全文获取类型
收费全文 | 111篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 3篇 |
环保管理 | 15篇 |
综合类 | 24篇 |
基础理论 | 10篇 |
污染及防治 | 23篇 |
评价与监测 | 40篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有117条查询结果,搜索用时 46 毫秒
61.
Federal regulations require operators of nuclear and coal-fired power-generating stations to estimate the number of fish impinged on intake screens. During winter months, impingement may range into the hundreds of thousands for certain species, making it impossible to count all intake screens completely. We present graphs for determinig the appropriateoptimal subsample that must be obtained to estimate the total number impinged. Since the number of fish impinged tends to change drastically within a short time period, the subsample size is determined based on the most recent data. This allows for the changing nature of the species-age composition of the impinged fish. These graphs can also be used for subsampling fish catches in an aquatic system when the size of the catch is too large to sample completely. 相似文献
62.
本文介绍了日本产业废弃物的采样方法并详细介绍了溶出试验和含量试验试液的制备方法及其适用范围,对测定重金属用试液的前处理方法也做了简要介绍。 相似文献
63.
通过考察气态污染物采样方法的基本原理,对比分析国内外常压采样系统和加压采样系统的设计特征,选择煤气化过程中5种常见气态污染物为分析对象,列举常用的化学分析法和仪器分析法,为加压气化装置采样系统的设计提供参考材料和建议,归纳了一些有助于提高气态污染物检测数据可靠性的措施,希望能为煤气化过程中(特别是加压煤气化过程中)气态污染物采样系统的设计提供思路和借鉴。 相似文献
64.
65.
燃煤锅炉烟气中CPM与水溶性离子监测方法及应用研究 总被引:7,自引:0,他引:7
建立燃煤锅炉烟气可凝聚颗粒物(CPM)与水溶性离子监测采样方法,并应用于北京市典型烟气净化工艺燃煤锅炉排放监测。结果表明,北京市燃煤锅炉烟气中总颗粒物(TPM)基准排放质量浓度最高达82.4 mg/m3,最低14.0 mg/m3,其中CPM占TPM的43.5%~92.2%,水溶性离子对TPM的贡献水平为31.4%~62.2%。烟温对水溶性离子的分布形态有显著影响,进而影响TPM中可过滤颗粒物(FPM)和CPM的分配比例。颗粒物和水溶性离子的排放与烟气含湿量之间无显著相关性,而与燃煤锅炉烟气脱硫除尘净化工艺和脱硫产物的溶解度及其脱除方式密切相关。 相似文献
66.
Opportunistic reporting of species observations to online platforms provide one of the most extensive sources of information about the distribution and status of organisms in the wild. The lack of a clear sampling design, and changes in reporting over time, leads to challenges when analysing these data for temporal change in organisms. To better understand temporal changes in reporting, we use records submitted to an online platform in Sweden (Artportalen), currently containing 80 million records. Focussing on five taxonomic groups, fungi, plants, beetles, butterflies and birds, we decompose change in reporting into long-term and seasonal trends, and effects of weekdays, holidays and weather variables. The large surge in number of records since the launch of the, initially taxa-specific, portals is accompanied by non-trivial long-term and seasonal changes that differ between the taxonomic groups and are likely due to changes in, and differences between, the user communities and observer behaviour. Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01550-w. 相似文献
67.
Junxia Wang Maud Mercury Maurice Millet Michel Montury 《Environmental pollution (Barking, Essex : 1987)》2009,157(2):365-370
To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min−1 for the exposed fiber and 0.166-0.929 mL min−1 for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min-1) was consistent with that in the lab (34.5 mL min-1). SR for dichlorvos in the field (32.4 mL min−1) was consistent with that in the lab (34.5 mL min−1). The trends of temporal concentration and the inhalation exposure were also obtained. 相似文献
68.
Both long duration (>6 h) and high temperature (up to 139 °C) sampling efforts were conducted using ambient air sampling methods to determine if either high volume throughput or higher than ambient air sampling temperatures resulted in loss of target polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs) from a polyurethane foam (PUF) sorbent. Emissions from open burning of simulated military forward operating base waste were sampled using EPA Method TO-9A for 185 min duration using a filter/PUF/PUF in series combination. After a 54 m3 sample was collected, the sampler was removed from the combustion source and the second PUF was replaced with a fresh, clean PUF. An additional 6 h of ambient air sampling (171 m3) was conducted and the second PUF was analyzed to determine if the PCDD/PCDF transferred from the filter and the first PUF. Less than 4.4% of the initial PCDD/PCDF was lost to the second PUF. To assess the potential for blow off of PCDD/PCDF analytes during open air sampling, the mobility of spiked mono- to hepta-PCDD/PCDF standards across a PUF sorbent was evaluated from ambient air temperatures to 145 °C with total volumes between 600 L and 2400 L. Lower molecular weight compounds and higher flow amounts increased release of the spiked standards consistent with vapor pressure values. At 600 L total sampled volume, the release temperature for 1% of the tetra-CDD (the lowest chlorinated homologue with a toxic compound) was 87 °C; increasing the volume fourfold reduced this temperature to 73 °C. 相似文献
69.
R. Grover L. A. Kerr K. Wallace K. Yoshida J. Maybank 《Journal of environmental science and health. Part. B》2013,48(4):331-347
Abstract Residues of 2,4‐D (2,4‐dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966–68 and 1970–75 periods were determined by gas‐liquid Chromatographic techniques. Initially, individual esters of 2,4‐D were characterized by retention times and confirmed further by co‐injection and dual column procedures. Since 1973, however, only total 2,4‐D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4‐D, with butyl esters being found most frequently. The daily 24‐hr mean atmospheric concentrations of 2,4‐D ranged from 0.01 to 1.22 μg/m3, 0.01 to 13.50 μg/m3, and 0.05 to 0.59 μg/m for the iso‐propyl, mixed butyl and iso‐octyl esters, respectively. Even when the samples were analysed for the total 2,4‐D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 μg/m. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 μg/m3 of 2,4‐D. In another 40% of the samples, the levels of 2,4‐D ranged from 0.01 to 0.099 yg/m. Only about 30% of the samples contained 2,4‐D concentrations higher than 0.1 μg/m3, with only 10% or less exceeding 1 μg/m3. None of the samples, obtained with the high volume particu‐late sampler, showed any detectable levels of 2,4‐D, indicating little or no transport of 2,4‐D adsorbed on dust particles or as crystals of amine salts. 相似文献
70.
Starr M Ukonmaanaho L Sibley PK Hazlett PW Gordon AM 《Environmental monitoring and assessment》2007,125(1-3):123-136
Open precipitation and throughfall was collected at a Norway spruce stand in Finland using funnel-type collectors and at a
black spruce stand in Canada using trough-type collectors. The presence or absence of a rim on the funnel, funnel diameter
(9, 14 and 20 cm) and length of sampling period (1, 2 and 4 weeks) on monthly values were evaluated at the Norway spruce stand,
and the number of collectors required for defined levels of accuracy and precision of throughfall loads to be reached and
the influence of the spatial arrangement of collectors on solute concentrations was studied at both stands. The presence of
a rim had no significant effect on open precipitation and throughfall amounts, but did on throughfall DOC, Ca2+, Mg2+, K+, Na+ and Cl− ion loads. Deposition loads increased with decreasing funnel diameter; for open precipitation, this was due to increased
catch efficiency while for throughfall the increase was attributed to canopy interaction and leaching of litter trapped in
the collectors. Calculated monthly H+ loads decreased and those for all other constituents increased with collection period length. Using 15 collectors at the
Norway spruce stand would allow throughfall loads to be determined to within 20% of the true mean weekly value with a confidence
level of 95% for most solute, but not for NH4
+–N, NO3
−–N, Mg2+ and SO4
2−-S. Using 15 trough collectors, the same confidence level at the more heterogeneous black spruce stand would only be achieved
for H+, Cl−, DOC and SO4
2−-S loads. In both stands, using either random or systematic placements of throughfall collectors gave similar results. 相似文献