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191.
Summary The effects of phosphate-solubilizing bacteria on the phosphorus mobilization and P utake by Lolium multiflorum from a calcareous soil were investigated using a greenhouse pot experiment. The soil was inoculated with Bacillus cereus and the pots were either planted with Lolium multiflorum or left fallow. Treatments were designed to study the effect of inoculation of phosphate-solubilizing bacteria on phosphorus dynamics throughout the experiment. The dynamics were studied by the electro-ultrafiltration method, the results of which were used to interpret phosphorus mobilization in the soil. Phosphate uptake by L. multiflorum from the inoculated soil showed a 40% increase over the control soil, and an increase in total dry matter of 50%. 相似文献
192.
Marisa Nordenstahl Pedro E. Gundel M. Pilar Clavijo Esteban G. Jobbágy 《Agroforestry Systems》2011,83(2):201-211
In managed rangelands periods of low primary productivity determine troughs of forage availability, constraining animal production
year-round. Although alternative tools to increase forage availability during critical seasons exists, most of them are unaffordable
and short-lived in marginal areas. We explore the potential benefits of deciduous tree plantations favoring winter forage
productivity by comparing aboveground net primary productivity (ANPP) patterns in herbaceous understory to tree plantations
and natural grasslands in the Pampas (Argentina). These temperate subhumid grasslands are characterized by the coexistence
of winter species, mainly C3 grasses of the native genera Stipa, Piptochaetium, and Bromus and the exotic genera Lolium and Festuca) and summer species (mainly C4 grasses of the native genera Paspalum, Bothriochloa, and Stenotaphrum) that replace each other throughout the seasons, with domination of the latter. We hypothesize that the natural decoupling
of growing seasons between winter deciduous trees and winter grasses could provide the basis for the sustainable promotion
of winter forage. We measured ANPP on two 23-year-old Populus deltoides plantations and their understory and compared them with adjacent open grasslands. Afforested stands had 55–75% higher annual
ANPP than their non-afforested neighbors, with trees contributing ~70% to total ANPP. Herbaceous canopies beneath plantations
achieved about half of the ANPP observed in non-afforested situations with a contrasting seasonal distribution associated
with shifts from C4 to C3 grass dominance. Winter ANPP, the most critical source of forage in these grazing systems, was similar
or higher in the herbaceous understory of tree plantations to that on their non-afforested counterparts, suggesting that mixed
systems involving deciduous trees and understory pastures are a valid and viable option in the region. 相似文献
193.
Driving AMPA receptors into synapses by LTP and CaMKII: requirement for GluR1 and PDZ domain interaction 总被引:1,自引:0,他引:1
Hayashi Y Shi SH Esteban JA Piccini A Poncer JC Malinow R 《Science (New York, N.Y.)》2000,287(5461):2262-2267
To elucidate mechanisms that control and execute activity-dependent synaptic plasticity, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPA-Rs) with an electrophysiological tag were expressed in rat hippocampal neurons. Long-term potentiation (LTP) or increased activity of the calcium/calmodulin-dependent protein kinase II (CaMKII) induced delivery of tagged AMPA-Rs into synapses. This effect was not diminished by mutating the CaMKII phosphorylation site on the GluR1 AMPA-R subunit, but was blocked by mutating a predicted PDZ domain interaction site. These results show that LTP and CaMKII activity drive AMPA-Rs to synapses by a mechanism that requires the association between GluR1 and a PDZ domain protein. 相似文献
194.
Aguilera Y Dueñas M Estrella I Hernández T Benitez V Esteban RM Martín-Cabrejas MA 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(2):187-195
This study presents the effects of soaking, cooking and industrial dehydration on the phenolic profile, and antioxidant capacity
in two chickpea varieties (Sinaloa and Castellano). Chromatographic analysis identified a total of 24 phenolic components,
being isoflavones the main phenolics in raw and processed Sinaloa and Castellano flours. The impact of the industrial dehydration
was different depending on the chickpea variety. Although Castellano chickpea exhibited the highest levels of phenolic compounds
(103.1 μg/g), significant reductions were observed during processing; in contrast, the dehydration did not cause any further
effects in Sinaloa flours. Interestingly, Sinaloa variety showed high thermal stability of isoflavones during processing.
As expected, the levels of antioxidant capacity were in accordance with the behavior of phenolic compounds exhibiting noticeable
reductions in Castellano chickpea and not relevant changes in Sinaloa chickpea. Thus, the significant occurrence of bioactive
phenolic compounds along with the relevant antioxidant capacities of dehydrated chickpea flours make them to be considered
functional ingredients for their beneficial health effects, especially in case of Sinaloa. 相似文献
195.
White lupine is an As-resistant legume that is of interest for phytoremediation of As-contaminated soils. To achieve successful phytoremediation, monitoring of the nutritional status of the selected plant species during the entire culture cycle is required to maintain a plant cover with high biomass production. A long-term pot experiment was carried out with nodulated lupine grown on perlite with 10 and 100 microM As concentrations. The reproductive period (from 10 weeks) was the most sensitive phenologic stage of white lupine to long-term As exposure. The 10 microM As treatment increased the uptake and translocation of micronutrients, except for Cu, mainly at flowering with As levels in pods below the statutory limit (1 mg kg (-1) fresh weight). However, the 100 microM As treatment induced significant differences compared to the control. These findings confirm the relatively high resistance of white lupine to arsenate and support the use of this species in phytoremediation and/or revegetation of As-contaminated sites, with special attention on P and Cu nutrition at flowering. 相似文献
196.
Ignacio A. Ciampitti Esteban A. Ciarlo Marta E. Conti 《Biology and Fertility of Soils》2008,44(4):581-588
The purpose of this study was to evaluate, during the phenological stages of inoculated soybean crop [Glycine max (L.) Merrill], the effect of different N fertilization levels and inoculation with Bradyrhizobium japonicum on N2O emissions from the soil. Gas emissions were evaluated at field conditions by the static-chamber method. Nitrogen fertilization
increased N2O emissions significantly (P < 0.05). The variable that best explained cumulative N2O emissions during the whole soybean growing season was the soil nitrate level (r
2 = 0.1899; P = 0.0231). Soil moisture presented a greater control on N2O emissions between the grain-filling period and the crop commercial maturity (r
2 = 0.5361; P < 0.0001), which coincided with a positive balance of the available soil N, as a consequence of the decrease in crop requirements
and root and nodular decomposition. Only soil soluble carbon (r
2 = 0.29; P = 0.019) and moisture (r
2 = 0.24; P = 0.039) were correlated with N2O emissions during the residue decomposition period. The relationship between soil variables and N2O emissions depended on crop phenological or stubbles decomposition stages. 相似文献
197.
Díaz-Maroto MC Pérez-Coello MS Esteban J Sanz J 《Journal of agricultural and food chemistry》2006,54(18):6814-6818
Comparison of the volatile composition of fennel (Foeniculum vulgare Mill.) has been carried out using direct thermal desorption (DTD) coupled to gas chromatography-mass spectrometry. Forty-two wild fennel stem samples were collected in two different geographical areas of Central Spain. DTD allowed a high recovery of volatiles from small sample sizes without thermal decomposition. trans-Anethole was the main volatile compound for most cases, although a high variability was found among samples, showing clear phytochemical differences. 相似文献
198.
Alberto Díaz Dapena Esteban Fernández Vázquez Fernando Rubiera Morollón 《Growth and change》2018,49(1):55-70
In this paper, Ciccone's ( 2002 ) approach is applied to the Spanish case in 2011 but by estimating it using local labor markets (LLMs) instead of NUTS‐2 or NUTS‐3 regions. It is especially relevant in the case of Spain because the NUTS‐3 (provinces) are large regions in comparison with other cases in Europe. From a sample of income taxpayers published by the Spanish Fiscal Studies Institute, we derive figures on average wages by worker on the scale of LLMs. We argue that working at this level of spatial disaggregation is more in line with the idea of externalities from agglomerations, which are generated on a local scale. We can also observe intra‐regional heterogeneity and how the urban wage premium changes along the entire distribution of cities, including small‐medium size urban areas or rural areas. The empirical analysis is based on several estimation strategies, namely, ordinary least squares, two‐stages least squares, quantile regressions (QR), and instrumental variable quantile regressions (IVQR) estimators; they all find a significantly positive effect of agglomeration in the conditional mean of wages. This result can be estimated along the conditional distribution of wages. According to the QR and IVQR estimates, important variations are found along the distribution. 相似文献
199.
Interaction of Beauveria bassiana and Metarhizium anisopliae with chlorpyrifos ethyl and spinosad in Spodoptera frugiperda larvae
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200.
Cristina?SimónEmail author Luis?García?Esteban Paloma?de?Palacios Francisco?García?Fernández Alberto?García-Iruela Raquel?Martín-Sampedro María?E.?Eugenio 《Wood Science and Technology》2017,51(3):517-534
The hygroscopicity and thermodynamic properties of Pinus canariensis wood buried in volcanic ash, dating from 1100 BC, were studied and compared with recently felled juvenile and mature wood of the same species. The sorption isotherms were obtained by the saturated salt method at 35 and 50 °C. The isotherms were fitted using the Guggenheim–Anderson–de Boer model. The thermodynamic parameters were determined following the Clausius–Clapeyron integration method. To understand the behaviour of each type of wood, the chemical composition, infrared spectra and X-ray diffractograms were determined for each sample. The mature wood has a higher sugar content and lower extractive content than the juvenile and the buried wood. For both temperatures, the isotherm of the mature wood is above the isotherm of the juvenile wood and this, in turn, is above the isotherm of the buried wood, primarily influenced by the higher cellulose and hemicellulose contents and lower extractives content in the mature wood, resulting in a higher number of accessible –OH groups. Degradation of the buried wood due to high temperatures explains why its isotherms are below the isotherms of the recent wood. The energy involved in the desorption process is greater than in adsorption. Similarly, more energy is involved in the mature wood than in the juvenile wood, and the energy involved in the juvenile wood is greater than in the buried wood. 相似文献