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1.
完全右内射幺半群是一类具有重要研究价值的半群,完全α-绝对纯幺半群和完全右FC-内射(FSF-内射)幺半群是其两种不同的推广.通过引入(α,β)-绝对纯S-系的概念,将完全α-绝对纯幺半群和完全右FC-内射(FSF-内射)幺半群进一步推广为完全(α,β)-绝对纯幺半群,即所有S-系是(α,β)-绝对纯的幺半群.讨论了(α,β)-绝对纯S-系的性质,给出了完全(α,β)-绝对纯幺半群的理想-同余刻画, 从而完全α-绝对纯幺半群和完全右FC-内射(FSF-内射)幺半群等的对应结论都可由此结果推出.  相似文献   

2.
右适当幺半群S称为型F的,如果S是F-rpp半群.目的是给出型F的右适当幺半群的F*-幺半群结构定理:半群S是型F的右适当幺半群当且仅当S同构于F*(M,X,Y),这里F*(M,X,Y)是F*幺半群系统.此结果推广了F-逆半群的相关结果.  相似文献   

3.
本文对幺半群S的任意右商滤子P,给出了完全右P-内射幺半群的“理想一同余”形式的刻划,推广了有关内射S-系的结果。  相似文献   

4.
在S、T都是幺半群且T含有右零元,A是左S-系,B是左T-系,W=S×F(A.T)是由A决定的S和T的圈积的假设下,给出了左W-系AwrB是纯整系的充要条件。利用该结果可得到一种构造纯整系的新方法。  相似文献   

5.
设S是幺半群,FGWI,WPF,ST_F分别表示有限生成弱内射右S-系、弱拉回平坦右S-系和强挠自由右S-系的类。证明了在有左零元的左reversible幺半群上,每一个右S-系A_i∈FGWI当且仅当_(i∈I)A_i∈FGWI;在Noetherian幺半群上,任意fg-弱内射S-系的有向上极限是fg-弱内射的;同时考虑了WPF-覆盖和STF-覆盖,给出了每一个右S-系都有FGWI-覆盖的条件。证明了若S是有有限几何型的有限生成幺半群,每一个右S-系都有WPF-覆盖,以及在任意幺半群S上,每一个右S-系都有ST_F-覆盖。  相似文献   

6.
设S是幺半群。 研究了所有正则右S-系是弱内射系的幺半群的特征,纠正了Moon给出的错误结论, 并讨论了正则系是fgdu-弱内射S-系的幺半群的等价刻画。  相似文献   

7.
拟投射系     
设S是幺半群,称A是拟投射S-系,如果对于S-满同态f:A→B和任意S-同态g:A→B,存在S-同态h:A→A使得fh=g.研究了拟投射S-系的性质,得出结论:(1)S是(半)完全幺半群任意右S-系(有限生成)有一个拟投射复盖S-系;(2)S是右遗传幺半群S的任意投射系是拟投射的.  相似文献   

8.
利用幺半群的*-右可消性,构造出*-左ample幺半群的最小*-右可消同余,改进了型A幺半群的最小右可消同余.  相似文献   

9.
介绍弱左正则幺半群的概念,指出在可交换半群中,完全正则、弱左(右)正则和完全幂等是等价的.进一步地,通过模糊理想、模糊左理想和模糊右理想的性质刻画了弱左正则幺半群,给出了一个幺半群是弱左正则的等价条件.  相似文献   

10.
给出了幺半群S-系范畴的若干对自然同构的函子.研究了Hom函子和张量函子的性质,得到了幺半群的一些刻画.在幺半群S-系范畴中得到若干函子的自然同构.另外,对左R右S-双系U,左R-系(右S-系)M,证明了:M是U-无挠的当且仅当U上生成M.  相似文献   

11.
F—纯子模     
设F是环R上的右Gabriel拓扑,文中用线性方程组给出了S-R-模N是S-R-模M的F-纯子模的充分必要条件,并对绝对F-纯模进行了刻划。  相似文献   

12.
引入F-纯正合序列的概念,利用它讨论了F-平坦模及模的F-平坦维数。  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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。  相似文献   

20.
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.  相似文献   

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