分支管面积对Π型并联管组的水动力计算结果影响

在并联管组水动力学基本方程的基础上,分别采用水动力推进算法和水动力标准算法,对3种不同的分支管面积的Π型集箱进行计算,比较两种算法的计算结果差异.计算结果对确定水动力标准算法的适用范围有重要意义.     

航行船与停泊船水动力相互作用的数值分析

采用动网格技术并选取RNGk-ε湍流模型,通过求解非定常RANS方程,对浅水中航行船与停泊船相互作用的三维非定常黏性流场进行了数值分析.计算了停泊船受到的水动力,通过将计算结果与经验公式结果进行对比,验证了本文采用的数值计算方法的有效性;计算了航行船所受水动力,比较了作用在航行船和停泊船上的水动力的大小.最后,计算了不同水深、两船间距、停泊船离岸距离和航行船离岸距离条件下停泊船受到的水动力,并对计算结果进行了分析,得出了以上4种因素对停泊船受到的水动力作用的影响规律.     

对转桨非定常水动力性能的数值分析

基于速度势的面元法预报了对转桨的非定常水动力性能,采用周向平均的方法处理转桨的两桨之间的干扰.首先通过将定常计算值与文献值进行比较验证算法的可靠性.然后,进一步分析了对转桨的非定常水动力性能,并将计算值与实验值和文献值相比较.结果显示:非定常结果与文献值非常接近,而且在加入伴流场后,非定常计算值比定常计算值的精度更高.计算了对转桨不同方向上的非定常力和力矩,分析表明该方法在计算对转桨水动力性能方面有一定适用性.     

用非定常面元法预报拖式吊舱螺旋桨水动力性能

用非定常面元法对拖式吊舱推进器的水动力性能进行求解,吊舱和螺旋桨的相互干扰通过诱导速度迭代处理.与将相互诱导速度在周向上进行平均的处理方法相比,文中的方法真实考虑了螺旋桨和吊舱相互影响的非定常性.为了节省计算时间和存储空间,对螺旋桨的求解只在主叶上进行.结果表明,该方法能够对吊舱推进器在均匀来流和在非均匀来流中的水动力性能进行计算.将敞水条件下的计算结果同试验结果进行了比较,两者有较好的一致性.     

深水浮式海洋平台水动力性能计算研究

在以边界元方法（BEM）和计算流体力学方法（CFD）构建的软件平台基础上,实现了有关深水浮式海洋平台设计中诸多水动力性能计算,包括波浪中的运动响应与荷载计算、砰击荷载预报、气隙校验、立管动力响应分析、系泊与动力定位系统评价,以及出入水问题的解与工程应用等.所有算例计算表明,计算或预报结果具有工程应用精度,可以为工程设计提供参考.     

基于GPU并行算法的水动力数学模型建立及其效率分析

应用非结构化网格建立水动力模型目前已经得到了广泛的应用.针对在网格数过多,且无集群机情况下难以快速获得计算结果这一问题,基于GPU的高性能计算技术,在CUDA开发平台下设计并行算法,建立非结构化网格的二维水动力模型.与利用GTX460显卡和集群机的计算效率对比表明,在保持计算精度的前提下,速度提升了一个量级,且随着网格数的持续递增,可以保持较高的加速比增幅,比较适合应用于大范围海域的水动力模型的数值计算.     

船舶操纵粘性流求解器的开发与应用

介绍了基于求解雷诺平均纳维-斯托克斯(RANS)方程的分区网格船舶操纵粘性流求解器,以及应用该求解器计算船舶操纵相关的粘性流动与水动力的研究工作.计算了舵的粘性流场和水动力,所预报的舵升力曲线和阻力曲线在舵角未达到失速角前,与现有的试验和计算结果符合良好,所预报的舵失速角稍偏小.还计算了6∶1椭球体和Wigley船体做大角度定常斜航运动时的3维粘性流场及水动力,正确地模拟这种以层流/湍流分离流为主的复杂粘性流动,从而检验和验证了该求解器精确模拟粘性分离流动和计算水动力的能力.     

基于非定常边界元法的振动翼水动力性能研究

讨论了非定常边界元法的构建过程、数值模型、程序结构,建立了可以计及自由面影响的振动翼水动力性能计算模型;并采用该法在时域中进行了计算和研究.计算中采用了时变的尾涡面和时步迭代法.基于格林定理在边界面上布置Rankine源和偶极子,并采用时域方法求解自由面问题.经过数值计算结果与试验数据的对比,验证了计算模型的可行性和可靠性,表明该方法是研究振动翼非定常水动力性能的有效算法.     

调距桨的桨叶畸变对其水动力性能的影响分析

为了研究调距桨的桨叶畸变规律和畸变对桨水动力性能的影响,采用面元法对调距桨不同调距角下的畸变和水动力性能进行了计算和分析.首先,以JDC7004桨为对象,计算了其在调距角为0°时的水动力性能,并将计算结果与实验值对比,验证了计算方法的准确性;然后,采用坐标变换原理模拟了叶元体的畸变,结合面元法计算了畸变后叶元体的压力系数分布,进而求解了发生畸变和不发生畸变两种情况下桨的推力、转矩、转叶力矩和敞水效率,并对比分析了畸变对水动力性能的影响;最后,探讨了调距桨的侧斜角、纵倾角和盘面比对叶元体的畸变影响.结果表明:正车和倒车工况引起的桨叶畸变对叶元体表面压力分布和桨的各水动力系数的影响规律并不相同,对空泡性能的影响截然相反;畸变对桨叶的转叶力矩的影响较小,对敞水效率的影响较大,设计阶段考虑畸变有利于改善调距桨的水动力性能.     

拖式与推式吊舱推进器水动力性能数值仿真及对比

为研究吊舱推进器在直航和回转工况下的推进性能,通过RANS方法结合标准k-ε湍流模型对拖式与推式吊舱推进器在不同工况下的水动力性能进行对比分析.分别计算拖式与推式吊舱推进器直航与回转工况下的推力系数与转矩系数,并与试验结果进行对比以验证数值计算的准确性.直航工况推进特性曲线、回转工况的推力系数与转矩系数曲线对比结果表明,数值计算可以准确预报吊舱推进器的水动力性能.根据该模型计算了斜流工况时两种推进器的推力、转矩系数以及轴向力和侧向力系数随角度的变化规律.结果表明,本文提出的水动力模型可以准确预报不同工况下吊舱推进器的水动力性能.     

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.     

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。     

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.     

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.