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81.
A new insect order, Mantophasmatodea, is described on the basis of museum specimens of a new genus with two species: Mantophasma zephyra gen. et sp. nov. (one female from Namibia) and M. subsolana sp. nov. (one male from Tanzania). This is the first time since 1914 that a newly described extant insect taxon has proved unplaceable within a recognized order. Mantophasmatodeans are apterous carnivores. Their closest phylogenetic relationships may be to Grylloblattodea (ice-crawlers) and/or Phasmatodea (stick insects), but the morphological evidence is ambiguous. Raptophasma Zompro from Baltic amber is assigned to the Mantophasmatodea, revealing a wider previous range for the lineage.  相似文献   
82.
Primary cilia (PC) were demonstrated for the first time in fish endothelial, epithelial and fibroblast cell lines through immunofluorescence staining with the monoclonal antibody, 6-11B-1, against acetylated α-tubulin. The study was carried out with eight recently developed cell lines from the walleye, Sander vitreus (Mitchill). These were three fibroblast-like cell lines, WE-cfin11f, WE-skin11f and WE-liver3 from, respectively, the caudal fin, skin and liver, and three epithelial-like cell lines, WE-cfin11e, WE-spleen6 and WErpe from, respectively, the caudal fin, spleen and retina. Also, endothelial-like WEBA from the bulbus arteriosus and glial-like WE-brain5 from the brain were used. Immunocytochemistry revealed strong staining for acetylated α-tubulin in mitotic spindles and midbodies for all cell lines, and in PC for all cell lines except WE-skin11f. Staining of cytoplasmic microtubules (fibrils) was absent in three cell lines, including WEBA, but present in the others, especially WE-skin11f, which might have obscured PC detection in these cells. Tubacin, an inhibitor of histone deacetylase 6, induced cytoplasmic fibrils in WEBA and the intensity of their staining in WE-cfin11f. These results suggest that the cell lines might differ in their deacetylase activities, making them useful for studying this tubulin modification in teleosts, as well as for studying PC.  相似文献   
83.
Different measures of capacity and capacity utilization (CU) are estimated and examined for the multi-species Danish Gill-net fleet using a mathematical programming approach—data envelopment analysis (DEA). The potential capacity output is calculated using an output-orientated measure. CU is assessed using both a partial CU measure, which permits CU to be assessed relative to each output, and a ray measure. Based on the ray measure, the average CU for the Danish Gill-net fleet was estimated to be between 0.85 and 0.95. The partial CU measure for cod was determined to be approximately the same as the overall or ray CU measure, but the partial CU measure for plaice was less than the level of the ray measure, which indicated that the production of plaice could be increased by a higher proportion than could the production of cod. The optimal variable input utilization was also estimated. It was determined that, on average, the variable input—number of trips—could be increased by 27% compared to the optimal level. Results also indicated higher excess capacity for cod and sole than for other species, which is in accordance with how the fishery developed.  相似文献   
84.
Water exchange, flow patterns and deposition of sediment and phosphorus were measured in cross-sections of a naturally functioning floodplain during one winter and in three restored floodplains following remeandering of formerly straightened and channelized rivers. Sediment and phosphorus depositional processes were studied, deploying artificial grass mats at different distances from the river channel. In addition, a mass-balance approach was applied on the experimental site. Our results show that the deposition of sediment and particulate phosphorus constituted 3,000–4,700 g DW m?2 and 1.2–7.3 g P m?2, respectively, on the four floodplains studied during a winter where flood duration lasted between 20 and 76 days. The storage efficiency for sediment ranged between 28–47 and 4.0–7.0% for phosphorus.  相似文献   
85.
A dual column photobioreactor (PBR) (2 × 47 L) with mixed CO2/air bubbling was tested for cultivation of the microalga Rhodomonas salina as food for live feed copepods. In the continuous growth phase, the cell density was relatively stable at 2.40 ± 0.13 × 106 cells/ml at an average dilution rate of 0.46 ± 0.02 per day throughout the 30‐day experiment. The produced algae had a high content of both total fatty acids (TFA) and free amino acids (FAA). Especially, the harvested algae contained a high proportion of poly‐unsaturated fatty acids that made up 80% of the TFA and of essential amino acids (35% of all FAA), implicating desirable components as feed for copepods. The current PBR was sufficient to feed a culture of the calanoid copepod Acartia tonsa at a density of 2,500 adult/L in ca. 500 L culture with a daily yield of approximately 17 × 106 eggs. To be able to sustain the integrated copepods production, the suggested volume of the algae cultures should be ca. 20% of the copepod culture volume.  相似文献   
86.
Mayer  Martin  Ullmann  Wiebke  Heinrich  Rebecca  Fischer  Christina  Blaum  Niels  Sunde  Peter 《Landscape Ecology》2019,34(10):2279-2294
Landscape Ecology - Human land use intensified over the last century and simultaneously, extreme weather events have become more frequent. However, little is known about the interplay between...  相似文献   
87.
The normal habitat of the parasitic stages of Ascaridia galli is in the small intestine of poultry but the exact localization is poorly understood. Therefore, a histological study was conducted in order to localize the larvae during the early phase of infection. Six layer pullets seven-week old were infected orally with 20,000 embryonated A. galli eggs each, whereas four chickens were left as un-infected controls. At necropsy 3 days after infection the first half of jejunum/ileum was divided into two equally sized sections (J1 and J2). After taking samples for histology from the middle of J1 and J2 and the junction between these determined JX, the two sections were subjected to parasitological examination. A higher number of A. galli larvae were recovered from section J2 than J1 and the majority of larvae were recovered from the most profound layers. Based on histology 144 larvae were identified and their location was noted. The highest number of larvae was observed in the JX sample as compared to J1 and J2 (P<0.001). Most of them were located in the profound crypt zone of the mucosa (51%) as compared to the other zones (P<0.05). The number of larvae was higher in the lumen (63%) compared to the epithelium (32%) and lamina propria (5%) (P<0.001). A significantly higher number of eosinophils were found in lamina propria of the infected group compared to the control group (P<0.001). This experiment clearly showed that only few larvae had penetrated the epithelium and were positioned in the lamina propria at 3 days post infection. It was far more common that the larvae were localized within the epithelium or in the lumen of the crypts. It is therefore suggested that at least in this early phase "mucosal phase" is a more appropriate term to be used for the A. galli larval localization as compared to the term "histotrophic phase" currently used in many textbooks.  相似文献   
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90.
A novel indirect ELISA test using deoxycholate extracted antigens coated onto a hydrophobic polystyrene surface for measurement of serum antibodies specific for Mycoplasma hyosynoviae was developed. Sensitivity and specificity of the test were found to be superior to previous ELISAs as tested on porcine serum following experimental Mycoplasma infections as well as by analysis of samples from one Danish herd known to be free of M. hyosynoviae and samples from two Norwegian herds without clinical suspicion of M. hyosynoviae infections since their establishment. The epidemiology of M. hyosynoviae infection was then investigated in Danish pig herds with evidence of clinical M. hyosynoviae arthritis (MhA herds, n = 4) and in herds with M. hyosynoviae-carriers among slaughter pigs, but with limited clinical lameness (MhC herds, n = 4). M. hyosynoviae bacteriaemia and tonsil-carrier state were determined by culture of cross-sectional samples of whole-blood (n = 238) and tonsil scrapings (n = 322), respectively. Levels of serum antibodies (n = 396) were measured by the novel indirect ELISA test. There was no significant difference in the ELISA results between the MhA and the MhC herds. Pigs that were tonsil-carriers had a significantly higher response in the ELISA test (P < 0.001) than non-carriers. Slaughter pigs showed higher ELISA values (P < 0.001) and they were more prone to be tonsil-carriers (P < 0.001). The most critical period for spread of the infection seems to be the nursery period (4-12 weeks). The results indicate that M. hyosynoviae infection progresses similarly in herds irrespective of the presence of clinical arthritis. Thus, clinical arthritis due to M. hyosynoviae is probably triggered by other host or herd factors than low levels of serum antibodies or by differences in virulence factors between M. hyosynoviae strains.  相似文献   
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