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Study on Eco-climate Type Regionalization of Wheat Growing Areas in Yunnan Province
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作者 Yongxin LU Limin CAO +1 位作者 Zhongping ZHANG Hongbo LI 《Asian Agricultural Research》 2013年第7期38-40,45,共4页
In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptabil... In order to provide an objective and scientific theoretical basis for rational distribution of wheat growth in Yunnan Province,according to the relationship between Yunnan weather conditions and wheat growth adaptability,a study on eco-climate type regionalization of wheat growing areas in Yunnan was conducted using principal component analysis and GIS technology. The results show that Yunnan Province could be divided into four types,namely southern warm and humid wheat growing area,central semi-arid wheat growing area,central semi-humid wheat growing area and north-central cold wheat growing area. 展开更多
关键词 WHEAT GROWING areas Principal COMPONENT ANALYSIS E
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A comparative study of the land-atmosphere energy and water exchanges over the Tibetan Plateau and the Yangtze River Region
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作者 Nan Yao Yaoming Ma +3 位作者 Binbin Wang Jun Zou Jianning Sun Zhipeng Xie 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第2期52-59,共8页
正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8... 正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气,气候变化的关键.为了研究属于干旱/半干旱气候的青藏高原(TP)和湿润/半湿润气候的长江流域(YRR)之间地表能量和水分交换的异同,本文对比分析了两个区域8个不同地表类型(包括高山荒漠,高山草地,(平原)城市和(平原)草地等)观测站点的地表辐射和能量通量数据.结果显示:(1)TP由于高原大气层稀薄且空气洁净,年平均入射短波辐射为251.3W m^(-2),是YRR的1.7倍.加之高原地表反照率高导致反射辐射(59.6 W m^(-2))是YRR的2.87倍.入射及出射的长波辐射为231.5和338.0 W m^(-2),分别为YRR的0.64和0.83.而两个区域的净辐射差异不大;(2)草地站更多的潜热释放使得地表总加热效率高于城市和高山荒漠,TP和YRR的草地站的年平均潜热分别为35.0和38.8 W m^(-2),而植被稀疏且土壤干燥的高山荒漠地区感热最大,年平均感热为42.1 W m^(-2);其次是城市下垫面,其年平均感热为37.7 W m^(-2).研究结果揭示了不同气候背景下典型下垫面地气相互作用特征,为地气相互作用过程深入分析奠定了基础. 展开更多
关键词 能量和水分交换 辐射分量 地表能量通量 青藏高原 长江流域 不同地表类型
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Research on Types of Regional Eco-protection Space and Its Protection Countermeasures——A Case Study of Chongzuo City of Guangxi Province in China
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作者 周兴 陈务开 《Journal of Landscape Research》 2012年第2期41-44,共4页
Reasonable division of eco-protection space is a vital measure to coordinate the relationship between regional economic development and ecological protection,and to realize regional sustainable development.The paper h... Reasonable division of eco-protection space is a vital measure to coordinate the relationship between regional economic development and ecological protection,and to realize regional sustainable development.The paper has concluded the concept of regional eco-protection space which has been divided into ecological space of forbidding development and restricted development.It has discussed methods to divide regional eco-protection space and proposed protection countermeasures for regional eco-protection space.GIS has been adopted to divide eco-protection space of Chongzuo City.The eco-protection space of Chongzuo City covers an overall area of 5,833.94 km2,taking up 34.04% of the total area of Chongzuo City;ecological space of forbidding development covers an area of 1,555.35 km2,taking up 8.97%;the ecological space of restricted development covers an area of 4,344.59 km2,taking up 25.07%.Finally,the protection countermeasures for regional eco-protection space have been proposed. 展开更多
关键词 regional eco-protection SPACE type PROTECTION COUNTERMEASURES
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Spatial Pattern and Regional Types of Rural Settlements in Xuzhou City,Jiangsu Province,China 被引量:7
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作者 MA Xiaodong QIU Fangdao +2 位作者 LI Quanlin SHAN Yongbin CAO Yong 《Chinese Geographical Science》 SCIE CSCD 2013年第4期482-491,共10页
This paper principally focuses on the morphological differences,spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China.Using satellite images of Xuzhou City taken in 2007 a... This paper principally focuses on the morphological differences,spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China.Using satellite images of Xuzhou City taken in 2007 and 2008 and models of exploratory spatial data analysis(ESDA) and spatial metrics,the paper conducts a quantitative analysis of the morphological pattern of rural settlements,and finds significant characteristics.First,rural settlements in Xuzhou City are significantly agglomerated in terms of their spatial distribution;meanwhile,there is significant variation in the geographical density distribution.Second,the scale of rural settlements in Xuzhou City is larger than the average in Jiangsu Province,and the histogram of the scale data is more even and more like a gamma distribution.There are a significant high-value cluster in the scale distribution,and local negative correlation between the scale and density distribution of rural settlements in Xuzhou City.Third,the morphology of rural settlements in Xuzhou City shows relative regularity with good connection and integrity,but the spatial variation of the morphology is anisotropic.Finally,according to the characteristics of density,scale,and form of rural settlements,the rural settlements of Xuzhou City are divided into three types:A high-density and point-scattered type,a low-density and cluster-like type and a mass-like and sparse type.The research findings could be used as the scientific foundation for rural planning and community rebuilding,particularly in less-developed areas. 展开更多
关键词 rural settlements spatial pattern regional types exploratory spatial data analysis(ESDA) Xuzhou City
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Regional Economic Types and Development Strategy of Small Towns in Suburb Beijing
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作者 Han Fei Cai Jianming Liu Junping 《Chinese Journal of Population,Resources and Environment》 2010年第2期75-82,共8页
The purpose of this article is to classify the regional economic types and development dynamics of small towns in suburb Beijing by applying the classification methods developed by Nelson's method and Location Quo... The purpose of this article is to classify the regional economic types and development dynamics of small towns in suburb Beijing by applying the classification methods developed by Nelson's method and Location Quotient method into 183 small towns in Beijing.Four types of small towns are thus identified,including urban agriculture dominated towns,manufacturing dominated towns,service industry dominated towns and comprehensive type towns with balanced economic development.Within the environment of geographical information system,the spatial distribution pattern of four types of small towns with their evolution trend is analyzed.The results indicate that four types of small towns have obvious'core-periphery'spatial structure but with different functional orientations and evolution mechanisms.Based on this,the different development strategies for each type of small towns are summarized,providing a scientific reference for the differentiating planning and development strategies of these small towns. 展开更多
关键词 SUBURBS small towns regional economic types development strategy BEIJING
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Geochemical Features of a Subduction Initiation Ophiolite Type in Habana-Matanzas Region(Western Cuba)
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作者 Angélica Isabel LLANES CASTRO Joaquín Antonio PROENZA FERNáNDEZ Esther María CRUZ GáMEZ 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期18-,共1页
We present new geochemical data for the upper mantle and crustal sections(whole-rock major and trace element compositions)as well as mineral chemical data,from the Northern Carbibbean ophiolites in the Habana-Matanzas... We present new geochemical data for the upper mantle and crustal sections(whole-rock major and trace element compositions)as well as mineral chemical data,from the Northern Carbibbean ophiolites in the Habana-Matanzas region in Western Cuba.These ophiolites are part of the Northern Cuban Ophiolitic Belt(NCOB),extending for more than 1000 km along the island.The upper mantle peridotites are composed mainly of refractory harzburgite with tectonite textures,and show convex-downward patterns depleted in MREE normalized to chondrite values(Mc Donough and Sun,1995).These geochemical trends are characteristic for depleted mantle wedge peridotites metasomatized by slab-derived,LREE enriched melts.The NCOB also includes abyssal peridotites having lower LREE/HREEratiosanddisplayingrelativelyhomogeneous and flat patterns from MREE to HREE.These peridotites represent fragments accreted into the continental margin from a subducted oceanic lithosphere.Gabbro and dolerite units in the NCOB are systematically depleted in High Field Strength Elements(HFSE:Nb,Ta,Hf,Ti)and REE with respect to N-MORB(<1 X N-MORB).Their melt evolution was affected by subduction input.Spatially associated granitic rocks have a volcanic arc geochemical affinity.Some mafic extrusive rocks within the NCOB exhibit boninitic signatures,and may represent the products of subduction initiation magmatism,whereas other extrusive rock occurrences display N-MORB to E-MORB geochemical fingerprints,slightly modified by subduction derived fluids.Using these geochemical data and constraints,we present a tectonomagmatic model for the evolution of the NCOB within the framework of the Caribbean geology. 展开更多
关键词 Western Cuba rock Geochemical Features of a Subduction Initiation Ophiolite type in Habana-Matanzas region
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Polymorphism in the upstream regulatory region of human papilloma virus type 16 from the cervical cancer biopsies in Xinjiang Uygur women 被引量:4
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作者 MENG YU ZHENG HAI MA YAN PIN WANG XI DAN RE FU CHUN ZHANG 《Journal of Microbiology and Immunology》 2006年第3期182-188,共7页
To investigate the mutations in the upstream regulatory region (URR) of human papillomavirus type 16 (HPV-16) from the cervical cancer biopsies in Xinjiang Uygur women and its relationship to the high incidence of cer... To investigate the mutations in the upstream regulatory region (URR) of human papillomavirus type 16 (HPV-16) from the cervical cancer biopsies in Xinjiang Uygur women and its relationship to the high incidence of cervical cancer in the southern Xinjiang, the tissue DNA was extracted from the cervical cancer biopsies, and the URR segment of HPV-16 DNA was amplified, sequenced and analyzed. Thereafter, the polymorphism of URR in HPV-16 was then analyzed. It was demonstrated that the positive rate detected for the presence of URR in HPV-16 was 89.47% (17/19). Compared with the previously published sequence in URR of prototype HPV-16, some mutations were detected in the sequence of URR. The mutations in 17 URR fragments of HPV-16 could be divided into 11 patterns (XJU-1 to XJU-11) at nucleic acid level, in which each of XJU-1 and XJU-4 accounted for 23.53% (4/17), and other patterns of mutation accounted for 5.88% (1/17) . In comparison with the URR of prototype HPV-16, the DNA identity of these patterns was 98.50%-99.68% . In these 17 URR fragments, two point mutations occurred at position 7192 (G to T) and position 7520 (G to A) and they appeared to be constant in Xinjiang area. These two mutations were ubiquitous in the Asia-American type and conferred strong infection activity and carcinogenicity of this virus. In addition, the mutations at position 7729 (A to C), position 7843 (A to G) and position 7792 (C to T) could enhance its transcription activity considerably. It is concluded that some mutations occur in URR gene of HPV-16 in the cervical cancer biopsies taken from Uygur women in Xinjiang area, suggesting that certain relationship exists among the mutations in URR of HPV-16, the phylogeny of HPV-16 and the high incidence of cervical cancer in southern part of Xinjiang area. 展开更多
关键词 Human papillomavirus type 16 Cervical carcinoma Upstream regulatory region Polymorphism
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The Type and Evolution of Neoproterozoic Sedimentary Basin in the Dahongshan Region,Northern Margin of the Yangtze Block:An Insight from Sedimentary Characteristics of the Huashan Group 被引量:3
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作者 DENG Qi WANG Jian +3 位作者 CUI Xiaozhuang WANG Zhengjiang SHI Meifeng MA Long 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第5期1917-1918,共2页
Objective The Huashan group(composed of the lower Hongshansi Formation and the upper Liufangzui Formation)is an important Neoproterozoic stratigraphic unit along the northern margin of the Yangtze Block.Previous doc... Objective The Huashan group(composed of the lower Hongshansi Formation and the upper Liufangzui Formation)is an important Neoproterozoic stratigraphic unit along the northern margin of the Yangtze Block.Previous documents have focused on the geochronological and geochemical aspects of the Neoproterozoic sedimentary basin in the Dahongshan region.However. 展开更多
关键词 The type and Evolution of Neoproterozoic Sedimentary Basin in the Dahongshan region Northern Margin of the Yangtze Block
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REGIONAL DIFFERENTIATION OF CRITICAL CONCENTRATION OF ARSENIC(As) AND CADMIUM (Cd) IN MAIN SOIL TYPES OF CHINA
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作者 Luo Jinfa Xia Zenglu(Institute of Geography, CAS, Beijing 100101People’s Republic of China ) 《Journal of Geographical Sciences》 SCIE CSCD 1996年第2期60-65,共6页
Studies of critical concentration distribution features of polluted elements of Cd and As in main soil types of China, such as laterite, crimson soil, purplish soil, yellow brown soil, brunisolic soil, black soil, cin... Studies of critical concentration distribution features of polluted elements of Cd and As in main soil types of China, such as laterite, crimson soil, purplish soil, yellow brown soil, brunisolic soil, black soil, cinnamon soil and sierozem revealed that soil types vary in different zones, so do their critical concentrations.The critical concentration has a zonal differentiation with the distribution of soil types from south to north, and from east to west. The critical concentration of Cd increases from south to north (yellow brown soil,brunisolic soil and cinnamon soil),and from east to west (black soil and sierozem). This coincides With changes of climate zones and soil zones. On the contrary, the critical concentration of Asdecreases from south to north and from east to west. 展开更多
关键词 soil types critical level AS CD regional differentiation
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An Empirical Analysis of Regional Disparity of Financial Exclusion Based on Types and Levels of Financial Institution
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作者 Yongbin LU Xianping ZHOU +1 位作者 Min LI Wanpeng ZOU 《Asian Agricultural Research》 2015年第11期38-46,共9页
We make an empirical analysis of regional characteristics of influence factors of financial exclusion by using the data of types and levels of financial institutions in China from 1998 to 2012. The study shows that th... We make an empirical analysis of regional characteristics of influence factors of financial exclusion by using the data of types and levels of financial institutions in China from 1998 to 2012. The study shows that the number of financial institutions continues to increase,but with uneven distribution; the density of financial institutions increases steadily and the gap between the eastern regions and the Midwest is huge; the commercial banks of the eastern regions account for the highest proportion but the rate of basic outlets of the commercial bank is low,the rate of basic outlets of the rural institution bank is relatively higher,and the proportion of the Midwest rural banks is high. Even though the financial exclusion eases,large differences still exist in different areas and the situation is rather critical in rural areas,especially the financial exclusion in western rural areas is the worst. The economic development level,area scale,government expenditure,personal savings level,per capita consumption and educational level have different effects on financial exclusion. Accordingly,this paper puts forward the recommendations for coordinating the financial resource from all regions and reducing the regional financial exclusion. 展开更多
关键词 FINANCIAL EXCLUSION typeS and LEVELS of FINANCIAL institutions regional DISPARITY
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gastrointestinal symptom prevalence depends on disease duration and gastrointestinal region in type 2 diabetes mellitus 被引量:5
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作者 Midori Fujishiro Akifumi Kushiyama +7 位作者 Hiroki Yamazaki Sunao Kaneko Yuko Koketsu Takeshi Yamamotoya Takako Kikuchi Hideyuki Sakoda Ryo Suzuki Takashi Kadowaki 《World Journal of Gastroenterology》 SCIE CAS 2017年第36期6694-6704,共11页
AIM To unravel relationships between gastrointestinal(GI)symptoms impairing quality of life(QOL)and clinical profiles of diabetes mellitus(DM)patients. METHODS We enrolled 134 outpatients with type 2 DM.Mean age was 6... AIM To unravel relationships between gastrointestinal(GI)symptoms impairing quality of life(QOL)and clinical profiles of diabetes mellitus(DM)patients. METHODS We enrolled 134 outpatients with type 2 DM.Mean age was 64.7 years,mean body mass index was 24.7 RESULTS Lower abdominal symptoms were found to be more frequent than those affecting the upper abdomen.Diabetic duration and medications showed associations with GI symptoms.We identified differences in peak prevalences of the five symptoms.Gastralgia(P=0.02vs 10-14 years)and total GI symptoms(P=0.01 and P=0.02 vs 5-9 years and 10-14 years,respectively)peaked at a diabetes duration of 15-19 years.Heartburn(P=0.004)and postprandial fullness(P=0.03)tended to increase with disease duration.Constipation and diarrhea showed bimodal peaks,with the first early and the second late(e.g.,P=0.03 at 15-19 years vs 10-14years for diarrhea)in the disease course.Finally,GI symptoms showed clustering that reflected the region of the GI tract affected,i.e.,constipation and diarrhea had similar frequencies(P<0.0001). CONCLUSION Our study highlights the importance of questioning patients about QOL impairment due to abdominal symptoms,especially in the early and the late periods of diabetes. 展开更多
关键词 GASTROINTESTINAL SYMPTOMS QUESTIONNAIRE survey Disease DURATION type 2 diabetes Quality of life GASTROINTESTINAL TRACT regionS
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湖湘古代中医药文献的类型与特点述略 被引量:1
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作者 许盈 葛金文 《湖南中医药大学学报》 CAS 2024年第1期158-162,共5页
湖湘中医药文献既是湖湘先人认识疾病的重要途径,又是湖湘地区中医药知识的重要宝库。从早期的口头传承到简帛、竹木简牍,再到纸质文献,湖湘中医药文献呈现了丰富多样的类型和独特的发展轨迹。周秦两汉时期,湖湘中医药文献开始萌芽,主... 湖湘中医药文献既是湖湘先人认识疾病的重要途径,又是湖湘地区中医药知识的重要宝库。从早期的口头传承到简帛、竹木简牍,再到纸质文献,湖湘中医药文献呈现了丰富多样的类型和独特的发展轨迹。周秦两汉时期,湖湘中医药文献开始萌芽,主要以简帛文献为主;魏晋隋唐时期,文献载体逐渐向竹木简牍转变,且养生文献得到发展;宋金元时期,方书集合文献占据主导地位,中医药知识体系更趋完善;明清时期,见证了湖湘中医药文献的鼎盛,特别是处理时疫的文献得到广泛流传。通过厘清湖湘古代中医药文献的类型与特点,展示和挖掘湖湘中医药知识和理论的构建历程,从而促进湖湘中医药及其文献的研究利用。 展开更多
关键词 湖湘文化 中医药文献 文献载体 文献类型 地域医学特色
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江西省57个淘宝村的发育水平差异及影响因素
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作者 王芳 李晗 丁志伟 《湖北农业科学》 2024年第8期281-288,302,共9页
运用熵权-TOPSIS法和空间分析技术评价淘宝村发育水平的时空特征并解释其影响因素。结果表明,从空间发育等级上看,总体呈赣北、赣南地区发展优于赣中地区的特征,发育水平高值区和低值区在赣南地区“交错式发展”,中等水平区广泛分布,呈... 运用熵权-TOPSIS法和空间分析技术评价淘宝村发育水平的时空特征并解释其影响因素。结果表明,从空间发育等级上看,总体呈赣北、赣南地区发展优于赣中地区的特征,发育水平高值区和低值区在赣南地区“交错式发展”,中等水平区广泛分布,呈以南昌市和赣州市为核心向四周辐射式发展的格局;从时间上看,缓慢起步阶段(2013—2016年)以红星村为起点扩散形成4个淘宝村,平稳增长阶段(2017—2018年)以每年4个淘宝村的增量稳步提升,快速蔓延阶段(2019—2021年)裂变式增至57个淘宝村;淘宝村数量和发育水平的核密度空间分布上虽然均呈现出“整体少量零散、局部相对集中”的不均衡现象,但在赣北形成了三角形高密度值区;淘宝村空间扩散的初期阶段以“点状”独立式发展为主,扩散中期依托专业带动,以点为核心向四周“以点带线”式发展,到了扩散后期主要以共同发展和政府扶植为主,进行“以线织网”式交织扩散;从影响因子看,淘宝村的发育是多种因素综合作用的结果,经济基础、交通水平和平台支撑是主要影响因素,服务水平、互联网水平和信息通讯对淘宝村的发育有正向影响。 展开更多
关键词 淘宝村 发育水平 时空特征 扩散类型 地域模式 影响因素
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土地利用方式对豫西丘陵区土壤团聚体稳定性及其化学计量特征的影响 被引量:1
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作者 郭大勇 刘海燕 +6 位作者 杜鹃 曾祥 王翔宇 周子琪 刘雪涛 寇太记 陈鲜妮 《河南科技大学学报(自然科学版)》 CAS 北大核心 2024年第3期88-95,共8页
为探究不同土地利用方式对土壤团聚体组成和碳、氮、磷化学计量特征的影响,以豫西丘陵区相同冲积母质土壤为研究对象,对果园、林地、草地和农田等4种土地利用方式的土壤团聚体稳定性、碳含量、氮含量、磷含量及化学计量特征进行了测定... 为探究不同土地利用方式对土壤团聚体组成和碳、氮、磷化学计量特征的影响,以豫西丘陵区相同冲积母质土壤为研究对象,对果园、林地、草地和农田等4种土地利用方式的土壤团聚体稳定性、碳含量、氮含量、磷含量及化学计量特征进行了测定分析。结果表明:4种土地利用方式土壤均表现出以0.25~2 mm粒级为优势团聚体分布的特征,以农田土壤最高,质量分数为58.49%~66.11%,土壤团聚体稳定性农田>林地>草地和果园。全碳含量(以质量比表示)随团聚体粒级的下降呈现减少趋势,果园在4个粒级上的全碳含量均显著地高于其他3种土地利用方式,在<2 mm的2个粒级上4种土地利用方式的全碳含量均表现为果园>农田>林地>草地。果园C/N和C/P均显著地高于林地、草地和农田,林地在<2 mm的3个土壤团聚体粒级上的C/N均显著低于草地和农田,但在<2 mm土壤团聚体粒级上的C/P和N/P均显著高于草地。土地利用方式对土壤团聚体稳定性和化学计量特征有显著影响。豫西丘陵区的农田团聚体稳定度最高,果园显示出高的有机输入特征,林地主要受磷限制,草地主要受氮限制。 展开更多
关键词 土地利用方式 土壤团聚体 化学计量学 丘陵区
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滇中主要森林类型土壤团聚体稳定性及其变化机制
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作者 王平 丁智强 +1 位作者 李璐杉 李玉辉 《水土保持研究》 CSCD 北大核心 2024年第5期232-242,共11页
[目的]团聚体稳定性是评估退化生态系统植被恢复后土壤质量变化的重要指标,研究滇中地区主要森林类型土壤团聚体稳定性差异及其变化机制,为该地未来植被恢复、改造过程中的树种选择、森林资源管理提供科学支撑。[方法]选择云南松林(PY)... [目的]团聚体稳定性是评估退化生态系统植被恢复后土壤质量变化的重要指标,研究滇中地区主要森林类型土壤团聚体稳定性差异及其变化机制,为该地未来植被恢复、改造过程中的树种选择、森林资源管理提供科学支撑。[方法]选择云南松林(PY)、华山松林(PA)、银荆林(AD)、旱冬瓜林(ACF)、针阔混交林(TF)、次生常绿阔叶林(SF)6种主要森林类型作为研究对象,以坡旱地(DSL)作为对照,采集0—20 cm,20—40 cm和40—60 cm土样,利用干、湿筛分法分离测定>5 mm,5~2 mm,2~0.25 mm,<0.25 mm 4个粒级团聚体含量,计算水稳性大团聚体含量(WR_(>0.25))、平均重量直径(MWD)、几何平均直径(GMD)和结构破坏率(PAD)4个稳定性指标,对土壤团聚体稳定性进行研究。[结果](1) 6种森林类型在0—60 cm均以0.25~2 mm的小团聚体为主,而坡旱地随着土层深度的增加,粒级从0.25~2 mm向<0.25 mm转变;(2) 0—60 cm土层中坡旱地平均WR_(>0.25),MWD,GMD和PAD分别为55.40%,1.16 mm,0.52 mm,40.47%,6种森林类型分别为71.61%~78.20%,1.97~2.61 mm,0.93~1.27 mm,12.59%~20.47%,团聚体稳定性总体表现为坡旱地最差,次生常绿阔叶林、针阔混交林最好,其次是云南松林、旱冬瓜林,银荆林和华山松林较差;(3)团聚体稳定性在宏观尺度上受森林类型、土层深度及其交互作用的显著影响(p<0.001),而在微观尺度上主要受土壤容重、非毛管孔隙度、全钾、有机质、砂粒和黏粒含量的显著影响(p<0.05),土壤理化性质、养分、质地解释了团聚体稳定性的90.5%,其中以理化性质、养分及其交互作用的贡献最大,解释率为61.3%,土壤质地往往与其他因子共同影响团聚体稳定性,其独立解释率仅为5.1%。[结论]滇中地区退耕还林可显著提高土壤团聚体稳定性,未来的生态恢复应该以营造云南松林和旱冬瓜林为主,同时避免高强度的人类活动,改善土壤理化性质和增加土壤养分积累,促进人工纯林向针阔混交林及常绿阔叶林演化。 展开更多
关键词 土壤团聚体 稳定性 影响因素 森林类型 滇中地区
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宁南黄土区不同人工植被类型深层土壤水分亏缺评价
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作者 王月玲 许浩 +4 位作者 安钰 万海霞 董立国 韩新生 袁心 《甘肃农业大学学报》 CAS CSCD 北大核心 2024年第2期215-223,共9页
【目的】开展评估不同人工植被类型深层土壤水分亏缺程度,能为区域科学合理实施植被恢复策略提供理论依据。【方法】以宁夏彭阳中庄小流域5种不同植被类型(山桃林、沙棘林、柠条林、苜蓿地,农田为对照)为研究对象,采用土壤水分相对亏缺... 【目的】开展评估不同人工植被类型深层土壤水分亏缺程度,能为区域科学合理实施植被恢复策略提供理论依据。【方法】以宁夏彭阳中庄小流域5种不同植被类型(山桃林、沙棘林、柠条林、苜蓿地,农田为对照)为研究对象,采用土壤水分相对亏缺指数(CSWDI)和干燥化指数(SDI)定量评价模型,对不同植被类型下0~1 000 cm土壤水分亏缺及干燥化程度进行定量化分析与评价。【结果】不同植被类型深层土壤水分变化特征差异明显,0~1 000 cm平均土壤水分含量呈现出农地(16.29%)>山桃林(13.06%)>沙棘林(12.22%)>柠条林(9.12%)>苜蓿地(8.08%)。在垂直剖面上,土壤水分随土层深度增加总体呈现先减小后增加再逐渐稳定的趋势。在0~1 000 cm农地基本没有水分亏缺和干层发生,山桃林、柠条林、沙棘林和苜蓿地均呈现不同程度的土壤水分亏缺现象,平均土壤水分相对亏缺指数分别为0、0.22、0.62、0.35、0.79,平均土壤干燥化指数分别为185.5%、67.45%、51.55%、87.35%、36.10%,5种植被类型中苜蓿地土壤水分亏缺最严重,其次为柠条林、沙棘林、山桃林、农地。山桃林、柠条林、沙棘林、苜蓿地均有不同程度的干层分布,分别呈现中度、轻度和严重干燥化,干层厚度(DSLT)分别为890、860、800、920 cm,DSL-SWC分别为12.42%、8.14%、11.56%、7.76%。【结论】宁南黄土区不同人工植被类型对深层土壤水分亏缺具有明显影响,导致不同程度土壤干层发生,其中苜蓿地土壤水分亏缺最严重,应采取相应措施恢复土壤水分,促进区域水土资源可持续利用和生态健康发展。 展开更多
关键词 植被类型 土壤水分 水分亏缺 宁南黄土区
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中国新型基础设施建设:统计测度及产业结构升级效应 被引量:3
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作者 李旭辉 王经伟 夏万军 《统计学报》 2024年第1期37-47,共11页
系统梳理新基建的主要领域,重塑新基建的测度指标体系,在考察2017—2021年中国新基建水平及特征的基础上,探讨新基建对产业结构升级的影响。研究发现:党的十九大以来,中国新基建水平实现跨越式提升,有效提振了国内需求并推动了数字化转... 系统梳理新基建的主要领域,重塑新基建的测度指标体系,在考察2017—2021年中国新基建水平及特征的基础上,探讨新基建对产业结构升级的影响。研究发现:党的十九大以来,中国新基建水平实现跨越式提升,有效提振了国内需求并推动了数字化转型工作;目前融合基础设施、创新基础设施是部署新基建的主要堵点和难点;随着区域协调发展战略的贯彻落实,近年来新基建的地区差距有所缓解,在区域一体化水平日益提高的基础上应进一步加强区域间的协同联动;新基建可显著促进产业结构升级,且考察期内随时间推移这种正向促进效应愈加明显。 展开更多
关键词 新型基础设施建设 技术创新 数字化转型 区域差距 产业结构升级
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秦岭羽枝青藓生长的关键影响因子
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作者 王春 莫秋霞 +5 位作者 王鹤鸣 陈祥舟 牟泽锴 鞠孟辰 谢永生 卜崇峰 《生态学报》 CAS CSCD 北大核心 2024年第14期6195-6207,共13页
利用苔藓植物开展裸岩工程创面生态修复是一条低成本、高效益的潜在新途径,巨量苔藓种源的供给是实现这种新措施工程化应用的根本前提,而掌握特定藓种生长的发育特征及关键影响因子则是实现这一目标的首要任务。以秦岭地区石生优势藓种... 利用苔藓植物开展裸岩工程创面生态修复是一条低成本、高效益的潜在新途径,巨量苔藓种源的供给是实现这种新措施工程化应用的根本前提,而掌握特定藓种生长的发育特征及关键影响因子则是实现这一目标的首要任务。以秦岭地区石生优势藓种——羽枝青藓(Brachythecium plumosum)为研究对象,利用野外原位观测、室内组织培养及养分施加试验,通过观测生长指标(主茎长、覆盖面积、分枝长和分枝数)和形态变化,了解其自然发育特征和不同繁殖体类型及养分供给模式对其生长发育的影响。结果表明:(1)羽枝青藓通过特有的形态特征适应岩石表层环境。主茎生长时,其侧边分枝同步发育、且表现的较为密集。(2)微生境显著影响羽枝青藓发育。与冠层间相比,冠层下除光照强度降低幅度较大外(15%—55%),空气湿度、温度的变化幅度较小,但羽枝青藓的生长速率提高3倍以上。(3)羽枝青藓的茎和叶片都有发育为配子体的潜力,但茎的再生能力优于叶片,且二者的发育模式不同。接种茎的成活率达到100%,配子体由茎直接再生,发育的原丝体未分化,主要发挥定殖和养分吸收的作用;叶片的成活率仅3.3%,发育过程中先产生原丝体,再分化为配子体。(4)长期营养液供给可能对岩石表层的苔藓生长产生负面影响。Hoagland营养液在试验前期促进了羽枝青藓生长,但也加剧了致病菌和藻类发育,导致后期羽枝青藓发黄枯萎。总的来看:羽枝青藓对逆境有较强的适应性,对微环境变化敏感,周围生长条件适宜时可快速向外扩张。不同的繁殖体和营养液供给模式都会对羽枝青藓的生长产生显著影响。开展羽枝青藓种源扩繁生产时应充分借鉴这些研究结果。 展开更多
关键词 秦岭地区 羽枝青藓 微环境 繁殖体类型 养分供给
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要素禀赋改善、产业结构优化与特殊类型地区共同富裕 被引量:4
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作者 郑瑞强 赖文欢 陈洋庚 《江苏大学学报(社会科学版)》 CSSCI 2024年第1期47-61,共15页
特殊类型地区是推进高质量发展的重点区域,建构“以要素禀赋改善为支撑,产业结构转型升级为引擎,协同驱动区域共同富裕”的逻辑框架,计量分析要素禀赋和产业结构耦合协调度,实证检验三者之间互动关联并探讨其理论蕴含,有益于加快构建支... 特殊类型地区是推进高质量发展的重点区域,建构“以要素禀赋改善为支撑,产业结构转型升级为引擎,协同驱动区域共同富裕”的逻辑框架,计量分析要素禀赋和产业结构耦合协调度,实证检验三者之间互动关联并探讨其理论蕴含,有益于加快构建支持特殊类型地区振兴发展的政策体系和长效机制。结果表明,产业结构调整在要素禀赋影响特殊类型地区振兴发展的过程中发挥中介作用;实现要素禀赋与产业结构的耦合协调可以更好推进区域共同富裕,二者耦合协调程度在要素禀赋促进区域共同富裕过程中发挥门槛效应;要素禀赋及其与产业结构耦合协调度发挥正向作用时,其滞后一期变量对促进区域共同富裕具有阻滞作用。据此针对要素品质提升、产业结构高阶演进以及政府与市场作用协同发挥等领域给出相关建议,力争推动特殊类型地区在要素禀赋改善与产业结构优化良性互动中实现高质量发展。 展开更多
关键词 特殊类型地区 要素禀赋 产业结构 区域共同富裕 原连片特困区
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中西非裂谷系富油凹陷石油地质特征与勘探方向 被引量:1
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作者 窦立荣 史忠生 +1 位作者 庞文珠 马峰 《石油勘探与开发》 EI CSCD 北大核心 2024年第1期1-13,共13页
基于地震、钻井、烃源岩测试分析等资料,对中西非裂谷系主要盆地富油凹陷石油地质特征进行研究,并探讨未来油气勘探方向。研究表明:中非裂谷系发育下白垩统湖相优质烃源岩,西非裂谷系发育上白垩统陆源海相优质烃源岩,两类烃源岩为中西... 基于地震、钻井、烃源岩测试分析等资料,对中西非裂谷系主要盆地富油凹陷石油地质特征进行研究,并探讨未来油气勘探方向。研究表明:中非裂谷系发育下白垩统湖相优质烃源岩,西非裂谷系发育上白垩统陆源海相优质烃源岩,两类烃源岩为中西非裂谷系油气富集提供了物质基础。中西非裂谷系发育包括基岩在内的多套储集层,并存在下白垩统、上白垩统和古近系3套区域盖层。晚中生代以来,受中非剪切带右旋走滑作用等地球动力学因素的影响,中西非裂谷系不同方向的盆地在裂谷作用期次、区域盖层发育层段、圈闭类型及成藏模式等方面存在差异。其中,北东—南西向盆地主要保存了早白垩世一期裂谷层序,区域盖层位于下白垩统裂陷期地层内,形成反转背斜、花状构造及基岩潜山等圈闭类型,发育“源储一体、源内成藏”及“源上储下、源下成藏”两种成藏模式;北西—南东向盆地具有多期裂谷叠置特征,发育上白垩统和古近系区域盖层,形成披覆背斜、断背斜、反向断块等圈闭类型,以“源下储上、源上成藏”为主要成藏模式。多期叠置裂谷盆地的源内成藏组合、强反转盆地的源内岩性油藏及页岩油是中西非裂谷系盆地未来勘探的重要领域。 展开更多
关键词 烃源岩 区域盖层 圈闭类型 成藏模式 富油凹陷 中非剪切带 中西非裂谷系
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