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381.
In situ coagulation and transection of the ovarian pedicle: An alternative to laparoscopic ovariectomy in juvenile horses 总被引:1,自引:0,他引:1
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Ryan W. Shoemaker Emma K. Read Tanya Duke David G. Wilson 《Canadian journal of veterinary research》2004,68(1):27-32
The feasibility of leaving the ovaries within the peritoneal cavity after laparoscopic coagulation and transection of the ovarian pedicle was assessed in the juvenile horse. Elective ovariectomy was performed on 10 quarter horses, aged 4 to 5 mo, with the fillies in a Trendelenburg position. The mesovarium was isolated, and multiple coagulation and transection cycles were performed until all ovarian attachments had been severed. The ovaries were dropped within the abdomen, and hemostasis of the transected mesovarium was evaluated before closure. The mean surgical time was 33 min (range, 23 to 48 min). Ten weeks after surgery the fillies were humanely euthanized. At postmortem examination, the ovary location within the abdomen was noted. In 1 horse, there was an abdominal adhesion; viscera had been punctured during insufflation. Of the 20 ovaries, 4 were free-floating within the abdominal cavity; the other 16 were enveloped in the free portion of the greater omentum in the cranioventral abdomen. Histologic examination of the ovaries was performed to assess follicle cell viability. In both the free-floating and the attached ovaries, the deep blood vessels and all examined follicular structures were necrotic and partially mineralized. Laparoscopic electrosurgical transection of the ovarian pedicle without removal of the ovaries should be considered an alternative to other ovariectomy techniques that may be performed in young female horses. 相似文献
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Paul Eggleton Kelly Inward Joanne Smith David T. Jones Emma Sherlock 《Soil biology & biochemistry》2009,41(9):1857-1865
There are very few studies on the effects of temporal changes in soil properties on ecosystem engineers in UK soils. This study addresses this lack by presenting earthworm diversity data from a six-year seasonality study comprising 72 monthly samples from the litter and soil of pasture woodland in the New Forest, southern England. These data were analysed in the context of soil moisture and soil temperature, key factors affecting earthworm abundance, and factors likely to be strongly affected by future climate change. The data for the whole period were analysed using non-parametric regression and an additive model used to separate within-year and between-year effects. Seasonal patterns are present for all the common species, generally with a maximum in March and a minimum in September. A majority of the five commonest species show a strong decline in abundance during the two extremely dry periods (2002–2003 and 2006). In sharp contrast, the same species showed a relative increase during the very wet summer and autumn of 2007. There was, however, no significant overall trend in either the climate data or the earthworm species data. The epigeic species, Dendrobaena octaedra, showed the largest decline in the driest months which caused a crash to the point where there were no adults sampled during the four dry summer months of 2003. A second congeneric species, Dendrobaena attemsi, also epigeic, appears to have invaded the woodland during the six year period and is increasing rapidly in abundance. This may indicate the start of a shift in the distribution of the two species, as D. octaedra generally has a northern European distribution and is frost-tolerant, while D. attemsi has a southern European distribution and is more drought-tolerant. In contrast, the very wet summer of 2007 seems to have damped the usual periodic seasonal oscillations in earthworm numbers. Endogeic worm species do not show the D. octaedra seasonal pattern as obviously, probably because these species are able to move more freely through the soil and because they are able to aestivate. These changes are likely to be due to a combination of human movement of earthworms (e.g. D. attemsi) and variations in local climate. 相似文献
385.
Steve C. Sheppard Doug J. Cattani Kim H. Ominski Bill Biligetu Shabtai Bittman Emma J. McGeough 《Grass and Forage Science》2019,74(1):6-18
Sainfoin (Onobrychis viciifolia) is a forage legume of renewed interest in western Canada, with equally weighted advantages and disadvantages. In agronomic attributes, sainfoin is, at best, equal in yield, crude protein content and persistence to alfalfa (Medicago sativa). Sainfoin is equally or more palatable than alfalfa to ruminants, with comparable levels of animal productivity per unit forage consumed. The advantages it has compared to alfalfa include the following: (a) mitigation of frothy bloat; (b) reduced ammonia emissions (more faecal nitrogen (N) and less urinary N); (c) equal or better N retention by ruminants; and (d) anthelmintic protection from intestinal parasites. These advantages may be attributed to the presence of condensed tannins (CT), in legumes such as sainfoin. Emphasis on agronomic characteristics in breeding programmes appears to have led to the inadvertent reduction in the efficacy of CT characteristics. Persistence of sainfoin appears to be dependent on minimal pressure from competing plants, harvest or grazing, and good growth conditions from mid‐summer into fall, allowing for adequate root reserves for survival. It is possible that judicious use of glyphosate in late season might lessen competition in that critical period as sainfoin is more glyphosate‐tolerant than alfalfa. Otherwise, sainfoin may be best considered a short‐lived forage and best adapted for early season harvest or grazing to eliminate the risk of bloat. 相似文献
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We investigated the potential of Fraxinus americana L. to adapt to climate change by comparing diameter growth, survival and physiological status of 44 populations of 30-year-old trees originating from throughout the species range and grown in a common garden. Populations originating closest to the latitude of the common garden had the most rapid diameter growth and the highest survival. Among populations originating within a narrow latitudinal band along an east-west gradient of decreasing precipitation, those from the drier western end were best adapted to the dry climate of the common garden site, as judged by survival, stem circumference, leaf and wood carbon isotope ratios, leaf mass per area and leaf nitrogen concentration. These findings suggest that eastern populations may not perform well under the hotter and drier conditions predicted by climate change scenarios. Moreover, in the event of significant climate change, the short-term acclimation responses (within a generation) of F. americana may be insufficient to ensure the continued vigor or survival of this species throughout much of its present range. 相似文献
388.
An ethyl acetate extract of bark from Evodia elleryana produced significant growth inhibition of Mycobacterium tuberculosis at concentrations only minimally inhibitory to human T cells. The crude extract yielded 95% inhibition of TB at 50 microg/ml. The crude extract yielded 29% growth inhibition of human T-cells in culture at that concentration. 相似文献
389.
Thomas Stamp Elizabeth West Steve Colclough Shaun Plenty Benjamin Ciotti Tim Robbins Emma Sheehan 《Fisheries Management and Ecology》2023,30(1):44-55
Saltmarsh provides essential fish feeding and nursery habitat but has globally declined by 50%. We used a statistical block design to compare fish feeding activity within human-engineered or “re-aligned” saltmarsh to established saltmarsh. Linear and multivariate modelling highlighted that Thinlip Mullet (Chelon ramada) and European Bass (Dicentrarchus labrax) feeding rates were 16% and 31% lower within re-aligned than established saltmarshes, whereas Gobies (Pomatoschistus spp.) fed at the same rate as in both habitats. Analysis of European bass and Goby gut contents highlighted that important detritivorous prey species were up to 85.6% lower in re-aligned sites. Lower vegetation density may have negatively affected the feeding ecologies of fishes within re-aligned sites. However, due to the ecological value and potential for further improvement or habitat development, continued assessment of the beneficial effects of re-aligned sites for fisheries and net gain perspectives is needed. 相似文献
390.
Jordan P Cuff Fredric M Windsor Emma C Gilmartin Lynne Boddy T Hefin Jones 《Journal of insect science (Online)》2021,21(5)
Hollows of veteran trees (i.e., rot holes) provide habitat for many rare and threatened saproxylic invertebrates. Rot holes are highly heterogeneous, particularly in terms of substrate and microclimate conditions. There is, however, a dearth of information regarding the differences in biological communities inhabiting rot holes with different environmental conditions. Invertebrates were sampled from European beech (Fagus sylvatica) rot holes in Windsor, Savernake, and Epping Forests (United Kingdom). For each rot hole, physical and environmental conditions were measured, including tree diameter, rot hole dimensions, rot hole height, substrate density, water content, and water potential. These parameters were used to assess the influence of environmental conditions and habitat characteristics on invertebrate communities. Rot hole invertebrate communities were extremely diverse, containing both woodland generalist and saproxylic specialist taxa. Large variation in community structure was observed between rot holes and across woodlands; all sites supported threatened and endangered taxa. Environmental conditions in rot holes were highly variable within and between woodland sites, and communities were predominantly structured by these environmental conditions. In particular, turnover between invertebrate communities was linked to high β-diversity. The linked heterogeneity of environmental conditions and invertebrate communities in rot holes suggests that management of deadwood habitats in woodlands should strive to generate environmental heterogeneity to promote invertebrate diversity. Additional research is required to define how management and conservation activities can further promote enhanced biodiversity across rot holes. 相似文献