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991.
Static Theory for Planar Ferromagnets and Antiferromagnets 总被引:2,自引:0,他引:2
Here we generalize the “BBH”-asymptotic analysis to a simplified mathematical model for the planar ferromagnets and antiferromagnets.
To develop such a static theory is a necessary step for a rigorous mathematical justification of dynamical laws for the magnetic
vortices formally derived in [1] and [2].
Received March 15, 2001, Accepted May 16, 2001 相似文献
992.
Yapeng Fang Saphwan Al-Assaf Glyn O. Phillips Katsuyoshi Nishinari Takahiro Funami Peter A. Williams 《Structural chemistry》2009,20(2):317-324
The physiological functions of the two ions, Ca2+ and H+, in controlling mechanical properties of plant cell wall are reviewed. The interactions of these ions with major cell wall
polysaccharides during cell growth and development are described. Experimental results for Ca2+/H+-induced molecular associations of some polysaccharides in solutions are also given. This article aims to bridge the understandings
of molecular associations in solutions (in vitro) with those occurring in cell wall matrix of high order structure (in vivo). 相似文献
993.
Ji‐Fang Fu Li‐Yi Shi Shuai Yuan Qing‐Dong Zhong Deng‐Song Zhang Yi Chen Jun Wu 《先进技术聚合物》2008,19(11):1597-1607
New hyperbranched poly(trimellitic anhydride‐triethylene glycol) ester epoxy (HTTE) is synthesized and used to toughen diglycidyl ether of bisphenol A (DGEBA) 4,4′‐diaminodiphenylmethane (DDM) resin system. The effects of content and generation number of HTTE on the performance of the cured systems are studied in detail. The impact strength is improved 2–7 times for HTTE/DGEBA blends compared with that of the unmodified system. Scanning electron microscopy (SEM) of fracture surface shows cavitations at center and fibrous yielding phenomenon at edge which indicated that the particle cavitations, shear yield deformation, and in situ toughness mechanism are the main toughening mechanisms. The dynamic mechanical thermal analyzer (DMA) analyses suggest that phase separation occurred as interpenetrating polymer networks (IPNs) for the HTTE/DGEBA amine systems. The IPN maintains transparency and shows higher modulus than the neat epoxy. The glass transition temperature (Tg) decreases to some extent compared with the neat epoxy. The Tg increases with increase in the generation number from first to third of HTTE and the concentrations of hard segment. The HTTE leads to a small decrease in thermal stability with the increasing content from TGA analysis. The thermal stability increases with increase in the generation number from first to third. Moreover, HTTE promotes char formation in the HTTE/DGEBA blends. The increase in thermal properties from first to third generation number is attributed to the increase in the molar mass and intramolecular hydrogen bridges, the increasing interaction of the HTTE/DGEBA IPNs, and the increasing crosslinking density due to the availability of a greater number of end hydroxyl and end epoxide functions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
994.
Zhang Ting Fang Daoyuan 《偏微分方程(英文版)》2008,21(4):347-376
We prove the local existence and uniqueness of the strong solution to the 3-D full Navier-Stokes equations whose the viscosity coefficients and the thermal conductivity coefficient depend on the density and the temperature. The initial density may vanish in an open set and the domain could be bounded or unbounded. Finally, we show the blow-up of the smooth solution to the compressible Navier-Stokes equations in R^n (n 〉 1) when the initial density has compactly support and the initial total momentum is nonzero. 相似文献
995.
996.
997.
电感耦合等离子体原子发射光谱法测定电解金属锰中硒、铁、硅 总被引:1,自引:0,他引:1
本文采用稀硫酸溶解试样,ICP-AES法同时测定电解金属锰中硒、铁、硅,通过对溶样酸、锰基体以及背景的研究,确定了分析条件。该方法简便具有良好的精密度和准确性,相对标准偏差不大于2.68%,回收率为98%-105%。经t检验与经典法无显著性差异。 相似文献
998.
999.
L. Xiao Y. Q. Li S. F. Wang Z. Fang G. Z. Qiu 《Journal of Thermal Analysis and Calorimetry》2009,95(2):565-569
The principle for the electro-generative simultaneous leaching (EGSL) is applied to simultaneous leaching of pyrite-MnO2 in this paper. A galvanic system for the bio-electro-generative simultaneous leaching (BEGSL) has been set up. The equation
of electric quantity vs. time is used to study the effect of produced sulfur on electro-generative efficiency and quantity. It has been shown that
the resistance decreased in the presence of Acidithiobacillus thiooxidans (A. thiooxidans) with the increase of electro-generative efficiency. The effects of temperature and grain size on rate of ferrous extraction
from pyrite under the conditions of presence and absence of A. thiooxidans were studied, respectively. The changes in the extraction rate of Fe2+ as particle size in presence of A. thiooxidans were more evident than that in the absence, which indicated that the extraction in bio-electro-generative leaching was affected
by particle size remarkably. Around the optimum culture temperature for A. thiooxidans, the bigger change in the conversion rate of Fe2+ was depending on temperature. The transferred charge in BEGSL including part of S0 to sulfate group in the presence of (A. thiooxidans) which is called as biologic electric quantity, and the ratio of biologic electric quantity reached to 58.10% in 72 h among
the all-transferred charge.
Supported by the major state basic research development program (No. 2004CB619204); the National Science Foundation of China
(No. 50374077); the Education Department Foundation of Hunan Province (No. 07D069). 相似文献
1000.
In this paper, hybrid bidirectional associative memory neural networks with discrete delays is considered. By ingeniously importing real parameters di > 0(i = 1,2,···,n) which can be adjusted, we establish some new sufficient conditions for the dynamical characteristics of hybrid bidirectional associative memory neural networks with discrete delays by the method of variation of parameters and some analysis techniques. Our results generalize and improve the related results in [10,11]. Our work is significant... 相似文献