基于比率的3种群扩散捕食-食饵系统的非常数正解

讨论了基于比率的3种群扩散捕食-食饵系统非常数正解的存在性。首先分析了正常数解的渐近稳定性并利用Harnack不等式和极大值原理给出了正解的估计;其次,利用能量方法讨论了非常数正解的不存在性,得到了非常数正解不存在的充分条件;最后,以种群v的扩散率d2作为分歧参数,利用度理论,得到了非常数正解存在的充分条件为:假设a>d,c>m,r+d/a+m/c>2和r+(d/a)2+m/c<2成立,且存在某个n≥1使得μ～∈(μn,μn+1),σn=∑ni=1dimE(μi)是奇数,则存在一个正常数ρ,当d2≥ρ时,捕食-食饵系统至少存在一个非常数正解。     

一类带交叉扩散项的捕食模型正解的存在性

研究了一类具有扩散和交叉扩散的Holling-Tanner捕食-食饵生态模型的正解.交叉扩散项的生物意义是食饵者通过自身保护的方式抵制来自捕食者的侵害.利用最大值原理和Harnack不等式给出了此模型正解的先验估计.进一步利用积分性质讨论了非常数正解的不存在性,相应地证明了当扩散系数d1、d2大于特定正常数,且交叉扩散系数d3有界时,此模型没有非常数正解.利用度理论讨论了非常数正解的存在性,从而得出若此模型的线性化算子正特征值的代数重数是奇数,且交叉扩散系数d3不小于给定正常数时,此模型至少存在一个非常数正解.     

一类捕食-食饵模型共存解的存在性与稳定性

研究了一类具有HollingⅢ型捕食-食饵模型平衡态正解的存在性与稳定性.利用锥上的不动点理论给出正解存在的充分条件;讨论了m充分大时,借助上下解方法构造出模型的正解,并根据线性稳定性理论讨论了该正解的稳定性.结果表明:当参数aλ1,cλ1(-dθ2a/(1+mθ2a))时,共存解存在,且当cλ1时,共存解是线性稳定的.     

一类捕食-食饵模型解的存在性

研究了一类具有避难所的两物种间的捕食-食饵模型在齐次Direchlet边界条件下的平衡态正解的存在性,其功能反应函数为Holling Ⅱ型.利用不动点指标理论得到系统正解存在的充分条件α/d1>λ1,-r/d2>λ1((-cβmθ)/(d2(1+amθ))).     

一类带有交叉扩散项的捕食-食饵模型的共存态

讨论了带有交叉扩散项的捕食-食饵模型在齐次Neumann边界条件下非常数正解的存在性.利用Harnack不等式给出了正解的先验估计,利用Leray-Schauder度理论得出非常数正解的存在性,从而证明了捕食与食饵在一定条件下可以共存.     

一类反应扩散系统非常数正解的存在性

讨论了一类食饵具有避难所的捕食-食饵模型,其边界条件为齐次Neumann边界条件.首先分析了正常数平衡解的渐近稳定性,给出了正解的估计;其次,讨论了非常数正解的不存在性;最后,利用拓扑度理论,给出非常数正解存在的充分条件.     

带有交叉扩散项的Gause型捕食-食饵模型的共存态

研究了带有交叉扩散项的Gause型捕食-食饵模在齐次Neumann边界条件下的非常数正解的存在性.首先利用最大值原理和Harnack不等式对正解的上下界做了先验估计；其次利用积分性质讨论了非常数正解的不存在性；最后在先验估计的基础上运用Leray-Schauder度理论证明了非常数正解的存在性.     

一类带有C-M反应函数的捕食-食饵模型正解的存在性和唯一性

研究了一类带有C-M反应函数的具有一个食饵和两个捕食者的捕食-食饵模型正解的存在性和唯一性.利用不动点指数理论讨论了正解的存在性,给出正解存在的充分条件:rλ1,-m1λ1(e1w-(p1u)/(1+b1u)),-m2λ1(e2v-(p2u)/(1+b2u)).运用稳定性理论和度理论研究了正解的稳定性和唯一性.     

一类异构捕食-食饵退化模型正解的存在性

研究了一类空间非齐次环境下的捕食-食饵扩散模型。在食饵弱增长情形下,利用分歧理论给出了两个半平凡解附近正解的存在性,并刻画了整体结构;在食饵强增长情形下,通过度理论和正则摄动理论给出了正解存在的充分条件:λ∈(0,min{λ1D(Ω0),1/m3}),μ∈(λm1/1-λm3,M]。鉴于空间环境的非齐次性和退化因素的存在,通过数值算例验证了相应理论结果。     

带交叉扩散项的捕食模型非常数正解的存在性

 讨论了一类具有交叉扩散项的捕食食饵模型正解的存在性。利用最大值原理和Harnack不等式给出了模型正解的先验估计,运用积分性质证明了非常数正解的不存在性,再利用度理论得到了非常数正解存在的充分条件。     

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.     

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.     

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.     

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.     

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.