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61.
Integrating toxicology and ecology: putting the "eco" into ecotoxicology   总被引:1,自引:0,他引:1  
Environmental toxicology has been and continues to be an important discipline (e.g., single-species testing for screening purposes). However, ecological toxicology (ecotoxicology--more realism in tests, test species and exposures) is required for predicting real world effects and for site-specific assessments. Ecotoxicology and ecology have shown similar developmental patterns over time; closer cooperation between ecologists and toxicologists would benefit both disciplines. Ecology can be incorporated into toxicology either extrinsically (separately, e.g., providing information on pre-selected test species) or intrinsically (e.g., as part of test species selection)--the latter is preferable. General guidelines for acute and chronic testing and criteria for species selection differ for ecotoxicology and environmental toxicology, and are outlined. An overall framework is proposed based on ecological risk assessment (ERA), for combining ecology and toxicology (environmental and ecological) for decision-making. Increased emphasis on ecotoxicology represents a shift from reductionist to holistic approaches.  相似文献   
62.
雪生态学研究进展   总被引:14,自引:0,他引:14  
文章从雪盖与气候系统、雪盖的物理特性及其与生态学的关系、雪化学过程与养分循环、冰雪微生物、雪盖与小型动物、雪盖和植被等 6个方面综述了当前世界雪生态学研究进展,并对雪生态学近期需要研究的问题进行了讨论。总体来看,当前国际雪生态学研究存在如下发展趋势:①强调全球气候变化对雪盖的影响及其反馈作用;②注重雪和雪盖的物理特性及其生态功能;③对雪盖生态系统的养分循环过程的研究报道增加;④冰雪微生物的超微结构、生理学、生理生态学、生态学、生命史、生物化学的研究得到了较快发展;⑤雪盖小型哺乳动物的生理、生态、形态适应性研究得到更多重视;⑥有关极端环境下的植物生理生态适应性及其与雪环境梯度变化关系的研究兴趣增加;⑦过程研究、定量研究、数值模拟研究在各个方面都更加得到重视。  相似文献   
63.
In the Middle East and Africa, the Cenomanian ammonite genus Neolobites occurs, partly in great abundance, in shallow marine shelf settings. The genus includes several species but it has remained uncertain to what extent these species reflect biospecies, chronospecies or morphological variants. Based on material from Jordan and Egypt, the morphological variation of Neolobites vibrayeanus is described and discussed. From the several species of Neolobites described in the literature, only N. vibrayeanus, N. fourtaui and N. peroni appear to deserve specific separation. Sedimentological and lithological data, notably the common occurrence in strata that were possibly deposited above storm wave base, suggest that Neolobites was able to inhabit shallow marine settings. In these settings, it seems to form a distinct assemblage with the nautiloid Angulithes. Although N. vibrayeanus shows morphological variability between distinct populations, local N. vibrayeanus assemblages seem to develop morphologically stable populations that show only a little morphological overlap with those of other areas. This may be the reason for the earlier taxonomic splitting. The occurrence in habitats in which other stratigraphically significant ammonites are often missing may be the reason for the previous poor dating of Neolobites assemblages.  相似文献   
64.
中国生态系统研究网络(CERN):概况、成就和展望   总被引:3,自引:0,他引:3  
在中国科学院的支持下,中国生态系统研究网络(CERN)于1988年建立,现由代表不同生态系统的36个生态站、5个分中心和1个综合中心组成。经过10多年的努力,CERN各站和中心已按照规定的监测指标体系和操作规范,系统地开展了生态监测以及有关的研究和生态系统优化管理模式示范等方面的工作,且已取得了一系列重大成果。CERN目前已经成为我国生态学研究和人才培养的重要基地及国际生态监测与研究网络的重要组成部分。随着中国科学院知识创新工程第三期计划的启动,CERN又将进入到一个重要的发展阶段。可以预期,CERN在促进科学发展和服务社会方面都将取得更重大的成就。  相似文献   
65.
Since sewage treatment plants are most effective in Switzerland, the micro-benthic communities in receiving running waters have changed considerably. From January 1980 to September 1981 the periphyton communities in 13 Swiss streams and rivers were monthly investigated. The NH4-N concentration in these waters varied between 0.015 and 1.0 mg/l. Four typical communities of microorganisms were found:In unpolluted running waters mainly small vagile ciliates were abundant; in slightly polluted waters peritricha (in the presence of bacteria) were found; in moderatly polluted waters peritricha in combination of few hymenostomata and Sphaerotilus could grow when bacteria and some degredable organic material where present; in polluted waters the well-known Spaerotilus-community (after Liebmann) could be found.The microscopic as well as the macroscopic aspect should be considered to qualify the degree of pollution in streams and rivers.  相似文献   
66.
Louise Crabtree 《Geoforum》2006,37(4):519-535
This paper responds to challenges made by Castree [Castree, N., 2004. Environmental issues: signals in the noise? Progress in Human Geography 28 (1), 79-90] and Sneddon [Sneddon, C., 2000. ‘Sustainability’ in ecological economics, ecology and livelihoods: a review. Progress in Human Geography 24 (4), 521-549] for human geography to clarify its contribution to environmental debates and engage with recent formulations of sustainability as informed by the ‘new ecology’. This approach focuses on resilience, functional diversity, flexibility and complexity, here used to examine housing sustainability within an industrialised sub/urban context in terms of design philosophy, ownership, management bases, community engagement and funding mechanisms. This framework highlights areas of concern for enhancing the functional diversity of housing systems, echoing recent assertions that challenges for sustainability arise more from trust and power sharing issues, than from physical design and maintenance issues. It is argued that it is precisely human geography’s place-by-place consideration of power, embeddedness, scale and politics that can lend new ecology the social relevance it requires.  相似文献   
67.
Mapping and measuring the ecological embeddedness of food supply chains   总被引:1,自引:0,他引:1  
Marianne Penker 《Geoforum》2006,37(3):368-379
The status of nature in food systems is the subject of this paper, which looks into the ecological embeddedness of the Austrian food system both on the national level and in a regional case study. By a first attempt to measure and map ecological embeddedness, the author intends to contribute to the operationalisation of the embeddedness concept, which is characterised as ambivalent, fuzzy and dynamic (see e.g., [Goodman, D., 2003. The quality ‘turn’ and alternative food practices: reflections and agenda. Editorial. Journal of Rural Studies 19 (1), 1-7; Markusen, A., 1999. Fuzzy concepts, scanty evidence, policy distance: the case for rigour and policy relevance in critical regional studies. Regional Studies 33, 869-884; Hess, M., 2004. ‘Spatial’ relationships? Towards a reconceptualization of embeddedness. Progress in Human Geography 28 (2), 165-186]). The paper starts with a critical outline of the academic discourse on embeddedness in food chain studies. In the second section, general developments in the Austrian food system and their ecological implications are illustrated for the national level. Thereafter in a case study, the author tries to map and measure the ecological embeddedness of two conventional bread chains. The focus on conventional food chains provides a contrast with the growing body of embeddedness studies concentrating on alternative food chains. The author concludes that for both conventional as well as alternative food chains, the mode of ecological embeddedness or the degree of a food chain’s commitment to particular landscapes could become important factors for the maintenance, enhancement and capture of ecological value.  相似文献   
68.
Seasonal occurrence of six ostracod species (Psychrodromus olivaceus, Potamocypris villosa, Ilyocypris inermis, Candona candida, Candona neglecta, and Cypridopsis vidua) varied from May 2003 to June 2004 in three types of spring (Limnocrene, Helocrene, Rheocrene). When I. inermis was only found in the limnocrene spring each month, P. olivaceus was common in all types of springs. The other four ostracods were found in the helocrene spring in fall, winter, and spring seasons. The unweighted pair group mean averages dendrogram separated three main clusters. The first cluster includes two species (C. vidua, C. candida) while I. inermis was found in the second cluster and P. olivaceus, C. neglecta, and P. villosa were found in the third. The occurrence of P. olivaceus and C. neglecta and P. villosa and C. candida was strongly correlated to each other (r=0.750 and 0.850, respectively). The Pearson correlation analyses showed a strong negative relationship between C. neglecta and water temperature (r=−0.607), but other species did not show any significant correlation to any of the environmental variables used (P>0.05). Canonical correspondence analyses (CCA) displayed all species closer to the center of the dendrogram, indicating high levels of species tolerances to environmental variables. Thus, the first axis of the CCA diagram explained 80% of the relationship between six species and five environmental variables.  相似文献   
69.
Diatoms from the genus Achnanthidium are abundant in rivers, streams, and springs of the Appalachian Mountains. They inhabit clean and polluted waters, including those affected by acid mine drainage. The identification of Achnanthidium taxa is difficult due to their small cell size and insufficient information in the diatom floras. We studied the taxonomy and ecology of Achnanthidium in Appalachian rivers by analyzing a data set of benthic diatom samples and corresponding water chemistry data collected during several water-quality surveys from 181 sampling sites. Ten species were identified using scanning electron and light microscopy: A. alpestre (Lowe & Kociolek) Lowe & Kociolek, A. atomus (Hustedt) Monnier, Lange-Bertalot, & Ector, A. deflexum (Reimer) Kingston, A. duthii (Sreenivasa) Edlund, A. eutrophilum (Lange-Bertalot) Lange-Bertalot, A. cf. gracillimum (Meister) Lange-Bertalot, A. cf. latecephalum Kobayasi, A. minutissimum (Kützing) Czarnecki (sensu lato), A. reimeri (Camburn) comb. nov., and A. rivulare Potapova & Ponader. The distribution of common taxa in relation to water chemistry was studied by fitting non-parametric regression models (generalized additive models, GAM, and non-parametric multiplicative regression models, NPMR) to species relative abundances. Studied Achnanthidium species differed considerably in their responses to water chemistry. These results suggest that species-level identifications will lead to more accurate bioassessments.  相似文献   
70.
At three alpine locations in Switzerland adults of Drusus melanchaetes and unknown Drusinae larvae which could not be identified with existing keys were sampled. Based on DNA association with adults, we identified the unknown larvae as D. melanchaetes. To further support the association of specimens a phylogeny was estimated with the putative closest relatives of D. melanchaetesD. monticola and D. nigrescens – and five other species of Drusus (D. chrysotus, destitutus, discolor, muelleri and romanicus). A highly supported monophyletic clade groups unknown larvae and D. melanchaetes specimens from the central Alps and Austria (Vorarlberg), confirming the association.Based on morphology, larvae of D. melanchaetes key out together with D. destitutus in existing keys. D. melanchaetes is separated from the latter species by the shape of the lateral head profile which is almost straight and shows a small step at the height of the antenna, whereas in D. destitutus the lateral head profile is evenly rounded. In addition, in frontal view, the shape of the lateral head outline is straight in D. melanchaetes and rounded in D. destititus. There are also differences in the shape of the pronotum and in the number of the posterodorsal setae at the eighth abdominal dorsum.  相似文献   
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