磁性石榴石薄膜的磁力显微镜研究

本文采用磁力显微镜（ＭＦＭ）对磁性石榴石（ＹＧｄＢｉ）３（ＧａＦｅ）５Ｏ１２薄膜的磁畴结构进行了观察研究。实验结果表明，磁性针尖的磁特性进行对石榴石ＭＦＭ图像的影响较大，而且随着针尖与样品间距的增大，磁针尖对石榴石畴结构的影响有所降低。另外，改变针尖的磁化方向，得到的石榴石磁畴结构也有所不同。     

频域分波法研究涂覆于金属表面的手征介质层的电磁反射特性

本文利用频域分波法研究了平面电磁波入射的涂覆于金属表面的无限大层状手征介质了反射特性。频域分波法是电磁场领域新近发展起来的一种计算方法，其特点是在频域内通过数学物理变换把平面电磁波分为前行波和后行波，从而清晰地了解介质中电磁波的传输特性。本文通过理论推导和数值计算，得出了一些有用的结论，为设计防电磁反射涂层提供了理论指导。     

直立摇板简谐摇荡造二维波时所受水动力矩的频域二阶解和时域线性解

本文给出直立摇板简谐摇荡造二维波时所受水动力矩的频域二阶解和时域线性解的解析表达式,可供估算摇板式造波机设计功率时使用,也可为摇板所受水动力矩时域非线性数值计算提供比较的依据。     

F-X域等道距道内插

SimonSpitz（1989）提出的用F－X域预测技术实现道内插的方法，尽管有许多优点，但还是存在计算量大、精度低等一些问题。本文给出了一种新的F－X域实现道内插的方法，该方法是利用F－X域预测算子包含了所有反射波同相轴的倾角信息这一特性来实现道内插。它不必像常规方法那样扫描反射波同相轴的倾角，而且即使存在严重的空间仅频时，也可得到较好的内插效果。理论与实际资料试验的结果表明，该方法具有速度快、精度高、内插出的地震道波形自然、不受空间仅频影响等优点，但前提是要求在作道内播之前道距必须相等。     

Walls in liquid crystalline polymers: an electron microscopy study

Walls between domains in an annealed liquid crystal polymer are examined in the transmission electron microscope. The associated contrast in bright field and for various positions of aperture in dark field has been interpreted in terms of the chain reorientation routes across the walls. In addition, the possible wall orientations for a given pair of adjacent domains have been analysed in the light of the necessity of constant chain flux normal to the wall. This condition is also shown to limit the available reorientation routes and simplify the experimental determination of wall structure. Specimens of a thermotropic copolyester annealed for 5 s at 300°C show walls which tend to lie parallel to the original shear direction. The chain orientation in the wall is locally more closely confined to the specimen plane than in the domains, and the distortion type is twist. After longer anneals the walls change contrast in bright field and appear as dark veins. Detailed analysis of micrographs obtained under different imaging conditions shows that the change in character of the walls is associated with a change in reorientation route. The chain axes within the walls that appear as dark veins rotate through the orientation where they are nearly perpendicular to the specimen plane. The stereographic projection is used throughout to illustrate the orientation relationships between the adjacent domains, the chain axes within the wall and the orientation of the wall itself.     

标准粘性边界法应用的限制

本文证明标准粘性边界法只有在平面波且波前方向垂直于边界时才是正确的,其它如球面波等情况均不成立。     

应用小波尺度域地震波衰减属性检测气层

本文从小波域瞬时参数和尺度能量方程出发,提出小波尺度域的能量属性和瞬时属性在一定的尺度范围内可以表征地震信号的衰减特征,并把它们定义为小波尺度域地震波衰减属性。其含义为：①实际地震信号的尺度能量在极值点尺度达到最大,从该尺度起的“带通”范围内,随尺度的减小,反射信号的尺度能量呈指数降低;②由极值点尺度起向小尺度方向的“带通”区域内所计算的尺度能量称为地震波尺度能量衰减属性,相应尺度的瞬时参数剖面也归结为地震波小渡尺度域衰减属性范畴。理论模型研究和实例分析表明,小波衰减属性较常规的瞬时振幅属性对气层的敏感性强。当检测薄的含气地层或地震记录中含噪声时。小波衰减属性的检测效果明显好于常规的瞬时振幅属性。     

Engineering allosteric protein switches by domain insertion

Domain insertion is proving to be an effective way to construct hybrid proteins exhibiting switch-like behavior. In this strategy, two existing domains, the first exhibiting a signal recognition function and the second containing the function to be modulated, are fused such that the recognition of the signal by the first domain is transmitted to the second domain, thereby modulating its activity. Recent directed evolution experiments indicate that the structural space comprised of the recombination of unrelated protein domains may be rich in switching behavior, particularly when the circular permutation of domains is also employed. This bodes well for potential basic science, sensing and therapeutic applications of molecular switches.     

A new mutation in the yeast aspartate kinase induces threonine accumulation in a temperature-regulated way

In Saccharomyces cerevisiae, aspartate kinase (the HOM3 product) regulates the metabolic flux through the threonine biosynthetic pathway through feedback inhibition by the end product. In order to obtain a strain able to produce threonine in a controlled way, we have isolated a mutant allele (HOM3-ts31d) that gives rise to a deregulated aspartate kinase. This allele has been isolated as an extragenic suppressor of ilv1, which confers an Ilv+ phenotype at 37 degrees C but not at 22 degrees C. We have stated that at high temperature the mutant aspartate kinase is slightly more deregulated and shows a higher specific activity, inducing threonine accumulation. The HOM3-ts31d allele carries a mutation that leads to a Ser399 --> Phe substitution in the postulated regulatory region of the enzyme. We have detected other changes in the nucleotide sequence but they are also present in the parental strain, reflecting the genetic differences between different wild-type strains. A sequence comparison among all the reported mutant aspartate kinases suggests that not all residues involved in regulation of the activity are clustered in the so-called regulatory domain, as is the case of that mutated in AK-R7, another deregulated aspartate kinase obtained with the same strategy of ilv1 suppression.     

Reliability and behavior domain validity: Reformulation and historical critique.

Determination of the reliability of psychological scales has remained a problem over the last 50 years because of a rigid adherence to unobjective and unrealistic postulates about the nature of measurement. From the general form of the reliability of an unstratified composite several computational formulae are derived. These derivations make no assumptions about underlying factors or of statistically equivalent test-samples but rather are derived on the basis of the objective principles of domain sampling. 27 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)