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51.
Wheat is a good source of polyphenols, plant metabolytes with beneficial effects on human health. However, little information is available on phenolic acid composition and concentration in different Triticum species, as well as on possible environmental effects. To shed some light on this issue, thirty-nine wheat accessions cropped for two years and belonging to different Triticum species (Triticum monococcum, Triticum turgidum ssp. dicoccum, turanicum and durum, Triticum aestivum ssp. spelta and aestivum) were assessed for phenolic acids (ferulic, p-coumaric, vanillic, syringic, p-hydroxybenzoic, caffeic acids and syringaldehyde), total polyphenols and antioxidant activity in soluble conjugated and insoluble bound extracts. Ferulic acid was the most abundant compound in both extracts. Insoluble bound phenolic acids represented >90% of total phenolic acids. Einkorn showed the maximum concentration of conjugated phenolic acids (50.5 mg/kg DM), while durum and bread wheats presented the highest content of bound phenolic acids (651.8 and 629.2 mg/kg DM, respectively). Cropping year influenced the concentration of conjugated but not of bound phenolic acids. A survey of phenolic acid distribution in the kernel showed that they are rare in endosperm, but abundant in germ and bran. Total polyphenols and antioxidant activity were highly correlated to phenolic acid content.  相似文献   
52.
To limit nutritional losses and optimise bread processing, heat damage indices (furosine, glucosylisomaltol, hydroxymethylfurfural), sugars, α-amylase, β-amylase and colour were monitored during bread manufacturing from refined flour of three einkorn, three bread and one durum wheat samples. The heat damage indices increased only during the baking step. Furosine was significantly lower in einkorn (on average, 9.3 ± 5.33 and 25.3 ± 10.70 mg/100 g protein in crumb and crust, respectively) than in bread wheat (31.6 ± 3.05 and 115.6 ± 13.53) and durum wheat (36.2 ± 2.82 and 165.0 ± 3.17). Glucosylisomaltol and hydroxymethylfurfural were detected only in the crust, with lower levels in einkorn (on average, 2.3 ± 1.78 and 10.0 ± 7.79 mg/kg DM, respectively) than in bread wheat (13.1 ± 5.57 and 42.8 ± 10.64) and durum wheat (18.9 ± 1.11 and 57.2 ± 0.80). The different behaviour of einkorn was probably related to its moderate β-amylase activity, and thus the low maltose content of its dough. Colour was correlated with heat damage, as einkorn breads were lighter than the others.The results show that einkorn bread undergoes lower heat damage than analogous products from durum and bread wheat, thus probably better preserving its nutritional value.  相似文献   
53.
To evaluate the effect of genotype, year and location on 1000 kernel weight, falling number, alpha- and beta-amylase activity, pasting properties, β-glucan, fructan, total starch, amylose, resistant starch and dietary fibre contents of wholemeal flour, four einkorns and one control bread wheat were cropped in Italy for two years in four different locations.  相似文献   
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55.
For efficient integrated management of verticillium wilt in olive (VWO), it is important to establish whether irrigation treatments (with Verticillium dahliae‐free water) that mitigate the disease in V. dahliae‐infested soil, also reduce the levels of more and less persistent propagules of the pathogen in the soil. Effects of irrigation on VWO and V. dahliae propagules were evaluated under natural environmental conditions. Potted plants were irrigated (pathogen‐free water) to two ranges of soil water content (RWC; high and low) at three surface drip‐irrigation frequencies (daily, weekly, and daily during some periods and otherwise weekly). VWO and total inoculum density (ID), density of less persistent micropropagules (MpD) and more persistent sclerotia in wet soil (SwD), and sclerotia density for air‐dried soil (SdD) were monitored. A logistic model (multiple sigmoid) of disease incidence revealed the lowest parameter values in treatments irrigated daily. Daily frequency of irrigation showed significantly lower disease incidence (39.2%) and disease intensity index (43.9%) and MpD (88.0%) values as areas compared with other frequencies, regardless of the RWC. High RWC significantly reduced (70.8–84.9%) ID, SwD and SdD as areas, but significantly increased (18.0%) the incidence of infected plants (IIP), regardless of the irrigation frequency. The disease incidence was not correlated with temperature. Daily irrigation to low RWC mitigated the VWO and the IIP, kept soil to the lowest MpD and resulted in the lowest SdD level at the end of the trial. Results suggested that less persistent propagules could have played a part in the disease development.  相似文献   
56.
Pinus species, which have formed the foundation of commercial forestry industry in many countries, are known to be invasive in natural ecosystems, especially in the Southern Hemisphere. Pinus contorta is considered one of the most aggressively invasive plantation species. In this paper we aim to: (a) determine patterns of P. contorta invasion in relation to its size and age structure and spatial distribution and (b) determine the effect of vegetation cover on its regeneration. For this purpose, we have chosen the Malalcahuello National Reserve in south-central Chile, which is dominated by Araucaria araucana forests. In the three P. contorta trial plots, attributes were measured in order to describe its current structure. We selected one of the three P. contorta trial plots and set eight 50 m wide and 125 m centrifugal transects starting at the North Azimuth (0°) orientation and then one each 45°. In each transect 25 circular plots of 2.5 m radius were established every 25 m. In each plot, we measured collar diameter (CD) for each P. contorta individual and adjusted a diameter–age function. We recorded the presence of cones for each individual P. contorta within the plots and the total number of P. contorta individuals. In each plot, we measured percent vegetation cover (grass, understory and canopy). The selected parent stand showed a decrease in density from the original plantation spacing, from 2500 to 150 plants ha−1. Of all sampled individuals, only a 38% had cones. We found reproductive structures in trees as young as 5-year-old. Regeneration was found in all transects. Mean density for the area was 1600 plants ha−1, and the greater plant number was found in the West transect, reaching an average of 6600 plants ha−1. Through the interpolation performed with the kriging method, a map of the area with the spatial gradient of plant density was obtained. Naturally regenerated individuals of P. contorta occupied an area of 78 ha where the most distant individual is located in the southeast direction at an average distance of 1200 m from the three study plots. We determined that a positive association exists between P. contorta and the species A. araucana and Nothofagus antarctica. The capacity for early and consistent reproduction and the establishment of individuals dispersed at great distances from the original plots allow us to conclude that P. contorta has great potential as an invasive species in forests of this area of the Andes of southern South America. Invasion of P. contorta has many important implications for the conservation of native forests in our region including diminished regeneration of A. araucana.  相似文献   
57.
Various concentrations of culture filtrates from Fusarium subglutinans were tested for their effect on in vitro multiplication of plantlets and regeneration from calli of pineapple. The cultivars tested were the resistant Perolera and Spring and the susceptible Perola and Smooth Cayenne. The culture filtrate reduced shoot formation of in vitro plantlets and regeneration of plants from calli derived from the susceptible cultivars but plantlets and calli from resistant plants showed resistance. These results show the potential for culture filtrates of F. subglutinans to provide a method of in vitro screening of pineapple for resistance to the pathogen.  相似文献   
58.
Six ruminally cannulated steers (average BW = 791 ± 71 kg) were used in a replicated 3 × 3 Latin square experiment to determine the effects of roughage type on rumination, fiber mat characteristics, and rumen fermentation variables. Three roughages were included at 7% (DM basis) in a steam flaked corn-based diet: cotton burrs (CB), wheat silage (WS), or corn stalks (CS). Steers were fitted with a sensory collar to record rumination behaviors in 2-h intervals at the beginning of the experiment. Each 30-d period consisted of 7 d of recovery, 14 d of diet adaptation, 7 d of rumination data collection (daily and bi-hourly average rumination), 1 d of rumen fluid collection, and 1 d of rumen evacuations. In situ degradation of individual roughages was determined for 4 d after period 3 evacuations. During rumen evacuations, ruminal contents were removed; the rumen fiber mat (RF) was separated from the liquid portion with a 2-mm sieve, weighed, and a subsample was dried. Data were analyzed using the MIXED procedure of SAS with steer as the experimental unit and roughage (CB, WS, and CS) as the main effect. Dry matter intake (DMI) was not different for CB and WS (P = 0.25) and greatest for steers consuming CS diet (P ≤ 0.01). Roughage type did not influence the weight of the RF dry matter (%; DM; P = 0.92), RF weight (P = 0.69), or RF:DMI ratio (P = 0.29). Daily rumination (min/d) did not differ among roughages (P = 0.40), but min of rumination/kg of DMI was greatest for CS (18.0 min), min/kg of NDF was greatest for WS (89.8 min; P = 0.02), and min/kg of peNDF was greatest for CS (132.4 min; P ≤ 0.01). Wheat silage had the greatest percentage of soluble and degradable DM. Rumen fiber mat did not differ for roughages, although rumination min/kg of DMI and peNDF was greatest for steers consuming CS and WS. In situ degradation determined that CB-R and CS-R had the greatest percentage of ruminal undegraded DM. Based on the objective of the experiment, roughage type did not influence daily rumination or fiber mat characteristics.  相似文献   
59.
Four Babesia bigemina stabilates were used to determine the immune response of cattle to acute and chronic blood- and tick-borne infections. Thirty-two intact calves were divided into 16 groups of two and each calf was inoculated with infective B bigemina erythrocytic stabilates. Twenty-eight days later they were challanged with homologous and heterologous stabilates, and monitored for an additional 20 days. The hosts' apparently reduced response to homologous challenge but marked immune response to heterologous challenge indicated antigenic differences between the isolates and confirmed the conclusions reached by examination of the serological data.  相似文献   
60.
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