共查询到20条相似文献,搜索用时 15 毫秒
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Theophil Schläpfer 《Development genes and evolution》1963,154(4):378-404
Ohne ZusammenfassungMeinem verehrten Lehrer, Herrn Prof. Dr. E.Hadorn, bin ich für die Anregung und Leitung der Arbeit sowie für die Mithilfe bei den Transplantationen sehr zu Dank verpflichtet. 相似文献
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Der Einfluss des Menschen auf die Vegetation 总被引:4,自引:0,他引:4
Herbert Sukopp 《Plant Ecology》1969,17(1):360-371
Summary Comparing different directions of human influence on the plant world in various regions one can propose to consider the following three dimensions: intensity, extent and duration of influence. The effect of man can be graded upon hemerobic (Jalas) degrees; see fig. 2. An example for mapping vegetation in such grades is given in fig. 3. Criteria for demarcating the degrees of human influence are mentioned on p. 369. 相似文献
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Dozent Dr. Wilhelm Nultsch 《Planta》1962,57(6):613-623
Summary A method for quantitative evaluation of the photokinetic action in Cyanophyceae is described. The value of the photokinetic action, i.e. the quotient of distances covered in light and dark, was determined forPhormidium autumnale in white and monochromatic light. From 0.02 to 30000 lux the photokinetic reaction ofPh. autumnale is positive, above 30000 lux negative. The zero threshold of photokinesis is at 0.01–0.02 lux, the optimum at 2000 lux.By means of an interference filter monochromator system the action spectrum of photokinesis was determined for the range between 317 and 800 m under conditions of equal quantum flux related to an energy of 1000 erg/cm2·sec at 670 m. These results were compared with the pigment absorptionin vitro andin vivo.The main maximum at 680 m and the smaller peak at 620 m coincide with the absorption maxima of chlorophyll a in the living cell. The region 430–440 m was also active without a distinct maximum. Irradiation of the principal absorption region of the carotenoids and phycobilins is only slightly effective for the latter. The distinct maximum at 390 m and the strong action of UV and blueviolet light must be due to an unknown pigment.Thus visible irradiation is photokinetically effective according to its absorption by chlorophyll a, whereas no or little relation exists to carotenoids and phycobilins.
Mit 6 Textabbildungen.
Herrn Prof. Dr. Dr. h.c.E. G. Pringsheim zum 80. Geburtstag gewidmet. 相似文献
Mit 6 Textabbildungen.
Herrn Prof. Dr. Dr. h.c.E. G. Pringsheim zum 80. Geburtstag gewidmet. 相似文献
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Ohne ZusammenfassungMit 5 Textabbildungen 相似文献
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Zusammenfassung Bei 11 Studenten aus Mainz wurde im September 1964 in Oberstdorf/Allgäu (843 m) und im September 1965 auf der Nordseeinsel Norderney täglich die Ausscheidung der 17-Ketosteroide untersucht, um den Adaptationsverlauf zu prüfen. Alle Versuchspersonen hatten eine erhöhte 17-KS-Ausscheidung,die an der Nordsee höher war als im Gebirge. Der Höhepunkt der Ausscheidung lag um den 10. Tag. Es bestanden individuelle Unterschiede in der 17-KS-Ausscheidung. Je niedriger diese vorher war, desto höher war die relative Steigerung im Gebirge und an der See.Während der Beobachtungsperiode waren wetterbedingte Abweichungen von den periodischen Schwankungen nachweisbar.
The 17-ketosteroid excretion of 11 students from the University of Mainz was investigated during September 1964 in Oberstdorf (843 m) and in September 1965 on the North Sea island Norderney. All subjects had an increased 17-ketosteroid excretion which was higher at the sea than in the mountains.The maximum of the values was around the 10th day. There were individual differences; the lower the excretion at Mainz the higher was the relative increase at both locations. During the observation period deviations from the periodic changes were observed which were due to the effect of weather.
Resume Afin d'examiner l'adaptation de 11 étudiants au milieu,on a analysé chaque jour leur excrétion de 17-kétostéroïde. Ces essais ont eu lieu en septembre 1964 à Oberstdorf/Allgäu (843 m d'altitude) et en septembre 1965 sur lïle de Norderney dans la Mer du Nord. On a pu déceler une augmentation de 17-kétostéroïde chez toutes les personnes examinées. Cette augmentation fut toutefois plus marquée au bord de la mer qu'en montagne. L'excrétion en fut maximum le 10ème jour.On a remarqué en outre des différences individuelle. Plus l'excrétion était faible au départ et plus l'augmentation relative était marquée ausi bien au bord de la mer qu'en montagne.Pendant la période des examens, on a pu prouver des divergences météorotropiques par rapport aux fluctuations périodiques.相似文献
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Ohne Zusammenfassung 相似文献
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Summary Seedlings of white seeded mustard (Sinapis alba L.) have been investigated with respect to the influence of light (red, far-red, white) on the rate of formation of primordia at the apex. The results show that the formation of primordia is strongly increased by light and that this control is exerted mainlyvia the phytochrome system and the high energy reaction )=blue, far-red reaction) of photomorphogenesis (cf.Mohr 1962). Apparently photosynthesis can also be important in the case that the supply of organic material limits the rate of those growth processes which have been induced by the photomorphogenetically effective radiation.The morphological appearance of the stem apex and of the youngest primordia is the same in light and dark. It is concluded that light increases the rate of primordia formation by promoting the mitotic activity in the apical meristem. Growth of the primary leaves of the mustard seedling is also greatly promoted by light. Both the phytochrome system and the high energy reaction system are involved. Experiments indicate that this control by light is exerted in a way similar to the light control of the growth of the cotyledons (Mohr 1959b).
Mit 7 Textabbildungen 相似文献
Mit 7 Textabbildungen 相似文献
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