截面

A MoSi2 coating on C-103 niobium alloy was prepared by packing cementation, and the microstructures of the oxidized and unoxidized coatings were analyzed by XRD, SEM and EDS techniques. The formation mechanism of the silicide coating was investigated. The results show that the silicide coating is formed by reactive diffusion and the silicification process obeys parabolic relation.

采用包渗法在C-103铌合金基体上制备MoSi2涂层，通过X射线衍射、扫描电镜和能谱分析等手段研究涂层表面、截面形貌以及氧化后涂层结构变化，并分析硅化过程中涂层的形成机理。

This method is built at the basis of similative of the mathematic relation between the torsion problem of pole and elasticity membrane which is under the action of equal side pressure and exaggerates tight around.

为了解决较复杂截面杆件的扭转问题，特提出薄膜比拟法。该方法是建立在柱体扭转问题与受均匀侧压力而四周张紧的弹性薄膜之间数学关系相似的基础上。

In the study of the stochastic chaos in simple pendulum, the random Melnikov process is derived and the mean-square criterion is used to determine the threshold amplitude of the bounded noise excitation for the onset of the chaos or random chaos in the system. For the coupled simple pendulum and harmonic oscillator, the Melnikov function is used to determine the condition for the onset of chaos in the case of Hamiltonian perturbations. In the case of non-Hamiltonian perturbation, the generalized random Melnikov process and mean-square criterion are used to determine the threshold amplitude of the bounded noise for the onset of random chaos.

在随机混沌研究中，应用随机Melnikov过程的均方准则研究了单摆在有界噪声激励下发生混沌或随机混沌时有界噪声激励的临界幅值；对于耦合的单摆-谐振子系统，先用Melnikov函数研究了在哈密顿扰动下发生混沌的必要条件；然后用推广的随机Melnikov过程方法研究了在非哈密顿扰动下发生随机混沌的必要条件；用最大Lyapunov指数及Poincaré截面方法结果与上述理论结果作了对比。

The frequency shifts and relative intensity configuration of multidegree stokes spectrum were measured and a simple analysis of spectrum characteristics using the concepts of effective scattering cross-section and differences of vibrational e...

测试了两类光纤的多级Stokes谱的频移分布与相对强度分布，并从等效散射截面的相对大小和赈动能级差的相对大小对话的特征进行了初步的分析。目的是在实验研究的基础上探索刊用这两类常用光纤构成光纤拉曼激光器以及利用光纤拉曼散射谱的可能性。

In order to decrease the number of repeat calculation, the contours can be divided into a series of simply connected region. Blanking method will be used for the contour's scanning lines to generate scanning lines of the layer by the unit of simply connected region.

为了减少重复计算的次数，将截面的所有轮廓划分为一系列的单连通区域，将处理后的各轮廓的扫描线，以单连通区域为单位应用消隐法生成层扫描线。

The number and distribution of the singular points of streamlines in the cross section of steady flow through a curved tube are discussed by using the method of topological structure analysis.

利用拓扑结构分析方法，分析了弯曲圆管内定常流在横截面上流线的奇点个数及分布规律，给出了二次流的漩涡数目由 2个变为 4个，流态结构发生分叉现象的理论判据·进而，利用Galerkin方法，得到了弯曲圆管内定常流的流函数和轴向速度的半解析表达式，给出了流态结构发生分叉现象的临界Dean数，所得结果与理论判则一

With the increase of angle of attack, the types and connection models of singular point will be changed.

随着降落伞迎角增大，奇点类型和奇点间的连接方式将发生改变，降落伞物面附近的涡环里将出现极限环，截面流场中将出现新的鞍点和结点。

Through the assimilating and analyzing the construction materials and the design of reinforced concrete arch bridges with long span from both domestic and abroad, the thesis studies the effect of the arch axis geometry, rise-span ratio, arch ring section and spandrel structures, as well as the ultimate bearing capacity and stability of the entire bridge on the design of reinforced concrete arch bridge. In addition, in consideration of construction, the thesis also studies the applicability of different construction methods such as cable crane system, stiffened skeleton system, swing construction system and cantilever construction system and correspoindingly economica spans and their applications of the reinforced concrete arch bridges.

本论文通过对国内外大跨径钢筋混凝土拱桥的设计、施工资料的收集及其出现问题的分析，从设计角度研究了拱轴线形、矢跨比、拱圈截面及拱上构造、全桥极限承载能力及稳定性对钢筋混凝土拱桥设计的影响；从施工角度研究了缆索吊装法、劲性骨架法、转体施工法、悬臂施工法等不同施工方法的钢筋混凝土拱桥的经济适用跨径及其适用条件。

Base on summarizing the development state of assembly skew hollow slab bridge, the research content of this dissertation has been determined. Taking Tuan Shan River Bridge, in Hubei province, China, as an example, the finite element method of space slab shell programmed in Ansys Parameter Design Language is adopted to analyze the elastic properties. By calculating the internal force influence surface of assembly skew hollow slab bridge, the internal force-controlling section is attained.

本文在对装配式斜交空心板桥的发展现状进行了详尽的综述后，确定了本文的研究内容，以团山河大桥为工程背景，采用ANSYS提供的参数化语言APDL，用空间板壳有限元法，对装配式斜交空心板桥弹性阶段的受力特性进行全面分析，计算了装配式斜交空心板桥的内力影响面，得到内力控制截面。

Based on it, the research content of this dissertation has been determined. Tuan Shan River Bridge is selected as an example and APDL is used to analyze the elastic properties. After calculating the internal force influence surface of assembly skew hollow slab bridge, the internal force-controlling section is attained; the transverse distribution of internal force is studied and the transverse distribution coefficient is parametric analyzed. Based on the results, relation formula of transverse distribution coefficient between skew and perpendicular bridges are fitted. Practical calculation method for the internal force calculation of assembly skew hollow slab bridge is offered. Some conclusions are drawn from comparing and analysing the internal force, bearing reaction and deformation of both assembly and monolithic skew slab bridges.

本文对装配式斜交空心板桥的发展现状进行了综述，从此出发，确定了本文的研究内容，以团山河大桥为工程背景，采用ANSYS 提供的参数化语言APDL，对装配式斜交空心板桥弹性特性进行全面分析，计算了装配式斜交空心板桥的内力影响面，得到内力控制截面；同时计算了内力的横向分布影响线和横向分布系数，并对内力横向分布系数进行了参数分析；基于参数分析的结果，拟合了装配式斜交空心板桥与对应正交桥内力横向分布系数的关系式，为装配式斜交空心板桥的内力计算提供了实用计算方法；对比分析了装配式斜板桥与整体式斜板桥的内力、支座反力以及变形特点，得出了一些有益结论。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。