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91.
Pissarra J Lourenço S González-Paramás AM Mateus N Santos Buelga C Silva AM de Freitas V 《Journal of agricultural and food chemistry》2004,52(17):5519-5526
The condensation reaction between malvidin 3-glucoside and catechin mediated by isobutyraldehyde, benzaldehyde, and isovaleraldehyde was conducted in model solutions at two pH values (1.5 and 3.2). The formation of new alkyl/aryl-linked adducts corresponding to the structures malvidin 3-glucoside-isobutylcatechin, malvidin 3-glucoside-benzylcatechin, and malvidin 3-glucoside-3-methylbutylcatechin was respectively observed from each aldehyde. The structural characterization of these new structures has been elucidated by 1D and 2D NMR, mass spectrometry, and UV-vis techniques. These new adducts showed the same lambda(max) in the visible region at 540 nm, which is bathochromically shifted 15 nm when compared with the original anthocyanin (lambda(max) = 525 nm). 相似文献
92.
Geraldo Resende Boaventura Ana Luiza Saboia De Freitas 《Water, air, and soil pollution》2006,171(1-4):135-151
In Brazilian Tropical Cerrado Region, reactions related to parental-material breakdown and oxisols genesis strongly affect the groundwater chemical characteristics. These reactions are responsible for the low water pH values, the soil charge balance, and the re-equilibrium of dissolved inorganic carbon species. Brasilia, the capital of Brazil, lies in the Distrito Federal, in the central part of the Brazilian Cerrado Region and has been experiencing an intense urban development during the last 15 years. Many town-house complexes have been built without proper water supply or wastewater disposal conditions. In this work, we discuss the adequacy of traditional ground waters geochemical classification models applied to the most exploited aquifers in DF. Forty groundwater samples were collected and pH, conductivity and total dissolved solids were determined in the field. Na, K, Ca, Mg, Fe, Al, Cu, Cd, Cr Mn e Zn were determined by Inductively Coupled Plasma Atomic Emission Spectrometry and Atomic Absorption Spectrophotometry. We identify inorganic indicators of human interference on the quality of these waters and also suggest a new mean of interpretation of dissolved inorganic elements based on statistic treatment of multivariate data. It is revealed a particular geochemical feature concerning to the alkali and the earth alkali metals concentrations, and a typical trace-element behaviour, closely related to the human activities and to the geological-bearing material characteristics. For all of the samples supposed to be altered by any kind of human activity, the physico-chemical parameters were lower than the standards established by the water quality legal system. 相似文献
93.
Márcia G. Ventura Maria Do Carmo Freitas Adriano M. G. Pacheco 《Water, air, and soil pollution》2005,166(1-4):167-179
Selenium contents in the Portuguese (mainland) territory, resulting from a few environmental studies held since 1990 using lichens, vascular plants, soils and air particulate matter (APM), are presented and discussed herein. Values for Se in soils, epiphytic lichens and higher plants are within the typical ranges found in the literature. Compared to vascular plants, lichens display higher contents at the same locations. In what concerns Se in airborne particulates, all surveyed sites show values that are typical of urban areas. In two of such sites – Monchique and Carregado – Se concentrations in transplanted lichen thalli of the Parmelia genus (mostly, Parmelia sulcata Taylor) were compared to the results obtained from airborne matter, and a good correlation was found for the corresponding data-sets at either location. Other than the degree of association, it is especially noteworthy that the lichen transplants appear to accumulate much more Se at Monchique (a remote, rather clean site) than at Carregado (in the immediate vicinity of an oil-fired, power plant), even if its amount in the atmosphere is lower at the former location. 相似文献
94.
95.
Emiliana O. S. Batista Lais M. Vieira Bruno G. Freitas Bruna M. Guerreiro J. G. S. Carvalho Rodolfo D. Mingoti Guilherme Vasconcellos Alexandre H. Souza Jose Bento Sterman Ferraz Pietro Sampaio Baruselli 《Reproduction in domestic animals》2020,55(6):753-758
This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success. 相似文献
96.
97.
Sara Margarida Mendes Joaquim Santos Helena Freitas José Paulo Sousa 《Agroforestry Systems》2011,82(2):139-148
Cork oak “Montados” are a particular Mediterranean ecosystem, which can be found in Southern Portugal. Portuguese “Montados”
are man-made ecosystems, mainly used for cork production and cattle farming, that support a high biological diversity. Current
sustainable management techniques imply a shrub clearing with heavy machinery, which can be highly disruptive for soil biota.
In order to evaluate the effects of understory vegetation management on soil epigeic macrofauna, five zones were defined along
a chronosequence of shrub clearing: a non-disturbed zone (zone 5) and zones where understory vegetation was cut at 4–5 years
(zone 4), at 3–4 years (zone 3), at 2 years (zone 2) and at 1 year (zone 1). A sixth zone (zone 6) was selected in a pasture,
where cattle are occasionally present. Soil fauna was sampled using “pitfall” traps and sampling took place in autumn 2003.
A total of 2,677 individuals, separated into 152 species and morphospecies, were caught in the traps. With the exception of
zone 6, that presented a lower number of species, all the other zones from the chronosequence presented, in most cases, a
similar number of taxa, species diversity (Shannon) and species richness (Margalef). Multivariate analysis separated recently
disturbed zones (plus zone 6) from those intervened at longer time; groups like Formicidae, Scydmaenidae, most families from
Araneae and insect larvae appeared closely associated to zones 3–5 (with a higher shrub cover and thick litter layers), whereas,
other Hymenoptera, Gastropda and most Coleoptera families, appeared associated to recently disturbed zones (zones 1 and 2)
and to zone 6, characterized by a lower shrub cover and a lower accumulation of litter. This separation indicates that effects
of the intervention can endure for 2 or 3 years. After that time, the normal natural regeneration of the understory vegetation
seems to support the restoration of the macrofauna community, thus indicating that the sustainable management strategy adopted,
i.e., making a shrub cut every 5–6 years, seems not induce a significant effect on local species richness of soil epigeic
macrofauna. 相似文献
98.
99.
Mateus N Carvalho E Carvalho AR Melo A González-Paramás AM Santos-Buelga C Silva AM De Freitas V 《Journal of agricultural and food chemistry》2003,51(1):277-282
Three newly formed pigments were detected and isolated from a 2-year-old Port wine through TSK Toyopearl HW-40(S) gel column chromatography and characterized by UV-visible spectrophotometry, NMR, and mass spectrometry (ESI/MS). (1)H NMR and (13)C NMR data for these pigments obtained using 1D and 2D NMR techniques (COSY, NOESY, gHSQC, and gHMBC) are reported for the first time. The structure of the pigments was found to correspond to the vinyl cycloadducts of malvidin 3-coumaroylglucoside bearing either a procyanidin dimer or a flavanol monomer ((+)-catechin or (-)-epicatechin). Additionally, conformational analysis was performed for one of these newly formed pigment using computer-assisted model building and molecular mechanics. A chemical nomenclature is proposed to unambiguously name this new family of anthocyanin-derived pigments. 相似文献
100.
Rodrigues D Santos CH Rocha-Santos TA Gomes AM Goodfellow BJ Freitas AC 《Journal of agricultural and food chemistry》2011,59(9):4955-4961
To assess ripening of potential probiotic cheeses (containing either Lactobacillus casei -01 or Bifidobacterium lactis B94) or synbiotic cheeses with fructooligosaccharides (FOS) or a 50:50 mix of FOS/inulin, metabolic profiles have been obtained via classical biochemical analyses and by NMR spectroscopy. The addition of prebiotics to the cheeses resulted in lower proteolysis indices, especially in those synbiotic cheeses inoculated with B. lactis B94. Among synbiotic cheeses the combination of FOS and inulin resulted in an increase in lipolytic activity. The metabolic profiles of the cheeses analyzed by NMR spectroscopy, combined with multivariate statistics, allowed profiles to be distinguished by maturation time, added probiotic bacteria, or, in the case of B. lactis B94 cheese, added prebiotic. The NMR results are in agreement with the biochemical analyses and demonstrate the potential of NMR for the study of metabolic processes in probiotic/synbiotic food matrices. 相似文献