置换等结果。基层政府所处的治理环境由此发生了全面的颠覆与革新,正面临着灵活性受限、自主性下降、正当性模糊等困境。技术改革的积极推进应适当考虑基层政府的技术适配性,通过对一线治理主体赋能来加强和引导技术治理,从而实现持续性基层善治。 展开更多
关键词 政府治理 技术治理 治理环境 科层制 条块关系 合法性
下载PDF
产教集体行动困境与融合:基于组织场域的结构性分析
12
作者 何百通 朱芝洲 李静 《中国职业技术教育》 北大核心 2024年第21期22-30,共9页
产教融合是产业发展的内在规律和现代职业教育高质量发展的必然要求,已成为国家层面的重大战略举措。然而,在实践过程中,产教集体行动困境似乎成为“天然的常态”,这是产教组织场域参与主体、关系系统和制度环境等结构性要素共同作用的... 产教融合是产业发展的内在规律和现代职业教育高质量发展的必然要求,已成为国家层面的重大战略举措。然而,在实践过程中,产教集体行动困境似乎成为“天然的常态”,这是产教组织场域参与主体、关系系统和制度环境等结构性要素共同作用的结果。破解困境之策在于:主体层面,要正视利益诉求,价值共创共享,提供产教集体行动的持续性动力;关系系统层面,要创新组织形态,提升结构化程度,稳固产教集体行动的共生性空间;制度环境层面,要完备制度性要素,刚柔相济,形成产教集体行动的约束性力量。 展开更多
关键词 组织场域 产教融合 集体行动 主体 关系系统 制度环境
下载PDF
东北地区城镇化与资源环境承载力耦合关系的时空变化
13
作者 任婉侠 韩彬 谢潇 《生态经济》 北大核心 2024年第5期79-88,共10页
理清城镇化与资源环境承载力耦合关系可为城市可持续发展转型提供决策参考。在分析2003—2019年东北地区城镇化与资源环境承载力时空格局的基础上,采用耦合协调度模型定量剖析了二者耦合关系的时空变化特征。结果显示:2003—2019年,东... 理清城镇化与资源环境承载力耦合关系可为城市可持续发展转型提供决策参考。在分析2003—2019年东北地区城镇化与资源环境承载力时空格局的基础上,采用耦合协调度模型定量剖析了二者耦合关系的时空变化特征。结果显示:2003—2019年,东北地区综合城镇化水平提升了114.29%,总体呈现“东高西低”、辽中南城市群和哈长城市群核心城市引领全域发展的局面;资源环境承载力呈增加趋势,增幅36.09%,空间上聚集于哈大线周边区域;资源环境承载力水平与综合城镇化水平的耦合协调度总体上呈上升趋势,近年增幅有所下降,且辽西北、吉林南部和黑龙江西北部耦合协调度相对较低,核心城市和重要城市耦合协调度普遍较高。亟须提升核心城市对中小城镇的辐射引领能力,并加强生态退化地区的环境保护和高质量发展。 展开更多
关键词 城镇化 资源环境承载力 耦合关系 时空变化 东北地区
下载PDF
季节性河流生态环境复苏关键问题研究
14
作者 刘晓波 董飞 +4 位作者 王威浩 张剑楠 黄爱平 马冰 司源 《中国水利》 2024年第21期29-36,23,共9页
全球有超过50%的河流为季节性河流,由于气候变化、极端天气与人类活动影响,这一比例仍在上升。2023年,水利部印发《母亲河复苏行动河湖名单(2022—2025年)》,79条河流中有52条为断流河流。较之一般河流,季节性河流干湿交替的水文节律孕... 全球有超过50%的河流为季节性河流,由于气候变化、极端天气与人类活动影响,这一比例仍在上升。2023年,水利部印发《母亲河复苏行动河湖名单(2022—2025年)》,79条河流中有52条为断流河流。较之一般河流,季节性河流干湿交替的水文节律孕育了其特有的生态水文非连续响应关系。长期以来,河流研究的重点多为常年流水河流,而忽视了季节性河流。针对常年流水河流的研究结论不能直接应用于季节性河流。基于大量文献调研,从季节性河流的内涵与基本特征、生态水文响应关系、健康评估、生态流量适应性调控等4个方面,对季节性河流进行总结分析。研究表明:当前季节性河流缺乏统一的定义和内涵,季节性河流自身应有的水文情势、生态系统过程缺乏深入研究,季节性河流指示生物的确定方法不统一,缺少普遍适用的季节性河流生态系统健康评价基准,缺乏针对季节性河流适宜水量阈值的优化调控方法。在季节性河流缺乏基础理论的情况下,厘清季节性河流的基本概念,科学确定其生态水文过程,形成生态系统健康评价基准,探索生态环境复苏的水量阈值优化调控方法,是解决制约季节性河流生态环境复苏关键问题的重要途径,也是亟需研究的重点方向。 展开更多
关键词 季节性河流 生态环境复苏 生态水文过程 生态流量 生态水文响应关系
下载PDF
城市“亲清”政商关系与企业纳税遵从度
15
作者 谢贞发 章蕾 《财经理论与实践》 CSSCI 北大核心 2024年第4期59-67,共9页
利用《中国城市政商关系排行榜》构建的“亲清”政商关系健康指数及其二级、三级构成指标,基于2017—2019年中国沪深A股上市公司的微观样本,实证考察城市“亲清”政商关系对企业纳税遵从度的影响。研究结果表明:健康的城市“亲清”政商... 利用《中国城市政商关系排行榜》构建的“亲清”政商关系健康指数及其二级、三级构成指标,基于2017—2019年中国沪深A股上市公司的微观样本,实证考察城市“亲清”政商关系对企业纳税遵从度的影响。研究结果表明:健康的城市“亲清”政商关系有助于提高企业纳税遵从度,特别是对规模小、盈利水平低、治理水平低、成长性高的企业促进作用更大,在高城市等级地区中的提升相比也更高;“亲清”政商关系建设提升企业纳税遵从度的作用主要来自“亲近”方面,且主要体现在政府对企业的关心和公共服务上。鉴于此,各城市政府应充分重视“亲清”政商关系建设,着重于“亲近”指标的优化,持续增强对企业的关心并提升公共服务水平,营造市场化、公平化、便利化的营商环境,更好地提升企业纳税遵从度。 展开更多
关键词 “亲清”政商关系 营商环境 企业纳税遵从度
下载PDF
新型政商关系促进民营企业高质量发展:理论与实证
16
作者 朱巧玲 雷雨荷 《经济问题》 CSSCI 北大核心 2024年第11期80-90,共11页
构建新型政商关系有利于进一步激发市场活力和更好发挥市场机制作用,对于促进民营企业高质量发展具有重要意义。民营企业高质量发展是我国实现高质量发展的重要基础,是构建高水平社会主义市场经济体制的重要推动力量。以2017—2021年中... 构建新型政商关系有利于进一步激发市场活力和更好发挥市场机制作用,对于促进民营企业高质量发展具有重要意义。民营企业高质量发展是我国实现高质量发展的重要基础,是构建高水平社会主义市场经济体制的重要推动力量。以2017—2021年中国城市政商关系健康指数和民营企业上市公司数据为样本,通过构建双向固定效应模型来考察新型政商关系如何影响民营企业高质量发展。研究结果表明,城市政商关系健康指数提升一个单位,该城市民营企业的全要素生产率则提高11.9%,并且经过一系列稳健性检验后该结果依然成立。从影响机制来看,新型政商关系通过缓解融资约束、鼓励技术创新、提升市场化水平以及激发企业家精神等路径来对民营企业高质量发展产生积极影响。基于此,要促进民营企业高质量发展,首先必须要树立正确的政绩观,着力提高党员干部的市场意识、服务意识,其次加快企业服务体系的构建,最后要完善各部门优化营商环境政策整合机制,强化政策部门和企业之间的协调沟通机制,为促进民营企业高质量发展提供坚实保障。 展开更多
关键词 新型政商关系 企业高质量发展 营商环境 全要素生产率
下载PDF
职住地建成环境对轨道交通通勤行为的非线性影响机制研究——以武汉市为例
17
作者 彭建东 张远航 +2 位作者 申犁帆 代琦 杨红 《地理科学》 CSSCI CSCD 北大核心 2024年第9期1534-1543,共10页
改革开放以来中国大城市快速蔓延导致了职住分离及交通拥堵等问题,倡导轨道交通等绿色交通方式出行成为大城市缓解通勤压力的重要手段。当前研究主要以居住地作为地理背景考察建成环境对轨道交通通勤的作用,但较少探索就业地建成环境的... 改革开放以来中国大城市快速蔓延导致了职住分离及交通拥堵等问题,倡导轨道交通等绿色交通方式出行成为大城市缓解通勤压力的重要手段。当前研究主要以居住地作为地理背景考察建成环境对轨道交通通勤的作用,但较少探索就业地建成环境的影响。本研究以武汉市为例,通过189个轨道站点的刷卡数据识别轨道交通通勤人员并构建通勤出行链,通过梯度提升决策树(GBDT)解析职住地涉及建成环境和轨道站点的30个特征因素对通勤客流量和通勤时间的非线性影响机制。研究发现:①居住地通勤客流量表现为较集中的点状分布,就业地通勤客流量则呈现显著的“中心-外围”结构,职住地两端通勤时间的空间格局均呈中间低、外围高的分布特征;②职住地周边建成环境因素对轨道交通通勤客流量和通勤时间普遍存在非线性影响及阈值效应,整体而言居住地建成环境的相对影响程度高于就业地,但就业地“公司企业数”是影响通勤客流最重要的要素,就业地“与城市中心距离”则是影响通勤时间的首要因素;③职住地周边同一建成环境因素,对于通勤客流量和通勤时间的影响可能截然相反,这与城市轨道交通网络建设和社会实际发展状况相关。研究结果可以更好地理解职住地建成环境与轨道交通通勤行为的关联,有助于促进城市轨道交通和城市职住空间的协调发展。 展开更多
关键词 职住关系 建成环境 城市轨道交通 通勤行为 梯度提升决策树 武汉市
下载PDF
AGI时代人机共生景观下的媒介化生存:新的延伸、相互形塑与潜在异化
18
作者 张静 王楠 《新媒体与社会》 2024年第2期223-233,M0014,M0015,共13页
随着Sora的横空出世,人类在某种意义上探索出了AGI时代的入口。当前人类社会已进入深度媒介化阶段,人机协同共生是实现价值最大化的必然路径。本文以媒介环境学派为线索,考察了媒介变迁史与社会结构演变的联系,并从中推演人工智能接入... 随着Sora的横空出世,人类在某种意义上探索出了AGI时代的入口。当前人类社会已进入深度媒介化阶段,人机协同共生是实现价值最大化的必然路径。本文以媒介环境学派为线索,考察了媒介变迁史与社会结构演变的联系,并从中推演人工智能接入媒介后可能对社会产生的作用。在人机共生景观中,人的媒介化生存需要沿着三重视角展开:一是人与媒介之间超越中介的全新延伸,二是人与媒介彼此塑造共生的复合关系,三是警惕人工智能对人的反向异化。 展开更多
关键词 媒介化生存 AGI 人机关系 媒介环境 SORA
下载PDF
明清兽灾言说与生态保护意识
19
作者 王立 《宝鸡文理学院学报(社会科学版)》 2024年第1期100-106,共7页
明清战乱与人口增长,边荒垦殖扩大,侵犯了野生动物领地,加剧了兽灾爆发。人们杀兽自救,民间叙事者标举捕猛兽器械和捕兽技术。站在人类中心立场上,把野兽完全推到灾害施加者的被告席上。面临野兽袭击,人与家畜亲密依存关系强化,人往往... 明清战乱与人口增长,边荒垦殖扩大,侵犯了野生动物领地,加剧了兽灾爆发。人们杀兽自救,民间叙事者标举捕猛兽器械和捕兽技术。站在人类中心立场上,把野兽完全推到灾害施加者的被告席上。面临野兽袭击,人与家畜亲密依存关系强化,人往往依靠与家畜互助互卫,家畜形象被愈加伦理化。人们还依靠地方官员德行、能力弭灾驱灾;许多边荒地区则以祷神、责神来治理兽灾。对猛兽威胁,明清还多取人兽亲和的神幻想象。地方官也更为积极地表彰资助协力抗灾的百姓。在华夏灾害、御灾与生态学融合的文学书写中,是人与动物关系的一个令人警醒的方面。 展开更多
关键词 野生动物 兽灾 自然环境 御灾书写 生态与灾害关系
下载PDF
基于XGBOOST-SHAP的地铁建成环境与站点出行距离的非线性关系研究 被引量:4
20
作者 李培坤 陈旭梅 +3 位作者 鲁文博 马嘉欣 刘屹 王昊 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第4期1624-1633,共10页
相较于传统地铁客流量特征分析,地铁站点平均出行距离的研究可以更加精细化了解地铁网络客流流动性特征。为探究多重建成环境与站点平均出行距离之间的复杂关系,以西安市地铁系统为研究对象,从土地利用、兴趣点分布、周边交通建成环境... 相较于传统地铁客流量特征分析,地铁站点平均出行距离的研究可以更加精细化了解地铁网络客流流动性特征。为探究多重建成环境与站点平均出行距离之间的复杂关系,以西安市地铁系统为研究对象,从土地利用、兴趣点分布、周边交通建成环境、站点自身属性等方面构建11种建成环境指标,建立基于极端梯度提升的XGBOOST-SHAP归因分析架构的可解释性机器学习模型,以揭示两者之间的非线性关系。同时,将该模型拟合回归效果与梯度提升决策树(GBDT)及最小二乘回归(OLS)进行比较,以验证XGBOOST模型在拟合回归效果上的优势。结果表明:XGBOOST模型的R方、平均绝对误差(MAE)、均方误差(MSE)值分别为0.75、0.95、1.36,其拟合效果要优于GBDT与OLS模型。站点平均出行距离呈现出明显的环状分布的空间异质性。SHAP归因分析结果表明:距市中心距离特征贡献最大,路网密度、土地利用混合度、公交线路数量以及住宅数量对出行距离的贡献度也相对较高;POI香农熵指数、餐饮服务点对平均出行距离的正负反馈不明显;其余指标对平均出行距离的影响均呈现出正负反馈机制结合的趋势。研究结果对交通需求分析、线路容量优化、运营效果评估等提供了数据支撑,可有效提高地铁交通便利性,满足不同区域的出行需求并改善整个地铁系统的效率和可持续性。 展开更多
关键词 地铁站点 建成环境 出行距离 XGBOOST模型 SHAP归因分析 非线性关系
下载PDF
上一页 1 2 50 下一页 到第
使用帮助 返回顶部