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21.
Rocha S Coutinho P Barros A Coimbra MA Delgadillo I Dias Cardoso A 《Journal of agricultural and food chemistry》2000,48(10):4802-4807
Maria Gomes and Bical are the main white grape varieties in Portuguese Bairrada Appellation, which represent 80% and 15%, respectively, of white vineyard. To estimate their aroma potentialities, free and potential volatile components from the musts were examined. The free volatile components were extracted using a liquid-liquid continuous method and were analyzed by gas chromatography-mass spectrometry. The potential volatile compounds were determined after elimination of the free components by heat and enzymatic treatments. Principal component analysis was used to establish relations between the compounds and the varieties and also the form (free or in potential). Maria Gomes has 11.5 mg/L volatile compounds, of which 33% are in free form; Bical has 4.4 mg/L volatile compounds, of which 46% are in free form. A total of 59 compounds was identified and quantified. In Maria Gomes, the sum of the terpenoids is within the perception limits for hotrienol (0.21 mg/L) and linalool (0.20 mg/L). In Bical, benzyl alcohol and phenylethylethanol represent 20% of the volatile compounds. Considering that the volatile composition pattern of Maria Gomes and Bical varieties are different, wine-making technologies should be developed specifically for each variety. 相似文献
22.
Schirra M Cabras P Angioni A Brandolini V 《Journal of agricultural and food chemistry》2002,50(6):1461-1464
Cv. Star Ruby grapefruit (Citrus paradisi Macf.) were subjected to a 3-min dip in water at room temperature (20 degrees C) or at 50 degrees C with or without 25, 50, or 100 mg/L azoxystrobin (AZX). Then, the fruits were subjected to cold quarantine at 2 degrees C and 90-95% relative humidity (RH) for 3 weeks and then stored for 5 weeks at 8 degrees C and approximately 85% RH and for another 2 weeks at 20 degrees C and 80% RH to simulate a 2-week marketing period (SMP). No AZX residues were detected in the albedo and pulp following treatments at 20 or 50 degrees C, the total amount of residues being recovered from the flavedo tissue. There was a relationship between the AZX uptake in fruit and the amount of fungicide employed at 20 or 50 degrees C. When AZX was applied to the fruit at 25 mg/L at 20 degrees C, the residue level averaged 0.11 mg/kg (active ingredient, whole fruit basis). This residue concentration increased by 50 and 75% when the application rate increased from 25 to 50 or 100 mg/L, respectively. A similar pattern of accumulation was detected in fruit subjected to treatments at 50 degrees C. However, treatments at 50 degrees C produced residue levels higher than the treatments at 20 degrees C, with increases ranging from 63 to 84%, for the same concentration. Storage conditions did not affect the amount of AZX residues in the fruit. Treatment at 50 or 100 mg/L at 20 degrees C reduced the incidence of moderate to severe chilling injury (CI). Water dips at 50 degrees C reduced the incidence and severity of CI to a very low extent, with no additional advantages when hot water was used in combination with AZX. Treatments with 50 or 100 mg/L of AZX at 20 degrees C produced beneficial effects in decay control similar to those of 25 mg/L AZX at 50 degrees C or hot water alone. Better results were achieved with 50 or 100 AZX at 50 degrees C, providing complete control of decay during cold storage and with negligible decay after SMP. It was concluded that when AZX was applied at 50 degrees C, low doses of fungicide and minimal residue levels in fruit were required to control the postharvest decay of grapefruit. This treatment does not impair fruit quality and offers very interesting prospects for large scale application, due to the reduced potential toxicity of AZX to nontarget organisms and to the environment. 相似文献
23.
Mario Augusto Pagnotta Linda Mondini Pasquale Codianni Clara Fares 《Genetic Resources and Crop Evolution》2009,56(3):299-310
Emmer wheat (Triticum dicoccon Schrank, 2n = 4x = 28) consists in a hulled wheat; its cultivation has been drastically reduced during the last century as a consequence of
its low yield. Recently, its agronomic and nutritive values, as well as the increase of popularity of organic agriculture,
have led to a renewed interest making its cultivation economically viable in the marginal lands with an increase of the cultivated
areas. In Italy, it mainly survives in few marginal lands of central and southern Italy, where local varieties, adapted to
the natural environment from where they originate, are used; moreover, some selected lines have also been developed. In the
present work, agro-morphological and qualitative traits, together with molecular analyses of 20 emmer accessions consisting
of Italian landraces, breeding lines, and cultivars, were performed. The field experiments were conducted for two consecutive
years (2001/2002–2002/2003) in two locations: Viterbo in central Italy, and Foggia in south Italy. The analyzed emmer wheat
accessions showed a good amount of genetic variability for both evaluated agro-morphological and molecular traits. This study
illustrates an increase in earliness, GY, TW, TKW, and YI going from landraces, breeding lines to cultivars, while the variability
does not change proportionally. 相似文献
24.
Atmospheric new particle formation enhanced by organic acids 总被引:4,自引:0,他引:4
Zhang R Suh I Zhao J Zhang D Fortner EC Tie X Molina LT Molina MJ 《Science (New York, N.Y.)》2004,304(5676):1487-1490
Atmospheric aerosols often contain a substantial fraction of organic matter, but the role of organic compounds in new nanometer-sized particle formation is highly uncertain. Laboratory experiments show that nucleation of sulfuric acid is considerably enhanced in the presence of aromatic acids. Theoretical calculations identify the formation of an unusually stable aromatic acid-sulfuric acid complex, which likely leads to a reduced nucleation barrier. The results imply that the interaction between organic and sulfuric acids promotes efficient formation of organic and sulfate aerosols in the polluted atmosphere because of emissions from burning of fossil fuels, which strongly affect human health and global climate. 相似文献
25.
Xiaopeng Gao Sally Parsonage Mario Tenuta Kevin Baron Krista Hanis-Gervais Alison Nelson Dale Tomasiewicz Ramona Mohr 《American Journal of Potato Research》2017,94(4):390-402
Nitrogen fertilizer practices affect nitrous oxide (N2O) emissions from agricultural soils. The “4R” nutrient stewardship framework of using N fertilizer at the right rate, right source, right placement and right time can reduce N2O emissions while maintaining or improving yield of field crops, but understanding of how the various factors affect N2O emissions from irrigated processing potato is lacking. We examined the effects of selected 4R practices on emissions, using results from two irrigated processing potato studies each conducted in 2011 and 2012 in Manitoba, Canada. Experiment 1 examined combinations of source (urea, ESN), placement (pre-plant incorporation [PPI], banding), and rate (100 and 200 kg N ha-1) on a clay loam soil. Experiment 2 examined timing and source treatment combinations (urea PPI, ESN PPI, urea split, urea split/fertigation) on a loamy fine sandy soil. For Experiment 1, use of ESN at 200 kg ha-1 did not reduce area-, yield- and applied fertilizer N- based N2O emissions compared to urea at 200 kg ha-1, irrespective of placement. Emissions from pre-plant banding ESN at 200 kg ha?1, however, were 32% lower than from PPI ESN. For Experiment 2, compared to single pre-plant urea application, fertigation simulated by in-season application of urea ammonium nitrate (UAN) gave lower area-, yield- and applied fertilizer N- based emissions. Split urea ( \( \raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) pre-plant, \( \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) hilling) also reduced area- and yield- based N2O emissions compared to single pre-plant urea application. Emissions were generally lower at the site with loamy fine sandy soil than the site with clay loam soil. These results demonstrate that combinations of “4R” practices rather than source alone are best to achieve reductions in N2O emissions from irrigated potato production. 相似文献
26.
Catherine Taverny Isabelle Ortusi Charles Roqueplo Mario Lepage Patrick Lambert 《Ecology of Freshwater Fish》2012,21(1):87-99
Abstract – Habitat requirements of lamprey ammocoetes (Petromyzon marinus and Lampetra genus) were investigated, for the first time, from shallow to deep waters, at different spatial scales across the Gironde‐Dordogne continuum, thanks to a water suction dredge. Fish‐habitat relationships were assessed through two complementary statistical analyses: habitat‐use curves and habitat suitability models using the Boosted Regression Trees (BRT) technique. Analyses were performed on a small‐size data set that was characterised by the low prevalence of lamprey. The sea lamprey larvae occurred in deeper areas than their Lampetra genus counterparts. ‘Pools’ of 2 m’ depth and more were optimal habitats for the former species. Among the environmental variables retained to model lamprey occurrences, the mesohabitat (a categorical variable) was demonstrated to be highly influential, in terms of fine grain‐size substratum and vegetation cover. These preliminary results suggest that monitoring using the water suction dredge method may contribute to sea lamprey conservation. 相似文献
27.
Chiara B. Vicentini Tiziana Poli Augusto C. Veronese Vincenzo Brandolini Maurizio Manfrini Mario Guarneri Paolo Giori 《Pest management science》1989,27(1):77-83
Twelve 6-trifluoromethylpyrazolo[3,4-d]pyrimidin-4(5H)-thiones were prepared by the reaction between 4-thiocarbamoyl-5-aminopyrazoles and trifluoroacetic anhydride. They were tested in vitro for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. The EC50 and MIC values of four compounds were comparable or inferior to those of reference commercial fungicides in controlling Sclerotinia minor, Corticium solani and Phytium ultimum. 相似文献
28.
Dutra PM Dias FA Santos MA Rodrigues CO Romeiro A Attias M De Souza W Lopes AH Meyer-Fernandes JR 《Phytopathology》2001,91(4):408-414
ABSTRACT The secreted phosphatase activities of two trypanosomatid parasites were characterized and compared with supernatants of living cells. The plant parasite Phytomonas fran?ai and the phytophagous hemipteran parasite Herpetomonas sp. hydrolyzed p-nitrophenylphosphate at a rate of 15.54 and 6.51 nmol Pi/mg of protein per min, respectively. Sodium orthovanadate (N(a)VO(3)) and sodium fluoride (NaF) decreased the phosphatase activities. The phosphatase activity of P. fran?ai was drastically diminished (73% inhibition) in the presence of sodium tartrate, whereas the phosphatase activity of Herpetomonas sp. was inhibited by 23%. Cytochemical analysis showed the localization of these enzymes on the external surface and in the flagellar pocket of the two trypanosomatids. Sodium tartrate inhibited this reaction, confirming the biochemical data. Platelet-activating factor modulated the phosphatase activities, inhibiting P. fran?ai activity and stimulating Herpetomonas sp. phosphatase activity. 相似文献
29.
Chiara B. Vicentini Vincenzo Brandolini Tiziana Poli Mario Guarneri Paolo Giori 《Pest management science》1992,34(2):127-131
3-Methyl-5-(acyl/alkyl)aminoisoxazole-4-thiocyanates were prepared by rhodanation of N-acyl/alkyl-3-methyl-5-isoxazolamines. These products were tested for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. Some of the compounds showed interesting in-vitro activity. The more active compound in the in-vitro test displayed a moderate preventive activity against Plasmopara viticola, Alternaria solani and Pyricularia recondita. 相似文献
30.
Irene Abbattista Gentile Lucia Ferraris Mario Sanguinetti Marinela Tiprigan Giuseppina Fisichella 《Pest management science》1992,34(3):297-301
The effect of some physical factors on the processes (hydrolysis, volatilisation) regulating the persistence of methyl bromide in fresh surface waters was investigated to complement previous research. It has been confirmed that electromagnetic radiation in the visible field has no influence on the hydrolysis kinetics of the fumigant. The removal of methyl bromide by volatilisation from stirred and ventilated solutions appears to be of greater importance in practice. It has been shown that under these conditions the half-life is directly proportional to the liquid depth. Without stirring volatilisation is greatly reduced, due to the low diffusivity of methyl bromide in the aqueous phase. 相似文献