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对四阶抛物型方程构造一族新的含参数三层显式差分格式,它包含了DuFort-Frankel型格式,适当选取参数时,可得到一个新的高精度显格式,其截断误差达到O[(△t)^2 (△x)^6],其稳定条件为γ=△t/(△x)^4≤31/360,优于文[1]的稳定条件,当选取γ=1/252时,其截断误差高达O[(△t)^2 (△x)^8],数值例子表明该格式是有效的。 相似文献
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陈世平 《泉州师范学院学报》2004,22(4):6-8
对四阶抛物型方程构造一族新的含双参数三层隐式差分格式,并证明该族格式对任意非负参数都是绝对稳定,并且其局部截断误差达到O[(△t)^2 (△x)^8],通过数值例子表明该格式是有效的. 相似文献
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陈世平 《泉州师范学院学报》2002,20(6):1-4
对四阶抛物型方程构造一族新的含参数隐式差分格式,它包含了许多名格式,适当选取参数时,可得到一个高精度恒稳格式,其截断误差达到O[(Δt)^2 (Δx)^6)],数值例子表明该格式是有效的。 相似文献
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用含参数的差分方程逼近微分方程的方法,构造了Schroedinger方程的一个三层高精度隐式差分格式:1/12τ(3/2uj 1^n 1-2uj 1^n 1/2uj 1^n-1) 5/6τ(3/2uj^n 1-2uj^n 1/2uj^n-1) 1/12τ(3/2u(j-1)^(n 1)-2u(j-1)^n 1/2u(j-1)^(n-1)=i[u(j 1)^(n 1)-2uj^(n 1)- u(j-1)^(n 1)]/h^2,其截断误差阶可达到O(τ^2 h^4),并用Miller定理证明了其稳定性,数值例子表明该格式是有效的。 相似文献
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本文构造了一个解Schroedinger方程的三层显式差分格式.格式绝对稳定,截断误差为O(τ^2 h^2). 相似文献
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利用二阶微商的四阶精度紧致差分逼近公式,给出解Schroedinger方程的精度为O((1-2θ)τ τ^2h^4)的一个新的加权差分格式,当1/2≤θ≤1时格式绝对稳定.特别地,当θ=1/2时,文章所给出的差分格式可高达四阶精度,数值结果与理论分析相一致. 相似文献
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文章基于Pad6逼近,针对四阶抛物型方程周期初值问题。构造了一个无条件稳定的高精度的两层隐格式。它的局部截断误差为0((△t)^2+(△x)4),△t与△x分别为时间和空间步长.误差分析和数值实验均表明,构造的格式比Saul’ev构造的格式精度要高10^-4 - 10^-5阶.从精度及稳定性方面考虑,所构造的格式也比文[4]的显式格式要好. 相似文献
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马小宁 《新乡教育学院学报》2005,18(4):76-76
构造了一个二维热传导方程的两层显式格式,截断误差为O(△t △x2),稳定性条件为r=t/x2=t/y2<1/2,优于同类的其它显式格式。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献