查询词典 exterior approximation

A simple radiation model was used to calculate daily changes of the aerosol radiative heating rates and cooling rates in different months. Two-stream approximation, hemispheric constant method, adding method and doubling method were applied in the computation.

摘 要：采用两流近似辐射模式，应用半球常数法近似，采用累加法和倍加法，计算了不同月份大气气溶胶的辐射加热率和减温率的日变化。

By substituting the combustion conditions of both above-mentioned two blast furnaces and laboratory test furnace into the model and with the aid of computer, a close approximation to the practice was obtained.

根据传热和传质原理推导出一组煤粉燃烧的数字模型，将本文中两座高炉和试验室燃烧炉条件代入数字模型用计算机求解得到与实际近似的结果。

It restricted system state in the switch surface by the selection of switch surface and approximation law without accurate system model,and forced the state reach the origin eventually.

其主要特点是控制率主要根据切换面和趋近率来选择，使系统状态约束在切换面两边，最后到达原点，而且控制率与系统模型关系不大。

In order to study the changing process of Barium strontium titanate Ba(subscript xSr(subscript 1-x) TiO3, BST from cubic phase to the tetragonal phase with Ba doping and the ferroelectric characteristic of BST, the total energy of BST with different mole ratio of Ba/Sr when Ba doped was calculated and the fine structure determined, based on general gradient approximation, by means of ultrasoft pseudopotentials plane wave method.

为了研究钛酸锶(SrTiO3， ST)中随Ba的掺入，其晶体从顺电相到铁电相的变化过程及四方相钛酸锶钡Ba(下标 xSr(下标 1-x)TiO3， BST的铁电性。在广义梯度近似下，利用超软赝势平面波方法计算了不同Ba/Sr摩尔比BST的总能量，确定了BST的精细结构。

Unfortunately, however, the simple WKB approximation may be inapplicable to steep-sided profiles (e.g., proton exchanged or epitaxially grown) where, for these almost square cases, it is more appropriate to use a perturbation theory approach.

但不幸的是，简单的WKB近似可能不适用于陡峭片面概况情况下，这些几乎平方米情况下，它更适合使用微扰理论方法。

Based on the chemical evolution model of Milky Way disk. We have establishan infail model without IRA (Instantaneous Recycling Approximation) to studythe star formation history in M31 disk.

本文以银河系化学演化模型为参照，通过建立非瞬时循环假设下的内落模型，详细研究了M31的恒星形成历史。

For problem II, many references have studied it and obtained its common solutions, symmetric solutions, skew-symmetric solutions and its optimal approximation constrained solution, but the representation of its solutions are complicated.

本文首次采用迭代法系统的研究了它求一般解、对称解、反求解约束矩阵方程及其最佳逼近的迭代法的研究对称解、中心对称解、中心反对称解、自反矩阵解、反自反矩阵解、双对称解、对称次反对称解及其最佳逼近问题，并首次成功地解决了它求中心对称解、中心反对称解、自反矩阵解、反自反矩阵解、双对称解与对称次反对称解及其最佳逼近的问题，拓广和改进了已有的研究成果。

In the present work, we have done the following modifications: the finite range Gogny force has been used where the pairing correlation can be considered self-consistently, no symmetry restriction has been imposed where the triaxial and higher multipole deformations can be discussed, no approximation for Hartree-Fock and pairing fields has been done where all the contributions from Gogny force, Coulomb force and the center of mass correction to Hatree-Fock and pairing fields have been included.

Sakata等人首先提出组态指定的参考态方法，并在具有轴对称和旋称对称性的Skyrme-Hartree-Fock平均场中实现了这种新的微观描述，自洽地给出具有不同组态的激发态及随原子核转动频率或形变连续变化的平均场。

With this method, the nextto-leading order Debye screening mass was evaluated within real time hot QCD. Since the gluon damping rate was included self-consistently on the internal line of the self-energy, the infrared divergences were removed without putting by hand in a nonperturbative magnetic mass as a cutoff, and the results are positive and gauge-independent. In addition, the selfconsistent calculation method of the damping rates of the fast moving particles in a QGP was suggested, the self-consitent equations were derived at finite tempeature without infrared divergences, and the approximation solutions were shown. Meanwhile the relaxation times of the gluons and quarks were estimated as τ〓～0.7fm/c and τ〓～1.5fm/c at energy scales of RHIC and LHC.

用这种自洽方法从实时热QCD出发用计算了QGP中次带头阶Debye屏蔽质量，由于自洽包含了胶子自能内线中横胶子的衰减率，克服了红外发散的困难，不必用手加的非微扰磁质量作截断，证明了得到的结果是正定的且规范无关，同时本文给出了QGP中快速粒子衰减率的自洽计算方法，推出了有限温度下快速粒子衰减率的自治方程且红外发散不出现，给出了方程的近似解，并估计了RHIC和LHC能标下胶子和夸克的弛豫时间分别为τ〓～0.7fm/c，τ〓～1.5fm/c。

Ionization Potentials and electron affinities of 103 elements are calculated by density functional theory at local density approximation level and the LDA/AN level with further non- local corrections for exchange and correlation included self- consistently.

应用密度泛函理论的 DFT- LDA、 DFT- LDA/NL和改进的 Slater过渡态方法，把元素的电离能和电子亲合能的计算扩展到周期表的 103种元素。

Objective:To explore the feasibility of laparoscopy in diagnosing and treating of abdominal diseases.

目的：探讨腹腔镜用以诊断腹部外科疾病及选择治疗方案的可行性。

The lifetime of nylon 1010 and nylon 1010/POSS composites decreased with increasing temperature.

热重-红外联用分析表明尼龙1010在氮气气氛下的降解产物主要为小分子的低聚物，POSS并不改变尼龙1010降解产物的组成。