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121.
Universal primers to detect Satsuma dwarf virus (SDV), including distantly related strains Citrus mosaic virus (CiMV), Navel orange infectious mottling virus (NIMV), and Hyuganatsu virus (HV), were tested in a convenient one-step RT-PCR assay. SDV was the most broadly detected using uSDVup/uSDVdo primers that specifically targeted a nucleotide sequence in the 3′-noncoding region that is conserved in both segmented RNAs 1 and 2 of SDV among the tested primers. Nucleotide sequence analysis confirmed that the amplified RT-PCR products could be derived from RNAs 1 or 2 of SDV variants, some of which had interesting genetic diversity.  相似文献   
122.
Leptospirosis is a bacterial systemic infection which affects domestic animals and wildlife, as well as humans. Many wild animals act as reservoirs of leptospires. Nevertheless, the real role of wildlife animals as source of infection to livestock and humans, as well as the most important reservoirs and leptospiral strains remains unclear. This systematic review assesses the available data about wildlife and their biomes in Latin America, concerning to leptospiral infection. In addition, we discuss the development of the research on leptospirosis in wildlife in this region. After the application of exclusion criteria, 79 papers were analyzed, comprising 186 species, 122 genus, 53 families, and 19 orders from four classes. Mammals were the most studied class, followed by Amphibian, Reptile, and Aves. The Icterohaemorrhagiae serogroup was predominant in most biomes and many orders. A small number of antigens detected the majority of seroreactive animals of each class, and a smaller panel may be used at microscopic agglutination test. Further studies must always consider edaphoclimatic conditions besides only host class or species, in order to obtain a broader understanding of the wild epidemiological cycle of leptospirosis in the region. In conclusion, direct and indirect evidences demonstrate that leptospirosis is largely widespread among wildlife in all biomes of Latin America. Moreover, more research on the role of wildlife on the epidemiology of leptospirosis and its impact on livestock and public health are required, particularly focusing on direct detection of the agent.  相似文献   
123.
A randomized controlled trial (RCT) was carried to evaluate the effect of a feed additive on Campylobacter contamination of broilers reared in commercial conditions. Twenty‐four broiler flocks naturally contaminated with Campylobacter were enrolled in the RCT: 12 were assigned to a control group (C) fed with a conventional finishing feed from 4 weeks of age to slaughter (around 35 days), and the other group of 12 flocks (S) was fed with a finishing feed supplemented with 250 ppm of a patented feed additive (an ion‐exchanged clay compound) previously proven to reduce Campylobacter contamination in broiler caeca under experimental conditions. Enumeration of Campylobacter colonies in caeca (8 per flock) was carried out following ISO standards before feed distribution and at slaughter. Before treatment, the caecal Campylobacter load tended to be lower in C flocks (7.1 ± 1.9 log CFU/g, CI95% [6.6–7.5]) than in S flocks (7.7 ± 1.0 log UFC/g, CI95% [7.5–7.9]) (= .05). At slaughter, the bacterial load was similar in the S (7.7 ± 1.0 log CFU/g, CI95% [7.5–7.9]) and C groups (7.5 ± 1.2 log CFU/g, CI95% [7.2–7.8]) (= .73). Therefore, the feed additive had no significant effect on the caecal Campylobacter load at slaughter under the tested conditions. The logistical constraints inherent in field trials and the natural variability of Campylobacter contamination in naturally infected broiler flocks make it difficult to reproduce experimental results in in situ farm conditions. RCT testing of an intervention strategy in commercial situation is therefore a key step in evaluating pre‐harvest interventions against food‐borne pathogens.  相似文献   
124.
Summary This paper shows that the study of animal behaviour is a valuable aid to the improvement of the management of grazing livestock under extensive conditions. The food available to grazing animals in developing countries, and particularly in the dry season in the tropics, is often of very low quality and, in addition, is frequently available at low densities per unit area. Grazing ruminants attempt to adapt to these adverse conditions by increasing the time for which they graze each day and also by dispersing more widely. However, the time for which animals can graze may be limited by solar radiation and fly irritation in the day, and by the confining of the animals in pens at night. The adverse effects of the above limitations may be partially overcome when adapted local breeds are used. Dispersion of animals improves their ability to make use of extensive pasture and in order to encourage it, an understanding of the factors that affect it such as breed difference, social behaviour, adaptation and location of watering points and other unique environmental factors must be achieved. The paper concludes with recommendations of areas worth further research.
Effecto De Malas Condiciones Del Forraje Sobre El Comportamiento De Rumiantes En Pastoreo
Resumen Este articulo demuestra la importancia de estudiar el compartamiento de animales en pastoreo, para mejorar el manejo extensivo. El forraje disponible por unidad de superficie en países en vías de desarrollo es escaso y de mala calidad, sobre todo en época seca. Los rumiantes tratan de adaptarse a estas condiciones adversas incrementando el tiempo de pastoreo y dispersándose. Sin embargo el tiempo de pastoreo puede estar limitado por la radiación solar y la irritación causada por moscas durante el dia o porque los animales son encerrados durante la noche. Estos efectos pueden contrarrestarse utilizando razas criollas y bebederos estratégicamente localizados. Se requiere entonces más profundidad en estudios etológicos para incrementar la productividad de animales en pastoreo extensivo.

Effets De Mauvaises Conditions Fourrageres Sur Le Comportement De Ruminants Au Paturage
Résumé Cet article montre que l'étude du comportement animal est une aide appréciable pour l'amélioration de la conduite du bétail au pâturage en élevage extensif. La nourriture disponible pour les animaux au pâturage dans les pays en développement, particulièrement en saison sèche sous les tropiques, est souvent de très faible qualité et, de plus, fréquemment disponible en faible densité par unité de surface. Les ruminants essaient de s'adapter à ces mauvaises conditions en augmentant leur temps de pâturage chaque jour et aussi en se dispersant plus. Cependant, le temps de pâturage peut être limité par les rayons du soleil et l'irritation due aux mouches le jour, et par le confinement des animaux à l'enclos la nuit. Ces effets défavorables peuvent être partiellement surmontés par l'utilisation de races locales adaptées. La dispersion des animaux améliore leur possibilité d'utilisation des pâturages extensifs et pour favouriser cela, une compréhension des facteurs qui les affectent comme la différence de race, le comportement social, l'adaptation et la situation des points d'eau et d'autres facteurs du milieu doivent être considérés. L'auteur conclut en recommandant d'autres recherches valables pour ces régions.
  相似文献   
125.
Summary In an X-ray diffraction investigation, the recrystallization behavior of ball-milled Chinese southern pine wood was found to differ from that of cellulose. The crystallinity of lignocellulose milled for a very long time and recrystallized by wetting in water did not decrease with increasing milling time as was the case with milled cellulose. In addition, it appeared that the presence of lignin tended to restrict the amorphous cellulose produced by milling from recrystallizing into Cellulose II, whereas it had no influence on the recrystallization into Cellulose I. These results were discussed in the context of the mechanism of the conversion of Cellulose I to Cellulose II.  相似文献   
126.
We have recently expressed a new phytase enzyme in a yeast system. Three experiments with a total of 140 weanling crossbred pigs were conducted to examine the efficacy of this enzyme in improving the bioavailability of phytate-P in corn-soybean meal diets to young pigs. Experiment 1 compared the efficacy of this new phytase with a commercially available phytase (Natuphos, BASF) for 4 wk at an inclusion level of 1,200 U/kg of diet. Experiment 2 compared the responses of pigs to four doses of the new phytase supplementation (300, 600, 900, and 1,200 U/kg of diet) for 4 wk. Experiment 3 compared the efficacy of this new phytase and Natuphos at a marginally optimal dose (700 U/kg of diet) for 5 wk. A group of pigs were fed the P-deficient basal diet as a negative control in Exp. 1, and a group of pigs were fed the basal diet plus .17 or .22% inorganic P as a positive control in all experiments. In Exp. 1, pigs fed the two sources of phytase had similar ADG (564 vs 567 g), gain/feed (.597 vs .589), plasma inorganic P concentrations (8.9 vs 8.4 mg/dL), and mobility scores (4.25 vs 4.46) that were higher (P < .05) than those of the negative control. In Exp. 2, plasma inorganic P concentration was a fairly linear response to the phytase dose (r > .83) at wk 1 and 2. Overall ADG of pigs also tended to increase with the phytase dose (P = .15). In Exp. 3, pigs fed the two sources of phytase had ADG (483 vs 506 g) similar to that of the positive control (508 g). These two groups also had similar plasma inorganic P concentrations (7.7 vs 7.4 mg/dL) that were lower (P < .05) than those of the positive control group (9.7 mg/dL). There was no significant effect of dietary treatments on ADFI in all three experiments. In conclusion, our new phytase was as effective as Natuphos, at the inclusion level of 700 or 1,200 U/kg of a P-deficient, corn-soybean meal diet, in improving phytate-P utilization by young pigs.  相似文献   
127.
Protein concentrates (PCs) were extracted from three edible green seaweed species of Enteromorpha (E. compressa, E. linza, and E. tubulosa) and were studied for their functional properties with respect to salt and pH. The protein content in the PC was found to be 60.35 ± 2.0, 53.83 ± 0.70, and 33.36 ± 1.04% in E. compressa, E. tubulosa, and E. linza respectively. The minimum nitrogen solubility was observed at pH 4.0 in all three PCs. The water-holding and oil-holding capacities in the three PCs ranged from 1.22 ± 0.06 to 1.53 ± 0.07 ml H2O/g PC and from 1.05 ± 0.07 to 1.34 ± 0.10 ml oil/g PC respectively. Foaming capacity and stability were found to be pH-specific. They varied significantly with pH and NaCl concentration (P < 0.05). The inexpensive source of protein concentrate from Enteromorpha species could be incorporated into value-added food products.  相似文献   
128.
129.
Of 273 samples (rectal swab) collected from free-ranging yaks of Tawang district, Arunachal Pradesh, 42 Shiga toxin-producing Escherichia coli (STEC), six enteropathogenic E. coli (EPEC) and 27 enterotoxigenic E. coli (ETEC) strains were isolated. All the STEC and EPEC strains were further investigated for respective stx variants (for STEC only) and additional putative virulence factors. The 27 ETEC strains were also screened for characteristic enterotoxin gene(s) and colonization factors. Occurrence of ETEC was significantly (p < 0.05) higher in the diarrheic yaks and yaks of less than 1 year of age. Majority of enterovirulent E. coli isolates were resistant to amikacin, azithromycin, chloramphenicol, colistin, doxycycline, furazolidone, nalidixic acid, nitrofurantoin, streptomycin and tetracycline. Dendrogram, constructed with molecular fingerprinting profiles obtained from RAPD (Randomly Amplified Polymorphic DNA) and ERIC (Enterobacterial Repetitive Intergenic Consensus) PCR, placed the isolates in different clusters irrespective of their serotypes, virulence gene and drug resistance pattern. Collectively, the study indicates that yaks, being a potential reservoir of multidrug resistant STEC and EPEC, may represent significant risk to public health in this region. Higher recovery of ETEC isolates from yaks with diarrhea points out that ETEC may be a major determinant for repeated occurrence of diarrhea in yaks.  相似文献   
130.
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