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'High pressure' in keywords Facet   section ZfN Section B  [X]
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1Author    Heinz-Jörg Kurth, Dieter Bieniek, Friedhelm KörteRequires cookie*
 Title    Hochdruckreaktionen, XIII [1] Synthese von(—)Cannabidiol unter hohen Drucken High Pressure Reactions, XIII [1] Synthesis of (—) Cannabidiol at High Pressure  
 Abstract    Cannabidiol 3 has been synthesized under high pressure conditions (7-8 kbar, 150 °C) from Olivetol 1 and trans-p-Menthadien-(2,8) -ol -(1) 2 with 41% yield. The influence of different solvents on the yield has been studied. 
  Reference    Z. Naturforsch. 36b, 275—276 (1981); eingegangen am 17. November 1980 
  Published    1981 
  Keywords    High Pressure, Cannabidiol, Stereospecific Synthesis 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0275_n.pdf 
 Identifier    ZNB-1981-36b-0275_n 
 Volume    36 
2Author    J. R., D. B., F. K.Requires cookie*
 Title    High Pressure Reactions, IX 1 Isomerizations at High Pressures  
 Abstract    Cyclooctatetraene dimerises at high pres­ sure (12 Kbar, 20 °C) to the isomers 2 and 3. At 120 °C compound 2 isomerises quanti­ tatively to compound 3. The conversion rate of Hexamethyldewarbenzene to Hexamethyl-benzene at high pressures depends on kind of solvent, whereas the influence of tempera­ ture is small in the range between 2 0 ° and ' 80 °C. 
  Reference    (Z. Naturforsch. 30b, 290 [1975]; eingegangen am 17. Oktober 1974) 
  Published    1975 
  Keywords    High Pressure, Cyclooctatetraene, Dimerisation, Hexamethyldewarbenzene, Isomerization 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0290_n.pdf 
 Identifier    ZNB-1975-30b-0290_n 
 Volume    30 
3Author    Rolf-Rüdiger Krüger, W. Alter, AbrielRequires cookie*
 Title    Über das Hochdruckverhalten von Gips On the Behaviour of Gypsum under High Pressure  
 Abstract    The decom position o f gypsum (dehydration) was studied in the pressure range 7 .5 -6 0 kbar and the temperature range 7 5 -4 0 0 °C using a belt type apparatus. Surprisingly, gypsum is rather stable even at pressures greater than 20 kbar contradicting the results o f a calculation o f the space requirement o f the competing phases (A I I -C a S 0 4 + H-,0; Hemihydrate + H20). Only when rising the temperature, as the most important thermodynamic variable for this reaction, the kinetically controlled decomposition starts. N o acceleration o f the dehydration process under shear stress (simple squeezer device) could be detected due to the limited (not geological) time. 
  Reference    Z. Naturforsch. 45b, 1221—1226 (1990); eingegangen am 27. Februar 1990 
  Published    1990 
  Keywords    Gypsum, Hydrates, High-Pressure, D ecom position 
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 TEI-XML for    default:Reihe_B/45/ZNB-1990-45b-1221.pdf 
 Identifier    ZNB-1990-45b-1221 
 Volume    45 
4Author    H. Einz, Jürgen Beister, K. Arl Syassen, Jürgen KleinRequires cookie*
 Title    Phase Transition of N a3As under Pressure  
 Abstract    We have investigated the high pressure behaviour of N a3As by powder X-ray diffraction. At 3.6 G Pa the material undergoes a reversible phase transition from the N a3As structure (P 6 3/ mmc, a = 487.4(8) pm, c = 851.5(20) pm, Z = 2, at 3.6 G Pa) to the Li3Bi structure type (Fm 3m , a = 683.5(15) pm, Z = 4, at 3.6 GaP). The equation of states is given for the pressure range up to 26 GPa. Results are discussed with respect to structural properties of related A3BV-compounds. 
  Reference    Z. Naturforsch. 45b, 1388—1392 (1990); received M arch 7 1990 
  Published    1990 
  Keywords    High Pressure, Crystal Structure, Phase Transition 
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 TEI-XML for    default:Reihe_B/45/ZNB-1990-45b-1388.pdf 
 Identifier    ZNB-1990-45b-1388 
 Volume    45 
5Author    Oliver Schilke, EberhardH. Ohaus, H. Arro Lentz, JeongR. KimRequires cookie*
 Title    HPTLC-Analyse von Ginsenosiden zur Bewertung von Ginseng-Extraktionen mit Methanol-Wasser, Wasser oder Ammoniak HPTLC Analyses o f Ginsenosides for the Evaluation of Ginseng Extractions with M ethanol-W ater, W ater or Am m onia  
 Abstract    Korean Ginseng roots were extracted with m ethanol-w ater, water and liquid and supercriti­ cal ammonia. The yields of the extracts by different methods are reported. The extracts were analyzed by high-performance thin-layer chrom atography. Retention value factors of ginsen­ osides are tabellized. The absolute yields have been measured in mg ginsenoside per g ginseng root for the used standard ginsenosides. Formally the am m onia extraction at 334 K and 26 bar is found to be favourable. The supercritical condition of 418 K and 130 bar leads to a decom­ position of the ginsenosides. Possibilities of fractionation by different solvents or different temperatures are indicated, but attem pts are still required to get fractions o f several extraction agents. 
  Reference    Z. Naturforsch. 46b, 829—834 (1991); eingegangen am 17. Dezember 1990 
  Published    1991 
  Keywords    Ginsenoside, Extraction, H PTLC Analysis, High Pressure 
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 TEI-XML for    default:Reihe_B/46/ZNB-1991-46b-0829.pdf 
 Identifier    ZNB-1991-46b-0829 
 Volume    46 
6Author    Hk Müller-Buschbaum, H. PauschRequires cookie*
 Title    Über eine neue Präparationstechnik in der Feststoffchemie, II Hochdruck-Hochtemperatursynthesen mit C02 -Laser A New Preparative Technique in Solid State Chemistry, II High Pressure -High Temperature Reactions with CCVLasers  
 Abstract    A new technique to realize solid state reactions under high oxygen pressure is reported. This method is based on the use of CC>2-Laser radiation in combination with autoclave technique. The experimental set-up is described. 
  Reference    Z. Naturforsch. 34b, 375—377 (1979); eingegangen am 20. November 1978 
  Published    1979 
  Keywords    Solid State Chemistry, CC>2-Laser, High Pressure, High Temperature 
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 TEI-XML for    default:Reihe_B/34/ZNB-1979-34b-0375.pdf 
 Identifier    ZNB-1979-34b-0375 
 Volume    34