全文获取类型
| 收费全文 | 306篇 |
| 免费 | 10篇 |
专业分类
| 林业 | 54篇 |
| 农学 | 10篇 |
| 58篇 | |
| 综合类 | 20篇 |
| 农作物 | 22篇 |
| 水产渔业 | 32篇 |
| 畜牧兽医 | 95篇 |
| 园艺 | 5篇 |
| 植物保护 | 20篇 |
出版年
| 2023年 | 1篇 |
| 2022年 | 7篇 |
| 2021年 | 9篇 |
| 2020年 | 7篇 |
| 2019年 | 9篇 |
| 2018年 | 7篇 |
| 2017年 | 13篇 |
| 2016年 | 8篇 |
| 2015年 | 13篇 |
| 2014年 | 19篇 |
| 2013年 | 19篇 |
| 2012年 | 33篇 |
| 2011年 | 34篇 |
| 2010年 | 19篇 |
| 2009年 | 20篇 |
| 2008年 | 17篇 |
| 2007年 | 20篇 |
| 2006年 | 13篇 |
| 2005年 | 7篇 |
| 2004年 | 6篇 |
| 2003年 | 8篇 |
| 2002年 | 10篇 |
| 2000年 | 2篇 |
| 1999年 | 3篇 |
| 1998年 | 2篇 |
| 1994年 | 1篇 |
| 1993年 | 4篇 |
| 1992年 | 1篇 |
| 1991年 | 1篇 |
| 1982年 | 1篇 |
| 1979年 | 1篇 |
| 1972年 | 1篇 |
排序方式： 共有316条查询结果，搜索用时 125 毫秒
131.
132.
Julio L. Lancelotti Luciana M. Pozzi Pablo M. Yorio María C. Diéguez Miguel A. Pascual 《水产资源保护:海洋与淡水生态系统》2010,20(1):1-8
- 1. Conflicts between habitat use and conservation are inherent to the management of wetlands. A major challenge for their management is to preserve habitat while addressing the demands from multiple users. In southern Patagonia (Argentina), a growing aquaculture activity based on rainbow trout introductions in shallow lakes is generating concerns about the effects on the waterbird fauna, including some endemic species.
- 2. Generalized linear models (GLM) were used to analyse data on the endemic hooded grebe (Podiceps gallardoi) collected over a diverse set of lakes to: (1) build presence‐absence models as a function of environmental variables; (2) assess current and potential overlap with trout aquaculture; (3) explore the power of alternative lake assignment algorithms based on habitat variables to segregate critical habitat and aquaculture activities; and (4) explore the correlation between the probability of grebe presence and their abundance in given lakes.
- 3. Hooded grebe presence is clearly correlated with macrophyte cover, lake area, and water conductivity. Medium size lakes, with a combination of emerging macrophytes, adjacent to open water areas had the highest probability of both hooded grebe presence and abundance.
- 4. Different lake allocation scenarios are identified that could grant significant protection to hooded grebes without substantial losses for trout producers. The a priori probability to hold hooded grebe, assigned by the model based on lake characteristics, provides a tool that can be used by managing authorities to derive precautionary management rules to regulate aquaculture and to preserve primary hooded grebe habitat. Copyright © 2009 John Wiley & Sons, Ltd.
133.
de Lucas JJ Navarro JL Rubio S Vignolo PE Asis VC González F Rodríguez C 《Veterinary journal (London, England : 1997)》2008,175(1):136-138
The pharmacokinetic behaviour of enrofloxacin in greater rheas was investigated after intramuscular (IM) administration of 15 mg/kg. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high performance liquid chromatography. Enrofloxacin peak plasma concentration (C(max)=3.30+/-0.90 microg/mL) was reached at 24.17+/-9.17 min. The terminal half-life (t(1/2lambda)) and area under the curve (AUC) were 2.85+/-0.54 h and 4.18+/-0.69 microg h/mL, respectively. The AUC and C(max) for ciprofloxacin were 0.25+/-0.06 microg/mL and 0.66+/-0.16 microg h/mL, respectively. Taking into account the values obtained for the efficacy indices, an IM dose of 15 mg/kg of enrofloxacin would appear to be adequate for treating infections caused by highly susceptible bacteria (MIC(90)<0.03 microg/mL) in greater rheas. 相似文献
134.
Marcos Paulo Gonçalves de Rezende Julio Cesar de Souza Paulo Luiz Souza Carneiro Riccardo Bozzi Rodrigo Jose Delgado Jardim Carlos Henrique Mendes Malhado 《Tropical animal health and production》2018,50(5):1033-1040
Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal’s size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding. 相似文献
135.
Leonardo José Assis de Barros Marcelo de Andrade Ferreira Julio César Vieira de Oliveira Djalma Cordeiro dos Santos Juana Catarina Cariri Chagas Adryanne Marjorie Souza Vitor Alves Aghata Elins Moreira da Silva Wandemberg Rocha Freitas 《Tropical animal health and production》2018,50(1):149-154
This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets. 相似文献
136.
Jorge Vergara-Galicia Rolffy Ortiz-Andrade Julio Rivera-Leyva Patricia Castillo-España Rafael Villalobos-Molina Maximiliano Ibarra-Barajas Itzell Gallardo-Ortiz Samuel Estrada-Soto 《Fitoterapia》2010,81(5):350-357
RMELanc-induced relaxation in aortic rings precontracted with NE, 5-HT and KCl. It also reduced NE-induced transient contraction in Ca2+-free solution and inhibited contraction induced by increasing external calcium. Nevertheless, the vasorelaxant effect of RMELanc was not reduced by ODQ, 1-alprenolol, TEA, glibenclamide, and 2-AP. Oral administration of 100 mg/kg of RMELanc exhibited a significant decrease in systolic and diastolic blood pressures in SHR rats. HPLC analysis allowed us to detect the presence of 2,7-dihydroxy-3,4,9-trimethoxyphenantrene (1), which induced a significant relaxation effect. Therefore, our results suggest that RMELanc induces vasorelaxant and antihypertensive effects by blockade of Ca2+ channels. 相似文献
137.
Julio Avila Elisa Acosta María-del-Valle Machargo María-Francisca Arteaga Eduardo Gallego Haridian Cañete José-Javier García-Pérez Pablo Martín-Vasallo 《Journal of Autoimmune Diseases》2008,5(1):3
Background
Systemic vasculitides constitute a heterogeneous group of diseases of autoimmunological origin characterized by inflammation of blood vessels and antibodies that react against autoantigens in a process that ultimately affects blood vessel walls. An important number of these patients present kidney disease. An endeavour of this area of research is the identification of autoantigens involved in these diseases. Accordingly, we used serum from a patient suffering from a microscopic polyangiitis, P-ANCA positive, manifesting a clinically atypical renal necrotizing glomerulonephritis and interstitial nephropathy for the identification of autoantigens; we also determined the prevalence of corresponding autoantibodies in other vasculitides, diabetic microangiopathy and in general population.Methods
The patient's serum was used as a probe for the immunoscreening method SEREX to screen a human brain cDNA expression library.Results
Four positive clones were isolated and sequenced. Clones Jos002 code for protein HDAC5, Jos014 for TFC4, Jos107 for RTF1, and Jos313 for POLDIP3 polymerase. The four proteins are of nuclear localization. None of them had been reported as autoantigen. Recombinant proteins were synthesised and checked as antigens by western blot with different sera from controls and patients affected with other vasculitides and diabetic microangiopathy as well. Only the serum from the patient origin of this study recognized all recombinant proteins.Conclusion
We identify four nuclear proteins, HDAC5, TFC4, RTF1 and POLDIP3 polymerase as new autoantigens that could be used as markers in the diagnosis of subfamilies in immune diseases, although we cannot determine the role of these proteins in the aetiopathogenic process.138.
139.
Julio Campo Juan F. Gallardo Guillermina Hernández 《European Journal of Forest Research》2014,133(1):121-129
We compared the N and P contents of the main labile components of nutrient cycles in three different forest ecosystems [a tropical evergreen forest (TEF); a tropical dry forest (TDF); and a Mediterranean temperate forest (MTF)] with low P supply. A mass-balance approach was used to estimate mean residence times for organic matter, N and P in the forest floor, and to examine the flexibility of N and P intra-system cycling in the three forest ecosystems. For this purpose, we combined published values of N and P in foliage, litterfall, forest floor litter and mineral soils in these three forest ecosystems. The results of our analysis were consistent with the widely held belief that the N content of leaves (both green and senescent) and litter increases with increasing temperatures. In contrast, the data did not support the hypothesis that leaf P content decreases with increasing temperatures and precipitation: leaf and litterfall P contents were higher in both tropical forests than they were in the temperate forest. The TEF had the highest P content of the three forests studied. The mass-balance analysis indicated that although P mineralization in the TDF can run ahead of litter decomposition stoichiometry when P is in short supply, flexibility is much reduced or absent in the TEF and the MTF. Our analysis provides additional evidence of the importance of climatic factors in forest ecosystem processes and highlights the role of flexibility in ecosystem nutrient cycling, especially for P in ecosystems with a limited P supply. 相似文献
140.
M. Carmen Ferreras Camino González-Lanza Valentín Pérez Miguel Fuertes Julio Benavides Mercedes Mezo Marta González-Warleta Javier Giráldez Ana María Martínez-Ibeas Laetitia Delgado Miguel Fernández M. Yolanda Manga-González 《Veterinary parasitology》2014,199(3-4):268-271
The prevalence and aetiology of natural paramphistomosis was investigated in cattle slaughtered in the Castilla y León region (Spain) over a 3 year-period. The overall prevalence of positive animals was 6.20%. The parasite burden per animal ranged from 8 to 8005 (median = 144) and the ruminal atrium had the highest parasite burden whereas the ruminal dorsal sac the lowest. The prevalence and parasite burden increased with age while these parameters were lower in cattle under intensive management. Calicophoron daubneyi was the only Paramphistomidae species identified using morphoanatomical, histological and molecular methods in the studied animals. 相似文献