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411.
The clinical, haematological and biochemical findings, treatment and outcome of 63 cows with haemorrhagic bowel syndrome are described. The general condition and demeanor were moderately to severely abnormal in all the cows. Signs of colic occurred in 27 cows, decreased rectal temperature in 46 and tachycardia in 44. With the exception of one cow, intestinal motility was decreased or absent. Transrectal palpation revealed dilatation of the rumen in 47 cows and dilatation of the small intestine in 18. Faecal output was markedly reduced or absent, and the faeces were dark brown to black and contained blood. Nine cows were euthanized immediately after physical examination. Conservative medical therapy was instituted in two cows; however, both were euthanized a few days later because of deterioration in condition. Exploratory right flank laparotomy was carried out in 52 cows. Of these, 22 were euthanized intraoperatively because of severe lesions. In 27 cows, intestinal massage to reduce the size of blood clots was carried out; 11 were euthanized several days postoperatively because of deterioration in condition. In three other cows, intestinal resection was carried out and all survived. Of the 63 cows, 19 (30.2%) survived and were healthy at the time of discharge from the clinic.  相似文献   
412.
We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionally used and frequently used area on the basis of the intensity of the picnic activities. A total of 43 plant species were enumerated in the whole study area. The highest plant species richness (41 species) was observed in the non-used area whereas the lowest species richness (11 species) in the frequently used area. The diversity index decreased with the increase of picnic intensity whereas the concentration of dominance increased. Density of all plant groups except mature trees, and the basal area of the mature trees showed a declining trend from the non-used to frequently used area. The frequently used area exhibited very poor regeneration. Tree vitality decreased with the increase of picnic intensity. The relevance of our study as a basis for further research to determine the impact of tourism on biodiversity in Bangladesh is discussed.  相似文献   
413.
The drug sensitivities of 16 Trypanosoma evansi isolates from Sudan were examined using two different in vitro assays and rodent models. IC50 values (concentration which inhibited incorporation of 3H-hypoxanthine by 50%) obtained in a 40 h assay indicate that most of the isolates were resistant to suramin, a drug which has not been used in Sudan since 1975. Sensitivities for suramin in a 10-day-in vitro assay varied within a 124-fold range. The in vitro results were confirmed by infection/treatment experiments in mice. Sensitivities in vitro for quinapyramine varied within a 166-fold range. In mice, the least sensitive isolates were not cured with dosages up to 10 mg/kg quinapyramine. Based on in vitro results, all isolates appeared to be susceptible to isometamidium.  相似文献   
414.
The objective of the investigation was to identify the most important organic N-containing fractions extracted from soils by electroultrafiltration (EUF) or a CaCl2 solution, respectively, and their importance for nitrogen mineralization. The investigation comprised 19 agricultural and one forest top soil. Net N mineralization was tested in Mitscherlich pot experiments with three treatments: (1) fallow soil without N fertilizer, (2) soil cultivated with rye grass without N fertilizer, (3) soil cultivated with rye grass with N fertilizer. The highest proportion of N in the extracts was the amino N fraction (amino acids + peptides) amounting to approximately 60% of the total N extracted by CaCl2 and to about 40% of the total N extracted by EUF. The proportion of amino sugars from total N extracted was in average 10% for the CaCl2 and 5.2% for the EUF extracts. The proportion of heterocyclic N bases derived from nucleic acids amounted in average to 4.8% and 3.6% for the CaCl2 and EUF extract, respectively. Amino N (amino acids + peptides) were correlated best with net N mineralization (EUF, r = 0.81***, CaCl2, r = 0.86***). The correlation between amino sugars and net N mineralization was r = 0.55* for the EUF extract and r = 0.49* for the CaCl2 extract. The heterocyclic N bases did not correlate with net N mineralization. Correlations between Norg extracted by CaCl2 versus net N mineralization were higher than those obtained by the EUF extract. Net N mineralization was about four times higher in the fallow soils than in the treatment with grass and no N fertilizer. In the treatment with grass + N fertilizer on average no net N mineralization occurred, moreover there was a tendency of N immobilization. It is assumend that in the treatments with grass cultivation, organic C released by roots stimulated the assimilation of mineral N and amino acids by soil microorganisms resulting in a low net N mineralization. Net N mineralization led to a highly significant depletion in the Norg pools and particularly in the amino N and amino sugar pools in the treatment with grass and without N fertilizer. This depletion was particularly evident in the CaCl2 extracts. The results justify the conclusion that the Norg obtained with both extraction methods originates from a dynamic N pool into which N flows in and out. The amino N extractable with EUF or CaCl2 is a reliable indicator for the net N mineralization potential of soils.  相似文献   
415.
We have previously characterized the development of vertebral fusions induced by elevated water temperature in Atlantic salmon. Molecular markers of bone and cartilage development together with histology were used to understand the complex pathology and mechanism in the development of this spinal malformation. In this study, we wanted to use proteomics, a non-hypothetical approach to screen for possible new markers involved in the fusion process. Proteins extracted from non-deformed and fused vertebrae of Atlantic salmon were therefore compared by two-dimensional electrophoresis (2DE) and MALDI-TOF analysis. Data analysis of protein spots in the 2DE gels demonstrated matrilin-1, also named cartilage matrix protein, to be the most highly up-regulated protein in fused compared with non-deformed vertebrae. Furthermore, real-time PCR analysis showed strong up-regulation of matrilin-1 mRNA in fused vertebrae. Immunohistochemistry demonstrated induced matrilin-1 expression in trans-differentiating cells undergoing a metaplastic shift toward chondrocytes in fusing vertebrae, whereas abundant expression was demonstrated in cartilaginous tissue and chordocytes of both non-deformed and fused vertebrae. These results identifies matrilin-1 as a new interesting candidate in the fusion process, and ratify the use of proteomic as a valuable technique to screen for markers involved in vertebral pathogenesis.  相似文献   
416.
The present study examined the protective effects of water chloride (Cl?) towards nitrite toxicity in Atlantic salmon parr during 84‐day long nitrite exposure. Effects on growth, histology, blood indices and gene expression were studied at a fixed nominal Cl? concentration of 200 mg/L and at several water nitrite concentrations (0, 0.5, 2, 5 and 10 mg/L NO2?–N). The specific growth rate was significantly reduced during the first three weeks at a Cl:NO2?–N ratio of 21:1, suggesting the activation of coping mechanisms at the later stages of the experiment. No significant effect of nitrite on gill histology and mortality was found. Nitrite accumulated in plasma; however, a Cl:NO2?–N ratio of 104:1 or higher prevented nitrite entry. The concentration of NO2?–N in plasma was significantly reduced at the end of the study, supporting the hypothesis of coping mechanisms. Cystic fibrosis transmembrane conductance regulator (cftr)‐1 showed a significant up‐regulation at highest nitrite concentration on day 22, and in three of the highest exposure groups at the end of the experiment. Our findings suggest that a Cl:NO2?–N ratio above 104:1 should be maintained through episodes of nitrite accumulation in water during the production of Atlantic salmon parr.  相似文献   
417.
The development of iron deficiency symptoms (growth depression and yellowing of the youngest leaves) and the distribution of iron between roots and leaves were investigated in different vine cultivars (Silvaner, Riparia 1G and SO4) grown in calcareous soils. As a control treatment all cultivars were also grown in an acidic soil. Only the cultivars Silvaner and Riparia 1G showed yellowing of the youngest leaves under calcareous soil conditions at the end of the cultivation period. All cultivars including SO4 showed severe shoot growth depression, by 50 % and higher, before yellowing started or without leaf yellowing in the cultivar SO4. Depression of shoot growth occurred independently from that of root growth. In a further treatment the effect of Fe‐EDDHA spraying onto the shoot growth of the cultivar Silvaner after cultivation in calcareous soil was investigated. Prior to Fe application plants were non‐chlorotic, but showed pronounced shoot growth depression. Spraying led to a significant increase in shoot length, though leaf growth was not increased. Accordingly, depression of shoot growth of non‐chlorotic plants under calcareous soil conditions and with ample supply of nutrients and water has been evidenced to be at least partly an iron deficiency symptom. We suggest that plant growth only partially recovered because of dramatic apoplastic leaf Fe inactivation and/ or a high apoplastic pH which may directly impair growth. Since growth was impaired before the youngest leaves showed chlorosis we assume that meristematic growth is more sensitively affected by Fe deficiency than is chlorophyll synthesis and chloroplast development. In spite of high Fe concentrations in roots and leaves of the vines grown in calcareous soils plants suffered from Fe deficiency. The finding of high Fe concentrations also in young, but growth retarded green leaves is a further indication that iron deficiency chlorosis in calcareous soils is caused by primary leaf Fe inactivation. However, in future, only a rigorous study of the dynamic changes of iron and chlorophyll concentration, leaf growth and apoplastic pH at the cellular level during leaf development and yellowing will provide causal insights between leaf iron inactivation, growth depression, and leaf chlorosis.<?show $6#>  相似文献   
418.
419.
Fulvic acids (FAs) from topsoil and ground water solutions were investigated to discover effects of land use and peat degradation on their molecular chemical composition and thermal properties. The FAs were extracted from three Gleysols under arable land, intensive and extensive grassland, and from three Histosols under alder forest, extensive grassland, and a natural succession in a long‐term (> 200 years) cultivated fen area. Functional groups and molecular subunits of the FAs were investigated by 13C Nuclear Magnetic Resonance (13C NMR) spectroscopy. Thermal properties and structural molecular subunits were investigated by off‐line pyrolysis, and Pyrolysis‐Field Ionization Mass Spectrometry (Py‐FIMS). The 13C NMR spectra showed that the FAs from topsoil solutions had smaller proportions of alkyl C (mean: —8 %) and more aromatic C (mean: + 6 %) than FAs from ground water. This clear differentiation of dissolved FAs in the soil profiles is consistent with Py‐FIMS data which have shown enrichments of lipids in ground water FAs. Furthermore, Py‐FIMS revealed that the FAs from topsoils were richer in phenols + lignin monomers, carbohydrates, as well as mostly aromatic N‐containing compounds. These molecular subunits of FAs, relatively enriched in topsoil, were also the main indicators of land use and peat degradation. For topsoil solutions, the proportions of phenols + lignin monomers and carbohydrates increased stepwise with peat degradation in Gleysols and Histosols. Correspondingly, the thermal properties indicated the incorporation of these compounds into FAs by chemical bonds of larger thermal stability. Statistical evaluation by principal component analysis of Py‐FIMS clearly supported the differentiation of FAs according to the origin from topsoils and ground water, different soil types, and land use and peat degradation. Hence, it is concluded that water soluble FAs can be utilized as objective ecological indicators for soil effects on adjacent ground and surface waters.  相似文献   
420.
Zusammenfassung Beim TeppichkäferAnthrenus flavipes wurde durch Selektionsdruck mit Permethrin Resistenz erzeugt. Die Resistenzentwicklung wurde in einer Standard-Testserie mit bekanntem Permethrin-Gehalt über eine Dauer von 4,3 Jahren an der Fraßleistung gemessen und mit der des Normalstammes verglichen. Die Auswertung der Resultate erfolgte in absoluten Werten der Gewichtsverluste (mg) und in relativen Werten der Schutzwirkungs-Effekte (E%).Außerdem wurde die Resistenzentwicklung bei der KleidermotteTineola bisselliella durch Permethrin und Motten-und Käferschutzmittel auf der Basis von Fraßgiften untersucht.Gemessen an der absoluten Fraßleistung ergab sich beim Resistenz-Stamm vonA. flavipes nach 22 Generationen ein 70facher Resistenzfaktor. Um einen 85%igen Schutzwirkungs-Effekt zu erreichen (Toleranzgrenze der Käferechtheit nach SNV 195'901), mußte die Einsatzkonzentration von Permethrin um das 4fache erhöht werden. T. bisselliella zeigte bei Permethrin und den Fraßgiften MITIN FF resp. EULAN U 33 trotz jahrelanger Bemühungen keine Neigung zu Resistenzbildung.Die Bezeichnungen MITIN (CIBA-GEIGY), EULAN (BAYER), PERIGEN (WELLCOME) und SMA-V (VICKERS) sind geschützte Marken der entsprechenden Firmen.
Permethrin-resistance in the carpet beetle,Anthrenus flavipes Casey (Col., Dermestidae)
Resistance to Permethrin inAnthrenus flavipes, was induced by selective pressure. Development of resistance over a period of 4.3 years was measured as feeding performance in a standard test series of known Permethrin content and compared with that of the normal sensitive strain. The findings were expressed both as absolute values of weight loss and also as relative Protection-Efficacy (E%).Development of resistance in the clothes-moth,Tineola bisselliella, was also evaluated with Permethrin as well as with moth- and beetle-proofing agents based on stomach poisons.On the basis of feeding performance a 70-fold increase in resistance withAnthrenus flavipes was evident after 22 generations. In order to achieve 85% Protection-Efficacy (tolerance for beetle-proofing according to SNV 195'901, 1971) a four-fold increase in Permethrin concentration was necessary. Tineola bisselliella showed no tendency to develop resistance to Permethrin and the stomach poisons ®MITIN FF and ®EULAN U 33 despite years of exposure.


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