材料强度对深梁滞回性能影响的有限元分析

钢板深梁作为一种新型的耗能构件,可以实现宽范围的刚度渐变调幅。通过用ANSYS10.0对由Q235、Q345与Q420三种不同强度的材料制成的钢板深梁施加低周反复荷载进行有限元模拟分析,研究了其破坏过程和破坏机理,得到了深梁的滞回曲线、延性及承载力衰减系数和能量耗散系数。有限元模拟分析说明随着钢材强度的提高钢板深梁中钢板的耗能能力有所下降。     

环梁式圆钢管约束H型钢混凝土柱-钢梁 节点的抗震性能

设计了一种环梁式圆钢管约束H型钢混凝土柱-钢梁节点,并建立了该试件的全尺寸三维有限元分析模型,计算得到了此类节点试件的滞回曲线、骨架曲线及破坏模式,经与试验结果进行对比,两者吻合良好.在此基础上,对试件进行有限元变参数分析,考察了轴压比、混凝土强度、梁柱线刚度等对试件抗震受力性能的影响,同时提出了一种改进型梁端削弱翼缘的节点形式.结果表明:随轴压比增大,试件的耗能及延性性能明显下降;混凝土强度的变化对试件滞回性能影响不大;当保持柱截面不变,仅变换钢梁尺寸时,节点的承载力、延性及抗震耗能性能均随梁-柱线刚度比的增大而显著增大;而当保持钢梁截面不变,仅改变柱内型钢含钢率时,节点抗震受力性能随梁-柱线刚度比的变化并不明显;改进的梁端翼缘削弱形式的试件可在不明显降低其承载力及耗能性能的情况下,将塑性铰外移至距节点区较远的地方,从而更好地保护节点区.上述研究结论可为此类新型节点的应用提供理论基础.     

环向均匀脱空对圆钢管超高强混凝土柱偏压受力性能的影响

为研究环向均匀脱空对圆钢管超高强混凝土柱偏压受力性能的影响,通过环向均匀脱空圆钢管超高强混凝土柱的偏压试验,研究环向均匀脱空圆钢管超高强混凝土柱的承载能力、延性和破坏模式.结果表明:随着偏心率的减小,钢管局部屈曲的发生时刻提前,试件的延性减小;环向均匀脱空试件的初始刚度与无脱空试件的初始刚度基本相同;混凝土压溃位置与钢管局部屈曲位置基本一致,压溃程度随偏心率的减小而增大,与无脱空试件相比,环向均匀脱空试件的混凝土破碎更加严重;偏压试件的受拉裂缝近似沿中截面对称分布,裂缝长度和宽度随偏心率的减小而减小;无脱空和环向均匀脱空对圆钢管超高强混凝土柱承载力计算公式与实测结果吻合良好.     

圆钢管再生混凝土柱抗震性能试验

为研究圆钢管再生混凝土柱的抗震性能,考虑不同再生粗骨料取代率、剪跨比、轴压比等参数,设计了7个足尺试件,进行拟静力试验研究,对比分析了各试件的破坏特征、滞回曲线、承载力、延性、刚度退化、耗能能力等特性.试验结果表明:加载后期,所有试件均在钢管底部出现环状鼓曲,剪跨比小的部分试件受拉一侧发生断裂;各试件的滞回曲线基本呈梭形,比较饱满,延性较好;不同粗骨料取代率对试件的抗震性能影响不大;随着剪跨比的增大,试件的承载力降低,延性变好;轴压比大的试件延性较差;各试件抗震性能良好,满足抗震要求.通过我国相关规范和规程对本文及其他文献中圆钢管再生混凝土柱压弯承载力的计算分析发现,对于足尺圆钢管再生混凝土柱,我国规范的相关公式是偏于安全的.     

CFRP约束圆钢管高强混凝土短柱轴压试验研究

为研究混凝土强度、径厚比、CFRP(碳纤维增强复合材料)层数及CFRP包裹方式等参数对CFRP约束圆钢管混凝土轴压静力性能的影响,进行了6个圆钢管混凝土短柱和18个CFRP-钢管混凝土短柱的轴压对比试验.研究发现CFRP的约束对圆钢管混凝土承载力有较显著的提升,且承载力的提高幅度随着CFRP的增加而增加.钢管高强、超高强混凝土短柱的破坏形态呈现为剪切破坏,延性较差,CFRP的约束可以改善其延性,且CFRP层数越多延性越好.半包CFRP试件性能接近于全包CFRP试件性能.随径厚比增大,CFRP约束效果下降.若黏结良好,试件失效前,CFRP与钢管能保持协同工作;最后选取了3个经典的CFRP约束钢管混凝土轴压承载力公式进行验算,发现基于CFRP和钢管双重约束的公式能较好地预测其承载力.     

圆钢管高强再生混凝土柱抗震性能试验

设计并制作4根钢管高强再生混凝土圆柱,考虑再生粗骨料取代率单参数,对其进行拟静力试验,观察它们在试验过程中的受力和破坏形式;研究不同再生粗骨料取代率对试件的滞回曲线、骨架曲线、承载力和延性、耗能性能、刚度退化等抗震性能的影响.结果表明:圆钢管高强再生混凝土柱的受力和变形与普通圆钢管高强混凝土柱的基本相同,滞回曲线普遍饱满,没有出现捏拢现象;再生骨料取代率对试件初始刚度略有降低,对试件的耗能、承载力以及后期的刚度退化影响不大;对比普通圆钢管高强混凝土柱,圆钢管高强再生混凝土柱的延性系数较大,具备良好的抗震性能.     

内衬管螺纹连接中空圆钢管混凝土的轴压性能实验

提出采用内衬管和螺纹连接方式连接长圆钢管混凝土。以螺纹的长度、深度和位置为基本参数设计12个内衬管螺纹连接中空圆钢管混凝土短柱,并进行轴压试验,分析不同参数对试件轴压承载力和刚度的影响。结果表明,试件的轴压力-纵向压缩量曲线可以划分为弹性阶段、弹塑性阶段和下降段。内衬管螺纹连接试件的承载力和刚度与无连接试件或者焊接试件基本持平。在本文的研究参数范围内,端截面内衬管螺纹连接试件的承载力和刚度均高于中截面内衬管螺纹连接试件,试件的承载力和刚度随着螺纹长度与深度的增加而增大。依据理论计算结果与实验结果的对比,给出内衬管螺纹连接圆中空钢管混凝土轴压承载力计算方法的建议。     

螺栓连接装配式混凝土梁静力性能有限元分析

目的研究型钢厚度、混凝土强度及型钢截面形式对螺栓连接装配式混凝土梁的静力性能影响.方法采用ABAQUS软件,对螺栓连接装配式混凝土梁进行有限元分析,得到螺栓连接装配式混凝土梁的静力性能随混凝土强度、型钢厚度及型钢截面形式的变化规律.结果螺栓连接装配式混凝土梁的极限承载力、屈服位移随着混凝土强度和型钢厚度的增加而增加;相同工况下,预埋矩形型钢试件极限承载力,屈服位移大于预埋工字型型钢试件.结论螺栓连接装配式梁节点构造合理,满足结构设计使用要求.综合考虑材料及造价等因素,建议工程中采用C30混凝土、预埋30 mm厚度工字型钢试件.     

带圆钢管劲性高强混凝土轴压短柱试验研究

介绍了包括带圆钢管的劲性高强混凝土轴压短柱、钢管高强混凝土短柱以及普通高强混凝土短柱在内共13个试件的轴心受压试验,主要研究了带圆钢管的劲性高强混凝土轴压短柱的破坏特征、延性和极限承载力.研究结果表明,核心圆钢管的存在,改善了高强混凝土短柱的轴压性能;短柱中的混凝土与钢管能够共同工作直到破坏,其极限强度可以用叠加原理计算.     

圆钢管轻集料混凝土抗弯性能的有限元分析

文章介绍了圆钢管轻集料混凝土受弯构件的有限元分析方法,在试验研究的基础上,采用有限元软件ANSYS对试验试件进行模拟计算,并且分析了含钢率、钢材屈服强度和轻集料混凝土强度等参数对构件弯矩-曲率关系曲线的影响。计算分析结果表明,计算所得极限荷载和弯矩-曲率关系曲线与试验结果吻合较好;含钢率是影响构件抗弯性能的主要因素;钢材屈服强度对构件的抗弯刚度影响很小,但对其抗弯承载力影响明显;轻集料混凝土强度对圆钢管轻集料混凝土构件的抗弯承载力与抗弯刚度影响甚小。     

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.