数值

In this paper, the structure characteristics of atmospheric boundary layer have been studied over Lanzhou in winter by combining numerical simulation method with analysis of the data which was observed by sounding balloon during the collaborative project "Study on air pollution and countermeasure in Lanzhou" supported by Gansu Government and Chinese Academy of Sciences.

本文利用甘肃省政府和中国科学院的科技合作项目"兰州市大气污染及对策研究"所获得的系留气球探空资料，并且结合数值模拟方法，对兰州市冬季大气边界层温度场特征进行了对比分析，结果表明：在没有特殊天气过程的典型冬季代表性时段，山谷城市兰州逆温边界层结构无论白天或夜间都存在，而且经常出现多层逆温和白天的脱地逆温情况，只有当冷空气过境时，逆温现象才减弱或消失；与观测结果相比较可以看出，数值模拟结果基本上反应了温度场的主要特征。

The main results are as follows:（1） the distance a sounding balloon drifts during operation is a lot longer than that is accepted as a horizontal resolution by present numerical models;（2） the positioning scheme presented for sounding balloons is basically applicable to a resolution of 10 km × 10 km;（3） on the whole, the position correction leads to the fact that the resulting analytic increment field is one order of magnitude smaller than the original;（4） analysis of the model predictions shows that soundings, when positioned,leveled soundingswould improve predictions.

结果表明：探空气球在施放过程中的漂移距离远远超过目前数值模式可取的水平分辨率；所设计的探空气球定位方案对水平分辨率为10km 10km的数值预报模式基本是可用的；总的来讲，位置订正对分析增量场的改变与原分析增量场相比小一个量级。模式预报结果显示，探空资料的定位使降水预报效果得到了改善。

The valve of polytropic specific heat capacity is depending on polytropic exponent n.

多变比热容的数值仅决定于多变指数n 的数值。

The specific heat capacity and thermal conductivity of wall material have a remarkable effect on the north wall temperature distribution.

温室内土壤温度和气温的实验结果与数值模拟结果相符合，从而表明所建立的传热模型和数值计算结果是正确的与可靠的。

After the brief retrospect of spectral methods applied to get the numerical solutions of partial differential equations, the Walsh spectral methods are extensively studied. A new method of designing the "derivate operator" and a new Walsh spectral method based on quasi-Walsh order are proposed, which primarily prove the special uses of it.

回顾了数值求解偏微分方程的谱方法，比较深入地考察了数值求解偏微分方程的Walsh谱方法，提出了一种新的设计"求导算子"的方法，基于这样设计出来的"求导算子"，提出了一种新的基于类Walsh序的Walsh函数的Walsh谱方法，初步验证了这种序的特殊价值。

The following are the major work in this thesis which has been studied and still needs to be studied further in the future: 1 An improved adjoint variational method is developed, thus it can be applied to the LAGFD-WAM Wave Numerical Model for data assimilation; 2 A linear evolution equation of spectral perturbation is derived in order to analyze its increasing or decreasing mechanism.

本论文主要完成了以下几个方面的研究： 1）建立了推广形式的共轭变分同化方法，使之能够应用于LAGFD-WAM海浪数值模式； 2）导出了扰动谱线性演化方程，分析了扰动谱增长、衰减机制，考察了涌浪情况下扰动谱的持续时效问题及风浪情况下扰动的演变过程； 3）利用波谱共轭方程初步分析了同化模型中距离泛函的敏感性及敏感区域空间分布； 4）将推广的共轭变分方法应用于海浪谱能量平衡方程，建立了连续形式的海浪同化模型，特别是严格导出了风输入、破碎、底摩擦、波波非线性相互作用和波流相互作用各源函数的共轭源函数表示式； 5）分别进行了波谱层次上和有效波高层次上的同化试验，并对数值结果进行了分析。

Applying the boundary condition in the interface between the uniaxial anisotropic medium and free space, the surface of the conducting sphere, the expansion coefficients of electromagnetic fields in terms of spherical vector wave function in uniaxial anisotropic medium are obtained, and then the expansion coefficients of scattering fields and radar cross sections can be obtained.

通过矩阵方程的求解和球B(来源：e3ABC论文网www.abclunwen.com)essel函数的大宗量渐进表达式，我们给出了各向异性单轴介质球结构对平面波电磁散射的数值计算结果，并和其他的数值计算结果进行了比较，其结果正如我们所预料的一样，达到了预期的结果。

Gridless smooth particle hydrodynamic numerical technique of AUTODYN-2D hydrocode is used to simulate the impact behavior of spherical and cylindrical space debris on-orbit impacted at a velocity of 10km/s.

采用AUTODYN-2D无网格SPH数值技术，对碰撞速度10km／s下的球形及柱状空间碎片在轨碰撞超高速作用行为进行数值模拟，给出了不同节点处的速度变化规律。

On the basis of the model, the friction force in each meshing point on the spiral bevel gear surface covered by silver film is presented by numerical method. In addition, the result is indirectly proved by experiment.

用数值法求解了弧齿锥齿轮镀银齿面之间各啮合点处的摩擦系数；以试验方法对数学模型的正确性进行了间接验证；通过详尽的数值计算探讨了银层厚度、刀盘直径、基体硬度等参数对摩擦系数的影响。

Furthermore, the statistical characteristics of the flow fields at the stator passage are obtained from the data of SPIV measurement, and the turbulence kinematic energy fields and Renold Stress fields are analyzed in primary at both design and near stall conditions.

从SPIV测量结果及CFD数值模拟结果来看，当前的CFD数值模拟技术在模拟真实压气机时，模拟结果总体趋势是正确的，但在具体流动细节上，其计算精度和可靠性还有待于进一步提高。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。