全文获取类型
收费全文 | 72篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 12篇 |
地球物理 | 17篇 |
地质学 | 25篇 |
海洋学 | 6篇 |
天文学 | 3篇 |
自然地理 | 8篇 |
出版年
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 15 毫秒
61.
Mark Wise 《Geoforum》2007,38(1):171-189
The political salience of demands from minority and regional groups for greater language rights increases across Europe. To draw more geographical attention to a particular aspect of these developments, this article identifies the main generic problems of converting demands for ‘linguistic rights’ into applied language policies. It does this by first outlining how the historic process of nation-state building in Europe reduced linguistic diversity, but has not eliminated language demands emanating from regional minorities. It then analyses how the concept of ‘linguistic rights’, as a part of human rights in general, has been developing within the United Nations and bodies including the Council of Europe and the European Union. Having outlined the political-legal frameworks within which minority language rights are pursued, the article then discusses the major difficulties of putting them into practice in particular places and spaces. They can be summarised as: the weakness of relevant international agreements; the dominance of state sovereignty in determining language policies; the limited public support for minority language rights; the difficulties of defining minority languages and delimiting the geographical spaces they occupy; the challenges posed by the growing geographical mobility of populations; and the problem of balancing collective and individual rights. Two fundamental issues linking these different problems are identified. First, there are problems of definition: what constitutes a ‘minority’ or ‘regional’ language and within what geographical space(s) is such a language spoken? This spatial dimension underlies a second fundamental problem, namely that of resolving conflicts between individual personality rights and collective territorial rights in increasing hybrid geolinguistic situations created by the growing geographical mobility of populations. Sociolinguists study these issues, but usually treat these essential spatial dimensions in a superficial fashion. Thus, there is an opportunity for geographers to develop more sophisticated geolinguistic analyses as a contribution to this interdisciplinary field. 相似文献
62.
Michael A. Wise 《Mineralogy and Petrology》2009,96(3-4):213-220
Alpine-type fissure vein mineralization in the Hiddenite area of western North Carolina, USA consists mostly of quartz, but locally contains Cr-bearing beryl (emerald) or Cr-bearing spodumene (hiddenite). These gem minerals occur in mineral-lined cavities and may be accompanied by euhedral crystals of quartz, calcite, muscovite, rutile, albite, pyrite, siderite and dolomite. Chabazite-Ca occurs as a late stage phase in spodumene-bearing veins, but is absent in emerald-bearing veins. Chabazite-Ca occurs as simple penetrating twins of pseudocubic rhombohedra and as the lens-shaped variety, phacolite. Chabazite-Ca from Hiddenite contains minor amounts of Na, Mg, Fe and K. Phacolitic chabazite-Ca shows Fe-enriched but Mg-depleted cores relative to the rims. Chemical zoning is absent in rhombohedral chabazite. The Hiddenite chabazite apparently precipitated under low temperature (< 250°C) and low pressure (< 2 kbar) conditions during the waning stages of crystallization of an alkaline hydrothermal fluid. 相似文献
63.
Trudi A. Semeniuk Matthew E. Wise Scot T. Martin Lynn M. Russell Peter R. Buseck 《Journal of Atmospheric Chemistry》2007,56(3):259-273
We used both a conventional transmission electron microscope and an environmental transmission electron microscope (ETEM)
to determine morphology, composition, and water uptake of 80 individual aerosol particles collected from the young smoke of
flaming and smoldering fires during SAFARI-2000, a comprehensive air quality campaign in southern Africa. Six representative
carbonaceous particle types are described, including soot, tar balls, and heterogeneously internally mixed particles containing
C with S-, K-, Mg- or Na-rich inorganic phases. The hygroscopic behavior of these particles over the range 0–100% relative
humidity (RH) was studied in detail. Soot and tar balls did not take up water, whereas the mixed organic–inorganic particles
took up water between 55 and 100% RH, the exact value depending on the composition of their water-soluble phases. The inorganic
phase appeared to determine the hygroscopic properties of all mixed organic–inorganic particles. Thus, incorporation of inorganic
plant material or reactions with inorganic atmospheric components can dramatically alter the hygroscopic properties of carbonaceous
particles in smoke plumes. The fraction of these mixed organic–inorganic particles plausibly increases with time, which will
modulate the effects of smoke on radiative budgets. 相似文献
64.
PIERRE EXERTIER JOËLLE NICOLAS PHILIPPE BERIO DAVID COULOT PASCAL BONNEFOND OLIVIER LAURAIN 《Marine Geodesy》2013,36(1-2):333-340
The French Transportable Laser Ranging System (FTLRS), a highly transportable Satellite Laser Ranging (SLR) instrument, was set up in Corsica (from January to September 2002) for participating to the JASON-1 altimeter verification phase. In addition to the tracking of oceanographic satellite missions and in order to perform an accurate positioning, the FTLRS also acquired laser ranging data on geodetic satellites, STARLETTE and STELLA essentially. The paper describes the analysis strategy mainly based on the use of a short-arc orbit technique to compute accurate 1 cm local orbits, and then the geocentric positioning (2–3 mm relative to GPS). Finally, we established the JASON-1 absolute calibration value, based on 9 SLR short-arcs (between cycles 1 and 26), at 108.2 ± 8.7 mm; the 10-day repeatability is of 26.1 mm showing that a great accuracy has been reached. 相似文献
65.
Donald F. Charles Michael W. Binford Edward T. Furlong Ronald A. Hites Myron J. Mitchell Stephen A. Norton Frank Oldfield Michael J. Paterson John P. Smol Allen J. Uutala Jeffrey R. White Donald R. Whitehead Robert J. Wise 《Journal of Paleolimnology》1990,3(3):195-241
Paleoecological analysis of the sediment record of 12 Adirondack lakes reveals that the 8 clearwater lakes with current pH < 5.5 and alkalinity < 10 eq l-1 have acidified recently. The onset of this acidification occurred between 1920 and 1970. Loss of alkalinity, based on quanitative analysis of diatom assemblages, ranged from 2 to 35 eq l-1. The acidification trends are substantiated by several lines of evidence including stratigraphies of diatom, chrysophyte, chironomid, and cladoceran remains, Ca:Ti and Mn:Ti ratios, sequentially extracted forms of Al, and historical fish data. Acidification trends appear to be continuing in some lakes, despite reductions in atmospheric sulfur loading that began in the early 1970s. The primary cause of the acidification trend is clearly increased atmospheric deposition of strong acids derived from the combustion of fossil fuels. Natural processes and watershed disturbances cannot account for the changes in water chemistry that have occurred, but they may play a role. Sediment core profiles of Pb, Cu, V, Zn, S, polycyclic aromatic hydrocarbons, magnetic particles, and coal and oil soot provide a clear record of increased atmospheric input of materials associated with the combustion of fossil fuels beginning in the late 1800s and early 1900s. The primary evidence for acidification occurs after that period, and the pattern of water chemistry response to increased acid inputs is consistent with current understanding of lake-watershed acidification processes.This is the second of a series of papers to be published by this journal which is a contribution of the Paleoecological Investigation of Recent Lake Acidification (PIRLA) project. Drs. D.F. Charles and D.R. Whitehead are guest editors for this series. 相似文献
66.
67.
Michael C. Brooks William R. Wise Michael D. Annable 《Ground Water Monitoring & Remediation》1999,19(2):105-113
Two types of gas-phase flow patterns have been discussed and observed in the in situ air sparging (ISAS) literature: bubble flow and air channels. A critical factor affecting the flow pattern at a given location is the grain size of the porous medium. Visualization experiments reported in the literature indicate that a change in the flow pattern occurs around 1 to 2 mm grain diameters, with air channels occurring below the transition size and bubbles above. Analysis of capillary and buoyancy forces suggests that for a given gas-liquid-solid system, there is a critical size that dictates the dominant force, and the dominant force will in turn dictate the flow pattern. The dominant forces, and consequently the two-phase flow patterns, were characterized using a Bond number modified with the porous media aspect ratio (pore throat to pore body ratio). Laboratory experiments were conducted to observe flow patterns as a function of porous media size and air flow rate. The experimental results and the modified Bond number analysis support the relationship of flow patterns to grain size reported in the literature. 相似文献
68.
69.
Tidal current power is one of the promising and reliable renewable energies with the advantage of continuous and predictable resource. It can make stable electricity regardless of weather conditions or seasons all year around. The required technologies for tidal current power in the ocean have been developed for years and now recognized that it could be commercialized after intensive field tests and successful demonstrations. There are several tidal farm development projects in the world, such as the MeyGen project in UK with its commercialization at hand. However, various research subjects in the tidal current energy field are seeking improvements and industrialization of tidal current power in terms of economy and technical reliability. This paper introduces the resource assessment procedure of tidal energy that has been applied in Korea coastal regions. The key research subjects for tidal current power together with the interaction effect of multi-arrangement is described. Also, this paper is to introduce the research output of each subject such as turbine design, experimental validation, turbine interaction and wake, multi-array module, FSI (fluid-structure interaction), and duct application. 相似文献
70.
Stephen Wise 《Transactions in GIS》2002,6(3):327-337
Data capture from paper maps remain a slow and costly part of many Geographic Information System projects. In this paper a simple method is described which makes use of the facilities of desktop graphics software to capture raster data from scanned thematic maps. The first stage is to use the flood fill tool to identify the regions of the map that represent the data values and set them to a separate colour for each thematic category. This edited image is then imported into a GIS, where a specially written majority filter is used to classify any remaining pixels to produce a raster GIS layer. The technique is tested on samples from three maps, giving accuracy levels of over 90% in all cases when compared with digitising the same maps by hand. The technique could be useful for situations where a rapid and simple means of data capture is needed and could be developed further by drawing on techniques for contextual classification rather than relying on a general purpose flood fill algorithm. 相似文献