全文获取类型
收费全文 | 205篇 |
免费 | 14篇 |
专业分类
林业 | 5篇 |
农学 | 3篇 |
53篇 | |
综合类 | 18篇 |
农作物 | 7篇 |
水产渔业 | 22篇 |
畜牧兽医 | 90篇 |
园艺 | 7篇 |
植物保护 | 14篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 19篇 |
2011年 | 17篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 17篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有219条查询结果,搜索用时 15 毫秒
151.
Pre-harvest foliar applications to increase fruit calcium (Ca) content and reduce bitter pit incidence, is a standard practice world wide. We re-evaluated the effectiveness of early season applications versus late applications of calcium nitrate (Ca(NO3)2) to reduce bitter pit in ‘Golden Delicious,’ under the present environmental conditions of the Western Cape, South Africa. Two periods of efficient uptake of external Ca were identified, viz., during cell division and the last few weeks before harvest. Foliar Ca applications during mid season (from 40 d after full bloom) were more effective in increasing fruit Ca content and reducing bitter pit incidence, than later applications. Thus, it is important to apply the bulk of the Ca(NO3)2 during the first few weeks after cell division to maximize the Ca content of ‘Golden Delicious’ apples. 相似文献
152.
Inge M Krijger Jan BWJ Cornelissen Henk J Wisselink Bastiaan G Meerburg 《Acta veterinaria Scandinavica》2014,56(1)
Background
The prevalence of Toxoplasma gondii in common moles, Talpa europaea, was investigated in order to determine whether moles can serve as an indicator species for T. gondii infections in livestock.Findings
In total, 86 moles were caught from 25 different sites in the Netherlands. Five different trapping habitats were distinguished: pasture, garden, forest, roadside, and recreation area. No positive samples (brain cysts) were found during microscopic detection (n = 70). Using the Latex Agglutination Test (LAT), sera of 70 moles were examined, whereby no sample reacted with T. gondii antigen. Real Time-PCR tests on brain tissue showed 2 positive samples (2.3%).Conclusions
Because of the low number of positives in our study, the use of the common mole as an indicator species for livestock infections is currently not recommended.Electronic supplementary material
The online version of this article (doi:10.1186/s13028-014-0048-0) contains supplementary material, which is available to authorized users. 相似文献153.
154.
A. Jafari P. A. Finke J. Vande Wauw S. Ayoubi H. Khademi 《European Journal of Soil Science》2012,63(2):284-298
The main objectives of this study were to compare binary logistic regression as an indirect approach and multinomial logistic regression as a direct approach to produce soil class maps in the Zarand region of southeast Iran. With indirect prediction, the occurrence of relevant diagnostic horizons was first mapped, and subsequently, various maps were combined for a pixel‐wise classification by combining the presence or absence of diagnostic horizons. In direct prediction, the dependent variable was the great group itself, so the probability distribution of the great soil groups was directly predicted. Among the predictors, the geomorphology map was identified as an important tool for digital soil mapping approaches as it helped to increase the accuracy. The results of prediction showed larger mean probability values for each great soil group in the areas actually covered by the great soil groups compared with other areas, indicating the reliability of the prediction. In most predictions, the global purity was slightly better than the actual purity for the models; however, both models provided poor predictions for Haplocambids and Calcigypsids. The results showed that soils with better prediction were those much influenced by topographical and geomorphological characteristics and soils with very poor accuracy of prediction were only slightly influenced by topographical and geomorphological characteristics. An advantage of the indirect method is that it gives insight into the causes of errors in prediction at the scale of diagnostic horizons, which helps in the selection of better covariates. 相似文献
155.
Inge Bjerks 《Acta veterinaria Scandinavica》1990,31(4):423-432
Central nervous system lesions were studied by light microscopy in 43 farmed mink, aged 5 months to 2 1/2 years, with spontaneous encephalitozoonosis and showing cataractous eye changes. Lesions were found in the brain and spinal cord of all animals examined but were generally mild and chronic. The lesions were consistent with those previously described in spontaneous encephalitozoonosis in other carnivores. Parasites in parasitophorous vacuoles and free or phagocytosed in necrotic and granulomatous lesions were demonstrated in animals aged 5 months to 1 year. The occurrence of arterial lesions of the polyarteritis nodosa type found in the youngest animals probably indicates fetal infection. In animals aged 1 1/2 and 2 1/2 years active lesions were usually lacking and the changes were characterized by arterial sclerosis, sometimes with aneurysmal formations, small perivascular lympho-plasmacytic cuffings and focal gliosis. 相似文献
156.
Benders NA Dyer J Wijnberg ID Shirazi-Beechey SP van der Kolk JH 《American journal of veterinary research》2005,66(1):93-99
OBJECTIVE: To confirm whether the plasma glucose concentration curve obtained during oral glucose tolerance tests (OGTTs) in horses with equine motor neuron disease (EMND) is decreased, compared with that obtained in clinically normal horses, and determine whether that decrease is a result of defective glucose metabolism or intestinal glucose transport dysfunction. ANIMALS: 8 horses with EMND and 44 matched control horses. PROCEDURE: Electromyography and OGTTs were performed in all 8 affected horses and 10 control horses. Intravenous GTTs (IVGTTs) were performed in 6 affected horses and another 11 control horses. The activity and levels of jejunal luminal membrane glucose transporter (Na+ / glucose cotransporter isoform 1 [SGLT1]) were measured in 2 affected horses and 23 control horses. RESULTS: In horses with EMND, generalized neuropathy was detected via quantitative electromyography; the mean increase in plasma glucose concentration during the OGTT was significantly decreased, compared with the value in control horses. During the IVGTT the mean increase in plasma glucose concentration was significantly lower than that of control horses. The activity and levels of SGLT1 in 2 affected horses were similar to those of control horses. Diagnosis of EMND was confirmed postmortem in all affected horses. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that the decreased plasma glucose curve obtained in horses with EMND during OGTTs (compared with control horses) is a result of overall enhanced glucose metabolism or abnormalities in the facilitated glucose transporters; definitive identification of the underlying mechanisms could aid in the development of appropriate treatments of EMND in horses. 相似文献
157.
Inge Bouwen A. J. Wit Jeanne Dijkstra 《European journal of plant pathology / European Foundation for Plant Pathology》1978,84(5):175-183
Cucumber mosaic virus (CMV) was isolated fromYucca flaccida. The isolate was identified as CMV by host range, ways of transmission, physical properties and serology. No symptoms appeared on healthyYucca seedlings inoculated with purified virus or virus-containing sap, neither could the virus be recovered from these plants. 相似文献
158.
George M Barrington John M Gay Inge S Eriks William C Davis James F Evermann Carlene Emerson Jennifer L O'Rourke Mary J Hamilton Daniel S Bradway 《Journal of veterinary diagnostic investigation》2003,15(2):195-200
As part of investigating diagnostic strategies for Mycobacterium avium subsp. paratuberculosis (Map), serial results from polymerase chain reaction (PCR) on extraintestinal tissues (blood, milk, and liver) were compared with those from more conventional detection methods including serum enzyme-linked immunosorbent assay (ELISA), fecal culture, and fecal PCR. Three cows previously identified as being subclinically infected with Map were selected for the study. Blood, milk, and feces were collected daily and liver biopsies were obtained weekly for a 30-day period. Unexpectedly, a substantial daily variation in serum ELISA sample to positive (S/P) ratios was observed in all 3 cows. In contrast, fecal culture results were consistently positive. However, whereas fecal culture colony counts were consistently high for 2 cows throughout the study, colony counts from the third cow varied from day to day. Diagnostic sensitivity of PCR for fecal, blood, milk, and liver samples in these advanced subclinically infected cows was 87%, 40%, 96%, and 93%, respectively. 相似文献
159.
160.
Joy E. Tomlinson Bud C. Tennant Alyssa Struzyna Dawn Mrad Nimet Browne Dorothy Whelchel Philip J. Johnson Camilla Jamieson Christiane V. Lhr Robert Bildfell Erica C. McKenzie Melissa Laverack Randall W. Renshaw Edward Dubovi Amit Kapoor Richard S. Meirs Rodney Belgrave Julie Engiles Gerlinde R. Van de Walle Thomas J. Divers 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2019,33(1):258-265