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991.
992.
A cross-sectional study was conducted at two large abattoirs in the winter 2003/04 to determine the prevalence of gastric lesions in Swiss finishing pigs. The stomachs of 1897 pigs from 107 slaughter groups were examined for macroscopic epithelial lesion of the pars proventricularis. Severe hyperceratosis, erosion, ulceration and constriction at the transition between oesophagus and stomach were described as gastric lesions. Lesions were observed in 36% of all animals, with slaughter group prevalence ranging from 0% to 94%. Ulceration or constriction was present in four percent of the examined pigs. Associations between gastric lesions, farm management data, and data obtained at ante and post mortem examinations conducted at the slaughterhouse were analysed. A significantly higher prevalence of gastric lesions was found in pigs originating from conventional housing systems compared to pigs raised on farms with 'animal-friendly' housing systems providing straw bedding and outdoor exercise to pigs. In addition, significantly higher prevalence was observed in pigs originating from herds with clinical signs of tail biting and peritarsitis. 相似文献
993.
The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are a new chemical class of herbicide which possess the same antimicrotubule mechanism of action as dinitroanilines, probably including interaction with the same binding site in alpha-tubulin. 相似文献
994.
Landscape-scale Edge Effect in Predation Risk in Forest-farmland Mosaics of Central Europe 总被引:8,自引:1,他引:7
Avian nest predation is known to increase with the degree of forest fragmentation. A common explanation is that farmland allows
for high densities of generalist predators, and predators penetrating into the forest cause higher nest losses at forest-farmland
edges than in forest interiors. In contrast to numerous patch-level studies of forest edge effects conducted earlier, we broadened
the spatial extent to the landscape. We tested the hypothesis of increased predation near farmland over distances of >4 km
from forest–farmland edges into forest interiors in five mountain ranges in Germany, using artificial ground nests. We considered
two landscape settings: (1) Transitions between a forest matrix and a farmland matrix, and (2) farmland patches within a forest
matrix. Nest losses were not significantly higher in vicinity to a farmland matrix, but proximity to a pasture within the
forest matrix strongly increased predation risk. We speculate that these differences resulted from landscape geometry. Farmland
patches and matrix alike are highly attractive to generalist predators, and are regularly visited by red foxes from the forest.
Predators that traverse the forest and take prey along the way, will cause a concentration of predation risk towards a patch
(pasture), but not towards an adjacent matrix (farming lowlands), of feeding habitat. Contrary to previous evidence that edge
effects in nest predation level off after 50 m, nest fate was related to distance to pastures across the entire study extent
of 4.1 km. Our results suggest that landscape context and predator mobility may greatly affect spatial predation patterns. 相似文献
995.
996.
997.
A Bréard 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1990,43(4):457-458
A synthetic serum substitute (Basal Medium Supplementation, BMS), has been utilized for growing mycoplasmas. Over agar medium, colonies become atypical. In liquid medium, microscope examination only reveals coccoidal elements, and their growth is inferior in amount to that obtained with a traditional animal serum. After the tenth subculture, the bacteria recover their full characteristics when submitted to a passage on a traditional medium. Due to its known composition, this synthetic serum substitute should be usable for advanced studies of mycoplasma organisms, in molecular biology for instance, but its use for isolating strains or antigen production is not recommended. 相似文献
998.
B Lampe F Schneider K P Brüssow G Bl?dow K Wollenhaupt K Spitschak U Hühn 《Archiv fuer experimentelle veterinaermedizin》1990,44(3):347-356
Experimental studies were conducted into ovariectomized pregnant gilts to establish effects of exogenic hormone administration, with endogenic ovarian steroids excluded, upon uterus and fetus development as well as on hormone levels in blood plasma, endometrium, and allantoic fluid. Hormone concentrations in blood plasma were found to depend clearly on hormone doses applied after ovariectomy to preserve pregnancy. 2 to 3 weeks of smooth gravidity, following ovariectomy, were ensured on the 6th or 14th day after KB1 by daily application of very low doses of progesterone only (80 mg) or in combination with estrogens, the ratio being 480:1. 相似文献
999.
Brígido C da Fonseca IP Parreira R Fazendeiro I do Rosário VE Centeno-Lima S 《Veterinary parasitology》2004,123(1-2):17-23
A survey was conducted during the months of April-June 2003 in the northeast Portugal (Bragan?a district) in order to characterize the hemoparasite population of an autochthonous Mirandesa breed of Bos taurus. The polymerase chain reaction (PCR) analysis of the bovine blood revealed that 3 out of 116 animals were infected with Theileria and/or Babesia parasites, while reverse line blot hybridisation (RLB) analysis showed that these animals were infected with Theileria buffeli/orientalis. Cloning and sequencing confirmed the RLB results. Database sequence searches combined with phylogenetic analysis of the partial 18S ribosomal RNA gene sequences obtained enabled us to place the parasites in question as members of the T. buffeli/orientalis group, confirming the PCR/RLB diagnosis. 相似文献
1000.
González-Rey C Svenson SB Bravo L Siitonen A Pasquale V Dumontet S Ciznar I Krovacek K 《Comparative immunology, microbiology and infectious diseases》2004,27(2):129-139
A total of 73 strains of Plesiomonas shigelloides isolated from humans (24 strains) animals (21 strains) and aquatic environment (28 strains) were determined for their O:H serotype and susceptibility to 18 anti-microbial substances and to the vibriostatic agent O/129. Of all strains, 86.3% were typeable by the O and 94.5% by the H anti-sera used. The serotype distribution was heterogeneous within a country and between the countries. Of the 57 different serotypes identified, O11:H2 (2 strains), O22:H3 (4 strains), O35:HH11 (2 strains), O52:H3 (2 strains) and O90:H6 (2 strains) were found among isolates from humans and animals (mainly in cats) in Finland and Cuba, and O23:H1a1b (3 strains) among isolates from environmental sources in Slovak Republic and Italy. Most (93-100%) of all strains were susceptible to all anti-microbials tested but resistant (92-96%) to the broad-spectrum penicillins (ampicillin, mezlocillin). No correlation between anti-microbial resistance patterns and serotypes was found. 相似文献