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131.
132.
Conductivity anomalies in the Baltic Shield in Finland 总被引:1,自引:0,他引:1
Kari Pajunpää 《Geophysical Journal International》1987,91(3):657-666
In 1981–84 six arrays of 30 or 31 magnetometers were operated on the Baitic Shield in central and southern Finland to deduce information about the electrical conductivity within the Earth's crust. The magnetometer sites cover the area with 20–60 km spacing allowing the identification of large-scale electrical structures within the crust. Each array recorded the three orthogonal magnetic field components on analogue film for about two months simultaneously at all the stations. Altogether 17 magnetic variation events of 2–6hr length have been digitized and analysed.
This paper includes results of the last array in south-western Finland, a comparison of two methods of induction vector estimation and combination of results from all the arrays. Four zones of anomalously high electrical conductivity have been observed. They are all interpreted as lying at depths greater than 5 km. The 'Oulu Anomaly' is wider than the others and rather short, about 100 km. The 'Southern Finland Anomaly' is probably a 500 km-long narrow zone. This and the 'Ostrobothnian Anomaly' surround three sides of the large Central Finland Granite area. The 'Outokumpu Anomaly' is probably deeper lying than the others. Blocks separated by these anomalies are presented. The blocks have different average resistivities. 相似文献
This paper includes results of the last array in south-western Finland, a comparison of two methods of induction vector estimation and combination of results from all the arrays. Four zones of anomalously high electrical conductivity have been observed. They are all interpreted as lying at depths greater than 5 km. The 'Oulu Anomaly' is wider than the others and rather short, about 100 km. The 'Southern Finland Anomaly' is probably a 500 km-long narrow zone. This and the 'Ostrobothnian Anomaly' surround three sides of the large Central Finland Granite area. The 'Outokumpu Anomaly' is probably deeper lying than the others. Blocks separated by these anomalies are presented. The blocks have different average resistivities. 相似文献
133.
Marcia J. Rieke 《Experimental Astronomy》1994,3(1-4):9-16
The 256×256 HgCdTe arrays developed for the NICMOS (Near-Infrared Camera and Multi-object Spectrometer) project have proven to be very capable devices for extragalactic imaging. This paper describes a sampling of extragalactic results from NICMOS arrays. A brief summary of the history of the development of these arrays, and their outstanding performance characteristics is also given. 相似文献
134.
Elimination of Swimming Pool Water Disinfection By‐products with Advanced Oxidation Processes (AOPs)
Ozonation is a treatment step which was first applied in the 1960s in pool water treatment for disinfection as well as for oxidation of pool water contaminants. Contact time between ozone and pool water was identified to be of significance with an increased elimination efficiency regarding chloramines, trihalogenmethane formation potential and the permanganate index for longer reaction times. Oxidation via OH radicals might be the dominating pathway. In this study ozonation was compared with the ozone based advanced oxidation processes ozone/UV and ozone/hydrogen peroxide regarding the elimination efficiency of both disinfection by‐products (DBPs) and DBP precursors. It was observed that AOPs in comparison to ozonation showed an increased elimination efficiency regarding total organic carbon (TOC), the organically bound halogens adsorbable on activated carbon (AOX) and AOX formation potential. A contact time of 3 minutes between pool water and oxidant turned out to be practically sufficient. Just for the trihalomethane (THM) formation potential ozonation showed a slight advantage compared to the AOPs because ozonation is a highly selective oxidant and OH radical reactions are known to produce small reactive molecules which are easier transformed to THMs. Combination of membrane filtration and AOPs resulted in an elimination of 10 to 90 % of the DBPs and their precursors. The ozone/hydrogen peroxide process is suggested for pool water treatment because of the higher elimination rates compared to ozonation and of economic reasons compared to the ozone/UV process. 相似文献
135.
In natural systems heavy metals are present in very low concentrations (less than micro-molar) , so precise measurement of the free metal ions is difficult. Recently, a new method has been developed called the Donnan membrane technique (DMT). Several heavy metals could be measured simultaneously using this method. Furthermore, all the metals did not interfere with each other, and the balance between the measured system and the surrounding condition could not be disturbed. Improvements were made according to the internal condition. The free heavy metal ion concentrations were measured in different systems using the improved method, and satisfied results have been obtained. 相似文献
136.
Nonlinearity in the response of soils in the 1995 Kobe earthquake in vertical components of records 总被引:4,自引:0,他引:4
Strong motion records provided by seismic vertical arrays allow estimation of stress–strain relations in soils at depths from the surface to the location of the deepest device. As an example, time-dependent nonlinear soil behavior was estimated in vertical components of records obtained in the epicentral area of the 1995 Kobe earthquake. Degradation of the rigidity of soils in the strong motion was observed. The constructed nonlinear models of the soil behavior were used for estimating the nonlinear parts in the ground response by the nonlinear system identification technique. Nonlinear parts in the ground response were found to be as high as 50% at 2 km from the fault and 10% at 6–15 km from the fault plane. Odd types of nonlinearity, such as cubic, the fifth, seventh, etc. order, were found to be typical for soils, whereas, nonlinearities of even types are usually weak, but increase in liquefied soils. 相似文献
137.