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Carolyn E. M. Morris A. E. Alexander A. G. Parts 《Journal of polymer science. Part A, Polymer chemistry》1966,4(5):985-995
The polymerization of methyl acrylate in water and in dilute, aqueous, soap solutions, initiated by potassium peroxydisulfate, has been investigated, a dilatometric method being used to follow the conversion. It has been shown that small amounts of an anionic soap increase the rate of reaction while a cationic soap has the reverse effect. The change of molecular weight with conversion has also been examined as well as the effect of the exclusion of oxygen from the system. 相似文献
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Ü . Parts V. M. H. Ruutu J. H. Koivuniemi M. Krusius E. V. Thuneberg G. E. Volovik 《Physica B: Condensed Matter》1995,210(3-4):311-333
When a cylindrical container filled with superfluid 3He---A is rotated around its symmetry axis, several different configurations of quantized vorticity are possible: which of them will be preferred depends on the specifics how the rotating state is formed. The most unusual is the vortex sheet, a domain wall in the order parameter texture into which vortex lines are confined. This metastable structure has the lowest critical velocity of formation if a domain wall with the appropriate orientation is already present in the container. In this case the vortex sheet becomes the preferred rotating state which provides the solid-body rotation of the superfluid component on an averaged scale. Its presence can be identified from the cw NMR spectrum which samples the order parameter texture. Here the experimental properties of the vortex sheet are reviewed, as deduced from NMR measurements. 相似文献
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提出了一种测量有机材料的磁化率各向异性的方法。原理是利用掺杂对丝状液晶磁场扭曲费雷德里克兹转变影响的现象,将待测有机材料作为掺杂物,采用光学相位延迟法测量掺杂丝状液晶磁场扭曲费雷德里克兹转变阈值和过程,从而获得待测有机材料的磁化率各向异性。通过实验测量,从原理和方法上验证了测量方法的可行性。测得有机材料磁化率各向异性的同时也为有机材料的表征提供了一种方法。测量方法适用于无固有磁矩的有机材料。 相似文献
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Ü. Parts V. V. Avilov J. H. Koivuniemi M. Krusius J. J. Ruohio V. M. H. Ruutu 《Czechoslovak Journal of Physics》1996,46(1):13-14
In superfluid3He-A singly and doubly quantized vortex lines can coexist in a rotating container. We measure with NMR techniques the radial distribution of the two vortex types in an array of vortex lines. The radial composition is found to depend on the procedure by which the array has been formed. The result shows that in superfluid3He the energy barriers separating different configurations of the vortex array are inpenetrably high for a metastable state to relax. 相似文献
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V. M. Ruutu J. Kopu M. Krusius Ü. Parts B. Plaçais E. V. Thuneberg Wen Xu 《Czechoslovak Journal of Physics》1996,46(1):7-8
Vortex lines with continuous (singularity-free) core structure are usually formed when superfluid3He-A is accelerated to rotation. The critical counterflow velocityv c (T), at which vortex formation starts, has been measured with cw NMR. The onset of vortex formation is found to depend on the order parameter texture and differs from that of singular core vortices in4He-II or3He-B due to much larger length scale. 相似文献