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61.
Zenith Gaye Almeda Orozco Joemel Gentelizo Sumbing Ma. Junemie Hazel Lebata‐Ramos Satoshi Watanabe 《Aquaculture Research》2014,45(7):1153-1163
The ability of Holothuria scabra to digest nutrients, such as organic matter (OM), protein and carbohydrate from animal and plant feed ingredients was investigated. Four test feeds prepared by mixing sand with single ingredients from animal sources (shrimp and mussel) and plant sources (diatom and seaweed) were fed to H. scabra to estimate apparent digestibility coefficient (ADC). The total assimilated nutrient (TAN) increased with ADC, whereas ingestion rate (IR) varied slightly among the feeds suggesting that ADC might be a good indicator of nutrient availability to H. scabra. The ADCOM of shrimp and mussel was significantly higher than that diatom and seaweed: 86.2%, 77.1%, 55.1% and 32.3% respectively. ADCprotein was similar for shrimp (88.7%), mussel (84.8%) and diatom (75.2%), but significantly lower in seaweed (34.4%). ADCcarbohydrate was similar in mussel (58.5%) and diatom (58.3%) as well as in seaweed (31.6) and shrimp (28.0%). ADCprotein was relatively higher than ADCcarbohydrate suggesting that H. scabra generally digests more protein than carbohydrate. Furthermore, results indicated that nutrients from animal‐based feeds are more efficiently digested by H. scabra; thus, animal ingredients rich in easily digestible protein could potentially provide an efficiently balanced diet for H. scabra fed with diatom containing high easily digestible carbohydrate. 相似文献
62.
Fiona R. Hay Flora de Guzman David Ellis Hazel Makahiya Teresita Borromeo N. Ruaraidh Sackville Hamilton 《Genetic Resources and Crop Evolution》2013,60(1):275-296
Germination ability, equilibrium relative humidity (eRH), and moisture content of ‘control’ seed samples representing 183 rice accessions stored in the active (2–4 °C) and base (?10 °C until 1993, then ?20 °C) collections of the T. T. Chang Genetic Resources Center were determined after storage for 20.5–30.5 years. Germination of seeds that had been stored in the base collection was generally high (>70 %), whereas germination was more variable for seeds stored in the active collection. Samples with lower viability after storage in the active collection were likely to have lower viability after storage in the base collection. There were significant differences in the moisture content-eRH relationship of the seeds depending on whether the seeds had been stored in the active or base collection. Based on re-test data for regular seed samples regenerated in 1979–1980 and stored in the active collection for up to 31 years, estimates of the time for ability to germinate to fall to 50 % (p 50) ranged from 54 to 997 years. For the same seed samples stored in the base collection for approximately 31 years, ability to germinate has been maintained and germination increased due to improved procedures. The ability to germinate of base collection samples was also generally higher than that of ‘safety duplicate’ samples of the same seed lots that had been sent to the National Center for Genetic Resources Preservation, USA in 1981 and stored at ?18 °C. This may have been due to uptake of moisture either during processing for dispatch or as a consequence of poor packaging material. The results are discussed in relation to long-term seed storage and genebank management. 相似文献
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The utility of simple fish community metrics for evaluating the relative influence of fishing vs. other environmental drivers on Caribbean reef fish communities 下载免费PDF全文
Fish community metrics have been extensively investigated as indicators of fishing effects for ecosystem‐based fisheries management (EBFM) in temperate systems. Little similar work has been performed in the coral reefs of the Caribbean, where simple indicators are urgently needed. Here, we use 415 coral reef surveys throughout the Caribbean to assess the potential of four simple and intuitive fish community metrics, namely, fish biomass, fish density, average fish weight and species richness, to separate fishing effects from those of other environmental factors at both local (tens of kilometres) and broad (hundreds to thousands of kilometres) spatial scales. We found that these fish metrics differed considerably in environmental correlates and the spatial scales underlying fish metric–environment associations. Average fish weight and fish biomass were most sensitive to fishing indices at both spatial scales, although average fish weight responded more sensitively and specifically to fishing than fish biomass. Fish density and species richness were most sensitive to temperature over broad scales and to macroalgae and relief height over local ones. All fish metrics were negatively correlated with macroalgae over broad scales, supporting the utility of macroalgae to inform about the integrity of entire reef ecosystems. Most of the fish metric variance associated with fishing pressure operated over broad scales, highlighting the need for a Caribbean‐wide view of fish community status to establish local management objectives and avoid shifting baselines. Our study clarifies the utility of simple fish community metrics as indicators of fishing effects for EBFM in the Caribbean. 相似文献
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The topography of a surface is known to substantially affect the bulk properties of a material. Despite the often nanoscale nature of the surface undulations, the influence they have may be observed by macroscopic measurements. This review explores many of the areas in which the effect of topography is macroscopically relevant, as well as introducing some recent developments in topographic analysis and control. 相似文献
68.
The emergence of a new strain of porcine circovirus-2 in Ontario and Quebec swine and its association with severe porcine circovirus associated disease — 2004–2006 下载免费PDF全文
Susy Carman Hugh Y. Cai Josepha DeLay Sameh A.Youssef Beverly J. McEwen Carl A. Gagnon Donald Tremblay Murray Hazlett Peter Lusis Jim Fairles Hazel S. Alexander Tony van Dreumel 《Canadian journal of veterinary research》2008,72(3):259-268
In the late fall of 2004 more severe lesions of porcine circovirus-2 associated disease (PCVAD) than usual occurred during an outbreak of porcine circovirus-2 (PCV-2) infection in Ontario nursery and grower/finisher pigs. The lesions were of unprecedented severity and included diffuse bronchointerstitial pneumonia, granulomatous enteritis, vasculitis, interstitial nephritis, and new lesions of splenic infarction. Some affected herds had up to 50% mortality. The outbreak correlated with the sudden emergence of a variant PCV-2, with PCR restriction fragment length polymorphism (RFLP) type 321. Phylogenetic comparison of ORF2 sequences and full genome sequences showed the new variant to be different from the previously dominant RFLP type 422 viruses, and similar to viruses that had occurred in France and other European and Asian countries. A subsequent retrospective study showed a statistically significant increase in the frequency of histological lesions in lymph node, spleen, lung, small intestine, colon and kidney, for pigs spontaneously infected with RFLP type 321, compared with the older RFLP type 422 strain. Viral burden, based on IHC staining in lymph node, also showed a statistically significant increase in pigs infected with the newer variant RFLP type 321, compared with the older RFLP type 422 strain. This enhanced virulence in pigs infected with PCV-2 RFLP type 321 strain may be related to the genetic differences in this new strain of PCV-2. This virus is now the dominant strain of PCV-2 virus found in Ontario and Quebec swine. 相似文献