用多极理论分析圆桩对称微波谐振腔

用多极理论计算具有复杂几何形状、圆柱对称微波腔的谐振频率,推导出用多极理论计算圆柱对称微波腔谐振频率的本征值方程。三个工程实例的计算结果表明,用多极理论计算圆柱对称微波腔谐振频率,不仅具有较高的计算精度,而且可以很方便地应用于复杂几何形状圆柱对称微波腔工程问题的设计与计算,多极理论是计算圆柱对称微波腔谐振频率的一种有效方法。     

同位旋激发能研究

在扩展的Skyrme有效相互作用下,利用Hartree-Fock理论研究了同位旋激发能与温度、密度的关系.结果表明同位旋激发能随密度的降低以及温度的增加而降低.同时研究了对称能与同位旋激发能的关系,指出对称能是同位旋激发能的一部分,且占相当大的比重.最后研究了不同的势参数下,同位旋激发能随相对中子过剩的变化关系,发现同位旋激发能较强地依赖于对称能强度系数,而对不可压缩系数以及有效质量不太敏感.从而为实验上通过研究同位旋激发能来提取核物质状态方程中的对称能部分指出了一条途径.     

High—Dimensional Integrable Models with Infinitely Dimensional Virasoro—Type Symmetry Algebra

Using every realization of the Virasoro-type symmetry algebra[σ(f1),σ(f2)]=σ(f1f2-f2f1),we can obtain various high-dimensional integrable models under the meaning that they possess infinitely many symmetries,By means of a concrete realization ,many(3 1)-dimensional equations which possess Kac-Moody-Virasoro-type infinite dimensional symmetry algebras are obtained.     

光学双焦非球面圆柱面塑料集光透镜模芯制造技术

介绍一种由一面为圆柱面 ,另一面为非球面圆柱面构成的尺寸较小的光学塑料集光镜模芯制造技术。产品技术要求 F1=∞ ,F2 =4 5 ± 0 1mm ,集光效率 >85 %。内容包括CAM软件开发、线切割加工工艺、研磨抛光技术。采用该工艺制造的模芯经检测 ,表面粗糙度Ra=0 0 35 μm ,面形误差为 0 63μm。用该模芯加工的塑料产品经美国有关公司检测 ,F1=∞ ,F2 =4 5± 0 1mm ,集光效率≥ 90 %,质量达到了设计和使用要求 ,目前已批量生产。     

自旋涨落与非常规超导配对

铜氧化物高温超导、铁基高温超导、重费米子超导和κ-型层状有机超导等超导体的超导态都与磁性有序态相邻,且超导能隙在动量空间一般存在变号.因此,这些超导体的超导机理被认为有别于常规BCS超导中的电子交换声子导致的各向同性s-波配对.在这些非常规超导中,自旋涨落被认为是导致电子形成库珀对的主要起源之一.本文主要以铜基和铁基高...     

单面柱局域共振声子晶体低频带隙特性分析及结构改进研究

基于有限元法对单面柱局域共振声子晶体进行带隙特性分析,研究了结构参数对该类型声子晶体的影响。结果表明:随着散射体高度的增加,单面柱声子晶体的第一完全带隙的起始频率逐渐降低,带宽逐渐增大;随着基板厚度的增大,单面柱声子晶体的起始频率逐渐升高,截止频率先增大后减小。并且在经典单面柱声子晶体的基础上,组合了两种新型的三组元单面柱声子晶体结构:嵌入式单面柱声子晶体(以下简称结构Ⅰ)和粘接式单面柱声子晶体(以下简称结构Ⅱ)。通过对其带隙特性的分析得出:这两种新结构与经典的单面柱声子晶体相比,都具有更低频的带隙,这对于低频减振降噪是非常有利的。本文的结果将对实际的工程应用提供一定的理论指导。     

动态柱形空穴膨胀模型及其在侵彻问题中的应用

 在侵彻问题中的应用进行了研究。通过采用相似变换求解塑性区控制方程,获得了动态柱形空穴膨胀中的弹塑性界面速度、径向应力分布、空穴表面应力的解。基于柱形空穴模型,推导了侵彻方程,并将其得到的预测结果与侵彻实验数据进行了比较。结果表明,模型的理论解与现有数据吻合得很好。 结果还显示了材料的可压缩性和塑性强化模量对柱形空穴膨胀以及侵彻阻力的影响。     

Palindromic Vectors,Symmetropy and Symmentropy as Symmetry Descriptors of Binary Data

Today, the palindromic analysis of biological sequences, based exclusively on the study of “mirror” symmetry properties, is almost unavoidable. However, other types of symmetry, such as those present in friezes, could allow us to analyze binary sequences from another point of view. New tools, such as symmetropy and symmentropy, based on new types of palindromes allow us to discriminate binarized 1/f noise sequences better than Lempel–Ziv complexity. These new palindromes with new types of symmetry also allow for better discrimination of binarized DNA sequences. A relative error of 6% of symmetropy is obtained from the HUMHBB and YEAST1 DNA sequences. A factor of 4 between the slopes obtained from the linear fits of the local symmentropies for the two DNA sequences shows the discriminative capacity of the local symmentropy. Moreover, it is highlighted that a certain number of these new palindromes of sizes greater than 30 bits are more discriminating than those of smaller sizes assimilated to those from an independent and identically distributed random variable.     

Molecular Chirality in Classical Spacetime: Solving the Controversy about the Spinning Cone Model of Rotating Molecules

The spinning cone is a model of rotating molecules used by Barron in 1986 in relation to asymmetric synthesis and to parity violation. He considered that the non-translating cone spinning about its symmetry axis has false chirality (i.e., it is not chiral), whereas Mislow concluded in 1999 that it is indeed chiral and severely criticized the true versus false chirality nomenclature introduced by Barron, who still disagreed in 2013 with the conclusion of Mislow. Here, it is shown that this controversy comes from an ambiguity in the spinning cone model and that in fact both authors were right. Light is thrown on the true chirality versus false chirality controversy with a very recently published result, which was thus unavailable to both authors: this is a new definition of chirality that encompasses the one introduced by Lord Kelvin at the end of the 19th century.