全文获取类型
收费全文 | 179篇 |
免费 | 14篇 |
专业分类
林业 | 3篇 |
农学 | 2篇 |
48篇 | |
综合类 | 53篇 |
农作物 | 7篇 |
畜牧兽医 | 73篇 |
园艺 | 3篇 |
植物保护 | 4篇 |
出版年
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1998年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1966年 | 2篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1945年 | 3篇 |
1944年 | 1篇 |
1941年 | 2篇 |
1939年 | 1篇 |
1938年 | 1篇 |
1935年 | 1篇 |
1933年 | 1篇 |
1929年 | 2篇 |
1927年 | 1篇 |
1923年 | 1篇 |
1920年 | 1篇 |
1917年 | 2篇 |
1915年 | 1篇 |
1913年 | 1篇 |
1912年 | 2篇 |
1911年 | 3篇 |
1906年 | 1篇 |
排序方式: 共有193条查询结果,搜索用时 15 毫秒
1.
2.
Antoine LF Gady Freddy WK Hermans Marion HBJ Van de Wal Eibertus N van Loo Richard GF Visser Christian WB Bachem 《Plant methods》2009,5(1):13-14
Background
The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal. 相似文献3.
Raymond J. C. Cannon 《Pest management science》1993,37(4):331-335
Bacillus thuringiensis (Bt)-based insecticide products constitute the overwhelming majority of biopesticides but, despite having been commercially available for over 30 years, they have made little impact (<1%) on the crop-protection market as a whole. This has been largely due to poor cost-performance factors relative to synthetic organic pesticides. However, recent biotechnological advances—including genetic modification—combined with a variety of emerging opportunities, have created the prospect of the commercialisation of a new range of highly effective Bt-based biopesticides. Bioencapsulation of single-gene products—delta-endotoxins from selected Bt isolates—in killed Pseudomonad cells (Mycogen Corporation's ‘CellCap’ technology), offers a flexible delivery system with enhanced persistence. This versatile approach selects only the most appropriate biotoxins, which can be used to target a number of pest species. It is anticipated that Bt-based pesticides will continue to fill an increasing number of gaps in the panoply of synthetic crop-protection chemicals. Genetically modified products offer advantages in terms of efficacy, flexibility and safety but public concerns regarding perceived risks need to be addressed. 相似文献
4.
This case report documents an unusual tracheal foreign body (a moth) in Congo African grey parrot (Psittacus erithacus erithacus). Gross postmortem signs and histopathology results are presented. A discussion of the peculiar avian anatomy that may have contributed to the aspiration of the moth is provided. 相似文献
5.
6.
7.
An electroimmobilisation device has been developed to facilitate the automated shearing of sheep, but there is little information on its effects on the body. We have studied its effects on the cardiovascular system and on intermediary metabolism in sheep. Electroimmobilisation caused statistically significant increases in mean arterial pressure, heart rate, cardiac output, renal and hepatic and hindquarter glucose and lactate flux, organ and whole body oxygen flux, hindquarter blood flow and core temperature and decreases in arterial and posterior vena cava blood pH, renal and hepatic blood flow and PaCO2. Notably, no change occurred in PaO2. The metabolic changes demonstrated the capacity of sheep to respond to the increased muscular and cardiovascular work induced by electroimmobilisation. Pulmonary function was not compromised during electroimmobilisation as judged from blood gas changes, and the acid/base changes were rapidly reversed after electroimmobilisation. The recovery to control conditions for all perturbations generally took no longer than 30 min, consistent with a rapid and physiologically adequate reversal by the animal's homeostatic mechanisms. 相似文献
8.
9.
10.
Leinekugel X Khazipov R Cannon R Hirase H Ben-Ari Y Buzsáki G 《Science (New York, N.Y.)》2002,296(5575):2049-2052
The behavior of immature cortical networks in vivo remains largely unknown. Using multisite extracellular and patch-clamp recordings, we observed recurrent bursts of synchronized neuronal activity lasting 0.5 to 3 seconds that occurred spontaneously in the hippocampus of freely moving and anesthetized rat pups. The influence of slow rhythms (0.33 and 0.1 hertz) and the contribution of both gamma-aminobutyric acid A-mediated and glutamate receptor-mediated synaptic signals in the generation of hippocampal bursts was reminiscent of giant depolarizing potentials observed in vitro. This earliest pattern, which diversifies during the second postnatal week, could provide correlated activity for immature neurons and may underlie activity-dependent maturation of the hippocampal network. 相似文献