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391.
Bruland GL Osborne TZ Reddy KR Grunwald S Newman S DeBusk WF 《Environmental monitoring and assessment》2007,129(1-3):379-395
We assessed recent changes in the distribution of soil total phosphorus (TP) in Water Conservation Area 3 (WCA-3) of the Everglades.
Soil cores were collected in 1992 and 2003 at 176 sites. To reflect hydrologic boundaries within the system, WCA-3 was divided
into three zones (3AN, 3AS, and 3B). Total P was mapped on both a mass (TPm) and a volumetric basis (TPv) to determine if
spatial distributions varied depending on the choice of units. Interpolated maps for both years showed that the highest levels
of TPm were located in 3AN and in boundary areas of all zones that received surface water inputs of P from canals. Increases
in TPm were greatest in central 3AN in an area adjacent to the Miami Canal that received inputs from a water control structure.
Interpolated maps for TPv illustrated that a hotspot present in 1992 had disappeared by 2003. The highest levels of TPv in
2003 were located in northwestern 3AN, a region of WCA-3 that has been chronically overdrained and burned in 1999. From 1992
to 2003, increases in TPm were observed for 53% of the area of WCA-3, while only 16% of WCA-3 exhibited increases in TPv.
In 1992, approximately 21% of WCA-3 had TPm concentrations in the 0–10 cm layer >500 mg kg−1, indicating P enrichment beyond historic levels. Eleven years later, 30% of the area of WCA-3 had TPm >500 mg kg−1. This indicated that during this period, the area of WCA-3 with enriched TPm concentrations increased about one % year−1. 相似文献
392.
Johnson KB Haines TA Kahl JS Norton SA Amirbahman A Sheehan KD 《Environmental monitoring and assessment》2007,126(1-3):55-67
Throughfall and bulk precipitation samples were collected for two watersheds at Acadia National Park, Maine, from 3 May to
16 November 2000, to determine which landscape factors affected mercury (Hg) deposition. One of these watersheds, Cadillac
Brook, burned in 1947, providing a natural experimental design to study the effects of forest type on deposition to forested
watersheds. Sites that face southwest received the highest Hg deposition, which may be due to the interception of cross-continental
movement of contaminated air masses. Sites covered with softwood vegetation also received higher Hg deposition than other
vegetation types because of the higher scavenging efficiency of the canopy structure. Methyl mercury (MeHg) deposition was
not affected by these factors. Hg deposition, as bulk precipitation and throughfall was lower in Cadillac Brook watershed
(burned) than in Hadlock Brook watershed (unburned) because of vegetation type and watershed aspect. Hg and MeHg inputs were
weighted by season and vegetation type because these two factors had the most influence on deposition. Hg volatilization was
not determined. The total Hg deposition via throughfall and bulk precipitation was 9.4 μg/m2/year in Cadillac Brook watershed and 10.2 μg/m2/year in Hadlock Brook watershed. The total MeHg deposition via throughfall and bulk precipitation was 0.05 μg/m2/year in Cadillac Brook watershed and 0.10 μg/m2/year in Hadlock Brook watershed. 相似文献
393.
污水湿地处理工程水力停留时间的测定 总被引:5,自引:0,他引:5
利用UAP对一个湿地处理工程的实际水力停留时间进行了测定,进而对相关问题进行了探讨。 相似文献
394.
滇池湖滨带生态湿地建设中的土地利用问题探析 总被引:6,自引:0,他引:6
随着城市建设不断地向湖滨区扩展,滇池原有的湖滨带被大量用于建设各类建筑物,原有的湖滨带几乎失之殆尽,为保护及修复滇池湖滨完整的生态系统,实施湖滨生态湿地建设工程显得尤为重要,而征地工作难度很大,甚至成为制约湖滨生态带建设工程顺利实施的关键因素之一。本文指出征地工作难度大的主要原因是缺乏征地拆迁补偿标准、拆迁安置费用较高,引起的社会问题复杂等,并提出应采取编制规划控制土地的无序开发、调整农业产业结构、建立新型的征地补偿制度以及妥善安置失地农民等对策措施及建议。 相似文献
395.
Restoration of a Canadian Prairie Wetland with Agricultural and Municipal Wastewater 总被引:1,自引:0,他引:1
3 /day (800,000 US gallons) of municipal wastewater and beef processing wastewater. A large nongovernmental organization hastened
restoration with a development process that outlined restoration goals and management objectives to satisfy a dual mandate
of wastewater treatment and wildlife habitat creation. In 1995, after five years of wastewater additions, the basins had been
refilled and the surrounding uplands had been acquired and restored. The Frank Lake Conservation Area currently provides high-quality
habitat for a variety of wildlife in a region where many of the native plants and animals species have been lost due to habitat
loss and fragmentation. The success of upland and water management strategies is reflected in the increase of target species'
abundance and richness: 50 shorebird species, 44 waterfowl species, 15 raptor species, and 28 other new bird species have
returned to the marsh since restoration. As well, significant N and P reduction occurs as waters flow through the first basin
of the marsh. The management strategies of this project that satisfied a dual mandate serve as a model to guide managers of
other large-scale wetland restoration projects. 相似文献
396.
扎龙河滨湿地对地表径流氮磷污染物的净化作用 总被引:4,自引:1,他引:3
通过对扎龙河滨湿地内龙安桥及水库桥河段水体空间采样分析,研究了2个典型河滨湿地对地表径流中TN、TP及PO43-的净化作用规律.应用空间净化方程分析表明,2个河段河滨湿地在春、夏、秋3季对水体TP及PO43-有持续净化能力,TP净化系数范围为0.00186~0.01175mg·(L·km)-1 ,PO42-净化系数范围为2.5E 4~0.00704mg·(L·km)-1.而河滨湿地对TN的净化作用仅出现在春、夏2季,且夏季净化作用最明显,净化系数达0.07354~0.16036mg·(L·km)-1;在秋季则出现TN沿径流向下累积输出的特征,输出能力最高达0.48175mg·(L·km)-1.2河段的径流量及氮磷污染物输入浓度特征分析表明了河滨湿地对水体TN、TP及PO42-的净化作用受到这2种因素的综合影响而表现出季节性规律特征. 相似文献
397.
J. Shaun Dustin A. Woodruff Miller 《Journal of the American Water Resources Association》2001,37(4):887-898
ABSTRACT: Increased visitation at Grand Teton National Park (GTNP) has raised concerns about impacts on surface water in the park. The purposes of this study are to perform a benchmark trophic state survey for comparison to future evaluations and to identify possible areas of concern. Four watershed regions based on geographic and geologic features were delineated for study. Six Alpine lakes, six Moraine lakes, three Valley lakes, and two Colter Bay lakes are evaluated. Lakes were sampled for total phosphorus (TP), chlorophyll‐a, and transparency. The water quality, as defined by trophic state, in the park is generally good. Oligotrophic to mesotrophic conditions were found in the Alpine and Moraine lakes and mesotrophic to eutrophic conditions were found in the Colter Bay and Valley lakes. High inflow TP concentrations in the park's northeast side may be due to the presence of natural geologic phosphate from the Phosphoria Formation. 相似文献
398.
Mei Shi Xiao Wang Mengying Shao Lun Lu Habib Ullah Hao Zheng Fengmin Li 《Frontiers of Environmental Science & Engineering》2023,17(1):5
399.
上海化学工业区地下水环境质量评价 总被引:3,自引:1,他引:2
以上海化学工业区地下水水质监测资料为基础,结合实际情况选取22项评价因子,依据地下水质量标准,采用综合评价法对该地区的地下水环境质量进行评价分析.评价结果表明,化工区地下水环境质量状况较差,监测项目中无机物超标情况严重,某些金属离子和酸根离子含量较高; 而有机物指标含量均低于方法检出限.此外,该地区地下水水化学特征呈明显的水平分带性,由南至北宏量元素逐渐降低,酚类含量逐渐增高,而重金属含量则基本保持不变,水化学类型由咸水类型向淡水类型转变. 相似文献
400.
人为活动干扰对纳帕海湿地环境影响的研究 总被引:21,自引:2,他引:19
纳帕海是金沙江流域云南西北高原低纬度高海拔的季节性沼泽湿地,有着若尔盖高原湿地和我国北方湿地所不具备的特点,为我国湿地的独特类型。由于其发育于生态脆弱的横断山石灰岩地区,地处长江上游,承接和调节着高原山区的冰雪融水、地表径流和河流水量,控制着土壤侵蚀,对长江下游水位和水量均衡有着重要作用,但长期以来不合理开发利用,使该区生态环境退化问题十分严重。探讨了人为活动干扰对纳帕海湿地环境的影响,结果表明:排水垦殖造田、过牧超载等人类活动的强烈干预对纳帕海湿地发生发展产生显著影响, 40年间湖面积减少了9/10,高原特有水生植物消失或减少,草场资源与牲畜放牧关系严重失调,超载率132.5%,土壤养分衰减下降,湿地严重退化。 相似文献