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101.
Lawrence Livermore National Laboratory (LLNL) uses a cost-effective sampling (CES) methodology to evaluate and review ground water contaminant data and optimize the site's ground water monitoring plan. The CES methodology is part of LLNL's regulatory approved compliance monitoring plan (Lamarre et al. 1996). It allows LLNL to adjust the ground water sampling plan every quarter in response to changing conditions at the site. Since the use of the CES methodology has been approved by the appropriate regulatory agencies, such adjustments do not need additional regulatory approval. This permits LLNL to respond more quickly to changing conditions. The CES methodology bases the sampling frequency for each location on trend, variability, and magnitude statistics describing the contaminants at that location, and on the input of the technical staff (hydrologists, chemists, statisticians, and project leaders). After initial setup is complete, each application of CES takes only a few days for as many as 400 wells. Effective use of the CES methodology requires sufficient data, an understanding of contaminant transport at the site, and an adequate number of monitoring wells downgradient of the contamination. The initial implementation of CES at LLNL in 1992 produced a 40% reduction in the required number of annual routine ground water samples at LLNL. This has saved LLNL $390,000 annually in sampling, analysis, and data management costs. 相似文献
102.
Identification and characterization of lipolytic and proteolytic bacteria isolated from marine sediments 总被引:1,自引:0,他引:1
Lipolytic and proteolytic bacteria were isolated from sediments at two sampling stations in the New York Bight Apex and one sampling station each in Sandy Hook Bay and Great Bay, New Jersey. The stations in the Bight Apex and Sandy Hook Bay have received industrial wastes and sewage for several decades, while Great Bay has received little of such materials. Proteolytic counts were 2–4 times higher and lipolytic counts generally 4 times higher in the polluted areas. Of the isolates taken from casein and lipid plates, 76% were Gram-negative rods; 80% of the latter were identified as Vibrio and Pseudomonas. The vibrios comprised more than 60% of the isolates from Station 4 (Great Bay) and Station 1 (Bight Apex), and were tested for their ability to break down casein, lipid, starch, and chitin. From Station 1, 75% of the Vibrio were active in degrading one or more substrates in addition to the substrate of the initial isolation medium; from Station 4, 52% of the Vibrio were active. 相似文献
103.
Shear Wave Splitting and Mantle Anisotropy: Measurements, Interpretations, and New Directions 总被引:5,自引:1,他引:4
Measurements of the splitting or birefringence of seismic shear waves that have passed through the Earth’s mantle yield constraints on the strength and geometry of elastic anisotropy in various regions, including the upper mantle, the transition zone, and the D″ layer. In turn, information about the occurrence and character of seismic anisotropy allows us to make inferences about the style and geometry of mantle flow because anisotropy is a direct consequence of deformational processes. While shear wave splitting is an unambiguous indicator of anisotropy, the fact that it is typically a near-vertical path-integrated measurement means that splitting measurements generally lack depth resolution. Because shear wave splitting yields some of the most direct constraints we have on mantle flow, however, understanding how to make and interpret splitting measurements correctly and how to relate them properly to mantle flow is of paramount importance to the study of mantle dynamics. In this paper, we review the state of the art and recent developments in the measurement and interpretation of shear wave splitting—including new measurement methodologies and forward and inverse modeling techniques,—provide an overview of data sets from different tectonic settings, show how they help us relate mantle flow to surface tectonics, and discuss new directions that should help to advance the shear wave splitting field. 相似文献
104.
The red king crab Paralithodes camtschaticus was introduced to the Barents Sea from the North Pacific in the 1960s. A previous study concluded that it may be indirectly responsible for increased transmission of Trypanosoma murmanense to cod Gadus morhua in the southern Barents Sea by promoting an increase in the population of the leech vector Johanssonia arctica. Eleven species of fish, totalling 681 individuals, caught in October 2002 along the coast of Finnmark, were examined for trypanosome infections. The aims were to investigate changes in levels of infection in cod since 1999–2001, and to extend the sampling to other fish species. Relatively high infection levels were found in cod, haddock Melanogrammus aeglefinus and long rough dab Hippoglossoides platessoides, while other species were lightly infected or uninfected. In cod, no significant geographical differences in levels of infection were found, but haddock were significantly more heavily infected in western Finnmark. 相似文献
105.
A New LA‐ICP‐MS Method for Ti in Quartz: Implications and Application to High Pressure Rutile‐Quartz Veins from the Czech Erzgebirge
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Alicia M. Cruz‐Uribe Regina Mertz‐Kraus Thomas Zack Maureen D. Feineman Glenn Woods Dorrit E. Jacob 《Geostandards and Geoanalytical Research》2017,41(1):29-40
Experimental determination of the pressure and temperature controls on Ti solubility in quartz provides a calibration of the Ti‐in‐quartz (TitaniQ) geothermometer applicable to geological conditions up to ~ 20 kbar. We present a new method for determining 48Ti mass fractions in quartz by LA‐ICP‐MS at the 1 μg g?1 level, relevant to quartz in HP‐LT terranes. We suggest that natural quartz such as the low‐CL rims of the Bishop Tuff quartz (determined by EPMA; 41 ± 2 μg g?1 Ti, 2s) is more suitable than NIST reference glasses as a reference material for low Ti mass fractions because matrix effects are limited, Ca isobaric interferences are avoided, and polyatomic interferences at mass 48 are insignificant, thus allowing for the use of 48Ti as a normalising mass. Average titanium mass fraction from thirty‐three analyses of low temperature quartz from the Czech Erzgebirge is 0.9 ± 0.2 μg g?1 (2s) using 48Ti as a normalising mass and Bishop Tuff quartz rims as a reference material. The 2s average analytical uncertainty for individual analyses of 48Ti is 8% for 50 μm spots and 7% for 100 μm spots, which offers much greater accuracy than the 21–41% uncertainty (2s) incurred from using 49Ti as an analyte. 相似文献
106.
107.
Maureen G. Reed 《社会与自然资源》2014,27(11):1223-1225
108.
Michael A. Nwachukwu Huan Feng Jude Alinnor Maureen Nwachukwu 《Environmental Earth Sciences》2012,65(3):765-774
Heavy metal enrichment parity in sandy and shaly mechanic village (MV) soils was studied in order to explain the technical
and economic imperatives of setting an environmentally friendly MV on either soil. Okigwe (shaly) and Nekede (sandy) mechanic
village soils in the Imo River basin Nigeria were tested and compared. Spectroscopic analysis of the soil samples collected
from three surface layers (L), where L1: 0–10 cm; L2: 10–20 cm and L3: 90–100 cm shows that Pb > Cu > Mn in the Okigwe MV,
and Mn > Pb > Cu in the Nekede MV. Mean concentration of metals (mg kg−1) in Okigwe MV are Fe: 51,291 ± 18,148, Ni: 22 ± 4, Cd: 20 ± 3, Pb: 500 ± 513, Cu: 616 ± 369, Cr: 16 ± 9, and Mn: 378 ± 207.
Similarly, Nekede MV has 22,101 ± 7,273 of Fe; 8 ± 0.8 of Ni; 11 ± 4 of Cd; 320 ± 122 of Pb; 265 ± 145 of Cu; 11 ± 2 of Cr;
and 350 ± 191 of Mn. Pollution factor (Pf): Okigwe MV has 0.77, and Nekede has 0.68. Pollution degree: Okigwe MV is greater
in L1 and L2, while Nekede is greater in L3, with greater potentials for Pb, and Mn mobility than the Okigwe. Both have similar
trends of metal distribution, and significant correlation with their background values. Low clay-silt content in Nekede MV
soil suggests low sorption capacity, whereas the high clay-silt content (47–64%) of the Okigwe soil suggests lower bioavailability.
Infiltration basin is not recommended in a MV on sandy soil if water table is near surface. In such case, the MV must be moved
to a location where water table is >37 m, or have clay-shale material transported to the site to form impervious layer base
for detention basin. For groundwater safety and sustainability, shaly soils are most recommended for MVs so that detention
basin could be economically used for storm water treatment. 相似文献
109.
In 2011, a large repository of resting cysts of the toxic dinoflagellate Alexandrium catenella was discovered in the sediments of the Onapua/Opua inlet located off Tory Channel, Queen Charlotte Sound. The inlet is a potential source of infection for other areas, such as the major mussel-growing areas of Port Underwood and Pelorus Sound. This study aimed to establish whether the dinoflagellate was a new arrival in the Sounds or had existed unnoticed in this isolated embayment for some time. Alexandrium catenella cysts were identified to a depth of 20–21?cm within the sediment cores, corresponding to a date estimated by radioisotope (210Pb and 137Cs) and Pinus radiata pollen distribution to at least the mid 1970s. Over this time span, resident populations of A. catenella have not become established beyond the confines of Queen Charlotte Sound, suggesting it does not pose an imminent threat of doing so unless increasingly intense and prolonged blooms result in more widespread cyst dispersal. 相似文献
110.
Two measures of microbial activity were used to characterise a variety of sediment habitats in three intertidal inlets in the Nelson region, South Island, New Zealand. Rates of microbial mineralisation potential and epibenthic microalgal production were compared with sediment textures, concentrations of photosynthetic pigments, ATP concentrations, and organic and inorganic nutrients. Baseline ranges for these parameters were established for relatively undisturbed estuarine sites for assessing future environmental deterioration and for comparison with sites affected by organic enrichment. Sediment mineralisation rates were increased more than 1000‐fold by enrichment from a fruit processing plant and microalgal production was enhanced by more than 50‐fold at a site exposed to slaughterhouse wastes. The remaining variables, although often strongly correlated with activity measurements, were not as sensitive as measures of enrichment. Sediment microbial activity measurements are proposed as a means of detecting changes in nutrient status of estuarine environments. 相似文献