全文获取类型
收费全文 | 343篇 |
免费 | 30篇 |
专业分类
林业 | 32篇 |
农学 | 11篇 |
基础科学 | 2篇 |
87篇 | |
综合类 | 15篇 |
农作物 | 19篇 |
水产渔业 | 63篇 |
畜牧兽医 | 107篇 |
园艺 | 13篇 |
植物保护 | 24篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 18篇 |
2020年 | 25篇 |
2019年 | 12篇 |
2018年 | 17篇 |
2017年 | 12篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 13篇 |
2013年 | 27篇 |
2012年 | 22篇 |
2011年 | 36篇 |
2010年 | 22篇 |
2009年 | 13篇 |
2008年 | 23篇 |
2007年 | 14篇 |
2006年 | 21篇 |
2005年 | 8篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1981年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有373条查询结果,搜索用时 15 毫秒
21.
22.
Lorenzo C Pardo F Zalacain A Alonso GL Salinas MR 《Journal of agricultural and food chemistry》2005,53(19):7609-7616
The red grapes co-winemaking effect on phenolic fraction and wine color has been studied for the first time, where Monastrell was comacerated and cofermentated with Cabernet Sauvignon and Merlot. Changes in the relative abundance of anthocyanins were observed as well as hyperchromic shifts at 530 and 620 nm; these effects remain constant after aging. Co-winemaking also favored copigmentation, giving way to more stable anthocyanins and facilitating their polymerization. With regard to color evolution, the mixture of Monastrell with Merlot grapes was more appropriate than with Cabernet Sauvignon for aging wines in oak barrels. The extent of copigmentation was more important in young wines than in aged wines. This is mainly due to the self-anthocyanin monomer reactions in the case of young wines, whereas in aged wines copigmentation is mainly due to the reaction between the anthocyanins and other polyphenolic cofactors. Discriminant analysis showed the possibility of differentiating wines according to the aging time and the type of wine, with color parameters (color intensity, OD 620 nm, and OD 520 nm) being the most important discrimination variables in the first case and petunidin-3-glucoside and peonidin-3-glucoside contents in the second case. 相似文献
23.
24.
Llorenç Grau-Roma Lorenzo Fraile Joaquim Segalés 《Veterinary journal (London, England : 1997)》2011,187(1):23-32
Post-weaning multisystemic wasting syndrome (PMWS) emerged as a significant disease affecting pig production in the 1990s although the causal agent, porcine circovirus type 2 (PCV2), and the disease itself, had existed in swine for many years prior to this. The important multifactorial ‘triggers’ of PMWS include the immune and infection status of the sow, the timing of PCV2 infection, variations in the virulence of PCV2, co-infections, immune modulation as well as host genetics and management factors. In terms of diagnosis, histopathological examination and the detection of PCV2 within lymphoid tissue remains the ‘gold standard’ as quantitative PCR techniques are currently not specific or sensitive enough. The recent commercial availability of PCV2 vaccines provides an excellent tool for reducing the impact of PMWS and other porcine circovirus-related diseases. This review assesses recent advances in the epidemiology, diagnosis and control of PMWS. 相似文献
25.
Season appears to influence the physiology of bottlenose dolphins (Tursiops truncatus). From 2000 to 2005, blood parameters of three captive bottlenose dolphins housed in northern Italy were examined to determine if seasonal variation was present. Seasonal variation was observed in the male dolphins, with both males exhibiting aminotransferase levels that were higher in autumn and lower in winter. Mean serum creatinine levels were higher during summer and lower during autumn in the adult male, and mean lactate dehydrogenase higher during summer and lower during spring in the juvenile male. Both males exhibited red blood cell counts and hemoglobin levels that were higher during autumn and lower during summer. This study contributes to the knowledge of baseline hematologic and biochemical values based on seasonality in bottlenose dolphins. 相似文献
26.
Cocchi M Foca G Lucisano M Marchetti A Pagani MA Tassi L Ulrici A 《Journal of agricultural and food chemistry》2004,52(5):1062-1067
Different kinds of cereal flours submitted to various technological treatments were classified on the basis of their mid-infrared spectra by pattern recognition techniques. Classification in the wavelet domain was achieved by using the wavelet packet transform for efficient pattern recognition (WPTER) algorithm, which allowed singling out the most discriminant spectral regions. Principal component analysis (PCA) on the selected features showed an effective clustering of the analyzed flours. Satisfactory classification models were obtained both on training and test samples. Furthermore, mixtures of varying composition of the studied flours were distributed in the PCA space according to their composition. 相似文献
27.
28.
Iglesias MT De Lorenzo C Del Carmen Polo M Martín-Alvarez PJ Pueyo E 《Journal of agricultural and food chemistry》2004,52(1):84-89
With the aim of finding methods that could constitute a solid alternative to melissopalynological and physicochemical analyses to determine the botanical origin (floral or honeydew) of honeys, the free amino acid content of 46 honey samples has been determined. The honeys were collected in a small geographic area of approximately 2000 km(2) in central Spain. Twenty-seven honey samples were classified as floral and 19 as honeydew according to their palynological and physicochemical analyses. The resulting data have been subjected to different multivariant analysis techniques. One hundred percent of honey samples have been correctly classified into either the floral or the honeydew groups, according to their content in glutamic acid and tryptophan. It is concluded that free amino acids are good indicators of the botanical origin of honeys, saving time compared with more tedious analyses. 相似文献
29.
30.