全文获取类型
收费全文 | 231篇 |
免费 | 14篇 |
专业分类
林业 | 4篇 |
农学 | 4篇 |
基础科学 | 1篇 |
48篇 | |
综合类 | 26篇 |
农作物 | 11篇 |
水产渔业 | 12篇 |
畜牧兽医 | 109篇 |
园艺 | 6篇 |
植物保护 | 24篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 1篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 1篇 |
2013年 | 11篇 |
2012年 | 12篇 |
2011年 | 17篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 17篇 |
2007年 | 20篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1965年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 31 毫秒
51.
Atkins SD Hidalgo-Diaz L Kalisz H Mauchline TH Hirsch PR Kerry BR 《Pest management science》2003,59(2):183-189
The nematophagous fungus, Pochonia chlamydosporia (Goddard) Zare & Gams, has been investigated as a potential biological control agent for use in integrated pest management strategies for Meloidogyne incognita (Kof & White) Chitwood in vegetable crops. The release of the fungus as a biological control agent requires a diagnostic method to monitor its spread in the environment and to gain knowledge of its ecology. Only molecular methods are sufficiently discriminating to enable the detection of specific isolates of fungi in soil. A method to extract DNA from soil was developed to increase the efficacy of PCR-based diagnostic tests that use specific primers. A selected isolate of P chlamydosporia var catenulata was applied at densities similar to those that occur naturally in nematode-suppressive soils. The fungus significantly reduced nematode infestations in soil following a tomato crop, in a strategy that combined the use of the fungus with crop rotation. The survival of the fungus in soil was also examined in controlled conditions in which it remained in soil in densities significantly greater than its original application rate for at least 5 months. Hence, it seems that populations of this fungus may be built up in soil and have significant effects on the regulation of root-knot nematode populations. 相似文献
52.
53.
54.
P J Kerry 《Research in veterinary science》1976,21(3):356-357
Sheep erythrocytes do not aggregate spontaneously but will sediment when mixed with a solution of hydroxyethylcellulose. The resulting leucocyte-rich supernatant can be used in the preparation of purified lymphocyte and granulocyte suspensions. 相似文献
55.
Sandra B. Visnovsky Preeti Panda Kerry R. Everett Ashley Lu Ruth C. Butler Robert K. Taylor Andrew R. Pitman 《Plant pathology》2020,69(7):1311-1330
Molecular detection of phytopathogens is increasingly being applied to identify regulated organisms at the border in many parts of the world. However, even with molecular tests, complete phenotyping and identification of a strain is often time consuming and sometimes inconclusive. In this study, a leaf-based pathogenicity test was used to separate pseudomonads into two groups, Group A containing pathogens, and Group B containing saprotrophs. Comparative genomics of 56 pseudomonad genomes from different plant hosts (including 29 strains from kiwifruit) agreed with kiwifruit pathogenicity test results, placing pathogens into Group A and saprotrophs into Group B. Sixteen loci were found unique to Group A. A PCR assay was developed for amplification of one of these loci, the trehalose phosphatase gene. The generation of this 655 bp amplicon was associated with production of water-soaked lesions on inoculated kiwifruit leaves by pseudomonads in Group A. This test was validated for further strains from all seven pathogenic Pseudomonas phylogroups, non-pathogenic pseudomonads, and other bacterial genera. The sensitivity of the PCR was comparable to the limit of recovery of pseudomonads by culturing. This simple PCR assay could be used as part of a testing pipeline at the border and for general surveillance for screening plants with and without symptoms, offering the potential to detect uncharacterized pseudomonads that may pose a biosecurity risk. The method was shown to be able to rapidly identify pathogens cultured from plant material with symptoms, or, more importantly, to detect pathogens directly from plant tissue. 相似文献
56.
Gunaranjan Paturi Christine A. Butts Kerry L. Bentley-Hewitt 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(3):321-323
This study investigated the impact of diets containing various levels of avocado (5, 10 and 15%) on gut health in rats fed for six weeks. Avocado-fed rats had significantly higher food intakes while their body weights remained similar to the control diet-fed rats. No significant changes in intestinal bacterial populations (ileum, cecum and colon) were found in rats fed avocado diets compared to the control diet. Ileum and colon tissues of rats fed avocado diets showed significantly higher expression of genes (β-defensin 1, mucin 3 or mucin 4) and a greater number of mucin-producing goblet cells in the colon. The percentage of avocado in the diet had varying effects in altering the biomarkers, whereby diet containing 15% avocado was the more effective diet. This study delivers new knowledge on the role of avocado on gut health in rats. 相似文献
57.
Sprague AL Boynton WV Kerry KE Janes DM Hunten DM Kim KJ Reedy RC Metzger AE 《Science (New York, N.Y.)》2004,306(5700):1364-1367
The gamma ray spectrometer on the Mars Odyssey spacecraft measured an enhancement of atmospheric argon over southern high latitudes during autumn followed by dissipation during winter and spring. Argon does not freeze at temperatures normal for southern winter (approximately 145 kelvin) and is left in the atmosphere, enriched relative to carbon dioxide (CO2), as the southern seasonal cap of CO2 frost accumulates. Calculations of seasonal transport of argon into and out of southern high latitudes point to meridional (north-south) mixing throughout southern winter and spring. 相似文献
58.
59.
Genetic studies have elucidated mechanisms that regulate aging, but there has been little progress in identifying drugs that delay aging. Here, we report that ethosuximide, trimethadione, and 3,3-diethyl-2-pyrrolidinone increase mean and maximum life-span of Caenorhabditis elegans and delay age-related declines of physiological processes, indicating that these compounds retard the aging process. These compounds, two of which are approved for human use, are anticonvulsants that modulate neural activity. These compounds also regulated neuromuscular activity in nematodes. These findings suggest that the life-span-extending activity of these compounds is related to the anticonvulsant activity and implicate neural activity in the regulation of aging. 相似文献
60.
Nitrogen dioxide gas was rapidly absorbed by soil. After a 15 min incubation at 25°C, soil at a moisture content of 16% absorbed 99% of the NO2 introduced into the gas-phase volume of a closed system. The presence of microorganisms hatl no influence on the rate of absorption of the gas by soil. The absorption of NO2 by sandy clay loam soil was not an oxygen- or temperature-dependent process nor did it depend upon the moisture content of the soil. These physical factors acquired significance only in determining the initial rate of absorption of the gas and the rate at which NO2 diffused through the soil. Exposure of soil to NO2 resulted in substantial increases in the levels of NO inf2 sup? N in the soil. Chemical oxidation of the NO inf2 sup? N resulted in an increase in NO inf3 sup? N levels. During a 14-day incubation, NO inf2 sup? N concentrations in sterile soil exposed to an atmosphere containing 100 μg ml?1 of NO2 decreased from 190 μg g?1 of soil to 105 μg g?1 with an accompanying increase in NO inf3 sup? N from 2 μg g? 1 to 63 μg g?1 of soil. Nitrogen dioxide severely inhibited the growth of both aerobic and anaerobic asymbiotic N2-fixing bacteria in soil. After a 48 h incubation at 25°C, soil aggregates exposed to an atmosphere containing 100 μg ml?1 of NO2 contained 88% and 98% fewer aerobic and anaerobic N2-fixing bacteria, respectively. C2H2-reduction measurements showed that nitrogenase synthesis and activity in artificial soil aggregates amended with 2% glucose were inhibited by 20% and 48%, respectively, when exposed to atmospheric concentrations of 35 and 3.5 μg ml?1 of NO2, respectively. 相似文献