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1.
研究奇异三阶m点边值问题:u(t)=f(t,u(t),u′(t),u″(t))+e(t),0t1,u(0)=u′(0)=0,u′(1)=∑m-2i=1αiu′(ξi),C1[0,1]解的存在性。这里函数f:[0,1]×R3→R满足Carath啨odory条件,t(1-t)e(t)∈L1(0,1),αi∈R,ξi∈(0,1),(i=1,2,…,m-2)且0ξ1ξ2…ξm-21是给定常数。主要结果的证明基于Leray-Schauder延拓定理。  相似文献   

2.
应用Leray-Schauder延拓定理,得到了二阶常微分方程多点边值问题x″(t)=f(t,x(t),x′(t)) e(t), t∈(0,1)αx(0)-βx′(0)=∑m-2i=1aix(ξi), γx(1) δx′(1)=∑n-2j=1bjx(τj)解的存在性,其中f:[0,1]×R2R满足Caratheodory条件,e(·)∈L1(0,1),ai,bj∈R,ξi,τj∈(0,1),i=1,2,…,m-2,j=1,2,…,n-2,0<ξ1<ξ2<…<ξm-2<1,0<τ1<τ2<…<τn-2<1.  相似文献   

3.
m点边值共振问题的上下解和拓扑度   总被引:2,自引:0,他引:2  
研究拓扑度与二阶m点边值共振问题u″(t)=f(t,u(t),u′(t)),t∈(0,1)u′(0)=0,u(1)=∑m-1i=1aiu(ξi)的上下解之间的关系.其中f[0,1]×R2R连续,ai和ξi∈[0,∞)为满足∑m-1i=1ai=1及0=ξ1<ξ2<…<ξm-1<ξm=1的给定常数.  相似文献   

4.
讨论下述带参数的三阶m-点边值问题u(t)+f(t,u(t),u′(t))=0,t∈(0,1),u(0)=u′(0)=0,u′(1)-∑m-2i=1aiu′(ξi)=λ,其中ai≥0(i=1,2,…,m-2),0ξ1ξ2…ξm-21,∑m-2i=1aiξi1,λ≥0为参数。当f满足超线性或次线性条件时,对适当的λ≥0,获得了上述问题单调正解的存在性与不存在性。所用主要工具是Guo-Krasnoselskii不动点定理。  相似文献   

5.
考察了非线性方程m点边值问题u″(t) a(t)u′(t) b(t)u(t) f(t,u)=0,0≤t≤1,u(0)=0,u(1)=∑m-2i=1αiu(ξi),的正解的存在性与多解性.设a∈C[0,1],b∈C([0,1],(-∞,0));设1(t)为线性方程边值问题u″(t) a(t)u′(t) b(t)u(t)=0,0≤t≤1,u(0)=0,u(1)=1,的唯一正解.其中ξi∈(0,1),αi∈(0, ∞)为满足∑m-2i=1αi1(ξi)<1的常数,i∈{1,2,…,m-2}.通过考察f在有界集上的性质,运用Krasnosel'skii锥拉伸与锥压缩型不动点定理及格林函数的性质,获得了其正解的存在性与多解性,推广和改进了已有的相关结果.  相似文献   

6.
利用锥上的不动点定理讨论多点边值问题u" λf(t,u)=0,t∈(0,1),u'(0)=0,u(1)=m-2∑i=1aiu(ξi)正解的存在性,其中:f(t,u)≥-M,而M>0;λ>0,ai≥0,i=1,2,…,m-2,0<ξ1<ξ2<…<ξm-2<1:特别的,不要求f满足超线性或次线性条件.  相似文献   

7.
本文研究了如下三阶微分方程的无穷多点边值问题{u'+λa(t)f(u)=0,t∈(0,1),u(0)=βu′(0),u(1)=∑∞i=α1u(ξi),u′(1)=0正解的存在性,其中参数λ0,ξi∈(0,1),αi∈(0,∞],且满足∑∞αi i=1 1,0∞∑αiξi(2-ξi)1.a(t)∈C([0,1],[0,∞)),f∈C([0,∞),[0,∞)),运用锥拉伸与压缩不动点定理,在f满足超线性和次线性的情况下,本文不仅得到了该边值问题正解的存在性,同时还得到了使得问题有解的特征值λ的取值范围.  相似文献   

8.
本文运用Lerary-Schauder原理讨论了如下二阶常微分无穷多点边值问题u″(t)=f(t,u(t),u′(t)) e(t),t∈(0,1),u′(0)=0,u(1)=sun from i=1 to ∞ aiu(ξi)解的存在性.  相似文献   

9.
考虑如下m点边值问题解的存在性:u″=f(t,u,u′)+e(t)(00,i=1,2,…,m-2;0<ξ1<ξ2<…<ξm-2<1;∑m-2i=1aiξi≠1.通过对一族边值问题解的先验估计,利用Leray-Shauder连续性定理,得到解的存在性.  相似文献   

10.
利用不动点定理,并赋予f,g一定的增长条件,讨论了一类二阶常微分方程组u″(t)+f(t,v(t))=0,0≤t≤1;v″(t)+g(t,u(t))=0,0≤t≤1;u′(0)=∑i=1 m-2 biu′(ξi),u(1)=∑i=1 k aiu(ξi)-∑i=k+1 m-2 aiu(ξi),v′(0)=∑i=1 m-2 diu′(ηi),v(1)=∑i=1 l civ(ηi)-∑i=l+1 m-2 civ(ηi),多个正解的存在性,其中f,g∈C([0,1]×[0,∞),[0,∞)).  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.
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   

13.
王慧 《科技信息》2008,(10):240-240
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   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
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   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
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   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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