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331.
Fatty acid composition and stable isotope ratios of carbon (delta(13)C) and nitrogen (delta(15)N) were determined in muscle tissue of turbot (Psetta maxima). The multivariate analysis of the data was performed to evaluate their utility in discriminating wild and farmed fish. Wild (n=30) and farmed (n=30) turbot of different geographical origins (Denmark, The Netherlands, and Spain) were sampled from March 2006 to February 2007. The application of linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA) to analytical data demonstrated the combination of fatty acids and isotopic measurements to be a promising method to discriminate between wild and farmed fish and between wild fish of different geographical origin. In particular, IRMS (Isotope Ratio Mass Spectrometry) alone did not permit us to separate completely farmed from wild samples, resulting in some overlaps between Danish wild and Spanish farmed turbot. On the other hand, fatty acids alone differentiated between farmed and wild samples by 18:2n-6 but were not able to distinguish between the two groups of wild turbot. When applying LDA isotope ratios, 18:2n-6, 18:3n-3, and 20:4n-6 fatty acids were decisive to distinguish farmed from wild turbot of different geographical origin, while delta(15)N, 18:2n-6, and 20:1n-11 were chosen to classify wild samples from different fishing zones. In both cases, 18:2n-6 and delta(15)N were determinant for classification purposes. We would like to emphasize that IRMS produces rapid results and could be the most promising technique to distinguish wild fish of different origin. Similarly, fatty acid composition could be used to easily distinguish farmed from wild samples.  相似文献   
332.
Brassica vegetables are attracting major attention as healthy foods because of their content of glucosinolates (GLs) that release the corresponding isothiocyanates (ITCs) upon myrosinase hydrolysis. A number of studies have so far documented the chemopreventive properties of some ITCs. On the other hand, single nutrients detached from the food itself risk being somewhat "reductive", since plants contain several classes of compounds endowed with a polyhedral mechanism of action. Our recent finding that 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) and 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC), released by the GLs purified from Japanese (Kaiware) Daikon (Raphanus sativus L.) seeds and sprouts, had selective cytotoxic/apoptotic activity on three human colon carcinoma cell lines prompted further research on the potential chemopreventive role of a standardized Kaiware Daikon extract (KDE), containing 10.5% w/w GRH and 3.8% w/w GRE, compared to its isolated components. KDE administered in combination with myrosinase at doses corresponding to 50 microM GRH-ITC plus 15 microM GRE-ITC (50 microM KDE-ITC) to three human cancer cell lines (LoVo, HCT-116 and HT-29) significantly reduced cell growth by 94-96% of control in six days (p < 0.05), outperforming pure GRH-ITC or GRE-ITC at the same dose. On the other hand, the same treatment had no significant toxicity on normal human T-lymphocytes. A 50 microM concentration of KDE-ITC had relevant apoptosis induction in all tested cancer cell lines, as confirmed by annexin V assay (e.g., 33% induction in LoVo compared to control, p < 0.05), Bax protein induction (e.g., +20% in HT-29, p < 0.05), and Bcl2 downregulation (e.g.-20% in HT-29, p < 0.05), and induced caspase-1 and PARP-1 activation in all cancer cells as shown by Western blot analysis. Unlike pure GRH or GRH-ITC, KDE also had significant chain-breaking antioxidant activity, retarding the AAPH-initiated autoxidation of methyl linoleate in SDS micelles at concentrations as low as 4.4 ppm (-50% in oxygen consumption rate), as monitored by Clark-type microelectrode oxygen-uptake kinetics, and induced very fast quenching of DPPH. radical in methanol with t(1/2) (s) = (1.47 +/- 0.25) x 10(-2)/[KDE; (g/L)], measured by stopped-flow UV-vis kinetics at 298 K. The potential chemopreventive role of KDE is discussed.  相似文献   
333.
The hydroalcoholic extract of Maytenus krukovii bark was investigated for its in vitro mutageno-protective activities by means of the Ames Salmonella/microsome assay. The extract showed an inhibitory effect in both T98 and T100 strains against the mutagenic activity of promutagen 2-aminoanthracene but was not protective against directly acting mutagens sodium azide and 2-nitrofluorene. When tested as a radical scavenger and antioxidant it produced a dose-dependent inhibition. The extract did not show significant antibacterial properties, and was weakly active against dermatophyte and phytopathogenic fungi, but inhibited the growth of phytopathogen Pithyum ultimum.  相似文献   
334.
The potential of Fourier transform mid-infrared spectroscopy (FT-MIR) using an attenuated total reflectance (ATR) cell was evaluated for the authentication of 11 unifloral (acacia, alpine rose, chestnut, dandelion, heather, lime, rape, fir honeydew, metcalfa honeydew, oak honeydew) and polyfloral honey types (n = 411 samples) previously classified with traditional methods such as chemical, pollen, and sensory analysis. Chemometric evaluation of the spectra was carried out by applying principal component analysis and linear discriminant analysis, the error rates of the discriminant models being calculated by using Bayes' theorem. The error rates ranged from <0.1% (polyfloral and heather honeys as well as honeydew honeys from metcalfa, oak, and fir) to 8.3% (alpine rose honey) in both jackknife classification and validation, depending on the honey type considered. This study indicates that ATR-MIR spectroscopy is a valuable tool for the authentication of the botanical origin and quality control and may also be useful for the determination of the geographical origin of honey.  相似文献   
335.
The importance of demographic niches to tree diversity   总被引:1,自引:0,他引:1  
Most ecological hypotheses about species coexistence hinge on species differences, but quantifying trait differences across species in diverse communities is often unfeasible. We examined the variation of demographic traits using a global tropical forest data set covering 4500 species in 10 large-scale tree inventories. With a hierarchical Bayesian approach, we quantified the distribution of mortality and growth rates of all tree species at each site. This allowed us to test the prediction that demographic differences facilitate species richness, as suggested by the theory that a tradeoff between high growth and high survival allows species to coexist. Contrary to the prediction, the most diverse forests had the least demographic variation. Although demographic differences may foster coexistence, they do not explain any of the 16-fold variation in tree species richness observed across the tropics.  相似文献   
336.
Nine genic SSR loci were used to evaluate the genetic diversity and identify accessions in wild Italian Humulus lupulus L., in comparison with widely cultivated European and U.S. commercial cultivars. A collection of 80 wild hop samples from Italy and 43 hop cultivars from Europe and U.S., were characterized. Allelic frequency analysis revealed 65 distinct Italian genotypes and differentiated all the commercial cultivars; moreover, specific alleles were observed for wild and cultivated hops. The number of alleles identified in the wild population were 104 and 123 within all the accessions. The maximum polymorphic information content was evidenced for locus HlGA23 in the Italian wild population and in the whole set of accessions (0.905 and 0.902 respectively). The dendrogram constructed from Euclidean distance with the UPGMA method showed two main clusters, one including commercial American and European accessions and one mostly composed by wild Italian accessions. Model-based clustering (Bayesian method) placed the accessions into five germplasm groups, one of which was characterized by Italian genotypes only. The study showed for the first time the great biodiversity present in Italy, and the remarkable differences with European and American hops. It was also found that within the population of north-central Italy a large genetic variability is present, suited to be studied and exploited; this genetic wealth could be used in future breeding programs in order to develop new hop varieties carrying characteristics useful for brewers.  相似文献   
337.
Corn stands out among the cultivars because of its high importance in food, animal feed and raw materials for energy production. The quantity and quality of the harvested grain can be reduced, mainly due to inadequate weed management. Nowadays, weed control is accomplished with the use of herbicides as pre‐emergence and postemergence, applied alone or in a tank mix. This study aimed to evaluate the efficiency of the control of weeds and phytotoxicity of the herbicides that were applied in tank mix or isolated in the corn hybrids, Formula TL® and SYN 7B28 . Two experiments were conducted: in the 2012/2013 season (Formula TL®) and 2013/2014 season (SYN 7B28). There was a low initial phytotoxicity of all the tested herbicides in the initial evaluation; however, from 14 days after treatment, it was minimal. The weed control of Ipomoea indivisa, Urochloa plantaginea and Euphorbia heterophylla in both experiments was better, in general, when using the tank mixtures of atrazine + simazine + tembotrione and atrazine + simazine + mesotrione, respectively. The application of atrazine + simazine + tembotrione in the SYN 7B28 hybrids provided, with the exception of the thousand‐grain weight, the best expression of grain yield components, combining a low phytotoxicity and best control of the weeds. The Formula TL® hybrid presented the highest mass of a thousand grains and yield with the application of nicosulfuron + tembotrione. The yield average difference of the herbicide treatments and the unweeded control showed an increase of 27.66 and 34.59% in the grain yield of the corn hybrids, Formula TL® and SYN 7B28, respectively.  相似文献   
338.
Pulp and paper industries face serious environmental challenges, especially with regard to the conservation of water resources. Chemical thermal mechanical pulping (CTMP) is a process of pulping that combines chemical and mechanical pulping. This reduces the volume of water used in the process. But on the other hand, CTMP generates an effluent with high concentration of organic matter and is difficult to treat. This study evaluated the efficiency in the combination of physicochemical pretreatment by coagulation-flocculation-sedimentation (CFS) process and advanced oxidation process (AOP) by Fenton in sequence to treat CTMP effluent of a Brazilian industry. At first, the best treatment conditions for this type of effluent were determined. To evaluate the efficiency, pH, chemical oxygen demand, biochemical oxygen demand, total organic carbon, lignin contents, color, total phenolic contents, turbidity, and solids were measured before and after treatment. The acute toxicity on Daphnia magna was also determined. The treatment with CFS showed better results in the removal of solids and Fenton in the removal of recalcitrant compounds, such as lignin, demonstrating the need to use them in sequence. Combining CFS and Fenton to treat CTMP effluent allowed to achieve a removal efficiency of 95% for TOC, 61% for COD, and 76% for lignin contents.  相似文献   
339.
The different organic matter fractions of residues significantly impact the degradability of organic material in composting windrows. Based on that, this study aimed to find out the organic matter fractions that most impact the breakdown rate during composting, besides proposing models to estimate the solids reductions in sheep bedding composting windrows. To that end, 24 sheep beddings from different locations and varied composition were composted so as to ensure the representativeness of the sample. The models found for reduction in total (TS) and volatile (VS) solids as a function of compostable organic matter (COM) and organic matter resistant to composting (OMRC) were not significant. Lignin had correlation coefficients of ?0.6, ?0.89, and ?0.84 in relation to temperature, TS reduction, and VS reduction, respectively. The hemicellulose:lignin ratio was the parameter most correlated with temperature (0.69), TS reduction (0.91), VS reduction (0.92), and nitrogen (0.5), which led to more significant predictive models. It can be concluded that the hemicellulose:lignin ratio is the parameter that most impacts the breakdown of organic matter and nitrogen losses in sheep bedding composting windrows.  相似文献   
340.
The tomato (Solanum lycopersicum L.) cultivar Micro‐Tom (MT) is widely used in physiological studies, but the effects of nitrate ( ) and ammonium ( ) ratios ( : ratios) and, in particular, the effects of the accompanying ions in sources are unknown. To determine whether the accompanying ions in sources influence toxicity, the effects of : ratios on the physiology, electrolyte leakage index, nutrition, and dry weight were studied using hydroponics. The sources were ammonium chloride (NH4Cl) or ammonium sulfate [(NH4)2SO4], and five : ratios were used: 100 : 0, 75 : 25, 50 : 50, 25 : 75, and 0 : 100. The source was calcium nitrate [Ca(NO3)2], and the nitrogen (N) concentration was 15 mmol L?1. The results indicate that NH4Cl or (NH4)2SO4 can be used in studies on toxicity because the accompanying ions did not influence the tomato plants. In addition, : ratios of 100 : 0 and 75 : 25 resulted in the highest dry weight of tomato plants, whereas ratios of 25 : 75 or 0 : 100 were toxic.  相似文献   
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