加速广义Laguerre多项式级数的Laplace变换的数值反演方法

本文利用Levin t-变换迭代法，对加速广义Laguerre多项式级数，提出了一种新的Laplace变换的数值反演方法，这种方法在精度上和数值稳定性上的效果都较好。     

柯特斯系数和显式阿达姆斯格式系数的程序设计

本文提出了利用牛顿－－柯特斯公式进行数值积分计算时，柯特斯系数的程序设计方法和利用阿达姆斯方法解微分方程时显示阿达姆斯格式系数的程序设计方法。     

Phase transition of FeO and stratification in Earth's outer core

Light elements such as oxygen in Earth's core influence the physical properties of the iron alloys that exist in this region. Describing the high-pressure behavior of these materials at core conditions constrains models of core structure and dynamics. From x-ray diffraction measurements of iron monoxide (FeO) at high pressure and temperature, we show that sodium chloride (NaCl)-type (B1) FeO transforms to a cesium chloride (CsCl)-type (B2) phase above 240 gigapascals at 4000 kelvin with 2% density increase. The oxygen-bearing liquid in the middle of the outer core therefore has a modified Fe-O bonding environment that, according to our numerical simulations, suppresses convection. The phase-induced stratification is seismologically invisible but strongly affects the geodynamo.     

Antarctic ice sheet: preliminary results of first core hole to bedrock

The Antarctic ice sheet at Byrd Station has been core-drilled to bedrock; the vertical thickness of the ice is 2164 meters. Liquid water-indicative of pressure melting-was encountered at the bed. Heat flow through the base of the ice sheet is estimated at 1.8 microcalories per square centimeter per second. The minimum temperature was -28.8 degrees C at 800 meters; maximum ice density, 0.9206 at 1000 meters. Core studies reveal the existence of a chemically pure, structurally stratified sheet comprising bubbly ice to 900 meters that transforms to bubble-free deformed ice, with substantially vertically orientated c-axis structure, below 1200 meters. Below 1800 meters the deformed ice structure gives way to large annealed crystals. Several thin layers of dirt between 1300 and 1700 meters are tentatively identified as volcanic ash, and horizontally banded debris, including fragments of granite, is present in the basal ice.     

Stress and fold localization in thin elastic membranes

Thin elastic membranes supported on a much softer elastic solid or a fluid deviate from their flat geometries upon compression. We demonstrate that periodic wrinkling is only one possible solution for such strained membranes. Folds, which involve highly localized curvature, appear whenever the membrane is compressed beyond a third of its initial wrinkle wavelength. Eventually the surface transforms into a symmetry-broken state with flat regions of membrane coexisting with locally folded points, reminiscent of a crumpled, unsupported membrane. We provide general scaling laws for the wrinkled and folded states and proved the transition with numerical and experimental supported membranes. Our work provides insight into the interfacial stability of such diverse systems as biological membranes such as lung surfactant and nanoparticle thin films.     

一种新的对流（扩散）方程式的差分格式

本文通过分析研究，提出了一种新的差分格式。结果表明该方法有较高精度和稳定性，且可以防止因差分格式而产生的振动解和负浓度等问题。     

Transformation in Garnet from Orthorhombic Perovskite to LiNbO3 Phase on Release of Pressure

High-pressure in situ x-ray diffraction and transmission electron microscopy on quenched samples show that natural garnet transforms to orthorhombic perovskite (and minor coexisting phases) containing increasing amounts of aluminum with increasing pressure. This suggests that the perovskite is the dominant host mineral for aluminum in Earth's lower mantle. Orthorhombic perovskite is quenched from approximately 35 gigapascals but, because of the increased aluminum content, transforms to the LiNbO3 structure upon quenching from approximately 60 gigapascals.     

一种设计空间机构的代数方法

本文介绍了对儡数和四元数代数,并指出它在空间机构和机器人设计中的重要意义。 文中以空间RCPRC五杆机构的位形计算为实例,推导出计算公式并算出了相应结果。     

薄板弯曲问题差分计算的图式

在薄板小挠度弯曲问题计算中,有限差分法是一种有效的数值解法,文献[1]给出了求解薄板小挠度弯曲问题的基本差分方程,文章[2]在文献[1]的基础上推算了具有自由边界的薄板弯曲问题等间距差分网格的具体差分计算图式。本文在文献[1]和文章[2]的基础上,推求了具有自由边界薄板弯曲问题不等间距网格的差分计算图式,以便在工程实际中直接利用上述图式列出差分方程,不必再利用边界条件来消除虚结点的挠度而得差分方程,简便实用。     

求解大规模非光滑优化问题的一种修正Hestenes-Stiefel共轭梯度算法

利用Moreau-Yosida正则化技术和非单调线搜索技术,设计了一种针对大规模非光滑优化问题的修正Hestenes-Stiefel共轭梯度算法.该算法的搜索方向不仅自动满足充分下降条件,而且属于信赖域.在适当条件下,新算法全局收敛.初步的数值实验也表明新算法对于求解大规模非光滑无约束凸优化问题是有效的.     

保单持有人退保行为对变额年金利益保证风险对冲的影响研究

盛传数百年的王阳明于正德二年“寓居”岳麓书院“斤斤讲良知之学”的旧说，当正之为正德三年阳明先生病中游览岳麓书院。虽然阳明此行并未讲学，但有讲学之意，它实际开启了明代书院与学术再度一体辉煌的大门，预示着书院的王学时代即将来临。此后近百年，王门后学徐爱、季本、邹守益、罗洪先、王乔龄、罗汝芳、张元忭、邹元标等接连讲学岳麓，使其成为王学的重要讲坛。但宋元以来形成的朱张之学根深蒂固，影响深远，始终居于正统地位，王阳明及其后学皆表现出应有的尊重，故而岳麓在明代始终没有那种浮诞不逞、空谈良知之习，保留了重践履、务实学的传统。     

Polymorphs of Alumina Predicted by First Principles: Putting Pressure on the Ruby Pressure Scale

Fully optimized quantum mechanical calculations indicate that Al2O3 transforms from the corundum structure to the as yet unobserved Rh2O3 (II) structure at about 78 gigapascals, and it further transforms to Pbnm-perovskite structure at 223 gigapascals. The predicted x-ray spectrum of the Rh2O3 (II) structure is similar to that of the corundum structure, suggesting that the Rh2O3 (II) structure could go undetected in high-pressure x-ray measurements. It is therefore possible that the ruby (Cr3+-doped corundum) fluorescence pressure scale is sensitive to the thermal history of the ruby chips in a given experiment.     

Three-dimensional instabilities of mantle convection with multiple phase transitions

The effects of multiple phase transitions on mantle convection are investigated by numerical simulations that are based on three-dimensional models. These simulations show that cold sheets of mantle material collide at junctions, merge, and form a strong downflow that is stopped temporarily by the transition zone. The accumulated cold material gives rise to a strong gravitational instability that causes the cold mass to sink rapidly into the lower mantle. This process promotes a massive exchange between the lower and upper mantles and triggers a global instability in the adjacent plume system. This mechanism may be cyclic in nature and may be linked to the generation of superplumes.     

拖拉机悬挂喷雾机作业性能控制的原理和方法

本文在阐明悬挂喷雾机组性能控制原理的基础上,给出了影响喷施质量的可控参数集合及最佳数值范围、调节元件的不失效条件和工作规范选择及实施的一般步骤。     

一种简便的含裂纹梁的有限元模型

研究了含裂纹梁的弯曲变形问题。建立了一种简便的含裂纹梁的有限元模型,基于断裂力学理论和力的平衡方程,利用柔度矩阵和刚度矩阵的物理含义,导出了含裂纹梁单元的刚度矩阵。基于Matlab软件进行了数值模拟运算,给出了裂纹对梁挠度的影响。     

微型往复式电动锯锯切机构的计算机辅助动力学分析

以微型往复式电动锯锯切机构为研究对象，对立了运动学和动力学荒废主了运动副摩擦、各种的实际质量及滑块的具体结构，利用数值计算方法进行了计算机模拟，计算结果表明，附加平衡块可以减小机构的冲击和振动。同时求得了使机械的冲击振动最小的平衡块质量与质心位置，并给出了反映冲击振动大小与平衡块质量和质心位置关系的立体图。     

基于有限元的内腐蚀管道极限压力计算

利用有限元软件,采用幂硬化随动强化材料模型、缺陷正交面切割法和模型完全六面体单元网格化方法,建立了数值分析模型,在规范B31G的基础上求得准确度更高的内腐蚀管道极限压力拟合公式,并用实际算例对其进行了验证.     

面向语义Web的农业知识表示研究

本文介绍了基于语义Web技术的农业知识表示，目的是将以自然语言形式的农业信息转变为机器可理解形式的农业知识，使得农业知识能够有效的共享和重用。     

对少数民族预科第二课堂汉语教学的认识和思考

通过对第二课堂教学的认识和思考,揭示出第二课堂教学是将理论知识转化为交际技能的过程。学生只有在使用语言的过程中才能学会语言的使用。因此,第二课堂教学在培养学生言语知识和言语能力方面具有非常重要的作用。