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31.
基于CMIP5模式的中国气候变化敏感性预估与分析   总被引:4,自引:0,他引:4  
以CMIP5提供的26个全球气候系统模式的温度和降水数据为基础,采用区域气候变化指数(Regional Climate Change Index,RCCI)分析中国的不同区域对21世纪气候变化响应的敏感性。结果表明,三种排放情景(RCP 2.6、RCP 4.5、RCP 8.5)下,21世纪全期,气候变化最敏感的区域分布在西藏地区,其次为我国西北地区以及东北地区,气候变化敏感性最低的区域分布在我国内蒙古中东部、华北地区以及长江中下游一带,且高排放情景对应更高的气候变化敏感性。对RCCI指数贡献因子分析结果表明,对中国气候变化敏感性贡献的大小依次为Δσ_TΔσ_pΔRRWAF。冬夏两季温度变化的大值区与RCCI指数的大致区分布一致,RCCI大小的分布很大程度上由温度变化的敏感性决定。而夏季降水变化的大值区主要出现在西藏地区、华南地区和东北地区,冬季降水变化的大值区则主要出现在黄河以南长江以北的中原地区以及东北地区。  相似文献   
32.
The Qingling–Bashan (QB) mountain region in southern Shaanxi mainly consists of strongly compressive zones from east to west, with tight folds and compressive fractures. There is a wide distribution of soft rocks of various types, such as phyllite and slate, accompanied by complex geological structures. Ironically, tunnel construction in these difficult grounds with complicated geological conditions embraces a high risk of extreme deformation due to various unpredictable reasons, which can frequently cause collapse and result in budget overruns during the construction period. Therefore, it is crucial to conduct effective countermeasures to eliminate or avoid such adverse impacts. This paper provides a case study on the “Yingfeng tunnel” (a tunnel constructed in soft rock consisting of a slate ground) based on a geological survey, indoor experiments and in situ monitoring. A successive rock mass deformation resulted in the tunnel lining seriously intruding into construction clearance and some other sections, even collapsing during the construction. The maximum displacement amount was 62.5 cm, while the maximum deformation speed reached as high as 34.18 mm/day. Additionally, to evaluate the construction impacts of tunnelling-induced geo-hazards, an investigation on extreme deformation was conducted. Considering the time-dependent features of the rock mass deformation, the constraint-convergence method was used to put forward applicable countermeasures in this paper. Finally, from the feedbacks of monitoring results, extreme deformation of the Yingfeng tunnel was effectively controlled.  相似文献   
33.
Damage and destruction to schools from climate-related disasters can have significant and lasting impacts on curriculum and educational programs, educational attainment, and future income-earning potential of affected students. As such, assessing the potential impact of hazards is crucial to the ability of individuals, households, and communities to respond to natural disasters, extreme events, and economic crises. Yet, few studies have focused on assessing the vulnerability of schools in coastal regions of the USA. Using Hurricane Ike’s tropical storm wind swath in the State of Texas as our study area, we: (1) assessed the spatial distribution patterns of school closures and (2) tested the relationship between school closure and vulnerability factors (namely physical exposure and school demographics) using zero-inflated negative binomial regression models. The regression results show that higher probabilities of hurricane strikes, more urbanized school districts, and school districts located in coastal counties on the right side of Ike’s path have significant positive associations with an increase in the number of school closure days. Socioeconomic characteristics were not significantly associated with the number of days closed, with the exception of proportion of Hispanic youth in schools, a result which is not supported by the social vulnerability literature. At a practical level, understanding how hurricanes may adversely impact schools is important for developing appropriate preparedness, mitigation, recovery, and adaptation strategies. For example, school districts on the right side of the hurricane track can plan in advance for potential damage and destruction. The ability of a community to respond to future natural disasters, extreme events, and economic crises depends in part on mitigating these adverse effects.  相似文献   
34.
Large-scale damage to the power infrastructure from hurricanes and high-wind events can have devastating ripple effects on infrastructure, the broader economy, households, communities, and regions. Using Hurricane Irma’s impact on Florida as a case study, we examined: (1) differences in electric power outages and restoration rates between urban and rural counties; (2) the duration of electric power outages in counties exposed to tropical storm force winds versus hurricane Category 1 force winds; and (3) the relationship between the duration of power outage and socioeconomic vulnerability. We used power outage data for the period September 9, 2017–September 29, 2017. At the peak of the power outages following Hurricane Irma, over 36% of all accounts in Florida were without electricity. We found that the rural counties, predominantly served by rural electric cooperatives and municipally owned utilities, experienced longer power outages and much slower and uneven restoration times. Results of three spatial lag models show that large percentages of customers served by rural electric cooperatives and municipally owned utilities were a strong predictor of the duration of extended power outages. There was also a strong positive association across all three models between power outage duration and urban/rural county designation. Finally, there is positive spatial dependence between power outages and several social vulnerability indicators. Three socioeconomic variables found to be statistically significant highlight three different aspects of vulnerability to power outages: minority groups, population with sensory, physical and mental disability, and economic vulnerability expressed as unemployment rate. The findings from our study have broader planning and policy relevance beyond our case study area, and highlight the need for additional research to deepen our understanding of how power restoration after hurricanes contributes to and is impacted by the socioeconomic vulnerabilities of communities.  相似文献   
35.
2021年6-9月广西经历了1951年以来最高的月平均气温,大范围高温天气频发.利用1961-2021年广西国家地面气象观测站日平均气温和日最高气温观测资料、1991-2021年ERA5再分析资料和西太平洋副热带高压指数资料,对此次广西异常高温的特征和成因进行了研究分析.结果 表明,气候变暖是导致此次高温事件的重要气候背景,西太平洋副热带高压异常偏强位置偏西偏北、中纬度西风带扰动影响偏北以及热带气旋影响偏弱是造成广西气温异常偏高的主要原因.  相似文献   
36.
37.
Qin  Zipeng  Lai  Yuanming  Tian  Yan 《Natural Hazards》2021,109(1):567-592
Natural Hazards - The wind wave erosion is one of the main factors of the soil bank slope retreat in plain irrigation reservoirs, which plays an important role in the bank profile evolution and...  相似文献   
38.
为了研究震源区介质的物性特征,利用振幅谱拟合和有限差分三维Q值成像方法处理了伽师地震区临时台网的地震波形资料,获得了该地震区上地壳的S波三维Q值图像。结果表明:不同深度的Q值图像都存在低Q值带,主要展布方向为EW向、NNE向和NNW向,与研究区的柯坪断裂、羊达曼断裂和麦盖提断裂有一定的对应关系,并且NNE向的低Q值带与强震群分布和余震分布的条带位置接近,推测低Q值带可能是震源区的几条深部断裂。  相似文献   
39.
预应力混凝土连续梁桥振动特性变异及舒适度评价   总被引:2,自引:1,他引:1  
由于预应力损失、混凝土收缩徐变、超载等原因,预应力混凝土桥梁出现了较强的振动。本文通过对福建省福州市闽江三桥全桥环境振动试验和正常运营条件下24小时的监测,研究预应力混凝土连续梁桥的动力特性及其变异和振动舒适度,结果表明:在较为稳定的风和温湿度环境下,固有频率在一天内的最大变化为3.06%,模态阻尼比的最大变化为37.93%,舒适度的狄克曼指标降到“能忍受短时间振动”的区域。  相似文献   
40.
考虑双向水平地震作用的结构设计问题研究   总被引:1,自引:0,他引:1  
分析了抗震设计中考虑双向水平地震作用的必要性,指出了研究双向地震作用的必要性,通过国内外规范相关条文的对比指出目前研究有待完善的关键问题和方向,结合近期研究成果对其中几个值得注意的问题提出建议。  相似文献   
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