天然气脱硫催化器扩张角对流场的影响

为了使含有硫化氢的天然气尽可能均匀地通过整个催化剂载体,以提高天然气脱硫催化器转化效率和使用寿命,文章利用Fluent软件对催化器进行了二维流动数值模拟。结果表明,长渐扩管结构的流动特性明显优于短渐扩管结构;随着扩张角α增大,催化器流速分布均匀性逐渐变差,当扩张角增大到一定程度时,扩张角α对流速分布影响变得很小。     

某航空燃油喷嘴雾化特性分析及结构优化

燃油雾化在航空发动机预混燃烧过程中起着至关重要的作用.为提高某航空燃油喷嘴的雾化特性，改进和优化其结构参数，采用流体体积(VOF)界面捕捉算法和正交试验设计相结合的方法，研究了喷嘴的内部流动及结构参数(扩张角、直线段长度、旋流槽升角、旋流槽个数)对雾化特性的影响规律.结果表明：旋流槽上的局部漩涡影响喷嘴内部燃油流动，通过改变旋流槽入口的结构形式消除局部压力损失；旋流槽个数对索特尔平均直径(SMD)的影响最为显著，扩张角是影响雾化锥角最大的因素，存在一个最优的旋流槽升角使油膜厚度最小，直线段长度对雾化特性的影响相对较小；当扩张角为60°、直线段长度为0.25 mm、旋流槽升角为45°、旋流槽个数为2时，优化效果最佳.优化后的喷嘴油膜厚度减小了43.68%,雾化锥角增加了3.70%,SMD减小了14.79%.     

机械密封冲洗液限流器的试验研究

用水、煤油、机油及柴油先后对孔板、喷嘴、弯头、限流管和限流阀等五种型式限流器进行了试验，得出一些规律和可供限流器设计和使用时必要的性能和设计数据。从流动角度来看在相同口径下孔板的流量系数最大，限流管的流量系数最小．喷嘴、弯头和限流阀等的流量系数居中；从使用角度来看，限流阀简便、使用灵活，可以调节流量和控制工况，而限流孔板最复杂、易堵且不可调节与控制工况。     

临界攻角下锯齿尾缘压气机叶片气动特性

基于Smagorinsky亚格子应力模型的大涡模拟,研究不同攻角下某型压气机叶栅的性能变化规律,获得临界攻角.分析临界攻角下不同齿高比(1.0~2.0)的锯齿尾缘叶片的气动特性及锯齿结构抑制流动分离的物理机理.研究表明:当攻角增至临界攻角时,叶栅的升压、扩压能力达到最大值,但此时伴随着流动分离、涡脱落等复杂流动现象,导致流动损失增加;锯齿尾缘结构能够改善叶片吸力面的流动分离,从而有效地减少吸力面边界层的厚度,延缓叶片失速,并能在不影响压气机增压能力的情况下降低损失;综合考虑流动损失及增压、扩压能力,齿高比在1.2左右时锯齿叶片的性能最佳;相较于基准叶片,最佳锯齿叶片的扩压能力基本相同,但是至少可以减少28.1%的流动损失,并提高1.2%的增压能力.     

在线监测系统中音速喷嘴的数值模拟分析

为提高在线监测系统(CEMS)中音速喷嘴的计量精度，通过纯气体组分条件下圆环形喉部音速喷嘴的数值模拟研究，建立了关于流出系数与扩散段参数、气体种类以及雷诺数关系的BP神经网络模型，分析了临界背压比与喉部雷诺数的关系，预测了CEMS音速喷嘴的流动特性，并与实验结果进行对比.结果表明，BP神经网络方法与数值模拟方法均可对喷嘴流量进行合理预测，最大误差仅为1.004%.当喷嘴喉径由0.143 2 mm增加至0.350 2 mm时，临界背压比较数值模拟值降低约20%.BP神经网络模型可以快速有效地预测CEMS音速喷嘴采样流量，当雷诺数大于4 000时临界背压比显著下降.     

钻井中双级流量分配的理论研究

双级分流系统由导眼体喷嘴组、扩眼体喷嘴组、级间钻柱中心孔和级间环空组成，为一个并联流道系统。推导出了双级流量分配公式，确立了双级流量分配的基本原则，并应用公式对导眼体分流流量进行了参数变化影响规律分析，在其他参数不变的条件下推导出了描述喷嘴组的当量直径和级间段长与导眼体分流流量间的简化关系式。结果表明，导眼体和扩眼体喷嘴组的当量直径对导眼体分流流量影响较大，是调整双级分流的主控因素；级间段长对其影响较小，在喷嘴组设计时给予适当考虑，在两级之间加钻柱时。导眼体的清洗是能保证的；钻铤内径、钻井液表观粘度、喷嘴流量系数对其影响很小，钻井液密度、井眼扩大系数、钻铤外径的影响则更小。     

带盖板预旋系统流动与温降特性的数值模拟

为了研究带盖板预旋系统的流动与温降特性,对不同喷嘴角度和不同转速(工况)下的预旋结构模型进行了数值模拟。在相同进气条件下,研究了有无预旋结构和不同喷嘴角度下的盘腔流动与温降特性,分析了旋转雷诺数对系统流动情况和温降效果的影响。结果表明：预旋结构在盖板腔内产生的漩涡增强了盘腔的流动,相比于无预旋结构,其盖板腔压力和系统出口总温明显降低;随着喷嘴角度的增大,盘腔总温和静压均增大,温降效果变差;随着旋转雷系诺数的增大,无量纲质量流量增大,无量纲温降和总压损失系数均减小;预旋角由50°减少到30°时,系统无量纲温降增加了23.7%。     

轴对称凝固锭中通道偏析的形成与防止

用　Ｐｂ－５％Ｓｎ合金在垂直轴对称凝固的　φ７０　ｍｍ×１２０ｍｍ圆柱锭上模　　拟了大型钢锭中Ａ偏析的形成，研究了Ａ偏析形成的临界导热条件。采用倾　　角低速旋转法对轴对称凝固条件下通道偏析的防止作了初步尝试。结果表　　明：通道偏析的形成条件是径向温度梯度大于７．５×１０－２°Ｃ／ｍｍ；凝固速度　　小于临界凝固速度，临界凝固速度随着温度梯度的降低而降低。倾角低速旋　　转可以有效地防止通道偏析的形成。当铸锭沿轴线倾斜２２°时，相对于绕垂直　　轴旋转，防止偏析所需的转速可降低８０％．     

不同偏流板侧转角对回流的影响规律

偏流板将飞机发动机尾流导向，防止尾流烧蚀地面或损坏周围设备和建筑，但是偏流板会产生回流，不利于发动机正常工作。以简化发动机模型和偏流板为对象，研究了双发飞机起飞时偏流板侧转角对回流的影响。结果发现侧转角较大时，近地面回流到达发动机尾流下方时，由于主流引射作用会向发动机外侧发生第一次偏转，侧转角越大，偏转越明显；存在一个临界侧转角6°，小于6°时，回流第一次偏转后沿着发动机下侧向前流动，易被进气道吸入；大于6°后，近地面回流一次偏转后会向发动机的外侧进一步偏转，最后向后流动，不会被进气道吸入。同时，随着侧转角增大，更多的高温尾气回流向一侧偏转，有利于另一侧人员和设备的安全。     

涡轮叶栅叶顶间隙泄漏流动实验研究

针对一种高负荷涡轮叶栅,利用低速矩形叶栅风洞实验研究叶顶间隙泄漏流动．研究了不同叶顶间隙和不同来流冲角情况下,涡轮叶栅的流场结构和气动性能．研究工况包括无间隙,0.5%、1.0%、1.5%叶高间隙和±10°、±5°、0°冲角．通过五孔探针获得矩形叶栅出口截面上总压、气流角以及速度分布;通过叶片表面开设的静压孔,获得叶片中部以及靠近叶顶截面的叶片表面静压分布．实验结果表明:叶顶间隙的存在增强了叶栅顶部的二次流动,恶化了上半叶展的流动状况,涡系结构发生了改变．随着叶顶间隙的增大,叶栅总压损失增加,气流偏转不足/过偏现象加剧;随着冲角的增大叶栅总压损失增加．     

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.     

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.     

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。     

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.