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951.
A fundamental study about the selective foam separation of protein mixture was carried out. A solution containing two proteins, ovalbumin (OA) and lysozyme (LZ), and an anionic surfactant, sodium dodecyl sulfate (SDS), was adjusted to pH 6.0, which referred to an intermediate state between the isoelectric points of the proteins. The solution was processed by continuous foam separation. The results showed that a proper addition of SDS greatly improved the selective recovery of LZ to OA. The experimental data were well explained by a simple model that most of cationic protein molecules (LZ) are associated with SDS and the adsorption of all the species including LZ-SDS complexes are subjected to Langmuir adsorption isotherm. The results also showed that one of the Langmuir parameters, which means a kind of lyophillic property of adsorbed material, of LZ-SDS complexes was extremely large as compared with that of primary protein. 相似文献
952.
Heng-Dao Quan Hui-E Yang Masanori Tamura Akira Sekiya 《Journal of fluorine chemistry》2007,128(3):190-195
In this report, a simple process for preparing HFC-245fa through the reaction of 1,1,1,3,3-pentachloropropane (PCP) and anhydrous HF via two-step vapor-phase catalytic fluorination is described. The antimony pentafluoride catalyst was supported on inert porous materials to improve the catalytic activity. The resulting process catalyst not only exhibited high catalytic activity and excellent thermo-stability, but also improved the performance of SbF5, in terms of hygroscopicity and corrosion. 相似文献
953.
Takeshi Takeda Koutaro Arai Hirohisa Shimokawa Akira Tsubouchi 《Tetrahedron letters》2005,46(5):775-778
Cyclopropanes were obtained by the titanocene(II)-promoted reaction of thioacetals with vinyl pivalate. It was also found that vinycyclopropanes were produced by a similar treatment of thioacetals with the titanocene(II) species in the presence of 1,3-dienes. 相似文献
954.
Drying dissipative structural patterns formed in the course of drying colloidal crystals of silica spheres (110 nm in diameter)
in water, methyl alcohol, ethyl alcohol, 1-propyl alcohol, diethyl ether, and in the mixtures of ethyl alcohol with the other
solvents above have been studied on a cover glass. The macroscopic broad rings were formed in the outside edges of the dried
film for all the solvents examined. Furthermore, much distinct broad rings appeared in the inner area when the solvents were
ethyl alcohol, methyl alcohol, and their mixtures. Profiles of the thickness of the dried films were sensitive to the organic
solvents and explained well with changes in the surface tensions, boiling points, and viscosities of the solvents. The macroscopic
and microscopic spoke-like crack patterns formed. The drying area (or the drying time) increased (or decreased) as the surface
tension of the solvent decreased. However, the absolute values of these drying parameters are determined also by the boiling
points of the solvents. Importance of the fundamental properties of the solvents is supported in addition to the characteristics
of colloidal particles in the drying dissipative pattern formation. 相似文献
955.
Dusanka Ž. Obadović Anikó Vajda Maya Garić A. Bubnov Vera Hamplová M. Kašpar Katalin Fodor-Csorba 《Journal of Thermal Analysis and Calorimetry》2005,80(2):519-523
Summary Thermal properties of a homologous series of ferroelectric liquid crystals S-(-)-[4-(2-n-alkoxy-propionyloxy)]biphenyl-4'-[n-alkoxy-(3,5-dimethyl)]benzoate have been investigated by polarizing optical microscopy and differential scanning calorimetry.
The mesophases were identified and confirmed by X-ray too. Three binary mixtures were prepared from the individual homologues.
In one of the mixtures (Mix1), the ferroelectric SmC* phase has broadened and became enantiotropic. This mesophase remained
monotropic in the other two mixtures (Mix2, Mix3). The chiral nematic N* phase did not appear in Mix1, but remained monotropic
for the other two mixtures. Two molecular parameters, the layer spacing and the average intermolecular distance have been
calculated from the X-ray results for the homologues and their mixtures. An intercalated tail-to-tail packing of molecules
was found both in the single compounds and their mixtures resulting in the layer spacing about half of the molecular length
of the single compounds. 相似文献
956.
Miniaturizing all dimensions of apparatus, such as electronics and computers, is the current trend followed by scientists
in various fields. The idea of Lab-on-a-Chip has significantly expanded and found its broad applications in analytical chemistry.
Microplasmas can act as a sample excitation source and are the miniaturized versions of full-sized plasmas. These can be created
in various forms, such as direct current, microwave induced, capacitively coupled and inductively coupled plasmas. Scaling
down the size would reduce the amount of gases, liquids and consumables required, as well as the sample analysis time, which
in turn would decrease the operating costs. Therefore, several research groups are involved in the development of microplasmas
for utilisation in analytical instruments. 相似文献
957.
958.
Summary The potential ranges of polarization of a pair of dropping mercury electrodes, over which the two mercury droplets coalesced, were measured as functions of ionic concentrations for various electrolytes. In the case of simple inorganic electrolytes the condition of coalescence obtained was proved to be in quantitative agreement with theVerwey-Overbeek theory of coagulation of lyophobic sols, thus indicating that the interaction between sub-microscopic particles of hydrophobic sols is essentially the same as that between macroscopic mercury droplets. While, in the case of sodium citrate solutions two kinds of marked deviations from the theory were observed, which appeared to be due to the specific adsorption of citrate ions and to the formation of protective interfacial films.
Zusammenfassung Die Potentialbereiche der Polariation eines Paares von Quecksilber-Tropfelektroden, über die die beiden Quecksilbertropfen koaleszieren, werden als Funktion der Ionenkonzentration verschiedener Elektrolyte gemessen. Im Fall einfacher anorganischer Elektrolyte wurde die erhaltene Bedingung der Koaleszenz mit der Theorie vonVerwey-Overbeek der Kaogulation lyophober Sole geprüft und in quantitativer übereinstimmung befunden. Das zeigt, da\ die Wechselwirkung zwischen submikroskopischen Partikeln hydrophober Sole im wesentlichen dieselbe ist wie zwischen den makroskopischen Quecksilbertröpfchen. Dagegen ergaben sich im Fall von Natriumzitratlösungen zwei Arten markanter Abweichungen von der Theorie. Diese scheinen spezifische Adsorption der Zitrationen und die Ausbildung von SchutzgrenzflÄchenfilmen zur Ursache zu haben.相似文献
959.
960.