全文获取类型
收费全文 | 165篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 20篇 |
地球物理 | 46篇 |
地质学 | 56篇 |
海洋学 | 21篇 |
天文学 | 16篇 |
综合类 | 1篇 |
自然地理 | 7篇 |
出版年
2024年 | 1篇 |
2021年 | 1篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 15篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 2篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1963年 | 2篇 |
排序方式: 共有173条查询结果,搜索用时 109 毫秒
1.
2.
The use of rogation ceremony records in climatic reconstruction: a case study from Catalonia (Spain)
The use of rogation ceremonies due to environmental causes constitutes an important source of information in paleoclimatic reconstructions. Their specific characteristics and full documental records permit highly reliable series to be reconstructed with daily, monthly, seasonal or annual resolution over periods of several centuries (3–4 centuries in the case of Catalonia). The levels of intensity, reflected in the type of religious ceremony enacted, allows quantification. Comparative analysis is made possible by the similarity of the mechanisms developed in different localities. The use of these series in paleoclimatological studies is a promising line of research, particularly as regards the pro pluvia rogations celebrated in the Mediterranean countries and in South America. 相似文献
3.
Mariano Barriendos Javier Martín-Vide Juan Carlos Peña Roberto Rodríguez 《Climatic change》2002,53(1-3):151-170
Meteorological observations in the city of Cádiz are acknowledged as having been made from the middle of the 18th century onwards although they were only recorded and preserved in documentary form from 1789 onwards. Data readings were taken at the new Naval Observatory in San Fernando, ten kilometres from Cádiz, from 1797 onwards. Continuous series for temperature and atmospheric pressure at a daily resolution have been compiled and constructed from 1817 until 1996. The data series is composed of thrice daily observations made at Cádiz (1821–1880) by local observers and hourly data from Naval Observatory at San Fernando (1870–1996). 相似文献
4.
An earthquake of magnitude 7.2 on the Richter scale occurred on 12 November 1999 in the Düzce-Bolu region of Turkey. The region was also hit approximately 3 months before during the devastating Kocaeli earthquake of 17 August 1999. Besides high casualties and damage to various engineering structures and buildings, slope and embankment failures on the highway and the country roads occurred. In this study, the authors are concerned with the back-analysis of an embankment failure that occurred on the four lanes E-5 highway connecting Ankara to Gstanbul at Bakacak in the Bolu Province during the 1999 Düzce earthquake. Both pseudo-dynamic and dynamic limiting equilibrium methods are used to back analyse the conditions for the initiation of failure and also displacement responses of the embankment during the earthquake shaking. After having given a brief summary of the investigations on the post-failure state, the geology and geotechnical characteristics of the site, and the dynamic limiting equilibrium method developed and used for analyses are described. The results of the back-analysis based on a pseudo-dynamic approach, revealed that the maximum ground acceleration to initiate the failure of the embankment was probably about 0.125 g. On the other hand, the application of a method for computing the displacement and velocity responses of the failed embankment showed that the failure was possible when the embankment was subjected to ground accelerations similar to that recorded at the Düzce station. In addition, the computations also revealed that the time history of accelerations could be very important for the failure of slopes and embankments. 相似文献
5.
Underground cities and semi-underground settlements, most of which are 1500 years at least, exist in the Cappadocia Region of Turkey. These man-made rock structures are carved in soft tuffs and the best examples of long-term performance of man-made structures in the field of rock engineering. The tuffs also have good thermal isolation properties to be used as housing and storage of foods. In this article, the authors are only concerned with physical and short-term mechanical characteristics due to the wide-spectrum of the theme and the in situ characterization of the Cappadocia tuffs, and the results of investigations are presented. In addition, a critical overview on possible engineering geological problems at Cappadocia with mechanical aspects of historical and modern rock structures and their implications in rock engineering is made. From the experimental results in the field, it is evident that the engineering characteristics of these rocks do not show significant changes in vertical and horizontal directions. However, they are prone to atmospheric conditions. In addition, temperature and humidity measurements at different floors of the underground cities and various parts of semi-underground settlements indicated that variations in climatic conditions of the openings are very small when compared to those outside the ground surface. 相似文献
6.
7.
The regional influence of the Madden–Julian oscillation (MJO) on South America is described. Maps of probability of weekly-averaged rainfall exceeding the upper tercile were computed for all seasons and related statistically with the phase of the MJO as characterized by the Wheeler–Hendon real-time multivariate MJO (RMM) index and with the OLR MJO Index. The accompanying surface air temperature and circulation anomalies were also calculated. The influence of the MJO on regional scales along with their marked seasonal variations was documented. During December–February when the South American monsoon system is active, chances of enhanced rainfall are observed in southeastern South America (SESA) region mainly during RMM phases 3 and 4, accompanied by cold anomalies in the extratropics, while enhanced rainfall in the South Atlantic Convergence Zone (SACZ) region is observed in phases 8 and 1. The SESA (SACZ) signal is characterized by upper-level convergence (divergence) over tropical South America and a cyclonic (anticyclonic) anomaly near the southern tip of the continent. Impacts during March–May are similar, but attenuated in the extratropics. Conversely, in June–November, reduced rainfall and cold anomalies are observed near the coast of the SACZ region during phases 4 and 5, favored by upper-level convergence over tropical South America and an anticyclonic anomaly over southern South America. In September–November, enhanced rainfall and upper-level divergence are observed in the SACZ region during phases 7 and 8. These signals are generated primarily through the propagation of Rossby wave energy generated in the region of anomalous heating associated with the MJO. 相似文献
8.
9.
Linear discriminant analysis to describe the relationship between rainfall and landslides in Bogotá, Colombia 总被引:1,自引:0,他引:1
Alfonso Mariano Ramos-Cañón Luis Felipe Prada-Sarmiento Mario Germán Trujillo-Vela Juan Pablo Macías Ana Carolina Santos-R 《Landslides》2016,13(4):671-681
Bogotá is located in the central Andean region of Colombia, which is frequently affected by landslide processes. These processes are mostly triggered during the rainy season in the city. This fact remarks the importance of determining what rain-derived parameters (e.g. intensity, antecedent rain, daily rain) are better related with the occurrence of landslides. For this purpose, the linear discriminant analysis (LDA), a technique derived from multivariate statistics, was used. The application of this type of analysis led to obtain simple mathematical functions that represent the probability of occurrence of landslides in Bogotá. The functions also allow to identify the most relevant variables derived from records of rainfall linked to the generation of landslides. A proof of concept using the proposed methodology was done using historic rainfall data from a 9-km2 area of homogenous climatology and geomorphology in the south part of Bogotá. Landslides needed to be grouped for the LDA. Each one of these grouping categories represents landslides that occurred in similar geomorphologic conditions. Another set of events with no landslides was generated synthetically. Results of the proof of concept show that rainfall parameters such as normalized rainfall intensity I MAP, normalized daily rainfall R MAP and rainy-days normal RDN have the best statistical correlation with the landslides observed in the zone of analysis. 相似文献
10.
D. M. Cocârţă S. Neamţu A. M. Reşetar Deac 《International Journal of Environmental Science and Technology》2016,13(8):2025-2036
Human activities have progressively increased in recent years. Consequently, significant environment deterioration resulted. Soils have a particularly varied vulnerability to heavy metal pollution, especially in the vicinity of industrial areas. Heavy metal contamination of soil may induce risks and hazards to humans and the ecosystem, while toxic metals in soil can severely inhibit the biodegradation of organic contaminants. This paper is focused on human health risk assessment from extremely contaminated soil with heavy metals, mainly with carcinogenic elements. The study refers to an agricultural area in the vicinity of an old metallurgical processing industrial facility. The contaminants evaluated in the present paper are beryllium (Be), cadmium (Cd), chromium (Cr), nickel (Ni) and lead (Pb). Contamination level is pointed out through laboratory analysis results of soil samples taken from 0–0.2 m, 0.2–0.4 m soil layers and up to 2.1 m soil depth. Some heavy metal concentrations (Cd, Cr and Pb) exceed the intervention thresholds for sensitive areas, as they are stipulated in the national regulation in Romania. The identified average concentration levels of Cd, CrVI and Pb in the first layer of the investigated land are 23.83, 7.71 and 704.22 mg/kgd.w, respectively. The results show that the potential risk of human health is relevant (higher than the acceptable one after World Health Organization) and a possible solution for the remediation should become a major concern for the investigated area. 相似文献