全文获取类型
收费全文 | 332篇 |
免费 | 0篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 4篇 |
环保管理 | 8篇 |
综合类 | 197篇 |
基础理论 | 36篇 |
污染及防治 | 64篇 |
评价与监测 | 8篇 |
社会与环境 | 6篇 |
出版年
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1992年 | 4篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1976年 | 3篇 |
1969年 | 3篇 |
1967年 | 5篇 |
1966年 | 10篇 |
1965年 | 4篇 |
1964年 | 10篇 |
1963年 | 9篇 |
1962年 | 8篇 |
1961年 | 10篇 |
1960年 | 4篇 |
1959年 | 4篇 |
1958年 | 7篇 |
1957年 | 7篇 |
1956年 | 9篇 |
1955年 | 4篇 |
1954年 | 7篇 |
1953年 | 6篇 |
1952年 | 4篇 |
1951年 | 3篇 |
1947年 | 3篇 |
1943年 | 3篇 |
1939年 | 3篇 |
1933年 | 2篇 |
1932年 | 2篇 |
1931年 | 3篇 |
1930年 | 2篇 |
1928年 | 2篇 |
1926年 | 3篇 |
1925年 | 3篇 |
1922年 | 2篇 |
1917年 | 2篇 |
1914年 | 5篇 |
1913年 | 3篇 |
排序方式: 共有332条查询结果,搜索用时 437 毫秒
171.
172.
173.
The hydrochemistry of forest springs was investigated in the Fichtelgebirge, a region in NE Bavaria (F.R.G.) which is strongly affected by forest decline. Data were collected from 165 springs (Tables 1–5). Water chemistry is characterized by high concentrations of nitrate, sulfate and aluminium and is influenced by forest decline, liming and soil type of the catchment. Model calculations show maximal N-outputs of 40 kg nitrate-N/ha*a indicating N-saturation in some forest ecosystems of the Fichtelgebirge. N-saturated ecosystems without buffercapacity for Nitrogen will release all further N-inputs as NO3 to the aquatic ecosystem. 相似文献
174.
175.
176.
V. C. Hammen J. C. Biesmeijer R. Bommarco E. Budrys T. R. Christensen S. Fronzek R. Grabaum P. Jaksic S. Klotz P. Kramarz G. Kröel-Dulay I. Kühn M. Mirtl M. Moora T. Petanidou J. Pino S. G. Potts A. Rortais C. H. Schulze I. Steffan-Dewenter J. Stout H. Szentgyörgyi M. Vighi A. Vujic C. Westphal T. Wolf G. Zavala M. Zobel J. Settele W. E. Kunin 《Environmental monitoring and assessment》2010,164(1-4):337-348
The field site network (FSN) plays a central role in conducting joint research within all Assessing Large-scale Risks for biodiversity with tested Methods (ALARM) modules and provides a mechanism for integrating research on different topics in ALARM on the same site for measuring multiple impacts on biodiversity. The network covers most European climates and biogeographic regions, from Mediterranean through central European and boreal to subarctic. The project links databases with the European-wide field site network FSN, including geographic information system (GIS)-based information to characterise the test location for ALARM researchers for joint on-site research. Maps are provided in a standardised way and merged with other site-specific information. The application of GIS for these field sites and the information management promotes the use of the FSN for research and to disseminate the results. We conclude that ALARM FSN sites together with other research sites in Europe jointly could be used as a future backbone for research proposals. 相似文献
177.
178.
Oelmann Y Kreutziger Y Temperton VM Buchmann N Roscher C Schumacher J Schulze ED Weisser WW Wilcke W 《Journal of environmental quality》2007,36(2):396-407
Previous research has shown that plant diversity influences N and P cycles. However, the effect of plant diversity on complete ecosystem N and P budgets has not yet been assessed. For 20 plots of artificially established grassland mixtures differing in plant diversity, we determined N and P inputs by bulk and dry deposition and N and P losses by mowing (and subsequent removal of the biomass) and leaching from April 2003 to March 2004. Total deposition of N and P was 2.3 +/- 0.1 and 0.2 +/- 0.01 g m(-2) yr(-1), respectively. Mowing was the main N and P loss. The net N and P budgets were negative (-6.3 +/- 1.1 g N and -1.9 +/- 0.2 g P m(-2) yr(-1)). For N, this included a conservative estimate of atmospheric N(2) fixation. Nitrogen losses as N(2)O were expected to be small at our study site (<0.05 g m(-2) yr(-1)). Legumes increased the removal of N with the harvest and decreased leaching of NH(4)-N and dissolved organic nitrogen (DON) from the canopy. Reduced roughness of grass-containing mixtures decreased dry deposition of N and P. Total dissolved P and NO(3)-N leaching from the canopy increased in the presence of grasses attributable to the decreased N and P demand of grass-containing mixtures. Species richness did not have an effect on any of the studied fluxes. Our results demonstrate that the N and P fluxes in managed grassland are modified by the presence or absence of particular functional plant groups and are mainly driven by the management. 相似文献
179.
A. S. Prokushkin A. A. Knorre A. V. Kirdyanov E.-D. Schulze 《Russian Journal of Ecology》2006,37(4):225-232
Productivity of the moss cover and necromass accumulation in the litter of a sphagnum larch forest have been estimated on the basis of tree age. It has been shown that the total carbon stock in the litter of a 100-year-old stand, including organic matter not destroyed by fire, exceeds the corresponding value for the tree stand itself by more than an order of magnitude. The accumulation of organic matter on the soil surface inhibits the growth of larch. In particular, this factor impairs hydrothermal conditions in the soil and causes a rise of the permafrost table; as a consequence, lower layers of the root system die off. 相似文献
180.
Ina Fickelscher Heike Starke Eberhard Schulze Günther Ernst Nadezda Kosyakova Hasmik Mkrtchyan Kay MacDermont Neil Sebire Thomas Liehr 《黑龙江环境通报》2007,27(8):783-785
A prenatally ascertained case with a de novo small supernumerary marker chromosome (sSMC) derived from chromosome 1 is reported. Due to a fetal heart defect the parents decided in favour of an induced abortion. Postmortem, a molecular cytogenetic study on eleven formalin fixed, paraffin-embedded tissues of the fetus was performed, to further characterize the levels of mosaicism of the sSMC(1). sSMC presence varied between 13 and 62% within different tissues of sSMC carriers. This finding is something common in sSMC carriers and could explain why up to the present no clinical correlations for sSMC mosaicism and clinical outcome in the corresponding carriers could be established. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献