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21.
A milestone in the field of European water protection policy is the European Union’s Water Framework Directive (WFD), which came into force in December 2000 and which integrates the management of European waters in many ways. In this study, we start by focusing on management issues connected to the implementation of the WFD and pose a question: “what type of models would be the most suitable for use in the context of the WFD?” With this question in mind, we aim to establish a set of operational and functional selection criteria for (computer) models whose application is intended to support decision-making related to a particular water management issue. These so-called “benchmark criteria” should help water managers and other model users in choosing appropriate models, e.g., for the WFD implementation purposes. We first describe models and their use in general and then propose an approach for setting the benchmark criteria for models, basing it on the concept of uncertainty management, while keeping firmly in mind the important role of citizens and citizen organizations in water management. The suggested benchmark criteria are in the form of 14 questions through which each model can be evaluated. Finally, the process for testing and refining the benchmark criteria is highlighted.  相似文献   
22.
1999年,在毛里塔尼亚和塞内加尔的塞内加尔三角洲下部,槐叶苹(Salvinia moesta)的侵入对当地居民的社会经济状况以及湿地生物多样性构成严重的威胁.分别于2000年5月在塞内加尔和毛里塔尼亚及2001年4月在塞内加尔的河面引进槐叶苹象甲(Cyteobagous salviniae),最终实现了对槐叶苹的有效生物控制.2001年10月,象甲起到的作用已非常明显.植物的颜色由绿色变为深褐色或黑色,槐叶苹最终沉入水底.2001年11~12月对槐叶苹象甲扩散的监控证实了生物控制结果的真实性.至2002年4月已有结论,塞内加尔河畔槐叶苹不再成为问题.  相似文献   
23.
Effects of simulated acid rain (a mixture of H(2)SO(4) and HNO(3); pH(3)) on soil microbiology were studied in a field experiment in northern Finland. Irrigated control plots received the same amount of spring water (pH 6) as the acid treated plots. Fungal lengths and total bacterial numbers were studied after the treatments had continued for three growing seasons. The numbers of bacteria in five physiological groups (those utilizing starch, protein, pectin, xylan, or cellulose) were measured by MPN (most probable number) techniques. The lengths of total and FDA active fungal hyphae were not significantly different between the acid treated and the control plots. The counts of total bacteria were not significantly different between treatments, but the MPNs of all five physiological groups of bacteria were approximately 60% lower in the acid treated plots than in the controls.  相似文献   
24.
This study provides a case example of an energy company that prioritized occupational safety and health and accident reduction as long-term, strategic development targets. Furthermore, this study describes the monetary benefits of this strategic decision. Company-specific accident indicators and monetary costs and benefits are evaluated. During the observation period (2010–2016), strategic investments in occupational safety and health cost the company EUR 0.8 million. However, EUR 1.8 million were saved in the same period, resulting in a 2.20 cost–benefit ratio. The trend in cost savings is strongly positive. Annual accident costs were EUR 0.4 million lower in 2016 compared to costs in 2010. This study demonstrates that long-term, strategic commitment to occupational safety and health provides monetary value.  相似文献   
25.
The effects of prolonged simulated acid rain on the biochemistry of Scots pine needles were studied in Finnish Lapland. Pine trees were exposed by spraying the foliage and soil with either clean water or simulated acid rain (SAR; both sulphuric and nitric acids) over the period 1985-1991. The concentrations of carbohydrates (starch, glucose, fructose, sucrose) in one-year-old pine needles were not affected by SAR-treatments. The SAR-treatments did not have significant effects on protein bound amino acids, which was true also for most of the free amino acids. However, the citrulline concentration was over three-fold greater in the foliage of pines exposed to SAR of pH 3 compared to irrigated controls. The concentrations of total phenolics, individual low molecular weight phenolics and soluble proanthocyanidins were not affected by the treatments, but insoluble proanthocyanidins had increased in acid-treated trees. Some of the studied biochemical compounds showed significant differences between two sub-areas (similar treatments) only 120 m apart.  相似文献   
26.
本文运用了以遥感为基础的土地利用和森林分类,研究了大流域氮输出-存留空间模型N_EXRET.根据经验研究,估算了用以描述农业、林业和泥炭产量(收获)所起作用的输出系数.通过一小块集水试验区内详细记录的数据,求得林业活动典型系数.讨论了将该模型应用于奥鲁(Oulujoki)河流域(22840km2)的模拟效果.将氮通量预估模型与该流域不同地点测得的氮能量值进行了比较.根据资源配比,农业占总输出的17%,变动范围为8%(最高的亚流域)约38%(最低的近海亚流域).林业约占16%,不同亚流域间变化较小(11%~24%).在各亚流域中,所得到的氮输出总额中有7%~37%存留下来.根据质量平衡和敏感度分析,估计湖泊存留为5~10kg/hm2·a,泥炭地为0~1kg/hm2·a.从三条邻近的河流流域中取得的试验数据证实了模型结论.但是,对那些土地利用和沉积格局与北部流域明显不同的流域,还需进一步研究.  相似文献   
27.
28.
We surveyed the regional distribution of conifer defoliation in Finland with an extensive monitoring network during 1995–2006 (EU Forest Focus Level I). The average defoliation in the whole Finland was 10.3% in pine and 19.9% in spruce. The sharp changes were often related to abiotic and biotic factors. The mean age of the stand explained more than one half of the between-plot variance in defoliation. In a variance component analysis, the main effect of years was negligible, while most of the random variation was due to plot main effect and plot × year interaction. About one fifth of the defoliation could be attributed to abiotic or biotic damage, and there were strong local correlations, e.g., between the changes in defoliation and degree of pine sawfly (Diprionidae) damage. There were clear temporal and spatial patterns in the incidence of the most important causes [Scots pine: Scleroderris canker (Gremmeniella abietina), pine shoot beetles (Tomicus sp.), and pine sawflies (Diprion pini, Neodiprion sertifer); Norway spruce: rust fungi (primarily Chrysomyxa ledi)]. Our results suggest that extensive monitoring networks can reveal useful information about the widespread outbreaks of pest organisms (insects and fungi) already in their increase phases, giving some time for management decisions. In a changing climate, large-scale, regular monitoring of tree health, including abiotic and biotic causes, is more important than ever before.  相似文献   
29.
Ambio - The Circumpolar Biodiversity Monitoring Programme (CBMP) provides an opportunity to improve our knowledge of Arctic arthropod diversity, but initial baseline studies are required to...  相似文献   
30.
The terrestrial chapter of the Circumpolar Biodiversity Monitoring Programme (CBMP) has the potential to bring international multi-taxon, long-term monitoring together, but detailed fundamental species information for Arctic arthropods lags far behind that for vertebrates and plants. In this paper, we demonstrate this major challenge to the CBMP by focussing on spiders (Order: Araneae) as an example group. We collate available circumpolar data on the distribution of spiders and highlight the current monitoring opportunities and identify the key knowledge gaps to address before monitoring can become efficient. We found spider data to be more complete than data for other taxa, but still variable in quality and availability between Arctic regions, highlighting the need for greater international co-operation for baseline studies and data sharing. There is also a dearth of long-term datasets for spiders and other arthropod groups from which to assess status and trends of biodiversity. Therefore, baseline studies should be conducted at all monitoring stations and we make recommendations for the development of the CBMP in relation to terrestrial arthropods more generally.  相似文献   
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