全文获取类型
收费全文 | 1210篇 |
免费 | 56篇 |
国内免费 | 244篇 |
专业分类
安全科学 | 65篇 |
废物处理 | 37篇 |
环保管理 | 288篇 |
综合类 | 568篇 |
基础理论 | 174篇 |
环境理论 | 2篇 |
污染及防治 | 200篇 |
评价与监测 | 44篇 |
社会与环境 | 94篇 |
灾害及防治 | 38篇 |
出版年
2023年 | 9篇 |
2022年 | 38篇 |
2021年 | 37篇 |
2020年 | 40篇 |
2019年 | 33篇 |
2018年 | 34篇 |
2017年 | 61篇 |
2016年 | 68篇 |
2015年 | 48篇 |
2014年 | 60篇 |
2013年 | 140篇 |
2012年 | 66篇 |
2011年 | 53篇 |
2010年 | 52篇 |
2009年 | 66篇 |
2008年 | 66篇 |
2007年 | 97篇 |
2006年 | 82篇 |
2005年 | 64篇 |
2004年 | 44篇 |
2003年 | 65篇 |
2002年 | 51篇 |
2001年 | 39篇 |
2000年 | 36篇 |
1999年 | 25篇 |
1998年 | 27篇 |
1997年 | 13篇 |
1996年 | 16篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1510条查询结果,搜索用时 46 毫秒
171.
钢铁冶炼渣是钢铁企业开展资源利用的重点,冶炼渣的综合利用途径及利用水平与处理加工技术有密切关系,冶炼渣最多,影响大,易见成效,有利于综合利用工作向纵深发展,本文提出了合理利用建议。 相似文献
172.
中国有机食品的生产和认证 总被引:9,自引:0,他引:9
中国的有机食品开发和认证工作起步于上个世纪末。经过近十年的发展,有机食品的开发行为已基本得到了社会各界的认可,更多的基地、企业、高校、科研单位以及政府部门都参与到这一新兴产业中,有机食品产业蓄势待发。目前,如何正确分析和处理有机食品开发过程中的一些问题以引导和促进该项事业的健康发展,已显得尤为重要。本文在总结近年来工作的基础上,提出了中国有机食品开发工作中存在的一些不足之处,希望能够起到抛砖引玉的作用,使更多的人参与到有机食品认证管理的讨论之中。 相似文献
173.
174.
Concentrations of heavy metals (Pb, Zn, Cd, Cu) were determined in soils and vegetables (chrysanthemum, spinach and four cultivars of Chinese cabbage from the area adjacent to a Pb/Zn mine in Shaoxing, Zhejiang province, China, and compared with the Chinese National Standards for Soil Environmental Quality. The accumulation of heavy metals in cabbage cv. Siyuegreen was investigated at different distances from the center of the mine. The vegetable plantation soils were polluted with Pb, Cd, Cu and Zn, especially by Pb and Cd. The levels of Pb and Cd were 20 and 30 times higher than the permitted standards, indicating that this Pb/Zn mining area is unsuitable for agricultural use. Chinese cabbage, chrysanthemum and spinach had different enrichment coefficients. The enrichment coefficient of Cd from soil to roots of chrysanthemum was >80% and from roots to leaves of cabbage cv. Shanghaigreen was >120%. These vegetables were polluted by heavy metals and could not be regarded as safe for human consumption. Environmental accumulation of heavy metals in the vegetable plantation soils was proportional to heavy metal accumulation in vegetables and both were inversely proportional to the distance from the lead/zinc mine. 相似文献
175.
从开采方法、土地复垦与综合治理、经济和政策等方面采取措施,可以最大限度地减小采矿对土地资源的破坏,治理好矿区土地资源,保护好耕地,实现粮食产需总量的大体平衡。“保护粮食安全”关键是抓好耕地保护,根据可持续发展原则,综合考虑矿业经济发展与矿区生态环境保护的关系,走矿业“绿色开采”的道路,研究有利于矿区耕地保护的采矿新技术,使资源开发与耕地保护协调发展,同时还应对煤矸石和粉煤灰进行充分利用、防治水体受到污染、采用先进的土地复垦技术对土地资源的浪费和破坏进行治理,把土地复垦中的经济效益、社会效益和生态效益统一起来,为粮食生产奠定基础。 相似文献
176.
Bettinetti R Croce V Galassi S Volta P 《Environmental science and pollution research international》2006,13(1):59-66
- DOI: http://dx.doi.org/10.1065/espr2006.01.010
Background, Aims and Scope Although pp'DDT usage was strongly limited or banned in most parts of the world during the last three or four decades, the
parent compound, its homologues and their metabolites still occur at levels which might pose a risk for many ecosystem components.
A case of DDT pollution of industrial origin was discovered in 1996 in Lake Maggiore, the second largest (212 km2) and deepest
(370 m) lake in Italy, causing concern for wildlife and human health. The extensive monitoring of many biotic and abiotic
compartments which followed from 1998 in order to assess the pollution level and its trend in time, provided a great availability
of data referring to DDT contamination of the different fish species of the lake. In this study, the recent contamination
levels in selected fish species were compared to those measured in 1998 to evaluate the temporal pollution trend of the lake
and its natural recovery, given that no remediation measures were carried out on the contaminated soils and sediments in this
time span. Moreover, a modelling approach to test the equilibrium condition between water and pelagic fish species was used.
Analytical results of pp'DDT and pp'DDE concentrations in lake water were used as input data in the bioenergetic model by
Connolly & Pedersen (1988) to calculate concentrations in two fish species and to compare the predicted and the measured contamination.
Methods Sampling and analytical determination of DDT homologues in lake water: Five water sampling campaigns were carried out from
May 2002 to February 2004 in three sampling sites of Lake Maggiore. Suspended and dissolved pollutants were determined separately.
Quantitative DDT homologue analyses were performed by HRGC coupled with ECD detection by the external standard method. Single
water extracts were put together in correspondence with the stratification zones of the water column inferred on the basis
of the temperature profile to improve analytical sensitivity. Selection of fish data: Concentrations of DDT and DDE in fishes
were selected from recent literature (CIPAIS 2003, 2004). Bioaccumulation model: The bioenergetic model proposed by Connolly
& Pedersen (1988) was used to assess the bioaccumulation of pp'DDT and pp'DDE of Alosa fallax (landlocked shad) and Coregonus
spp. (whitefish), selected among the different species as representative of a secondary consumer level.
Results and Discussion The average concentrations of pp'DDT and pp'DDE in water to be used as input data in the bioenergetic model were obtained
considering all the concentrations measured at the three sampling stations in the epylimnion where the fish species considered
in this study spend most of their life. The resulting values were 0.05 and 0.16 ng/L for pp'DDT and pp'DDE, respectively.
Average measured pp'DDT and pp'DDE concentrations in landlocked shad were 0.81 +/- 0.39 and 1.69 +/- 0.71 mg/kg lipids, respectively,
and were 0.29 +/- 0.12 and 1.06 +/- 0.41 mg/kg lipids for the whitefish. Calculated and measured values turned out to be
in quite good agreement for pp'DDT, while measured pp'DDE concentrations were higher than expected on the basis of the bioenergetic
model in both species. Probably metabolic transformations of pp'DDT accumulated in fish tissues in the past are responsible
for the observed differences between calculated and expected pp'DDE concentrations in fish.
Conclusions Pelagic fishes of Lake Maggiore seem to maintain the DDT accumulated during their life time and the most efficient mechanism
responsible for the fish population recoveries is probably their generation changes; for this reason, equilibrium models cannot
be used until negligible pp'DDT concentrations are reached in fish tissues.
Recommendations and Outlook The limit proposed for pp'DDT in water by the EU Directive 2000/60, which will come in force in 2008, is 0.2 ng/L, four times
higher than the average concentration measured in Lake Maggiore waters. Nevertheless, concentrations measured in Lake Maggiore
fish were very close and sometimes exceeded the Maximum residue limits (MRLs) settled by the Italian legislation for foods
(0.1 mg/kg w.w. for fish containing 5–20% lipid). It seems, therefore, that the 'environmental quality standard' of 0.2 ng/L
cannot guarantee the suitability of fish for human consumption. 相似文献
177.
固体废弃物在新型墙体材料中的资源化利用 总被引:1,自引:0,他引:1
探讨了工业废弃物、农业废弃物和建筑废弃物在新型墙体材料中的各种资源化利用。将各种固体废弃物变废为宝,综合利用,能够减少对环境的污染,缓解资源紧张现象,是利国利民的好途径。 相似文献
178.
云南个旧多金属矿区农田土壤-作物系统重金属污染现状——以乍甸镇为例 总被引:7,自引:0,他引:7
对云南个旧市乍甸镇农田土壤和农作物重金属污染现状进行了野外调查及评价。结果表明:农田土壤Pb、Zn、Cu、Cd、As质量比均超出GB 15618—1995《土壤环境质量标准》二级标准,Hg未检出,该地区农田呈现以As、Cd为主多种重金属复合污染。Pb、Zn、Cu、Cd、As土壤有效态质量比与土壤全量呈极显著正相关(p<0.01)。农作物中Cu、As质量比与土壤有效态Cu、As质量比无显著相关,Zn质量比与土壤有效态Zn呈极显著负相关(p<0.01),Cd、Pb质量比与土壤有效态Cd、Pb呈显著正相关(p<0.05)。89%的农作物As超标,油菜籽(Brassica napusL.)As质量比最高,均值达(23.04±14.33)mg/kg(鲜重,下同)。Pb超标率达72%,油菜籽Pb质量比最高,平均为(5.55±2.53)mg/kg。Zn、Cd超标率均为11.11%,超标最严重的油菜籽Zn质量比为(46.65±13.61)mg/kg,Cd质量比为(0.24±0.10)mg/kg。Cu超标率为5.55%,油菜籽Cu质量比最高,达(16.02±2.75)mg/kg。油菜籽对As、Pb、Zn、Cu、Cd的转移系数(农作物可食部分重金属质量比(鲜重)与土壤重金属质量比的比值)远高于其他作物。农作物对Pb、Zn、Cd、As的转移顺序依次为果实类、叶菜类、根茎类,对Cu的转移顺序为果实类、根茎类、叶菜类。农作物以As、Pb污染为主,总体属重度污染。聚类分析得出:油菜籽、青蒜(Allium ampeloprasumL.)和生菜(Lactuca sativaL.var.ramosaHort.)重金属污染严重,不适合在该地区继续种植和食用。 相似文献
179.
食物波动与效率是食物安全的重要研究内容。1993~2003年江西省平均食物生产全要素相对生产率为0.974,其规模效益基本上呈现常数规模效益与规模效益递增交替波动现象。灰色关联分析表明,粮食产量、油料产量、肉类产量、糖料产量等与食物总量具有显著关联性,其灰色关联序为:粮食产量>油料产量>肉类产量>糖料产量>禽蛋产量>水果产量>牛奶产量,所以要保证食物总量安全,必须首先保障粮食、油料、肉类等的生产。 相似文献
180.