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991.
Man Jae Han Jong Hyuk Park Jang Yeol Lee Jae Young Jho 《Macromolecular rapid communications》2006,27(3):219-222
Summary: To develop ionic polymer‐metal composites (IPMC) with improved performance, three new ion‐exchange membranes were prepared and employed in IPMC construction. The membranes were prepared by radiation‐grafting of polystyrene sulfonic acid onto three fluoropolymers; poly(vinylidenefluoride‐co‐hexafluoropropylene), poly(ethylene‐co‐tetrafluoroethylene), and poly(tetrafluoroethylene‐co‐hexafluoropropylene). The bending displacements of the IPMCs constructed with these membranes were at least several times larger than that of Nafion IPMC of similar thickness without straightening‐back. The larger displacement was considered to be due to the higher concentration of ionic groups and consequent larger ion‐exchange capacity.
992.
Masakazu Yoshikawa Koji Nakai Hidetoshi Matsumoto Akihiko Tanioka Michael D. Guiver Gilles P. Robertson 《Macromolecular rapid communications》2007,28(21):2100-2105
It is demonstrated that polymeric materials can be directly converted into molecular (chiral) recognition nanofiber membranes by simultaneously applying an electrospray deposition and an alternative molecular imprinting during the membrane preparation process. Polysulfone with a degree of substitution of 0.88 was adopted as the candidate polymeric material for molecularly imprinted nanofiber membranes. Molecularly imprinted nanofiber membranes imprinted by Z‐D ‐Glu recognize the D ‐isomer in preference to the corresponding L ‐isomer and vice versa. The amino acid preferentially incorporated into the membrane is selectively permeated through the membrane by using a concentration gradient as a driving force for membrane transport.
993.
本文介绍了用于直接甲醇燃料电池(DMFCs)的质子交换膜(PEMs)的工作原理与性能要求。讨论了影响DMFCs国PEMs的甲醇渗透性能的因素。综述了Nation、改性Nafion膜以及其它新品种膜的研究进展。 相似文献
994.
Controlling dipole squeezing of two atoms inside a cavity via manipulating an atom outside the cavity 总被引:3,自引:0,他引:3 下载免费PDF全文
Considering that three two-level atoms are initially in the GHZ single state and two of the atoms are simultaneously put into a cavity initially in the coherent state, we investigate the dipole squeezing properties of the two atoms inside the cavity under the condition of resonant interaction. It is shown that dipole squeezing properties of the two atoms inside the cavity are strongly affected by rotation manipulating of the atom outside the cavity. 相似文献
995.
General contact conditions are developed for lipid membranes interacting with curved substrates along their edges. These include
the anchoring conditions familiar from liquid-crystal theory and accommodate non-uniform membranes and non-uniform adhesion
between a bulk fluid or membrane and a rigid substrate. The theory is illustrated through explicit solutions and numerical
simulations.
相似文献
996.
A linear perturbation analysis is performed for a class of rate-dependent materials, such as the Johnson-Cook model, in which the rate contribution to the stress can be separated from that of the plastic strain and temperature and in which the temperature rises adiabatically. The analysis is facilitated by perturbing both the rate of momentum equation and the momentum equation. An identical material stability/instability criterion is deduced from the characteristic spectral equations for one-dimensional deformation, one-dimensional shearing, and general three-dimensional field equations, and thus shows that the instability derived here is a material constitutive instability.The criteria indicate that the materials become unstable once the thermal softening overcomes the strain hardening, regardless of the strain rate. The strain rate enters the criteria through its effects on the accumulated temperature and the current stress. Based on the criterion, the three-dimensional instability surface is established in the space of plastic strain, plastic strain rate, and temperature. Instability surface is shown as a material property and independent of deformation histories or modes. Both necking and shear banding are simulated to validate the excellent predictive capability of the criterion. 相似文献
997.
998.
本文介绍了高温云纹实验的背景,详细叙述了高温实验专用炉设计原理和控温系统,解决了紊流的影响,在高温下可获得清晰稳定的图像。控温系统以8031单片机为基础,采用了三次回归方程计算测量温度,运用PID调节控制,提高了高温实验炉的可靠性。 相似文献
999.
Y.?MurakamiEmail author Y.?Murakami K.?Naito T.?Itoh T.?Kobayashim N.?Fujii 《Shock Waves》2003,13(2):149-154
Oxidation of cyclo-C5H5 was investigated by monitoring O atoms and also CO molecules behind the reflected shock of cyclo-C5H6 / O2 /Ar and C6H5OCH3 /O2 /Ar mixtures. In both mixtures we could observe the formation of O atoms produced by the reaction of cyclo-C5H5 + O
cyclo-C5H5O + O and from the kinetic analysis of these time profiles the rate constant for this reaction was determined to be
kJ/RT) cm3 mol-1 s-1. The possibility of CO formation by the reaction of cyclo-C5H5O
C4H5 + CO was also investigated but because of the subsequent reactions forming CO molecules no direct information for the reaction of cyclo-C5H5O
C4H5 + CO was derived.Received: 3 February 2003, Accepted: 17 June 2003, Published online: 5 August 2003 相似文献
1000.