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401.
F. G. Riet Saprtza N. Lopez‐Villalobos D. D. S. Mackenzie P. J. Duignan A. MacGibbon B. L. Chilvers 《新西兰海洋与淡水研究杂志》2013,47(4):997-1006
Abstract The milk composition of New Zealand sea lion, Phocarctos hookeri, was determined using standard analytical methods, a MilkoScan? FT 120 and an accelerated solvent extractor (ASE) for fat concentration. The results for fat, protein and total solid concentrations between the different analytical methods were assessed using different measures of statistical fitness including coefficient of determination, concordance correlation coefficient, mean prediction error, and intraclass correlation coefficient. The repeatability and reliability of the results obtained with the calibrated MilkoScan? FT 120 were comparable with those obtained using standard methods, the Roese‐Gottlieb method for fat, Kjeldahl method for protein and gravimetric method for total solids. The MilkoScan? FT 120s are fast and cost‐effective and are widely used in dairy laboratories around the world, which should make them readily accessible to ecologists/biologists studying the milk composition of non‐domestic animals. 相似文献
402.
香港能见度、大气悬浮粒子浓度与气象条件的关系 总被引:10,自引:2,他引:8
利用2005年赤角能见度及东涌悬浮粒子(PM2.5)浓度的每小时数据,发现PM2.5 浓度与能见度(撇除雨雾及相对湿度≥95%的个例)呈倒数关系,相关系数约为0.8.此外,出现低能见度(能见度低于8 km,而雨雾及相对湿度≥95%的个例不计)的每月总时数与月平均PM2.5浓度都呈现相类似的季节趋势,即冬季较高,夏季较低.利用HYSPLIT作反轨迹图分析显示这现象跟影响香港的空气来源有关.来自内陆的轨迹中,出现低能见度的日平均时数及日平均PM2.5的浓度,分别远高于来自海洋的轨迹.文中还分析了一个有热带气旋接近本港的个例,论证气象条件对能见度及PM2.5浓度的重要性. 相似文献
403.
The objective of this research is to investigate spatial and temporal variation in the transport of phosphate by grain size fractions of suspended sediment in two Lake Erie tributaries. A sediment-phosphate transport model is proposed to evaluate and quantify the kinetic control of dissolved phosphate by fluvial sediment. A first-order assessment of the sediment-phosphate export from Big Otter Creek and Big Creek to Lake Erie is presented. Output from this model was calculated using historical discharge and sediment data collected by Environment Canada in combination with adsorption coefficients derived from laboratory experiments for a range of sediment grain size fractions. Results of these calculations provide a quantitative interpretation of the influence of suspended sediment on phosphate dynamics in tributaries and the potential impact on water quality of receiving waters. 相似文献
404.
Samples of surficial fine-grained laminae (SFGL) were collected in three south-western Ontario rivers. Each sediment sample was subjected to a sequential extraction procedure designed to partition particulate metals (Cd, Pb, Cu, Zn) into five operationally defined fractions: (1) exchangeable; (2) bound to carbonates; (3) bound to Fe-Mn oxides; (4) bound to organic matter; and (5) residual. Particulate phosphus was sequentially extracted from the sediment samples into three fractions: (1) non-apatite inorganic P; (2) apatite P; and (3) organic P. The major accumulate phases of trace metals in SFGL are carbonates, Fe-Mn oxides and organic matter. The content of NAIP in SFGL ranged from 17 to 38% of total particulate P. Compared with suspended and bed sediments, levels of P and trace metals in SFGL were lower at the study sites. A conceptual overview of physical, chemical and biological processes influencing formation of SFGL and the potential role of this fine-grained sediment for contaminant transport in fluvial systems is presented. 相似文献
405.
Jean-Maurice Cases 《Comptes Rendus Geoscience》2002,334(9):585-596
This introductory paper aims at presenting the series of articles in this special issue of Comptes Rendus Geoscience devoted to the study and use of natural minerals. The research methodology that can be applied to the investigation of surface phenomena related to adsorption, exchange and retention onto the surface of natural minerals and divided solids is presented. A special focus is given to the retention of surfactant molecules, in view of their considerable importance in numerous industrial fields, such as, for instance, mineral flotation and enhanced oil recovery. Throughout this introductory paper, the relevance of this research approach to the field of geosciences is stressed by listing various applications where it can provide conclusive answers, especially for environmentally related issues. To cite this article: J.-M. Cases, C. R. Geoscience 334 (2002) 585–596. 相似文献
406.
Jean-Maurice Cases Jerzy Mielczarski Ella Mielczarska Laurent J. Michot Frédéric Villiéras Fabien Thomas 《Comptes Rendus Geoscience》2002,334(9):675-688
The adsorption of surfactants from aqueous solution is a phenomenon of major importance in applications ranging from ore flotation and paint technology to enhanced oil recovery. As this paper will illustrate, the process is very complex and of high scientific interest; its results can be extended to the retention of organic compounds (humic and fulvic acids, pollutants...) on solids in the biosphere. For a good understanding of the mechanisms involved in surfactants adsorption at the hydrophilic solid–aqueous solution interface, thermodynamic models have to take into account: (i) the physical chemistry of the surfactant in aqueous solution for choosing the appropriate reference phase, (ii) the surface heterogeneity of the adsorbing solid, (iii) the intensity of normal adsorbate–adsorbent bonds responsible for adsorption, (iv) the intensity of lateral bonds that favour the formation of surface aggregates through cooperative process and finally, (v) suitable theoretical models to describe adsorption phenomena. Once this has been achieved, two systems can be discussed: systems characterised by strong normal adsorbate–adsorbent bonds, currently used in ore flotation, which lead, in the case of heterogeneous surfaces, to the formation of lamellar aggregates at monolayer concentration and bilayer formation for higher concentrations. Systems characterised by weak normal adsorbate–adsorbent bonds, currently used in enhanced oil recovery and hydrocarbon (bio)remediation, which correspond to: (i) formation of globular micelles at the solid surface near the CMC when the temperature is higher than the Krafft point, (ii) formation of bilayered lamellar aggregates in the opposite case, (iii) three-dimensional condensation on substrate (T<TKrafft) if the ionic surfactant interacts with cations in the bulk. To cite this article: J.-M. Cases et al., C. R. Geoscience 334 (2002) 675–688. 相似文献
407.
Groundwater quality in the Niva River basin, Chittoor district, Andhra Pradesh, India 总被引:2,自引:0,他引:2
This study was made to assess the groundwater quality in relation to agricultural and domestic uses in a part of the Peninsular
Archean granite and gneissic complex of India. Water samples were collected from the existing wells in the Niva River basin,
Chittoor district, Andhra Pradesh, India and analysed for major ions. The analytical data, processed and interpreted acoording
to the WHO standards, reveal that, in general, the groundwater is suitable for both agricultural and domestic uses, exept
in a few locations. High concentration of nitrates were observed in some of the wells (both agricultural and domestic) that
are affected by the impact of industrial effluents. Multiple regression analysis was performed and used as a positive predictive
tool in understanding the chemistry of the groundwater.
Received: 2 May 1996 / Accepted: 14 October 1996 相似文献
408.
Suspended sediment transport effectiveness was examined near the mouths of three large impounded rivers (Rio Grande, Brazos,
and Pearl Rivers) in differing precipitation regimes in the U.S. Gulf Coastal Plain. Magnitude and frequency analysis of suspended
sediment transport was performed by examining the effectiveness of both discharge and time in transporting suspended sediment.
Bivariate plots of discharge with infrequent values of silt/clay and sand provide an insight into the relative proportion
of coarse-versus fine-grained sediment transport for the three rivers. Despite the aridity of the Rio Grande and Brazos drainage
basins, which is often associated with infrequent or episodic transport of sediment, the duration of the effective discharge
is similar to humid basins described in the literature. The majority of sediment transport occurs during the moderate discharge
events, having a duration of 2.4%, 1.5%, and 4.4% for the Rio Grande, Brazos, and Pearl Rivers, respectively. This may be
due to the influence of scale or the influence of upstream dams and reservoirs on discharge and sediment transport. Findings
from this research suggest that magnitude and frequency analysis of discharge and suspended sediment near the mouths of large
rivers may provide a useful framework for understanding the timing and delivery of riverine sediments to the nearshore coastal
environment from rivers draining a range of geologic and climatic settings.
Received: 6 September 1996 · Accepted: 4 February 1997 相似文献
409.
WANG Xingkui LI Danxun XU Shitao Key Laboratory for Water Sediment Sciences of Ministry of Education Tsinghua University Beijing CHINA. 《国际泥沙研究》2001,16(2)
INTRODUCTIONThe planned outer ring road in Shanghai City crosses the Huangpu mver, a tribuop of the YangtzeXiver Veq near the river mouth. The sinldng method is reconunended in constIUchon of submergedcrossing-river tonnel which is 725m long and has a transversal section of M.6InX8.75m. For the design ofthe consAnction scheme, sediment dePosihon the in the excavated trench serves as an impoftaIltparameter. Physical mode exPeriments were then conducted to inveshgate the rate of sedim… 相似文献
410.