查询词典 boundary

In the last chapter,we study the control problems of the distributedparameter system governed by a class of higher order pseudohyperbolicequation related to the symmetric regularized long wave equation.we havediscussed the controllability and optimal control problems.we have obtainedcompatibility condition of the constraint when the state is controllable,therepresentation of the optimal control for both the time optimal control problemand the optimal control problem of minimum energy type,and the equationsatisfied by the minimum time.we have shown that the optimal control belongsto the boundary of the admissible control set.

在第六章中，我们研究了与对称正则长波方程相关的一类高阶拟双曲型方程支配的分布参数系统的控制问题。讨论了系统的状态能控性问题和最优控制问题，给出了状态能控时的约束相容性条件，给出了最速控制问题、最小能量型最优控制问题的最优控制表达式和最速时间所满足的方程式，证明了最优控制属于控制集合的边界。

The boundary conditions and the continuity conditions were satisfied by means of artificial springs introduced between the disk and the blades, which greatly simplified the choice of admissible function in Ritz procedure.

模型用Timoshinko梁模拟叶片，用平板模拟轮盘，并在叶片和轮盘间引入弹簧元件模拟叶片和轮盘间的耦合关系，简化了两者间的边界条件和连续性条件。

These problems are classified by the author into three categories: The first are the misinterpretation of the connotations and boundary of the old materialism; secondly, the second note in the work is often misinterpreted as belonging to only epistemology, though it, in fact, involves both generative theory and ontology; thirdly, the progressive relationship between "interpreting the world" and "transforming the world" is mistaken as adversative relation.

笔者认为这些问题主要表现为：一是对旧唯物主义内涵及其域限理解上的偏误；二是把《提纲》第二条仅局限于认识论领域，而无视其生成论、存在论的维度；三是把"解释世界"与"改变世界"间的递进关系误认为是转折关系。

Based on the analytical theory of aeolotropy,thermal distortion and temperature field distributions of Nd∶YVO4 crystal with rectangular section were investigated when the third thermal boundary condition was considerated.

以各向异性半解析热分析理论为基础，研究矩形横截面Nd∶YVO4激光晶体在有第三类热边界条件工作时，激光晶体温度场分布和晶体抽运面热形变分布。

The main factors affecting the soil-structure interface behaviors were found experimentally and theoretically, including: 1 the thickness of the interface that is five to six times the average grain size of the soil; 2 the aeolotropy of interface, which is responsible for anisotropic response of the stress-strain response of the interface; 3 two physical states, including crashing and compression of the soil near the structure surface, which govern the stress-strain response of the interface strongly; 4 two shear deformation components due to sliding and constraint of the structure surface relative to the soil respectively, which forms the deformation of the interface; 5 the volumetric strain due to dilatancy, which is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. 4. A unified constitutive model of the interface, based on new elasto-plasticity damage theory, was developed. It was confirmed to be effective for the conditions considering monotonic and cyclic shearing, coupling effect of shear and volumetric strains, evolution of physical state, micro-structure aeolotropy of the soil and the resulting aeolotropy of the interface as well as the three normal boundary conditions stated above. 5. 2D and 3D finite element formulations of the present model were derived and incorporated into the FEM codes. They were applied to the evaluation of practical engineering problems with different typical interfaces between soil and structure. The new model was shown to be reasonable and effective.

确定了粗粒土与结构接触面厚度约为5～6倍的平均粒径，首次揭示了接触面的细观结构异向性以及由此所引起的宏观剪切异向性，发现了在单调和往返剪切荷载作用下土颗粒破碎和剪切压密两种物态变化机制共同支配着接触面力学性质的变化，通过细观分析证实了接触面的变形可分解为一般同时发生的土与结构交界面上的滑移变形以及结构面位移约束范围之内土体本身的剪切变形两部分，观测到接触面受剪时表现出明显的相对法向位移，并可分解为可逆性和不可逆性两个分量；(4)建立了第一个能够统一地描述单调与往返剪切特性、剪应变与体应变耦合特性、细观结构和宏观剪切异向性以及土颗粒破碎等物态变化特性的土与结构接触面弹塑性损伤本构数学模型，并采用多种法向边界条件复杂加载路径的试验成果验证了新模型的合理性和有效性；(5)提出了新模型的二、三维有限元格式并结合实际边值问题进行了应用计算分析，比较了不同接触面本构模型对计算结果的影响，证实了新模型及其有限元格式不仅能够合理地描述土与结构接触面的主要力学特性，还能够较好地反映土体与结构物在接触面处的滑移、脱开等不连续现象。

The capture of service roads outside the regions described above and inside the aerodrome boundary is optional.

在上述区域以外的在机场边界上方或以内的服务道路的录入是可选的。

An aerodynamical urban canopy scheme is incorporated into the fine town boundary layer model. The scheme contains drag effect of urban buildings on flow and effect of building morphology on urban turbulent activity and momentum transfer.

文中将建筑物动力冠层方案引入到城市边界层精细模式中，该方案描叙了城市地区建筑物对气流的拖曳作用以及建筑物形态对城市地区湍流活动动量输送的影响。

The effects of magnitude and distribution of the electromagnetic force on the flow around the aerofoil were investigated. The results show that the electromagnetic force with large magnitude and concentrated distribution on the surface of aerofoil is advantageous to eliminate vortex structures and boundary separation, and therefore to increase the lift-drag ratio.

同时对不同电磁力大小和分布影响翼型表面边界层流动的规律进行了探讨，其结果表明，较大的电磁力和更加集中于翼型表面的电磁力分布可以很好地消除涡结构，抑制边界层分离进而达到提高升阻比的效果。

Boundary flow around an aerofoil controlled by streamwise electromagnetic force was simulated numerically at the low Reynolds number.

在低Re数条件下，对流向电磁体积力影响翼型体表面边界层流动过程进行了数值模拟。

Aerophysics of Atmospheric Boundary Layer .

大气边界层物理学。

We squeezed together on a train to Beijing, like sardine fish.

在去北京的火车上我们大家挤在一起，像沙丁鱼似的。

Any diamond with a natural body colour strong enough to be attractive, rather than off colour.

任何身体天然彩色钻石具有强烈的吸引力不够，而是过颜色。