全文获取类型
收费全文 | 598篇 |
免费 | 41篇 |
专业分类
林业 | 50篇 |
农学 | 27篇 |
153篇 | |
综合类 | 33篇 |
农作物 | 32篇 |
水产渔业 | 24篇 |
畜牧兽医 | 258篇 |
园艺 | 14篇 |
植物保护 | 48篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 21篇 |
2020年 | 29篇 |
2019年 | 24篇 |
2018年 | 24篇 |
2017年 | 32篇 |
2016年 | 27篇 |
2015年 | 30篇 |
2014年 | 24篇 |
2013年 | 50篇 |
2012年 | 50篇 |
2011年 | 36篇 |
2010年 | 28篇 |
2009年 | 20篇 |
2008年 | 40篇 |
2007年 | 32篇 |
2006年 | 28篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1970年 | 3篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有639条查询结果,搜索用时 224 毫秒
101.
The average amount of precipitation in spring and summer 2010 and 2011 coupled with relatively high temperatures caused massive Fusarium spp. infection of maize and yield losses in southern Poland. In order to examine the cause of this disease outbreak, Fusarium spp. were isolated and fungal strains were identified based on morphological characters and species-specific PCR assays. A total of 200 maize samples were processed, resulting in the obtention of 71 strains, which belonged to five Fusarium species, F. poae being the predominant one (74.56%). Other isolates were identified as F. graminearum, F. oxysporum, F. verticillioides and F. proliferatum. PCR-based detection of mycotoxin-synthesis-pathway genes was also used to determine the potential of the analyzed strains to produce trichothecenes (DON and NIV) and fumonisins (FUM). Only 14 isolates revealed the potential to produce DON (11 strains) and FUM (3 strains). HPLC analyses of grain samples revealed the presence of DON only – other mycotoxins were not detected. Moreover, 57.1% of potentially mycotoxin-producing isolates indicated the toxicity in a biological test. 相似文献
102.
Many different fungi grow indoors as mold in the presence of moisture. Some of these fungi can cause allergic or toxic reactions, while a few may cause infections in susceptible individuals. A comprehensive treatment of this complex topic would take volumes. Therefore many groups search for alternative management strategies of these fungi. It has been tested if the growth of nine fungi (Alternaria alternata, Botrytis cinerea, Cladosporium herbarum, Fusarium culmorum, F. solani, F. verticillioides, Mucor sp., Penicillium sp. and Trichoderma sp.) which are common in interior buildings could be inhibited by mixing lignin into wall plaster. In maltextract agar lignin concentrations above 10 % inhibited mould growth except for Penicillium sp. However, none of the mould species showed and degradation of lignin. Further investigations on a lignin-plaster-agar, which contained only plaster as nutrient and had a high pH at 8, showed no inhibition on the tested fungi (Alternaria alternata, Fusarium verticillioides, Mucor sp., Trichoderma sp. and Penicillium sp.) at concentrations up to 5 %. Higher lignin concentrations lead to insufficient quality of building materials, e. g. cracking. Furthermore the color of the building materials turned from greyish-white in an exotherm reaction into brown, become not any more suitable for construction purposed. 相似文献
103.
Bodi D Fry H Schafft H Lahrssen-Wiederholt M Preiss-Weigert A 《Journal of agricultural and food chemistry》2012,60(28):6946-6952
Maduramicin is a coccidiostat authorized as feed additive in the European Union for chickens and turkeys for fattening but not for laying hens, considering the risk of residues in eggs. The unavoidable cross-contamination of non-target feed with coccidiostats is regulated by Commission Directive 2009/8/EC and resulting carry-over in food by Commission Regulation (EC) No. 124/2009. To verify the compliance of the maximum levels for maduramicin in feed (50 μg/kg) and eggs (2 μg/kg), the carry-over from feed into eggs was investigated. Diets containing 10, 30, and 50 μg of maduramicin/kg of feed were fed to laying hens. Feed, egg white, and yolk were analyzed by LC-MS/MS. Maduramicin residues were only detected in in egg yolk. Feeding the 10 μg/kg maduramicin diet resulted in maduramicin concentrations up to 2.5 μg/kg in whole eggs, already exceeding the maximum level. A carry-over rate of 8% maduramicin from feed into eggs was calculated. 相似文献
104.
FS Hanschen N Brüggemann A Brodehl I Mewis M Schreiner S Rohn LW Kroh 《Journal of agricultural and food chemistry》2012,60(31):7735-7745
Glucosinolates, present in Brassica vegetables, are thought to contribute to human health prevention because of their enzymatically induced breakdown products, primarily isothiocyanates (ITCs). ITCs are reactive substances that readily react with nucleophilic (food) compounds. The reactivity of allyl-ITC and 4-(methylsulfinyl)butyl-ITC (sulforaphane) toward thiol and amino groups of cysteine and lysine derivatives was studied in buffered model systems as well as broccoli sprouts. The thiol group is the preferred reaction site, and it was demonstrated that even endogenously released sulforaphane is able to react very fast with cysteine in broccoli sprouts. Amino groups reacted slower and only under basic conditions. However, great differences in the reactivity between the different amino compounds were revealed. The aliphatic allylamine reacted very fast with allyl-ITC, forming N,N'-diallylthiourea, a compound identified as a main thermal degradation product of allyl-ITC. 相似文献
105.
Juan Mario Sanz‐Penella Jos Moiss Laparra Yolanda Sanz Monika Haros 《Cereal Chemistry》2012,89(5):223-229
The aim of this investigation was to study the influence of different bran proportions and particle sizes, addition of fungal phytase, and α‐amylase addition on bread quality and phytate levels, and how these treatments affect availability of iron to intestinal epithelial (Caco‐2) cells. Potential mineral contributions to dietary reference intakes and phytate‐to‐mineral molar ratios were also evaluated. Wheat bran supplementation significantly affected bread quality. Smaller bran particle size affected crumb firmness negatively, whereas the use of α‐amylase, in some cases in combination with phytase, could improve technological bread quality. The use of phytase in the formulation significantly reduced the level of phytates, and phytate hydrolysis also led to smaller bran particle size. Increasing the bran proportion used in the bread formulation increased the iron concentration in bread samples by 18.9%. Phytase addition proved to be a useful strategy to improve iron dialyzability; however, incomplete dephytinization still had an inhibitory effect on iron uptake, with the exception of samples formulated with 10% bran. The inhibitory effect of phytate could be predicted from the values of the phytate‐to‐iron ratios. Reduction of particle size did not improve iron availability or uptake by Caco‐2 cells. 相似文献
106.
107.
Anand P Rajakumar D Jeraud M Felix AJ Balasubramanian T 《Pakistan journal of biological sciences: PJBS》2011,14(3):219-225
The aim of the present study is to investigate the effects of oral administration of taurine on endogenous glutathione peroxidase (GPx) and Glutathione Reductase (GR) activities and reduced glutathione (GSH) level in normal rats. Normal saline (Group I) or 5% taurine in normal saline was administered in dose of 50 mg (Group II), 250 mg (Group III) or 500 mg kg(-1) of body weight (Group IV) through intragastric intubation for 60 days. GPx and GR enzyme activities and GSH and taurine levels were determined in liver, heart, stomach, kidney and plasma of normal Wistar rats. GPx activity showed an increase in liver, heart, stomach and plasma. GR activity increased in kidney and decreased in liver and plasma. GSH levels increased in liver, stomach and decreased in kidney. Liver showed an increase and heart, stomach and kidney a decrease in taurine level in taurine administered rats when compared to control rats. The results varied from organ to organ and the observed variations among organs might be related to their respective enzymatic, non-enzymatic antioxidant potential and its functions. From the present study it may be concluded that long term oral administration of taurine affects GPx, GR and GSH levels in normal rats. 相似文献
108.
Dandrieux JR Timm K Roosje PJ Welle M Howard J Brühschwein A Francey T 《Journal of the American Animal Hospital Association》2011,47(2):117-121
A 7 mo old female English springer spaniel was presented with diarrhea, vomiting, apathy, and hyperthermia. Further examinations revealed generalized lymphadenomegaly consistent with sterile neutrophilic-macrophagic lymphadenitis and pulmonary involvement. Subcutaneous nodules developed one day after presentation. Histology was consistent with sterile idiopathic nodular panniculitis and vasculitis. No infectious organism was isolated. The dog responded to prednisolone, but relapsed during medication tapering. Cyclosporine had to be added to control the disease. No further relapse had occurred 98 wk after the first presentation. This is an unusual presentation of a systemic sterile neutrophilic-macrophagic lymphadenitis with nodular panniculitis and vasculitis associated with gastrointestinal and pulmonary signs. 相似文献
109.
110.