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21.
David Domínguez Zakarya Sehnine Pedro Castro Lidia Robaina Ramon Fontanillas Philip Antony Jesu Prabhu Marisol Izquierdo 《Aquaculture Nutrition》2020,26(2):579-589
Substitution of marine ingredients (FM‐FO) by plant protein and oil sources can modify selenium (Se) levels in feeds. Se plays an important role in the antioxidative defence by forming part of selenoproteins. Se requirements of gilthead sea bream are not accurately determined; therefore, this study was conducted to define Se supplementation levels in low FM‐FO practical diets for sea bream fingerlings. A plant‐based diet containing 0.45 mg Se/kg diet was used as the basal diet. Four other diets were supplemented to contain 0.68, 0.86, 1.00 or 1.70 mg Se/kg diet, supplied as sodium selenite. Sea bream, weighing 12.6 ± 1.4 g, were distributed in triplicate groups per diet and fed for 42 days. Se supplementation up to 1.00 mg Se/kg significantly improved the growth of sea bream, whereas further increase up to 1.70 mg Se/kg diet reduced growth. The results of this study suggest that the optimum dietary levels of sodium selenite in diets with low FM‐FO with basal levels of 0.45 mg Se/kg are around 0.94 mg Se/kg to promote growth of gilthead sea bream juveniles. On the contrary, dietary levels of 1.70 mg Se/kg were found to be excessive and caused growth reduction, increased catalase expression and hydropic degeneration in the liver. 相似文献
22.
Post-fire resprouting ability of the non-dominant tree and shrub species of the Mediterranean Basin has not yet been experimentally tested, although this group contributes to maintain the richness of Mediterranean plant communities. In this study, we have analyzed the post-fire recovery ability of 15 woody species that occur in relatively low abundance in dry and sub humid Mediterranean areas in NE of Spain. The main goals have been: (i) to determine experimentally the post-fire resprouting ability of these species and (ii) to compare the abundance of these species in areas affected by wildland fires and in unburned areas. We have observed a high resprouting ability after prescribed burning of most species except for Juniperus communis and J. phoenicea which showed a null resprouting. As the species with high resprouting ability showed similar presence in burned and unburned areas, we can conclude that wildfires are not a factor that constrains the presence of these species in Mediterranean woodlands. However, we found a reduction in the abundance of J. communis and J. phoenicea at the regional level after wildland fires. 相似文献
23.
Dionisio Lidia P. C. Garcia-Rosado Esther Lopez-Cortes Lourdes Castro Dolores Borrego Juan J. 《Water, air, and soil pollution》2002,138(1-4):319-334
Three microbiological criteria (European Economic Community,World Health Organization/United Nations Environment Programand European Union) for water quality have been comparativelyevaluated in a resort zone of southern Portugal, located atthe Ria Formosa (Algarve). The results obtained in this studysuggest that the three compared directives adequatelyclassified the bathing zones according to their fecalpollution level. However, none of the directives establish asanitary classification of the recreational use of the bathingzones. By the use of the Cumulative Contamination Indexapplied in this study, classification based on both the levelof fecal pollution and on the sanitary condition of thebathing zones has been achieved. The application of this newapproach to the monitoring of bathing waters allows us topropose a new criterion of water quality based on thecoliphage levels (Ph80 = 300 pfu 100 mL-1 and Ph95 = 2000 pfu 100 mL-1) for inclusion in the newwater quality regulations. Coliphages have been shown to havea close correlation with the presence of pathogenic microorganisms, and with the fecal pollution levels of recreational seawaters. However, none of the microbial indicatorstested ensured detection of pathogen presence. 相似文献
24.
Francesca Mercati Paula Domingo Rolando Pasquariello Cecilia Dall'Aglio Alessandro Di Michele Katia Forti Paolo Cocci Cristiano Boiti Lidia Gil Massimo Zerani Margherita Maranesi 《Reproduction in domestic animals》2020,55(1):29-37
Freeze-drying (FD) has been exhaustively tried in several mammalian species as an alternative technique to sperm cryopreservation, but few studies have been done in rabbits (Oryctolagus cuniculus). The main objective of this study was to compare the protective effect of various antioxidants added to EDTA medium on structural and functional components of FD rabbit spermatozoa and on their status of global DNA methylation. FD media used were composed of basic FD medium (10 mM Tris-HCl buffer and 50 mM NaCl) supplemented with either 50 mM EDTA alone (EDTA) or added with 105 µM of rosmarinic acid (RA, EDTA-RA) or 10 µM of melatonin (MLT, EDTA-MLT). The effect of each medium on the preservation of FD spermatozoon structure was evaluated with light and scanning electron microscopy (SEM). Global DNA methylation was quantified in all FD sperm samples as well as in fresh spermatozoa. Morphologically, fracture points were evidenced in the neck, mid and principal piece of the spermatozoon tail. No differences in spermatozoon fracture points were evidenced among FD treatments: intact spermatozoa were the largest (p < .01) category, whereas the most frequent (p < .01) injury was the neck fracture, resulting in tailless heads. At SEM, the head of spermatozoa showed a well-conserved shape and intact membrane in all treatments. DNA methylation status was the same in all FD treatments. In conclusion, supplementation of EDTA, EDTA-RA and EDTA-MLT during FD preserved rabbit sperm morphological integrity and methylation status as well. Therefore, the difficulty of getting viable offspring using FD semen is likely unrelated to the impact of the lyophilization process on DNA methylation and morphology of lyophilized spermatozoa. 相似文献
25.
Underwater noise pollution is a growing problem in aquatic environments and as such may be a major source of stress for fish. In the present study, we addressed the effects of ship noise and continuous Gaussian noise on adrenal activity in three European freshwater species. Underwater ship noise recorded in the Danube River and two Austrian lakes was played back to fish at levels encountered in the field (153 dB re 1 μPa, 30 min). Post exposure cortisol secretion was compared with control situations. Cortisol was measured with enzyme immunoassay techniques (EIA, ng cortisol/l water/g fish) in extracted aquarium water with corrections for fish mass. In the first series, two hearing specialists, the common carp (Cyprinus carpio) and the gudgeon (Gobio gobio) and one hearing generalist, the European perch (Perca fluviatilis) were exposed to ship noise. The noise level was well above hearing thresholds in these species. In a second series, fish were exposed to continuous Gaussian noise at a similar level (156 dB) which is known to induce temporary hearing loss in hearing specialists. All three species responded with increased cortisol secretion when exposed to ship noise. Interestingly, no elevation was observed when fish were exposed to continuous Gaussian noise. Our results indicate that ship noise characterized by amplitude and frequency fluctuations, constitutes a potential stressor in contrast to continuous noise. Surprisingly, the data also demonstrate no apparent differences between species possessing excellent hearing abilities (hearing specialists) and species with poor hearing abilities like perch. 相似文献
26.
Particle size fraction(clay, silt, and sand) is an important characteristic that influences several soil functions. The laser-diffraction method(LDM) provides a fast and cost-effective measurement of particle size distribution, but the results usually differ from those obtained by the traditional sieve-pipette method(SPM). This difference can persist even when calibration is applied between the two methods. This partly relates to the different size ranges of particles measured by the two methods as a result of different operational principles, i.e., particle sedimentation according to Stokes’ Law vs. Mie theory for laser beam scattering. The objective of this study was to identify particle size ranges of LDM equivalent to those measured by SPM and evaluate whether new calibration models based on size range correction can be used to improve LDM-estimated particle size fractions, using 51 soil samples with various texture collected from five soil orders in New Zealand. Particle size distribution was determined using both LDM and SPM. Compared with SPM, original data from LDM underestimated the clay fraction(< 2 μm), overestimated the silt fraction(2–53 μm), but provided a good estimation of the sand fraction(53–2 000 μm).Results from three statistical indices, including Pearson’s correlation coefficient, slope, and Lin’s concordance correlation coefficient, showed that the size ranges of < 2 and 2–53 μm defined by SPM corresponded with the < 5 and 5–53 μm size ranges by LDM, respectively. Compared with the traditional calibration(based on the same particle size ranges), new calibration models(based on the corrected size ranges of these two methods) improved the estimation of clay and silt contents by LDM. Compared with soil-specific models(i.e., different models were developed for different soils), a universal model may be more parsimonious for estimating particle size fractions if the samples to be assessed represent multiple soil orders. 相似文献
27.
Im Agraratlas des Landes Sachsen‐Anhalt werden für raumstrukturelle Entscheidungen natürliche und ökonomische Faktoren und Bewertungen in ihrer regionalen Anordnung dargestellt. Der vorliegende Beitrag bezieht sich auf den Teilkomplex “Gemeindebezogene Standortinformationen”; und beinhaltet methodisches Vorgehen und Ergebnisse zu den thematischen Karten: Geologische Substratherkünfte, Hangneigungsverhältnisse, Hydromorphieverhältnisse, Steinigkeit, Bodenbedingte Anbaueignung, Substratbedingte Bewirtschaftungseignung und Potentielle Gefährdung für Wasser‐ und Winderosion. Zu den Karteninhalten werden tabellarisch gemeindebezogene Häufigkeiten von Legendeneinheiten und Flächenangaben zum Vorkommen von Merkmals‐ und Beurteilungsklassen mitgeteilt. 相似文献
28.
Maia Fradkin María Rosa Ferrari Víctor Ferreira Ezequiel Martín Grassi Eduardo José Greizerstein Lidia Poggio 《Genetic Resources and Crop Evolution》2012,59(2):231-237
Triticum–Thinopyrum amphiploids arose from the need to obtain forage grasses highly resistant to pest, drought, soil salinity and frost and they
can be used as efficient bridges to transfer desired genes from wheatgrass species to wheat. One of them is trigopiro SH16
INTA, it was introduced in Argentina in 1947 but its genomic composition was unknown. The aim of this work was to determine
the chromosome number and genomic and chromosome composition of trigopiro SH16 INTA in order to use it in breeding programs.
The simultaneous use of the in situ hybridization technique with different probes (genomic DNA of Th. ponticum (Podp.) Barkworth et D.R. Dewey, pSc119.2 and pAs1) allowed us to conclude that the chromosome number of trigopiro SH16 is
2n = 42 and the genome composition would be: 14 chromosomes of the B genome, the 2D and 4D chromosome pairs of wheat, 14 chromosomes
of the J genome of Thinopyrum and the remaining chromosomes probably belong to the A genome of wheat. 相似文献
29.
Emmanouil Roditakis Christina Skarmoutsou Marianna Staurakaki María del Rosario Martínez‐Aguirre Lidia García‐Vidal Pablo Bielza Khalid Haddi Carmelo Rapisarda Jean‐Luc Rison Andrea Bassi Luis A Teixeira 《Pest management science》2013,69(2):217-227
BACKGROUND: Tuta absoluta(Meyrick) is one of the most serious pests of tomato recently introduced in the Mediterranean region. A novel bioassay method designed for the accurate determination of insecticide toxicity on T. absoluta (IRAC method No. 022) was validated by three different laboratories [Greece (NAGREF), Italy (UC) and Spain (UPCT)] on European populations. RESULTS: The insecticides indoxacarb and chlorantraniliprole were used as reference products. The IRAC leaf dip method is easy to perform, producing repeatable, homogeneous responses. LC50 values for indoxacarb ranged between 1.8 and 17.9 mg L?1 (NAGREF), 0.93 and 10.8 mg L?1 (UC) and 0.20 and 0.70 mg L?1 (UPCT), resulting in a tenfold, 12‐fold and fourfold difference between the least and most susceptible populations at each laboratory respectively. For chlorantraniliprole, LC50 values ranged between 0.10 and 0.56 mg L?1 (NAGREF), 0.23 and 1.34 mg L?1 (UC) and 0.04 and 0.24 mg L?1 (UPCT), resulting in a sixfold difference in all three cases. Overall, UPCT reported lower mean LC50 to indoxacarb, while UC reported higher LC50 to chlorantraniliprole. CONCLUSIONS: The new bioassay is reliable, providing a useful tool in the design of IRM strategies. Within each country/lab, the variability observed in the results for both indoxacarb and chlorantraniliprole can be attributed to natural variation. Future research is necessary to determine the extent to which it is possible to compare results among laboratories. Copyright © 2012 Society of Chemical Industry 相似文献
30.
Moreno AO Dorantes L Galíndez J Guzmán RI 《Journal of agricultural and food chemistry》2003,51(8):2216-2221
Because Mexico is the number one producer of avocados in the world, this fruit has potential as a source for oil extraction. It is appropriate to further investigate the detailed changes that the oil undergoes when different extraction methods are applied. This research paper presents the study of the physical and chemical changes, the fatty acids profile, the trans fatty acid content, and the identification of volatile compounds of the oils from avocado pulp (Persea americana Mill.), obtained by four different extraction methods. The method with the greatest extraction yield was the combined microwave-hexane method. The amount of trans fatty acids produced in the microwave-squeezing treatment was <0.5 g/100 g. On the other hand, the amounts of trans fatty acids produced with the hexane and acetone treatments were 0.52 and 0.87 g/100 g, respectively. The method that caused the slightest modification to the oil quality was a novel combined extraction method of microwave-squeezing proposed by the authors. 相似文献