全文获取类型
收费全文 | 43篇 |
免费 | 0篇 |
专业分类
测绘学 | 2篇 |
地球物理 | 5篇 |
地质学 | 22篇 |
海洋学 | 1篇 |
天文学 | 13篇 |
出版年
2021年 | 1篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有43条查询结果,搜索用时 78 毫秒
31.
32.
As in seen from comparisons of Mariner 9 images obtained in 1972 and Viking Orbiter 1 images obtained in 1978, several changes have occurred in the Cerberus region of Mars. Changes in the boundary of the low albedo feature resulted in an increase of the total area of Cerberus by slightly more than 1%, although the southwestern boundary had shifted as much as 90 km. Relative darkening of Cerberus has resulted in a more uniform tone, and is accompanied by the disappearance of dark filamentary markings. Although several bright streaks within Cerberus changed in length, neither lengthening nor shortening of the streaks predominated. However, changes in streak direction indicate a clockwise rotation of mean streak azimuth between 1972 and 1978. These changes in the outline and appearance of Cerberus can best be explained by eolian redistribution and removal of bright material during major dust storms. Volcanic flow fronts which show through the albedo feature indicate that the contrast between Cerberusand the surrounding light plains is not due to a difference in lithology, but to the distribution of surficial deposits. Because of local topographic influences on the regional atmospheric circulation patterns, it is probable that Cerberus will retain a similar appearance and location. 相似文献
33.
Farouk Mohammad El-Fawal Hesham Mostafa El-Asmar Mohammad Abd El-Fattah Sarhan 《Arabian Journal of Geosciences》2013,6(3):749-760
The Middle-Upper Eocene rocks of the Fayum District are represented by Gehannam, Birket Qarun and Qasr El-Sagha formations. Both field studies and laboratory analyses on the concerned rocks have enabled to distinguish six lithofacies: (1) sheet-like grey silt-shale, (2) large-scale trough cross-bedded sandstone, (3) successive varicolored mud-shale/siltstone intercalation, (4) dark grey to black mud-shale/sandstone intercalation, (5) thinly bedded sandstone-shale intercalation and (6) very large-scale cross-stratified sandstone. These lithofacies proved that the present rocks were deposited in transitional paralic environment of active northward-prograding deltaic subenvironments contemporaneous with rabid but gradual sea level drop. The depositional system started with the delta front silt-shale (Gehannam Formation) of 20 m thickness, followed by distributary mouth bars of cross-bedded sandstone (Birket Qarun Formation, 50 m thick). Both the lower and upper delta plains attain thicknesses of 99 and 38 m, respectively, and are represented by the lower part of Qasr El-Sagha Formation. The deltaic sequence is topped with 45-m-thick eolian sandstones representing the upper part of Qasr El-Sagha Formation. This unit represents an extensive desertification phase that closes the depositional history of the succession examined. 相似文献
34.
Farouk El-Baz 《地学学报》1990,2(5):446-454
Detailed knowledge of the natural resources of any nation is a pre-requisite for its economic development. In most developing countries, this knowledge is scarce or lacking. Acquiring the needed information by conventional means may require a large investment in time, personnel, and therefore, in cost. In the meantime, space-age technology provides the necessary tools to conduct surveys of natural resources in a timely manner. Such are the means to obtain the required data by digital sensors, radar imaging systems, and stereo cameras. These data can be utilized in mapping structures that may contain oil and gas deposits, recognizing high concentrations of economic minerals, discovering regions with fertile soils and good potential for groundwater, and monitoring cyclical climatic changes, particularly in arid lands. Such applications warrant greater use of remote sensing methods and techniques by the international scientific community, particularly for the development of natural resources in the Third World. This paper represents a general review of the available, and easily interpretable space-borne data that are useful in the mapping of such resources. 相似文献
35.
36.
Ahmed Farouk Kamel 《Natural Hazards》1994,9(1-2):235-245
Egypt had been subjected to earthquakes of various degrees but earthquake observation in this country started only in 1899. Earthquakes were found in the locations where fractures have relatives high densities.The Fracture pattern of Egypt south Latitude at 29° N was studied regionally based on Landsat images and aerial photomosaics. Fractures in the Eastern Desert have the prominent trends, NW, EW, NNW and ENE, showing high density in the northern and southern parts. These fractures control the distribution of mineral deposits and radioactivity in the basement rocks.Fractures in Western Desert are less remarkable with the main trend NNW, E-W, N-S and NW, showing high density in the central part. The NNW trending fractures have the same direction of sand dunes which cover larger areas in the northwestern part of Western Desert.Based on the geographical distribution of earthquakes in the seismic maps and centers of high fractures density on the structural contour maps, the area south of latitude 29° N of Egypt was divided into three regions: The Red Sea, Western Desert and Aswan Environs. This correlation led to the conclusion that the fractures have an effect on earthquake activity, are trending ENE and WNW in the Red Sea, NW and N-S in the Western Desert and E-W and NNW in Aswan Environs.It should be emphasized that fractures with higher density are more susceptible to earthquakes in the locations characterized by two dominant sets of fractures especially at their intersections. 相似文献
37.
Eltaweila Saeid Shahien Marawan M. Nasr Ahmed M. Farouk Ahmed 《Geotechnical and Geological Engineering》2021,39(6):4059-4070
Geotechnical and Geological Engineering - Soft clay soil extends in many areas all over the world. The construction on soft clay is one of the most important problems in engineering practice. When... 相似文献
38.
Al Ashi Aisha Wael Hneine Samia Mokh Marie-Hélène Devier Hélèn Budzinski Farouk Jaber 《Ocean Science Journal》2017,52(3):455-466
The aim of this study is to assess the dissolved concentration of 45 pesticides in the surface waters of the Lebanese Republic using Polar Organic Chemical Integrative Sampler "POCIS". All of the sampling sites are located in the major agricultural land areas in Lebanon. POCIS (n = 3) were deployed at Ibrahim River, Qaraoun Lake and Hasbani River for a duration of 14 days. The total concentration of pesticides ranged from not detected (nd) to 137.66 ng.L-1. Chlorpyrifos, DDE-pp, diazinon and Fenpropathrin were the most abundant compounds. Qaraoun Lake and Hasbani River were found to be more polluted than Ibrahim River, since they receive large amounts of waste water derived from nearby agricultural lands and they had the lowest dilution factor. The aqueous average concentration of the target compounds were estimated using sampling rates obtained from the literature. Comparison between Time Weighed Average concentrations "TWA" using POCIS and spot sampling is presented. Results showed that POCIS TWA concentrations are in agreement with spot sampling concentrations for Ibrahim and Hasbani Rivers. The toxicity of the major detected pesticides on three representative aquatic species (Daphnia magna, Scenedesmus quadricauda and Oncorhynchus mykiss) is also reported. 相似文献
39.
The first detailed biostratigraphic analyses of the Coniacian-middle Campanian shallow-marine carbonate successions exposed in the Mitla Pass, west central Sinai, Egypt have revealed the stratigraphic distribution of diverse calcareous nannofossil and planktonic foraminiferal species. Thirty-six calcareous nannofossils and thirty-two planktonic foraminifera are identified, indicating a Coniacian to middle Campanian age and four Tethyan planktonic foraminiferal and five calcareous nannofossil zones. A comparison of these bioevents from different palaeolatitudes shows considerable variation in age.Three sequence boundaries coincident with the Turonian/Coniacian, Coniacian/Santonian and Santonian/Campanian stage boundaries are recognized. A fourth sequence boundary is marked by a major upper Campanian to early Ypresian (early Eocene) unconformity. These sequence boundaries are primarily related to regional tectonism associated with the Syrian Arc Fold System and secondarily to eustatic sea-level fluctuations. 相似文献
40.
Abdel-Galil A. Hewaidy Medhat M. M. Mandur Sherif Farouk Ibrahim S. El Agroudy 《Arabian Journal of Geosciences》2016,9(2):159
Lower to Middle Miocene successions in three offshore wells named GS 160-2, QQ-89, and Ras Elush-2 located in the central and southern parts of the Gulf of Suez were examined for their planktonic foraminifera, calcareous nannofossil assemblages, and paleoenvironments. These successions are subdivided from older to younger into Aquitanian Nukhul, Burdigalian-Langhian Rudeis, Langhian Kareem, and Serravallian Belayim formations. The identified foraminifera includes 54 benthic species belonging to 25 genera and 47 planktonic species belonging to 11 genera, in addition to 64 calcareous nannofossil species belonging to 21 genera. The stratigraphic distribution of these assemblages suggests classifying the studied successions into seven planktonic foraminiferal and six calcareous nannoplankton biozones. The planktonic foraminiferal and calcareous nannoplankton biozones are integrated. Different environments ranging from shallow inner to outer shelf are recognized. This is based on quantitative analyses of foraminifera including benthic biofacies, planktonic/benthonic ratio, and diversity. Syn-rift tectonics played an important role in configuration of the Miocene depositional history in the Gulf of Suez region. 相似文献