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441.
442.
Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate
a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions.
Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding
programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white
clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients
of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual
yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant
colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties
increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively
correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield
in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic
conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that
breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture. 相似文献
443.
Franz Conen Kristiina Karhu Jens Leifeld Barbara Seth Pekka Vanhala Jari Liski Christine Alewell 《Soil biology & biochemistry》2008,40(10):2703-2705
Predictions of future climate change critically depend on the temperature sensitivity of soil organic carbon decomposition. One question of debate is whether temperature sensitivity differs between young or labile and old or more stable carbon pools. We re-analysed soil that has previously led to the conclusion that old soil carbon is more temperature sensitive. The re-analysis gave different results compared to the earlier study, most likely due to small differences in an otherwise very similar experimental approach. This study illustrates how conclusions may depend upon details of the experimental setting. 相似文献
444.
To investigate the effect of water temperature on gamete maturation and gamete quality, European grayling (Thymalus thymallus) were held under different temperature regimes prior to spawning. Maturation of males and females and their gamete quality
depended strongly on temperature regime. The highest percentages of maturing fish and highest gamete quality were obtained
under a creek water temperature regime with natural seasonal fluctuations. In warmed creek water (3–4°C), at a constant temperature
of 8–9°C, and under an abruptly increasing temperature, regime maturation rates and gamete quality were reduced. The effect
was more pronounced in females than in males. The spawning dates of different wild Austrian grayling populations were also
correlated with water temperature data collected during the last 10–15 years. The mean spawning date expressed as the number
of days from 21 December until spawning ranged from 98 to 111 days for lower elevation populations, while it was considerably
delayed for an alpine population. All populations spawned at water temperatures of 5.5–7.2°C. Regression analysis indicated
that spawning date correlated with (1) the overall mean water temperature from 21 December until spawning, (2) the mean water
temperature during both the last 10 days and 15 days before spawning, and (3) the difference between mean January temperature
and that of the last 15 days before spawning. The regression functions indicate that an increase in water temperature from
21 December to spawning of 1°C advances spawning by 5? days, and an increase of 1°C in the last 10–15 days advances spawning
by 3? days. 相似文献
445.
J. Franz 《Journal of pest science》1956,29(3):38-41
Ohne Zusammenfassung 相似文献
446.
J. Franz 《Journal of pest science》1956,29(2):20-24
Zusammenfassung Vor drei Jahren setzten in der Bundesrepublik Deutschland amtliche Bestrebungen ein, die schwierigen Aufgaben der biologischen Schädlingsbekämpfung zu sichten und die vordringlichsten von ihnen einer Lösung zuzuführen. Die Schriftleitung erachtete es für notwendig, einen Überblick über die Aufgaben und den Stand der Arbeiten zu vermitteln, und hat daher den Verfasser um einen Bericht über die in der Bundesrepublik laufenden Untersuchungen. In seiner Eigenschaft als deutscher Fachvertreter und zugleich Vizepräsident der internationalen Kommission für biologische Bekämpfung (CILB) ist Herr Regierungsrat Dr. J. Franz unserem Wunsche nachgekommen, in kurzen Zügen auch auf die internationalen Beziehungen und Zusammenarbeit einzugehen. 相似文献
447.
Conraths FJ Werner O Methner U Geue L Schulze F Hänel I Sachse K Hotzel H Schubert E Melzer F Mettenleiter TC 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(5-6):186-204
The use of conventional battery cages for hens will be prohibited in Germany in 2007. Only few studies, however, have considered the differences between battery cages and alternative systems with regard to infectious diseases. The existing gaps in the current knowledge need to be closed by research and measures must be developed that will prevent the spread of viral, bacterial, and parasitic infections in alternative poultry housing systems.With regard to virus infections, avian influenza requires particular attention. Since wild birds, particularly anseriformes, represent a reservoir for avian influenza viruses, free-ranging poultry is much more at risk of infection than birds in closed hen-houses. Appropriate measures must prevent direct contact with wild birds and transmission via contaminated water, feed, or equipment. Several bacterial infections of poultry represent zoonoses. Salmonella and Campylobacter are considered as particularly important. To avoid a potential increase in the risk of infection for consumers due to poultry keeping systems that might favour infections with bacterial zoonotic agents, there is a special need for research in this area. With regard to parasitic infections, coccidioses may cause problems in alternative poultry housing systems, and lead to considerable economic consequences. The epidemiological situation concerning infections with Histomonas meleagridis needs to be analysed. Since all compounds that had been used for prophylactic or therapeutic purposes in the past have been banned, there is a need to develop new drugs which are safe for animals and humans. 相似文献
448.
Franz S Kahlbacher H Schuh M Schmerold I 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(3-4):153-159
The aim of this study was to investigate in 20 healthy pigs the practicability of the oesophagogastroduodenoscopic examination technique in regard to equipment, method of examination, indications and its suitability as a diagnostical tool for the assessment of the oesophagus, stomach and upper duodenum in one procedure. Preparation of the patient for endoscopy, the procedure of the endoscopic examination as well as the topographical findings of the upper intestinal tract including the duodenum until the flexura duodenojejunalis are described. Flexible oesophagogastroduodenoscopy is a suitable method for the observation and natural visualisation of mucosal surfaces and for the digital documentation of peristaltic movements. The procedure is easy to perform in anaesthetized animals, is in most cases completed within 15 min, and can be repeated in the same animal. Indications of this interesting diagnostic imaging technique are discussed. 相似文献
449.
450.