方钢管约束轻骨料混凝土轴压短柱的力学性能

为研究在轴心受压状态下,方钢管约束轻骨料混凝土轴压短柱的破坏模式和力学性能,通过4组8个方钢管约束轻骨料混凝土轴压短柱试件进行了试验研究。试验结果表明:方钢管能够有效改善轻骨料混凝土的脆性特征,使其具有较好的延性;宽厚比(B/t)与配置纵向钢筋对提高试件极限承载力较混凝土强度的影响大;而混凝土强度的提高对改善试件极限承载力作用较小。基于验证的有限元模型,分析宽厚比(B/t)、混凝土强度对混凝土强度提高系数(Kc)的影响规律,得出B/t对Kc的影响较混凝土强度对Kc的影响大,且与试验结果相吻合。     

方钢管约束粉煤灰混凝土轴压短柱受力性能研究

为研究方钢管约束轻骨料混凝土轴压短柱的受力性能,以钢管宽厚比、混凝土强度、配筋率为主要参数,设计了12根方钢管约束粉煤灰陶粒轻骨料混凝土短柱,对其进行了静力加载试验,主要分析了该种构件的受力性能、破坏形态,以及相关参数对其受力性能的影响规律.试验结果表明,在载荷作用下,方钢管对轻骨料混凝土的约束作用明显,有效地提高了轻骨料混凝土的抗压强度,改善了其变形性能.构件达到极限载荷后,仍有较好的承载能力和变形能力,破坏属于潜力耗尽的材料破坏.钢管宽厚比是影响柱受力性能的主要参数.随着钢管宽厚比的增加,构件的受力性能有逐步减退的趋势.混凝土强度和配筋率影响较小.     

方钢管再生混凝土短柱的轴压力学性能试验

为研究钢管宽厚比及再生骨料取代率对方钢管再生混凝土短柱力学性能的影响,设计9根方钢管再生混凝土短柱进行了轴压试验,观察了试件在轴压力作用下的破坏过程,分析了钢管宽厚比和再生骨料取代率对试件荷载—位移和荷载—应变曲线的影响。结果表明,宽厚比及再生骨料取代率对钢管再生混凝土短柱的最终破坏形态影响不大,与普通钢管混凝土短柱相似,各试件均呈剪切破坏,最终破坏时,其纵向变形均超过30 mm;随着再生骨料取代率增大,荷载—位移曲线下降段越陡,但随着钢管宽厚比的增大,再生骨料取代率超过30%后,试件极限承载力越接近,说明考虑再生骨料取代率的不利影响更合理。最后结合试验提出了钢管再生混凝土短柱承载力计算方法,将计算结果与相关规程进行了对比,供工程应用参考。     

钢管再生混凝土短柱轴压力学性能试验

对5个钢管再生混凝土轴压短柱和1个普通钢管混凝土轴压短柱进行试验研究,比较钢管再生混凝土与普通钢管混凝土的破坏模式、荷载-变形关系和承载力关系,分析再生骨料取代率、矿物掺合料和钢纤维对钢管再生混凝土性能的影响.结果表明,钢管再生混凝土轴压短柱与普通钢管混凝土轴压短柱的破坏模式和受力过程基本相同;随着再生骨料取代率的增大,核心混凝土强度降低,变形增大,需要更大的约束效应约束核心混凝土,可以掺入硅粉、粉煤灰等矿物掺合料以及钢纤维来提高钢管再生混凝土轴压短柱的性能.根据现有相关规程对钢管再生混凝土的极限承载力进行计算,得到各规程在计算钢管再生混凝土极限承载力时的适用性.     

轴压下CFRP—钢管约束混凝土柱试验研究

为研究CFRP—钢管约束混凝土柱试件在B式(仅在核心混凝土施加轴压)加载下的轴压力学性能,采用轴压试验的方法对18根CFRP—钢管约束混凝土试件进行核心混凝土轴向加载,分析混凝土强度、CFRP包裹层数和CFRP约束效应系数对试件轴向承载力和轴向位移的影响。试验结果表明,CFRP约束效应系数对试件轴压承载力提高系数贡献最大,CFRP约束效应能防止钢管的屈曲同时限制混凝土裂缝的发展,增大核心混凝土强度和增加CFRP层数,试件轴向承载力有显著提高。同时制作了6根试件进行A式B式加载对比试验,试验结果表明B式加载方式的极限承载力均大于A式加载,B式加载试件在整个加载过程中CFRP都对混凝土产生约束作用,试件的轴压性能相较于A式更加优良。     

高强冷弯钢管混凝土轴压短柱力学性能非线性有限元分析

采用ABAQUS有限元软件对高强冷弯钢管混凝土轴压短柱的荷载变形曲线进行有限元分析,探讨钢材强度、宽厚比、长宽比参数对高强冷弯钢管混凝土轴压短柱承载力的影响.基于实验分析过程,对27根试件有限元模拟的结果采用非线性回归的方法,得出了随着宽厚比和长宽比的提高,钢管混凝土短柱的承载能力相应提高,随着钢管混凝土强度的提高而导致其对核心混凝土的约束能力增高,从而使整体承载能力提高.同时推导出高强冷弯钢管混凝土轴压短柱承载力的实用计算公式,以供实际工程参考.     

空间钢构架—钢管混凝土短柱轴压承载力计算方法

为了研究新型空间钢构架—钢管混凝土短柱的轴压极限承载力的计算方法,分析了空间钢构架—钢管混凝土轴压短柱的约束作用机理,在已有试验研究和有限元非线性分析的基础上,采用叠加法并考虑空间钢构架对钢管外混凝土的约束作用和钢管对核心混凝土的约束作用,建立了空间钢构架—钢管混凝土轴压短柱的极限承载力计算公式,其计算值与试验值符合较好,可以较好地计算空间钢构架—钢管混凝土短柱的轴压极限承载力。     

方钢管-钢骨高强度混凝土组合短柱轴心受压承载力研究

基于极限平衡理论和方钢管-钢骨高强度混凝土组合短柱的工作原理,引入方钢管等效约束折减系数和核心混凝土强度折减系数,将方钢管对混凝土的约束以及混凝土强度等效替换成相应的圆钢管对混凝土的约束以及混凝土强度,对方钢管、核心混凝土与内置钢骨在三向受力的约束效应下的轴压极限承载力进行了分析研究。利用组合短柱的力学平衡方程及屈服条件,推导出了该新型组合短柱在轴心压力作用下的极限承载力理论计算公式,并将该理论公式的计算结果与试验结果进行对比。研究结果表明：理论计算的极限承载力与试验吻合好,该理论计算公式具有较强的适应性,对此类组合短柱在工程实际中的设计计算具有参考价值。     

方钢管橡胶混凝土短柱的轴压力学性能试验

为了研究钢管橡胶混凝土柱的轴压力学性能,对8个方钢管橡胶混凝土短柱进行轴压试验;探讨橡胶粉体积取代率和橡胶粉粒径对其力学性能的影响,给出了方钢管橡胶混凝土轴压承载力计算公式.结果表明:随着橡胶粉体积取代率的增加,方钢管橡胶混凝土极限承载力和刚度均有下降的趋势;随着橡胶粉粒径的增大,方钢管橡胶混凝土极限承载力和刚度也有所下降;由本文给出的轴压承载力计算公式所得到的计算结果与试验结果总体上较为吻合,可用来预测方钢管橡胶混凝土的截面强度.     

薄壁钢管混凝土短柱与薄壁钢管约束混凝土短柱轴压性能试验

以圆形和方形薄壁钢管混凝土短柱及薄壁钢管约束混凝土短柱为对象，研究了外包钢管受力状态对短柱性能的影响及其机理，分析了截面形状对外包钢管受力状态及其对核心混凝土约束的影响。通过CFRP约束对受力性能的研究，进一步揭示了外包材料受力状态对受力性能的影响。研究表明，圆钢管对核心混凝土约束作用强，试件极限承载力较高，其中圆钢管约束柱中钢管的约束作用更加显著，极限承载力大于圆钢管柱；CFRP约束后，极限承载力和变形性能均得到有效改善。方钢管对核心混凝土的约束效果弱，试件极限承载力较低，且方钢管约束柱的极限承载力小于方钢管柱；CFRP约束对其极限承载力无明显提高，但有效改善了其延性。     

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.