某类一阶中立型微分方程的振动性

讨论具有多滞量的一阶中立型微分方程dx/dt[x（t）-^k∑i=t Pi（t）x（t-τi）]＋^i∑j=1Qj（t）x（t-σj）=0其中τi，σi∈（0，∞），Pi∈C（[t0，∞]，R），Qj∈C（[t0，∞]，R^＋），i=1，2，…，k;j=1，2，…，l。给出了上速方程所有的解振动的充分条件，并且推广了单滞量情形的结果。     

二阶泛函微分方程的渐近性和振动性

研究了二阶非线性中立型时滞泛函微分方程[A(t)x(t)-∑li=1Pi(t)x(t-τ)]＂+∑mj=1Qj(t)fj(x(t-σj))=0的振动性, 分别得到了方程所有解振动和方程存在非振动解的充分条件, 推广和改进了现有文献中的相关结果.     

具连续变量的二阶时滞差分方程的振动性

研究一类具有连续变量的二阶时滞差分方程△2τx(t)=p(t)x(t-σ)t≥t0＞0和△2τx(t)=m∑i=1Pi(t)x(t-σi),t≥t0＞0的解的振动性,给出了其有界解振动的几个充分条件.     

一类中立型差分方程非振动解的存在和渐近性

讨论了非线性多时滞中立型差分方程　　　　Δ(x(n) - p(n)x(n-τ) ) +q(n) ∏mi =1(x(n -σi) ) αisgnx(n-σi) =0的非振动性 .其中 :p(n) ≥ 0 ,q(n)≥ 0且不恒等于 0 ;τ ,σi 是非负整数 ,i=1,2 ,… ,m ;αi >0 ,∑mi =1αi =1;Δ是前差分算子 ,Δx(n) =x(n+1) -x(n) .利用序列及映射的构造得出了方程最终正解的存在条件 ,并且引用以指数形式趋于 0的定义讨论了非振动解的渐近性态 .     

一类非线性多时滞中立型差分方程的振动性

讨论了非线性多时滞中立型差分方程　　　　Δ(x(n) - p(n)x(n-τ) ) +q(n) ∏mi =1(x(n -σi) ) αisgnx(n-σi) =0的振动性 .其中 :p(n) ≥ 0 ,q(n)≥ 0且不恒等于 0 ;τ ,σi是非负整数 ,i=1,2 ,… ,m ;αi >0 ,∑mi=1αi=1;Δ是前差分算子 ,Δx(n) =x(n+1) -x(n) .采用离散的Riccati变换和某些函数变换 ,利用反证法 ,得出了此方程所有解的若干振动准则 .     

一类非线性中立型时滞差分方程的振动性

讨论了一类高阶中立型多时滞差分方程△＇（x（n）-p（n）x（n-k）＋q（n）^mП（j=1）｜x（n-σi）｜a^Sgnx（n-σ1）=0，n=0,1,…的振动性，获得了方程在[^m∑（j=1）]αi=1条件下振动的一个充分条件，同时又给出该方程非振动解趋于零的判据。     

高阶中立型泛函微分方程解的渐近性与振动性

本文讨论了一类高阶中立型微分方程d^n/dt^n[X(t)k/∑／=1Pi(t）X(t-τi)] m/∑/j=1Qj(t)X(t-σj)=0,t≥t0(1)研究了方程（1）的非振动解的渐近性，并给出了方程（1）的所有解振动的一些充分判据，所得结果改进和推广了文[1-3]中相应的结论。     

一类高阶非线性中立型差分方程的振动性

研究了一类高阶非线性中立型时滞差分方程Δd(a(n)x(n)-p(n)x(n-τ))+sΣj=1qj(n)fj(x(n-σj))=0的振动性,得到了该方程振动的若干充分条件,推广了现有文献中的结果.     

一类中立型差分方程正解的存在性

利用在集合上定义映射和Knaster不动点原理,讨论了奇数阶多滞量中立型差分方程△m[x(n)-x(n-τ)] L∑i=1qi(n)x(n-σi)=0有界正解的存在性,得出了相应方程有界正解存在的充要条件.     

二阶非线性中立型微分方程正解存在性

文章得到了二阶非线性中立型微分方程[a(t)x(t)-∑mi=1bi(t)x(t-τi)]″-∑lj=1Pj(t)fj(t,x(t-σj))=0,t>t0,和相对应的不等式[a(t)x(t)-∑mi=1bi(t)x(t-τi)]″-∑lj=1Pj(t)fj(t,x(t-σj))≥0,t>t0,存在最终有界正解是等价的,其中τi>0,σj≥0,a(t),bi(t),Pj(t)∈C([t0,∞],R ),(i=1,2,…,m,j=1,2,…,l),当t充分大时,Pj(t)不恒等于零,fj(t,u)是关于u的单调不减的实函数,且当u>0时,fj(t,u)>0,(j=1,2,…,l).     

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。     

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.