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31.
Curcumin-containing nanocapsule powder formulations have not been used in ruminant feed to date, despite the fact that curcumin is known to be a functional food additive. The objective of this study was to determine whether ethyl polymethacrylate (Eudragit L-100) nanocapsules loaded with curcumin (N-CU) would improve health and growth of lambs. Thirty-two male Lacaune lambs (body weight [BW] = 16 ± 0.99 kg; 45 d of age) were randomly assigned to 1 of 4 treatments: T0, T1, T2 and T4, representing supplementation of curcumin at 0, 1, 2, and 4 mg/kg concentrate, respectively. The animals in each treatment were allocated in 4 pens of 2 lambs each (8 lambs per treatment). The experiment lasted 17 d, with samples and measurements collected on d 0, 7, 12, and 17. The T2 lambs had greater average daily gain than T0 lambs. Regression analysis showed that the ideal dose of N-CU to enhance weight gain was 1.89 mg/kg concentrate. There were significant interactions (P < 0.05) between treatments × time for hematological variables, particularly for increases in erythrocytes (T2) and reductions in counts of leukocytes, neutrophils, and lymphocytes in T1 and T2. There were significant interactions between treatment × time for total protein, globulin, urea, and triglyceride levels. Stimulation of the antioxidant system was also observed. There were increased levels of non-protein thiols (NPSH), as well as increased activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in the supplemented animals. Levels of reactive oxygen species (ROS) were lower in the serum of supplemented lambs. In general, the 4 mg/kg dose had no positive effects on growth or health. This was an unexpected result, given the known properties of curcumin. Taken together, these findings suggest that addition of low concentrations of nanoencapsulated curcumin (T1 and T2) in lamb feed improves health, minimizing oxidative stress and generates anti-inflammatory effects that may have contributed indirectly to greater weight gain. Nanocapsules potentiate the effects of curcumin and may emerge as a new tool in animal nutrition.  相似文献   
32.
In Zacatecas, Mexico, four plants are operating to extract Ag, Au, and Hg using CaS2O3 solution from surface soil containing tailings from the amalgamation method used during 1550–1900. The metal ions extracted are cemented by scrap Cu wires. Hg is separated by evaporation from the cemented amalgam and Ag and Au are obtained from the residue. A part of the soil to be leached was separated and leached as in the industrial process. Only 121 ppm of Hg was freed from 168 ppm of extractable Hg. About a half of the remaining Hg in the soil evaporated during 18 months. This confirms that the Hg in the soil is metallic. Pb and As are also freed in the same process. It is estimated that 13 000–34 000 t of Hg had been discarded in the extraction of Ag.  相似文献   
33.
The sorption of N-[[(4,6-dimethoxypyrimidin-2-yl)amino]carbonyl]-1-methyl-4-(2-methyl-2H-tetrazole-5-yl)1H-pyrazole-5-sulfonamide (AZS) on an iron oxide, iron(III)-humate, and an Fe3+-saturated clay was studied using a batch equilibrium method. Generally, 20 mg of each colloid was equilibrated with 20 mL of AZS solution (1.5-12.7 microM). The sorption on iron-montmorillonite and iron oxide was rapid, and the equilibrium was attained within 1.5 and 5 h, respectively. In the case of Fe-saturated humic acid the equilibrium time was 20 h. After equilibration, the phases were centrifuged (19000g, 15 min) and the supernatant was sampled and analyzed by HPLC. The values of Freundlich constants indicate that iron oxide (Kads = 199.5) shows the highest sorptive capacity toward AZS, followed by iron(III)-clay (Kads = 146.6) and iron(III)-humate (Kads = 108.2). With elapsing time, AZS degradation was observed in all colloidal suspensions. Iron-humate (t(1/2) = 136 h) is most effective in promoting AZS degradation, followed by iron oxide (t(1/2) = 204 h) and iron-clay (t(1/2) = 385 h). The metabolites 2-amino-4,6-dimethoxypyrimidine and 1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H-pyrazole-5-sulfonamide, arising from a hydrolytic cleavage of the sulfonylurea bridge, were the only byproducts observed. A Fourier transform infrared study suggests that the sorption of AZS on iron-clay involves the protonation of one of the two basic pyrimidine nitrogens induced by the acidic water surrounding the saturating Fe3+ ions. Instead, the formation of a six-membered chelated complex favors the sorption of AZS on iron oxide.  相似文献   
34.
Nonylphenol (NP) is used as an antioxidant and plasticizer in some plastic products. After the discovery of its endocrine-disrupting potential, concern over human exposure to this chemical has increased. Recently, a group in Germany estimated the average daily intake of NP from food (7.5 microg/day), excluding water. In the present study, NP, octylphenol (OP), and their respective ethoxylates (1-5) were measured in spring water bottled in three different types of plastic (HDPE, PET, and PVC). NP was present in water from HDPE and PVC containers, at 180 and 300 ng/L respectively, which represent 4.8% and 8% of the value calculated by the German group assuming a consumption of 2 L of water per day. OP was found in water from HDPE extracts in lower amounts, 12 ng/L, and neither the NP- nor the OP-ethoxylates were detected in any of the samples. Attempts to measure these compounds in tap water were unsuccessful, probably because reaction with residual chlorine results in the formation of chlorinated byproducts. Migration of NP from HDPE containers to a milk surrogate was also evaluated; results indicate that the amounts of NP leaching into milk might be similar to those in bottled water.  相似文献   
35.
Azimsulfuron sorption--desorption on soil   总被引:11,自引:0,他引:11  
The sorption and desorption of the herbicide azimsulfuron, N-[[(4-dimethoxypyrimidin-2-yl)amino]carbonyl]1-methyl-4-(2-methyl-2H-tetrazole-5-yl)1H-pyrazole-5-sulfonamide, were studied using five soils. Sorption isotherms conformed to the Freundlich equation. It was found that pH is the main factor influencing the sorption and that the sorption on soils was negatively correlated with pH. The highest level of sorption was measured on soils with low pH and high organic carbon content. Moreover, inorganic soil colloids, for example, smectite clay minerals and iron oxides, contributed to the sorption of azimsulfuron. Desorption was hysteretic on soils with high organic and inorganic colloid contents.  相似文献   
36.
Adsorption and desorption of triasulfuron by soil   总被引:10,自引:0,他引:10  
The adsorption and desorption of the herbicide triasulfuron [2-(2-chloroethoxy)-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide] by three soils, soil organic matter (H(+) and Ca(2+)-saturated), and an amorphous iron oxide were studied. Adsorption isotherms conformed to the Freundlich equation. It was found that pH is the main factor influencing the adsorption in all of the systems. Indeed, the adsorption on soils was negatively correlated with pH. The highest level of adsorption was measured on soils with low pH and high organic carbon content. Moreover, it was found that humic acid is more effective in the adsorption compared with calcium humate (the pH values of the suspensions being 3.5 and 6, respectively). Experiments on amorphous iron oxide confirmed the pH dependence. Desorption was hysteretic on soils having high organic carbon content.  相似文献   
37.
The origin and authenticity of feed for laying hens is an important and fraud-susceptible aspect in the production of organic eggs. Chemical fingerprinting in combination with chemometric methods is increasingly used in conjunction with administrative controls to verify and safeguard the authenticity of food commodities. On the basis of fatty acid fingerprinting data of 36 organic and 60 conventional feeds, we have developed a chemometric classification model to discriminate between organic and conventional chicken feed. A two-factor partial least squares-discriminant analysis (PLS-DA) model was developed using 70% of the original data. External validation of the model with the remaining 30% of the data showed that all of the organic feeds and 90% of the conventional feeds (18 of 20) were correctly identified by the model. These results indicate that the PLS-DA model developed in this study could be routinely used to verify the identity of unknown or suspicious feed for laying hens.  相似文献   
38.

Accurate estimation of biomass in natural vegetation sites remains a challenge. Modeling biomass growth and production in Cerrado areas is crucial to understanding the vegetation succession process, especially regarding the changes in biomass accumulation over time. Thus, our objective was to model the growth and production of woody aboveground biomass (living and total) in a cerrado stricto sensu monitored for 27 years after implementing management systems. As expected, the basal area (with a diameter taken at 30 cm from the ground level) is the most important predictor variable and showed a higher correlation with the biomass stocks and allowed accurate and consistent estimates of these accumulated stocks over time. Future estimates of biomass production, generated from growth models that estimate production as a function of parameters observed at previous ages, indicate that maximum stocks of living (25.86?±?0.15 Mg ha?1 [mean?±?standard deviation]) and total aboveground biomass (26.11?±?0.15 Mg ha?1) are expected for a period between 28 and 30 years after the implementation of the management systems, with maximum mean annual increment between 23 and 27 years. Furthermore, the systems of equations obtained simulated reductions up to 30% of biomass after the occurrence of a forest fire at 23 years. Thus, our study can be useful for the decision-making process and developing public policies and strategies for managing and conserving natural resources in the Cerrado biome.

  相似文献   
39.
Journal of Pest Science - It has become clear that omnivorous predators can induce plant defences that affect the performance and host plant choice of herbivores. They are also known to induce the...  相似文献   
40.
To enhance early detection of West Nile virus (WNV) transmission, an integrated ecological surveillance system was implemented in Catalonia (north‐eastern Spain) from 2007 to 2011. This system incorporated passive and active equine surveillance, periodical testing of chicken sentinels in wetland areas, serosurveillance wild birds and testing of adult mosquitoes. Samples from 298 equines, 100 sentinel chickens, 1086 wild birds and 39 599 mosquitoes were analysed. During these 5 years, no acute WNV infection was detected in humans or domestic animal populations in Catalonia. WNV was not detected in mosquitoes either. Nevertheless, several seroconversions in resident and migrant wild birds indicate that local WNV or other closely related flaviviruses transmission was occurring among bird populations. These data indicate that bird and mosquito surveillance can detect otherwise silent transmission of flaviviruses and give some insights regarding possible avian hosts and vectors in a European setting.  相似文献   
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