全文获取类型
收费全文 | 197篇 |
免费 | 1篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 16篇 |
环保管理 | 26篇 |
综合类 | 12篇 |
基础理论 | 29篇 |
污染及防治 | 76篇 |
评价与监测 | 27篇 |
社会与环境 | 9篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 17篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 21篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 4篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有202条查询结果,搜索用时 31 毫秒
61.
62.
Insect immunology is an active research arena, however, the vast majority of research in the area is conducted on model species
taken from laboratory cultures. We tested the hypothesis that insects are regularly exposed to infections or invasions in
nature and here report results of a field study designed to assess the extent of natural infections in insects collected from
agrarian fields surrounding Kahramanmaraş, Turkey. Specimens were dissected to assess numbers of nodules. Formation of darkened,
melanotic nodules is the predominant cellular immune reaction to microbial and parasitic infection, and once formed, the nodules
are permanently attached to internal surfaces. The collected insects were healthy. Of the >400 examined specimens, at least
some nodules were found in 98%. Numbers of nodules ranged from ∼2/individual to >100 nodules/individual. We conclude that
insects are regularly challenged by microbial and parasitic infections from which they recover. The novel implication of our
data is that insect immune systems may limit the host range and effectiveness of agents deployed in biological control programs.
Knowledge of insect immune systems may contribute to increased use of biopesticides globally. 相似文献
63.
Apaydın Aylin Kabaoğlu Hatice Apaydın Gökhan Şirin Murat Cengiz Erhan Köksal Oğuz Kağan Baltaş Hasan Tıraşoğlu Engin 《Environmental science and pollution research international》2022,29(5):7053-7066
Environmental Science and Pollution Research - In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling... 相似文献
64.
Hasan Md. Sabbir Al Foisal Jannat Khan G. M. Arifuzzaman Jahan Rownok Hasanuzzaman Md. Alam Md. Shamsul Karim M. Minnatul Gafur M. A. Khan Muhammad Angkan Sabur Md. Abdus 《Journal of Polymers and the Environment》2022,30(7):2875-2887
Journal of Polymers and the Environment - Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a... 相似文献
65.
This study was conducted in river Panjkora (Khall, upstream; Timergara, downstream) and its tributary (Konhaye stream, reference site) at district Lower Dir. The study was aimed to assess heavy metal load in gills, liver, kidneys, and muscles of three fish species, namely Schizothorax esocinus, Racoma labiata, and Crossocheilus diplocheilus. The heavy metals, including nickel, cadmium, lead, copper, zinc, chromium, iron, and manganese were determined using an atomic absorption spect-rophotometer. Nickel and cadmium were not detected in any of the collected specimens at all sampling sites. Concentration of the detected metals varied significantly depending upon fish species and tissue type. Crossocheilus diplocheilus showed higher accumulated concentration of heavy metals while R. labiata contained the least. Schizothorax esocinus and R. labiata displayed significant differences in their concentrations of metals. The order of accumulation of heavy metals in different tissues was liver>kidneys>muscles>gills. Data demonstrated that heavy metal levels in the studied species were within permissible limits and thus, apparently suitable for human consumption. Currently, the river contains a sewage burden, and continued heavy pollution may ultimately lead to serious problems in the future. 相似文献
66.
Rheological Investigation of Wood-Polypropylene Composites in Rotational Plate Rheometer 总被引:1,自引:0,他引:1
Ehsan Soury Amir Hossein Behravesh Ghaus M. Rizvi Nathan Jafarian Jam 《Journal of Polymers and the Environment》2012,20(4):998-1006
In this research work, the rheological properties of Wood-Plastic Composites (WPC) with some selected compositions are investigated. WPC is being recognized as a green composite that, in the past 20?years, has emerged to a commercial product. A study on rheological properties of these materials can give insight into the proper selection of composition and processing condition. Two grades of polypropylene (PP) with two different melt flow indexes (MFI) were selected to prepare WPCs with three different wood contents (50, 60 and 70?% wt.). Four types of rheological experiments were performed utilizing a rotational plate rheometer: (1) strain sweep, (2) frequency sweep, (3) temperature sweep and (4) steady shear rate sweep. The independent variables were chosen as wood content, MFI of polymer (two types), melt temperature, frequency or shear rate, the gap between the plates, and strain percentage. The strain sweep tests specified the linear and non-linear viscoelastic zones of each experiment. The results of frequency sweep experiments indicated that increasing the wood content and frequency and also decreasing the strain percentage and the gap distance, lead to an increase in the storage modulus. Regarding the loss modulus, wood percentage and the gap distance presented positive effects and strain percentage showed a negative effect. The behavior of complex viscosity was almost similar to that of the storage modulus but increasing the frequency caused a decrease in the complex viscosity. In case of temperature sweep experiments, it was observed that the rheological properties exhibit a rapid change near to a temperature of 160?°C. The results also showed that beyond this point, increasing the wood content and also MFI of polypropylene caused an increase in the storage modulus. The results of steady shear rate sweep experiments specified that increasing wood content and also decreasing the MFI of PP, the gap distance and shear rate lead to an increase in both viscosity and shear stress. 相似文献
67.
Mut Z Aydin N Bayramoglu HO Ozcan H 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(4):489-495
This study was carried out in order to determine some quality traits such as thousand grain weight (TGW), hectoliter weight (HW), grain protein content (GPC), Zeleny sedimentation volume (ZSV) and stability of quality traits of 25 bread wheat genotypes. The experiment was conducted at seven environmental conditions during 2 growing periods (2003-2004 and 2004-2005) using randomized complete block design with four replicates. The ANOVA showed that out of the total sum of squares, 48.4, 28.0 and 23.6% for TGW, 71.4, 14.9 and 13.7% for HW, 54.4, 23.0 and 22.6% for GPC, 44.7, 41.7 and 13.6% for ZSV was attributable to E, G and G x E interaction effects, respectively. Thousand grain weight, hectoliter weight, grain protein content and Zeleny sedimentasyon volume of genotypes changed from 34.5 to 41.4 g, from 76.5 to 80.4 Kg, from 11.49 to 13.37% and from 22.1 to 46.0 ml, respectively. Seven stability parameters, covering a wide range of statistical approaches, were used so as to predict the genotypes. The study of genotypic stability showed that Bezostaya and advanced lines numbered 11 and 24 had high stability for quality traits and proved to be the best within the pool of the studied genotypes. Also, 8 and 17 numbered genotypes demonstrated high stability for TGW, HW, GPC and HW, GPC and ZSV, respectively. 相似文献
68.
Ashraf Muhammad Aqeel Faheem Muhammad 《Environmental science and pollution research international》2020,27(30):37173-37175
Environmental Science and Pollution Research - 相似文献
69.
A. Rasem Hasan Ligang Hu Lynne Fieber Timothy G. Townsend 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1479-2604
Earlier studies documented the loss of wood preservatives from new wood. The objective of this study was to evaluate losses from weathered treated wood under field conditions by collecting rainfall leachate from 5 different wood types, all with a surface area of 0.21 m2. Wood samples included weathered chromate copper arsenate (CCA) treated wood at low (2.7 kg/m3), medium (4.8 kg/m3) and high (35.4 kg/m3) retention levels, new alkaline copper quat (ACQ) treated wood (1.1 kg/m3 as CuO) and new untreated wood. Arsenic was found to leach at a higher rate (100 mg in 1 year for low retention) than chromium and copper (<40 mg) in all CCA-treated wood samples. Copper leached at the highest rate from the ACQ sample (670 mg). Overall results suggest that metals' leaching is a continuous process driven by rainfall, and that the mechanism of release from the wood matrix changes as wood weathers. 相似文献
70.
Brassinosteroids protect photosynthetic machinery against the cadmium induced oxidative stress in two tomato cultivars 总被引:2,自引:0,他引:2
The present study was conducted with an aim to gain better insight of brassinosteroid generated response on the effects of cadmium on photosynthetic machinery and active oxygen metabolism in two tomato cultivars (K-25 and Sarvodya). These tomato cultivars were subjected to graded cadmium levels in soil (0, 3, 6, 9 or 12 mg kg−1 soil) with their foliage being sprayed with 0 or 10−8 M of 28-homobrassinolide/24-epibrassinolide (HBL/EBL) at 59 d stage. The results suggested that photosynthetic parameters, leaf water potential and activity of several enzymes (nitrate reductase and carbonic anhydrase) decreased significantly in both the cultivars, to a lesser extent in K-25 than Sarvodya with the increasing levels of cadmium in the soil. However, the activity of antioxidant enzymes and proline content increased in response to metal treatment as well as the application of brassinosteroids (HBL/EBL). Overall, exogenous application of brassinosteroids improved the activity of photosynthetic machinery and that of antioxidant defense system in both the cultivars, and also nullified the damaging effect of metal on these parameters. 相似文献