自然边界条件

Part II, the artificial boundary condition and its numerical methods based on natural boundary reduction for a hyperbolic initial boundary value problem in an infinite domain with a concave angle is investigated.

第二部分，研究一类具有凹角的无界外区域的双曲型初边值问题基于自然边界归化的人工边界条件及其数值方法。

In fact, for interior problem, solution of the direct boundary integral equation always exists.

事实上，对内边值问题，第一类Fredholm 直接边界积分方程的可解性条件是自然得到满足的，本文对此做了验证。

Because the method employs the technique along the characteristics to discretize the convective term and it is unnecessary to determine the boundary condition of the vortex ahead of time, it is very convenient to solve the Navier-Stokes equation and natural convection problem.

该方法对对流项仍采用沿特征线离散技术，并且不需要事先确定漩涡度的边界条件，从而可以方便地求解流函数-漩涡度形式的Navier-Stokes方程及自然对流问题。

More than 30 kinds of meshfree methods are reviewed in this paper in the light of weighted residual method, and different meshfree methods can be viewed as different forms of weighted residual method and/or with different approximation functions. Various kinds of meshfree approximate schemes are presented in detail, including moving least square approximation, kernel and reproducing kernel approximation, partition of unity approximation, radial basis approximation, radial point interpolation and natural neighbor interpolation.

详尽介绍了各种无网格近似方案(包括移动最小二乘近似、核近似和重构核近似、单位分解近似、径向基函数近似、点插值近似、自然邻接点插值近似等)和无网格法中常用的各类加权余量法(伽辽金格式、配点格式、局部弱形式、加权最小二乘格式和边界积分格式等)，并讨论了数值积分方法和边界条件的处理等问题。

The underwater enclosure was built along the boundary of target water body and the lake bottom sludge was filled into the enclosure by twisting-suction dredging ship according to designing elevation for the purpose of formation of slope riffle, which will improve natural condition of littoral zone of lake, and create favorable habitation condition for ecological restoration in littoral zone of lake.

文章介绍最新开发的湖滨陡坎沿岸水域基底修复技术，主要采用人工方法在需要进行大型水生植物群落恢复的湖滨陡坎沿岸的水域实施基底修复工程措施，在目标水域边界构筑水下围埝，采用绞吸式挖泥船将疏浚的湖泥按设计高程要求吹填至基底修复工程区内，形成缓坡浅滩，改善湖泊沿岸带自然条件，为湖泊沿岸带生态修复创造良好的生境条件。

He and Nina moved to California and lived at 2005 Ivar Street, Apt.

他和Nina搬到加州，并在2005年伊瓦尔街，公寓生活。

Droperidol （ potently inhibits transfected HERGchannels and this is the probable mechanism for QT prolongation.

氟哌利多有效地抑制了转染的 HERG 钾通道，可能是 QT 间期延长的机制。