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131.
The characterization of indigenous animal genetic resources is a requisite step in providing needed information for the conservation of useful genotypes against future needs. Thus, in this study, 22 microsatellite markers were used to genotype 114 local chickens from the Forest (n = 59) and Savannah (n = 55) eco‐zones of Ghana and the results compared to those of the ancestral red junglefowl (n = 15) and two European commercial chicken populations – a broiler (n = 25) and white leghorn (n = 25). A total of 171 alleles were observed, with an average of 7.8 alleles per locus. The local Ghanaian chickens showed higher diversity in terms of the observed number of alleles per locus (6.6) and observed heterozygosity (0.568) compared with the combined control populations (6.0 and 0.458, respectively). However, Wright's F‐statistics revealed negligible genetic differentiation (FST) in local Ghanaian chicken populations. In addition, 65% of the Savannah chickens were inferred to be more likely from the Forest, suggesting a south‐north dispersal of chickens from their probable original location in the Forest zone to the Savannah areas. It is concluded that the Forest and Savannah chickens of Ghana are a single, randomly mating unselected population, characterized by high genetic diversity and constitute a valuable resource for conservation and improvement.  相似文献   
132.
An 8-year-old intact female Huacaya alpaca (Lama pacos) was presented for recent development of male behavior. Serum testosterone concentration was determined to be 969.1 pg/ml by using radioimmunoassay, while the range in 33 healthy female adult intact alpacas was 11.7-62.1 pg/ml. An ovarian mass was suspected, and an exploratory laparotomy was performed. A tan mass was present on the left ovary. Histologically, the mass was composed of closely packed, plump, polygonal cells with central round nuclei with granular chromatin and abundant eosinophilic finely granular to vesiculate cytoplasm. An ovarian benign interstitial (Leydig) cell tumor was diagnosed.  相似文献   
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134.
Valentine  J. 《Euphytica》1984,33(3):943-951
Summary Accelerated pedigree selection (APS) involves initial selection based on the assessment of lines rather than individual plants. These lines can be derived by accelerated generation procedures. Unlike single seed descent (SSD), line selection can begin in an early generation. This minimises the risk of differential mortality or sterility. Brief outlines of APS for spring and winter cereals are given. The length of the APS breeding cycle is shorter than that of either pedigree selection (PS) or SSD. In addition to higher efficiency of selection for yield, which must be offset against the need for greater resources, it is expected that APS should result in valuable genotypes being retained and better selection for desirable combinations of characters.  相似文献   
135.
Soil degradation limits the potential for the re‐establishment of native plants. Most land restoration practices typically concentrate on the recovery of soil physical properties and plant establishment, while neglecting the recovery of soil microbiota. Mediterranean wild leguminous shrubs are ideal candidates for use in land recovery projects, as they are drought tolerant, improve soil fertility through biological nitrogen fixation and exhibit high stem net photosynthesis that increases their carbon gain. In this study, we used the legumes Cytisus balansae, Cytisus multiflorus, Cytisus striatus and Genista florida in a long‐term trial to recover a degraded soil in southwestern Spain. The main objective of this trial was to investigate to what extent the introduction of shrubby legumes inoculated with their own rhizobial symbionts can improve the properties and associated vegetation of a degraded soil. The results showed that the inoculation of legumes with nitrogen‐fixing bacteria enhanced plant performance in all four legumes. Whereas in the absence of legumes, soil fertility and plant community did not improve significantly, amelioration was observed in plots with non‐inoculated legumes, with maximum values in terms of the number of accompanying species, soil nitrogen content and organic matter recorded in soils with inoculated legumes. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
136.
One challenge in predictive modelling of productivity for pastures varying in topography, soils or management is to achieve the prediction over space with acceptable accuracy. As a new modelling approach, the decision tree has been shown to have high predictive accuracy; while geographical information systems (GISs), with their strong ability to deal with spatial factors, have been widely used in environmental modelling. Integration of a decision tree approach with a GIS offers a potential solution in meeting this challenge. In this study, decision tree models were developed for annual and seasonal pasture productivity (aboveground dry matter in kg/ha) using environmental and management variables and the outputs of these decision trees were integrated with a GIS to get predictions of pasture productivity in a hill-pasture grazing system. Results showed that the decision tree model for annual pasture productivity adequately predicted 91% of cases in the model validation, and the GIS-based prediction for annual pasture productivity was verified in three of four test farmlets. The decision tree models also revealed the relative importance of environmental and management variables and their interaction in influencing pasture productivity. Hill slope, soil Olsen P and annual P fertiliser input were the most significant variables influencing annual pasture productivity, while hill slope, annual P fertiliser input, autumn rainfall and soil Olsen P were the most significant variables influencing spring, summer, autumn and winter pasture productivity, respectively. The successful integration of the decision tree model with a GIS in this study provided a platform to predict pasture productivity for pastures with heterogeneous environmental variables and management features, and to present model predictions over space for further application and investigation. This modelling approach can be used as, or incorporated in, decision support systems to improve pasture management, and to investigate the interrelationship between pasture productivity and environmental and management variables.  相似文献   
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138.
Intramuscular desmoid tumors (musculoaponeurotic fibromatosis) were discovered in two young adult horses. The tumor in one horse was in the lateral cervical musculature, and that in the second horse occurred in the pectoral musculature. Histopathologic features were similar in both horses and included proliferation of fibroblasts and cells expressing muscle actin (myofibroblasts), with extensive dissecting fibrosis within muscle. These features are similar to those of desmoid tumors in humans, particularly those also known as musculoaponeurotic fibromatosis. Dissection of these lesions revealed a single central (horse No. 1) or multiple central (horse No. 2) fluid-filled cavities with associated sterile inflammation. The presence of these cavities supports the hypothesis that equine desmoid tumors are traumatic in origin, possibly occurring at sites of injections or bursal rupture. Surgical excision of the tumor in horse No. 1 was apparently curative, but the extent of the tumor in horse No. 2 precluded surgical excision.  相似文献   
139.
The clinical and clinicopathological characteristics, treatment and outcome of vermicular muscle contractions (myokymia) and generalized muscle stiffness (neuromyotonia) in 37 Jack Russell terriers were evaluated retrospectively. Thirty dogs were affected by both disorders, whereas seven were presented with myokymia and never developed neuromyotonia. Clinical signs started at the mean age of 8 months. Except for signs of myokymia and neuromyotonia, clinical and neurological examination was normal in all dogs. Thirty dogs demonstrated typical signs of hereditary ataxia.Changes in serum chemistry included increased creatine kinase, aspartate aminotransferase and alanine aminotransferase concentrations. Electromyographic abnormalities, especially in muscles showing macroscopically visible myokymia, consisted of semirhythmic bursts of doublet, triplet, or multiplet discharges of a single motor unit. The amplitudes varied between 80 μV and 1 mV and occurred with an interburst frequency between 10 and 40 Hz and an intraburst frequency between 150 and 280 Hz.Most dogs were treated with a sodium channel blocker with variable results. Seven dogs died (most likely because of hyperthermia) or were euthanased during a neuromyotonic attack; 15 dogs were euthanased due to worsening of clinical signs, or lack of or no long-lasting effect of medication, and three were euthanased for unknown or unrelated reasons. Nine dogs were lost to follow-up and three were still alive 5–10.5 years after the start of clinical signs. In conclusion, young Jack Russell terriers with myokymia and neuromyotonia should undergo a complete blood and electrophysiological examination. Long-term prognosis is not favourable.  相似文献   
140.
“Fonio” (Digitaria exilis (L.) Stapf.) is a member of the grass family with excellent culinary and nutritional properties. In spite of its economic values, hardly has any improvement work been done. To enhance genetic improvement of this grain, plant regeneration protocol was developed using 8 cultivars. Stem segments of 5 mm long excised from 1 month-old seedlings germinated in vitro were cultured on 6 types of media for friable callus induction. Best result was obtained on Murashige and Skoog (MS) medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 g l−1 casamino acid, where 91.3, 88.9 and 87.8% of the explants formed friable calli in cultivars ‘Kurelep’, ‘Churiwe’ and ‘Agyong’, respectively. Shoots appeared when friable calli were transferred to two regeneration media, i.e., MSBZ (MS medium + 0.022 mg l−1 2,4-D, 0 .22 mg l−1 6-benzylaminopurine (BA), 0.22 mg l−1 zeatin) and MSBG (MS medium + 0.5 mg l−1 BA, 0.1 mg l−1 gibberellic acid). The highest frequency of plant regeneration was attained on MSBG, with 91.7% of the friable calli forming shoots in cultivar “Churiwe”. Regenerated plants were rooted on hormone free MS medium. Flow cytometric analysis revealed 100% of the regenerants to be diploid. The protocol developed here can be used in the transformation of “Fonio” to increase the yield potential of this crop by incorporating characteristics such as disease resistance and stress resistance.  相似文献   
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