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41.
J.E. Olesen M. Trnka K.C. Kersebaum A.O. Skjelvåg B. Seguin P. Peltonen-Sainio F. Rossi J. Kozyra F. Micale 《European Journal of Agronomy》2011,34(2):96-112
The studies on anthropogenic climate change performed in the last decade over Europe show consistent projections of increases in temperature and different patterns of precipitation with widespread increases in northern Europe and decreases over parts of southern and eastern Europe. In many countries and in recent years there is a tendency towards cereal grain yield stagnation and increased yield variability. Some of these trends may have been influenced by the recent climatic changes over Europe.A set of qualitative and quantitative questionnaires on perceived risks and foreseen impacts of climate and climate change on agriculture in Europe was distributed to agro-climatic and agronomy experts in 26 countries. Europe was divided into 13 Environmental Zones (EZ). In total, we had 50 individual responses for specific EZ. The questionnaires provided both country and EZ specific information on the: (1) main vulnerabilities of crops and cropping systems under present climate; (2) estimates of climate change impacts on the production of nine selected crops; (3) possible adaptation options as well as (4) adaptation observed so far. In addition we focused on the overall awareness and presence of warning and decision support systems with relevance for adaptation to climate change.The results show that farmers across Europe are currently adapting to climate change, in particular in terms of changing timing of cultivation and selecting other crop species and cultivars. The responses in the questionnaires show a surprisingly high proportion of negative expectations concerning the impacts of climate change on crops and crop production throughout Europe, even in the cool temperate northern European countries.The expected impacts, both positive and negative, are just as large in northern Europe as in the Mediterranean countries, and this is largely linked with the possibilities for effective adaptation to maintain current yields. The most negative effects were found for the continental climate in the Pannonian zone, which includes Hungary, Serbia, Bulgaria and Romania. This region will suffer from increased incidents of heat waves and droughts without possibilities for effectively shifting crop cultivation to other parts of the years. A wide range of adaptation options exists in most European regions to mitigate many of the negative impacts of climate change on crop production in Europe. However, considering all effects of climate change and possibilties for adaptation, impacts are still mostly negative in wide regions across Europe. 相似文献
42.
Nagy A Machova J Hornickova J Tomci M Nagl I Horyna B Holko I 《Veterinary microbiology》2007,120(1-2):9-16
In order to determine the actual prevalence of avian influenza viruses (AIV) in wild birds in the Czech Republic extensive surveillance was carried out between January and April 2006. A total of 2101 samples representing 61 bird species were examined for the presence of influenza A by using PCR, sequencing and cultivation on chicken embryos. AIV subtype H5N1 was detected in 12 Mute swans (Cygnus olor). The viruses were determined as HPAI (highly pathogenic avian influenza) and the hemagglutinin sequence was closely similar to A/mallard/Italy/835/06 and A/turkey/Turkey/1194/05. Following the first H5N1 case, about 300 wild birds representing 33 species were collected from the outbreak region and tested for the presence of AIV without any positive result. This is the first report of highly pathogenic avian influenza subtype H5N1 in the Czech Republic. The potential role of swan as an effective vector of avian influenza virus is also discussed. 相似文献
43.
A simple statistical model for predicting herbage production from permanent grassland 总被引:1,自引:0,他引:1
M. Trnka J. Eitzinger† G. Gruszczynski† K. Buchgraber‡ R. Resch‡ A. Schaumberger‡ 《Grass and Forage Science》2006,61(3):253-271
The considerable year‐to‐year and seasonal variation in grassland production is of major importance to dairy farmers in Europe, as production systems must allow for the risk of unfavourable weather conditions. A large portion of the variability is caused by weather and its interaction with soil conditions and grassland management. The present study takes advantage of the interactions between weather, soil conditions and grassland management to derive a reliable grassland statistical model (GRAM) for grasslands under various management regimes using polynomial regressions (GRAM‐R) and neural networks (GRAM‐N). The model performance was tested with a focus on predicting its capability during unusually dry or wet years using long‐term experimental data from Austrian sites. The GRAM model was then coupled with the Met&Roll stochastic weather generator to provide estimates of harvestable herbage dry matter (DM) production early in the season. It was found that, with the GRAM‐N or GRAM‐R methodology, up to 0·78 of the variability in harvested herbage DM production could be explained with a systematic bias of 1·1–2·3%. The models showed stable performance over subsets of dry and wet years. Generalized GRAM models were also successfully used to estimate daily herbage growth during the season, explaining between 0·63 and 0·91 of variability in individual cases. It was possible to issue a probabilistic forecast of the harvestable herbage DM production early in the season with reasonable accuracy. The overall results showed that the GRAM model could be used instead of (or in parallel with) more sophisticated grassland models in areas or sites where complete data sets are not yet available. As the model was tested under various climatic and soil conditions, it is suggested that the proposed approach could be used for comparable temperate grassland sites throughout Europe. 相似文献
44.
Giorgio Vacchiano R. Justin Derose John D. Shaw Miroslav Svoboda Renzo Motta 《European Journal of Forest Research》2013,132(3):535-549
Norway spruce is one of the most important conifer tree species in Europe, paramount for timber provision, habitat, recreation, and protection of mountain roads and settlements from natural hazards. Although natural Norway spruce forests exhibit diverse structures, even-aged stands can arise after disturbance or as the result of common silvicultural practice, including off-site afforestation. Many even-aged Norway spruce forests face issues such as senescence, insufficient regeneration, mechanical stability, sensitivity to biotic disturbances, and restoration. We propose the use of Density Management Diagrams (DMD), stand-scale graphical models designed to project growth and yield of even-aged forests, as a heuristic tool for assessing the structure and development of even-aged Norway spruce stands. DMDs are predicated on basic tree allometry and the assumption that self-thinning occurs predictably in forest stands. We designed a DMD for Norway spruce in temperate Europe based on wide-ranging forest inventory data. Quantitative relationships between tree- and stand-level variables that describe resistance to selected natural disturbances were superimposed on the DMD. These susceptibility zones were used to demonstrate assessment and possible management actions related to, for example, windfirmness and effectiveness of the protective function against rockfall or avalanches. The Norway spruce DMD provides forest managers and silviculturists a simple, easy-to-use, tool for evaluating stand dynamics and scheduling needed density management actions. 相似文献
45.
Libor Mrnka Michal Kuchár Zuzana Cieslarová Pavel Matějka Jiřina Száková Pavel Tlustoš Miroslav Vosátka 《Water, air, and soil pollution》2012,223(1):399-410
There is increasing interest in poplars and willows due to their biomass production and phytoremediation potential. They host
two major types of mycorrhizal fungi that can substantially modulate the physiology of their hosts. In this study, the effects
of endo- and ectomycorrhizal fungi on growth, physiological parameters, and heavy metals accumulation were studied in a pot
experiment using Salix alba L. and Populus nigra L. The mycorrhizal fungi were inoculated separately and in combination to a soil substrate polluted by a mixture of heavy
metals (mainly Cd, Pb, and Zn). Tree species differed in their mycorrhizal affinities, with poplar being colonized predominantly
by Glomus intraradices and willow by Hebeloma mesophaeum. H. mesophaeum increased willow height and biomass, while G. intraradices decreased poplar height. The photosynthetic rate remained unchanged, and only minor changes were observed in the relative
composition of photosynthetic pigments. Poplar photosynthetic rates and levels of photosynthetic pigments declined, while
the epicuticular waxes in leaves increased toward the end of the experiment, irrespective of the inoculation. H. mesophaeum strongly reduced the accumulation of Cd and Fe in willow and poplar shoots, respectively. Our results support the use of
selected mycorrhizal strains to tune phytoremediation outcomes in their plant hosts. 相似文献
46.
Ludmila Machů Dušan Samek Jan Hrabě Miroslav Fišera 《Journal Of Aquatic Food Product Technology》2013,22(5):423-435
Digestibility is an important factor in determining the level of nutritive factors utilization. Determination of in vitro digestibility in a Daisy incubator and assessment of protein digestibility using Kjeldahl method of algal food products after pepsin, pancreatin, and combined hydrolysis of both enzymes was described. The influence of different hydrolysis times on algal digestibility was investigated in brown seaweeds, red seaweeds, and green alga. The highest digestibility values were generally determined in red seaweeds after 24 h of combined hydrolysis by pepsin and pancreatin. Direct dependence between digestion time and digestion efficiency was verified and statistically proven. 相似文献
47.
We compared two different strategies to increase the catches of Ips typographus (L.), particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating
pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands.
The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended
to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier
traps targeting primarily males, with a lower percentage of (4S)-cis-verbenol (cV), the (−)-α-pinene was replaced step wise with (+)-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This
replacement had no significant effect on the numbers of responding I. typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting
females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol (MB) was replaced with 1-methoxy-2-propanol (MP) in a similar
fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is possible
to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps,
the (−)-α- pinene was replaced with (+)-limonene and MB with MP. The replacement of (−)-α-pinene had only a slight effect
on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping
efficacy.
Foundation project: The research was supported by Slovak Research and Development Agency (APVV-51-P06005 and APVV-27-P05205)
and by the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences
(2/6153/26) 相似文献
48.
This study examines the structural characteristics of the tree layer, dead wood, canopy openings, and regeneration patterns of a spruce old-growth forest in the Bohemian Forest, Czech Republic. An old-growth stand with minor human influence and a stand that was presumably logged about 200 years ago were analyzed and compared, as some forest managers considered the presumable human impact as a reason for salvage logging. Even though the stands differed in tree density, height and DBH structure, it was not possible to conclude whether it was due to management history or the environmental differences. The volume of dead wood also differed between the stands. There was about 142 and 83 m3 ha−1 of dead wood in the old-growth stand and presumably logged stand, respectively. The amount of dead wood found in the old-growth stand was comparable with values reported from spruce old-growth stands across Central Europe. In both stands, many canopy trees were arranged in linear patterns, which was a result of spruce regeneration on nurse logs. This suggests that the origin and development of the stands were characterized by natural processes and during the past 200 years typical old-growth structural characteristics have already evolved. 相似文献
49.
Lukáš Predajňa Nina Sihelská Daniela Benediková Katarína Šoltys Thierry Candresse Miroslav Glasa 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(4):877-885
Although Prune dwarf virus (PDV) is one of the most common viruses infecting stone fruits (Prunus spp.), most of the molecular diversity studies have so far focused on the capsid protein (CP) gene. An alternative diagnostic primer pair targeting the movement protein (MP) gene was used in the present work, increasing then polyvalence of PDV detection in cherry samples from Slovakia as compared to the previously published primers amplifying 5′MP-intergenic region-CP-3′UTR fragment. The nearly complete sequence of the RNA3 from 24 Slovak PDV isolates was determined, together with 19 partial sequences of the MP gene for other isolates. Even though the isolates originated from a geographically limited region, analyses showed a high degree of nucleotide sequence diversity between isolates. No clear-cut phylogenetic grouping based on host or geographical origin could be observed. The topology of the MP and CP trees were incongruent for some isolates. Highly supported recombination signals were detected in five PDV isolates, with breakpoints located at different positions in the central part of RNA3, within or close to the intergenic region. Taken together these results extend our understanding of the variability of PDV and for the first time highlight the contribution of recombination to the evolutionary history of this virus. 相似文献
50.
Nora Polláková Vladimír Šimanský Miroslav Kravka 《Journal of Soils and Sediments》2018,18(8):2790-2800