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51.
52.
The most important meteorological parameter affecting the human energy balance during sunny weather conditions is the mean radiant temperature Tmrt. It considers the uniform temperature of a surrounding surface giving off blackbody radiation, which results in the same energy gain of a human body given the prevailing radiation fluxes. This energy gain usually varies considerably in open space conditions. In this paper, the model ‘RayMan’, used for the calculation of short- and long-wave radiation fluxes on the human body, is presented. The model, which takes complex urban structures into account, is suitable for several applications in urban areas such as urban planning and street design. The final output of the model is, however, the calculated Tmrt, which is required in the human energy balance model, and thus also for the assessment of the urban bioclimate, with the use of thermal indices such as predicted mean vote (PMV), physiologically equivalent temperature (PET) and standard effective temperature (SET*). The model has been developed based on the German VDI-Guidelines 3789, Part II (environmental meteorology, interactions between atmosphere and surfaces; calculation of short- and long-wave radiation) and VDI-3787 (environmental meteorology, methods for the human-biometeorological evaluation of climate and air quality for urban and regional planning. Part I: climate). The validation of the results of the RayMan model agrees with similar results obtained from experimental studies.  相似文献   
53.
基于资源与环境保护的煤炭开发功能区划   总被引:4,自引:0,他引:4  
耿海清 《生态学杂志》2007,26(5):732-736
以往的煤炭开发规划,均未充分考虑发展循环经济和加强生态保护等因素,不利于统筹安排区域层次上的环境保护工作.本文在综合分析区域生态状况、区位条件和经济发展水平等因素的基础上,以资源和环境保护为出发点,将全国的煤炭资源富集区划分为重点开发区、适度开发区和限制开发区3种功能区.结合自然地理条件和生态特征,进一步划分为黄土高原丘陵沟壑区、平原矿粮复合区、云贵山地丘陵区、西北荒漠草原区和蒙东森林草原、草甸草原区等5种典型类型区,针对不同的分区,分别提出了相应的环境保护对策.  相似文献   
54.
Reconnaissance and latent learning in ants   总被引:6,自引:0,他引:6  
We show that ants can reconnoitre their surroundings and in effect plan for the future. Temnothorax albipennis colonies use a sophisticated strategy to select a new nest when the need arises. Initially, we presented colonies with a new nest of lower quality than their current one that they could explore for one week without a need to emigrate. We then introduced a second identical low quality new nest and destroyed their old nest so that they had to emigrate. Colonies showed a highly significant preference for the (low quality) novel new nest over the identical but familiar one. In otherwise identical experiments, colonies showed no such discrimination when the choice was between a familiar and an unfamiliar high-quality nest. When, however, either all possible pheromone marks were removed, or landmarks were re-orientated, just before the emigration, the ants chose between identical low-quality new nests at random. These results demonstrate for the first time that ants are capable of assessing and retaining information about the quality of potential new nest sites, probably by using both pheromones and landmark cues, even though this information may only be of strategic value to the colony in the future. They seem capable, therefore, of latent learning and, more explicitly, learning what not to do.  相似文献   
55.
This paper establishes a framework within which a rapid and pragmatic assessment of river ecosystems can be undertaken at a broad, subcontinental scale, highlighting some implications for achieving conservation of river biodiversity in water‐limited countries. The status of river ecosystems associated with main rivers in South Africa was assessed based on the extent to which each ecosystem had been altered from its natural condition. This requires consistent data on river integrity for the entire country, which was only available for main rivers; tributaries were thus excluded from the analyses. The state of main river ecosystems in South Africa is dire: 84% of the ecosystems are threatened, with a disturbing 54% critically endangered, 18% endangered, and 12% vulnerable. Protection levels were measured as the proportion of conservation target achieved within protected areas, where the conservation target was set as 20% of the total length of each river ecosystem. Sixteen of the 112 main river ecosystems are moderately to well represented within protected areas; the majority of the ecosystems have very low levels of representation, or are not represented at all within protected areas. Only 50% of rivers within protected areas are intact, but this is a higher proportion compared to rivers outside (28%), providing some of the first quantitative data on the positive role protected areas can play in conserving river ecosystems. This is also the first assessment of river ecosystems in South Africa to apply a similar approach to parallel assessments of terrestrial, marine, and estuarine ecosystems, and it revealed that main river ecosystems are in a critical state, far worse than terrestrial ecosystems. Ecosystem status is likely to differ with the inclusion of tributaries, since options may well exist for conserving critically endangered ecosystems in intact tributaries, which are generally less regulated than main rivers. This study highlights the importance of healthy tributaries for achieving river conservation targets, and the need for managing main rivers as conduits across the landscape to support ecological processes that depend on connectivity. We also highlight the need for a paradigm shift in the way protected areas are designated, as well as the need for integrated river basin management plans to include explicit conservation visions, targets, and strategies to ensure the conservation of freshwater ecosystems and the services they provide.  相似文献   
56.
Ecological baselines are disappearing and it is uncertain how marine reserves, here called fisheries closures, simulate pristine communities. We tested the influence of fisheries closure age, size and compliance on recovery of community biomass and life-history metrics towards a baseline. We used census data from 324 coral reefs, including 41 protected areas ranging between 1 and 45 years of age and 0.28 and 1430 km2, and 36 sites in a remote baseline, the Chagos Archipelago. Fish community-level life histories changed towards larger and later maturing fauna with increasing closure age, size and compliance. In high compliance closures, community biomass levelled at approximately 20 years and 10 km2 but was still only at approximately 30% of the baseline and community growth rates were projected to slowly decline for more than 100 years. In low compliance and young closures, biomass levelled at half the value and time as high compliance closures and life-history metrics were not predicted to reach the baseline. Biomass does not adequately reflect the long-time scales for full recovery of life-history characteristics, with implications for coral reef management.  相似文献   
57.
ABSTRACT

This article aims to examine the implications of improving urban resilience that emerge from Chinese practices for reducing urban disaster risk. First, the concept of urban resilience is discussed, the goal of which is to shape a “culture of resilience” to the largest extent possible in order to reduce urban risk. Urban resilience encompasses broad and diverse areas, and thus can be improved in many ways. This article primarily discusses the planning process. Second, the main focus of the discussion on planning process to improve urban resilience is that of the urban risk management planning of Shenzhen, China. This was the first local urban government project in China to have comprehensively and broadly assessed and reduced urban risk, and it is covered along with the Chinese legislation system and current urban resilience programs in China. The findings show that both the Chinese central government and local governments are paying more and more attention to urban resilience through various legislation and programs, even if they are not using the same terminology as other countries.  相似文献   
58.
We studied the non-marine reptile and amphibian species of the volcanic Comoro archipelago in the Western Indian Ocean, a poorly known island herpetofauna comprising numerous microendemic species of potentially high extinction risk and widespread, non-endemic and often invasive taxa. According to our data, the Comoro islands are inhabited by two amphibian species and at least 28 species of reptiles although ongoing genetic studies and unconfirmed historical records suggest an even higher species diversity. 14 of the 28 currently recognized species of terrestrial reptiles (50%) and the two amphibians are endemic to a single island or to the Comoro archipelago. The majority of species are most abundant at low elevation. However, a few endemic species, like the gekkonid lizards Paroedura sanctijohannis and Phelsuma nigristriata, are more common in or even confined to higher altitudes. We created habitat maps from remotely sensed data in combination with detailed species distribution maps produced using comprehensive data from field surveys between 2000 and 2010, literature, and historical locality records based on specimens in zoological collections. Using these data, we assessed the conservation status of the endemic terrestrial reptiles and amphibians according to the IUCN Red List criteria. Our results show that although little area of natural forest remains on the Comoros, many species are abundant in degraded forest or plantations. Competition and predation by invasive species appears to be the most important threat factor for the endemic herpetofauna, together with habitat degradation and destruction, which further favours invasive species. We propose the status Endangered for three species, Vulnerable for one species, Near Threatened for six species, Least Concern for four and Data Deficient for two species. The endemic subspecies Oplurus cuvieri comorensis is proposed for the status Critically Endangered. Based on the results of this study, seven areas of importance for reptile and amphibian conservation on the Comoros are identified. This study shows how remote sensing data can contribute to increasing accuracy and objectiveness of conservation assessments.  相似文献   
59.
The loss of urban green space as a result of urbanization threatens the overall biodiversity of urban areas, and prompts us to consider the importance of existing urban nature more carefully. Because urban ecological systems are in intense interaction with human-social systems, it is fruitful to create an interdisciplinary research and planning framework to ensure the maintenance of biodiversity in urban areas. For this purpose, we adapted a suitable theoretical and conceptual scheme for the setting of Finnish urban development, which provides an example of a situation where a lot of nature has so far remained inside and around urban area. The adapted scheme focuses on the land use change as a result of urban land use planning and development, and may provide a way to address the important variables and feedback mechanisms between information flowing from ecological systems and drivers from the social system. Furthermore, we outlined a more specific framework around the Finnish urban detailed planning process in order to study the interactions between these systems further. After addressing ecology-oriented questions of quantity, quality and needs of urban nature, and human-oriented drivers, such as flow and incorporation of information, knowledge, values and institutions, we identified several challenges in integrating the components of ecological and social systems. Creating common conceptual ground for different actors and disciplines, improving communication in the process, matching contradictory values and perceptions, and improving stakeholder participation would be in the best interest of nature and people of urban areas.  相似文献   
60.
The widespread conversion of natural habitats to agricultural land has created a need to integrate intensively managed landscapes into conservation management priorities. However, there are no clearly defined methods for assessing the conservation value of managed landscapes at the local scale. We used remotely sensed landscape heterogeneity as a rapid practical tool for the assessment of local biodiversity value within a predominantly agricultural landscape in Canterbury, New Zealand. Bird diversity was highly significantly correlated with landscape heterogeneity, distance from rivers and the Christchurch central business district, altitude and average annual household income, indicating that remotely sensed landscape heterogeneity is a good predictor of local biodiversity patterns. We discuss the advantages and limitations of using geographic information systems to determine local areas of high conservation value.  相似文献   
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