首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   87篇
  免费   1篇
  国内免费   1篇
安全科学   9篇
废物处理   2篇
环保管理   4篇
综合类   5篇
基础理论   8篇
污染及防治   42篇
评价与监测   10篇
社会与环境   8篇
灾害及防治   1篇
  2023年   3篇
  2022年   1篇
  2021年   3篇
  2019年   2篇
  2018年   5篇
  2017年   5篇
  2016年   4篇
  2015年   1篇
  2014年   4篇
  2013年   18篇
  2012年   3篇
  2011年   6篇
  2010年   1篇
  2009年   2篇
  2008年   3篇
  2007年   1篇
  2006年   3篇
  2005年   3篇
  2004年   2篇
  2003年   6篇
  2002年   4篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1996年   1篇
  1992年   1篇
  1964年   1篇
  1931年   1篇
排序方式: 共有89条查询结果,搜索用时 15 毫秒
61.
High-resolution digital photography and graphical image analyses systems have been used to define external morphometric characters of shell deformations in four populations of the Baltic clam Macoma balthica from the Gulf of Gdansk (southern Baltic Sea). The proposed shell deformation indices (SDI), which were based on the relationship of selected dimensions in the posterior and the anterior part of the shell, showed at least three morphological features that provide a distinctive diagnosis of "regular" and "deformed" clams: the presence of flexure on the posterior side (SDI1), elongated posterior region (SDI2), and shell growth (SDI3). The degree and prevalence of deformed clams varied locally over space. Increase in percentage contribution of aberrated shells with depth, corresponding to oxygen depletion profile in the Gulf, suggests low oxygen concentrations as the main agent exerting a deforming influence. The observed morphological aberrations developed with age (size) of a bivalve, suggesting a long-term effect of causal factors, and were accompanied by lightening shell weight, possibly due to decalcification of previously deposited calcareous material during anaerobic metabolism. It is hypothesized that hypoxic/anoxic conditions and a subsequent presence of hydrogen sulfide on a deep organic-rich sea bottom induce shell form alterations that enable the pumping of oxygenated water from above the anoxic layer. Such a morphological modification highlights the functional significance of shell deformations in protective response to the ambient low-oxygen concentrations. Sediment organotin concentrations fall within moderate to high contamination range and, therefore, may also have an adverse impact on the shell form. DNA analyses of the fragment of mitochondrial gene cytochrome oxidase I (COI, 393 base pairs) showed homogenous genetic structure of regular and deformed clams, indicating that shell deformations in M. balthica are primarily driven by acclimatization to the ambient environmental conditions.  相似文献   
62.
Concentrations of Al, B, Ba, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Se, Si, Sr, Tl, V, Zn, Ca, K, Mg, Na and P in the livers of marine mammals obtained from by-catches or stranded on beaches on the Polish Baltic coast were determined by ICP-MS or ICP-AES and CV AAS. Interspecific diversity with respect to the contents of these elements was found in cetaceans and pinnipeds. The diverse Cd contents in the livers of these mammals can be attributed to the variable concentrations of this element in their food. Mercury was correlated with age and can reach high concentration associated with higher level of Se in older specimens. No significant relationships were found between concentration of the chemical elements studied and nutritional status/condition of the Baltic harbour porpoises as well as between their concentration in specimens from the Gulf of Gdańsk and open Baltic. It seems that the nutritional and health status of the specimens studied is generally enough good since the specimens studied were not stranded on beach because of starvation but almost incidentally caught in salmon gill nets. Strong correlations were found between the macroelements analysed, i.e. for the Ba-Ca-Sr, Ca-K, Ca-Mg, Mg-P, Zn-Mg and Zn-P assemblies. Significantly higher content of Al was found in males of harbour porpoises.  相似文献   
63.
Environmental Science and Pollution Research - Due to the limited studies dealing with isotopes levels in benthic macroinvertebrates other than Mytilus sp. in period 2011–2018,...  相似文献   
64.
We studied the effect of chlorfenvinphos dermal absorption on the morphological picture of blood, on the histological and fine structure of tail skin, and on the histological structure of internal organs (lungs, heart, liver, spleen, and kidney) of rats. This study was conducted on 25 white Wistar rats, the tail skin of which was—or was not—hydrated before exposure. Rat tails were soaked in 0.5% or 0.05% chlorfenvinphos for 1 hr day for 3 months. Evident tendencies for a decrease in the absolute level of leukocytes and for an increase in the absolute level of erythrocytes in all experimental animals were observed. Histopathological changes in the internal organs were mildly manifested in only a few rats, mainly as liver and pulmonary hyperaemia. Rat tail skin at the direct exposure site showed hyperceratosis, intensive desquamation, and compensatory hyperplasia.  相似文献   
65.
Air pollutants emitted while processing phenol-formaldehyde resins have been investigated. Gas chromatography-mass-selective detection was used to separate and identify chemical compounds. It was determined that workers were exposed to formaldehyde in all workplaces. Besides, phenol, acetaldehyde, acrylaldehyde, 2-furaldehyde, xylene, ethylbenzene, toluene, tetrachlorethene, ethyl acetate, butyl acetate were found during the production of frictional materials; and 2-furaldehyde, phenol, naphthalene, 2-furan-methanol, polycyclic aromatic hydrocarbons (PAHs) during the production of abrasive materials. Quantitative analyses were performed with gas chromatogra-phy and high performance liquid chromatography. Assessment of occupational exposure indicated that chemical compounds emitted during the investigated processes might be dangerous for human health, mainly because of suspected carcinogenic compounds: formaldehyde and PAHs.  相似文献   
66.
This paper presents the concept of active variable thermoinsulation clothing for users working in low temperatures. Those garments contain heating inserts regulated by a microprocessor temperature controller. This paper also presents the results of tests carried out on the newly designed garments.  相似文献   
67.
Lead levels in wet and dry deposition were determined within this project. A network of 10 sampling stations was established. The stations were located in areas characterized by heavy traffic volumes, but away from industrial and/or municipal pollution sources. It was assumed, therefore, that lead in the samples collected was coming primarily from automobile emissions. Measurements were carried out over a period of one year. Both rain and snow samples were collected. Lead concentrations in the samples ranged from 0.6 to 141 microg dm(-3). They depended on street topography, traffic volume, average speed of the vehicles, frequency of traffic congestion and atmospheric conditions. The highest lead levels in deposition were observed during the cold season.  相似文献   
68.
The article presents the results of screening research on acute toxicity of groundwater contaminated by leachates to the bacterium Vibrio fischeri (ToxAlert 100® test) and crustacean Daphnia magna (Daphtoxkit F? magna test according to PN-EN ISO 6341), as well as on chronic toxicity to D. magna (test according to ISO 10706). The groundwater samples were taken from seven large city landfills in the Pomeranian province (Poland), which were open before 1990 and designed without proper attention to being leak-tight. Due to the lack of either European or Polish classification of ecotoxicological qualities of surface and underground waters, an attempt was made to evaluate the ecotoxicological quality of the examined waters on the basis of the Helsinki Committee's recommendations for industrial effluents, the classification of sediment according to Krebs (Krebs F. The pT-value as a classification index in aquatic toxicology. GIT Edition Umweltanalytik-Umweltschutz 1988;1:57–63) and the classification system of toxicity levels for natural waters and sewers, recently proposed by Persoone et al. (Persoone G, Marsalek B, Blinova, I, Törökne A, Zarina D, Manusadzianas L, Nalecz-Jawecki G, Tofan L, Stepanova N, Tothova L, Kolar B. A practical and user-friendly toxicity classification system with microbiotests for natural waters and wastewaters. Environ. Toxicol. 2003;18 (6):395-402).  相似文献   
69.
In contaminated soils, excessive concentrations of metals and their high mobility pose a serious environmental risk. A suitable soil amendment can minimize the negative effect of metals in soil. This study investigated the effect of different biochars on metal (Cu, Pb, Zn) immobilization in industrial soil. Biochars produced at 300 and 600 °C from conventional (MS, maize silage; WP, wooden pellets) and alternative (SC, sewage sludge compost; DR, digestate residue) feedstocks were used as soil amendments at a dosage of 10 % (w/w). The type of feedstock and pyrolysis temperature affected the properties of the biochars and their ability to immobilize metal in soil. Compared to production at 300 °C, all biochars produced at 600 °C had higher pH (6.2–10.7), content of ash (7.2–69.0 %) and fixed carbon (21.1–56.7 %), but lower content of volatile matter (9.7–37.2 %). All biochars except DR biochar had lower dissolved organic carbon (DOC) content (1.4–2.3 g C/L) when made at 600 °C. Only MS and SC biochars had higher cation exchange capacity (25.2 and 44.7 cmol/kg, respectively) after charring at 600 °C. All biochars contained low concentrations of Cd, Cu, Ni, Pb and Zn; Cd was volatilized to the greatest extent during pyrolysis. Based on FTIR analysis and molar ratios of H/C and O/C, biochars had a greater degree of carbonization and aromaticity after charring at 600 °C. The efficiency of the biochars in metal immobilization depended mainly on their pH, ash content, and concentration of DOC. SC and DR biochars were more effective for Cu and Zn immobilization than MS and WP biochars, which makes them attractive options for large-scale soil amendment.  相似文献   
70.

The present study determines the influence of three ionic liquids (ILs) containing cations with diversified structure on the growth and development of spring barley seedlings and common radish leaves. Increasing amounts of 1-butyl-1-methylpyrrolidinium hexafluorophosphate [Pyrrol][PF6], 1-butyl-1-methylpiperidinium hexafluorophosphate [Piper][PF6], and 1-butyl-4-methylpyridinium hexafluorophosphate [Pyrid][PF6] were added to the soil on which both plants were cultivated. The results of this studies showed that the applied ILs were highly toxic for plants, demonstrated by the inhibition of length of plant shoots and roots, decrease of fresh mass, and increase of dry weight content. Common radish turned out to be the plant with higher resistance to the used ILs. The differences in the cation structure did not influence phytotoxity of ILs for spring barley. Furthermore, all ILs led to a decrease of photosynthetic pigments, which was directly followed by decreased primary production in plants. Oxidative stress in plants occurred due to the presence of ILs in the soil, which was demonstrated by the increase of malondialdehyde (MDA) content, changes in the H2O2 level, and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). The changes in the chlorophyll contents and the increase of POD activity turned out to be the most significant oxidative stress biomarkers in spring barley and common radish. Both spring barley and radish exposed to ILs accumulated a large amount of fluoride ion.

  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号