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201.
在剖析了V.keilia-Borok研究小组近年来提出的强震预报(Time of increasedprobability)方法的基础上,本文简要地介绍了该方法的原理,采用1970-01-01至1991-12-31的全国地震目录,通过两种途径,用Tip方法对云南省和台湾省发生的7级以上(含7级)强震做了检验地震目录,通过表明Tip方法对强震的预报成功率还是较高的.在此基础上,我们又试验将该方法推广应用于云南省发生的6.5级以上(含6.5级)地震,结果表明适当修改地震流函数后,也可以得到较满意的结果. 相似文献
202.
Structure of flames propagating through aluminum particles cloud and combustion process of particles 总被引:5,自引:0,他引:5
Jinhua Sun Ritsu Dobashi Toshisuke Hirano 《Journal of Loss Prevention in the Process Industries》2006,19(6):769-773
Structure of flames propagating through aluminum particles clouds and combustion processes of the particles have been examined experimentally to understand the fundamental behavior of a metal dust explosion. The combustion process of individual aluminum particles in a flame propagating through the aluminum particles cloud has been recorded by using a high-speed video camera with a microscopic optical system, and analyzed. The flame is shown to be consisted of a preheat zone of about 3 mm thick, followed by a combustion zone of 5–7 mm thick. In the combustion zone, discrete gas phase flames are observed around each aluminum particle. Also an asymmetric flame around a particle is observed, which might be caused by an ejection of aluminum vapor from a crack of oxide shell surrounding the particle. 相似文献
203.
We measured 39 polybrominated diphenyl ethers (PBDEs) in the muscle tissue of three species of fish (Sciaenops ocellatus, Sparus
macrocephalus, and Lateolabrax japonicus) and four species of shellfish (Tegillarca granosa, Cyclina sinensis, Sinonovacula constricta,
and Ostrea cucullata) that were collected downstream of electronic-waste recycling plants in Taizhou, China. A total of 24 PBDE
congeners (PBDE24) in the samples were detected. The PPBDE24 (total PBDE) ranged from 545.4 to 1688.7 ng/kg ww (wet weight).
The mean PPBDE24 concentration was 1382.6 ng/kg ww in fish and 858.1 ng/kg ww in shellfish. The lower brominated congeners
were detected at relatively high concentrations in all species. The penta-products, produced from e-waste, were found at relatively low
levels. A principal component analysis suggested a significant correlation among di-, tri-, tetra-, and hepta-BDEs for the three species of
fish. Similarly, we found a significant correlation between mono- and tri-BDEs in the shellfish. Our results suggested that the processes
of PBDE metabolism and elimination were similar in both fish and shellfish. In addition, the primary source of PBDEs appeared to be
from the debromination of high brominated PBDEs. 相似文献
204.
<正>森林乃维护自然界生态平衡、调节大气、净化环境的重要可持续资源。东南亚林业大国缅旬多年来在推动林木经济发展同时,尽力实对林业资源的可再生保护。迄今为止,该国已逐渐形成由现行《缅甸联邦森 相似文献
205.
Biogenic silica (BSi) contents in the marsh plants (Phragmites australis, Scirpus mariqueter and Spartina alterniflora) and associated
sediments in Chongming Island eastern intertidal flat of the Yangtze Estuary were determined. The BSi contents in P. australis, S.
mariqueter and S. alterniflora varied from 25.78–42.74 mg/g, 5.71–19.53 mg/g and 6.71–8.92 mg/g, respectively. Over the entire
growth season, P. australis and S. mariqueter were characterized by linear accumulation patterns of BSi. The aboveground biomass
(leaves and culms) of the marsh plants generally contained more BSi than underground biomass (roots). BSi contents were relatively
higher in dead plant tissues than in live tissues which was probably due to the decomposition and the leaching of labile components
of plant tissues such as organic carbon and nitrogen. Comparing with the habitats of S. mariqueter and S. alterniflora, the highest BSi
content was recorded in sediments inhabited by P. australis, with an annual average of 15.69 mg/g. Overall, the intertidal marshes in
the Yangtze Estuary may act as a net sink of BSi via plant uptake and sedimentary burial. 相似文献
206.
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208.
循环经济是一种以提高生态效率为核心、以遵循3R技术为原则、以两低一高为基本特征、符合可持续发展理念的经济增长模式.推行循环经济是实现社会-经济-环境系统可持续发展的必由之路.通过阐述循环经济内涵,并就长沙环境质量、资源供需情况、农业发展等方面作了分析,并且分析了长沙推行循环经济可能面临的问题,提出发展循环经济是长沙新的发展经济模式和实现经济、社会、环境协调发展的战略选择,并就此提出了建议. 相似文献
209.
分析了泥沙含量对总氮测定结果的干扰影响,结果表明:水样中泥沙的含量与其对水样总氮的贡献有显著的正相关性;泥沙对总氮测定结果有干扰影响,随泥沙含量增加,A275的测定值及总氮降低率逐渐增大,且当泥沙(SS)含量≥45 mg/L时,其A275/A220的值在20%以上,总氮降低率在15%以上,从而总氮测定值产生较大的误差。消解后离心法或消解后0.45μm滤膜过滤法能有效地消除泥沙的干扰,并均具有操作简单和准确度高的优点。 相似文献
210.
Ying Xue Keke Xiao Xiang Wu Mei Sun Yifei Liu Bei Ou Jiakuan Yang 《Frontiers of Environmental Science & Engineering》2023,17(3):35