大直径双钢筋砼受弯构件刚度试验

研究不同梯格尺寸双钢筋筋试验梁的工作特性，确定用冷拉螺纹钢筋制作双钢筋的合理梯格及加工工艺参数，分析用Φ’１２双钢筋配筋的双钢筋砼受弯构件的刚度，提出大直径双钢筋砼受弯构件的刚度计算公式，并分析其裂缝发展特征。     

梯形钢筋混凝土梁变形控制的试验研究

为了充分发挥双钢筋的技术优势,拓宽双钢筋技术的使用范围,对采用直径为14mm的热轧带肋三级钢筋焊制大直径双钢筋的构件作了分析研究.重点研究了大直径双钢筋受弯构件的刚度及变形计算,同时从粘结机理角度分析了双钢筋工作机理,对双钢筋构件的变形特征作了较完整的理论解释,并提出了相应的大直径双钢筋混凝土构件的刚度建议计算公式.     

梯形钢筋混凝土梁变形控制的试验研究

为了充分发挥双钢筋的技术优势，拓宽双钢筋技术的使用范围，对采用直径为14mm的热轧带肋三级钢筋焊制大直径双钢筋的构件作了分析研究。重点研究了大直径双钢筋受弯构件的刚度及变形计算，同时从粘结机理角度分析了双钢筋工作机理，对双钢筋构件的变形特征作了较完整的理论解释，并提出了相应的大直径双钢筋混凝土构件的刚度建议计算公式。     

长期受弯构件应力应变分布及变形规律研究

通过全面考虑混凝土徐变收缩、裂缝影响及应力重分布变化过程,推导了适于不同应力分布条件下钢筋混凝土受弯构件截面长期应力应变分布规律的计算方法.提出了钢筋混凝土构件收缩翘曲变形影响系数曲线及曲率计算公式,并建立了分析预测受弯构件初始及长期总变形的通用分析方法.考虑截面非线性应力分布曲线,对各类受弯构件长期徐变收缩效应及变形进行分析,通过了试验验证.研究归纳了配筋率、截面尺寸等影响受弯构件长期挠度变化规律的主要因素.分析表明,钢筋能有效约束受弯构件长期徐变变形,而收缩翘曲变形大小及方向则主要取决于拉、压钢筋配筋率比值;在同等的初始抗弯刚度或截面积条件下,宽扁梁长期变形增长较普通梁显著.     

断裂力学方法分析钢筋混凝土的抗裂度

采用断裂力学的方法,通过有限元分析,提出钢筋普通砼和钢筋陶粒砼受弯构件抗裂度计算公式。该方法全面考虑了砼强度等级、配筋率、受拉钢筋位置、试件尺寸效应对钢筋应力的影响,对大尺寸试件用Weibull尺寸效应反映,既考虑截面高度又考虑截面宽度的影响,计算更为合理。用此抗裂度计算公式对33根梁的计算结果与试验符合良好。本文公式不仅能解决一般受弯构件的抗裂度计算问题,同时可对带有较大显著裂缝(包括构造缝)的剩余截面进行抗裂度计算。     

大直径高强预应力筋混凝土梁承载能力数值分析

目的研究大直径高强钢绞线预应力混凝土梁受力性能,进一步扩展大直径高强预应力筋在实际工程中的应用范围.方法以直径为17.8 mm的1860级钢绞线作为预应力筋,普通钢筋作为非预应力筋,设计制作了6根大直径高强钢绞线预应力混凝土简支梁.试验梁进行三分点加载试验,基于相关试验数据和数值分析方法,对大直径高强钢绞线预应力混凝土梁进行受弯承载力非线性研究,探讨预应力筋配筋率、非预应力配筋率、预应力筋强度指标和混凝土强度等级等参数对模拟梁构件承载力影响规律.结果预应力筋配筋率的提高即能够明显改善预应力混凝土梁构件变形性能,又能提高梁构件承载能力;混凝土强度等级与非预应力配筋率是影响梁构件受弯承载力的重要因素.结论通过对大直径高强预应力筋混凝土梁构件的参数分析,为工程实践提供依据的同时,也为其更广泛的技术应用提供设计参考.     

冻融和锈蚀环境下混凝土受弯构件的刚度计算模式研究

针对东北寒冷地区混凝土结构耐久性问题开展试验研究,分析了冻融循环和钢筋锈蚀共同作用下钢筋混凝土受弯构件的受力性能,揭示了冻胀现象和钢筋锈蚀对钢筋混凝土受弯构件抗变形能力的影响规律,并建立了冻融和锈蚀环境下混凝土受弯构件的刚度计算模型,经试验验证、分析对比结果表明,计算模型合理可行.     

受弯构件截面形状对工程造价的影响研究

通过对矩形、工字形、T形、圆形和环形等5种截面形状受弯构件进行对比分析,研究了不同截面形状对工程造价的影响.计算了T形受弯构件和环形受弯构件在不同截面尺寸比例下的抗弯截面系数,得出了承载性能随截面尺寸比例的变化规律,从而可通过调整受弯构件截面尺寸比例对工程造价进一步优化.     

钢筋混凝土箱形截面受弯构件最小配筋量的计算

基于莫氏假定,考虑到箱形截面顶、底板几何尺寸对开裂弯矩的影响,推导了钢筋混凝土箱形截面受弯构件纵向受拉钢筋最小配筋量计算公式,该公式同样适用于矩形、I形、T形等常见类型截面.对一单箱单室钢筋混凝土箱梁最小配筋量的计算表明,现行公路桥规对钢筋混凝土箱形截面受弯构件最小配筋量的规定偏低.最后对土木工程中常见的箱形截面受弯构件,提出计算箱形截面受弯构件纵向受拉钢筋最小配筋量的简化计算公式.     

小尺寸钢筋混凝土梁模型实验

受到试验仪器及试验费用的限制,利用小尺寸钢筋混凝土梁模型对钢筋混凝土构件的各种性能进行研究是十分必要的.本文主要针对小尺寸钢筋混凝土梁模型试验展开研究.首先根据实验室加载设备设计钢筋混凝土梁模型的尺寸,之后对该混凝土模型梁进行纵向受拉钢筋及箍筋设计,最后将制作好的混凝土模型梁在实验机上进行四点受弯试验.试验结果表明小尺寸钢筋混凝土构件是能够发生混凝土梁的典型破坏,进而能够反映混凝土梁的各种力学性能.     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

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