期刊文献+
共找到365篇文章
< 1 2 19 >
每页显示 20 50 100
A New Mamenchisaurid Dinosaur from the Middle Jurassic of Yuanmou,Yunnan Province, China 被引量:1
1
作者 LU Junchang LI Tianguang +2 位作者 ZHONG Shimin JI Qiang LI Shaoxue 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第1期17-26,共10页
A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is cha... A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod-like. Two fused centra of the posterior dorsal vertebrae (the presumed 9th and the 10th dorsal vertebrae) are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae. 展开更多
关键词 Eomamenchisaurus Mamenchisauridae SAUROPODA middle Jurassic yunnan province
下载PDF
COORDINATING DEVELOPMENT OF AGRICULTURAL RESOURCES AND ENVIRONMENT OF THE TROPIC REGION IN YUNNAN PROVINCE 被引量:1
2
作者 姚建衢 杨焕宗 《Chinese Geographical Science》 SCIE CSCD 1994年第4期345-351,共7页
The tropic region of Yunnan is a treasurable land with rich resources and great development potentials. The natural environment and resources of the region are characterized by a complicated topography, great height d... The tropic region of Yunnan is a treasurable land with rich resources and great development potentials. The natural environment and resources of the region are characterized by a complicated topography, great height deviation, monsoon climate as well as abound biological resources. Therefore, the tropic region becomes an ideal place for developing agricultural production base, though it do exist such problems as adverse location, sparsely distributed land resources, poor traffic conditions and deterioration of ecological environment. In order to further exploit the tropical resources and to implement comprehensive harnessing, we should take the following countermeasures:Working out a comprehensive development planning; restoring ecological environment,establishing agricultural production base; tapping fully water resources; constructing the traffic line and developing the border ports and tourism spots. 展开更多
关键词 TROPIC REGION coordinating DEVELOPMENT yunnan province
下载PDF
New Eusauropod Dinosaur from Yuanmou of Yunnan Province, China 被引量:6
3
作者 LUE Junchang LI Shaoxue +3 位作者 JI Qiang WANG Guofu ZHANG Jiahua DONG Zhiming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第1期1-10,共10页
Yuanmousaurusjiangyiensis gen. et sp. nov. is erected based on an incomplete skeleton. It is characterized by more complex structures of the neural arches in the dorsal vertebrae than those in Omeisaurus, but less com... Yuanmousaurusjiangyiensis gen. et sp. nov. is erected based on an incomplete skeleton. It is characterized by more complex structures of the neural arches in the dorsal vertebrae than those in Omeisaurus, but less complex than those of Euhelopus; the dorsal vertebra bears 9 laminae, forming three cavities on the lateral surface of the neural arch; the dorsal vertebral neural spines with dorsoventrally-oriented cavities are similar to those of Omeisaurus and Patagosaurus. Yuanmousaurus is more primitive than Euhelopus, but more derived than Omeisaurus. The similar dorsal vertebral structure between Yuanmousaurus and Patagosaurus may indicate that they have a close relationship to each other. 展开更多
关键词 Yuanmou yunnan province middle Jurassic Yuanmousaurus SAUROPODA
下载PDF
The impact of land use on soil properties in a karst agricultural region of Southwest China: a case study of Xiaojiang watershed, Yunnan 被引量:9
4
作者 Jiang Yongjun 《Journal of Geographical Sciences》 SCIE CSCD 2006年第1期69-77,共9页
Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soi... Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. (1) The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km^2, of which 134.29 km^2 of forestland was converted into cultivated land, and 210 km^2 of.unused land was converted into cultivated land. (2) The rapid growth of population and the economic development were the main driving forces of land use change. (3) With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g·kg^-1, 1.86 g·kg^-1, 1.63 g·kg^-1, 10.94 g·kg^-1, 114.42 g·kg^-1, 11.65 mg·kg^-1 and 64.69 mg·kg^-1g, respectively; and those in 2003 were 6.73, 25.26 g·kg^-1, 1.41 g·kg^-1, 0.99 g·kg^-1, 12.6 g·kg^-1, 113.43 mg·kg^-1, 11.11 mg·kg^-1 and 151.59 mg·kg^-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. (4) Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone. 展开更多
关键词 karst agricultural region land use change soil properties Xiaojiang watershed yunnan province
下载PDF
Seismic tomography of Yunnan region using short-period surface wave phase velocity 被引量:13
5
作者 何正勤 苏伟 叶太兰 《地震学报》 CSCD 北大核心 2004年第6期583-590,共8页
利用云南数字地震台网23个台站记录的短周期(1~18s)面波资料,用双台窄带通滤波互相关方法,测定了在209条路径上的基阶瑞利波相速度频散曲线,并通过层析成像反演得到各周期的相速度分布图象.给出了沿24°N,25°N,26°... 利用云南数字地震台网23个台站记录的短周期(1~18s)面波资料,用双台窄带通滤波互相关方法,测定了在209条路径上的基阶瑞利波相速度频散曲线,并通过层析成像反演得到各周期的相速度分布图象.给出了沿24°N,25°N,26°N及27°N和100.5°E的相速度频散剖面图.结果表明:云南地区的相速度分布图象具有强烈的横向变化,短周期段的相速度分布与沉积层厚度密切相关,中甸、丽江东部区域在约25km深度存在着明显的低速层,而畹町、云县、思茅一带在该深度范围是一明显的大面积高速区域.小江断裂与红河断裂围成的川滇菱形块体南段为低相速度区域.云南地区强震震中位置主要分布在相速度高速与低速过渡的区域. 展开更多
关键词 云南地区 瑞利波相速度 层析成像 地壳中上部 速度结构
下载PDF
Seismic tomography of Yunnan region using short-period surface wave phase velocity 被引量:8
6
作者 HE Zhengqin(何正勤) +3 位作者 SU Wei(苏伟) YE Tai-lan(叶太兰) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第6期642-650,共9页
The data of short-period (1~18 s) surface waves recorded by 23 stations belonging to the digital seismic network of Yunnan Province of China are used in this paper. From these data, the dispersion curves of phase velo... The data of short-period (1~18 s) surface waves recorded by 23 stations belonging to the digital seismic network of Yunnan Province of China are used in this paper. From these data, the dispersion curves of phase velocities of the fundamental mode Rayleigh wave along 209 paths are determined by using the two-station narrowband filtering cross-correlation method. Adopting tomography method, the distribution maps of phase velocities at various peri-ods in Yunnan region are inverted. The maps of phase velocities on profiles along 24N, 25N, 26N, 27N and 100.5E and the distribution maps of phase velocities at 3 periods in the study region are given. The results show that the phase velocity distribution in Yunnan region has strong variations in horizontal direction, and the phase velocity distribution in short-period range is closely related to the thickness of sedimentary layers in the shallow crust. The phase velocity in southern part of the Sichuan-Yunnan rhombic block encircled by the Honghe fault and Xiaojiang fault is obviously lower than that in surrounding areas. The epicentral locations of strong earthquakes in Yunnan region are mainly distributed in transitional zones between low and high phase velocities. 展开更多
关键词 yunnan region phase velocity of Rayleigh waves TOMOGRAPHY middle and upper crust velocity structure
下载PDF
The List of Wild Mammals of Illegal Trade in China
7
作者 殷西林 余经裕 彭建军 《Agricultural Science & Technology》 CAS 2016年第1期149-151,共3页
This paper illustrates the illegal trade of wild animals in China from 1996 to 2014 by referring to previously reported references and data. There have been83 species(22 families, 8 orders) of wild mammals illegally... This paper illustrates the illegal trade of wild animals in China from 1996 to 2014 by referring to previously reported references and data. There have been83 species(22 families, 8 orders) of wild mammals illegally traded and smuggled in China, mainly found in the southwest border, especially in Yunnan and Guangxi.Smuggling has seriously affected the ecological security of China, so it is necessary to intensify efforts to fight such crime, and enhance the people’s awareness of wildlife protection. 展开更多
关键词 Wild animal TRADE Guangxi Zhuang Autonomous Region yunnan province
下载PDF
滇中川街叶肢介Chuanjieestheria化石在冀北后城组的发现及其地质意义 被引量:2
8
作者 牛绍武 辛后田 《地质通报》 CAS CSCD 北大核心 2017年第6期909-912,共4页
滇中含中侏罗世海相化石地层之上连续沉积的麻地山组、安宁组和妥店组,时代应为晚侏罗世,产川街叶肢介、似东方叶肢介、云南雕饰叶肢介等化石,具有美丽的"滨生长线瘤"构造,形成特提斯区特有的叶肢介动物群。在冀北宣化堰家沟... 滇中含中侏罗世海相化石地层之上连续沉积的麻地山组、安宁组和妥店组,时代应为晚侏罗世,产川街叶肢介、似东方叶肢介、云南雕饰叶肢介等化石,具有美丽的"滨生长线瘤"构造,形成特提斯区特有的叶肢介动物群。在冀北宣化堰家沟后城组首次发现特提斯区极为发育的川街叶肢介化石,进一步证明后城组完全可以与滇中地区上侏罗统麻地山组-安宁组-妥店组对比,后城组的时代应为晚侏罗世,可能更近于晚侏罗世早—中期。川街叶肢介化石在后城组的发现,为环太平洋带的纯陆相后城组与特提斯区由海相化石推定的上侏罗统对比提供了古生物化石的有力佐证,具有重要的地层对比意义。 展开更多
关键词 滇中 上侏罗统 川街叶肢介Chuanjieestheria 冀北 后城组
下载PDF
Regional ecosystem health assessment using the GA-BPANN model:a case study of Yunnan Province,China 被引量:1
9
作者 Yuze Li Yuanxiang Wu Xiaoguang Liu 《Ecosystem Health and Sustainability》 SCIE 2022年第1期357-369,共13页
Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,mak... Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale. 展开更多
关键词 Neural network model regional ecosystem health assessment yunnan province
原文传递
基于华东区域模式云南短时强降水客观预报技术研究
10
作者 朱莉 许彦艳 +2 位作者 许迎杰 邱学兴 闵颖 《成都信息工程大学学报》 2024年第4期464-469,共6页
为提高云南短时强降水的预报效率和预报准确率,使用华东区域模式基础物理量数据,计算云南短时强降水发生前1 h 700 hPa相对湿度、700 hPa比湿、K指数和6 km垂直风切变,对短时强降水的历史个例进行物理量阈值训练和单物理量的敏感性实验... 为提高云南短时强降水的预报效率和预报准确率,使用华东区域模式基础物理量数据,计算云南短时强降水发生前1 h 700 hPa相对湿度、700 hPa比湿、K指数和6 km垂直风切变,对短时强降水的历史个例进行物理量阈值训练和单物理量的敏感性实验,确定物理量阈值。使用阈值判定法,对华东区域模式实时预报数据进行后处理,得到基于小时雨量和物理量的云南本地化短时强降水客观预报产品。研究结果表明:使用阈值判定法研发的基于华东区域模式云南短时强降水客观预报产品能较好地预报云南短时强降水的落区和走向,但是基于小时雨量的短时强降水客观预报产品漏报明显,基于物理量阈值的客观预报产品能有效降低云南短时强降水的漏报率。 展开更多
关键词 短时强降水 华东区域模式 阈值判定法 云南 客观预报产品
下载PDF
基于混合自组织映射神经网络的云南省山洪灾害危险性区划
11
作者 高耀 陈俊旭 +4 位作者 徐佳 吕丽花 梁宗玲 赵璐沅 王子尧 《云南大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第6期1067-1077,共11页
开展云南省山洪灾害危险性区划工作,以自组织映射神经网络为基础,混合Ward、PAM、CLARA、K-means和HK-means的5种方法进行二阶聚类,应用戴维森堡丁指数(Davies-Bouldin index,DBI)、轮廓系数(silhouette coefficient,SC)、聚类模型评估... 开展云南省山洪灾害危险性区划工作,以自组织映射神经网络为基础,混合Ward、PAM、CLARA、K-means和HK-means的5种方法进行二阶聚类,应用戴维森堡丁指数(Davies-Bouldin index,DBI)、轮廓系数(silhouette coefficient,SC)、聚类模型评估指数(Calinski-Harabaz index,CH)确定最佳聚类方案,之后以变异系数和变异系数一阶拆分确定最佳区划数量.结果显示:①SOM(self organizing map)+CLARA(clustering LARge applications)方法通过聚类有效性检验效果最好,其DBI值为1.0、SC值为0.9、CH值为0.3334,基于该方法得到云南省山洪灾害危险性最佳聚类数为5类,呈现类别空间分离,灾害属性相似的特征;②通过变异系数(coefficient of variation,CV)值变化及变异系数一阶差分(first-order difference,FOD)最低取值确定云南省山洪灾害危险性最佳区划单元为16个,具有形状上与地貌单元相近、数量上与行政单元相同,内部灾害发生机理相似的特征;③通过山洪灾害点、降水量、高程地貌的可视化比较,地理探测器定量分析,表明区划结果有较高的区内一致性和区间异质性. 展开更多
关键词 区划 山洪灾害危险性 两阶段混合聚类 自组织映射神经网络 云南省
下载PDF
Impact of changes in precipitation pattern on food supply in a monsoon interlacing area and its mechanism:A case study of Yunnan Province 被引量:3
12
作者 LIU Zhilin DING Yinping JIAO Yuanmei 《Journal of Geographical Sciences》 SCIE CSCD 2021年第10期1490-1506,共17页
Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This stud... Following climate change,changes in precipitation patterns and food security are major challenges faced by humans.However,research on how these changes in precipitation pattern impacts food supply is limited.This study aims to elucidate this impact and response mechanisms using precipitation data of a climate change-sensitive confluence zone of the southwest and southeast monsoons in Yunnan Province from 1988 to 2018.The results revealed that the precipitation pattern could be divided into three periods:abundant precipitation(Stage I,from 1988 to 2004),decreased precipitation(Stage II,from 2005 to 2015),and drought recovery(Stage III,from 2016 to 2018).Following the transition from Stage I to Stage II and from Stage II to Stage III,the area of precipitation changed significantly,accounting for 15.07%,13.87%,and 16.53%of Yunnan’s total area,for Stages I,II,and III,respectively.At the provincial level,a significant positive correlation was observed between precipitation and food production(r=0.535,P<0.01),and the correlation coefficient between precipitation and grain yield was higher than that between precipitation and meat and milk production.Based on a precipitation–grain yield transect and breakpoint detection method,key precipitation thresholds affecting grain yield were estimated as 700 and 1500 mm,respectively;when precipitation was<700,700–1500,and≥1500 mm,the correlation coefficients between precipitation and grain yield were 0.448(P<0.01),0.370(P<0.01),and–0.229(P>0.05),respectively.Based on the precipitation thresholds,Yunnan Province can be divided into precipitation surplus,precipitation equilibrium,and precipitation deficit regions,corresponding countermeasures to stabilize grain yield were proposed for each of these regions.The threshold effect of precipitation on grain yield is controlled by molecular-level water–crop mechanisms,in which reactive oxygen species,a by-product of plant aerobic metabolism,plays a key regulatory role. 展开更多
关键词 monsoon confluence region precipitation patterns food supply influencing mechanisms yunnan province
原文传递
云南山地碳汇造林投入产出效率研究——基于DEA-Tobit模型的腾冲市农户实证分析
13
作者 曾予心 苏建兰 《林业经济问题》 北大核心 2024年第4期347-356,共10页
在考虑碳汇生态价值补偿和林业生产效率的基础上,将碳汇收益纳入林业产出中,分析农户碳汇林投入产出效率的变动趋势。基于云南省腾冲市清洁发展机制小规模造林和再造林项目数据,分别运用三阶段DEA和Tobit模型对区域农户投入产出效率及... 在考虑碳汇生态价值补偿和林业生产效率的基础上,将碳汇收益纳入林业产出中,分析农户碳汇林投入产出效率的变动趋势。基于云南省腾冲市清洁发展机制小规模造林和再造林项目数据,分别运用三阶段DEA和Tobit模型对区域农户投入产出效率及其影响因素进行研究。研究表明,目前腾冲市农户碳汇造林生产经营处于规模效益上升阶段,投入产出效率值为0.598,较低的纯技术效率是制约生产效率提升的关键因素,不同项目区的生产效率存在显著差异;林业补贴政策对碳汇林生产效率具有显著正向影响,林地细碎化程度和采伐指标申请也对生产效率有积极作用,而市场距离和苗木价格对投入产出效率有负面影响。建议优化林业碳汇政策,提高农户参与碳汇造林的意愿,鼓励通过优化资源配置实现更高的投入产出效率,从而实现生态发展和农民增收的双赢。 展开更多
关键词 山地 碳汇造林 投入产出效率 DEA-TOBIT模型 云南省
下载PDF
文山州历代汉文碑刻史料价值述论
14
作者 高思涵 《玉溪师范学院学报》 2024年第4期39-46,共8页
碑刻是历史文化的重要载体之一。云南文山州存留了相当丰富的碑刻资源,是研究文山地区历史文化的宝贵资料。文山州所存的历代汉文碑刻,根据其内容可分为告示、诰命等规制文书类碑刻,交通建设、水利、生态环境类民生碑刻,儒学和书院建筑... 碑刻是历史文化的重要载体之一。云南文山州存留了相当丰富的碑刻资源,是研究文山地区历史文化的宝贵资料。文山州所存的历代汉文碑刻,根据其内容可分为告示、诰命等规制文书类碑刻,交通建设、水利、生态环境类民生碑刻,儒学和书院建筑相关的文化教育类碑刻,道教、佛教和民间信仰类宗教碑刻,人物家族碑刻5个类型,对深入研究文山州历史上政治、经济、文化、教育、交通、建筑等类问题有重要价值,对深入揭示文山地区历史文化发展有积极作用。 展开更多
关键词 文山州 历代汉文碑刻 史料价值
下载PDF
云南中三叠世罗平生物群产出地层的地球化学特征和沉积环境 被引量:24
15
作者 周长勇 张启跃 +4 位作者 吕涛 胡世学 谢韬 文芠 黄金元 《地质论评》 CAS CSCD 北大核心 2014年第2期285-298,共14页
为了研究安尼期罗平生物群产出地层的沉积环境,从云南罗平地区关岭组二段大凹子精测剖面采集50件样品进行了主量、稀土、微量元素分析。分析结果表明,所有灰岩样品的K、Na含量较低,Mg/ca比值也较低,反映罗平地区在中三叠世安尼期... 为了研究安尼期罗平生物群产出地层的沉积环境,从云南罗平地区关岭组二段大凹子精测剖面采集50件样品进行了主量、稀土、微量元素分析。分析结果表明,所有灰岩样品的K、Na含量较低,Mg/ca比值也较低,反映罗平地区在中三叠世安尼期为温暖潮湿的气候条件;Sr/Ba比值(1.22—68.96,平均值为24.35)较高,m值(=100×MgO/Al_2O_3)为27.22—27400,平均值达到1432,稀土元素较低的Y/Ho比值,表现出平缓或者微弱的LREE亏损,以及与近岸河口沉积物相似的稀土配分曲线特征,指示其属于近岸的碳酸盐台地内部盆地沉积。从剖面底部到顶部,Al、K、V、Ti和P等元素含量以及Co/Ti、Ni/Ti比值具有多个变化旋回,反映海平面升降变化频繁,总体发生了两次较大规模的海平面相对上升活动。所有样品的V/(V+M)、V/Cr、Ni/Co、U/Th等元素比值、δU、lg(Ce/Ce‘)等参数值都较高,反映沉积水体为相对低能、缺氧的环境。氧化还原敏感元素V、U、Co、Ni、Zn和cr等呈现出锯齿状曲线特征,表明水体并不完全处于缺氧环境,而是随着海平面周期性升降活动,底部水体表现为间歇性缺氧。结合地球化学及地层学资料,认为中三叠世安尼期罗平地区处于温暖潮湿、还原、低能的离岸较近台内盆地,这一时期海平面升降频繁,底部水体为间歇性缺氧环境。 展开更多
关键词 沉积环境 地球化学 罗平生物群 中三叠统 云南
下载PDF
滇中烤烟坡耕地地表径流氮素的动态变化特征 被引量:16
16
作者 宋娅丽 王克勤 +3 位作者 董莉 王帅兵 杨寿荣 张胜华 《水土保持学报》 CSCD 北大核心 2010年第4期7-11,共5页
采用野外田间试验定点监测的方法,通过研究滇中坡耕地地表径流中氮素流失的形态和浓度来反映氮素动态变化特征。结果表明:雨季氮素输出主要以径流为主,占流失量的64.86%。相同降雨条件下,不同处理三氮浓度均值均表现为:CK〈N1〈N2〈N3... 采用野外田间试验定点监测的方法,通过研究滇中坡耕地地表径流中氮素流失的形态和浓度来反映氮素动态变化特征。结果表明:雨季氮素输出主要以径流为主,占流失量的64.86%。相同降雨条件下,不同处理三氮浓度均值均表现为:CK〈N1〈N2〈N3〈N4〈N5,N5处理总氮和硝态氮浓度最高值达到5.52,4.36 mg/L,高出其他各处理的2.85-4.69倍和4.73-10.45倍,铵态氮浓度介于0.01-1.30 mg/L之间。滇中坡耕地地表径流输出主要以可溶态为主,可溶态氮中以硝态氮为主,硝态氮占全氮浓度比例为21.02%-83.55%,铵态氮仅占总氮的1.02%-38.58%。氮素各形态浓度与施肥量之间、总氮浓度与氮素输出量之间、施肥量与氮素输出量之间存在显著的线性关系,相关系数达到0.864 1-0.983 8。 展开更多
关键词 地表径流 硝态氮 铵态氮 坡耕地 滇中
下载PDF
川滇南部地区活动地块划分与现今运动特征初析 被引量:63
17
作者 向宏发 虢顺民 +2 位作者 徐锡伟 张晚霞 董兴权 《地震地质》 EI CSCD 北大核心 2000年第3期253-264,共12页
根据近几年取得的新资料和当今有关活动地块的研究 ,提出划分川滇南部活动地块的思路、依据和具体方法 ,作者认为具有一定规模且其活动性延续至今的第四纪活动断裂是划分活动地块必需的首要边界条件。指出新生的腾冲 -景洪北北西带和大... 根据近几年取得的新资料和当今有关活动地块的研究 ,提出划分川滇南部活动地块的思路、依据和具体方法 ,作者认为具有一定规模且其活动性延续至今的第四纪活动断裂是划分活动地块必需的首要边界条件。指出新生的腾冲 -景洪北北西带和大理 -楚雄北西西带在活动地块划分中的重要作用。根据断块边界断裂活动性质、运动方式和GPS资料等 ,分析讨论了各活动地块现今活动方式得出 :≥ 7级以上地震主要集中在Ⅰ级活动地块边界 ;6~ 7级地震主要集中发生在Ⅱ级活动地块边界上 ;Ⅲ级活动地块是强震发生的主要位置所在。 展开更多
关键词 活动地块 第四纪活动断裂 地震破裂带
下载PDF
云南水土流失态势、分区与区域特征研究 被引量:11
18
作者 万晔 韩添丁 +3 位作者 段昌群 史正涛 司徒群 王健萍 《中国沙漠》 CSCD 北大核心 2005年第3期442-447,共6页
水土流失分区是水土流失研究和水土保持管理的重要组成部分。笔者从云南省水土流失的基本情况分析入手,首先分析对比了1987年和1999年全省和六大流域水土流失的演变态势及其各侵蚀强度面积所占百分比,再以各区域不同的自然地理尤其是地... 水土流失分区是水土流失研究和水土保持管理的重要组成部分。笔者从云南省水土流失的基本情况分析入手,首先分析对比了1987年和1999年全省和六大流域水土流失的演变态势及其各侵蚀强度面积所占百分比,再以各区域不同的自然地理尤其是地貌、植被覆盖特点和陡坡耕地占耕地总面积的比例及所在区域农业人口密度,把全省分为7个水土流失自然区,并对每个自然区的水土流失现状、特点、趋势进行了分析。该研究对区域水土保持、生态环境建设和区域可持续发展有重要意义。 展开更多
关键词 水土流失 云南 水土保持 侵蚀强度面积 生态环境 区域可持续发展
下载PDF
云南省马铃薯种植区域分布和周年生产 被引量:45
19
作者 桑月秋 杨琼芬 +5 位作者 刘彦和 卢丽丽 李文娟 周俊 谢开云 隋启君 《西南农业学报》 CSCD 北大核心 2014年第3期1003-1008,共6页
通过调研云南省马铃薯种植区域分布和周年生产情况,对数据进行统计分析,其结果显示,马铃薯是云南省主要的优势农作物之一,分布在16个州市的128个县市区,总种植面积48.58万hm2,总产量950.8万t。以曲靖市、昆明市和昭通市为主产区,3个主... 通过调研云南省马铃薯种植区域分布和周年生产情况,对数据进行统计分析,其结果显示,马铃薯是云南省主要的优势农作物之一,分布在16个州市的128个县市区,总种植面积48.58万hm2,总产量950.8万t。以曲靖市、昆明市和昭通市为主产区,3个主产市的生产面积和产量分别是34.78万hm2和762.1万t,占全省的71.6%和76.4%。全省10大马铃薯主产县生产面积为25.92万hm2,总产量547.6万t,分别占全省的53.4%和57.6%。从周年分布状态来分析,大春马铃薯主要集中在宣威市、会泽县、镇雄县和昭阳区等县(市)种植,种植面积和产量分别占全省的66.1%和66.3%;小春马铃薯主要集中在陆良县、宣威市、广南县和腾冲县等县(市),种植面积和产量分别占全省的18.5%和19.6%;冬季马铃薯种植面积呈现逐年增加的态势,主要在巧家县、盈江县、建水县和泸水县等县,种植面积和产量分别占全省的8.6%和8.8%;而秋作马铃薯种植面积变化不大,主要集中在宣威市和陆良县种植,种植面积和产量分别占全省的6.8%和5.3%。 展开更多
关键词 云南省 马铃薯 区域分布 周年生产
下载PDF
地缘经济关系测度与分析的理论方法探讨——以云南省为例 被引量:51
20
作者 张学波 武友德 骆华松 《地域研究与开发》 CSSCI 北大核心 2006年第4期34-39,共6页
文章首先简要分析了地缘经济学的发展进程和研究内容,提出以保护国家利益增强综合国力为主要研究目的的地缘经济理论在一定程度上可以指导不同级别区域经济合作策略的制定。然后在探究了地缘经济关系涵义的前提下,设计了地缘经济关系的... 文章首先简要分析了地缘经济学的发展进程和研究内容,提出以保护国家利益增强综合国力为主要研究目的的地缘经济理论在一定程度上可以指导不同级别区域经济合作策略的制定。然后在探究了地缘经济关系涵义的前提下,设计了地缘经济关系的测度体系,并用该方法对云南省地缘经济关系进行了数量测度和类型判别,进而对该省地缘经济关系进行了分析和评价,对经济发展提出了建议。 展开更多
关键词 地缘经济学 地缘经济关系 欧氏距离 云南省
下载PDF
上一页 1 2 19 下一页 到第
使用帮助 返回顶部