全文获取类型
收费全文 | 297篇 |
免费 | 34篇 |
专业分类
林业 | 9篇 |
农学 | 4篇 |
基础科学 | 1篇 |
67篇 | |
综合类 | 15篇 |
农作物 | 11篇 |
水产渔业 | 26篇 |
畜牧兽医 | 131篇 |
园艺 | 10篇 |
植物保护 | 57篇 |
出版年
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 23篇 |
2018年 | 16篇 |
2017年 | 21篇 |
2016年 | 23篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 12篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
排序方式: 共有331条查询结果,搜索用时 15 毫秒
311.
Alfonso Rodriguez-Alvaro Elisa M Gonzalez-Alonso-Alegre Maria Delclaux-Real del Asua Eva Martinez-Nevado Covadonga Talavera-Ca?ete 《Journal of zoo and wildlife medicine》2005,36(2):336-339
Likely because of trauma, an adult alpaca (Lama pacos) sustained a corneal perforation with a prolapsed iris. Because of the severity of the lesion, a pedicle conjunctival graft was performed. The structural integrity of the cornea was reestablished, and 10 mo postoperatively, the affected eye appeared to have good vision and only a small corneal scar remained. 相似文献
312.
Pharmacokinetics and milk penetration of ibafloxacin after intravenous administration to lactating goats
下载免费PDF全文
![点击此处可从《Canadian journal of veterinary research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pedro Marín Carlos M. Crceles Elisa Escudero Emilio Fernndez-Varn 《Canadian journal of veterinary research》2007,71(1):74-76
The pharmacokinetic behavior of ibafloxacin was studied after intravenous administration of a single dose of 15 mg/kg to 6 healthy lactating goats. Plasma concentrations of ibafloxacin were determined by high-performance liquid chromatography with fluorescence detection. The data for concentration versus time could best be described by a 2-compartment model. The mean plasma ibafloxacin clearance (and standard error) was 1.05 (0.10) L/h x kg. The mean steady-state volume of distribution was 1.65 (0.42) L/kg. The mean elimination half-life was 3.76 (0.30) h. Ibafloxacin penetration from the blood to the milk was poor. The ratio between the areas under the concentration-time curve of milk and plasma was 0.20 (0.01), indicating scant penetration of ibafloxacin into the milk. 相似文献
313.
314.
Géssica Mylena Santana Rêgo Iêda Alana Leite de Souza Gabrielle Avelar Silva Mara Elisa Soares de Oliveira Maria Alves Ferreira 《Forest Pathology》2023,53(2):e12803
Fungi of the Cryphonectriaceae family are globally known to be tree pathogens. In Brazil, several species of Chrysoporthe have been found causing stem and branch cankers in Pleroma (= Tibouchina) spp. Recently, Chrysoporthe puriensis was described as a new species causing stem and branch cankers in Pleroma granulosum, Pleroma candolleanum, and Pleroma heteromallum, all native species of the Melastomataceae family. During an investigation to collect isolates of the Cryphonectriaceae family in an important Brazilian biome, the Atlantic Forest, in Serra do Mar, structures typical of Chrysoporthe species were found in a different host, Pleroma mutabile. Fruiting bodies present in the bark of these trees were collected and isolated. The isolates were submitted on morphological characterization and phylogenetic analyses of the internal transcribed spacer (ITS) and β-tubulin gene regions using Maximum likelihood, Bayesian inference and Maximum parsimony methods. The isolates collected, for this study, were identified as C. puriensis. Pathogenicity tests on seedlings of Pleroma species and Eucalyptus clones revealed C. puriensis can infect and cause canker in these plant species as mortality. The results demonstrate the importance of delimiting the C. puriensis collection range to track its dissemination in other hosts. No host specificity was observed in the inoculation tests, suggesting this is an important finding, the pathogen causes diseases and mortality in several plants of the Atlantic Forest. Additionally, the pathogen can affect others hosts, such as Eucalyptus clones in commercial plantations. 相似文献
315.
Elisa Pellegrini Alessandra Campanella Giacomo Lorenzini Cristina Nali 《Urban Forestry & Urban Greening》2014,13(4):800-805
The wide diffusion of tropospheric ozone is a major environmental problem, in urban area as well as in rural and remote localities. Its increasing man-related levels are connected to severe impacts on human life and welfare, in terms of adverse health effects, damage to manufacts and injury to plants. Biological monitoring is a powerful tool for filling the gap between the causes and the effects of environmental toxins, as bioindication agents assess in an easy-to-detect fashion the effects of pollution on (selected) biota. A project was launched in 2012 to involve some 190 students (ages 11–16) from three schools in Central Italy in biodetection of ozone effects with the hypersensitive plant Nicotiana tabacum Bel-W3. The project also involved teachers and families of the pupils. Results implied the reading of 12,000 biological data (ozone injury on cotyledons) and were fortified by data captured by four automatic analyzers (1300 raw data of hourly means). Biological and chemical data compared favorably and were treated with geostatistical methods; results are exposed in the form of cartographic restitutions. Under the guidance of their teachers, the pupils had several opportunities to practice with many basic and applied study areas and disciplines and were initiated into the scientific method in a simple and absorbing manner. Though primarily an educational exercise, the survey provided sound research elements and the picture of pollution that emerged has increased the knowledge of air quality in the area. Biomonitoring is confirmed to be a powerful tool to involve young people in environmental topics. 相似文献
316.
Elisa Dal Maso Jonathan Cocking Lucio Montecchio 《Urban Forestry & Urban Greening》2014,13(4):697-703
Ash dieback, caused by Hymenoscyphus pseudoalbidus Queloz et al. (anamorph Chalara fraxinea Kowalski), has emerged as a critical disease in urban areas and in the forests of many European countries. This study was conducted to evaluate six fungicides for their potential to control the disease. In vitro assays with different concentrations of the products against five different strains of the pathogen, illustrated that thiabendazole, propiconazole and allicin exhibited lower median lethal doses, procloraz completely killed half of the samples at higher concentrations, whereas copper sulphate and potassium phosphite were totally ineffective. Subsequently, the antifungal activities of the best three compounds were investigated in planta against H. pseudoalbidus by trunk injection. The rate of necroses development following artificial inoculation of 24 F. excelsior was significantly slowed down in the growing season by the treatment with thiabendazole and allicin. In the phenological phase and climatic conditions tested, and with the chosen formulation and injection method, propiconazole injections were impracticable. The results of this study, along with some technical suggestions for application in the field, support the idea of using organic and chemical endotherapic products to combat ash dieback symptoms in Fraxinus spp., with the safe and very low impact method of trunk injection. 相似文献
317.
Pablo del Monte-Luna Daniel Lluch-Belda Elisa Serviere-Zaragoza Roberto Carmona Héctor Reyes-Bonilla David Aurioles-Gamboa José Luis Castro-Aguirre Sergio A. Guzmán del Próo Oscar Trujillo-Millán & Barry W. Brook 《Fish and Fisheries》2007,8(2):107-122
In recent years, more than 130 extinctions have been estimated to have occurred in the marine realm. Here we review this body of evidence and show that this figure may actually be overestimated by as much as 50%. We argue that previous estimates have not fully taken into account critical uncertainties such as naturally variable geographical distributions, and have misinterpreted documentary evidence. However, current evidence indicates that some sharks, rays and reef‐associated species, although not necessarily geographically restricted, are particularly vulnerable to anthropogenic impacts and now occur in very low numbers. Overestimating extinctions is of concern because it could reduce confidence in the credibility of the ‘extinct’ category in threatened species lists and, ultimately, be used to question the integrity of conservation and management policies. We suggest that when integrating future checklists of marine extinct species, there needs to be a more rigorous use of the terminology of extinction, and participation by specialists in each of the particular taxonomic groups involved. 相似文献
318.
Martha Elena Dominguez-Hernandez Rosalba Zepeda-Bautista Elisa Dominguez-Hernandez María del Carmen Valderrama-Bravo Luis Manuel Hernández-Simón 《Archives of Agronomy and Soil Science》2020,66(3):370-385
ABSTRACTAgro-industrial activities such as livestock production and maize processing generate large amounts of waste that can pollute the environment if not treated. To reduce the environmental impact of such wastes, the use of nejayote and ovine manure as fertilizers in maize production was evaluated in terms of yield (GY), energy efficiency (EE) and benefit-to-cost ratio (BCR), during 2015 and 2016. A factorial experiment was designed combining nejayote (0, 75 and 150 m3 ha?1) with manure (0, 25 and 50 Mg ha?1), those treatments were compared with a chemical fertilizer treatment (120N–60P–30K); treatments were done in three replicates. Nejayote-manure fertilizers were characterized physical and chemically. Inputs and outputs used/obtained during the production cycle were registered in terms of their energy equivalents and economic value. At the end of each cycle GY, EE and BCR were calculated. Results showed that nejayote-manure mixtures were 19% more energy efficient and produced a yield 12% greater than chemical fertilization (P = 0.001), thus generating a BCR of 6.3 (P = 0.023). Organic fertilizers were useful as waste treatments and produced greater benefits than chemical fertilizers. Additionally, the water recovered from nejayote was enough to provide a 7.5 or 15 mm of gross irrigation during the crop cycle. 相似文献
319.
Elisa Pellegrini Giacomo Lorenzini Cristina Nali 《Water, air, and soil pollution》2007,181(1-4):401-408
A unique, record-breaking, killer heat wave occurred across several European countries during the first two weeks of August 2003. As weather conditions which characterize heat waves are highly conductive to tropospheric ozone formation and persistence, this is a contributing factor which should be regarded as a major stressor for biota. Hourly ozone means were captured between 1 and 15 August 2003 with automatic analysers in nine stations in Tuscany, distributed into six Districts. Compared to historical ozone reference climatology, daily maxima of 2003 were systematically higher by a factor of about 1.5, with differences which approached three times standard deviation. At the end of the period, cumulated ozone exposure over the threshold of 40 ppb (AOT40) was 4,750 ppb h in 2003, vs 2,200 ppb h of the historical series; such a difference was four times the standard deviation of the long-term series. Biological data are also enclosed in the present study, in the form of analysis of the ratio between above ground biomass produced by NC-S and NC-R clones of white clover when exposed to ambient air. Standardised samplings were performed on a monthly basis, and a significant difference between the two data sets was observed between summer 2003 and the historical series. The close correlation of high-ozone episode with increased temperature (as a consequence of increased solar radiation) suggests that, if climate change were to result in warmer summers in Europe, more frequent exceedances of dangerous ozone thresholds would be expected at the current emission levels. 相似文献
320.
Fábio L. Cruz Elisa B. de Carvalho Eduardo M. Ramos Luciano J. Pereira Márcio G. Zangeronimo 《Journal of animal physiology and animal nutrition》2021,105(3):442-451
The objective was to conduct a systematic review to evaluate the effects of dietary supplementation with beta-adrenergic agonists on calpains and calpastatin activity in bovine muscle and changes in meat tenderness. A survey was conducted in June 2019 on Science Direct, Web of Science, Scopus, PubMed and Capes Periodicals, using four keyword combinations: agonist and calpain and cattle; agonist and calpain and bovine; agonist and calpain and heifers; agonist and calpain and steers. Thirteen studies were selected, 54% concluded that supplementation with beta-adrenergic agonists increases calpastatin activity, 23% observed increase in their gene expression and 23% reported no effect on activity or expression of this enzyme. Nine studies evaluated the influence of beta-adrenergic agonists supplementation on meat texture and all found an increase in shear force values. There is strong evidence that beta-adrenergic agonists may increase calpastatin activity in the muscle, causing damage to meat tenderness. 相似文献