伊兹米特地震发生的构造环境分析

土耳其地震构造具有新生性。东安纳托利亚地震带和北安纳托亚地震带的活动断裂都是晚第三纪以来开始出现、演化和发展的,而土耳其西部地震区的张性断陷盆地出现的时代更晚。土耳其活动构造类型丰富：东部发育压性或压扭性构造;北部为走滑型断裂;西部则是拉张型正断裂;中部为一个构造相对稳定的块体,即安纳托利亚块体。土耳其是研究块体与周缘断裂构造相互关系以及断裂力学相互转换的一个理想场所。北安纳托利亚断裂带是一条典型     

伊兹米特地震地表破裂带和发震构造特点

１９９９年伊慈米特７．４级地震地表破裂带表现清楚。在几何学特点上,它基本上由４个破裂段斜裂组合而成,沿破裂段可见不同的构造组相样式。在破裂段的阶区,主要发育张性构造。破裂段的最在工为５１ｍ,在运动学上,以右旋走滑运动为主,最大位错３．８ｍ‘走滑段最大垂直位错０．６ｍ。向观震中与地表最大位理合,基本上处于破裂带中间地段。地城寺表破裂带的动力学和几何学特征与震源机制解反映出来的结果相一致。     

Discovery of the Early Mesozoic granulite xenoliths in North China Craton

The discovery of the Early Mesozoic basic granulite xenoliths in the Harqin area of the Inner Mongolia Autonomous Region (for short Inner Mongolia) is reported for the first time in this paper. According to the mineral assemblage the xenoliths include two-pyroxene granulite, clinopyroxene granulite, and hypersthene granulite. Their protolytes are mainly gabbroite rocks. The zircon U?Pb age of the granulite xenoliths is 251 Ma, and K?Ar age of the hypersthene is 229 Ma. They represent the times of metamorphism and cooling of the granulite facies respectively. The host rock of the xenoliths is Early Mesozoic biotite-quartz diorites, whose whole-rock K?Ar age is 219 Ma. This discovery confirms existence of an Early Mesozoic underplating in the North China Craton, which is of much importance in research on the Early Mesozoic mantle-crust interaction in the concerned area.     

有机高分子改性土动力特性试验研究

翻浆冒泥是铁路路基主要病害之一。由于翻浆冒泥造成基床的软化和道碴板结引起道床整体弹性的降低 ,直接影响列车安全运营。实践证明用化学灌浆方法整治这种病害可取得良好效果。为评价选用的有机高分子浆液对路基基床上的改性效果 ,模拟现场土性条件、应力条件、列车循环动力条件和排水条件 ,进行了室内循环动三轴试验。试验结果表明 ,有机高分子浆液改性土动强度显著提高 ,动力特性明显改善。 改性效果在工程实践中得到验证。     

利用伴随法优化非线性潮汐模型的开边界条件：Ⅰ.伴随方程的建立及“？…

本研究采用基于最优控制理论的伴随法,把观测资料同化到陆架海域潮汐数值模型中去,优化开边界条件,提高数值预报的精度。潮汐模型的控制方程为考虑平流项、非线性底摩擦和侧向涡动性项的非线性浅不方程组;采用Ｌａｇｒａｎｇｅ乘子法建立了伴随模型。研究分两部分：第一部分即本文,建立非线性浅水方程模型的伴随方程、给出目标函数的梯度,并实现“孪生”数值试验;第二部分另文给出。     

利用伴随法优化非线性潮汐模型的开边界条件Ⅰ．伴随方程的建立及“孪生"数值试验

本研究采用基于最优控制理论的伴随法,把观测资料同化到陆架海域潮汐数值模型中去,优化开边界条件,提高数值预报的精度．潮汐模型的控制方程为考虑平流项、非线性底摩擦和侧向涡动粘性项的非线性浅水方程组;采用Lagrange乘子法建立了伴随模型．研究分两部分：第一部分即本文,建立非线性浅水方程模型的伴随方程、给出目标函数的梯度,并实现“孪生”数值试验;第二部分另文给出．     

Low- and intermediate-mass close binary evolution and the initial–final mass relation

Using Eggleton's stellar evolution code, we carry out 150 runs of Population I binary evolution calculations with the initial primary mass between 1 and 8 M_⊙, the initial mass ratio     between 1.1 and 4, and the onset of Roche lobe overflow (RLOF) at an early, middle or late Hertzsprung-gap stage. We assume that RLOF is conservative in the calculations, and find that the remnant mass of the primary may change by more than 40 per cent over the range of initial mass ratio or orbital period, for a given primary mass. This is contrary to the often-held belief that the remnant mass depends only on the progenitor mass if mass transfer begins in the Hertzsprung gap. We fit a formula, with an error less than 3.6 per cent, for the remnant (white dwarf) mass as a function of the initial mass M _1i of the primary, the initial mass ratio q _i and the radius of the primary at the onset of RLOF. We also find that a carbon–oxygen white dwarf with mass as low as 0.33 M_⊙ may be formed if the initial mass of the primary is around 2.5 M_⊙.     

The Photospheric Convection Spectrum

Spectra of the cellular photospheric flows are determined from observations acquired by the MDI instrument on the SOHO spacecraft. Spherical harmonic spectra are obtained from the full-disk observations. Fourier spectra are obtained from the high-resolution observations. The p-mode oscillation signal and instrumental artifacts are reduced by temporal filtering of the Doppler data. The resulting spectra give power (kinetic energy) per wave number for effective spherical harmonic degrees from 1 to over 3000. Significant power is found at all wavenumbers, including the small wavenumbers representative of giant cells. The time evolution of the spectral coefficients indicates that these small wavenumber components rotate at the solar rotation rate and thus represent a component of the photospheric cellular flows. The spectra show distinct peaks representing granules and supergranules but no distinct features at wavenumbers representative of mesogranules or giant cells. The observed cellular patterns and spectra are well represented by a model that includes two distinct modes – granules and supergranules.     

关于二阶伴随模型的理论研究

Hesse矩阵-目标函数关于控制变量的二阶偏导数形成的矩阵,在变分数据同化过程中以及敏感性分析等方面起着重要的作用;它可以通过建立数学模型的一阶和二阶伴随模型求得.以浅水方程模型为例,利用泛函的Gâteaux微分和Hilbert空间上伴随算子的概念,导出了一阶和二阶伴随模型并由此得到Hesse矩阵.改进了Zhi Wang等(1992)建立的二阶伴随模型理论.     

藻类中植物生长素的研究

植物生长素(auxins)是指能引起与(吲哚乙酸IAA)有同样作用的物质的总称(山田长雄等,1997),作为植物激素(phytohormones)的一种,它广泛存在于水生、陆生植物中,对其生产发育起着至关重要的生物活性作用。相对于高等植物,藻类植物生长素的研究起步较晚。本文综合了国内、外相关文献,对藻类中的植物生长素的研究作了较为全面系统的综述。