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31.
A model was developed to classify the Italian territories in relation to their suitability to harbour populations of Culicoides imicola and, as a consequence, also able to sustain a bluetongue (BT) epidemic. Italy was subdivided into 3507 10 x 10 km cells. In 546 cells at least one collection was made. The cell was considered the unit for all subsequent analyses. Culicoides were collected using Onderstepoort-type blacklight traps. Some traps were operated weekly at chosen sites; the remainder were moved almost daily to new sites. Only the results obtained during the peak August-November period were used, to exclude bias caused by the seasonality of C. imicola. Climate data for the period 1999-2001 were obtained from 80 weather stations. Multiple logistic regression was performed using the presence or absence of C. imicola in a specific cell as the dependent variable. Annual means of daily values for minimum temperature and minimum relative humidity, and the mean altitude above sea level, were the independent variables. The probability of occurrence of C. imicola in each grid cell was used to create a prediction map for Italy. The model was able to correctly classify 77.5% of the 546 grid cells in which at least one collection had been made. Culicoides imicola was found frequently through much of Sardinia, in parts of southern Italy, and further north along the Tyrrhenian coast, but was absent from along most of the Adriatic coast, and the internal mainland, and from most of Sicily. Six detailed maps are provided. Also mapped are areas where the probability of the occurrence of C. imicola is lower than 5%. This identification of possible mountainous C. imicola-free areas in central Italy could facilitate safer animal trade and transhumance, even if BT infections in traded animals or moving stock, were to go undetected. Needless to say this depends upon no cool-adapted species of Culicoides being involved in the transmission of BT disease.  相似文献   
32.
During final phases of eradication programmes, strains of Mycobacterium sp. not belonging to the tuberculosis complex increase their relative frequency and are responsible for positive skin test reactions. Moreover, the specificity of any indirect diagnostic test, such as the skin test, is never completely accurate, therefore even when tuberculosis infection is completely eradicated, a number of false positive reactions are to be expected. The aim of this paper is to evaluate the performances of traditional isolation/typing techniques, automatic isolation/typing techniques based on fluorimetric detection of bacterial growth (Bactec), skin tests and the -interferon test. Samples examined for the evaluation of test sensitivities originated from 154 infected animals belonging to 32 infected herds. Samples used as negative controls in the evaluation of test specificities originated from 86 animals of nine officially infection-free herds. The automatic isolation/typing technique based on fluorimetric detection of bacterial growth showed higher sensitivity than the traditional isolation typing technique. Moreover, it allowed a safer processing of bacterial cultures, decreasing the risk for laboratory workers. The observed performance of the gamma-interferon test was considered beneficial in that it increased the sensitivity of individual diagnosis within an infected herd, especially in 'problem herds', but its poor specificity did not improve detection of infected herds compared to the skin test.  相似文献   
33.
Ultrastructural details of the hypersensitive reaction induced by infiltration with avirulent race 2 Xanthomonas campestris pv. vesicatoria in pepper Early Calwonder-10R leaves (incompatible interaction) are reported. Affected cells displayed plasmalemma undulations and disruption, lysis of the chloroplast membrane, degeneration of other organelles, general cytoplasm disorganisation and, often, protoplast shrinkage. The nuclei contained large masses of electron-dense material, apparently formed by chromatin aggregation. In many cases a single chromatin-like layer was deposited on the inner side of the nuclear envelope leaving a finely granular matrix in the centre of the nucleus; the nucleolus usually disappeared. The nuclear envelope was sometimes ruptured and the internal matrix leaked into the cytoplasm. The content of many affected cells eventually coagulated and became very electron-dense. The walls often collapsed. All these alterations were especially visible in spongy mesophyll cells at sites where bacteria occurred in the intercellular spaces. Although some of the nuclear and cytoplasmic alterations recall certain aspects of apoptotic cell death, molecular determinations did not reveal any DNA degradation in hypersensitively reacting tissues. The first cell alterations in leaves infected with the virulent bacterial race 1 (compatible interaction) were observed only 27h after inoculation, when the cytoplasm of some cells showed limited internal disorganisation and plasmolysis at sites where bacterial colonies developed.  相似文献   
34.
The ten largest food and beveragecorporations control over half of the food sales inthe United States and their share may be increasing.Using data from a range of secondary sources, weexamine these corporations and their boards ofdirectors. Social and demographic characteristics ofboard members gleaned from corporate reports, thebusiness press, and elsewhere are presented.Information on interlocking corporate directorates andother common ties among members of the boards ofdirectors show that US based food and beveragecorporations are tied together through a web ofindirect interlocks.  相似文献   
35.
36.
Anthocyanins (Anths) in olive (Olea europaea L.) fruits at different degrees of pigmentation were assessed nondestructively by measuring chlorophyll fluorescence (ChlF). The method is based on the comparison of the ChlF excitation spectra from olives with different pigmentation from green to green-red, reddish-purple, and purple. The logarithm of the ratio between the fluorescence excitation spectra (logFER) from two different colored zones gave the difference in the absorption spectrum between them. The absorbance spectrum derived from the logFER between a red olive and the same olive devoid of the skin showed the typical Anth green band (at 550 nm). It matched that recorded by microspectrophotometry on a single pulp cell and the in vitro absorbance spectrum of the olive skin extract. As expected, the in vivo Anths absorption maximum increased in intensity going from less to more mature olives and was higher in the sun-exposed olive side with respect to the sun-shaded side. Absolute quantitative nondestructive determination of Anths for each olive sample was obtained by the logFER calculated for two excitation wavelengths, 550 and 625 nm, of ChlF at 740 nm. Going from green to purple skin colors, the Log[ChlF(625)/ChlF(550)] was fairly well-correlated to the extract Anths concentration. Finally, the relationship between the Anths and the other main phenolics present in the olives analyzed by high-performance liquid chromatography was evaluated. The main result was a net increase of verbascoside with increasing Anths content. On the basis of our results, the development of a new rapid and noninvasive method for the monitoring of olive development and ripening can be envisaged.  相似文献   
37.
  1. The conservation of marine megafauna presents numerous difficulties owing to their high mobility over difficult-to-access oceanic areas that impairs the collection of basic, but essential, biological information.
  2. The Bryde's whale (Balaenoptera edeni) is one of the most elusive species of baleen whales, and although it is known to be a seasonal visitor to several archipelagos in Macaronesia (the Azores, Madeira, and Canaries), there are no studies regarding its occurrence or geographical connectivity in this area of the Atlantic.
  3. A 14-year photographic database was used to determine short-term (intra-seasonal) and long-term (inter-annual) Bryde's whale site fidelity and to estimate individual residency times in Madeira, whereas photographic catalogues from Madeira and the Canaries were compared in order to assess large-scale movements (i.e. on the scale of hundreds of kilometres).
  4. In Madeira, 59 individuals were identified, 27 (45.8%) of which were recaptured. Of these, 10 individuals (37.0%) presented short-term site fidelity and 17 individuals (63.0%) presented long-term site fidelity, with a maximum recapture interval of 12 years. Lagged identification rates showed that five individuals (SE = 2) remained in the area for 32 days (SE = 108 days) before leaving and not returning during the same year. Seven individuals were seen both in Madeira and the Canaries (catalogue comprising 51 individuals), three of which were identified multiple times in both archipelagos, with a minimum of 43 days between consecutive sightings.
  5. This information combined with the fact that this species is commonly sighted accompanied by calves and feeding in both archipelagos highlights the ecological importance of this area for Bryde's whales. This should be taken into consideration by policymakers when implementing conservation measures, where coordination of effort among countries is needed. This study also reinforces the value of using data from platforms of opportunity and of making photographic data open access.
  相似文献   
38.
Journal of Pest Science - The invasive stink bug Halyomorpha halys, native to East Asia, is a severe agricultural pest of worldwide importance, and chemical insecticides are largely sprayed for its...  相似文献   
39.
The role of flow rate on Cd transport through a natural aquifer sand was investigated using a laboratory column set-up with particular reference to dissolution processes of external coatings. Clays and (hydr)oxides dissolution was investigated by tests performed feeding the column with Cd-free solutions at three different flow rates (0.2, 1 and 5 mL min–1). Flow rate significantly affected only the dissolution of Fe-containing coatings by releasing into the liquid phase different amounts of Fe. Cd transport experiments showed a strong effect of flow rate on Cd breakthrough curves and the lowest Cd adsorption was observed at the lowest flow rate. This behavior was fully explained in terms of competition between dissolved Fe and applied Cd for the same adsorption sites. Comparison of the Cd transport behavior on a pure quartz sand allowed confirmation of the strong influence of clay and (hydro)oxide coatings in determining the surface properties of the heterogeneous natural materials. An equilibrium model was proposed to describe the dynamic Cd behavior under the different experimental conditions (flow rates and Cd concentrations).  相似文献   
40.
Roots, cotyledons, leaves, stems, pods, and seeds of three soy cultivars were analyzed for their content of isoflavones, flavonols, coumarins, and phenolic acid derivatives with three samplings during a three-month period. The extracts were analyzed by HPLC/DAD and HPLC/MS, allowing us to confirm the presence of daidzein and genistein derivatives as the major isoflavones and to characterize coumarins, most flavonols and phenolic acid derivatives. Seeds exhibited the highest content of isoflavones: 12.61 g/kg of dry weight (DW) in cv. Emiliana; 8.97 g/kg of DW in cv. Elvir; 4.49 g/kg of DW in cv. Kure, and roots are the only part with coumarins, ranging from 4.08 g/kg of DW (cv. Emiliana) to 1.29 g/kg of DW (cv. Elvir) for the longest sampling period. Leaves, pods, and stems have flavonols, and in particular leaves showed: 7.28 g/kg of DW in cv. Emiliana; 6.57 g/kg of DW in cv. Elvir; 7.08 g/kg of DW in cv. Kure. The high content of isoflavones found in the seeds could be ascribed to the natural conditions under which the soy plants were grown.  相似文献   
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