Phase equilibria in the water-dodecane-pentaoxyethylene dodecylether system

Summary Phase diagrams have been determined as a function of temperature for the following binary and ternary systems; water-pentaoxyethylene dodecylether system and water-dodecane systems containing 10, 20, 30, and 40 wt.-% of pentaoxyethylene dodecylether.X-ray diffraction examinations have revealed that the two lyotropic mesophases (neat phase and middle phase) are formed in the binary system. In the ternary systems, the mutual solubility of water and oil increases remarkably at a medium temperature near the phase inversion temperature in emulsion. The marked increase in mutual solubility is illustrated in the phase diagram as a narrow transparent region which has been regarded as a microemulsion. The electrical conductance, viscosity and type of flow behavior of the ternary system vary with temperature, corresponding to the structural changes of the system. The rheograms of the ternary systems have exhibited various types of flow behavior such asNewtonian flow, pseudoplastic flow, thixotropic hysteresis and dilatant hysteresis. Besides, differential scanning analysis has revealed endothermic peaks corresponding to phase transitions.

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Zusammenfassung Zustandsdiagramme wurden als Funktion der Temperatur für folgende binäre und ternäre Systeme bestimmt: Wasser-Pentaoxydthylen-Dodecyläther und Wasser-Dodecan mit 10, 20, 30 und 40 Gew.-% von Pentaoxyäthylen-Dodecyläther.Die Röntgen-Diffraktion-Untersuchung ergab, daß zwei lyotropische mesomorphe Phasen (neat"-Phase und middle"-Phase) in dem binären System gebildet werden. In dem ternären System nimmt die gegenseitige Löslichkeit von Wasser und Öl bei einer mittleren Temperatur in der Nähe der Temperatur der Phasenumkehrung erheblich zu. Dieser Bereich erscheint im Zustandsdiagramm als ein schmales und transparentes Gebiet, welches als eine Mikroemulsion angesehen wird. Die elektrische Leitfähigkeit, die Viskosität und der Typ des Fließverhaltens des ternären Systems verändern sich je nach der Temperatur entsprechend einer Veränderung der Struktur des Systems. Rheogramme der ternären Systeme zeigen verschiedene Typen des Fließverhaltens, wie Newtonscher Fluß, pseudoplastischer Fluß, thixotropische Hysterese, dilatantische Hysterese. Die differentialkalorimetrische Analyse zeigte endotherme Effekte bei den entsprechenden Phasenumwandlungen.

     

Syntheses and electrochemical behaviour of novel dmit or dmio (dithiolato) cobalt(iii) complexes with a η5-cyclopentadienyl or η5-pentamethylcyclopentadienyl ring

Four novel cobalt(III) complexes with a cyclopentadienyl or pentamethylcyclopentadienyl ring and dmit or dmio ligands were synthesized, and their electrochemical behaviour was investigated. All these complexes exhibited three one-electron transfer steps: one reduction and two oxidation steps. In addition, a novel organosulphur compound was afforded by electrochemical oxidation of dmit cobalt complex. Thus, these complexes may have considerable synthetic potential as precursors for electron reservoirs and organosulphur compounds.     

Note on Hadamard tournaments of Szekeres type

An Hadamard 3-design involving an Hadamard tournament of Szekeres type involves and Hadamard tournament which is not equivalent with an Hadamard tournament of Szekeres type.     

Synthesis of the bicyclo[7.3.0]dodecatrienediyne core of the C-1027 chromophore

[reaction: see text] C-1027, an extremely potent antitumor agent, is composed of chromophore 1 and an apoprotein. Here we report a general and efficient route to the exceedingly reactive bicyclo[7.3.0]dodecatrienediyne core of 1, utilizing selenoxide elimination and epoxide deoxygenation to build the cyclopentadiene and enediyne structures, respectively.     

Magnetic order in lightly doped La2-xSrxCuO4

We study long wavelength magnetic excitations in lightly doped La2-xSrxCuO4 (x相似文献   

Magic doping fractions for high-temperature superconductors

We report hole-doping dependence of the in-plane resistivity rho(ab) in a cuprate superconductor La(2-x)Sr(x)CuO4, carefully examined using a series of high-quality single crystals. Our detailed measurements find a tendency towards charge ordering at particular rational hole-doping fractions of 1/16, 3/32, 1/8, and 3/16. This observation appears to suggest a specific form of charge order and is most consistent with the recent theoretical prediction of the checkerboard-type ordering of the Cooper pairs at rational doping fractions x = (2m+1)/2n, with integers m and n.