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1.
对对流方程au/at+aau/ax=0,构造了一族两层双参数半显式格式,适当选择两个参数,可以得到精度高稳定性好的半显式格式。 相似文献
2.
潘涛 《广西大学学报(自然科学版)》1994,19(2):105-113
利用特征线方法研究一类具有奇异系数的重特征方程的Cauchy问题,得到保证其古典解存在的一类相容性条件,并导出显式解的表达式。 相似文献
3.
高阶抛物型方程恒稳的显式差分格式 总被引:1,自引:1,他引:1
曾文平 《华侨大学学报(自然科学版)》1998,19(2):124-127
提出解离阶抛物型方程au/at=(1)^m+1a^2mu/ax^2m的一类恒稳定的三层显式差分格式,大大地改进了抛物型方程的网格积分法中格式的稳定性条件,数值例子表明所作的稳定性分析是正确的。 相似文献
4.
提出解高阶演化方程au/at=a(a^2k+1u)/ax^2k+1的两类新的具有高稳定性的三层显式差分格式,较大地改进了同类格式的稳定性条件,数值例子表明,文中所作的稳定性分析是正确的。 相似文献
5.
两类新的高稳定性的三层显式差分格式 总被引:2,自引:1,他引:1
曾文平 《华侨大学学报(自然科学版)》1998,19(3):225-231
提出解高阶发展方程au/at=a(a^2k+1u/at^2k+1)(其中a≠0为常数,k=1,2,3,…)的两为新的具有高稳定性的三层显式差分格式,较大地改进了同类格式的稳定性条件。数值例子表明所作的稳定性分析是正确的。 相似文献
6.
曾文平 《华侨大学学报(自然科学版)》2000,21(1):1-7
讨论高阶演化方程au/at=a(a^2k+1)/(ax^2k+1)(其中a≠0为实常数,k=1,2,3,...)的2层3层显式差分格式,已有格式的精度是O(τ+h)或O(τ+h^2)利用半离散化方法给出一类具有任意阶精度O(τ^p+h^q)(p.q=1.2,...)的显式格式,p=3,4,q=2k.2(k+2)(2层格式)和p=2,4,q=2k,2(k+1).2(k+3)(3层格式)(k=1,2, 相似文献
7.
秦永军 《河南师范大学学报(自然科学版)》1997,25(2):82-83
本给出了两个解SchrOdinger型方程的半显式格式,两格式均能显式计算,且绝对稳定,截断误差为O(τ/h+τ+h^2)。 相似文献
8.
9.
给出一种求解抛物型偏微分方程的变长长显式差分解法,并证明了其收敛性及稳定性,该方法较古典显式差分方法有更大的稳定时间步长。 相似文献
10.
陈近 《重庆邮电学院学报(自然科学版)》1995,7(1):63-73
Fourier变换在偏微分方程理论中占有相当重要的地位。本文通过经典的Fourier变换求解一维、二维热传导方程Cauchy问题的方法,推广Fourier变换到速降函数空间ψ(R^n)和ψ(R^n)上的线性连续泛函ψ'(R^n)广义函数空间上,求出了Cauchy-Riemann方程、热传导方程、常系数椭圆算子方程以及形如δu/δt=p(δ/δx)u的方程的Cauchy问题的基本解。最后引入了Fou 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
14.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献