全文获取类型
收费全文 | 201篇 |
免费 | 5篇 |
专业分类
林业 | 27篇 |
农学 | 3篇 |
基础科学 | 3篇 |
45篇 | |
综合类 | 13篇 |
农作物 | 8篇 |
水产渔业 | 11篇 |
畜牧兽医 | 85篇 |
园艺 | 6篇 |
植物保护 | 5篇 |
出版年
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 7篇 |
2013年 | 14篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有206条查询结果,搜索用时 187 毫秒
1.
K. Olsson 《EPPO Bulletin》1976,6(4):209-219
As it is difficult to detect ring rot in its latent form as well as in badly decayed tubers and in potato haulm, a diagnostic technique has been developed. With the help of a Turmix blender and a little water, a suspension is made of the suspected material. The suspension is inoculated into eggplants. Gram-staining of bacteria in sap from petioles of leaves showing symptoms is used to confirm the diagnosis. Some results obtained with this method applied on potatoes and potato haulm are described. 相似文献
2.
K. Olsson 《EPPO Bulletin》1976,6(4):199-207
Brown rot (Pseudomonas solanacearum [Smith] Smith) infection of 5% or less was found in potatoes from some fields in Southern Sweden at about 56° N in the years 1972 and 19732). The fields were irrigated with water from small streams. The pathogen has been isolated from a wild host, Solanum dulcamara, growing at the water's edge in one of the streams. The wild host is perennial and bacteria can overwinter in this host. Overwintering also occurred in artificially infected S. dulcamara at 59° N. No overwintering in soil has hitherto been demonstrated, in spite of experiments with artificially infested soil. Infections have probably originated from imported potatoes. 相似文献
3.
4.
Seasonal courses of light-saturated rate of net photosynthesis (A360) and stomatal conductance (gs) were examined in detached 1-year-old needles of Scots pine (Pinus sylvestris L.) from early April to mid-November. To evaluate the effects of soil frost and low soil temperatures on gas exchange, the extent and duration of soil frost, as well as the onset of soil warming, were manipulated in the field. During spring, early summer and autumn, the patterns of A360 and gs in needles from the control and warm-soil plots were generally strongly related to daily mean air temperatures and the frequency of severe frost. The warm-soil treatment had little effect on gas exchange, although mean soil temperature in the warm-soil plot was 3.8 degrees C higher than in the control plot during spring and summer, indicating that A360 and gs in needles from control trees were not limited by low soil temperature alone. In contrast, prolonged exposure to soil temperatures slightly above 0 degrees C severely restricted recovery of A360 and especially gs in needles from the cold-soil treatment during spring and early summer; however, full recovery of both A360 and gs occurred in late summer. We conclude that inhibition of A360 by low soil temperatures is related to both stomatal closure and effects on the biochemistry of photosynthesis, the relative importance of which appeared to vary during spring and early summer. During the autumn, soil temperatures as low as 8 degrees C did not affect either A360 or gs. 相似文献
5.
Bergquist SA Gertsson UE Nordmark LY Olsson ME 《Journal of agricultural and food chemistry》2007,55(21):8444-8451
Baby spinach ( Spinacia oleracea L.) was grown under three types of shade netting (high transmittance, spectrum-altering, and low transmittance) to study the effect on the concentrations of vitamin C (ascorbic acid and dehydroascorbic acid), carotenoids, and chlorophyll and on the visual quality of the leaves. The spinach was sown in April and August and harvested at two growth stages. After harvest, leaves were stored in polypropylene bags at 2 and 10 degrees C. Shading significantly decreased the ascorbic acid concentration of April-sown spinach by 12-33%, but in the August-sown spinach, the response was inconsistent. Concentrations of total carotenoids and total chlorophylls were significantly higher under the nettings in many cases, especially under the spectrum-altering and low-transmittance nettings. Postharvest visual quality and postharvest persistence of the compounds analyzed were not greatly affected by shading. We conclude that these shade nettings are acceptable to use in baby spinach production when it comes to the studied aspects of internal and external quality of the produce. 相似文献
6.
Anna Hellqvist Monika Schmitz Christina Lindberg Per-Erik Olsson Bertil Borg 《Fish physiology and biochemistry》2001,25(4):311-317
The mRNA expression of the LH- and FSH- subunits were measured in nesting and post-breeding male three-spined sticklebacks, Gasterosteus aculetaus, as well as in castrated and sham-operated nesting males. Furthermore, expression of an androgen induced kidney protein, spiggin, and 11-ketotestosterone (11KT) levels, were measured in the castrated and sham-operated males. Nesting males had significantly higher levels of both LH- and FSH- mRNA expression compared to post-breeding males. Furthermore, sham-operated males had significantly higher levels of LH- mRNA and spiggin mRNA expression than the castrated fish. Expression of FSH-, on the other hand, did not differ between castrated and sham-operated males. There were strong positive individual correlations between circulating levels of 11KT on the one hand and expressions of LH- and spiggin mRNA, whereas the correlation between 11KT levels and FSH- mRNA was weak. The negative effect of castration on -LH mRNA indicates that gonadal hormones stimulate this expression, whereas this was not the case for -FSH. The observed decline in -LH expression after the end of the breeding season may be the result of cessation of the gonadal stimulation of the pituitary. On the other hand, it is not likely that this can explain the decline in FSH- expression. 相似文献
7.
Heljä-Sisko Helmisaari Lilli Kaarakka Bengt A. Olsson 《Scandinavian Journal of Forest Research》2014,29(4):312-322
The review gives an overview of the increased utilization of forest biomass for energy. The emphasis is on Nordic countries, especially on Sweden and Finland with large biomass potentials and a high share of renewable energy in gross final energy consumption. The utilization and potential of forest chip sources such as logging residues, small-size tree stems and stumps that are normally not harvested in conventional harvesting are described. Environmental potential and impacts that may reduce the utilization of forest biomass are discussed based on recent publications. Finally, the review summarizes the future developments based on their relationship to policies, certifications and guidelines and forest owners' decisions. 相似文献
8.
Kjellenberg L Johansson E Gustavsson KE Olsson ME 《Journal of agricultural and food chemistry》2010,58(22):11703-11708
The amounts of three main polyacetylenes in carrots; falcarinol, falcarindiol, and falcarindiol-3-acetate, were determined by HPLC, during three seasons, in carrots harvested several times per season and at different locations in Sweden. The amounts of falcarindiol first decreased from a relatively high level and then increased later in the harvest season. The amounts of falcarindiol-3-acetate showed similar variations, whereas the amounts of falcarinol did not exhibit any significant variation during the harvest season. During storage the amount of polyacetylenes leveled off, increasing in samples initially low and decreasing in samples initially high in polyacetylenes. The amounts of all polyacetylenes varied significantly due to external factors and between stored and fresh samples. This variation opens up possibilities to achieve a chemical composition of polyacetylenes at harvest that minimizes the risk of bitter off-taste and maximizes the positive health effects reported in connection with polyacetylenes in carrots. 相似文献
9.
Sixty sows suffering from typical post-weaning TSS were divided into three groups: (1) 20 as negative controls (NC); (2) 20 as positive controls (PC) treated with vitamins, trace elements and antibiotics; and (3) 20 injected with amperozide (2 mg/kg body weight), a new neuroleptic compound with antistress and anxiolytic properties. Amperozide treated sows fully recovered (P less than 0.05) and 80% became pregnant, while figures for the PC and NC groups were only 15% and 10% respectively. Mortality was up to 50% in the NC, 40% in the PC and only 15% in the amperozide treated group (P less than 0.05). These field results warrant further studies in unravelling the aetiology and prevention of this condition. 相似文献
10.
Mairead Shore Phil Jordan Per-Erik Mellander Mary Kelly-Quinn Karen Daly James Tom Sims David P. Wall Alice Rowena Melland 《Journal of Soils and Sediments》2016,16(5):1643-1654