一类具有Holling-Ⅱ型响应函数的捕食模型定性分析

讨论具有Holling-Ⅱ型响应函数的捕食模型的齐次Neumann问题.首先通过构造上下解的方法研究了该问题半平凡解的全局稳定性,利用Lyapunov泛函和Routh-Hurwitz判定法分别讨论了正常数平衡解的全局稳定性和局部稳定性.其次给出了正平衡解的正的上下界的估计,以及非常数正平衡解的不存在性,最后利用拓扑度的方法研究了非常数正平衡解的存在性.     

一类带交错扩散项的捕食-被捕食模型平衡解的存在性和稳定性（英文）

主要研究了一类带交错扩散项的捕食-被捕食模型平衡解的存在性和稳定性.应用全局分岔理论得到正平衡解的存在性.应用谱分析和稳定性理论得到分岔点附近的分岔解的局部稳定性.     

一类具Size结构的非线性种群平衡解的稳定性

考虑一类具有Size结构的非线性种群系统平衡解的稳定性条件.利用不动点定理得到了平衡态的存在唯一性,给出平衡态的表达式,导出了系统的特征方程,从而获得平衡解的稳定性条件.     

具有Holling Ⅲ型功能反应捕食模型的稳定性及最优收获策略

研究了一个具有Holling Ⅲ型功能反应,且有环境控制量和税收的捕食-食饵系统.首先讨论该常微分系统的正平衡解的存在性.然后,通过线性近似的方法,得到正平衡解的局部渐近稳定性的条件;通过建立李雅普诺夫函数,得到正平衡解的全局渐近稳定性的条件.最后,将问题转化为最优控制问题,通过建立Hamilton函数,根据Pontryagin最大值原理求出一个最优经济平衡解.     

一类竞争型捕食者-食饵交错扩散模型的Turing不稳定性

研究一个带有食饵保护的竞争型捕食者-食饵交错扩散模型.首先讨论弱耦合反应扩散系统正常数平衡解的局部和全局渐近稳定性;其次分析交错扩散系数对正常数平衡解稳定性的影响,证明当交错扩散系数充分大时会产生Turing不稳定现象.     

一类用常微分方程描述的带接种的SEIR传染病模型稳定性研究

对于SEIR传染病模型的研究,文章依据动力学原理建立了由常微分方程组描述的数学模型;利用泛函分析和雅克比矩阵证明了模型方程平衡解的存在性和稳定性.应用Routh-Hurwits判别法讨论分析了平衡解的局部稳定性。     

具有Michaelis-Menten收获和避难所的捕食系统的分歧

在齐次Neumann条件下研究了一类具有扩散的带Michaelis-Menten收获项和避难所的捕食-食饵模型.首先利用稳定性理论证明了正常数平衡解的局部稳定性;其次利用最大值原理、Harnack不等式和能量积分的方法给出了正常数平衡解的先验估计和非常数正解的不存在性;再次由单特征值分歧理论得到了系统发自正常数平衡解处的解分支;最后利用Hopf分歧理论研究了在正常数平衡解处Hopf分歧存在的条件.     

传染病动力学常微分方程模型解的大时间性质

研究了传染病常微模型三次系统解的非负性、整体解的存在唯一性,并利用Liapunov函数法和霍维茨准则等研究了非负平衡解的稳定性及渐近稳定性.     

二维非线性Schrdinger方程平衡解的稳定性分析

讨论了非线性Schro。dinger方程:iut=-Δu-λu2u-(1+iα)u,α≠0,λ∈R.平衡解的稳定性,并应用行波解的方法证明了:当α>0时相应的平衡解是不稳定的;当α<0时,相应的平衡解是渐近稳定的.     

一般的Activator-Inhibitor模型的分支解的稳定性

本文利用线性稳定性及分支解稳定性的一般定理讨论了 Activator-Inhibitor模型所对应的平衡态方程组的分支解的稳定性,得出了其分支解在一定条件下是稳定的,从而在理论上保证了 Activator-Inhibitor 模型的稳定的非常数平衡解的存在性.     

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.     

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.     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-