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51.
Christopher R. DeRolph Stacy A. C. Nelson Thomas J. Kwak Ernie F. Hain 《Ecology and evolution》2015,5(1):152-163
Headwater species and peripheral populations that occupy habitat at the edge of a species range may hold an increased conservation value to managers due to their potential to maximize intraspecies diversity and species' adaptive capabilities in the context of rapid environmental change. The southern Appalachian Mountains are the southern extent of the geographic range of native Salvelinus fontinalis and naturalized Oncorhynchus mykiss and Salmo trutta in eastern North America. We predicted distributions of these peripheral, headwater wild trout populations at a fine scale to serve as a planning and management tool for resource managers to maximize resistance and resilience of these populations in the face of anthropogenic stressors. We developed correlative logistic regression models to predict occurrence of brook trout, rainbow trout, and brown trout for every interconfluence stream reach in the study area. A stream network was generated to capture a more consistent representation of headwater streams. Each of the final models had four significant metrics in common: stream order, fragmentation, precipitation, and land cover. Strahler stream order was found to be the most influential variable in two of the three final models and the second most influential variable in the other model. Greater than 70% presence accuracy was achieved for all three models. The underrepresentation of headwater streams in commonly used hydrography datasets is an important consideration that warrants close examination when forecasting headwater species distributions and range estimates. Additionally, it appears that a relative watershed position metric (e.g., stream order) is an important surrogate variable (even when elevation is included) for biotic interactions across the landscape in areas where headwater species distributions are influenced by topographical gradients. 相似文献
52.
Recent environmental trends, including (1) an expansion of existing command and control directives, (2) the introduction of market‐based policy instruments, and (3) the adoption of extended producer responsibility, have created a need for new tools to help managerial decision‐making. To address this need, we develop a nonlinear mathematical programming model from a profit‐maximizing firm's perspective, which can be tailored as a decision‐support tool for firms facing environmental goals and constraints. We typify our approach using the specific context of diesel engine manufacturing and remanufacturing. Our model constructs are based on detailed interviews with top managers from two leading competitors in the medium and heavy‐duty diesel engine industry. The approach allows the incorporation of traditional operations‐planning considerations—in particular, capacity, production, and inventory—together with environmental considerations that range from product design through production to product end of life. A current hurdle to implementing such a model is the availability of input data. We therefore highlight the need not only to involve all departments within businesses but also for industrial ecologists and business managers to work together to implement meaningful decision models that are based on accurate and timely data and can have positive economic and environmental impact. 相似文献
53.
目的:比较一次法龈下刮治和根面平整术(FM-SRP)和常规的四分法龈下刮治和根面平整术(Q-SRP)治疗2型糖尿病伴慢性牙周炎的临床疗效,并观察慢性牙周炎治疗对2型糖尿病患者血糖控制的影响。方法:将48例2型糖尿病伴慢性牙周炎患者随机分为2组:FM-SRP组在l天内完成全口所有象限的刮治和根面平整,Q-SRP组每周进行1个象限的刮治,连续4周完成全口治疗。于治疗前、治疗3个月和6个月时,检测菌斑指数(PLI)、牙周探诊深度(PD)、临床附着水平(CAL)、探诊出血(BOP)及空腹血糖(FPG)与糖化血红蛋白(HbAlc)的变化。结果:有3例患者被剔除。与治疗前相比,2种治疗方式在3个月和6个月时的PLI、PD、CAL和BOP均有显著改善(P<0.05),FPG和HbAlc无显著性改变(P>0.05)。但各项指标的变化在2组间均无显著性差异(P>0.05)。结论:本组资料,FM-SRP和Q-SRP两种方法治疗2型糖尿病伴慢性牙周炎均可达到相同的临床效果,但对2型糖尿病患者血糖控制无明显影响。 相似文献
54.
55.
Modelling radiation fluxes in simple and complex environments—application of the RayMan model 总被引:3,自引:0,他引:3
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
56.
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
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
57.
Reconnaissance and latent learning in ants 总被引:6,自引:0,他引:6
Franks NR Hooper JW Dornhaus A Aukett PJ Hayward AL Berghoff SM 《Proceedings. Biological sciences / The Royal Society》2007,274(1617):1505-1509
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
58.
Jeanne L. Nel Dirk J. Roux Gillian Maree Cornelius J. Kleynhans Juanita Moolman Belinda Reyers Mathieu Rouget Richard M. Cowling 《Diversity & distributions》2007,13(3):341-352
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
59.
生态系统服务与人类福祉的和谐关系是区域规划的基石。现有的区域规划较少同时考虑生态系统服务的供需和流域居民的福祉差异。以城市化流域——官厅水库流域为例,应用改进后的CASA模型、IPCC清单法、SolVES模型和问卷调查量化食物供给、碳固持和文化服务以及人类福祉,再结合服务的供需关系及人类福祉水平开展聚类分区,并针对各区情况提出规划建议。结果显示,官厅水库流域内食物供给和文化服务供大于求,而碳固持服务供不应求。流域福祉位于中等水平,分值为3.44(满分5分)。其中,居民的基本物质需求分值最高(3.64),收入分值(3.00)明显低于流域整体水平。除此之外,居民认为供水、医疗条件和收入这些福祉要素仍有待改善。流域可分为城市发展区、城郊休闲区、生态涵养区和文化建设区。在各区需采用因地制宜的方式,通过增大植被覆盖面、开展文旅产业和推动冰雪项目等形式,提高居民生活质量和维持区域可持续性。 相似文献
60.
以保护和提高生态系统服务功能为原则,优化生态空间格局对于保障区域生态系统稳定性具有重要作用。以南方丘陵地区为研究对象,基于土地利用数据,评估了南方丘陵地区20年间生态系统服务功能的时空变化,据此提出区域国土空间规划建议。结果表明:(1)1995-2000年间森林生态系统面积与生态系统服务功能急剧下降,在2000年之后两者均逐渐恢复。(2)南方丘陵地区生态系统服务主要受自然因素与社会经济因素的影响,空间分布呈自东南至西北逐渐降低的趋势。(3)空间叠加分析南方丘陵地区生态敏感性,划定4个生态功能区,明确重点保护区范围,严格规范对服务供给区、适度开发区及城镇建设区的干扰程度,在现有国土空间规划方案的基础上进行合理优化。研究成果探讨了生态系统服务格局在国土空间规划过程中的重要作用,可为进一步评估优化南方丘陵地区的生态空间格局提供科学参考。 相似文献