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排序方式: 共有142条查询结果,搜索用时 15 毫秒
81.
John P. Ortiz Mark A. Person Peter S. Mozley James P. Evans Susan L. Bilek 《Ground water》2019,57(3):465-478
We used hydrogeologic models to assess how fault-zone properties promote or inhibit the downward propagation of fluid overpressures from a basal reservoir injection well (150 m from fault zone, Q = 5000 m3/day) into the underlying crystalline basement rocks. We varied the permeability of the fault-zone architectural components and a crystalline basement weathered layer as part of a numerical sensitivity study. Realistic conduit-barrier style fault zones effectively transmit elevated pore pressures associated with 4 years of continuous injection to depths of approximately 2.5 km within the crystalline basement while compartmentalizing fluid flow within the injection reservoir. The presence of a laterally continuous, relatively low-permeability altered/weathered basement horizon (kaltered layer = 0.1 × kbasement) can limit the penetration depth of the pressure front to approximately 500 m. On the other hand, the presence of a discontinuous altered/weathered horizon that partially confines the injection reservoir without blocking the fault fluid conduit promotes downward propagation of pressures. Permeability enhancement via hydromechanical failure was found to increase the depth of early-time pressure front migration by a factor of 1.3 to 1.85. Dynamic permeability models may help explain seismicity at depths of greater than 10 km such as is observed within the Permian Basin, NM. 相似文献
82.
Improvement in PWV estimation from GPS due to the absolute calibration of antenna phase center variations 总被引:1,自引:0,他引:1
Climatology of column-integrated atmospheric water vapor over Spain has been carried out by means of three techniques: soundings,
sun photometers and GPS receivers. Comparing data from stations equipped with more than one of these instruments, we found
that a large discontinuity occurred on November 6, 2006, in the differences between the data series from GPS receivers and
those from the other two techniques. Prior to that date, the GPS data indicate a wet bias of 2–3 mm for all stations when
compared with sounding or photometer data, whereas after that date this bias practically reduces to zero. The root mean square
error also decreases about half of its value. On November 6, 2006, the International GNSS Service adopted an absolute calibration
model for the antennas of the GPS satellites and receivers instead of the relative one. This change is expected to be an improvement,
increasing the accuracy of station position determination and consequently benefiting post-processing products such as zenith
total delay from which the atmospheric water vapor content is calculated. 相似文献
83.
G. Malcheva R. Mayo M. Ortiz J. Ruiz L. Engström H. Lundberg H. Nilsson P. Quinet É. Biémont K. Blagoev 《Monthly notices of the Royal Astronomical Society》2009,395(3):1523-1528
Radiative lifetimes of 17 excited levels in Zr i , in the energy interval 29 000–40 974 cm−1 , have been investigated using the time-resolved laser-induced fluorescence method. The levels belong to the 4d2 5s5p, 4d3 5p and 4d5s2 5p electronic configurations and were excited in a single-step process from either the ground term, 4d2 5s2 a 3 F, or from the low-lying 4d2 5s2 a 3 P and a 5 F terms. For three levels, we confirm previous measurements while for 14 of the levels the lifetimes have been measured for the first time. The experimental results are compared to theoretical calculations performed with a multiconfiguration relativistic Hartree–Fock method including core-polarization effects. Theoretical transition probabilities of astrophysical interest, scaled by the experimental lifetimes, for the depopulating channels of the investigated levels are also presented. 相似文献
84.
Although the identification of the moisture sources of a region is of prominent importance to characterize precipitation, the origin and amount of moisture towards the Indian Subcontinent and its relationship with the occurrence of precipitation are still not completely understood. In this article, the origin of the atmospheric water arriving to the Western and Southern India during a period of 5 years (1 January 2000–31 December 2004) is investigated by using a Lagrangian diagnosis method. This methodology computes budgets of evaporation minus precipitation by calculating changes in the specific humidity of thousands of air particles aimed to the study area following the observed winds. During the summer monsoon, the main supply of moisture is the Somali Jet, which crosses the equator by the West Indian Ocean. The recycling process is the main water vapour source in winter. Two additional moisture sources located over northwestern India and the Bay of Bengal are identified. A 30% increase in the moisture flux from the Indian Ocean has been related to the occurrence of strong precipitation in the area, and at the end of the monsoon, the recycling became a significant contribution to the last part of the wet season of Western and Southern India. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
85.
José E. Ortiz Arantxa Díaz-BautistaJuan José Aldasoro Trinidad TorresJosé Luis R. Gallego Laura MorenoBelén Estébanez 《Organic Geochemistry》2011,42(6):586-592
We determined the distribution of lipids (n-alkanes and n-alkan-2-ones) in present-day peat-forming plants in the Roñanzas Bog in northern Spain. Consistent with the observation of others, most Sphagnum (moss) species alkanes maximized at C23, whereas the other plants maximized at higher molecular weight (C27 to C31). We show for the first time that plants other than seagrass and Sphagnum moss contain n-alkan-2-ones. Almost all the species analysed showed an n-alkan-2-one distribution between C21 and C31 with an odd/even predominance, maximizing at C27 or C29, except ferns, which maximized at lower molecular weight (C21-C23). We also observed that microbial degradation can be a major contributor to the n-alkan-2-one distribution in sediments as opposed to a direct input of ketones from plants. 相似文献
86.
87.
We studied how features of thermal resources affect the patterns of activity of predator (Callopistes maculatus) and its prey (Gyriosomus batesi and Gyriosomus subrugatus) during the phenomenon of the Flowering Desert in Chile. We predict that restrictions or variations in temperature affect mainly the activity of insects, and that this variation in the activity of insects affects the patterns of activity of the predator. The daily activity of the three species was bimodal, but both prey species disappear when temperatures exceed 40 °C. According to our results, the prey are thermoconformers to air and substrate temperature, whereas the predator is a thermoregulator to environmental conditions by their independence of air and substrate temperature. 相似文献
88.
Leonardo Campos Fernando Berrios Brenda B. Hermosillo-Nú?ez Marco Ortiz 《海洋学报(英文版)》2022,41(12):152-155
We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta, Chile. This finding indicates an extension of the distribution limit of 500 km with respect to the last observation made in 2007 in Isla Grande de Atacama. A total of 121 specimens of O. penicillatus were recorded at depths of between 8 m and 24 m. They were associated with rocky substrate and with different species of barnacles, sponges and bryozoans. The presence of O. penicillatus expands the knowledge of the benthic biodiversity of the region, and the development of studies on its ecological importance will be promoted. 相似文献
89.
Juana Vegas Blanca Ruiz‐Zapata José E. Ortiz Luis Galán Trinidad Torres Ángel García‐Cortés María J. Gil‐García Alfredo Pérez‐González José L. Gallardo‐Millán 《第四纪科学杂志》2010,25(7):1051-1062
Geochemical (element analysis, molecular analysis of organic compounds), physical, palynological, mineralogical and sedimentary facies analysis were performed to characterise the sedimentary record in Fuentillejo maar‐lake in the Central Spanish Volcanic Field of Campo de Calatrava, in order to reconstruct the palaeoenvironmental and palaeoclimatic processes which controlled vegetation patterns and deposition of different sedimentary facies. The upper 20 m of core FUENT‐1 show variations in clastic input, water chemistry, vegetation and organic fraction sources in the lake throughout the Late Pleistocene and Holocene. The temporal framework provided by 14C accelerator mass spectrometry dating allows assigning the sequence to the last 50 cal. ka BP. Arid phases identified in the FUENT‐1 sequence are correlated to Heinrich events (HE) and to stadials of the Dansgaard/Oeschger (D/O) cycles. Siliciclastic facies with high magnetic susceptibility values, high Juniperus pollen content, a low Paq index (aquatic macrophysics proxy index), a decrease in the relative percentage of the n‐C27 and an increase in the n‐C31 alkanes are indicative of arid and colder climatic events related to HE 2, HE 1 and the Younger Dryas (YD). Similar short cold and arid phases during the Holocene were identified at 9.2–8.6, 7.5–7 and 5.5–5 cal. ka BP. In dolomite–mud facies, the pollen data show an increase in the herbs component, mainly – Chenopodiaceae, Artemisia and Ephedra – steppe taxa; a low Paq index, a decrease in the relative percentage of the n‐C27 alkane and an increase in the n‐C31 alkane are also observed. This facies was probably the result of lower lake levels and more saline–alkaline conditions, which can be interpreted as linked to arid–warm periods. These warm and arid phases were more frequent during Marine Isotope Stage (MIS) 3 and the interstadials of MIS 2. HE 4, HE 2, HE 1 and the YD in core FUENT‐1 were immediately followed by increases of warm steppe pollen assemblages that document rapid warming similar to the D/O cycles but do not imply increasing humidity in the area. Fuentillejo hydrology is controlled by changes in the atmospheric and oceanic systems that operated on the North Atlantic region at millennial scale during the last 50 cal. ka BP. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
90.
We present a further investigation of the periodogram resulting from the photometric data by Rodríguez et al. (1997) for comet
C/1995 O1 Hale–Bopp and interpret that the main period in the data is 11.23 ± 0.01 h, but not 7.19 days. The latter is now
attributed to an alias of the 11.23-h period. Assuming that the periodicity observed in the photometry is the solar day, the
11.23-h period is consistent with estimates of the sidereal rotation period by Farnham et al. (1998), and Jorda et al. (1997–1999)
provided that the obliquity of the comet‘s equatorial plane to its orbital plane is larger than 75° and 80°, respectively.
This result is in agreement with estimates of the obliquity by Sekanina (1997–1999) and Jorda et al. (1998). A weaker periodic
signal in the light curve could be 5.48 ± 0.01 h, but we suggest that this is an alias of a 3.25 ± 0.01 h period of unknown
origin.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献