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71.
72.
Maria de Fátima Loureiro Glaciela Kaschuk Odair Alberton Mariangela Hungria 《Biology and Fertility of Soils》2007,43(6):665-674
In this study, soybean nodules were collected from 12 sites in the State of Mato Grosso, in the Brazilian Cerrados, where
both exotic soybean [Glycine max (L.) Merrill] and bradyrhizobial strains have been introduced from 1 to 18 years before. All soils were originally devoid
of rhizobia capable of effectively nodulating soybean and varied in terms of chemical and physical properties, inoculation
procedures, and cropping systems. Rhizobial genetic diversity was assessed on 240 isolates by rep-PCR fingerprinting with BOX primer, and indices of diversity (abundance-based coverage estimator and traditional and modified
Shannon indices) were applied to the profiles obtained. The genetic diversity was much greater than expected, as after the
introduction of a maximum of four strains, up to 13 profiles were identified, some sharing many similar bands with the inoculant
strains, but others quite distinct from the putative parental genotypes. The increase in the number of rep-PCR profiles could be attributed to genetic variability due to the stressful tropical environmental conditions, but also
might indicate that indigenous rhizobia become capable of nodulating the host legume. After the third year of cropping with
the host legume, inoculation did not affect rhizobial diversity. A high content of clay decreased diversity in comparison
with that seen in a sandy soil, probably due to reduced aeration. Diversity was higher under the no-tillage system when compared
to the conventional tillage management, highlighting the importance of maintaining crop residues in tropical soils. Understanding
the ecology of exotic rhizobia after being introduced into new cropping areas represents a first step towards the establishment
of better strategies of inoculation, which in turn may result in sustainability and higher plant yields. 相似文献
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Anelize Santi Milaré Flávia Augusta de Oliveira Stelio Pacca Loureiro Luna Márcia Valéria Rizzo Scognamillo Antonio de Queiroz-Neto 《Journal of Equine Veterinary Science》2013
Tramadol combines an μ opiate and nonopiate analgesic mechanism and might be a useful opioid in horses. This study evaluated the effect of IV tramadol on spontaneous locomotor activity (SLA), head height, and hoof withdrawal reflex (HWR) after thermal or electrical nociceptive stimuli in horses. Doses of 2 and 3 mg/kg tramadol did not affect HWR after electrical and thermal nociception, respectively. Head height and SLA were not modified by 2, 3, or 5 mg/kg tramadol. All horses treated with 5 mg/kg tramadol developed trembling in pectoral triceps, and gluteal muscles and adopted a base-wide stance. In conclusion, 2 and 3 mg/kg tramadol IV neither induced sedation nor prolonged HWR after thermal or electrical stimuli in conscious horses. The dose of 5 mg/kg tramadol IV produced excitement, and it is apparently unsuitable for clinical use. 相似文献
76.
Cytogenomic characterization of Colletotrichum kahawae,the causal agent of coffee berry disease,reveals diversity in minichromosome profiles and genome size expansion 下载免费PDF全文
A. S. Pires H. G. Azinheira A. Cabral S. Tavares D. Tavares M. Castro V. Várzea M. C. Silva R. Abranches J. Loureiro P. Talhinhas 《Plant pathology》2016,65(6):968-977
Colletotrichum kahawae is an emerging fungal pathogen, which has recently undergone a speciation process from a generalistic ‘C. gloeosporioides species complex' background by acquiring the unique capacity to infect green coffee berries, thus causing coffee berry disease. This is a severe and widespread disease in Africa and an imminent threat to Arabica coffee cultivation in Asia and America, if the pathogen enters those continents. Genetic diversity within C. kahawae is low but notorious differences in pathogen aggressiveness have been described. This work characterized two cytogenomic traits (genome size and minichromosome profiles) of a collection of C. kahawae isolates, representing the breadth of its genetic diversity and distinct aggressiveness classes, along with closely related taxa. The results obtained constitute the first flow cytometry‐based genome size estimation in the genus Colletotrichum and show a c. 8 Mb genome size expansion between C. kahawae (79·5 Mb on average) and its closest relatives (71·3 Mb), corroborating evidence indicating that C. kahawae (i.e. the coffee berry disease pathogens) should remain as a distinct species. Results have also shown the presence of two to five minichromosomes in C. kahawae, suggesting a positive relationship between the number of minichromosomes and the level of aggressiveness of the different isolates analysed, while no correlation could be established between aggressiveness and whole genome size. Overall, these results may be the basis for the identification of pathogenicity/aggressiveness‐related factors in such minichromosomes, and may provide clues to the characterization of specific markers for aggressiveness classes. 相似文献
77.
本研究推荐一种测定鱼饲料样品中钙、镁、锰、锌的方法,即采用超声波提取样品,然后用原子吸收光谱法(FAAS)进行后续的量化。提取液是0.10mol/L的HCl,建立的最佳萃取条件如下:100mg样品;样品粒度小于60μm;3个周期的超声时间为10s;超声功率为102W。这种方法运用于研究尼罗罗非鱼幼鱼日粮饲料样品中这些营养素的消化率。测得的结果与在金属养分提取过程中鱼饲料样品矿化结果一致。 相似文献
78.
OMNICROP uses a database composed of labeled data, such as light quality and quantity, general climate characteristics, and soil quality, from successful farming sites to sort and select the most successful crops for a particular set of circumstances. This process provides either earthbound farmers or off-world colonists with the a priori information needed to start successful, productive food production while preventing costly and time-consuming activities that derive from on-site experimentation. The model can also be directly linked to self-managing cultivation chambers, food seedling physiology assessment, and phytopathology treatment on Earth, and for deep space travel crop cultivation. Our results are derived from the comparison between five different algorithms, showing in this case the superiority of the algorithms based on ensemble of decision trees, especially the boosted trees, where our best estimator was the XGBoost. This project is an open source model where any user can input data and obtain results. Frequent reuse will assist the model with learning and continual self- recalibration, providing increasingly accurate results across time. 相似文献
79.
Effect of supplementation of dietary fibre concentrates on biochemical parameters,stress response,immune response and skin mucus of jundiá (Rhamdia quelen) 下载免费PDF全文
F.R. Goulart T.J. Adorian N.M. Lovatto B.B. Loureiro D. Pianesso L.G. Barcellos G. Koakoski L.P. da Silva 《Aquaculture Nutrition》2018,24(1):375-382
The aim of this study was to assess the effects of different dietary fibre concentrates (DFC: Mucilage = MG; pectin = PN or β‐glucan+mannan = βg+M), on biochemical parameters, stress and immune response and skin mucus of jundiá (Rhamdia quelen). The fish (7.16 ± 0.06 g) were fed with Control diet (0 g/kg of DFC); diet supplemented with 5 g/kg of commercial prebiotic (CP 5) or diets supplemented with 5 or 10 g/kg of MG; PN or βg+M. After 8 weeks of the feeding trials, biochemical parameters (cholesterol, glucose, albumin and total protein), cortisol, immunoglobulin IgM and mucoproteins of skin mucus were assessed. Results demonstrated that supplementation with PN increased cholesterol levels (p<.05). After application of the stressor, most fish, except those in the PN and 10 g/kg MG groups, showed significant increases (p<.05) in cholesterol, glucose and albumin levels. The jundiás showed no difference in cortisol levels after application of the stressor (p>.05). IgM levels were significantly high in fish supplemented with DFC (p<.05). However, the concentration of mucoproteins in skin mucus was not influenced in the different treatments (p>.05). The results showed that supplementation with DFC promoted beneficial effects on the metabolism of jundiá. 相似文献
80.
Survival to prescribed fire of plantation-grown Corsican black pine in northern Portugal 总被引:1,自引:0,他引:1