Obstbau in einer Oase     

Dr. Georg Ebert  Ibrahim Abdulhadi  Prof. Dr. Hassan Ali-Dinar 《Erwerbs-Obstbau》2005,47(2-3):61-66

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Über die Mischungsverhältnisse in Mischzellen des Statusalbomaculatus vonAntirrhinum majus L.     

Rudolf Hagemann 《Genetic Resources and Crop Evolution》1961,9(1):163-170

Summary 1. In variegated leaves of a statusalbomaculatus ofAntirrhinum majus L. mixed cells are present containing two types of plastids (green and pale). Data are given for the frequency of the different ratios of green and pale plastids (Table 1).2. In young foliage leaves (Fig. 1), bracts, and sepals (Fig. 2) the frequency distribution of the different ratios is very similar to a normal curve.3. From the mean and this frequency distribution it is concluded that in mixed cells green and pale plastids have nearly the same rate of multiplication.4. In old foliage leaves a skew distribution is found (Fig. 1). The reason for this is, that the pale plastids decay with increasing age of the leaves. Therefore in mixed cells the green plastids prevail.5. In order to demonstrate differences in the rate of multiplication between two types of plastids it is necessary to pay attention to changes of the ratios caused by aging. Secondary changes of this kind must be excluded.

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1. (status)albomaculatus yAntirrhinum majus L. (Mischzellen), , . (. 1).2. . 1), (. 2) .3. , .4. (. 1). , , .5. ( ), , , , .

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Nymphal diapause and its photoperiodic control in the tick Ixodes scapularis (Acari: Ixodidae)     

Belozerov VN  Naumov RL 《Folia parasitologica》2002,49(4):314-318

It is shown experimentally that the option between developmental diapause and non-diapause development in nymphs of Ixodes scapularis Say, 1821 (Middle Atlantic population) is determined by photoperiodic conditions according to a two-step photoperiodic reaction of short-day long-day type. Diapause arrest of development is induced by an impact of either long day upon unfed nymphs, or short day upon engorged nymphs, while non-diapause development completed in 2-2.5 months at 20 degrees C needs the change from short-day to long-day conditions. Some ecophysiological aspects of mechanisms controlling seasonal development of ticks belonging to Ixodes ricinus complex are discussed.  相似文献   

Nochmals zum Artikel: der Rath’sche Verschulrahmen     

Rudolf Hacker 《European Journal of Forest Research》1907,29(12):683-684

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Georg Lang 《Forstwissenschaftliches Centralblatt》1898,20(7):344-365

Ohne Zusammenfassung  相似文献   

Bücheranzeigen     

Dr. Georg Henner  M.  Rubner 《European Journal of Forest Research》1926,48(9):642-644

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Beiträge zur Bekämpfung und Begutachtung der Dörrobstmotte (Plodia interpunctella) und der Kakaomotte (Ephestia elutella)     

Rudolf Lehmensick 《Journal of pest science》1935,11(12):137-139

Ohne Zusammenfassung  相似文献   

    

Rudolf Geiger 《Forstwissenschaftliches Centralblatt》1926,48(5):337-360

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Meffung des Expofitionsklimas II     

Rudolf Geiger 《Forstwissenschaftliches Centralblatt》1927,49(23):853-859

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Alkaline sulfite–anthraquinone (AS/AQ) pulping of wheat straw and totally chlorine free (TCF) bleaching of pulps     

Sahab Hedjazi  Othar Kordsachia  Rudolf Patt  Ahmad Jahan Latibari  Ulrike Tschirner 《Industrial Crops and Products》2009,29(1):27-36

Alkaline sulfite–anthraquinone (AS/AQ) pulping of wheat straw and totally chlorine free (TCF) bleaching of resulting pulps was investigated. Wheat straw was supplied by the Ferdosii University Experimental Station in Northeastern Iran, cleaned and chopped into about 3–5 cm long pieces. In the AS/AQ pulping experiments, the active alkali charge on oven dry wheat straw, heating time to maximum cooking temperature, AQ dose and liquor to straw ratio were kept constant at 16%, 60 min, 0.1% and 4/1, respectively. The alkali ratio, Na₂SO₃/NaOH, calculated as NaOH, was varied from 20/80 to 80/20. Cooking time at maximum temperature was varied from 30 to 90 min and maximum cooking temperature was adjusted between 152 and 160 °C. Reference soda and soda/AQ pulps were produced.AS/AQ and soda/AQ pulps with kappa numbers below 15 were produced easily. Cooking of corresponding soda pulps under comparable conditions stopped at a kappa number of 25. The characteristics of unbleached AS/AQ, soda/AQ and soda pulps were compared. AS/AQ and soda/AQ pulps had similar tensile strength but tear was in favor to AS/AQ. The latter had much higher yield and brightness.TCF bleaching of AS/AQ pulp was performed in O Q (OP) or O Q (OP) P sequences. Oxygen delignification (O) resulted in a delignification degree of approximately one third. Followed by a chelating treatment (Q) and a subsequent (OP) stage under drastic conditions a brightness of 82.7% ISO was achieved in an O Q (OP) sequence. The sequence O Q (OP) P, with 2% H₂O₂ in the final P stage, improved brightness from 77.2% ISO after the OP stage to 83.6% ISO. Bleaching led to only small losses in tensile and burst strength but enhanced tear strength. Short beating in a Jokro mill was sufficient to attain good pulp strength. The results of this study indicate that AS/AQ pulping and TCF bleaching is a convincing alternative to produce high-quality pulp from wheat straw for writing and printing paper.  相似文献