全文获取类型
收费全文 | 446篇 |
免费 | 1篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 37篇 |
环保管理 | 14篇 |
综合类 | 72篇 |
基础理论 | 101篇 |
污染及防治 | 147篇 |
评价与监测 | 53篇 |
社会与环境 | 14篇 |
出版年
2023年 | 6篇 |
2022年 | 18篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 21篇 |
2017年 | 18篇 |
2016年 | 27篇 |
2015年 | 14篇 |
2014年 | 33篇 |
2013年 | 62篇 |
2012年 | 27篇 |
2011年 | 31篇 |
2010年 | 26篇 |
2009年 | 18篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 6篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 4篇 |
1966年 | 3篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1961年 | 2篇 |
1960年 | 5篇 |
1959年 | 5篇 |
1958年 | 10篇 |
1957年 | 4篇 |
1956年 | 3篇 |
1955年 | 1篇 |
1931年 | 1篇 |
1930年 | 1篇 |
排序方式: 共有447条查询结果,搜索用时 109 毫秒
181.
182.
183.
184.
185.
Vosyliene MZ Kazlauskiene N Svecevicius G 《Environmental science and pollution research international》2003,10(2):103-107
The effects of a model mixture (HMMM) of seven heavy metals (Cu, Zn, Ni, Cr, Pb, Cd, Mn) on the rainbow trout Oncorhynchus mykiss at all stages of development (embryos, larvae, adults) were investigated based on the annual average concentrations of these metals in cooling waste waters discharging from Ignalina Nuclear Power Plant (Lithuania) into the Drūk?iai lake. According to mortality parameters, the most sensitive to HMMM were larvae, although no significant differences between the sensitivity of embryos and adult fish to HMMM were found. Maximal toxic effect of HMMM was observed during the hatching period. Long-term exposure to sublethal concentrations of HMMM affected embryo development, growth of larvae, their cardio-respiratory and behavioural responses, induced significant changes in morphological, morpho-physiological, physiological and haematological parameters of adult fish. Respiratory responses and growth parameters of fish were found to be the most sensitive to low concentrations of HMMM. Adult fish were capable of detecting and avoiding low, sublethal concentrations of HMMM. Heavy metals in a mixture at low concentrations were more toxic than single ones. According to the background of the damages induced by HMMM, after-effects in a fish organism, as well as in a whole population, can be predicted. 相似文献
186.
In the period from 1980 to 1984 organic phosphorus, nutrients, primary production rates (14C), chlorophyll a (chl a) standing crops, and basic oceanographic parameters were measured during 23 cruises at six stations in the open waters of the northern Adriatic Sea. These waters are significantly influenced by polluted Po River discharge. Organic phosphorus was correlated with several parameters which characterize phytoplankton activity and organic matter decomposition processes. In the late winter-spring period, organic phosphorus is produced during phytoplankton blooms. It is hypothesized that microzooplankton grazing is the main factor increasing the organic phosphorus concentrations in summer (up to 1.1 mol 1-1). Fall and winter had much lower values (below 0.3 mol 1-1) due to remineralization processes and an increased water mass exchange between the northern and central Adriatic regions. The direct contribution of organic phosphorus by freshwater discharge was not found to be significant. The higher organic phosphorus concentrations that can occur in low salinity waters are most likely due to their increased capability to support primary production. 相似文献
187.
The relationship between somatic growth and growth of otoliths of sea bass larvae, postlarvae and juveniles under relatively steady temperature conditions was studied. Larvae were incubated at the constant ambient temperature of 13.5°C, whereas postlarvae and juveniles were reared at a comparatively steady temperature ranging from 18.6 to 20.4°C, with a mean of 19.67°C. The patterns of both somatic and otolith growth were found to be similar. Differentiated data on larvae length and otolith diameters indicated three periods of change in their growth rates. Since temperature was kept relatively steady during the experiment, and larvae fed ad libitum, these periods could be attributed with relative certainty to intrinsic changes which occur during stage-specific periods of growth. The third period of change in both growth rates indicates a specific phase of growth during metamorphosis. The changes in growth rates, as well as the raw time series of the growth of both larval lengths and otolith diameters, may be described by higher order polynomials with a high degree of probability levels. A non-linear relationship between body length and otolith diameters was established, indicating positive allometric growth of otoliths. It was also observed that the coefficient of allometric growth changed at the time estimated for the end of metamorphosis. Thus, a non-linear relationship and changes in the coefficients of allometry should be borne in mind when back-calculating somatic growth from the growth of otoliths. 相似文献
188.
M. Peharda C. A. Richardson I. Mladineo S. Šestanović Z. Popović J. Bolotin N. Vrgoč 《Marine Biology》2007,151(2):629-638
Age, growth and population structure of Modiolus barbatus from Mali Ston Bay, Croatia were determined using modal size (age) classes in length frequency distributions, annual pallial
line scars on the inner shell surface, internal annual growth lines in shell sections of the middle nacreous layer and Calcein
marked and transplanted mussels. The length frequency distributions indicated that M. barbatus attain a length of ∼40 mm in 5–6 years indicating that a large proportion of the population in Mali Ston Bay is <5 years
old. Some mussels of ∼60 mm were predicted to be 14 years old using the Von Bertalanffy growth (VBG) equation. Up to the first
6 pallial line scars were visible in young (<6 years) mussels but in older shells the first scars became obscured by nacre
deposition as the mussel increased in length and age. The age of the older shells (>6 years) was determined from the middle
nacreous lines in shell section, which formed annually in winter between February and March; the wider dark increments forming
during summer (June to September). The oldest mussel, determined from the middle nacreous lines, was >12 years, with the majority
of mussels aged between 3 and 6 years of age. The ages of mussels ascertained using the growth lines were not dissimilar to
the ages predicted from the length frequency distributions. Age at length curves produced using modal size class data were
not different from the data obtained using the pallial scar rings and internal growth lines. Taken together these data suggest
that M. barbatus attains a length of 40 and 50 mm within 5 and 8 years, respectively. Eighty one percent of individual M. barbatus injected with a Calcein seawater solution (300 mg Calcein l−1), into their mantle cavity successfully deposited a fluorescent line, which was visible in suitably prepared shell sections
under ultra violet light. Incorporation of Calcein into the mussel shells was seasonally variable with the lowest frequency
of incorporation in mussels marked in February and recovered in May. Seasonal shell growth was observed with significantly
higher growth rates in mussels marked in May and removed in August (ANCOVA, F
3,149 = 23.11, P < 0.001). Mussels (∼18 to 22 mm) marked in May and recovered in August displayed maximal growth rates of >2.5 mm month−1 compared with a mean mussel growth rate of 1.2 ± 0.6 mm month−1. At other times of the year mussel shell growth ranged from immeasurable to 1.48 mm month−1. 相似文献
189.
190.