exam1

说明：  主要用于计算最常见的二维材料石墨烯纳米带的能带结构(It is mainly used to calculate the energy band structure of graphene nanoribbons, the most common two-dimensional material.)

目前三维的混凝土建模很少见，随机球形骨料在受限空间（球体）随机分布模型,本人自己编写，具有原创性。动画显示建模过程。三种粒径不同的骨料随机分布。模拟混凝土材料的过程。有助于后续有限元计算。(Random spherical aggregate in the restricted space (sphere) random distribution model, I write it myself, with originality. Animation shows the modeling process. Three kinds of aggregates with different particle sizes are randomly distributed. The process of simulating the concrete material. It is helpful to the subsequent finite element calculation.)

重磁异常正演方法，是在给定地质体的形状大小、空间位置及物性参数的条件下，求它外部空间任意点上的物理场值。(The forward method of gravity and magnetic anomaly is to calculate the physical field value at any point in the outer space of a given geological body under the condition of its shape, size, space position and physical parameters.)

求解椭圆型方程生成二维翼型网格，并采用逐线松弛迭代技术求解了二维翼型绕流，这是CFD计算中的典型例子，是cfd初学者的很好的学习例子。(Solving elliptic equations, generating two-dimensional airfoil mesh, and using line relaxation iterative technique to solve the two-dimensional airfoil flow, which is a typical example of CFD calculation, a good example for new CFD learner.)

用数值求解一阶贝塞尔函数的前10个零点并作出曲线(Numerical solution of the first-order Bessel function of the top 10 zero point and make a curve)

根据高斯光束的特性，在matlab中作出束腰半径为0.5mm的高斯光束在束腰处的三维光强分布图。(According to the characteristics of the Gauss beam, the three-dimensional intensity distribution of the Gauss beam with the waist radius of 0.5mm at the waist is made in MATLAB.)

说明：  一个基于有限元方法的平面问题求解器，支持网格类型为二维四边形四节点单元和四边形八节点单元的有限元网格： 前处理——用Abaqus建模编号并导出数据 在Matlab中读取数据文件 计算单元刚度矩阵（采用高斯积分），组集结构刚度矩阵 组集结点载荷向量，引入位移边条 求解结点位移，单元应力应变 后处理——绘制应力应变位移云图，与Abaqus结果对照(A plane problem solver based on finite element method)

说明：  超短脉冲是谐振腔中增益与损耗达到平衡、色散与非线性达到平衡时所产生的。啁啾型脉冲在光纤中传播，因色散作用及各种非线性作用谱线被展宽。(Ultra-short pulses are generated when the gain and loss of the cavity are balanced, and the dispersion and nonlinearity are balanced. Chirped pulses propagate in optical fibers, and their spectral lines are broadened due to dispersion and various non-linear effects.)

说明：  通过matlab仿真偶极子声场的指向性，在极坐标下作图画出指向性(The directivity of dipole sound field is simulated by MATLAB, and the directivity is drawn in polar coordinates)

R-R分布函数的源码，用来测试颗粒物浓度时亲测可用，值得下载(The source of R-R distribution function is used to test particulate matter concentration, so it can be downloaded, and is worth downloading.)