全文获取类型
| 收费全文 | 102篇 |
| 免费 | 2篇 |
专业分类
| 林业 | 15篇 |
| 农学 | 7篇 |
| 基础科学 | 2篇 |
| 26篇 | |
| 综合类 | 2篇 |
| 农作物 | 10篇 |
| 水产渔业 | 6篇 |
| 畜牧兽医 | 27篇 |
| 园艺 | 2篇 |
| 植物保护 | 7篇 |
出版年
| 2024年 | 1篇 |
| 2023年 | 1篇 |
| 2021年 | 4篇 |
| 2020年 | 1篇 |
| 2019年 | 1篇 |
| 2018年 | 7篇 |
| 2017年 | 5篇 |
| 2016年 | 1篇 |
| 2015年 | 3篇 |
| 2014年 | 8篇 |
| 2013年 | 6篇 |
| 2012年 | 7篇 |
| 2011年 | 7篇 |
| 2010年 | 8篇 |
| 2009年 | 5篇 |
| 2008年 | 5篇 |
| 2007年 | 6篇 |
| 2006年 | 1篇 |
| 2005年 | 3篇 |
| 2004年 | 4篇 |
| 2003年 | 3篇 |
| 2002年 | 3篇 |
| 2000年 | 1篇 |
| 1999年 | 2篇 |
| 1998年 | 1篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1994年 | 1篇 |
| 1992年 | 3篇 |
| 1991年 | 1篇 |
| 1987年 | 1篇 |
| 1985年 | 1篇 |
| 1982年 | 1篇 |
排序方式： 共有104条查询结果，搜索用时 15 毫秒
31.
Maurício Emerenciano Gerard Cuzon Miguel Arévalo Gabriela Gaxiola 《Aquaculture Research》2014,45(10):1713-1726
A 45‐day trial was performed to evaluate the effect of biofloc technology (BFT) with or without fresh food (FF) supplementation during pre‐maturation period on Farfantepenaeus duorarum spawning performance, biochemical composition and fatty acid profile of eggs as compared with conventional clear‐water system (CW+FF). Females raised in biofloc and that received FF supplementation (FLOC+FF) achieved better spawning performance in terms of number of eggs per spawn (49 × 103), number of eggs per spawn per g of spawner's body weight (2.1 × 103) and egg size (~275 μm) as compared with CW+FF (23 × 103, 1.1 × 103 and 263 μm respectively), but both treatments did not vary from FLOC (P > 0.05). High spawning activity was also observed in biofloc system as compared with clear‐water system as shown in number of spawns per ablated female (2.2–3.0 versus 0.6) and percentage of females that spawn at least once (80–82 versus 25%). Biochemical composition of eggs presented no significant differences among treatments. FA profile of eggs indicated that high spawning activity performed by females in FLOC+FF treatment was reflected in lower mean levels of EPA, DHA and sum of polyunsaturated fatty acids (n‐3) and (n‐6). The better reproductive performance demonstrated by females raised in biofloc justified the application of this technology in F. duorarum broodstock. 相似文献
32.
Danter Huansi Cachique Henry Ruiz Solsol Marco Antonio García Sanchez Luis Alberto Arévalo López Nete Kodahl 《Genetic Resources and Crop Evolution》2018,65(7):2027-2036
Underutilized crop species have the potential to aid in alleviating some of the challenges faced by the world today; reduced food security and malnutrition, land degradation, and climate change. The incorporation of little-known crops into sustainable agricultural systems provides new developmental opportunities and can increase the resilience of food production systems. However, measures need to be taken to address issues of variation in product quality and access to propagation material. Plukenetia volubilis L. (Euphorbiaceae) is an oleaginous liana native to the Amazon basin. It is of growing economic importance in the food, pharmaceutic, cosmetic and horticultural industries, however, commercial cultivars are lacking and the genetic variation within the species is very high. Furthermore, the majority of landraces of P. volubilis are susceptible to nematodes. In order to attain plants with a consistent quality and yield, vegetative propagation schemes are beneficial. Grafting is an especially favourable technique which enables the selection of pest and disease resistant rootstocks in combination with high-yielding or ornamentally valuable scions. Three different grafting techniques combined with three different systems of protection were tested on P. volubilis and evaluated according to the growth of the scions following grafting. The experiment was carried out under nursery conditions in the San Martín region of Peru, where P. volubilis is commonly cultivated. Regardless of the grafting technique, a 100% survival rate was found for plants covered with a plastic bag following grafting. This result may aid in the further domestication of P. volubilis by providing farmers with access to plant material of consistent quality and allowing the selection of pest resistant rootstocks in combination with high-yielding scions. 相似文献
33.
Arūnas P. Verbyla Joanne De Faveri John D. Wilkie Tom Lewis 《Journal of Agricultural, Biological & Environmental Statistics》2018,23(4):478-508
Modelling response surfaces using tensor cubic smoothing splines is presented for three designed experiments. The aim is to show how the analyses can be carried out using the asreml software in the R environment, and details of the analyses including the code to do so are presented in a tutorial style. The experiments were all run over time and involve an explanatory quantitative treatment variable; one experiment is a field trial which has a spatial component and involves an additional treatment. Thus, in addition to the response surface for the time by explanatory variable, modelling of temporal and, for the third experiment, of temporal and spatial effects at the residual level is required. A linear mixed model is used for analysis, and a mixed model representation of the tensor cubic smoothing spline is described and seamlessly incorporated in the full linear mixed model. The analyses show the flexibility and capacity of asreml for complex modelling.Supplementary materials accompanying this paper appear online. 相似文献
34.
Diego Arán Juan Antelo Sarah Fiol Felipe Macías 《Journal of Soils and Sediments》2018,18(9):2914-2923
Purpose
Phosphorus is an essential element that at high concentrations generates eutrophication of aquatic systems. In this study, we used batch and continuous tests to evaluate the efficiency of a Technosol to retain the phosphorus present (as phosphate) in aqueous samples.Materials and methods
Phosphate sorption on Technosol was studied through batch and continuous experiments. Sorption kinetics and isotherms were investigated at different phosphate loadings and pH. In batch tests, we have determined how the presence of different anions (bicarbonate, sulphate, chloride, chromate and molybdate) affected phosphate retention. In continuous flow systems, phosphate immobilization was assessed as a function of flow rate, pH and Technosol concentration. Finally, the potential reutilization of the column was evaluated using consecutive sorption-desorption cycles.Results and discussion
Phosphate sorption follows a pseudo-second-order kinetics model and a Langmuir isotherm model. The maximum sorption capacity ranged from 7.1 to 18.5 mg g?1, with larger values obtained at the highest pH. The main mechanisms involved in the sorption process were precipitation (as Ca-P minerals) and surface adsorption. In the column experiments, we observed a sorption reduction from 6.19?±?0.06 to 2.37?±?0.06 mg g?1 as the flow rate increased from 1.5 to 5.0 mL min?1. In addition, the retention capacity decreased by 14% when the height of the reactive layer was halved. Finally, the retention capacity of the Technosol spolic silandic recovered well after several sorption-desorption cycles, reaching 40% of the original value after first and second cycles.Conclusions
The material effectively retained phosphate in batch and continuous flow systems. The Technosol spolic silandic is considered an efficient sorbent to remove the excess of phosphate from the soil solution and the aqueous system. This material may be a useful tool to mitigate or minimize two important environmental problems: eutrophication and the scarcity of natural sources of phosphate. The Technosol can thus be recycled as a phosphate-rich amendment and the leachates can be used to produce liquid fertilizer.35.
Humberto González-Rodríguez Roque Gonzalo Ramírez-Lozano Israel Cantú-Silva Marco Vinicio Gómez-Meza Eduardo Estrada-Castillón José Ramón Arévalo 《林业研究》2018,29(5):1307-1314
Studies on litterfall and decomposition provide estimations of decomposition rates of different ecosystems.This is key information to understanding ecosystem dynamics and changes in a scenario of global warming.The objective of this research was to assess litterfall production,the potential deposition of macro and micronutrients through leaf and twig fall as well as macronutrient—use efficiency in three forest ecosystems at different altitudes: a pine forest mixed with deciduous species(S1); a Quercus spp.forest(S2); and,a Tamaulipan thornscrub forest(S3).Total annual litterfall deposition was 594,742 and 533 g m~(-2) for S1,S2 and S3.Leaf litter was higher (68%) than twigs(18%),reproductive structures(8%) or miscellaneous material(6%).Micronutrient leaf deposition was higher for Fe followed by Mn,Zn and Cu.Macronutrient leaf deposition was higher for Ca followed by K,Mg and P.Even though P deposition in leaves and twigs was lower than other macronutrients,its nutrient use efficiency was higher than Ca,Mg or K.Altitude and species composition determine litter and nutrient deposition,with higher values at mid-altitudes(550 m).Altitude is an important factor to consider when analyzing litter production as well as nutrient deposition as shown in this study.Litter production and nutrient deposition are expected to change in a scenario of global warming. 相似文献
36.
Maria Dolores Mingorance Aránzazu Peña Ignacio Guzmán Sabina Rossini Oliva 《Journal of Soils and Sediments》2017,17(5):1301-1309
Purpose
In mine soils, especially from arid or semiarid areas, the use of low-quality water for irrigation is a usual practice. Therefore to fill this gap, different experiments have been carried out to evaluate the effect of compost, pesticide and wastewater on the growth of tomato plants in a mine soil located at an iron extraction area.Materials and methods
Soils proceeded from Alquife mine wastes whose most outstanding characteristics are alkaline conditions, low organic matter and electrical conductivity and high As concentration. The compost of sewage sludge (CSL) used to amend this soil had a slightly acid pH (6.8), EC 3.0?±?0.07 dS m-1 (1/10 ratio, m/V) and 10 % organic carbon (OC) content. Irrigation was performed with distilled water (DW) or wastewater (WW) and two pesticides, the insecticide thiacloprid and the fungicide fenarimol, were applied to the soil. Tomato was grown directly from seeds on each pot. Four treatments with addition of pesticides were considered. For comparison purposes, two additional treatments without pesticides were also included.Results and discussion
Addition of compost of sewage sludge led to a significant and sustained increase of soil OC content and dehydrogenase activity, while irrigation with wastewater had a slight or negligible effect on both properties. The plant species responded negatively to wastewater irrigation when this practice was undertaken with the application of both pesticides. No detectable amounts of thiacloprid, a relatively unstable and polar insecticide, were found in soil. The concentration of fenarimol in soil was higher after amendment with compost, but was not modified by irrigation with wastewater. In tomato shoots, the amounts of both pesticides were inversely correlated with final soil organic carbon, indicating that this soil property is relevant for their plant uptake. Besides, fenarimol concentrations in the soil and the tomato shoots were inversely related (r?=??0.836).Conclusions
Tomato was not able to grow healthy in Alquife mine soil without compost addition. The irrigation with wastewater only reduced plant growth when used in combination with pesticides. Uptake of both pesticides by tomato plants was negligible according to the low bioaccumulation factor values, but was almost doubled for wastewater irrigation. Caution should be taken with the use of treated wastewater, because it may reduce plant growth in tomato that is a species sensitive to salinity.37.
Antimicrobial treatments have become more important for the textile materials especially used in sportswear, activewear, and
casual wear since they can easily be contaminated by perspiration leading to bacterial growth and body odor. In this work,
antimicrobial activity of chitosan in a silica matrix on pretreated wool fabrics was studied. The pretreatment processes were
applied by two different ways (enzymatic and enzymatic+hydrogen peroxide). Afterwards chitosan solutions were applied to the
untreated samples and to the samples that were pretreated by two different ways to give antimicrobial effects. The antimicrobial
activity of wool fabrics treated in various methods was assessed before and after repeated washings (up to 10 cycles) by the
application of standard test method AATCC 147-1998. The morphology of the treated fabrics was investigated by SEM and their
characterizations were made by the FT-IR spectral analysis. Results revealed that pretreatment ways and chitosan application
methods were quite important for adsorption and diffusion of chitosan on wool fabrics and washing stability. From the SEM
images, it was clearly observed that pretreatment processes caused some degradation on the surface of the fiber; but combined
processes were found to be less degradative and more effective. 相似文献
38.
39.
Lamb, beef and cow's milk are common causes of cutaneous adverse food reactions in dogs. The aim of this study was to identify the proteins responsible for cutaneous adverse reactions to these foods. Ten dogs with allergen-specific serum immunoglobulin (Ig)E to lamb, beef and cow's milk were included in the study. These dogs had been diagnosed with cutaneous adverse food reactions by convincing clinical history and food-elimination diet trials followed by challenge exposure. Sera were analysed by enzyme-linked immunosorbent assay with bovine proteins and SDS-PAGE immunoblots with lamb, beef and cow's milk extracts. All the dogs had specific IgE against bovine IgG, and it was the only protein in the cow's milk extract that bound IgE from the sera studied. In the lamb and beef extracts, the major allergens recognized by the specific IgE of most sera had molecular masses between 51 and 58 kDa, which were identified as phosphoglucomutase and the IgG heavy chain. Other IgE-binding proteins with molecular masses of 27, 31, 33, 37 and 42 kDa were also detected with some sera. Our results indicate that bovine IgG is a major allergen in cow's milk and hence it appears to be a source of cross-reactivity with beef and probably with lamb because of the high homology with ovine immunoglobulins. These results are similar to those found for meat allergy in humans. However, this is the first time that phosphoglucomutase has been identified as an important allergen involved in allergic reactions to lamb and beef. 相似文献
40.
Ruiz A Foronda P González JF Guedes A Abreu-Acosta N Molina JM Valladares B 《Veterinary parasitology》2008,154(1-2):137-141
Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is a wide-spread intestinal protozoa of both humans and animals. Although giardiosis in goat is commonly asymptomatic, young kids may bear an enteric disease associated with persistent diarrhoea and delayed weight gain. In the present study we have analysed the occurrence of Giardia in 315 young goat kids (2–6 months old) from Gran Canaria Island (Spain) through visualization of faecal cysts. The identification of genotypes of G. duodenalis among the farms was attained by nested PCR of the triophosphate isomerase (TPI) and single PCR of β-giardin genes and subsequent sequencing. Positive samples were found in 42.2% of the animals and 95.5% of the farms. Goat faecal specimens were positive for only livestock-associated G. duodenalis assemblage E genotype for both TPI and β-giardin genes. The genetic analysis of these two loci revealed the presence of different haplotypes among the farms included in the survey and high homology with homologous genes from cattle and sheep. Altogether, the data presented here provide additional information to the prevalence and genetic characterization of Giardia isolates. The absence of assemblages A and B in this study suggests that zoonotic transmission of Giardia from goats could be of low epidemiological significance, although these findings should be validated in studies including other geographical areas, age groups and larger number of samples. 相似文献