查询词典 boundary layer

This invention discloses a preparation method for anti-corrosion rare earth magnet material characterizing that it takes the optimized grain-boundary phase design as the starting point on the basis of a dual alloy method to select Nd base alloy with high crystal forming ability as the assist alloy and reduces the temperature of the press mold blank in a quartz container to room temperature from over grain-boundary phase melting point with the water extraction way to get enough cooling rate and guarantee the non-grain-boundary phase, compared with the material of the same composition prepared by ordinary method, the weightlessness of this invented material reduces over 30% after testing the weightlessness of the material by laying it for 96 hours under 121deg.C, 2 atmosphere and 100% humid environment to show the advanced performance of anti-corrosion.

本发明公开了一种耐腐蚀稀土永磁材料的制备方法，其特征是它在双合金法制备工艺的基础上，以优化晶界相设计为出发点，选取具有较高非晶形成能力的Nd基合金为辅合金，并在烧结回火时将置于耐高温石英容器中的压型坯件，从晶界相熔点以上以水淬冷却的方式降温至室温，以达到足够的冷却速率，确保得到非晶晶界相，根据本发明制得的耐腐蚀稀土永磁材料，通过测量在121℃、2个大气压以及100％湿度环境下放置96小时后材料的失重情况，结果显示本发明得到的材料与常规方法制备的相同成分的稀土永磁材料相比失重减少了30％以上，充分证明其具备了更优越的耐腐蚀性能。可广泛应用于电子、汽车、计算机、电力、机械、能源、环保、国防、医疗器械等领域。

This is a kind of evolutionary elliptic free boundary problems, in which the free boundary changes with time and at each fixed time the unknown function satisfies a boundary value problem for an equation of elliptic type.

详细本文分两部分。第一部分讨论拟定常电加工问题。这是一类发展型的椭圆自由边界问题，其自由边界依赖于时间的变化而不断演化，在每一固定时间，未知函数满足椭圆型方程的边值问题。

Using the method of blow up lower and upper solutions, the existence and boundary behavior of positive boundary blow up solutions for some elliptic systems of competitive type with singular weight functions are obtained, here the singular weight functions are permitted to be bounded in some parts of the boundary, and to go to infinity or even oscillate in other parts.

利用爆破上、下解方法，本文建立了带奇异权函数的竞争型椭圆方程组正的边界爆破解的存在性和边界行为，这里奇异权函数可以在边界的某一部分有界，而在其他的部分趋于无穷或者震荡。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work.Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。2。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work. Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted. It was found in our drop tests that the root cause of lead-free solder joints under drop impact was the combined effect of mechanical shock and PCB bending vibration.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。

In order to develop this local property,this paper presents a method,which uses Fourier Series to approximate the boundary shapes of the shafts with periodic boundary of cross section,and uses the conformal mapping in Theory of Function of a Complex Variable to make the complicated boundary shapes of the shafts map a unit circle.Thus elastic theory can analyze...

本文提出一种方法，其实质是：采用富里埃级数来逼近横截面呈周期性变化边界的轴类零件的边界形状；并应用复变函数论中保角映射原理，将零件复杂的边界形状映像成单位圆，从而使弹性理论可以分析和计算复杂边界轴类零件的应力场；再通过留数的求解实现保角映射的反变换。

Remove row and column' and 'put a big number' have been used for the first boundary;a continuous Regional Identification Function is used on the basis of non-variant nodal virtual flux method for the free surface boundary;Gauss formula is used to make the curved surface integral of the free surface boundary transformed as the difference between volumn integral and other curved surface integral to calculate the integral item on boundaries, which avoiding finding the position of free surface, while the continuous Regional Identification Function is applied to calculate volumn integral and surface integral;Crout and PCG method is used for solusion.

对于已知水头边界，采用"去行去列法"和"置大数法"进行处理；对于自由面穿过的单元，在固定网格节点虚流量法的基础上，引入连续的区域识别函数；对于非稳定渗流中自由面边界积分项，采用高斯公式将求自由面的面积分转化为求体积分与其他面积分之差，避免了求自由面的具体位置，同时在计算体积分和面积分时采用连续的区域识别函数；在解法上，采用直接解法和PCG法。

Finally, in the third section, by constructing some functional which similar to the conservation law of evolution equation and the technical estimates, we prove that in the inviscid limit the solution of generalized derivative Ginzburg—Landau equation converges to the solution of derivative nonlinear Schrodinger equation correspondently in one-dimension; The existence of global smooth solution for a class of generalized derivative Ginzburg—Landau equation are proved in two-dimension, in some special case, we prove that the solution of GGL equation converges to the weak solution of derivative nonlinear Schr〓dinger equation; In general case, by using some integral identities of solution for generalized Ginzburg—Landau equations with inhomogeneous boundary condition and the estimates for the L〓 norm on boundary of normal derivative and H〓 norm of solution, we prove the existence of global weak solution of the inhomogeneous boundary value problem for generalized Ginzburg—Landau equations.

第三部分：在一维情形，我们考虑了一类带导数项的Ginzburg—Landau方程，通过构造一些类似于发展方程守恒律的泛函及巧妙的积分估计，证明了当粘性系数趋于零时，Ginzburg—Landau方程的解逼近相应的带导数项的Schr〓dinger方程的解，并给出了最优收敛速度估计；在二维情形，我们证明了一类带导数项的广义Ginzburg—Landau方程整体光滑解的存在性，以及在某种特殊情形下，GL方程的解趋近于相应的带导数项的Schr〓dinger方程的弱解；在一般情形下，我们讨论了一类Ginzburg—Landau方程的非齐次边值问题，通过几个积分恒等式，同时估计解的H〓模及法向导数在边界上的模，证明了整体弱解的存在性。

O the system should be put into an expending system to be dealt with, which includes the original system, the environment system and the band boundary. There are various complex interactive relationships between the original system and the environment system in an expending system; therefore the band boundary becomes a gradational boundary.

AR系统理论借用了生物系统中的许多重要概念，比如感知、反应、捕获、游离等来研究这类复杂系统的演化问题，认为开放系统的复杂性主要是由系统与环境之间的相互作用关系产生的，而这种相互作用关系最集中地体现在系统边界上，因此必须把系统、环境以及边界三者一起放到一个更广泛的全系统中进行处理。

Boundary element method is a kind of numerical algorithm on boundary; it is based on the boundary integral equation and employs the element discretization technique.

边界元属于边界型的数值方法，它是以边界积分方程为数学基础，同时采用了有限元法的单元离散技术。

World War II: Battle of Saipan - Americans take Saipan.

1944年的今天，美国在塞班战役中拿下塞班岛。

When the scorner, the rejecter of truth, has become presumptuous; when the routine of work in the various money-making lines is carried on without regard to principle; when the student is eagerly seeking knowledge of everything but his Bible, Christ comes as a thief.{DA 635.3

当讥诮和拒绝真理的人，到了任意妄为时，当追求财利者罔顾按道义经营谋利时，当学人正在兢兢业业地研究各种知识，而单把圣经丢在一边时，基督要像贼一样来临。