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161.
于瑞莲  赵元慧 《环境化学》1998,17(5):451-456
测定了24个取代苯胺和苯酚类化合物在不同PH下对大型蚤的24h半数抑制浓度24h-IC50。结果表明,苯胺类的毒性随PH的升高而增大,酚类的毒性随PH的升高而减小。  相似文献   
162.
研究了苯胺与甲基苯胺对大型溞(Daphnia magna)的单一毒性及二元混合物的联合毒性,采用相加指数法(AI)和混合毒性指数法(MTI)进行评价,结果均为协同作用,并进一步证明混合物的配比对评价结果有一定的影响。  相似文献   
163.
以城市综合污水处理厂污泥的浸提液对Daphnia magna的24h急性毒性为指标,研究了污泥放置时间与其毒性的关系。结果表明,污泥对Daphnia magna的急性毒性随旋转时间的增加逐渐增大,但在旋转两个月后毒性趋于稳定。对放置3d和84d的污泥,利用TIE(毒性鉴别评价)方法对其浸提液进行了毒物特性鉴别,结果表明,放置3d的污泥,浸提液毒性主要由酸性条件下易挥发的物质引起,放置84d的污泥浸提液中的毒物主要为金属离子和易与酸碱反应的物质。  相似文献   
164.
Galassi S  Guzzella L  Croce V 《Chemosphere》2004,54(11):1619-1624
Complex mixtures of toxic substances occurring in surface waters are difficult to characterise by chemical analyses because each compound occurs at a very low concentration and requires a specific analytical method to be identified. Ecotoxicological tests on water extracts can be used as a screening tool to evaluate quickly and simply the overall quality of a water body with regard to micropollutant contamination. In this work, a pre-concentration procedure based on solid-phase extraction (SPE), suitable for both biological testing and analytical determination, is proposed. The extraction procedure is an improved version of a methodology used to evaluate the toxicity of organic micropollutants occurring in surface waters. It offers the advantage of using disposable commercial cartridges, which are easier to manage than the columns prepared with macromolecular resins. Water extracts from two representative Italian rivers, characterised by a different gradient of potential contamination and prepared according to the new concentration techniques, are used. The acute toxicity of the water extracts is tested on Daphnia magna and the bioluminescence inhibition in Vibrio fischeri. Criteria based on the concentration factor (CF) are proposed for assessing the hazard to aquatic life due to the exposure to toxic substances in surface waters. The aim of hazard ranking is to focus analytical efforts towards those samples that show the highest toxic potential.  相似文献   
165.
有机毒物对水蚤的急性毒性   总被引:4,自引:0,他引:4  
刘征涛  金琼贝 《环境化学》1994,13(3):263-265
对水蚤的毒笥试验数据是被广泛用于评价化合物水生生态效应的重要依据,检测有机化合物的毒性时,需特别注意待测物的难溶性,挥发性及易光解性,检测了多种氯代芳烃的EC50值,其18h的结果与24h的结果相近,检测了24种硝基芳烃的毒性,不同方法计算的EC50值一致。  相似文献   
166.
The possibility of symbiotic, mutualistic (++) interrelations between epibiontic microalgae (Characidiopsis ellipsoidea, Colacium vesiculosum) and cyclopoids (Cyclops vicinus, Mesocyclops leukarti) in the Bugach recreational reservoir with a bloom of cyanobacteria is demonstrated. Overgrown cyclopoids, compared to those free from microalgae, have advantages in oxygen supply, which may be insufficient in the period of intensive algal bloom. Calculations have shown that oxygen requirements of cyclopoids may be fully satisfied due to C. vesiculosum photosynthetic activity in the dysphotic zone if the density of overgrowth exceeds 1000 algal cells per individual. There is no significant correlation between the natural mortality of crustaceans and the indices of their overgrowth by microalgae.  相似文献   
167.
以实验室培养的大型潘为受试生物,参照OECD推荐的化学品对水生生物的标准试验方法,测定了普萘洛尔(PRO)母液及其光解产物对大型溞的急性毒性和21 d慢性毒性,综合评价二者对大型溞的生长繁殖毒性效应.结果表明,PRO母液对大型溞的24 h-LC50和48 h-LC50分别为5.88 mg/L和4.91 mg/L,属高毒物质.PRO对大型溞的安全质量浓度为0.86 mg/L.21 d慢性毒性结果显示,PRO母液对母潘的产溞时间、产溞量、产溞胎数都有显著影响,且效果随PRO质量浓度增加而增加.大型溞F1 (1st)和F1 (3rd)代在恢复条件下的产溞时间无明显影响,但产溞量显著下降.通过GC/MS鉴定,PRO在光解过程中产生5种低相对分子质量有机物,包括萘、萘酚及邻苯二甲酸酐等.随光解时间延长,PRO光解溶液的毒性下降,其对大型溞的毒性效应是PRO母液及其光解产物共同作用的结果.  相似文献   
168.
Cadmium and chlordane are compounds chosen for a preliminary study on the impact of environmental contaminants on apoptosis in different representative species. These two potentially toxic substances decrease in vitro apoptosis of Daphnia magna cells. This appears to be related to the chemical concentrations and the time exposure. Cadmium was also directly introduced to the cell culture medium of Syrian hamster embryos (SHE) or indirectly via daphnids, which had firstly consumed algae contaminated with cadmium. A very sharp transfer of cadmium toxicity from algae to daphnids is noted and an inhibition of the apoptosis in SHE cells can be observed.  相似文献   
169.
利用RAPD(随机扩增多态)标记分析湖内鲤、鲫群体遗传多样性,从40个随机引物中各筛选出8个引物适合鲤、鲫群体RAPD扩增。在鲤群体中,共检测出60条带,其中多态性带42条,多态位点比率为70.00%;而在鲫群体中,共检测出61条带,其中多态性带40条,多态位点比率为65.57%。用POPGENE软件分析实验数据,结果显示:湖内鲤群体的遗传多样性水平(He=0.230 1,H0=0.391 0)和鲫群体的遗传多样性水平(He=0.218 6,H0=0.375 8)都较高,都有较大的遗传变异。而在鲤、鲫群体内,雌性群体与雄性群体相比较,其各自的遗传多样性很接近。  相似文献   
170.
A single dose of an extract from 16 and 5 grams fly ash was administered orally to male rats and hamsters. In the rat 1,2,3,7,8‐PnCDD had the highest retention (41%) in the liver. The congener with the highest retention in the liver of the hamster was 2,3,4,7,8‐PnCDF (70.9%). In two oral multiple dose experiments with rats, highest liver retentions were found for 1,2,3,7,8‐PnCDD (51.7%) and 1,2,3,6,7,8‐HxCDD (59.8%). With the exception of 2,3,4,6,7‐PnCDF, all PCDDs and PCDFs retained in the liver of rat and hamster had a 2,3,7,8 chlorine substitution pattern. In both types of experiments with rats the retention of 2,3,7,8‐TCDF in the liver was very low, 1.1–2.8% of the total dose. In the liver of the hamster retention of 2,3,7,8‐TCDF was almost equal to that of 2,3,7,8‐TCDD, indicating that the hamster is probably metabolizing 2,3,7,8‐TCDF Jess efficiently than the rat. In all experiments 1,2,3,7,8‐PnCDD and 2,3,4,7,8‐PnCDF were retained in the liver more efficiently than 2,3,7,8‐TCDD. Based on first order pharmacokinetic calculations, it was found that the earlier published ke value of 0.55 for 2,3,7,8‐TCDF in the liver of the rat was also applicable. Using the same calculations for 2,3,7,8‐TCDD (ke = 0.029) a 30% difference was found between calculated and actual measurements, but calculated results were still within the 95% confidence limits of the actual measurements.  相似文献   
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