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571.
Empirical Orthogonal Function (EOF) analysis and the related Principal Components (PC) analysis are used to extract valuable vegetation cover derived information from the National Oceanic and Atmos-pheric Administration (NOAA-AVHRR)'s Leaf Area Index (LAI) satellite images. Results suggest that from 1982 to 2000 global climate change has contributed to an increase in vegetation cover in the Qinghai-Tibet Plateau. The correlation between rainfall and LAI EOF PC1 and PC2 indicates that rainfall is the major climatic factor influencing interannual variations of average vegetation cover throughout the entire Plateau. However, annual mean vegetation cover trends in the Qinghai-Tibet Plateau are mainly out of phase with air temperature increasing, which is primarily responsible for nonsynchro-nous changes of vegetation cover. In the southern ridge of the Qinghai-Tibet Plateau, recent warming trends contribute to humid weather and favorable conditions for vegetation growth. By contrast, higher temperatures have led to arid conditions and insufficient rainfall in the northern part of the Plateau, leading to drought and other climatic conditions which are not conducive to increased vegetation cover.  相似文献   
572.
青藏高原东缘及四川盆地晚中生代以来隆升作用对比研究   总被引:11,自引:0,他引:11  
通过系统对比磷灰石裂变径迹数据,从整体上探讨了青藏高原东缘地区与四川盆地各地质单元在晚中生代、新生代抬升冷却特征.它们的构造活动在空同上具有分区性和连续性特征,在时间上具有幕武性特点.构造活动的空间上分区性表现在各地质单元隆升特征的差异性,主要为四川盆地川东北一川西南地区及其相邻两侧单元对比的差异和松潘一甘孜造山带南北地区的差异.空同上的连续性表现在中生代一新生代构造活动具有由北向南逐渐迁移的趋势,即由北向南磷灰石裂交径迹年龄减小和径迹长度增大的趋势.构造活动时间的幕式性表现在阶段性的快速冷却(埋深)及其相问的缓慢冷却过程.青藏高原东缘和四川盆地各地质构造单元径迹年龄值及年龄交化范围具有由西向东逐渐增大、径连长度逐渐减小的趋势,它们在晓中生代一新生代共处于统一的、递进的挤压变形动力学体制下,从西向东构筑成一个有机联系的挤压-抬升体系,其新生代构造抬升运动主要受控于喜马拉雅构造运动,同时也受中央造山带和扬子板块的重要影响.青藏高原东缘新近纪龙门山遣山带隆升速率最快(大干600 m/Ma),隆升幅度大于3 km,甚至超过6 km.  相似文献   
573.
The heating sources over the Tibetan Plateau (TP), the East Asian plain, and the western North Pacific (WNP) form a terraced thermal contrast in the west-east direction. Over East Asia and the WNP, this zonal thermal contrast contributes as high as 45 % to the seasonal variance based on the EOF analysis and exerts a significant impact on the seasonal transition of the East Asian climate through the enhancement of the year-round southerly to the southeast of the TP in late March and early April. This effect is investigated in this study using a high-resolution regional atmospheric model by doubling the surface sen- sible heat flux, respectively, over the TP, the East Asian plain, and the WNP in three sensitivity experiments. Comparisons among the experiments reveal that doubling the surface sensible heat flux over the WNP has little upstream response over East Asia. The increased zonal thermal contrast between the TP and the East Asian plain due to doubled heat flux over the TP would induce anomalous northerly over the region with year-round southerly to the southeast of the TP and weaken its seasonal enhancement. Doubling the surface sensible heat flux over the East Asian plain decreases the zonal thermal contrast and leads to southerly anomaly over the region with year-round southerly to the southeast of the TP and South China, which is favorable for the enhancement of the year-round southerly and its eastward extension.  相似文献   
574.
The near-surface freeze/thaw cycle in cold regions plays a major role in the surface energy budget,hydrological activity,and terrestrial ecosystems.In this study,the Community Land Model,Version 4 and a suite of high-resolution atmospheric data were used to investigate the changes in the near-surface soil freeze/thaw cycle in response to the warming on the Tibetan Plateau from1981 to 2010.The in situ observations-based validation showed that,considering the cause of scale mismatch in the comparison,the simulated soil temperature,freeze start and end dates,and freeze duration at the near-surface were reasonable.In response to the warming of the Tibetan Plateau at a rate of approximately 0.44°C decade-1,the freeze start-date became delayed at an area-mean rate of1.7 days decade-1,while the freeze end-date became advanced at an area-mean rate of 4.7 days decade-1.The delaying of the freeze start-date,which was combined with the advancing of the freeze end-date,resulted in a statistically significant shortening trend with respect to the freeze duration,at an area-mean rate of 6.4 days decade-1.Such changes would strongly affect the surface energy flux,hydrological processes,and vegetation dynamics.We also found that the rate of freeze-duration shortening at the near-surface soil layer was approximately 3.0 days decade-1lower than that at a depth of 1 m.This implied that the changes in soil freeze/thaw cycles at the near surface cannot be assumed to reflect the situation in deeper soil layers.The significant correlations between freeze duration and air temperature indicated that the shortening of the near-surface freeze duration was caused by the rise in air temperature,which occurred especially in spring,followed by autumn.These results can be used to reveal the laws governing the response of the near-surface freeze/thaw cycle to climate change and indicate related changes in permafrost.  相似文献   
575.
从建立信息化平台、制作微电影和微视频、打造微信息和QQ平台等方面,分析了蒙古族民族传统体育文化的有效传播方式.蒙古族民族传统体育文化传播与发展应重视文化内涵,关注系统性、注重多样性和迅捷性,提升监管力度,实现民族传统体育文化在人际、群体、组织和大众传播媒介的交流、互动和沟通,促进民族传统体育文化的传播与发展.  相似文献   
576.
文章以大量的历史文献论述了以饲养马、牛、羊等牲畜为主的畜牧业生产在青藏高原诸游牧民族的生产生活中占据着主导地位.明代至清前期,青藏高原地区的农业经济虽然有所发展,但由于自然条件的特殊性,畜牧业生产依然在社会经济生活中占据着主导地位,肩负着促进当地社会经济发展的任务,明清政府在高原地区和接近高原地区设置的官营茶马贸易和官办马场,客观上对民间畜牧产业的发展起到了推动作用.以史为鉴,如何在生态环境脆弱的条件下推动高原地区经济的发展,以满足当地人民日常生活所需也是我们当代人需要思考的问题.  相似文献   
577.
阿拉善地区降水同位素特征与水汽来源   总被引:2,自引:0,他引:2  
基于2013—2015年阿拉善高原阿右旗的降水氢氧稳定同位素组成数据,分析阿拉善高原降水δD和δ~(18)O的特征与变化规律,揭示当地的水汽来源与迁移路径。结果表明:(a)阿拉善高原降水δD和δ~(18)O的变化呈现明显的季节特征,即夏季偏高,冬季偏低。(b)主要气象参数(降水量、气温、大气湿度和风速)中,气温是控制阿拉善高原降水δD和δ~(18)O的主导因素;通过与周边区域的比较,阿拉善高原当地大气降水线的斜率和截距较低,这是由阿拉善高原降水受到非平衡蒸发作用强烈所致;(c)HYSPLIT气团轨迹模型模拟和降水同位素分析揭示了阿拉善高原阿右旗降水主要来自西风和极低气团。  相似文献   
578.
温泉蛇是我国青藏高原的特有种.它们是目前仅知可以分布在海拔4000米以上的唯一两种蛇之一,作者在恩师刘承钊院士的组织下,于1973年去西藏考察两栖爬行动物,曾到当雄羊八井采集和观察过温泉蛇,是我国学者观察研究温泉蛇的第一批人员.本世纪以来,虽然我又有机会组织去西藏考察,但年事已高,被同志们劝阻.幸此期我的中青年间事朋友们和研究生们先后有多人去西藏或四川理塘考察,我得以继续关注温泉蛇的研究进展.应中央民族大学生命与环境学院冯今朝院长之嘱,撰写此文,供有志于在青藏高原研究动物的同仁参考。  相似文献   
579.
探讨蒙药烧伤黄膏对输液性静脉炎的治疗作用.针对临床护理工作中造成输液性静脉炎的常见原因,开展预防护理和护理治疗对输液性静脉炎的防治是有积极作用的.  相似文献   
580.
结合蒙、中医有关理论,对“男女不孕不育症”进行了较为深入的研究,并根据医疗实践中获得的大量信息和满意的疗效,对该病的病因、分类及综合治疗提出了个人见解.  相似文献   
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