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91.
Turnover of nitrogen-rich root nodules follows the pruning of legume trees, forming a potentially important yet little studied
way of N release to the soil. The effects of soil moisture, herbivory by soil mesofauna and microbial decomposition on the
disappearance rate of woody legume nodules was studied in two tree/grass forage production associations. Litter bags containing
nodules of Erythrina variegata L. (Papilionoideae: Phaseoleae) were incubated for four weeks in grass-covered alleys between Gliricidia sepium (Jacq.) Walp. (Papilionoideae: Robinieae) hedgerows, established on a deep alluvial Oxisol under a humid tropical climate
and on a shallow Vertisol under a subhumid tropical climate in Guadeloupe, French Antilles. Soil moisture was regulated by
irrigating or covering small plots from natural rainfall. Fine nylon mesh bags were used to study the rate of microbial decomposition,
and open-ended perforated cylinders were used to estimate nodule herbivory. The chemical traits, especially the lignin: nitrogen
ratio, of E. variegata and G. sepium nodules were similar (lignin: N 1.70 and 1.55, respectively), and suggest that the results are probably also applicable to
the G. sepium nodules in the associations. Both soil moisture and decomposing agent (microbes or mesofauna) had a significant effect on
the nodule disappearance rate, but soil type did not have any apparent effect. The nodule half-life varied from three to seven
days under different treatments. The N release rate from the nodules was high, with N half-life varying from three to five
days. Herbivory accounted for ca. 10% of total mass and N loss from nodules during the four-week field incubation period,
but its importance increased towards the end of the incubation, especially in Vertisol, after the most easily decomposable
part of the nodules had decayed. After pruning, the nodule N is released to soil more rapidly than from mulch.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
92.
93.
Season appears to influence the physiology of bottlenose dolphins (Tursiops truncatus). From 2000 to 2005, blood parameters of three captive bottlenose dolphins housed in northern Italy were examined to determine if seasonal variation was present. Seasonal variation was observed in the male dolphins, with both males exhibiting aminotransferase levels that were higher in autumn and lower in winter. Mean serum creatinine levels were higher during summer and lower during autumn in the adult male, and mean lactate dehydrogenase higher during summer and lower during spring in the juvenile male. Both males exhibited red blood cell counts and hemoglobin levels that were higher during autumn and lower during summer. This study contributes to the knowledge of baseline hematologic and biochemical values based on seasonality in bottlenose dolphins. 相似文献
94.
Barbarita Companioni Mayda Arzola Yania Rodríguez Marais Mosqueda María Cristina Pérez Orlando Borrás José Carlos Lorenzo Ramón Santos 《Euphytica》2003,130(3):341-347
Banana and plantain are among the most important food crops in developing countries but production is threatened by increasing
virulent forms of Fusarium oxysporum f. sp. cubense. Chemical control is not economically effective and,therefore, breeding programs are necessary. Traditional field studies
of new genotype resistance to this disease are time-consuming and destructive. Therefore,we developed a rapid and non-destructive
procedure to differentiate field-grown banana resistant from susceptible clones. This procedure implicates application of
culture filtrates of Fusarium oxysporum f. sp. cubense race 1 onto banana leaves. The relationship between duration of the fungal in vitro incubation, and the fungal culture fresh mass, the culture filtrate absorbency, and the Gross Michel (susceptible cultivar)leaf
lesion area (after application of the culture filtrate) were similar and at 24day-incubation the highest values of the recorded
indicators were observed. A comparison between Gross Michel and FHIA-01(resistant) was also performed. The most relevant differences
between cultivars were observed at 48 hours after application of the culture filtrate, and in the middle-aged leaves. The
position of the culture filtrate application in the leaf limb (distal, middle, proximal) was not determinant. A wider comparison
among banana cultivars confirmed previous results informed by other researchers using different systems to study this plant-fungus
interaction. Such a confirmation validates the effectiveness of the procedure described here to select rapid and non-destructively
banana resistance to this disease at field level.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
95.
Chong Chen Songsong Chen Rohit Kumar Jha Lorenzo Cotrozzi Cristina Nali Giacomo Lorenzini Limin Ma 《Journal of Agronomy and Crop Science》2020,206(3):338-351
To compare the phenolic responses under oxidative stressors, plants of two Italian cultivars of durum wheat (Claudio and Mongibello) were (a) exposed to ozone (O3) (80 ppb, 5 hr/day for 70 consecutive days), with the aim to investigate the changes of phenolic compound contents in their leaves, or (b) flooded (seven consecutive days). Plants showed O3-induced visible injury, but their photosynthetic performance was not affected by the pollutant. Specifically, Claudio showed a higher O3 tolerance than Mongibello. The major value of the present study is undoubtedly the pioneering investigation of phenolic metabolism of durum wheat under O3. We identified 12 foliar phenolic compounds in all leaf samples (i.e. controls, exposed to O3 and flooded): ten phenolic acids, a flavanol (catechin hydrate) and a phenolic aldehyde (syringaldehyde). Overall, O3 exposure resulted in accumulations of phenolic compounds, especially in Claudio. These responses can be likely considered a fine-regulated repair process that equipped Claudio stressed plants with an antioxidant system capable of scavenging oxidative stress. Different phenolic variations were found in flooded plants, suggesting that phenolic response to environmental constraints is stress specific. Our study confirms that investigations and characterization of specific phenolic profiles of crop cultivars under oxidative stress may be helpful in breeding programmes. 相似文献
96.
Lorenzo Crosta Helga Gerlach Marcellus Bürkle Linda Timossi 《Veterinary Clinics of North America: Exotic Animal Practice》2003,6(1):57-83
Disorders of the reproductive system represent a large portion of both large and small domestic animal medicine. Although some disorders of this system have been extensively studied in birds, this science is still in its infancy, when compared to mammalian reproductive medicine. This may be due to several reasons, but the simple fact that birds are oviparous renders knowledge of mammalian reproductive anatomy, histology, physiology, and disease process, inapplicable to avian patients. Nevertheless, several specific diseases or conditions affecting the reproductive system of birds have been described. By integrating information about the comparative anatomy and physiology of birds, reports of the most common reproductive diseases of birds and utilizing the latest diagnostic techniques, especially videoendoscopy, the avian practitioner should be able to diagnose and properly treat a high percentage of the avian reproductive diseases. 相似文献
97.
L. Marconato U. Bonfanti D. Stefanello M. R. Lorenzo G. Romanelli S. Comazzi E. Zini 《Veterinary and comparative oncology》2008,6(2):80-89
Cytosine arabinoside (ara‐C) is a component of many protocols for the treatment of acute leukaemia and non‐Hodgkin lymphomas in humans. The aim of the study was to prospectively evaluate the efficacy of ara‐C in a myeloablative regimen in a cohort of canine lymphomas with bone marrow involvement. Seventeen dogs were enrolled. Eight were treated with a VCAA‐based protocol (Group 1) and nine with the same regimen added with ara‐C (Group 2). Ara‐C was administered on a 5‐day schedule as an i.v. continuous infusion at the dose of 150 mg m?2 per day for five consecutive days. During treatment complete remission (CR) was achieved in two dogs in Group 1 and in eight dogs in Group 2. CR rate was significantly higher in Group 2 (P < 0.01). Median survival was 72.5 days (range 6–174) in Group 1 and 243 days (range 73–635) in Group 2. Survival was significantly longer in Group 2 (P < 0.001). Both protocols were well tolerated, with a low incidence of adverse events. Ara‐C added to a VCAA‐based protocol appears to be safe and beneficial in dogs with stage V lymphoma. Incorporation of the nucleoside analogue might be crucial for the development of future therapeutic strategies in dogs. 相似文献
98.
99.
100.
Artificial inoculation with fungal species involved in the Petri disease was performed on in vitro grapevine shoots. After 2 months, plantlets were observed and the presence of any leaf chlorosis or necrosis, considered as symptoms of the disease, were recorded. The fungal inoculation caused an increase in the number of symptomatic in vitro plants and in the incidence of external symptoms. Recovery of the fungal species was obtained after incubation of excised tissue fragments from the inoculated in vitro plants while some fertile fragments were collected also from plants without external symptoms. Higher levels of symptoms were observed in the rootstock varieties inoculated with Phaeomoniella chlamydospora while the lowest incidence was observed in the Aglianico cultivar. The possibility to correlate the visual assessment of in vitro plants with the data obtained by the analysis of digital images was confirmed. 相似文献