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231.
Racial/Ethnic Intermixing in Intra-Urban Space and Socioeconomic Context: Columbus,Ohio and Milwaukee,Wisconsin 总被引:1,自引:0,他引:1
《Urban geography》2013,34(3):317-347
232.
233.
针对独立不等精度离散点的二次曲线拟合问题,以系数矩阵元素的一阶误差传播得到的方差为权倒数,采用加权总体最小二乘估计方法求解拟合参数,将加权总体最小二乘问题转化为Rayleigh商问题,从而只需求一正定矩阵的特征值和特征向量,便可通过迭代计算得到待估参数的解。该方法性能稳定且计算量较小,是针对WTLS问题的一种相对简捷高效的计算方法。 相似文献
234.
地震次生崩滑是震后较长时间内严重危害人们生活的地质灾害之一, 对其展开危险性评价具有重要意义。 本文选取2008年汶川地震的重灾区汶川县为研究区, 基于遥感数据, 利用GIS技术手段, 结合研究区地质环境背景进行地震次生崩滑危险性评价。 选取逻辑回归模型, 将研究区划分为不危险、 轻微危险、 较危险、 危险和极危险5个等级, 实现了基于Logistic模型的区域内地震次生崩滑地质环境危险性评价。 相似文献
235.
Mary E. Davis 《Marine Policy》2012,36(1):28-33
The dangers associated with commercial fishing are well documented, and fishermen consistently face one of the highest job-related mortality risks of all US occupations. This study explored fishermen's perceptions of these risks in a representative sample of Maine commercial fishing vessel captains. Data were collected on sociodemographic characteristics and risk preferences during sea boardings of working commercial fishing vessels (n=233) along the full extent of the Maine coastline. Trends in perceived risk were explored across the various sociodemographic categories. Fishermen in this study consistently undervalued their true occupational risk, and rated it as average despite consistent evidence to the contrary. Those more likely to downgrade the risk of fishing included state registered vessels and those found to be non-compliant with existing safety regulations. Less educated fishermen and those who come from a fishing family were also more likely to underrate the risks, as were those fishermen who displayed risk-loving tendencies in other facets of their lives such as smokers and those who did not use seat belts. Middle-aged fishermen were also more likely to underrate the risk than the youngest and oldest groups, suggesting that overconfidence grows and then wanes over time. The results of this study strongly suggest that the current safety training and awareness programs targeting fishermen are inadequate. Furthermore, widespread voluntary participation in organized safety training is unlikely since the majority of fishermen believed that the risks were not relevant to their own activities. 相似文献
236.
The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area. 相似文献
237.
Probabilistic landslide risk analysis considering direct costs in the area north of Lisbon (Portugal) 总被引:7,自引:1,他引:6
The purpose of the present study is the analysis of landslide risk for roads and buildings in a small test site (20 km2) in the area north of Lisbon (Portugal). For this purpose, an evaluation is performed integrating into a GIS information obtained from multiple sources: (i) landslide hazard; (ii) elements at risk; and (iii) vulnerability. Landslide hazard is assessed on a probabilistic basis for three different types of slope movement (shallow translational slides, translational slides and rotational slides), based on some assumptions such as: (i) the likelihood of future landslide occurrence can be measured through statistical relationships between past landslide distribution and specified spatial data sets considered as landslide predisposing factors; and (ii) the rainfall combination (amount–duration) responsible for past slope instability within the test site will produce the same effects (i.e. same type of landslides and similar total affected area), each time they occur in the future. When the return period of rainfall triggering events is known, different scenarios can be modelled, each one ascribed to a specific return period. Therefore, landslide hazard is quantitatively assessed on a raster basis, and is expressed as the probability for each pixel (25 m2) to be affected by a future landslide, considering a rainfall triggering scenario with a specific return period. Elements at risk within the test site include 2561 buildings and roads amounting to 169 km. Values attributed to elements at risk were defined considering reconstruction costs, following the guidelines of the Portuguese Insurance Institute. Vulnerability is considered as the degree of loss to a given element resulting from the occurrence of a landslide of a given magnitude. Vulnerability depends not only on structural properties of exposed elements, but also on the type of process, and its magnitude; i.e., vulnerability cannot be defined in absolute terms, but only with respect to a specific process (e.g. vulnerability to shallow translational slides). Therefore, vulnerability was classified for the three landslide groups considered on hazard assessment, taking into account: (i) landslide magnitude (mean depth, volume, velocity); (ii) damage levels produced by past landslide events in the study area; and (iii) literature. Finally, a landslide risk analysis considering direct costs was made in an automatic way crossing the following three layers: (i) Probabilistic hazard map for a landslide type Z, considering a particular rainfall triggering scenario whose return period is known; (ii) Vulnerability map (values from 0 to 1) of the exposed elements to landslide type Z; and (iii) Value map of the exposed elements, considering reconstruction costs. 相似文献
238.
Integration degree of risk in terms of scene and application 总被引:2,自引:2,他引:0
Chongfu Huang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(4):473-484
Risk is a scene in the future associated with some adverse incident. Scene means something seen by a viewer, or felt by individuals
or various societal groups. Any risk assessment is to model some aspects of the scene for risk. Different aspects for assessment
leads to different scene. In this paper, we suggest the integration degree of risk to distinguish characters of risks with
respect to the aspects. The total number of factors of a risk system determines the macro degree and the granulation scale
for measuring a risk reflects the micro degree. A simple framework depends on the degrees provides an explanation of the integrated
risk. The most common model for risk assessment is available for the two-freedom-degree serial risk. A case studying flood
risk shows the application to explain what the risk is, where the information is incomplete and we use the information diffusion
technique to estimate the risk.
Project 40771007 supported by National Natural Science Foundation of China. 相似文献
239.
Xiaobei Liang Demian Chen Da Ruan Bingyong Tang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(4):415-423
The financial supply chain is increasingly recognized as an area offering significant potential for generating bottom-line
improvements and creating competitive advantage. Insurers’ appraisal is one of the basic decisions for a company, and the
choosing course has always many criterions. Considering the stability of the financial supply chain, the coordination evaluation
and fuzzy multi-objective evaluation model of insurers’ risk management are firstly studied in this paper by using large system
theory and methods. The corresponding coordination evaluation index model is then established to evaluate, forecast and control
the actuality and the future of risk coordination management, and to improve the durative development for a combination pension
model. The evaluation standards of numerous insurers are established to constitute a set of vectors. By presenting a dimensional
point to each insurer, the optimal or the worst insurer is decided. Finally, the distances of each insurer to the optimal
or the worst insurer on the basis of the Euclidean distance are counted, and the insurers’ ordering according to the value
of distances is sorted out. The financial supply chain and large system theory and methods are combined to contribute new
evaluation models that revise the deficiency of intrinsic model and improve the financial stability. 相似文献
240.
Organotin contamination in seafood and its implication for human health risk in Hong Kong 总被引:1,自引:0,他引:1
Organotins (OTs) have caused widespread adverse effects on marine organisms, while they can also induce health problems to humans via consumption of contaminated seafood. This study aimed to quantify the tissue concentrations of OTs in 11 seafood species in Hong Kong, and assess the human health risk for consuming these species. The tongue sole Paraplagusia blochii had the highest concentration of total OTs. Triphenyltin (TPT) accounted for 56–97% of total OTs. The highest hazard quotient (HQ) for TPT was 1.41 in P. blochii, while the HQs for butyltins were much less than 1. The results indicated that it is likely to have certain health risks for consuming P. blochii due to its high TPT contamination. Therefore, TPT should be a priority pollutant of concern. Appropriate management actions should be taken to control its use and release in the region in order to safeguard the marine ecosystem and human health. 相似文献