论弹性力学广义变分原理的临界变分现象

应用拉氏乘子法消除Ｈｅｌｌｉｎｇｅｒ－Ｒｅｉｓｓｎｅｒ变分原理的约束关系时,在识别拉氏乘子的过程中,会出现拉氏乘子为零的现象,这种现象称为临界变分现象,本文提出了一些新的观点来解释这种现象。     

流体力学中的临界变分现象及其消除方法

通过一个具体例子,阐述了流体力学中存在的各种临界主分现象,并指出临界变分是拉氏乘子的固有特性。详细综述了消除临界变分的各种方法：刘高联预处理拉氏乘子法、钱伟长高阶拉氏乘子法及作者提出的半反推法。     

无小参数非线性振动方程的近似方法

本文提出了一种求解非线性方程的迭代算法 ,它不依赖于小参数 ,是先给方程一个带待定函数的试函数作为初始近似解 ,然后用拉氏乘子法构造一个迭代公式 (校正泛函 ) .试函数中的待定函数可用变分直接方法确定 ,而校正泛函中的拉氏乘子可用变分理论最佳确定 .应用这种方法不会出现长期项 ,其结果表明这种新方法是比较有效的 .     

求解摄动问题的一种新方法

本文提出了求解摄动问题的一种新方法－变分迭代算法,这种方法不按小参数展开,而是先给出一个近似解,然扣用拉氏乘子法校正其近似解,而拉氏乘子可用分变分理论最佳识别。     

基于Chandrasekharaiah广义线性理论的热压电力学的耦合广义变分原理

系统推导了热压电力学的变分原理。若应用传统的拉氏乘子法,由于会出现临界变分现象,不能得到本文的结果。本文指出临界变分是拉氏乘子的固有特性,半反推法是克服临界变分的有效途径之一。应用半反推法,根据Ｃｈａｎｄｒａｓｅｋｈａｒａｉａｈ关于压电材料的广义线性弹性理论,直接从控制方程及边初值条件,得到了经典意义上的一个耦合广义变分原理。本文的理论将给有限元方法、无单元方法及一些变分直接方法（如Ｒｉｔｚ法,Ｔ     

关于拉氏乘子法的细节及其作为变分原理的约束判据的可能性

本文就待定的拉氏乘子法和已识别的拉氏乘子法的区别进行了讨论,对现存的两种经验的拉氏乘子的识别方法进行了归纳,提出了识别的唯一性问题和识别的唯一性前提,最后对拉氏乘子法作为弹性力学变分原理是否存在约束条件的判据的可能性进行了讨论。     

双混合乘子法和动力学双混合广义变分原理

双混合拉氏乘子法是动力学问题所特有的。动力学问题所特有的两种约束条件——初始条件和终了条件,都可以用该文提出的双混合拉氏乘子法来放松。该文用双混合拉氏乘子法,建立了大变形非线性弹性理论的动力学双混合广义变分原理,这将给位移允许函数的设计和有限元计算带来方便。     

论弹性力学广义变分原理的临界变分状态

本文集中研究弹性力学变分原理中的临界变分状态,指出它的三种表现,并提出一个带预处理的修正拉氏乘子法来排除之。文中用它成功地导出了胡海昌－鹫津广义变分原理（简记作“Ｈ－Ｗ原理”）和由Ｈｅｌｌｉｎｇｅｒ－Ｒｅｉｓｓｎｅｒ亚广义变分原理（简记作“Ｈ－Ｒ”原理）广而得到的另二条广义变分原理,于是,拉氏乘子法的潜力得以更充分发挥,适用范围得以拓广。     

带有Lagrange乘子的变分及其离散差分

对于完整约束的力学系统,不直接消去不独立坐标,而是在作用量中引人Lagrange乘子,本文介绍了带Lagrange有乘子的拉氏和哈氏形式的变分原理,以及介绍带有Lagrange乘子的差分系统的离散变分方法和其差分离散变分方法,并且把所得结果与传统形式(即消去不独立坐标)的结果进行比较.     

建立广义变分原理的一种统一方法

在计算力学的发展中,各种广义变分原理的建立是计算力学发展的一个基础。作者在一篇还未发表的论文中,在钱伟长教授近期提出来的高阶拉氏乘子法的基础上,发展和推广了一种消除多个约束条件的高阶拉氏乘子法。本文进一步应用作者提出的这个方法,并作某些补充以便为建立各种一般形式的广义变分原理提供一个更加一般化的统一方法。为了说明本文方法,本文从最小位能原理出发得到了一个新的三变量无约束广义变分原理,从而证明本文所建议的方法有效性。     

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.