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101.
南麂列岛地处亚热带海域,是台湾暖流和江浙沿岸流的交汇处,因而呈现出很好的生物多样性。据调查,南麂列岛附近海域已鉴定的浮游植物甲藻有53种,而到目前为止,对南麂列岛海域甲藻的休眠孢囊种类和分布的调查仍为空白。本文通过对2014年南麂列岛附近海域沉积物中甲藻孢囊的调查研究,在该海域共发现甲藻孢囊10属26种,其中,种类最多的是原多甲藻属(Protoperidinium),有10种;其次是斯氏藻属(Scrippsiella)和亚历山大藻属(Alexandrium),分别有4种,膝沟藻属(Gonyaulax)2种,舌甲藻属(Lingulodinium)、易碎藻属(Fragilidium)、扁甲藻属(Pyrophacus)、翼藻属(Diplopsalis)、裸甲藻属(Gymnodinium)和多沟藻属(Polykrikos)各1种。这些甲藻孢囊中,异养型和自养型甲藻孢囊各13种,自养型甲藻孢囊在数量上所占比例较大(79%)。2014年南麂列岛海域甲藻孢囊丰度较低,每毫升沉积物能检测出2—33个;夏、秋季的孢囊丰富度较高;岙口等相对开放海域的孢囊丰度明显高于岙内各站点。值得注意的是,三种有毒甲藻孢囊,塔玛/相似亚历山大藻(Alexandrium tamarense/affine),具刺膝沟藻(Gonyaulax spinifera)和多边舌甲藻(Lingulodinium polyedra)的孢囊也在样品中检出,并且分别占春季、夏季和秋季孢囊总丰度的37%、23%和27%。本研究为完善南麂列岛甲藻的物种多样性提供了依据。  相似文献   
102.
2010年秋季南海北部浮游植物群落结构研究   总被引:5,自引:0,他引:5  
2010年10月26日-11月24日在南海北部进行了浮游植物群落结构的调查,共鉴定浮游植物4门70属204种(包括未定种12种),浮游植物以硅藻为主,其物种数为146种,其细胞丰度占总浮游植物细胞丰度的93.17%;甲藻次之,其物种数为51种,占总浮游植物细胞丰度的0.63%;金藻门3属4种及蓝藻门2属3种;蓝藻门中以红海束毛藻(Trichodesmium erythraeum)为主。调查区浮游植物的细胞丰度介于0.06×103~107.50×103 cells/L之间,平均值为5.00×103 cells/L。海南岛东北部和粤东近岸表层浮游植物丰度较高。垂直分布上,表层和25 m层的浮游植物细胞丰度较高。浮游植物主要优势种类有菱形海线藻(Thalassionema nitzschioides)、舟形藻(Navicula spp.)、中肋骨条藻(Skeletonema costatum)、旋链角毛藻(Chaetoceros curvisetus)、斯氏几内亚藻(Guinardia stolterforthii)、具槽帕拉藻(Paralia sulcata)等。调查区表层和5 m层Shannon-Wiener多样性指数平均值分别为3.14和2.83,Pielou均匀度指数平均值分别为0.73和0.77;两种指数在表层和5 m层均表现出较高的一致性。环境分析表明除硅酸盐外,浮游植物细胞丰度与其他环境因子均呈极显著性的相关性,主要受到氮元素及磷酸盐的共同限制作用。  相似文献   
103.
In a context of growing fishing pressures and recommendations for an ecosystem approach to fisheries, there is a need to monitor changes in fish communities over time. In this study, we analysed data from scientific trawl surveys carried out on the continental shelf off Guinea between 1985 and 2012. We performed factorial analyses and calculated biodiversity indices to characterise the changes in the structure and composition of fish communities that occurred over the 28-year period in this area, particularly given intensive fishing activities. We show that, over the study period, fish communities on the Guinean shelf were structured primarily according to spatial factors, with temporal changes being less pronounced than expected. However, a temporal analysis of biodiversity indices and species dominance showed that the intensification of fishing had significant effects on the general ecological features of the fish assemblages under study. There was a decrease in fish density and in mean trophic level. In addition, there were changes in species dominance, whereby large, slow-growing species with high commercial value were gradually replaced by smaller, fast-growing species of lesser commercial interest. These results from field observations are in line with some conclusions from previous modelling studies in the same geographical area, and provide further support for the hypothesis of a progressive ‘ecosystem effect of fishing’ occurring in Guinean waters.  相似文献   
104.
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106.
胶州湾及其邻近水域渔业生物多样性的调查研究   总被引:12,自引:7,他引:12  
根据2003年10月-2004年5月逐月采集胶州湾及其邻近水域作业的定置网和底拖网具渔获物的分析与测定,记述了该海区出现的106种渔业生物,并进行了定置网和底拖网的渔获物组成的比较,分析了种类组成特点及生物多样性的季节变化情况。结果表明,本调查区域渔获物以小型低值鱼类、经济无脊椎动物和经济幼鱼为主,渔获个体偏小。据此提出了保护近海生物多样性与合理利用近海渔业资源的一些建议。本次调查还首次记录了我国黄海沿岸罕见的蛇鳗科鱼类一长吻沙蛇鳗Ophisurusmacrorhynchus,为青岛近海的渔业生物多样性的研究增添了新的资料。  相似文献   
107.
景观监测指标体系构建研究   总被引:1,自引:0,他引:1  
为了进一步研究国家尺度的常态化景观格局变化监测,该文围绕景观监测的内涵、景观建模、指标的逻辑架构和监测尺度等方面探讨构建景观监测系统中应重点关注的问题,并提出一种景观监测指标体系:以地理国情普查成果为主要数据源,基于科学性、易于理解性、数据可获性、应用性的原则甄选了26个指标,涵盖有关景观格局的组成要素和其空间配置的8个监测主题,采用PSR逻辑框架,通过分析各指标及其相互作用关系从生态压力、状况以及响应三个方面对景观格局进行评估、预测。研究结果可为相关领域提供参考。  相似文献   
108.
Agricultural chemicals are a notoriously intractable source of environmental pollution. Offering enhanced agricultural productivity, they simultaneously risk degrading the ecological basis upon which agriculture depends. This paper considers chemicalisation as a cause of the erosion of aquatic biodiversity and ecosystem resilience, focusing on the Hawkesbury-Nepean River and the small-scale horticulturalists who supply the city's fresh vegetable markets, working under the pressure of urbanisation, retail monopolies, indifferent land-use planning, and often without access to information about pesticide use in the languages they understand. Arguing that standard practices of ‘risk management’ are unable to adequately control chemical contamination, the paper presents findings from interviews with actors within the ‘assemblage’ of institutions with responsibility for agriculture, water quality, and environmental protection, in order to assess the effectiveness of pesticide governance in the Greater Sydney Basin. It appears that pesticide pollution is far from being tamed: it is rarely measured nor monitored, neither is it a priority of any particular agency. Arguing that public health, the long-term viability of local farming and the ecological well-being of the Hawkesbury-Nepean River are mutually consistent goals, we conclude that these vital elements of the common-weal are currently subject to a system of ‘organised irresponsibility’. The paper concludes by proposing several ways forward.  相似文献   
109.
This paper identifies and defines ecosystem goods and services provided by marine biodiversity. Case studies have been used to provide an insight into the practical issues associated with the assessment of marine ecosystem goods and services at specific locations. The aim of this research was to validate the definitions of goods and services, and to identify knowledge gaps and likely difficulties of quantifying the goods and services. A validated theoretical framework for the assessment of goods and services is detailed, and examples of the goods and services at a variety of case study areas are documented. These results will enable future assessments of marine ecosystem goods and services. It is concluded that the utilisation of this goods and services approach has the capacity to play a fundamental role in the Ecosystem Approach, by enabling the pressures and demands of society, the economy and the environment to be integrated into environmental management.  相似文献   
110.
Abstract: This article examines recent changes to conservation in New Zealand. The argument is influenced by practical experience over the past 15 years, first as conservation planner employed by the Department of Conservation, then as an environmentalist involved in community conservation projects. The development of public‐private partnerships in conservation action over the past 15 years is reviewed. These changes point to the configuration of new landscapes, although the diverse and uncoordinated nature of many contemporary initiatives suggest that future biological communities will comprise a diversity of hybrid mixes from predominantly native to fully non‐native species.  相似文献   
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