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11.
Yu X  Chini CC  He M  Mer G  Chen J 《Science (New York, N.Y.)》2003,302(5645):639-642
The carboxyl-terminal domain (BRCT) of the Breast Cancer Gene 1 (BRCA1) protein is an evolutionarily conserved module that exists in a large number of proteins from prokaryotes to eukaryotes. Although most BRCT domain-containing proteins participate in DNA-damage checkpoint or DNA-repair pathways, or both, the function of the BRCT domain is not fully understood. We show that the BRCA1 BRCT domain directly interacts with phosphorylated BRCA1-Associated Carboxyl-terminal Helicase (BACH1). This specific interaction between BRCA1 and phosphorylated BACH1 is cell cycle regulated and is required for DNA damage-induced checkpoint control during the transition from G2 to M phase of the cell cycle. Further, we show that two other BRCT domains interact with their respective physiological partners in a phosphorylation-dependent manner. Thirteen additional BRCT domains also preferentially bind phospho-peptides rather than nonphosphorylated control peptides. These data imply that the BRCT domain is a phospho-protein binding domain involved in cell cycle control.  相似文献   
12.
Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars.  相似文献   
13.
14.
Papua New Guinea has astonishing biological and cultural diversity which, coupled with a strong community reliance on the land and its biota for subsistence, add complexity to monitoring and conservation and in particular, the demonstration of declines in wildlife populations. Many species of concern are long-lived which provides additional challenges for conservation. We provide, for the first time, concrete evidence of a substantive decline in populations of the pig-nosed turtle (Carettochelys insculpta); an important source of protein for local communities. Our study combined matched village and market surveys separated by 30 years, trends in nesting female size, and assessment of levels and efficacy of harvest, each of which was an essential ingredient to making a definitive assessment of population trends. Opportunities for an effective response by local communities to these declines needs to consider both conservation and fisheries perspectives because local communities consider the turtle a food resource, whereas the broader global community views it as a high priority for conservation. Our study in the Kikori region is representative of harvest regimes in most rivers within the range of the species in Papua New Guinea, and provides lessons for conservation of many other wildlife species subject to harvest.  相似文献   
15.
Root growth of winter barley was studied on 2 Belgian silt loam soils after subsoiling to 60 cm depth. In the first field (well-drained) rooting depth increased significantly after removal of a plough pan. At the flowering stage, total root weight in the soil layers between 25–50 cm and 50–75 cm was 125% and 325%, respectively, higher on the subsoiled plots than on the control. The P2O5 and K2O concentrations in the roots were significantly increased by 20% and 40%, respectively. In the second field (imperfectly drained) with initially relatively high bulk densities in the subsoil, the influence of subsoiling was negligible. In this study, the clearly-shown root-growth retardation that resulted in a lower yield on the control, seemed to be caused by the high penetration resistance in the plough sole (> 3MPA) rather than poor aeration status induced by the high bulk densities.  相似文献   
16.
The aim of this laboratory study was to investigate the effect of straw and vinasses on the nitrogen (N) mineralization-immobilization turnover of celery residues during two periods (each simulating a time period from autumn till spring) under laboratory conditions. During the first period (1-198 d), 15N-labelled celery residues (1.1 g dry matter (DM) kg−1 soil) were incubated together with straw (8.1 g DM kg−1 soil), aiming to immobilize the N released from celery residues, followed by an incorporation of vinasses (1.9 g DM kg−1 soil) after 84 d, with a view to remineralizing the immobilized celery-N. During the second period (198-380 d), the experimental set-up was repeated, except that non-labelled celery residues were used. Total N, mineral N and their 15N enrichments as well as microbial biomass N were determined at regular time intervals. During both periods, mixing celery residues with straw significantly increased microbial biomass N (90.5 and 40.5 mg N kg−1 extra compared to celery only treatment) and decreased the amount of mineral N (reduction of 56.1 and 45.9 mg N kg−1 soil compared to celery only treatment) and the celery-derived mineral 15N (0% of mineral celery-derived 15N in straw treatment compared to 35% of mineral celery-derived 15N in celery only treatment). After maximum immobilization, a natural remineralization (without addition of vinasses) of 32.2 (at day 198) and 11.1 mg N kg−1 soil (at day 380) occurred in the straw treatment, but the mineral N content remained significantly lower than in the celery only treatment during the complete experiment, and the amount of remineralized celery-15N was very low (5.4% of celery-derived 15N after 380 d). Vinasses caused no real priming effect, although it did slightly increase the amount of remineralized celery-15N (+6.4% of celery-derived 15N at day 380 compared to the straw treatment), probably due an apparent added N interaction caused by displacement reactions with the soil microbial biomass.  相似文献   
17.
Abstract. To study the change in soil organic carbon (SOC) since it was recorded during the Belgian National Soil Survey some 40 years ago, we recently revisited 939 locations still under use as arable land. The study area comprised almost the entire province of West Flanders (about 3000 km2) characterized by profound changes in its arable land management. Taking the increased ploughing depth (by 9.8 cm on average) into account, a significant (P= 0.001) increase of the SOC content by 0.2% on average was found. Expressed as an amount, the SOC in the topsoil rose by 9.3 t/ha on average, representing an increase of 25%. This is comparable with the conversion of arable land into grassland for 2 to 3 decades. Geostatistical tools were used to map the SOC at the two times of observation. These showed that most of the spatial variation occurred within about 4 km. Since the community level is the smallest spatial resolution on which agricultural statistics are gathered officially, a detailed modelling of the change in SOC was impossible. However, by selecting communities with extreme changes in SOC, we found indications that the major source of increase in SOC was due to the large increase in pig breeding.  相似文献   
18.
The metabolism of benomyl was studied in carrots treated with high rates of benomyl, and in strawberries and apples treated at normal rates. The same metabolites were observed in both cases though, at normal rates, their concentrations were low but significant. Detected by means of gas-liquid chromatography they were: carbendazim, 2-aminobenzimidazole (2-AB), benzimidazole, 2-aminobenzonitrile, o-phenylene-diamine and the conjugates of carbendazim and 2-AB. o-Phenylenediamine has not hitherto been reported as a metabolite of benomyl. Two unidentified compounds were also observed by gas-liquid chromatography; their mass spectra were obtained by means of combined gas-liquid chromatography and mass spectrometry.  相似文献   
19.
A new acidic derivative of the fungicide fenpiclonil was synthesized containing a methyl group on the alpha-position of the carboxyl function of N-carboxymethyl-3-cyano-4-(2,3-dichlorophenyl)pyrrole. The phloem mobility of the resulting N-(1-carboxyethyl)-3-cyano-4-(2,3-dichlorophenyl)pyrrole was comparable with that of the former compound, but was higher at external pH 5.0. Unlike the derivatives previously synthesized, it was comparable with fenpiclonil in its fungicidal activity against the pathogenic fungus Eutypa lata.  相似文献   
20.
A sheep-pox virus strain has been adapted and multiplied in primary lamb kidney cell cultures. The main characteristics of the strain have been verified in vitro after clones were isolated, and the results confirmed its identity. The safety and the potency of the strain have been investigated in sheep.

The inoculation of the strain to sheep was followed by a post-vaccinal reaction materialised by a nodule at the site of inoculation and an increase of temperature by about 1°C. No reactions adversely affecting pregnancy have been noted. Immunisation was demonstrated by an increase in the level of neutralising serous antibodies and protection against the pathogenic virus. The immunity tended to decrease during the second year after primovaccination and a yearly booster vaccination appeared to be necessary. Primovaccination of lambs over 2 months of age produced a better immunity, especially when the lambs were born from vaccinated ewes.

This strain forms the active principle of a freeze-dried vaccine containing no adjuvant of the immunity.  相似文献   

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