CUBIC LIPID-WATER PHASES - STRUCTURES AND BIOMEMBRANE ASPECTS
CUBIC LIPID-WATER PHASES - STRUCTURES AND BIOMEMBRANE ASPECTS
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DOI：
10.1021/j100358a010
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发表时间：
1989-10-19
影响因子：
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通讯作者：
LARSSON, K
中科院分区：
文献类型：
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作者：
LARSSON, K
结论加权调和平均法可作为理解和开发高7”c超导体的一个简单的指导原则。每个原子都有其独特的净能力（方程式1）与周围其他不同的原子交换电子。因此，高-7-，氧化物的复杂结构必须是由于原子电负性（方程式2）的必要微妙平衡，以创造一个最佳的位场超导发生。电负性平衡概念下的化学键的研究意味着通过静电力的相互作用的重要性，一个观点被证明是有效的情况下，YBa 2Cu 307。[19]然而，应当注意的是，这种论点有其局限性。因此，有序或无序结构（例如，SnTa 3）和正常或奇数化学计量（例如，Nb-Sn和Ge-Nb系统的情况）的氧化物特性的细微差异没有反映在xwh-a的值中。此外，至少在PbSb的一种情况下，xwh-a的值落入高π ^氧化物的临界范围内。因此，该方法不是一个笼统的概括。然而，它似乎有资格作为一种方便但有效的方法来排除或预测可能的新超导体。
ConclusionsThe weighted harmonic mean approach may be useful as a simple guideline in understanding and developing high-7" c su-perconductors. Each atomhas its unique net ability (eq 1) to exchange electrons with other different atoms surrounding it. Thus, the complex structure for a high-7-,, oxide must be due to the necessarily delicate balance of the atomic electronegativities (eq 2) in order to create a potential field that is optimum for the superconduction to occur. Studies of chemical bonds following the concept of electronegativity equilibration implies the impor-tance of interactions through electrostatic force, a viewpoint shown to be valid for the case of YBa2Cu307. 19 It should be cautioned however that this type of argument has its limitations. Thus, the subtle difference in superconductive properties of ordered or disordered structure (eg, SnTa3) and normal or odd stoichiometry (eg, the cases of Nb-Sn and Ge-Nb systems) are not reflected in the values of xwh-Also, at least in one case for PbSb, the value of xwhfalls into the critical range for high-7^ oxides. Therefore, the method is not a sweeping generality. However, it seems to qualify as a convenient but effective way to eliminate or predict possible new superconductors.