全文获取类型
收费全文 | 81篇 |
免费 | 3篇 |
专业分类
13篇 | |
综合类 | 11篇 |
水产渔业 | 3篇 |
畜牧兽医 | 55篇 |
植物保护 | 2篇 |
出版年
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2003年 | 2篇 |
2001年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1988年 | 1篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1970年 | 1篇 |
1969年 | 6篇 |
1968年 | 6篇 |
1967年 | 4篇 |
1966年 | 5篇 |
1965年 | 1篇 |
排序方式: 共有84条查询结果,搜索用时 22 毫秒
1.
2.
M. A. Orlova N. V. Lukina V. E. Smirnov N. A. Artemkina 《Eurasian Soil Science》2016,49(11):1276-1287
Presently, among the works considering the influence of forest trees on soil properties, the idea that spruce (Picea abies) promotes the acidification of soils predominates. The aim of this work is to assess the effects of spruce trees of different ages and Kraft classes on the acidity and content of available nutrient compounds in the soils under boreal dwarf shrub–green moss spruce forests by the example of forest soils in the Kola Peninsula. The soils are typical iron-illuvial podzols (Albic Rustic Podzols (Arenic)). Three probable ways of developing soils under spruce forests with the moss–dwarf shrub ground cover are considered. The soils under windfall–soil complexes of flat mesodepressions present the initial status. The acidity of organic soil horizons from the initial stage of mesodepression overgrowth to the formation of adult trees changed nonlinearly: the soil acidity reached its maximum under the 30–40-year-old trees and decreased under the trees older than 100 years. The contents of nitrogen and available nutrients increased. The acidity of the mineral soil horizons under the trees at the ages of 110–135 and 190–220 years was comparable, but higher than that under the 30–40-year-old trees. The differences in the strength and trends of the trees’ effect on the soils are explained by the age of spruce trees and their belonging to different Kraft classes. 相似文献
3.
Lukina N. V. Orlova M. A. Bakhmet O. N. Tikhonova E. V. Tebenkova D. N. Kasakova A. I. Kryshen A. M. Gornov A. V. Smirnov V. E. Shashkov M. P. Ershov V. V. Knyazeva S. V. 《Eurasian Soil Science》2019,52(7):793-807
Eurasian Soil Science - The effect of vegetation on soil properties (acidity, C/N ratio, content of exchangeable nutrients) was assessed for the northern and middle taiga forests in the Republic of... 相似文献
4.
M. A. Orlova N. V. Lukina V. E. Smirnov D. A. Krasnov I. O. Kamaev 《Eurasian Soil Science》2012,45(6):612-624
The development of fertility of soils on different parent rocks is considered for different types of spruce forests in the Khibiny Mountains. The spruce forests of Mts. Kuel??por, Vud??yavrchorr, Chil??mana, and Saami were the objects for the study. The results showed that the fertility level of the soils of the Khibiny Mountains was determined by the combined influence of the parent rock??s composition and the vegetation. The differences in the soil properties are mainly explained by the composition of the parent rocks. The pod-burs differ from the podzols by the higher contents of organic matter, nitrogen, and available nutrients. The podzols are the most acid soils there. The podburs of Mt Kuel??por developing on base-rich parent rocks are the most fertile. The differences in the fertility of the soils on the intrabiogeocenotic (tessera) level are related to the vegetation. The soils of the spruce and tall-grass tesseras are richer in nitrogen, calcium, and manganese as compared to the soils of the dwarf shrub-green moss, low-grass-dwarf shrub-green moss, and tussock grass-dwarf shrub tesseras. 相似文献
5.
N. V. Gopp T. V. Nechaeva O. A. Savenkov N. V. Smirnova V. V. Smirnov 《Eurasian Soil Science》2017,50(11):1332-1343
The informativeness of NDVI for predictive mapping of the physical and chemical properties of plow horizons of soils on different slope positions within the first (280–310 m a.s.l.) and second (240–280 m a.s.l.) altitudinal steps has been examined. This index is uninformative for mapping soil properties in small hollows, whose factual width is less than the Landsat image resolution (30 m). In regression models, NDVI index explains 52% of variance in the content of humus; 35 and 24% of variance in the contents of total and nitrate nitrogen; 19 and 29% of variance in the contents of total and available phosphorus; 25 and 50% of variance in the contents of exchangeable calcium and manganese; and 30 and 29% of variance in the contents of fine silt and soil water, respectively. On the basis of the models obtained, prognostic maps of the soil properties have been developed. Spatial distribution patterns of NDVI calculated from Landsat 8 images (30-m resolution) serve as the cartographic base and the main indicator of the soil properties. The NDVI values and the contents of humus, physical clay (<0.01 mm) and fine silt particles, total and nitrate nitrogen, total phosphorus, and exchangeable calcium and manganese in the soils of the first altitudinal step are higher than those in the soils of the second altitudinal step. An opposite tendency has been found for the available phosphorus content: in the soils of the second altitudinal step and the hollow, its content is higher than that in the soils of the first altitudinal step by 1.8 and 2.4 times, respectively. Differences in the pH of soil water suspensions, easily available phosphorus, and clay in the soils of the compared topographic positions (first and second altitudinal steps and the hollow) are statistically unreliable. 相似文献
6.
Anatoli Savchenko Vladimir Smirnov Pavel Svirkunov 《Water, air, and soil pollution》1979,12(4):407-415
A mechanism is proposed for low-temperature transfer of impurity ions from electrolyte solutions into air taking into account the physico-chemical structure of the liquid and its surface, as well as meteorological factors. The model adequately describes the experimental data obtained by the present authors, and Azad and Latham (1967). The recommendations on concentration limits for some industrial impurities in sewage are given. 相似文献
7.
8.
9.
10.