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41.
红树植物白骨壤小苗对模拟潮汐淹浸时间的生长适应性   总被引:2,自引:0,他引:2  
廖宝文  邱凤英  张留恩  韩静  管伟 《环境科学》2010,31(5):1345-1351
室内模拟12个潮汐淹浸时间处理(2、4、6、8、10、12、14、16、18、20、22、24h·d-1)对红树植物白骨壤Avicennia marina小苗生长的影响,测定不同淹水时间处理下白骨壤小苗的叶绿素含量、根活力、生长量、生物量及净光合速率等10项生长信息指标.210d的试验结果表明,叶绿素含量、根活力、生物量及生长量均随淹水时间的延长先升后降,并在16h·d-1处出现骤变分界点,淹水时间超过16h·d-1后,白骨壤小苗的生物量、生长量均显著低于淹水时间16h·d-1的处理;月均地茎增量、月均叶片增量、单株茎干重、单株根干重及总生物量均在淹水10h·d-1处理下最大.结合主成分分析得出结论,白骨壤小苗在淹水时间16h·d-1的处理下均能正常生长,最适淹水时间为8~12h·d-1,临界淹水时间为16h·d-1.  相似文献   
42.
To understand the scope and scale of the loss of biodiversity, tools are required that can be applied in a standardized manner to all species globally, spanning realms from land to the open ocean. We used data from the International Union for the Conservation of Nature Red List to provide a synthesis of the conservation status and extinction risk of cetaceans. One in 4 cetacean species (26% of 92 species) was threatened with extinction (i.e., critically endangered, endangered, or vulnerable) and 11% were near threatened. Ten percent of cetacean species were data deficient, and we predicted that 2–3 of these species may also be threatened. The proportion of threatened cetaceans has increased: 15% in 1991, 19% in 2008, and 26% in 2021. The assessed conservation status of 20% of species has worsened from 2008 to 2021, and only 3 moved into categories of lesser threat. Cetacean species with small geographic ranges were more likely to be listed as threatened than those with large ranges, and those that occur in freshwater (100% of species) and coastal (60% of species) habitats were under the greatest threat. Analysis of odontocete species distributions revealed a global hotspot of threatened small cetaceans in Southeast Asia, in an area encompassing the Coral Triangle and extending through nearshore waters of the Bay of Bengal, northern Australia, and Papua New Guinea and into the coastal waters of China. Improved management of fisheries to limit overfishing and reduce bycatch is urgently needed to avoid extinctions or further declines, especially in coastal areas of Asia, Africa, and South America.  相似文献   
43.
码头工程项目环境监理实践与探析   总被引:1,自引:0,他引:1  
简述了环境监理在建设项目环境管理中的作用.以无锡港城郊港区胡埭作业区码头工程建设项目为实例,详细介绍了环境监理方案编制的内容,项目监理的重点.指出,环境监理须经过进一步实践和探索,增强针对性,提高环境监理工作水平.  相似文献   
44.
An outdoor experiment was set up to investigate the effects of used lubricating oil(5 L/m~2)on Aegiceras corniculatum Blanco. and Avicennia marina(Forsk)Vierh.,two salt-excreting mangroves.A.marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling.When treated with canopy-oiling,half of A.corniculatum plants survived for the whole treatment time(90 d);but,for A.marina,high mortality (83%)resulted from canopy-oiling within 3 weeks and no plants survived for 80 d.Base-oiling had no lethal effects on A.corniculatum plants even at the termination of this experiment,but 83% of A.marina plants died 80 d after treatment.Forty days after canopy- oiling,93% ofA.corniculatum leaves fell and no live leaves remained on A.marina plants.By the end of the experiment,base-oiling treatment resulted in about 45% ofA.corniculatum leaves falling,while all A.marina leaves and buds were burned to die.Lubricating oil resulted in physiological damage to A.corniculatum leaves,including decreases in chlorophyll and carotenoid contents,nitrate reductase,peroxidase and superoxide dismutase activities,and increases in malonaldehyde contents.For both species,oil pollution significantly reduced leaf,root,and total biomass,but did not significantly affect stem biomass.Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.  相似文献   
45.
氮限制对三种赤潮藻生长以及种间竞争效应的影响   总被引:2,自引:0,他引:2  
为了了解不同类别的赤潮藻类对氮(N)限制的响应,在实验室单独培养以及混合培养条件下,研究了N限制对3种典型赤潮微藻(中肋骨条藻、锥状斯氏藻和海洋卡盾藻)生长的影响.结果显示,N限制对3种赤潮藻类的生长均具有明显影响,其中中肋骨条藻对N限制较为敏感.混合培养体系中,藻细胞生长同时还受到种间竞争的明显抑制;而在3种藻混合培养条件下,种间竞争成为了藻细胞生长的决定性因素,锥状斯氏藻和海洋卡盾藻能对中肋骨条藻的生长能产生协同抑制作用.锥状斯氏藻是一种可形成孢囊的种类,N限制和种间竞争能促进其孢囊的提前形成,并且种间竞争能显著提高孢囊的形成率.  相似文献   
46.
不同氮源对海洋卡盾藻生长和硝酸还原酶活性的影响   总被引:3,自引:0,他引:3  
在实验室条件下,研究了不同氮源对海洋卡顿藻(Chattonella marina)生长和藻细胞硝酸还原酶活性(NRA)的影响.结果表明,海洋卡盾藻可以有效利用无机氮源,如NH4Cl、NaNO3、NaNO2,对有机氮源如尿素、甘氨酸和1,4-丁二胺盐酸盐也有一定的利用能力,但不能有效利用丙氨酸.海洋卡顿藻的生长速率与营养盐的同化速率不一致,存在一定的滞后效应,最大比生长率可达到0.7 d-1.藻细胞硝酸还原酶活性在以NaNO3为氮源时,藻细胞酶活性(NRAmax)最大,为20.6 fmol/(min·cell).  相似文献   
47.
模拟分析白骨壤湿地系统中Ni的分配循环及其净化效果   总被引:3,自引:0,他引:3  
在温室中建立红树林植物白骨壤模拟湿地系统,分别用正常、5倍和10倍浓度的人工配置的城市污水每周定时定量对模拟系统污灌2次,用海水作对照,持续1 a.研究重金属Ni在系统中的分配、循环和被净化的效果以及系统对Ni的承受能力.结果表明:加入系统的Ni主要留存在土壤中,很少迁移到植物体和凋落物中.模拟系统对重金属Ni的净化效果显著,达到92%以上.根据物质平衡模型计算得土壤子系统Ni的环境容量较大,因此整个模拟系统对Ni污染的承受力较大.  相似文献   
48.
Many drivers of mangrove forest loss operate over large scales and are most effectively addressed by policy interventions. However, conflicting or unclear policy objectives exist at multiple tiers of government, resulting in contradictory management decisions. To address this, we considered four approaches that are being used increasingly or could be deployed in Southeast Asia to ensure sustainable livelihoods and biodiversity conservation. First, a stronger incorporation of mangroves into marine protected areas (that currently focus largely on reefs and fisheries) could resolve some policy conflicts and ensure that mangroves do not fall through a policy gap. Second, examples of community and government comanagement exist, but achieving comanagement at scale will be important in reconciling stakeholders and addressing conflicting policy objectives. Third, private‐sector initiatives could protect mangroves through existing and novel mechanisms in degraded areas and areas under future threat. Finally, payments for ecosystem services (PES) hold great promise for mangrove conservation, with carbon PES schemes (known as blue carbon) attracting attention. Although barriers remain to the implementation of PES, the potential to implement them at multiple scales exists. Closing the gap between mangrove conservation policies and action is crucial to the improved protection and management of this imperiled coastal ecosystem and to the livelihoods that depend on them.  相似文献   
49.
Abstract: Spatial and temporal dynamics of ecological processes have long been considered important in marine systems, but seldom have conservation objectives been set for them. Climate change makes the consideration of the dynamics of ecological processes in the design of marine protected areas critical. We analyzed sea‐surface temperature (SST) trends and variability in Great Barrier Reef Marine Park (GBRMP) for 25 years and formulated and tested whether three sets of notional conservation objectives were met to illustrate the potential for planning to address climate change. Given mixed and limited evidence that no‐take areas increase resilience to disturbances such as anomalously high temperatures (i.e., temperatures ≥1 °C above weekly mean temperature), our conservation objectives focused on areas less likely to be affected by such events at extents ranging from the entire Great Barrier Reef to the system of no‐take zones and individual no‐take zones. The objective sets were (1) at least 50% of temperature refugia (i.e., pixels that had high‐temperature anomalies <5% or <7% of the time) within no‐take zones, (2) maximum occurrence of high‐temperature anomalies is <10%,< 20%, or <30% of total no‐take area 90% of the time, and (3) coverage of any single no‐take zone by high‐temperature anomalies occurs <5% or <10% of the time. We used satellite imagery from 1985–2009 to measure SST to determine high‐temperature anomalies. SSTs in the Great Barrier Reef increased significantly in some regions, and some of the conservation objectives were met by the park's current zoning plan. Dialogue between conservation scientists and managers is needed to develop appropriate conservation objectives under climate change and strategies to meet them.  相似文献   
50.
Nylon bags containing yellow leaves of Rhizophora apiculata and Avicennia marina, were immersed for 80 days from August to October, 1996. the decomposing leaves were collected every 10 days and analysed for dry weight loss and six biochemical parameters: tannins, total amino acids, total sugars, total nitrogen, total lipids and fatty acid profile. the leaf weight initially decreased very rapidly by about 50% of the start in two species of mangroves within 10 days. Similar changes were observed with tannins, total amino acids and sugars. However, the concentration of nitrogen increased significantly with decomposition. There was no significant change in total lipid and fatty acid profile. the highest concentration of fatty acid in the decomposing leaves was palmitic acid (16:0). Unsaturated fatty acids such as, 18:1 w7c and 18:1 w9c were found to be present in decomposing leaves of both species.  相似文献   
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