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61.
Mares with uncomplicated pregnancies (n = 33) underwent transabdominal sonography to evaluate fetal well-being, obtain measurements of fetal size and characterize the intrauterine environment. Data from the last examination obtained prior to parturition were used for statistical analysis. All mares had one active fetus with good fetal tone. The maximal vertical depth of amniotic fluid (7.9 ± 3.5 cm) was less than allantoic (13.4 ± 4.4 cm) and fewer echogenic particles were detected in amniotic fluid. The maximal uteroplacental thickness was 1.38 ± 0.23 cm (retrospective) and 1.15 ±± 0.24 cm (propspective). In 3 mares small anechoic spaces were imaged between the uterus and placenta. Fetuses had a regular cardiac rhythm with a mean heart rate of 75 ± 7 beats/minute and breathing movements. The diameter of the fetal aorta (mean = 22.8 ± 2.15 mm) was significantly correlated with neonatal foal weight (P<0.0008, r = 0.72) and maternal prepartum weight (P<0.002, r = 0.86). This information of the normal intrauterine environment and fetal well-being can be used to develop a biophysical profile specific for the equine fetus.  相似文献   
62.
The effect of chlorine-induced bacterial injury on spectral features using Fourier transform infrared (FT-IR) absorbance spectroscopy was studied using a mixed bacterial culture of (1:1) ca. 500 CFU/mL each Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 15442 in 0.9% saline. Bacterial cells were treated with 0, 0.3, or 1.0 ppm of initial free chlorine (21 degrees C, 1 h of contact time). Chlorine-injured and dead bacterial cells retained the ATR spectral properties of uninjured or live cells in the region of C-O-C stretching vibrations of polysaccharides, indicative of the cell wall peptidoglycan layer and lipopolysaccharide outer leaflet. This confirms the observations of others that extensive bacterial membrane damage is not a key factor in the inactivation of bacteria by chlorine. The bactericidal effect of chlorine caused changes in the spectral features of bacterial ester functional groups of lipids, structural proteins, and nucleic acids, with apparent denaturation reflected between 1800 and 1300 cm (-1) for injured bacterial cells. Three-dimensional principal component analysis (PCA) showed distinct segregation and clustering of chlorine-treated and untreated cells. Cells exposed to chlorine at 0.3 or 1.0 ppm could be distinguished from the untreated control 73 and 80% of the time, respectively, using soft independent modeling of class analogy (SIMCA) analysis. This study suggests that FT-IR spectroscopy may be applicable for detecting the presence of injured and viable but not culturable (VBNC) waterborne pathogens that are underestimated or not discernible using conventional microbial techniques.  相似文献   
63.
There is great interest in the potential chemopreventive activity of resveratrol against human cancers. However, there are conflicting results on its growth inhibitory effect on normal cells. This project examined the differential effect of resveratrol at physiologically relevant concentrations on nonmalignant (WIL2-NS) and malignant (HL-60) cell lines and compared the underlying mechanisms via cell cycle modulation, apoptosis induction, and genotoxicity potential. Twenty-four hours of exposure to resveratrol was toxic to WIL2-NS and HL-60 cells in a dose-dependent manner. WIL2-NS cells regrew 5 times more than HL-60 cells by 120 h after the removal of 100 microM resveratrol (p < 0.05). Furthermore, significant alterations in cell cycle kinetics were induced by resveratrol in HL-60 cells, but were to a lesser extent for WIL2-NS cells. The proportion of apoptosis was also 3 times higher in HL-60 cells as compared to WIL2-NS cells for 100 microM resveratrol (p < 0.05). In conclusion, resveratrol preferentially inhibited the growth of HL-60 cells via cell cycle modulation and apoptosis induction and subsequently directed the cells to irreversible cell death, whereas the effect on WIL2-NS cells was largely reversible.  相似文献   
64.
Journal of Soils and Sediments - Knowledge about the spatio-temporal variability of soil microbial properties is crucial in evaluating their structure-function relationship and their impact on...  相似文献   
65.
Using an automated gas chromatography system coupled with an online sampling/thermal desorption module, benzene, toluene, and their alkylated derivatives were measured in Las Vegas, Nevada from 3 July to 28 August 2008. The levels of hydrocarbons were comparable to those typically found in urban environments. Statistically significant (at 95?% level) higher concentrations were measured on mid-week days as compared with those measured during weekends. This was correlated to a local traffic pattern rather than traffic on highways. The concentrations of aromatic hydrocarbons also increased during periods when transport of smoke from wildfires in central and north California was identified by remote sensing but these levels were comparable to other days with volatile organic compounds concentrations. The high toluene/benzene ratios and the estimated photochemical age of air masses implied the contribution of other local sources. Fuel evaporation accounted for the vast majority of toluene enhanced concentrations in early July (as compared with those measured in June) for sites within the urban grid, but very little for sites located outside the urban area.  相似文献   
66.
Deamidation of amide residues, Asn and Gln, in collagen occurs during the manufacture of B-type gelatin and could affect the performance of B-type gelatins as it may affect the refolding of triple-helical junctional domains that are formed during gelation. Host-guest peptides of the form acetyl-(Gly-Pro-Hyp)3-Gly-Xaa-Yaa-(Gly-Pro-Hyp)4-Gly-Gly-amide, where the X- and Y-positions of the guest peptide are varied, have been used to examine the effect of changing Asn to Asp and Gln to Glu on triple-helix stability. This paper reports the stability of host-guest peptides containing the guest triplets Gly-Ala-Asn, Gly-Asn-Ala, Gly-Asn-Lys, Gly-Gln-Ala, Gly-Glu-Glu, and Gly-Leu-Glu. In combination with previous data, these now provide 15 pairs of peptides in which the effect of deamidation can be compared. These comparisons show that the deamidation of Asn to Asp, regardless of whether it occurred in either the X- or Y-position, always gave a stabilizing effect; deamidation of Gln in the X-position also led to an increase in stability. In contrast, deamidation of Gln in the Y-position was quite distinct, leading to destabilization. The higher observed frequency of Gln in the Y-position compared with other amides may account for the slight destabilization of collagen following deamidation.  相似文献   
67.
The evaluation of DNA damage in aquatic organisms represents one of the most widely used biomarkers in the assessment and monitoring of marine pollution. Our previous research highlighted the presence of DNA damage in hepatic nuclei and blood cells of Coris julis specimens collected from Augusta harbor (Syracuse, Italy), a site highly polluted. In this work, we investigated on the ability of different natural compounds with antioxidant and immunostimulating properties, such as resveratrol (50 μM, 100 μM), amygdalin (100 μM, 200 μM), and Urtica dioica roots extract (50 and/or 100 μg/ml), in reducing DNA damage of C. julis. Blood cells were analyzed by atypical cellular comet assay. The results confirmed that Augusta specimens are the most damaged and showed that resveratrol, followed by amygdalin and U. dioica roots extract, drastically reduced DNA damage. This finding evidences the effectiveness of three natural compounds for DNA protection suggesting the possible use of feed enriched with antioxidant compounds in aquaculture practices for organisms damaged by natural and anthropic insults.  相似文献   
68.
In the period 1994–1996 a post-harvest survey was conducted in wheat, barley and oats to assess the occurrence and geographic distribution of Fusarium species in Norwegian cereals. The number of samples investigated was adjusted proportionally to the production of each cereal species within the regions. A total of 695 grain samples were analysed. The amount of Fusarium infection varied with cereal species and region of origin. The most frequently isolated Fusarium spp. from all samples were F. avenaceum, F. poae, F. tricinctum and F. culmorum. Other important toxigenic Fusarium spp. were F. graminearum, “powdery F. poae”, F. equiseti and F. sporotrichioides. A north-south gradient was valid for F. tricinctum, F. poae and in 1994 for “powdery F. poae”. In 1994 “powdery F. poae” was the most abundant potential producer of HT-2 and T-2 toxins in Norwegian cereals. Distribution of F. graminearum and F. culmorum demonstrated in this study, corresponded to previously reported DON-distribution, although DON seems to be produced by different species in different regions. Distribution of the isolated Fusarium species and comparison between cereals and locations are discussed.  相似文献   
69.
Naphthenic acids (NAs) are a complex group of naturally occurring oil sands constituents that constitute a significant portion of the dissolved organic carbon (DOC) pool available for microbial degradation in the process-related waste water associated with oil sands mine sites. One approach to understanding the biological fate of oil sands process-derived carbon and nitrogen in aquatic reclamation of the mine sites involves the use of stable isotope analyses. However, for stable isotope analyses to be useful in such field-based assessments, there is a need to determine how microbial degradation of a complex mixture of NAs might change the stable isotope values (δ 13C, δ 15N). In batch cultures and semi-continuous laboratory microcosms, utilization of a commercial mixture of NAs by oil sands-derived microbial cultures resulted in microbial biomass that was similar or slightly 13C enriched (1.4‰ to 3.0‰) relative to the DOC source, depending on the length of incubation. Utilization of a NA-containing extract of oil sands processed water resulted in greater 13C enrichment of microbial biomass (8.5‰) relative to the DOC source. Overall, the δ 13C of the DOC comprised of complex mixtures of NAs showed minimal change (?0.5‰ to ?0.1‰) during the incubation period whereas the δ 13C of the dissolved inorganic carbon (DIC) was more variable (?5.0‰ to +5.4‰). In tests where the concentration of available nitrogen was increased, the final biomass values were 15N enriched (3.8‰ to 8.4‰) relative to the initial biomass. The isotope trends established in this study should enhance our ability to interpret field-based data from sites with hydrocarbon contamination, particularly in terms of carbon source utilization and 15N enrichment.  相似文献   
70.
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