等腰梯形的单叶性内径

利用David Calvis方法研究等腰梯形的单叶性内径,证明了边序列为aaab最小角为kπ(其中b=a 2acoskπ,0≤k≤1/3)的等腰梯形P的单叶性内径为2k2.     

基于三正交消影点的摄像机标定方法及实验

利用2个非平行的长方体作为标定模版,采用Hough变换检测出图像中长方体的棱,然后计算出2组三正交方向上的消影点,再根据消影点与摄像机内参数的约束方程求出摄像机内参数.该方法原理简单,只需要一幅图像就可实现摄像机内参数的求解.实验结果表明,该方法有较高的精度和稳定性.     

基于正交消影点的摄像机标定方法

利用3个正交方向的消影点在图像平面上提供的几何关系,首先计算出主点坐标,然后根据正交方向上的消影点与消影线对绝对二次曲线的像的约束方程,计算出其余参数;方法原理简单,只需要一幅图像就可实现摄像机内参数的求解;结果表明,方法具有较高的精度和较好的稳定性。     

表面方向的计算

本文描述了一种表面方向的计算方法,该方法是建立在成像设备一阶近似模型及射影几何的基础上的。用该方法,可由两个消影点,一个消影点,甚至无消影点(在一定条件下)求得表面方向。文中还推导出一组十分有用的公式并给出了计算机模拟的结果。     

k连通图在边点割原子与点割上的可去边

图的可收缩边与可去边是研究连通图的构造和使用归纳法证明连通图的一些性质的有力工具.利用边点割断片的性质给出某些k连通图中在特定子图上可去边的分布情况,得到了最小度至少为(3(k-1)/2)或围长至少为4的k连通图(k≥4)中由边点割原子与点割所导出的子图的每一条边都是可去边.     

由圈得到的一类优美图

刘瑞元在〔1〕中证明一个 n(n≥6)个顶点的圈增加两条弦所得图优美,本文证明圈增加若干弦所得图优美.定理具有4k+r 个顶点的圈 C(r=0,1,2,3),可增加 t(1≤t≤2k)条弦,使所得图 C′优美.定理的证明分4种情况:r=0,l,2,3.引理1 具有4k 个顶点的圈 C,可加上t(0≤t≤2k)条弦,使所得图 C′优美。引理2 具有4k+1个顶点的圈 C,可增加t(1≤t≤2k)条弦,使所得图 C′优美.引理3 具有4k+2个顶点的圈 C,可增加t(1≤t≤2k)条弦,使所得图 C′优美.引理4 具有4k+3个顶点的圈 C,可增加t(1≤t≤2k+1)条弦,使所得图 C′优美.     

mC3∨nC3和mC4∨nC4点可区别Ⅰ-全染色及Ⅵ-全染色

设f为简单图G的一个一般全染色(即若干种颜色对图G的全部顶点及边的一个分配),如果任意两个相邻点染以不同颜色且任意两条相邻边染以不同的颜色,则称为图G的Ⅰ-全染色;如果任意两条相邻边染以不同的颜色,则称为图G的Ⅵ-全染色.用C(x)表示在f下点x的颜色以及与x关联的边的色所构成的集合(非多重集).对图G的一个Ⅰ-全染色(分别地,Ⅵ-全染色)f,一旦?u,v∈V(G),u≠v,就有C(u)≠C(v),则f称为图G的点可区别Ⅰ-全染色(或点可区别Ⅵ-全染色),简称为VDIT染色(分别地,VDVIT染色).令χ~Ⅰ_(vt)(G)=min{k|G存在k-VDIT染色},称χ~Ⅰ_(vt)(G)为图G的点可区别Ⅰ-全色数.令χ~Ⅵ_(vt)(G)=min{k|G存在k-VDVIT染色},称χ~Ⅵ_(vt)(G)为图G的点可区别Ⅵ-全色数.利用构造具体染色的方法,讨论了联图mC_3∨nC_3和mC_4∨nC_4的点可区别Ⅰ-全染色和点可区别Ⅵ-全染色,并给出了联图mC_3∨nC_3和mC_4∨nC_4的点可区别Ⅰ-全色数和点可区别Ⅵ-全色数.     

二分图中存在包含经过给定边的大圈的2-因子的度条件

该文主要证明了若G=(V1,V2;E)是一个满足|V1|=|V2|=n≥sk的二分图,其中k,s,n为3个正整数且k≥2,s≥4,如果σ1,1(G)≥2「(1-1/s)n k﹁,那么对G的任意k条独立边e1,…,ek,G有一个包含k个点不交的圈C1,…,Ck的2-因子,使得ei∈E(Ci),且|Ci|≥2s.     

基于影灭点的单视图三维重构

提出了一种单视图三维重构方法,该方法需要用户提供图像点及其对应三维点之间的几何信息.由于结构场景有大量平面构成,存在大量的平行性和正交性约束,所以该方法主要应用于结构场景的三维重构.重构过程分为两部分:首先,基于三组互相垂直方向的影灭点,对方形象素摄像机进行定标;然后,基于用户提供的共面性和场景平面的影灭线,计算点的三维坐标.采用真实图像测试,说明该方法有效且简单易用.     

非连通图C4k 2(2)∪Gm 的优美性

证明了:当k≥1时,非连通图C(2)4k+2∪Gm是优美图,其中Gm是任意一个有m条边的优美图.     

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。     

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.