Cavitation and the interaction between macroscopic hydrophobic surfaces     

Christenson HK  Claesson PM 《Science (New York, N.Y.)》1988,239(4838):390-392

The interaction in water of neutral hydrocarbon and fluorocarbon surfaces, prepared by Langmuir-Blodgett deposition of surfactant monolayers, has been investigated. The attraction between these hydrophobic surfaces can be measured at separations of 70 to 90 nanometers and thus is of considerably greater range than previously found. Spontaneous cavitation occurred as soon as the fluorocarbon surfaces were brought into contact but occurred between the hydrocarbon surfaces only after separation from contact. The very long range forces measured are a consequence of the metastability of water films between macroscopic hydrophobic surfaces. Thus the hydrophobic interaction between macroscopic surfaces may not be related to water structure in the same way that the hydrophobic effect between nonpolar molecules is related to water structure.  相似文献   

Heterogeneous and epitaxial nucleation of protein crystals on mineral surfaces     

McPherson A  Shlichta P 《Science (New York, N.Y.)》1988,239(4838):385-387

Fifty different mineral samples were tested as potential heterogeneous or epitaxial nucleants for four commonly crystallized proteins. It was found, by conventional protein crystallization techniques, that for each protein there was a set of mineral substrates that promoted nucleation of crystals at lower critical levels of supersaturation than required for spontaneous growth. Numerous examples, involving all four proteins, were observed of modification of crystal habit and, in some cases, unit cell properties promoted by the presence of the mineral nucleants. In at least one case, the growth of lysozyme on the mineral apophyllite, it was shown by lattice analysis and x-ray diffraction that the nucleation and growth of the protein crystal on the mineral was likely to involve a direct lattice match.  相似文献   

Shattered stars: supernova remnants and the interstellar medium     

Murdin P 《Science (New York, N.Y.)》1988,241(4861):105-106

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Soviet science     

Abelson PH 《Science (New York, N.Y.)》1988,239(4843):961

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Response: icosahedral symmetry     

Steinhardt PJ 《Science (New York, N.Y.)》1988,239(4843):963-964

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Einstein in his youth: the collected papers of albert einstein     

Loewenberg P 《Science (New York, N.Y.)》1988,239(4839):510-512

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Improving u.s. Capabilities in technology     

Abelson PH 《Science (New York, N.Y.)》1988,242(4878):493

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Dynamic properties of molecularly thin liquid films     

Israelachvili JN  McGuiggan PM  Homola AM 《Science (New York, N.Y.)》1988,240(4849):189-191

An experimental technique is described for simultaneously measuring the static and dynamic interactions of very thin liquid films between two surfaces as they are moved normally or laterally relative to each other. Film thickness can be measured and controlled to 1 angstrom. Initial results are presented of the transition in the physical properties of liquid films only one molecular layer thick to thicker films whose properties are practically indistinguishable from the bulk. In particular, the results show that two molecularly smooth surfaces, when close together in simple liquids, slide (shear) past each other while separated by a discrete number of molecular layers, and that the frictional force is "quantized" with the number of layers.  相似文献   

Outside Views of Science: Science under Scrutiny     

Durbin PT 《Science (New York, N.Y.)》1984,224(4652):984

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Book reviews     

C. Fisher  A. B. Gilbert 《British poultry science》1984,25(2):294-295

The T.M.E. System of Feed Evaluation. I.R. Sibbald, Animal Research Centre Contribution 83‐1, Animal Research Centre, Ottawa, Ontario, Canada.

Physiology and Behaviour of the Pigeon, edited by M. Abs. 1983. 360 pages, illustrated. London, Academic Press Ltd. Price £34.00. ISBN 0 12 042950 0.  相似文献