全文获取类型
收费全文 | 1113篇 |
免费 | 87篇 |
国内免费 | 1篇 |
专业分类
林业 | 53篇 |
农学 | 40篇 |
基础科学 | 4篇 |
243篇 | |
综合类 | 62篇 |
农作物 | 52篇 |
水产渔业 | 127篇 |
畜牧兽医 | 530篇 |
园艺 | 22篇 |
植物保护 | 68篇 |
出版年
2024年 | 3篇 |
2023年 | 17篇 |
2022年 | 16篇 |
2021年 | 39篇 |
2020年 | 34篇 |
2019年 | 30篇 |
2018年 | 40篇 |
2017年 | 36篇 |
2016年 | 39篇 |
2015年 | 32篇 |
2014年 | 63篇 |
2013年 | 82篇 |
2012年 | 79篇 |
2011年 | 125篇 |
2010年 | 47篇 |
2009年 | 49篇 |
2008年 | 82篇 |
2007年 | 50篇 |
2006年 | 45篇 |
2005年 | 55篇 |
2004年 | 39篇 |
2003年 | 35篇 |
2002年 | 32篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有1201条查询结果,搜索用时 31 毫秒
991.
Gomez Hector Alonzo Gomez Marques Marcia Ortiz Mayo Borges Cristine Vanz Minatel Igor Otavio Monteiro Gean Charles Ritschel Patricia Silva Zanus Mauro Celso Diamante Marla Silvia Kluge Ricardo Alfredo Lima Giuseppina Pace Pereira 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(2):258-264
Plant Foods for Human Nutrition - Some biogenic amines (BAs) are used as quality markers in grape-derived products. The prolife of 9 BAs was determined in juices and wines elaborated from hybrid... 相似文献
992.
David Sewordor Gaikpa Silvia Koch Franz Joachim Fromme Dörthe Siekmann Tobias Würschum Thomas Miedaner 《Plant Breeding》2020,139(3):508-520
Rye is a multi-purpose cereal crop grown in Central and Eastern Europe as well as in Western Canada. Fusarium head blight (FHB) is one of the diseases that have a severe negative impact on rye, but knowledge about FHB resistance at the genomic level is totally missing in rye. The objective of this study was to elucidate the genetic architecture of FHB resistance in winter rye using genome-wide association (GWA) mapping complemented by genomic prediction (GP) in comparison with marker-assisted selection (MAS). Additionally, plant height and heading stage were analysed. A panel of 465 S1-inbred lines of winter rye was phenotyped in three environments (location–year combinations) for FHB resistance by inoculation with Fusarium culmorum and genotyped with a 15k SNP array. Significant genotypic variation and high heritabilities were found for FHB resistance, heading stage and plant height. FHB did not correlate with heading stage, but was moderately correlated with plant height (r = −.52, p < .001) caused by some susceptible short inbred lines. The GWA scan identified 15 QTL for FHB resistance that jointly explained 74% of the genotypic variance. In addition, we detected 11 QTL for heading stage and 8 QTL for plant height, explaining 26% and 14% of the genotypic variance, respectively. A genome-wide prediction approach resulted in 44% higher prediction abilities than marker-assisted selection for FHB resistance. In conclusion, genomic approaches appear promising to improve and accelerate breeding for complex traits in winter rye. 相似文献
993.
Rodrigo Javier Vargas Silvia Maria Guimarães de Souza Alexandre Melo Kessler & Sueli Regina Baggio 《Aquaculture Research》2008,39(6):657-665
The jundiá (Rhamdia quelen) is a siluriform with great potential for aquaculture in South America. Fish oil is a raw material in diets for fish. However, the fisheries that provide fish oil have reached their limit of sustainability. Thus, the use of alternative sources for this ingredient is primordial. The aim of this study was to evaluate the performance and body composition of the jundiá fed with different sources of the vegetable oils. Jundiá (1.0±0.2 g) were fed for 31 days with five isonitrogenous (37%) and isoenergetic (19 kJ g?1) diets, in which the following oils were added: 50 g kg?1 corn oil (CO), 50 g kg?1 fish oil (FO), 50 g kg?1 linseed oil (LO), 33.4 g kg?1 fish oil and 16.7 g kg?1 linseed oil (1/3LO), 16.7 g kg?1 fish oil and 33.4 g kg?1 linseed oil (2/3LO). The performance did not show differences between treatments. The final fatty acid profile and n‐3/n‐6 ratio of the fish were highly influenced by the diet. Fish‐fed diets with linseed and/or fish oil showed superior n‐3/n‐6 ratios to the minimal recommended by the World Health Organization; whereas fish fed diets with corn oil showed an inferior value. Albeit in the present study the commercial size of fish was not attained, these results show a clear tendency. The desaturation/elongation capacity was evidenced, in this species, for the first time. Linseed oil can be utilized as a substitute for fish oil in diets of jundiá without affecting their performance and for producing good‐quality fish. However, more studies are necessary to confirm these results for commercial size. 相似文献
994.
Lindsay G Ross Carlos A Martinez Palacios & Ernesto J Morales 《Aquaculture Research》2008,39(7):675-683
Aquaculture continues to be the fastest growing animal production industry and this rate of expansion must continue if aquaculture is to satisfy global demand for fish products in the face of dwindling capture fisheries. The relationship between aquaculture and biodiversity is complex, with examples of positive and negative impacts having been reported. To enable this expansion while avoiding negative impacts from introductions of exotic species, the investigation of indigenous species becomes important and worthwhile.This paper establishes the background to development of new species for culture and describes the example of the Mexican silverside Menidia estor, which has for centuries been the principal species in an artesanal fishery in Lake Pátzcuaro, Mexico. The species is geographically isolated and is unique but is now endangered because of a range of factors including overfishing, environmental degradation and introduction of exotic species. Considerable advances have been made recently in developing a closed reproductive cycle, understanding feeding and small‐scale on‐growing technology for the species. Based on this, a Darwin Initiative programme was developed focused on technology transfer to implement small‐scale pilot on‐growing thus helping to conserve the species and to improve livelihoods. This has allowed successful pilot scale development of aquaculture for the species while at the same time addressing the objectives of the international Convention on Biodiversity. 相似文献
995.
Leonardo Bolognesi da Silva Leonardo José Gil Barcellos Rosmari Mezzalira Quevedo Silvia Maria Guimarães de Souza Alexandre de Mello Kessler Luiz Carlos Kreutz Filipe Ritter Jovani Antônio Finco & Alexandra Calliari Bedin 《Aquaculture Research》2008,39(5):542-551
Fish polyculture is based on the assumption that each species has its own feeding niche and may increase the maximum standing crop of a pond by exploring a wider range of available food and ecological niches. In order to identify the better species ratio and to introduce jundia (JN) (Rhamdia quelen Quoy & Gaimard) and Nile tilapia (NT) (Oreochromis niloticus Linnaeus) in to the carp polyculture practiced in South Brazil, a 162‐day experiment was conducted, in 12 250‐m2 earthen ponds (1.2 m deep). Treatment I (T‐I) contained 35% common carp, Cyprinus carpio (L.) (CC); 35% grass carp, Ctenopharyngodon idella Valenciennes (GC); 15% silver carp, Hypophthalmichthys molitrix Valenciennes (SC); and 15% bighead carp, Aristichthys nobilis Richardson (BC). Treatment II (T‐II) consisted of three ponds stocked at the following ratio: 17.5% CC, 35% GC, 15% SC, 15% BC and 17.5% JN. Treatment III (T‐III) consisted of three ponds with 35% CC, 35% GC, 7.5% SC, 7.5% BC and 15% NT. Treatment IV (T‐IV) consisted of three ponds with 17.5% CC, 35% GC, 7.5% SC, 7.5% BC%, 17.5% JN and 15% NT. No significant correlation was found between the treatments with different species ratio and water quality parameters. The final weight of different species, in different treatments, was statistically different. The major result was the clear positive effect on growth parameters observed by the introduction of JN and/or NT in to the carp polyculture. The yield per hectare was 2083.33±183 kg ha?1 for polyculture with carp species; 2476.67±139.88 kg ha?1 following the introduction of JN only; 2801.67±111.42 kg ha?1 for isolated introduction of NT; and 2506.67±422.31 kg ha?1 for simultaneous introduction of JN and NT. The introduction of JN and/or NT had a positive effect on growth parameters when compared with carp‐only polyculture. The reduction in CC ratio also had a positive effect on growth parameters. 相似文献
996.
Valentina Moccia Alessandro Sammarco Silvia Ferro Laura Cavicchioli Valentina Zappulli 《Veterinary and comparative oncology》2023,21(1):36-44
Extracellular vesicles (EVs) are cell-derived membrane-bound vesicles involved in many biological processes such as tumour progression. For years, ultracentrifugation (UC) has been considered the gold standard for EV isolation but limited purity and integrity allowed the diffusion of alternative techniques. In this study, EVs were isolated from a canine mammary tumour cell line using UC and size exclusion chromatography (SEC) and analysed for size and concentration by nanoparticle tracking analysis (NTA) and for protein expression by western blot (WB). EV autocrine effect on cell proliferation, migration and invasiveness was then evaluated in vitro. In all samples, particles were in the EV size range (50–1000 nm), with a higher concentration in UC than in SEC samples (1011 and 1010 particles/ml respectively), and expressed EV markers (Alix, CD9). Functional assays did not show statistically significant difference among conditions, but EV treatment slightly increased cell proliferation and invasiveness and treatment with SEC-isolated EVs slightly enhanced cell migration compared to UC-isolated EVs. In conclusion, the main differences between the two isolation techniques are the quantity of the final EV-product and slight differences on EV functionality, which should be further explored to better highlight the real autocrine effect of tumoral EVs. 相似文献
997.
Stephanie E. Martinez Yufei Chen Emmanuel A. Ho Steven A. Martinez Neal M. Davies 《Canadian journal of veterinary research》2015,79(3):241-249
Multicomponent nutraceuticals are becoming increasingly popular treatments or adjunctive therapies for osteoarthritis in veterinary medicine despite lack of evidence of efficacy for many products. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of a commercially available C-phycocyanin-based nutraceutical and select constituent ingredients in an in-vitro model of canine osteoarthritis. Normal canine articular chondrocytes were used in an in-vitro model of osteoarthritis. Inflammatory conditions were induced using interleukin-1β. The nutraceutical preparation as a whole, its individual constituents, as well as carprofen were evaluated at concentrations of 0 to 250 μg/mL for reduction of the following inflammatory mediators and indicators of catabolism of the extracellular matrix: prostaglandin E2 (PGE2), tumor necrosis factor-α (TFN-α), interleukin-6 (IL-6), metalloproteinase-3 (MMP-3), nitric oxide, and sulfated glycosaminoglycans (sGAGs). Validated, commercially available assay kits were used for quantitation of inflammatory mediators. The antioxidant capacities, as well as cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) inhibitory activities of the whole nutraceutical preparation and select constituents, were also assessed using validated commercially available assay kits. The antioxidant capacity of the nutraceutical and constituents was concentration-dependent. The nutraceutical and constituents appear to display anti-inflammatory activity primarily through the inhibition of COX-2. The nutraceutical displayed similar strength to carprofen in reducing TNF-α, IL-6, MMP-3, nitric oxide, and sGAGs at select concentration ranges. The C-phycocyanin (CPC)-based nutraceutical and constituents may be able to mediate 3 primary pathogenic mechanisms of osteoarthritis: inflammation, chondral degeneration, and oxidative stress in vitro. The nutraceutical may be clinically useful in veterinary medicine and its efficacy should be further investigated in vivo. 相似文献
998.
Effectiveness of a combined (4% chlorhexidine digluconate shampoo and solution) protocol in MRS and non‐MRS canine superficial pyoderma: a randomized,blinded, antibiotic‐controlled study
下载免费PDF全文
![点击此处可从《Veterinary dermatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
999.
The use of contrast‐enhanced ultrasonography for the detection of active renal hemorrhage in a dog with spontaneous kidney rupture resulting in hemoperitoneum
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
1000.
Summary Variation in the capacity to regenerate shoots and morphogenetic potential were investigated by cyclic culture and regeneration of Nicotiana tabacum var. BEL W3. Explants were excised from different shoots formed by the same callus line. Differences in the organogenetic in vitro response among regenerated plantlets was observed in two subsequent regenerate generations. A progressive decrease of the regenerative capacity was observed across callus line generations. 相似文献