二次型ECSTR模型存在一个正的不变区域

研究了一个以周期函数为系数的非线性常微分方程系统——一个推广的二次型Gray—Scott模型的CSTR模型．证明该模型存在一个严格的正的不变区域，给出模型的线性化在不变区域内的一些性质．     

非参数AR（1）误差下AR模型定阶

对一类非正态误差的模型AR，在待定阶数p的情况下，给出误差项中未知实函数依概率有界的定理，可把非正态误差转化为正态情强，最后运用正态误差下AR模型的方法确定阶教和参数，井给出一个算例。     

带收获和自食的两种群竞争系统的全局渐近稳定性

文献[1]提出了一个带收获和自食的两种群竞争系统,讨论了该模型解的存在条件和正性，得到了一个正平衡点局部渐近稳定的充分条件,本文讨论了该平衡点的全局渐近稳定性和对成年种群的最优收获量.     

SB模型恒稳定解的degree

研究一个非线性常微分方程系统——一个简化的Brusselator模型．证明这个模型存在一个严格的正的不变区域，在此区域内该模型存在唯一的恒稳定解，且解的degree为1．     

隶属云模型的统计性质和有限精度实现

隶属云模型是定性和定量描述之间的转换工具，其数字特征可用期望值E，熵σ，超熵h3个数值来表征。分析了云模型中隶属度y作为一个随机变量的统计分布特征，导出了它仅与h／σ相关联，与E无关的概率密度解析公式；为将正态隶属云模型用于产生跳频码序列，讨论了如何处理因数字电路的有限精度和芯片资源有限，在正态随机数的实现方法及平方指数函数计算中遇到的一些问题。     

一类三种群食物链扩散模型的稳定性

分析了一类由一个食饵种群、一个低级捕食者种群和一个高级捕食者种群组成的三种群食物链扩散模型.利用极值原理和Young不等式得出了解在齐次Neumann边界条件下存在唯一性和一致有界性,并用线性化方法和Lyapunov函数方法讨论了该模型正平衡点的稳定性,分别得到了该模型正平衡点的局部和全局渐近稳定性定理.     

无限大双层越流油气藏井底压力的精确解

采用最大有效井径的概念，在考虑表皮效应和井筒储存影响的条件下，导出了一个具有层间越流的无限大双层越流油气藏井底压力的动态模型，通过拉氏变换，得到了拉氏空间下以Bessel函数表示的精确解。运用Crump数值反演方法，得到了实空间的解，分析了压力动态特征，计算结果表明：该模型不但适合于表皮系数为正的情况，也适合于表皮系数的为负的情形，而Burdet模型只适合于表皮系数为正的情况。由于解释模型参数集团化，更有利于绘制典型曲线，能够获得更加准确的地层参数。     

二次型CSTR模型和SG模型的恒稳定解的degree

研究了两个非线性常微分方程系统二次型CSTR模型和SG模型.证明了这两个模型分别存在一个严格的正不变区域且它们在各自的正不变区域内只有一个恒稳定解,这个恒稳定解的Degree是1.这为研究推广的二次型CSTR模型和SG模型解的存在性奠定了基础.     

一个造血模型周期解的存在性及唯一性

研究一个造血模型的正周期解的存在性及唯一性等问题，并得到了这个方程存在唯一正的周期解的新结果。     

时间模上非线性两-点边值问题的正解

变系数模型是由古典的线性模型发展而来，它们可以很好地检验函数系数随着协变量的变化程度．文章用PLR提出了变系数模型误差方差的估计，并研究了它的渐近正态性，进一步用一个模拟例子来说明估计的结果是有效的．     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the