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151.
Using saturated or enriched zeolites as slow release fertilizers (SRFs) is considered as an environmental-friendly strategy to enhance use of macronutrients in sandy soils. In this paper, two natural zeolites, clinoptilolite (CLI) and chabazite (CHA) were used as mineral precursors to prepare NH4+/K+ saturated clinoptilolite (NH4+/K+-CLI) and chabazite (NH4+/K+-CHA) as zeolitic nutrient sources (ZNSs). Comparison between the nutrient retention capabilities of these ZNSs was one of the main objectives of this study. The NH4+/K+-CLI and NH4+/K+-CHA were prepared by soaking the zeolites in NH4Cl and KCl solutions, respectively. Leaching tests were performed on a sandy soil amended with chemical fertilizers (CFs), NH4+/K+-CLI and NH4+/K+-CHA to evaluate the leaching properties of them. The results indicated that approximately 84% and 88% of the NH4+ and K+ of soils fertilized with CFs were lost during the experiment, respectively. While, the NH4+ and K+ losses from soils amended with NH4+/K+-CLI and NH4+/K+-CHA were 29%, 23%, and 14%, 24%, respectively. Despite of drastic changes in leaching behavior of CFs, nutrient losses from ZNSs were more uniform during the experiments. No significant difference was found between the two studied zeolites on reduction of K+ loss. However, CHA was more effective in preventing NH4+ loss during leaching.  相似文献   
152.
Seedlings of Phillyrea latifolia L., a Mediterranean shrub, were exposed for 90 days to 110 nl l(-1) ozone (O(3)). Comparison of the cDNA-amplified fragment length polymorphism (cDNA-AFLP) patterns for treated and control plants allowed the identification and cloning of 88 differential sequences induced by O(3). The differential expression of 67 cloned sequences was further confirmed by RT-PCR. The functions of 36 cloned sequences, corresponding to seven of the twelve gene functional classes of Arabidopsis, were presumed on the basis of their homology with characterized gene sequences. Ozone induction of genes homologous to 24 of the clones has been reported in other plant species, whereas the induction of the 12 remaining sequences has not been observed before. Ozone activation of these newly identified genes could be a result of the chronic exposure to low O(3) concentration, because in most previous studies, acute treatments, involving high O(3) dosages, were applied. Possible roles of the cloned sequences in the response of P. latifolia to O(3) and other causes of oxidative stress are discussed.  相似文献   
153.
Recent morphological and molecular evidence has changed interpretations of arthropod phylogeny and evolution. Here we compare complete mitochondrial genomes to show that Collembola, a wingless group traditionally considered as basal to all insects, appears instead to constitute a separate evolutionary lineage that branched much earlier than the separation of many crustaceans and insects and independently adapted to life on land. Therefore, the taxon Hexapoda, as commonly defined to include all six-legged arthropods, is not monophyletic.  相似文献   
154.
Abstract. Twenty malignant lymphomas of northern pike, Esox lucius L., from the Baltic coast of Estonia were investigated immunohistochemically using rabbit anti-human polyclonal antibodies against lysozyme (LYS), alpha-1-antichymotrypsin (ACT) and S-100 protein. Based on the strongly positive reactions to LYS, ACT and S-100 found in a great number of histiocytes, two of these tumours were classified as histocytic diffuse malignant lymphomas. Furthermore, the weaker positive reaction to these antibodies detected in some of the histocytes in 10 other cases of diffuse malignant lymphoma indicates their histocytoid-lymphocytic origin. In addition, the lack of reaction to all antibodies used found in the remaining eight tumours, as well as their general morphological structure, allowed their diagnosis as lymphocytic diffuse malignant lymphomas. Thus, the immunohistochemical reactions to LYS, ACT and S-100 served as a tool for precisely distinguishing between the different types of lymphomas as well as for better understanding their origin.  相似文献   
155.
A 3-yr-old male Gouldian finch (Erythrura gouldiae) died after 2 wk of lethargy, emaciation, feather loss, and abdominal distension. The bird was housed in an aviary for breeding, but it had shown loss of fertility in the previous breeding season. Necropsy revealed a gross, firm, and yellow mass involving the left testis. Histologically, the mass was a mixed form, intratubular and diffuse, Sertoli cell tumor. Some neoplastic cells had intranuclear inclusion bodies that immunoelectron microscopy proved to be polyomavirus particle aggregates. There were no viral inclusions in other tissues. The possible role of infection in the pathogenesis of the tumor is discussed.  相似文献   
156.
The kinetics of heat treatment as well as its effect on some physical and mechanical properties of poplar wood (Populus alba L.) were analysed in this research. Kinetic tests were performed at different treatment temperatures and two different air ventilation settings [low and high air exchange rate (AER) with the exterior]. The treatment kinetics was studied, starting from the oven-dry condition, according to the mass loss during time. The time–temperature equivalency was checked, the mass loss versus time formalised through a master curve. The analysis clearly showed how the heat treatment at low and high AER presents different degradation kinetics even if similar activation energy values were found. Some physical and mechanical properties of wood after treatments up to a mass loss of 7 and 10 % starting from oven-dry or standard environmental conditions state were also studied. All of the treated samples showed statistically significant differences compared to the untreated one. The treatments performed at 7 or 10 % of dry mass loss showed homogeneous behaviour. The same tendency was observed for the treatments starting at oven-dry or standard environmental conditions with the exception of Young’s modulus, which resulted in smaller reductions in wet starting condition when compared to dry samples.  相似文献   
157.
  1. Effectiveness of restoration/repopulation measures may be strongly hindered by the ability of the target species to cope with the environmental conditions of the receiving area.
  2. Although a species has been reported previously for a given area, the environmental conditions and human pressures may have changed, potentially making any restoration attempt ineffective. Evidence is provided showing that the endangered ferruginous limpet Patella ferruginea can complete its reproductive cycle in the northernmost sector of the western Mediterranean.
  3. This supports the idea that the reintroduction and the strict protection of P. ferruginea in the extreme north of its historical geographic range could be effective for the recovery of the species in this area and ultimately the establishment of reproductively viable and stable populations.
  4. Verification of gonadal maturation of specimens experimentally established on the Gulf of Genoa (Ligurian Sea) coastline, as well as evidence of sex change in one individual (the first outside the Alboran Sea), provides further support of the potential for individuals to complete their reproductive cycle in this area.
  5. The results support the potential of actions for the restoration of viable populations of the species along the Ligurian coasts through the introduction of juveniles obtained exclusively by aquaculture techniques, in order to mitigate any impact on donor sites.
  相似文献   
158.
Abstract The development of the fin skeleton has been studied in both the wild and hatchery sea bass, Dicentrarchus labrax L., larvae, in order to identify and define morphofunctional criteria for larval quality assessments. The cartilaginous and bony skeletal elements of the larvae were studied and standard length and notochord flexure recorded. Fin anomalies were present in reared larvae, whereas they were rare or absent in specimens from the wild. These anomalies were recognizable from the very beginning of skeletal development, indicating that environmental, genetic and broodstock management factors influence even the very early stages of larval development.  相似文献   
159.
Abstract. The possibility of using eels from intensive rearing ponds to restock natural basins has been investigated by comparing growth, survival and rate of yellow-to-silver metamorphosis of 'wild type' eels and of eels from an intensive rearing pond. A total of 2243 marked eels were released into a closed natural environment of 22ha; 1254 were wild type (average length 45·6 ± 9·0cm), and 989 from an intensive rearing pond, split by a mechanical grader in two groups. The first group was made of 617 well-growing eels (44·9 ± 3·0cm), the second one of 372 smaller eels (36·9 ± 4·3cm) which had not adapted to the artificial conditions.
The starting size being equal the animals grew to the same extent; in some cases the animals previously adapted to the artificial pond grew better than the wild type. The rate of metamorphosis from yellow to silver eel was 28·4% for the wild type eels and 22% for the others, although the latter became mostly silver males. Survival of the wild type eels (starting with the 35-cm size class and covering the period from April to December) was calculated by mark-recapture at approximately 98·6%. For the eels previously well adapted to the intensive rearing pond it was only 85%, indicating some difficulty in competing in the natural environment. The good growth shown by the smaller eels, with a survival of about 90%, would seem to indicate that these animals might be effectively used for restocking purposes, thus favouring an integration between the intensive ponds and the extensive environments.  相似文献   
160.
The wide diffusion of tropospheric ozone is a major environmental problem, in urban area as well as in rural and remote localities. Its increasing man-related levels are connected to severe impacts on human life and welfare, in terms of adverse health effects, damage to manufacts and injury to plants. Biological monitoring is a powerful tool for filling the gap between the causes and the effects of environmental toxins, as bioindication agents assess in an easy-to-detect fashion the effects of pollution on (selected) biota. A project was launched in 2012 to involve some 190 students (ages 11–16) from three schools in Central Italy in biodetection of ozone effects with the hypersensitive plant Nicotiana tabacum Bel-W3. The project also involved teachers and families of the pupils. Results implied the reading of 12,000 biological data (ozone injury on cotyledons) and were fortified by data captured by four automatic analyzers (1300 raw data of hourly means). Biological and chemical data compared favorably and were treated with geostatistical methods; results are exposed in the form of cartographic restitutions. Under the guidance of their teachers, the pupils had several opportunities to practice with many basic and applied study areas and disciplines and were initiated into the scientific method in a simple and absorbing manner. Though primarily an educational exercise, the survey provided sound research elements and the picture of pollution that emerged has increased the knowledge of air quality in the area. Biomonitoring is confirmed to be a powerful tool to involve young people in environmental topics.  相似文献   
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