全文获取类型
收费全文 | 610篇 |
免费 | 57篇 |
专业分类
林业 | 28篇 |
农学 | 4篇 |
基础科学 | 2篇 |
149篇 | |
综合类 | 34篇 |
农作物 | 32篇 |
水产渔业 | 62篇 |
畜牧兽医 | 303篇 |
园艺 | 14篇 |
植物保护 | 39篇 |
出版年
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 30篇 |
2020年 | 31篇 |
2019年 | 23篇 |
2018年 | 32篇 |
2017年 | 31篇 |
2016年 | 28篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 53篇 |
2012年 | 41篇 |
2011年 | 53篇 |
2010年 | 30篇 |
2009年 | 22篇 |
2008年 | 30篇 |
2007年 | 51篇 |
2006年 | 26篇 |
2005年 | 30篇 |
2004年 | 25篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1980年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1947年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有667条查询结果,搜索用时 939 毫秒
91.
92.
Francesca Marazzi Elena Ficara Riccardo Fornaroli Valeria Mezzanotte 《Water, air, and soil pollution》2017,228(2):68
This paper discusses the possibility of including the culturing of microalgae within a conventional wastewater treatment sequence by growing them on the blackwater (BW) from biosolid dewatering to produce biomass to feed the anaerobic digester. Two photobioreactors were used: a 12 L plexiglas column for indoor, lab-scale tests and a 85 L plexiglas column for outdoor culturing. Microalgae (Chlorella sp. and Scenedesmus sp.) could easily grow on the tested blackwater. The average specific growth rate in indoor and outdoor batch tests was satisfactory, ranging between 0.14 and 0.16 day?1. During a continuous test performed under outdoor conditions from May to November, in which the off-gas from the combined heat and power unit was used as the CO2 source, an average biomass production of 50 mgTSS L?1 day?1 was obtained. However, statistical analyses confirmed that microalgal growth was affected by environmental conditions (temperature and season) and that it was negatively correlated with the occurrence of nitrification. Finally, the biochemical methane potential of the algal biomass was slightly higher than that from waste sludge (208 mLCH4 gVS?1 vs. 190 mLCH4 gVS?1). 相似文献
93.
Shesh Kumari Wilfrida Decraemer Francesca De Luca 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(2):243-250
Populations of Xiphinema brevicollum occurring in the Czech Republic were described morphologically and molecularly. Published species-specific primer set BL18
and BV3 was used to amplify three populations of X. brevicollum from the Czech Republic. These primers were tested against 9 species of Xiphinema and 11 species of Longidorus. Amplification was also observed for X. inaequale, X. italiae and X. lambertii. Three additional markers, mitochondrial cytochrome c oxidase subunit 1, ribosomal D2/D3 expansion segment of the 28S gene
and 18S gene, were amplified and sequenced for X. brevicollum, X. inaequale and X. lambertii belonging to X. americanum-group. Comparison of cox1 sequences of X. brevicollum from the Czech Republic with X. taylori from the Slovak Republic (accession number AM086702) suggested that these populations represent the same species. 相似文献
94.
Sudmant PH Kitzman JO Antonacci F Alkan C Malig M Tsalenko A Sampas N Bruhn L Shendure J; Genomes Project Eichler EE 《Science (New York, N.Y.)》2010,330(6004):641-646
Copy number variants affect both disease and normal phenotypic variation, but those lying within heavily duplicated, highly identical sequence have been difficult to assay. By analyzing short-read mapping depth for 159 human genomes, we demonstrated accurate estimation of absolute copy number for duplications as small as 1.9 kilobase pairs, ranging from 0 to 48 copies. We identified 4.1 million "singly unique nucleotide" positions informative in distinguishing specific copies and used them to genotype the copy and content of specific paralogs within highly duplicated gene families. These data identify human-specific expansions in genes associated with brain development, reveal extensive population genetic diversity, and detect signatures consistent with gene conversion in the human species. Our approach makes ~1000 genes accessible to genetic studies of disease association. 相似文献
95.
Philippe Berny Francesca Caloni Siska Croubels Magda Sachana Virginie Vandenbroucke Franca Davanzo Raimon Guitart 《Veterinary journal (London, England : 1997)》2010,183(3):255-259
This is the second in a series of three review articles on animal poisoning in Europe and focuses on cases in pet animals and horses in five European countries (Belgium, France, Greece, Italy and Spain) reported over the last decade. In the participating countries, dogs were the most commonly poisoned species, particularly younger animals. The majority of cases in companion animals resulted from exposure to insecticides, although rodenticides (especially anticoagulants and strychnine) posed a significant risk. In all five countries, horses and cats appeared to be more susceptible to plant toxins. Intoxications with herbicides, metals, household products and drugs for veterinary and human use were reported sporadically. The review demonstrates the importance of increased awareness so as to minimise poisoning episodes and emphasises the need to establish a European system for the recording of poisoning data. 相似文献
96.
M Gil N Kontoudakis E González M Esteruelas F Fort JM Canals F Zamora 《Journal of agricultural and food chemistry》2012,60(32):7988-8001
The aim of this paper was to study how maturity and maceration length affect color, phenolic compounds, polysaccharides, and sensorial quality of Cabernet Sauvignon and Tempranillo wines at three stages of grape ripening. Ripeness increased color extractability, phenolic compounds, and polysaccharide concentrations. Moreover, the proanthocyanidin mean degree of polymerization (mDP) and the percentage of prodelphinidins also increased with maturity, whereas the percentage of galloylation decreased. In general, wines from riper grapes contain higher proportions of skin proanthocyanidins. Color and anthocyanin concentration decreased when the maceration was longer, whereas polysaccharide and proanthocyanidin concentrations did the opposite. It was also detected that the mDP and the percentage of prodelphinidins decreased when the maceration was extended, whereas the percentage of galloylation increased. These data seem to indicate that proanthocyanidin extraction from seeds is clearly increased throughout the maceration time. 相似文献
97.
Custódio L Escapa AL Fernandes E Fajardo A Aligué R Alberício F Neng N Nogueira JM Romano A 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(1):78-84
This work aimed to evaluate the phytochemical content and to determine the antioxidant and cytotoxic activities of methanol
extracts of the carob tree (Ceratonia siliqua L.) germ flour. The extracts were rich in phenolic compounds, had considerable antioxidant activity, and reduced the viability
of cervical (HeLa) cancer cells. The chemical content and the biological activities of the extracts were significantly affected
by gender and cultivar. Female cultivar Galhosa had the highest levels of phenolic compounds, and the highest antioxidant
activity. Extracts from the hermaphrodite trees and from the female cultivars Galhosa and Costela/Canela exhibited the highest
cytotoxic activity. The most abundant compound was theophylline. The phenolic content was correlated to both antioxidant and
cytotoxic activities. Our findings provide new knowledge about the health implications of consuming food supplemented with
carob germ flour. 相似文献
98.
González-de-la-Vara Mdel R Valdez RA Lemus-Ramirez V Vázquez-Chagoyán JC Villa-Godoy A Romano MC 《Canadian journal of veterinary research》2011,75(3):216-221
Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle. 相似文献
99.
Castoria R Mannina L Durán-Patrón R Maffei F Sobolev AP De Felice DV Pinedo-Rivilla C Ritieni A Ferracane R Wright SA 《Journal of agricultural and food chemistry》2011,59(21):11571-11578
The infection of stored apples by the fungus Penicillium expansum causes the contamination of fruits and fruit-derived products with the mycotoxin patulin, which is a major issue in food safety. Fungal attack can be prevented by beneficial microorganisms, so-called biocontrol agents. Previous time-course thin layer chromatography analyses showed that the aerobic incubation of patulin with the biocontrol yeast Rhodosporidium kratochvilovae strain LS11 leads to the disappearance of the mycotoxin spot and the parallel emergence of two new spots, one of which disappears over time. In this work, we analyzed the biodegradation of patulin effected by LS11 through HPLC. The more stable of the two compounds was purified and characterized by nuclear magnetic resonance as desoxypatulinic acid, whose formation was also quantitated in patulin degradation experiments. After R. kratochvilovae LS11 had been incubated in the presence of (13)C-labeled patulin, label was traced to desoxypatulinic acid, thus proving that this compound derives from the metabolization of patulin by the yeast. Desoxypatulinic acid was much less toxic than patulin to human lymphocytes and, in contrast to patulin, did not react in vitro with the thiol-bearing tripeptide glutathione. The lower toxicity of desoxypatulinic acid is proposed to be a consequence of the hydrolysis of the lactone ring and the loss of functional groups that react with thiol groups. The formation of desoxypatulinic acid from patulin represents a novel biodegradation pathway that is also a detoxification process. 相似文献
100.
Ballabio C Uberti F Di Lorenzo C Brandolini A Penas E Restani P 《Journal of agricultural and food chemistry》2011,59(24):12969-12974
Celiac disease is a food intolerance triggered by the ingestion of gluten-containing cereals; the only therapy is a strict gluten-free diet for life. In recent years, amaranth flour has received considerable attention as an interesting source for the formulation of gluten-free products due to its high nutritional value and low content of prolamins, the toxic proteins for celiacs. The aim of this study was to characterize 40 amaranth varieties using both SDS-PAGE/immunoblotting and ELISA to assess their possible tolerance by celiac subjects. All of the amaranth samples studied showed similar binding affinities for both specific anti-gliadin antibodies and human IgAs. In most amaranth grains, the content of gluten-like proteins measured by ELISA was <20 ppm. The molecular characterization of amaranth proteins suggests that amaranth is safe for celiacs to consume. It is recommended that the most suitable amaranth varieties are those having the lowest content of proteins cross-reacting with anti-gliadin antibodies. 相似文献