精确解

Applying the concept of equivalent negative stiffness of axial forces, the approximate formula for the critical load of the system is suggested, and compared with theoretical results.

对伸臂位于项部的两层框架—筒体模型进行精确位移法分析，得到了结构有侧移失稳的临界荷载精确解。

Following which, we give the error estimates between the approximate solution and the exact solution.

接着，我们又给出了方程近似解与精确解之间的误差估计。

Nonlinear wave system; Exact solution; Approximate solution; Soliton; Riccati equation method; Turing machine; Computable function

非线性波系统；精确解；近似解；孤立波； Riccati方程方法；图灵机；可计算函数

MVFK8vP7Ge+Uu0 Nonlinear wave system; Exact solution; Approximate solution; Soliton; Riccati equation method; Turing machine; Computable function

非线性波系统；精确解；近似解；孤立波； Riccati方程方法；图灵机；可计算函数

Based on the modal superposition method and the exact solution of beam nature vibration, the motion equations of the simply supported and continuo...

基于模态叠加法和梁固有振动的精确解，建立了移动荷载作用下简支梁和连续梁的运动方程；利用样条最小二乘法逼近桥梁应变响应，由样条数值微分求得响应导数；再通过Tikhonov正则化方法结合奇异值分解技术得到了荷载识别的正则解。

The staircase-like increasing of 〓 obeys an exact differential gap equation, which can be solved analytically.

s的阶梯式增长服从一个精确的隙距方程，该方程有精确解。

If the solution of the equation is existent and unique, the exact solution of the equation is given.

如果该方程的解存在且唯一，文章给出了该方程的精确解的形式表示。

By using the ansatz method, we get an exact quantum solution of the system.

通过试探解方法，得到系统的量子力学精确解。

This dissertation studies some topics in soliton and integrable system,which mainly include as follows:exact solutions especially travelling wave solu-tions and solitary wave solutions,Painlevēproperty,transformation,similarity reduction,symmetries and their Lie algebra structure,generation ofsoliton hierarchy and their zero curvature representation,Hamiltonian struc-ture,Lax or Liouville integrability,nonlinearization of Lax pairs,applications ofWu's method and symbolic computation.

本文研究内容涉及到孤立子和可积系统的多个方面：精确解特别是行波解和孤波解，Painlevē性质、变换、相似约化、对称及其Lie代数结构、孤子族的生成及其零曲率表示，Hamilton结构，Lax和Liouville可积性、Lax组的非线性化以及吴方法和符号计算在上述研究中的应用。

Based on them, we calculated precisely some enegy levels of P-wave and D-wave of a helium atom, presented and proved the general interdimensional degeneracies for a quantum N-body system, derived the general spherical spinor functions and the exact solution to the Dirac equation for the hydrogen atom, and proved uniformly the Levinson theorem for the Dirac equation in D-dimensions.

在此基础上，我们精确计算了氦原子P波和D波若干较低能级，建立和证明了量子N体系统不同维数状态间最普遍的简并，推导出任意 D 维空间广义球旋函数和Dirac方程氢原子的精确解，统一地提出和证明了任意 D维空间Dirac方程Levinson定理的一般形式。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。