奇摄动常微分方程系统的数值解法

讨论奇摄动常微分方程系统的二点边界值问题，这是奇摄动问题中较难的部分．中介绍了多过渡点的选取方法．依此法构造不等距差分格式，在最大范数下证明新的差分格式关于摄动参数是一阶一致收敛．多过渡点确定了网格划分从细网格到中等同格和粗网格的过渡，而Shishkin Sehenle(单过渡点法)只将网格分为细网格和粗网格．多过渡点法很好地拟合了边界层的性质，在实际应用中相当有效，其收敛阶也高于Shishkin网格法．     

带有小参数的抛物型方程的多过渡点差分格式

讨论两类时间上带有小参数的抛物型方程,介绍了多过渡点的选取方法,依此法构造不等距差分格式并证明新的差分格式关于摄动参数是一阶一致收敛.多过渡点差分格式的收敛阶与Bakhvalov法相同,高于Shishkin网格法,但计算量比Bakhvalov法小得多,在实际应用中相当有效.     

奇摄动问题的多过渡点数值解法

讨论奇摄动混合边值问题,介绍了多过渡点的选择策略,依照多过渡点的选择而构造了不等距网格差分格式,并证明新的差分格式为一阶一致收敛,提高了Shishkin网格法(单过渡点法)的收敛阶．     

非线性分数阶常微分方程的一种新的高阶数值方法

首先利用分段三次插值公式构造了非线性Caputo分数阶常微分方程的高阶一致收敛的数值格式，其次给出了高阶一致收敛的数值格式的理论结果，最后利用数值实验验证了该数值格式的截断误差是4-θ阶。     

修正后的Lagrange插值多项式的逼近阶

对Ｌａｇｒａｎｇｅ 插值多项式进行了修正,构造了一个算子,它对于在区间［ － １ ,１］ 上有任意阶连续导数的函数都一致收敛,并且收敛阶达到了最佳,而且算子的最高收敛阶为１／ ｎｒ ．     

修正的S.N.Bernstein型三角插值多项式的逼近

构造了一个三角多项式算子Hn(f；r，x)(r为自然数)，使其对每一个以2π为周期的连续函数都能在全实轴上一致收敛，并给出了最佳收敛阶的估计．     

椭圆型方程双向转向点奇摄动问题的一致差分格式

讨论具有双向转向点的椭圆型方程奇摄动问题的一致数值解法，证明带指数型拟合因子的差分格式关于小参数ε的一致收敛结果．给出数值例子，计算结果表明了理论结果的正确性     

一类非线性奇摄动边值问题的迭层解

本文研究了一类非线性方程奇摄动问题。在适当的条件下，先利用幂级数形式展开方法构造了原问题的外部解；其次，利用伸长变量在左端点附近构造问题解的第一边界层校正项，并利用更强的伸长变量，仍然在左端点附近构造问题解的第二边界层校正项，第二边界层的厚度比第一边界层的厚度更小，形成在左端点附近的边界层的迭层；最后利用微分不等式理论证明了边值问题解的存在性和在整个区间内一致有效性和渐近性态。     

一类线性插值算子的导数逼近

为了改善Lagrange插播算子的一致收敛性并提高算子最佳收敛阶,我们以一类Ja cobi多项式的零点作为插值结点,通过对插值结点处函数值的线性组合,构造了一类线性插值算子,给出了该类算子的最佳收敛阶定理;进而研究了此类算子的导数逼近问题,利用对算子进行分项估计的方法,不仅证明了该算子的导数一致收敛于具有连续导数的函数,而且给出了算子的一阶导数逼近函数导数的最佳收敛阶.     

推广的二元三角插值算子的收敛与饱和

构造了不依赖于结点组的更广的一类二元Fourier插值算子和二元离散的Fourier插值算子,估计了两类算子的收敛阶,并且证明了对于二元连续周期函数类来讲,该收敛阶是最优的.更进一步讨论了这两类算子的饱和问题,得到了饱和阶的估计.在收敛阶和饱和阶的度量上,论文结果与以往文献中的结果是一致的.     

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.