由任一非零特解构造复合微分方程边值问题的解

针对二阶线性齐次微分方程边值问题,本文研究了解式的相似结构,获得了相似核函数;说明了该类微分方程边值问题的解,可以首先由定解方程的任一非零特解和某一边界条件的系数构造出相似核函数,再由另一边界条件中的系数决定的相似结构式进行组装,即可得到二阶线性齐次微分方程边值问题的解;这种不必去具体繁琐地进行推导求解的方法就是所谓的相似结构构造法(简称相似构造法),该法是解决微分方程的复杂边值问题和解决有关工程科学问题的一个创新的思想和简单而行之有效的方法.     

非齐次梁方程初边值问题形式级数解的收敛性

考虑线性非齐次梁方程初边值问题的形式级数解的收敛性问题.证明了非齐次梁方程初边值问题的古典解和广义解的存在唯一性.     

一类抛物型方程的Galerkin方法

对一类抛物方程非齐次边值问题,先利用变量替换法,将其非齐次边值问题转化为齐次边值问题,再运用Galerkin方法证明其解的存在性.     

第一、二、三类非齐次线性边界条件的齐次化

本征函数法和格林函数法是求解数学物理定解问题的常用方法，这些方法要求问题具有齐次线性边界条件，若定解问题具有非齐次线性边界条件，则必须选择辅助函数，使之化为齐次边界条件，本文首先对稳定的非齐次边界条件进行讨论，得到选择辅助函数的普遍方法和结果；然后对其结果应用参数变易法进行改造，使之适应于不稳定的非齐次边界条件，从而得到选择辅助函数的普遍方法和结论。     

n阶线性微分方程和线性方程组边值问题的一个求解公式

本文利用n阶非齐次线性微分方程和方程组解的表达式,导出了一个非齐次线性微分方程和方程组边值问题的求解公式.此公式比借助格林函数求解边值问题来得简便,所得结果是文献[1]的推广.     

求解一类二阶线性齐次微分方程边值问题的相似结构法

研究二阶线性齐次微分方程边值问题{y″+p(x)y’+q(x)y=0,[Ey+(1+EF)y’]x=a=D,[Gy+Hy’]x=b=0,其中,D、E、F、G、H、a和b均为已知的实常数,且D≠0,G2+H2≠0,a相似文献   

n阶线性微分方程和线性方程组边值问题的一个求解公式

本文利用n阶非齐次线性微分方程和方程组解的表达式，导出了一个非齐次线性微分方程和方程组边值问题的求解公式。此公式比借助格林函数求解边值问题来得简便，所得结果是文献[1]的推广。     

带位移和斜微商的广义Riemann型边值问题

本文使用奇异积分方程组研究边值问题的方法，讨论了广义解折函数带一个位移和一阶微商的广义Ｒｉｅｍａｎｎ型边值问题，给出了其可解性条件，及其齐次问题与相应的齐次共轭问题的线性无关解个数之间的关系。     

几类线性分数阶微分方程解的结构

用分离变量法分析研究时间-空间分数阶线性微分方程解的结构,得到了精确解,并用待定特殊函数法得到了常系数齐次线性分数阶微分方程的精确解,证明了解的存在性,建立了相应解的结构性定理.     

非齐次边界条件KdV方程的有限差分格式

构造一个新的变量将KdV方程的非齐次边界转化为齐次边界,对于变换后的KdV初边值问题提出一个3层二阶精度线性有限差分格式.分别用离散能量法和von Neumann稳定性分析法证明了该格式解的唯一性和无条件稳定性.数值算例验证了该格式的精度和有效性.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Features of Women's language

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.