全文获取类型
收费全文 | 449篇 |
免费 | 29篇 |
专业分类
林业 | 31篇 |
农学 | 22篇 |
130篇 | |
综合类 | 19篇 |
农作物 | 24篇 |
水产渔业 | 11篇 |
畜牧兽医 | 194篇 |
园艺 | 11篇 |
植物保护 | 36篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 18篇 |
2020年 | 22篇 |
2019年 | 15篇 |
2018年 | 14篇 |
2017年 | 22篇 |
2016年 | 23篇 |
2015年 | 24篇 |
2014年 | 21篇 |
2013年 | 41篇 |
2012年 | 43篇 |
2011年 | 28篇 |
2010年 | 25篇 |
2009年 | 15篇 |
2008年 | 31篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有478条查询结果,搜索用时 828 毫秒
401.
Humeny A Kislinger T Becker CM Pischetsrieder M 《Journal of agricultural and food chemistry》2002,50(7):2153-2160
The nonenzymatic reaction between reducing sugars and proteins, known as the Maillard reaction, has received increased recognition from nutritional science and medical research. The development of new analytical techniques for the detection of protein-bound Maillard products is therefore crucial. In this study, we applied peptide mapping by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to investigate the formation of structurally specific Maillard products on glycated lysozyme (AGE-lysozyme), produced upon incubation with D-glucose. In parallel, we synthesized N(epsilon)-(carboxymethyl)lysine-modified lysozyme (CML-lysozyme) and N(epsilon)-(carboxyethyl)lysine-modified lysozyme, two well-described glycation products, as model substances. 3-Deoxyglucosone-modified lysozyme and methylglyoxal-modified lysozyme were prepared as examples of glycation products incubated with dicarbonyl compounds. We were able to detect specific modifications on AGE-lysozyme, which were assigned to CML, imidazolone A, and the Amadori product. 相似文献
402.
Linseed is able to accumulate considerably high concentrations of Cd in generative organs, the dietary critical value of 0.3 μg Cd/g seed often being exceeded. Differences between genotypes of linseed in this respect, however, have been observed but the underlying mechanisms responsible for these differences are unknown. The aim of the present work was to identify these mechanisms by studying the Cd accumulation of the linseed genotypes Antares and McGregor which differ in their ability to accumulate Cd in the seeds. Cultivar Antares is a high and cv. McGregor a low Cd accumulator which was confirmed in a pot experiment. It was found that the differences between these genotypes were Cd-specific and were caused neither by single seed weight nor by Cd translocation into the shoot. The distribution pattern of Cd within mature capsules between the pericarp and the seeds differed from that of Ca which was used as a phloem-immobile reference ion. From these results we conclude that Cd was translocated from the pericarp into the seeds via the phloem. This conclusion was supported by direct Cd determination in collected phloem sap from linseed stems. As sources of seed-Cd we identified the pericarps of capsules and the leaves. The genotype differences concerning the Cd concentrations in the seeds may be explained in terms of differences in phloem translocation of Cd. 相似文献
403.
High rates of cattle slurry application induce NO
inf3
sup-
leaching from grassland soils. Therefore, field and lysimeter trials were conducted at Gumpenstein (Austria) to determine the residual effect of various rates of cattle slurry on microbial biomass, N mineralization, activities of soil enzymes, root densities, and N leaching in a grassland soil profile (Orthic Luvisol, sandy silt, pH 6.6). The cattle slurry applications corresponded to rates of 0, 96, 240, and 480 kg N ha-1. N leaching was estimated in the lysimeter trial from 1981 to 1991. At a depth of 0.50 m, N leaching was elevated in the plot with the highest slurry application. In October 1991, deeper soil layers (0–10, 10–20, 20–30, 30–40, and 40–50 cm) from control and slurry-amended plots (480 kg N ha-1) were investigated. Soil biological properties decreased with soil depth. N mineralization, nitrification, and enzymes involved in N cycling (protease, deaminase, and urease) were enhanced significantly (P<0.05) at all soil depths of the slurry-amended grassland. High rates of cattle slurry application reduced the weight of root dry matter and changed the root distribution in the different soil layers. In the slurry-amended plots the roots were mainly located in the topsoil (0–10 cm). As a result of this study, low root densities and high N mineralization rates are held to be the main reasons for NO
inf3
sup-
leaching after heavy slurry applications on grassland. 相似文献
404.
Tauer A Elss S Frischmann M Tellez P Pischetsrieder M 《Journal of agricultural and food chemistry》2004,52(7):2042-2046
The production of alcoholic beverages such as Tequila, Mezcal, whiskey, or beer includes the fermentation of a mash containing Maillard reaction products. Because excessive heating of the mash can lead to complications during the following fermentation step, the impact of Maillard products on the metabolism of Saccharomyces cerevisiae was investigated. For this purpose, fermentation was carried out in a model system in the presence and absence of Maillard reaction products and formation of ethanol served as a marker for the progression of fermentation. We found that increasing amounts of Maillard products reduced the formation of ethanol up to 80%. This effect was dependent on the pH value during the Maillard reaction, reaction time, as well as the carbohydrate and amino acid component used for the generation of Maillard reaction products. Another important factor is the pH value during fermentation: The inhibitory effect of Maillard products was not detectable at a pH of 4 and increased with higher pH-values. These findings might be of relevance for the production of above-mentioned beverages. 相似文献
405.
406.
Willamson JA Kaelble M Chisholm A 《Journal of the American Animal Hospital Association》2011,47(2):112-116
A 9 yr old spayed female cocker spaniel presented for an acute onset of weakness. Rhabdomyolysis and myoglobinuria were found 36 hr after presentation. The dog was managed for several electrolyte and mineral abnormalities and rhabdomyolysis-induced acute renal failure. The diagnosis of idiopathic necrotizing myopathy was determined by histopathology and by the exclusion of underlying infectious agents and metabolic defects. The dog recovered completely from the acute crisis and acute renal failure. 相似文献
407.
408.
409.
410.
Monika Frielinghaus Heinz Petelkau Heike Schäfer Klaus Seidel Lothar Müller 《Archives of Agronomy and Soil Science》2013,59(1-2):19-35
The efficiency and acceptance for erosion and compaction control management is not high and therefore not a guarantee for sustainable land use and soil functionality. The best method for increasing acceptance is a regional soil indicator system combined with an environmental indicator system (McRae et al. 2000). Like the concept of “critical load inputs”; for chemical pollutants, this system would make it possible to quantify the soil state and soil condition for decisions concerning the soil carrying or load capacity. The next step is the assessment of the land use pressure on soil in terms of the soil load capacity and the driving forces for land use. These results may determine the response level required: In a balanced situation, Best Management Practices may help ensure sustainability is maintained, slightly disproportional results suggest additional special agricultural management techniques may be needed, while significant differences may indicate the need for additional land use adjustments or changes in technical management. The indicator system is ideal for application in north‐eastern Germany for all moraine areas and the areas at risk to water and wind erosion and soil compaction. 相似文献