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41.
Alexandr Jegorov Zdenk Hork Jan ejka Bohumil Kratochvíl Ivana Císaov 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o575-o576
A new polymorph of pergolide mesylate or 8β‐[(methylsulfanyl)methyl]‐6‐propylergoline methanesulfonate, C19H27N2S+·CH3SO3−, is reported. Pergolide mesylate form II crystallizes in the trigonal system, which is unique for ergot derivatives. Although the hydrogen‐bond system in form II differs completely from that in form I, the conformation of the pergolide moiety in various related structures is very similar. 相似文献
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Ramn Macías Simon A. Barrett Jonathan Bould Udo Drfler Josef Holub John D. Kennedy Mark Thornton‐Pett Bohumil tíbr 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):520-522
Neutral 8‐(5‐iodo‐n‐pentyl)‐3‐(η5‐pentamethylcyclopentadienyl)‐arachno‐3‐rhoda‐7,8‐dithiaundecaborane, [Rh(C5H19B8IS2)(C10H15)], obtained from the [arachno‐7,8‐S2B9H10]? anion by treatment with I(CH2)5I followed by [Rh(C5Me5)Cl2]2 and N,N,N′,N′‐tetramethyl‐1,8‐diaminonaphthalene, has the 11‐vertex cluster geometry of [arachno‐7,8‐S2B9H10]?, but with an {Rh(C5Me5)} unit in the 3‐position instead of a {BH} unit, and with a –(CH2)5I chain attached exo to an S atom. 相似文献
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Jii Kvapil Z. Vitamvs B. Perner Jos. Kvapil B. Mnek O. Adametz J. Kubelka 《Crystal Research and Technology》1980,15(7):859-864
Thermoluminescence (TL) of several types of corundum crystals is described. Undoped crystals showed a weak TL at 15 and 110°C with emission at 330 and 495 nm. Good TL response at 275°C is shown by Cr doped (0.03 wt%) crystals grown by Verneuil method in the oxygen cone of the flame annealed in hydrogen at 1500–1800°C. The most intensive TL response is shown by crystals doped with Ti and Mo (∼ 10−3wt.%) grown by Czochralski method in reducing conditions. The former may be used to the detection of γ-rays dose ≥ 10−3 − 10−2 Gy, the latter ≥ 10−7 − 10−6 Gy. 相似文献
46.
Doping possibility of long ruby crystals grown by Czochralski method under reducing protective atmosphere by iron ions in described. Using the admixture of hydrocarbons to the protective atmosphere this dopage may be realized. Iron ions increases damage threshold of the Q-switched laser ruby rods. 相似文献
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Jiří Kvapil Bohumil Perner Michal Košelja Josef Kvapil 《Czechoslovak Journal of Physics》1990,40(1):99-108
YAP:Nd laser crystals suffer to a greater extent than YAG:Nd from colour centres formation. Stable brownish-yellow or green colourations are evoked by non-oxidizing treatment at high (>1500 °C) temperature. The former colouration may be attributed to holes in the oxygen neighbourhood of Y3+ at Al sites, the latter to the F+ centres. Brownish-red colouration of less stability is induced by optical pumping of Nd3+ containing crystals. It may be attributed to holes in oxygen neighbourhood of Nd3+.Dependences of the colourations on the preparation methods are described. YAP:Nd,Zr laser rods, oxygen annealing of which was followed by medium (1100–1400 °C) temperature treatment in vacuum or hydrogen showed no anomalous colouration and extremely low losses at Nd3+ emission wavelength independent of pumping power. Using such rods, an overall efficiency of 2·5% and a slope efficiency of 3·0% in CW lasers were reached. 相似文献