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31.
Gisèle Ruiz Goldstein 《Physica D: Nonlinear Phenomena》2011,240(8):754-766
We consider in this article a Cahn-Hilliard model in a bounded domain with non-permeable walls, characterized by dynamic-type boundary conditions. Dynamic boundary conditions for the Cahn-Hilliard system have recently been proposed by physicists in order to account for the interactions with the walls in confined systems and are obtained by writing that the total bulk mass is conserved and that there is a relaxation dynamics on the boundary. However, in the case of non-permeable walls, one should also expect some mass on the boundary. It thus seems more realistic to assume that the total mass, in the bulk and on the boundary, is conserved, which leads to boundary conditions of a different type. For the resulting mathematical model, we prove the existence and uniqueness of weak solutions and study their asymptotic behavior as time goes to infinity. 相似文献
32.
B. Hellebrand R.A. Gunasekaran P.L. Steger D. Bäuerle 《Applied Physics A: Materials Science & Processing》1997,65(3):235-240
3 Ox with both orthorhombic and tetragonal structure were synthesized using different heat treatments. From each type, a series
of oxygen-depleted samples, denoted as “O” and “T”, with oxygen contents 6.5<x<7.0 were prepared by annealing in argon at
different temperatures in the range 300–550 °C. For O- and T-samples, superconductivity vanishes below x≈6.8 and x≈6.6, respectively.
While T-samples show a continuous variation of both Tc and the unit-cell volume with x, O-samples show coinciding anomalies in these dependences. In all cases, the oxygen loss
with respect to fully oxygenated samples was determined by both weight measurements (δw) and iodometric titration (δt) With T-samples, δw and δt are in good agreement, whereas with O-samples considerable discrepancies between these values were found. These disparities
in
the properties of O- and T-samples may be related to differences in the oxygen sublattice.
Received: 25 February 1997/Accepted: 27 February 1997 相似文献
33.
1 C60 (A = Rb, Cs, K) and RbC70 have been investigated by neutron scattering. The studies include measurements in the high temperature rotator-, the polymer-,
the dimer- and the low temperature isolator-phase and include investigations of the particular phase transitions. It is found
that each of the phases can be characterized by specific features of its lattice dynamics which can be used for detailed studies
of the dynamics of the rotator-polymer and the dimer-polymer transitions. Particular insight in the lattice dynamics is obtained
from model calculations for the RbC60 polymer and dimer phase.
Received: 13 September 1996/Accepted: 11 November 1996 相似文献
34.
采用新型核素64Cu标记了含丙烯胺肟[Pn AO(3,3,9,9-Tetramethyl-4,8-diazaundecane-2,10-dione Dioxime)]结构的硝基咪唑类乏氧显像剂Pn AO-1-(2-nitroimidazole)[BMS181321],通过优化反应条件,于室温下反应10 min后即得到高放化纯度和高比活度的标记化合物64Cu-BMS181321.目标产物经放射性高效液相色谱检测验证和体外稳定性实验确认后,通过尾静脉注射到人源胰腺癌(PANC-1细胞系)裸鼠体内,分别于注射显像剂4和8 h后进行小动物正电子发射断层扫描显像(Micro-PET).结果表明,4 h左右肿瘤乏氧区域有良好的放射性浓聚.64Cu-BMS181321的合成及其分子显像研究开创了64Cu标记硝基咪唑类乏氧显像剂进行乏氧显像的先例,经进一步药物临床实验评价后,64Cu-BMS181321有望成为具有良好前景的PET乏氧显像药物. 相似文献
35.
36.
针对2起RCS-931型继电保护64K通道的典型故障现象,进行了详细的分析和研究。分析了电流差动保护装置、PCM和光端机通信设备之间的2M、64K通道配合关系,并结合纵联电流差动保护工作原理,在现场通道试验基础上,阐明了通道故障产生的原因,64K保护用通道存在的缺陷,提出了行之有效解决方案和整改措施,为使用64K通道的... 相似文献
37.
38.
39.
In this paper we study the maximal operators and the convolution operators Tδ associated with multipliers of the form
40.
We define a family of weighted geometric means {G(t;ω;A)}t∈[0,1]n where ω and A vary over all positive probability vectors in Rn and n-tuples of positive definite matrices resp. Each of these weighted geometric means interpolates between the weighted ALM (t=0n) and BMP (t=1n) geometric means (ALM and BMP geometric means have been defined by Ando-Li-Mathias and Bini-Meini-Poloni, respectively.) We show that the weighted geometric means satisfy multidimensional versions of all properties that one would expect for a two-variable weighted geometric mean. 相似文献