全文获取类型
收费全文 | 195篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
199篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 7篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 7篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有199条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
T. Jermy 《Entomologia Experimentalis et Applicata》1958,1(3):197-208
Zusammenfassung Zwecks Ausarbeitung biozönoseschonender, selektiver Bekämpfungsmethoden wurden die reflektorischen Bedingungen der Nahrungswahl des Kartoffelkäfers untersucht. Die überwinterten Käfer können im Freiland die Anwesenheit der Wirtspflanze höchstens aus einer Entfernung von einigen Dezimetern wahrnehmen. Jungkäfer sprechen nur nach erfolgter Dressur (= Nahrungsaufnahme) auf die von der Wirtspflanze stammenden olfaktorischen Reize an. Beim Auffinden der Pflanzen spielen die visuellen Reize bei den Alt- und Jungkäfern, allerdings nur aus kleinen Entfernungen, eine wichtige Rolle. Die Jungkäfer halten bei der Nahrungssuche eine konstante Laufrichtung ein. Die Frass-Stoffe sind nur begrenzt spezifisch, die Oligophagie des Kartoffelkäfers ist demnach auf eine negative Anpassung an vergällend wirkender Stimuli zurückzuführen. Die vergällende Wirkung der Stoffe ist von der chemischen Struktur weitgehend unabhängig. Eine Reduktion der Vermehrungsrate des Schädlings kann durch Veränderung des Reizstoffgehaltes der Wirtspflanze bzw. durch Anwendung von Vergällungsstoffen erreicht werden.
Summary In order to find selective control methods, which would not disturb the biocoenoses, the reflex mechanism of food finding and host selection by the Colorado potato beetle was investigated. The greater part of the overwintered beetles do not begin to feed just after emergence, but first migrate. Seeking the food they perceive the host plant in the field by olfaction from a distance of not more than a few decimetres. The newly hatched young beetles react upon the olfactostimuli coming from the host plant only after some training (= feeding). During the food-seeking of old and young beetles sight only plays an important role, however, within a very limited distance. If searching for food, young beetles keep a constant direction in creeping. In the Colorado beetle host selection depends mainly on taste. Feeding stimuli are not markedly specific; the oligophagy of the beetles is based largely upon the negative reactions to repellent stimuli. Repellency is to a great extent independent of chemical structure and is therefore to be found in the many different groups of compounds. For example the repellency of the Bordeaux mixture is very high and is thereupon able to reduce the rate of reproduction very considerably. The selective reduction of the biotic potential of the pest could be achieved (1) by changing the quantity of acceptants and rejectants in the host plant (by selection or by cultural methods) or (2) by applying repellents.相似文献
6.
7.
M Imboden A Nieters AJ Bircher M Brutsche N Becker M Wjst U Ackermann-Liebrich W Berger NM Probst-Hensch 《Clinical and molecular allergy : CMA》2006,4(1):1-9
Background
Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens.Methods
Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study.Results
Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated.Conclusion
Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen. 相似文献8.
10.