模的投射覆盖、内射包络与局部环

利用环模理论和同调代数的方法,研究了模的投射覆盖、内射包络与局部环之间的关系.设Q是一个投射-内射左R-模.证明了如果同态f:Q→X是非投射模_RX的投射覆盖且自同态环End(_RX)为局部环,那么包含同态i:Kerf→Q为Kerf的内射包络;如果同态f:Y→Q是非内射模_RY的内射包络且自同态环End(_RY)为局部环,那么标准投射π:Q→Cokerf为Cokerf的投射覆盖.结果表明,模的投射覆盖、内射包络与局部环之间有着密切的联系.     

弱GPP-环的Ore扩张

设α是一个自同态,δ是环R的α微分.如果R是α刚性环,则R是弱GPP环当且仅当R[x;α,δ]是弱GPP环.设R是α刚性环,R[[x;α]]是PP环当且仅当R是PP环,且R的任意可数幂等元集在I(R)中有广义join.     

环的幂自同态与Frobenius同态

通过对环的幂自同态结构的研究，刻画出无零因子环的所有幂自同态。     

NMP-内射环

环R称为右NMP-内射环,如果对于每个由R的幂零元生成的主右理想到R的单同态都能扩充到R的一个自同态.左NMP-内射环可类似定义.本文我们首先引入并且刻画了NMP-内射环,说明了它是MP-内射环的真推广.然后研究了NMP-内射环的一些性质,推广了MP-内射环和ni-l内射环的一些已有结论.     

拟Abel环

设R是一个环,M是双R-模.若对每个e∈E(R),有eR(1-e)Me=eM(1-e)Re=0,则称M为拟Abel模,这里E(R)表示R的幂等元集合.若R-双模R是拟Abel的,则称R为拟Abel环.证明了如下结果:①R为拟Abel环当且仅当对任意的a∈N(R),e∈E(R),ea=0蕴涵eRae=0,这里N(R)表示R的幂零元集合;②R为Abel环当且仅当R为幂零自反环和拟Abel环;③设σ为环R的环自同态映射且满足条件: e∈E(R),σ(e)=e,则R为拟Abel环当且仅当R(σ)为拟Abel模.     

超环上的f导子

利用超环的自同态将超环上的导子进行了推广,引入并研究超环的f导子。证明了如果(R,d)是一个强f导子超环并且I是(R,d)的一个强f导子超理想,则(R/I,g)是一个强f导子超环。进一步证明了映射d是超环R上的f导子当且仅当映射Фd是一个同态映射,其中Фd是由d诱导的映射。     

直接有限环

证明了如下结果:1)环R是直接有限环当且仅当每个右R-满射f:R→R是单射;2)若R是右C2环,则R是直接有限环当且仅当每个右R-单射f:R→R是满射当且仅当R/J(R)是直接有限环;3)设R是左半A-bel环,则R是直接有限环;4)设R,S是两个环,RVS是(R,S)双模,则C=RV     

关于诣零n-内射环

主要探讨了两种环的扩张的诣零n-内射性.首先证明了R∝R是左诣零n-内射的当且仅当对任意的δ,γ∈Rn,其中δ的每一个分量是幂零的,均有rRn(lRn(δ)∩(Rnδ:γ))=δR+γrR(δ).其次,证明了对任意的α,β∈Rn,并且α的每一个分量是幂零的,假设从αRn+βrRn(α)到R的每一个同态都能扩张到R的一个自同态,那么S=R∝R是右诣零n-内射的.最后,得到了如下的结果:如果n≥2,并且Tn(R)是右诣零n-内射的,那么R没有非零的幂零元.     

具有弱对称自同态的环

推广了弱对称环的概念,研究了具有弱对称自同态α的环,称为弱对称α-环,讨论弱对称α-环与相关环的关系,研究了弱对称α-环的一些扩张性质。证明了:(1)设α是环R的自同态,则R是α-rigid环当且仅当R是弱对称α-环,且由aRα(a)∈nil(R)可推出a=0,对任何a∈R;(2)设R是半交换环,α是R的自同态,则R是弱对称α-环当且仅当R[x]是弱珔α-sy环。     

一类上三角矩阵环的Skew Armendariz性质

设α是环R的一个自同态．若R是α—rigid环，则R上的上三角矩阵环的子环Wn既是α^-skew Armendariz环又是Armendariz环．     

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.     

A computer generator for randomly layered structures

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

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。     

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.