宽尾墩阶梯溢流坝出闸室水舌下缘挑距水力计算

将宽尾墩安置在阶梯溢流坝上游,形成宽尾墩和阶梯溢流坝面相结合的消能设施,水流具有其独特的特点.结合索风营水电站宽尾墩后接台阶式溢流坝消能设施的物理模型实验和数值模拟结果,对出闸室抛物型跌落射流进行了研究,综合出闸室水流的影响因素给出了水舌下缘挑距的计算关系式,分析了堰面坡度和挑坎高度对挑距的影响,并利用已建类似工程的实验数据进行了验算.结果表明,给出的计算公式可供估算类似工程水舌下缘挑距参考应用.     

重力坝下游宽尾墩联合消能工三维数值模拟

宽尾墩消力池在水利枢纽工程中已经得到广泛的应用,而中高水头宽尾墩消力池内部流场较为复杂,运用物理模型试验结合数值模拟旨在实现水利工程中消能工体型优化的目的。针对物理模型试验难以得到的详细的各项水力学指标,采用RNGk-ε双方程紊流模型和VOF方法对宽尾墩消力池联合消能工的泄洪流场进行三维数值模拟,获得了泄洪流态、流速、水面线、坝面、闸墩和消力池底板压强的分布规律。数值模拟计算和物理模型试验数据的对比分析研究,两者吻合较好,表面数值模拟分析方法能满足工程需求。     

宽尾墩消能工的研究进展

宽尾墩是一种广泛应用的收缩式消能工,不同工程需要不同体型的宽尾墩消能工.墩型的选择直接影响水流流态、坝面、宽尾墩的墩体压力,以及消能效果等.该文对宽尾墩消能工的种类,以及各种宽尾墩消能工的消能效果进行介绍.     

低水头非完全宽尾墩三维流场数值模拟

为解决常规物理模型试验受观测手段限制难以全方位研究深尾水消力池内水力学参数的问题,借助RNGk-ε紊流模型结合VOF方法对比研究深尾水作用下平尾墩及非完全宽尾墩试验方案下游消力池内流场变化,并揭示非完全宽尾墩消能机理.研究结果表明:受溢流堰纵向长度及下游消力池内深尾水限制,平尾墩底流式淹没水跃逼近溢流堰顶,消力池内消能紊动不足,出池水流形成强烈二次水跃;非完全宽尾墩则束窄部分溢流堰闸室过流断面促使形成纵向拉伸挑射水舌,利用各相邻闸室非对称出闸水流、增强消力池内入池水流横向流速梯度和水位落差,加剧消力池内入池水流横向扩散、交汇,在消力池上游区域形成由底层至表层的大幅度立轴旋滚,显著增强消力池内能量耗散,降低出池水流流速,取得较好的消能效果.     

索风营电站新型泄流建筑物水力特性分析

索风营电站采用了宽尾墩 阶梯溢流坝的坝面泄流形式，这种坝面泄流形式由我国首创，虽在实际工程中有所应用，但缺少3维数值计算成果．紊流数值模拟计算了在设计水位条件下的掺气情况、压力分布、紊动动能和紊动耗散率等水力特性，表明宽尾墩 阶梯溢流坝的坝面泄流形式使高水头大单宽泄流有了突破性的进展．数值计算时单宽过量已达141m^3／s．m．     

T型墩的应用及消能效果

通过总结多项工程T型墩消力池的研究成果和原型观测,对T型墩的水力特性,特别是池内流态及尾水适应条件进行了分析,与平底消力池的池长、池深及消能率进行了对比,并通过原型观测进行了验证,结果表明:T型墩消力池结构紧凑,消能效率高,消能效果良好以及尾水波动小、经济效益好,是一种适合于中、低水头的较理想的消能形式。     

新疆五一水库溢洪洞底流消能模型试验研究

根据工程建设需要,对新疆迪那河五一水库溢洪洞消力池消能进行模型试验。对其消能防冲的布置从调整梯形墩位置个数、尾坎高度、T型墩位置个数等不同角度出发进行试验。根据试验结果,提出采用了梯形墩和悬栅联合布置的最佳设计方案。梯形墩和悬栅的联合运用为辅助消能工的结构设计和其他同类工程优化消力池提供参考。     

低水头条件下常用底流消力池的对比研究

低水头消能工常常存在水流佛氏数小、消能效率低等问题,为此常在底流消力池中添加辅助消能工以求达到良好的消能效果.国内外常用的低佛氏底流消力池有USBR-Ⅳ型、ISI型、SAF型和T型等4种型式.文章采用k-ε方程紊流模型并结合VOF追踪自由水面法,通过数值模拟对上述池型各自的消能效果、流态分布、工程造价等方面进行对比研究...     

低水头泄水建筑物消能防冲研究

某低水头泄水建筑物采用宽尾墩与消力池联合消能工,并在护坦上增设两排消力墩,利用三元流的水力特性增强了消能效果,且在常遇洪水工况下护坦齿坎淘深与河床中部冲深分别减小了58％和34％．研究结果表明,采用适当的辅助消能工能有效地解决低水头泄水建筑物的消能防冲问题．     

悬栅消力池内水跃的数值模拟

悬栅消力池是一种能够降低池内最大水深的新型消能设施.为了探索悬栅消力池的作用机制,采用标准k-ε湍流模型对悬栅消力池和无悬栅的消力池内水跃进行了二维数值模拟,自由水面采用VOF方法确定,得到了消力池内水跃的流场结构、自由水面和底板压强分布.实测结果验证了数学模型和数值方法的合理性.通过两种消力池计算结果的对比,对悬栅消力池为何能够降低池内最大水深和提高消能效果提出了解释.     

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.     

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.     

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.