提速线路轨道不平顺波长的动力仿真

基于耦合动力学理论,利用有限元方法建立了车辆-轨道耦合系统振动分析模型,输入不同截止波长的不平顺数据进行动力仿真计算,以确定轨道不平顺管理波长范围.高低不平顺主要影响车体的沉浮和点头运动,引起车体垂向加速度增大;轨向不平顺主要影响车体的侧滚和摇头,引起车体横向振动加速度增大.长波不平顺的影响主要体现在车体振动上,因此本文选定车体加速度作为确定不利波长的判定指标,对提速线路200km/h和250km/h速度下轨道不平顺波长管理的范围进行了探讨,并提出了提速线路轨道不平顺波长管理的建议.     

双向隔震铁路桥梁与列车的耦合振动响应研究

为了研究铅芯橡胶双向隔震铁路桥梁在列车荷载作用下的动力性能,本文首先建立一座三跨隔震桥梁三维模型,然后对双向隔震铁路桥梁和列车组成的车桥系统耦合振动进行分析,研究其机理.结果表明,隔震桥梁在横桥向的隔震周期越大,桥梁梁体在列车荷载作用下横桥向位移越大,支座阻尼对桥梁梁体横桥向水平振动的衰减作用更加明显,对桥梁上部结构扭转角和竖向位移的影响可以忽略不计.桥梁横桥向的隔震周期的增大,使车体横摆、侧滚振动位移响应更加剧烈,对车体各个自由度的加速度响应影响可以忽略不计;隔震支座阻尼的增大对车体横摆、侧滚角、摇头角、沉浮和点头角位移响应以及对车体各自由度的加速度响应影响较小.     

设置双向隔震支座铁路桥梁的耦合振动响应

利用有限元软件ANSYS建立了一座三跨隔震桥梁三维模型,并利用Matlab编制双向隔震铁路桥梁和列车组成的车桥系统耦合振动分析程序,研究了铅芯橡胶双向隔震铁路桥梁在列车荷载作用下的动力性能.分析结果表明:隔震桥梁在横桥向的隔震周期越大,桥梁梁体在列车荷载作用下横桥向位移越大,而扭转角和竖向位移变化不明显;桥梁横桥向的隔震周期较大时,支座阻尼对列车作用引起的桥梁梁体横桥向水平振动的衰减作用更加明显;随着桥梁横桥向隔震周期的增大,车体横摆、侧滚振动位移响应显著;隔震支座阻尼对车体横摆、侧滚位移响应有一定的衰减作用;横桥向的隔震周期和隔震阻尼比的不同对车体摇头、沉浮和点头位移响应影响较小.     

既有高速铁路提速条件下低频晃车特征及影响因素研究

针对某高速铁路列车在运营速度由200 km/h提升至250 km/h后,部分直线区段出现的车体横向低频晃动现象开展试验研究和仿真分析。首先对比分析提速前、后轨道动态检测数据在晃车区段和未晃车区段的时频特征以及乘坐舒适性,进而研究晃车区段的轮轨接触特性,通过建立车辆-有砟轨道动力相互作用模型,深入分析轮轨廓形、列车运行速度以及轨道平顺状态对高速铁路直线运行晃车问题的影响。研究结果表明：当列车提速至250 km/h后,晃车区段车体横向加速度出现明显周期性波动,振动频率为1.37 Hz,与提速前相比,车体横向加速度振动幅值增加了一倍,舒适性等级接近超限,乘坐舒适性明显降低;与采用CHN60&LMA廓形相比,采用实测轮轨廓形时的轮对蛇形运动加剧,轮对运动向一侧钢轨偏移,直接影响车体横向振动频率;列车运行速度提高后车辆系统响应对轮轨廓形的变化更为敏感,采用实测轮轨廓形,列车运行速度为250 km/h时的车体横向加速度谱峰较运行速度为200 km/h时的增大了1.6倍,较采用CHN60&LMA廓形时的增大了1.5倍;当列车提速至250 km/h后,轨道不平顺振动频率与轮对蛇形运动频...     

地震引起的货物列车脱轨全过程计算

为确保地震作用下货物列车在脱轨瞬间及时停车,建立地震作用下列车-轨道系统空间振动计算模型,并提出地震作用下列车脱轨全过程计算方法;以9~10级地震烈度下的强震为研究对象,分别计算货物列车以不同车速在直线和曲线线路上的脱轨全过程,分析轮轨几何接触状态及其相对位置.结果表明:地震烈度及车速对转向架与钢轨横向相对位移影响明显,而对转向架摇头角影响较小;曲线轨道对转向架与钢轨横向相对位移、转向架摇头角影响均较大;转向架与钢轨横向相对位移及转向架摇头角最大值分别为155 mm和4.6°.这些数据可为列车脱轨检测装置的研发提供参考.     

高速机车车辆横向振动最大偏移量计算

应用随机振动理论，通过对轮对输入轨道谱和解动力学方程得到准高速车辆最大横向振动偏移量，与线路动力学试验结果基本一致．用同样的方法再计算２００～３５０ｋｍ／ｈ运行时的车体横向振动偏移量，即可作为制定高速机车车辆限界和建筑限界的基本依据之一．     

雨雪气象条件下桥隧连接段行车稳定性

为了缓解雨雪气象条件下桥隧连接段的交通安全运行问题,采用Carsim仿真分析软件,建立车辆-道路三维模型,通过侧向偏移量和横摆角速度2个评价指标,系统地模拟分析雨雪气象条件下C级标准车在桥隧连接段行驶的稳定性,定量分析行车速度、路面摩擦因数、圆曲线半径对桥隧连接段行车稳定性和车辆横向稳定性能的影响。研究结果表明:侧向偏移量与横摆角速度对行车稳定性的评价具有一致性,当侧向偏移量和横摆角速度指标的值越小、越稳定,车辆行驶越安全;车辆速度与行车稳定性呈负相关,路面摩擦因数和圆曲线半径与行车稳定性呈正相关,即降低车速、增大路面摩擦因数和圆曲线半径均可有效地减小车辆的侧向偏移量。在雨雪气象条件下桥隧连接段的特殊行车环境下,车辆设计速度由80降低至75 km/h,降低了6.25%;路面摩擦因数增大至0.21、圆曲线极限最小半径由250增至265 m,增大了6%;二者均可保证车辆不发生大幅度侧滑,并能提升车辆行驶的稳定性和安全性,可为山区高速公路设计规划和交通运营管理提供参考。     

提速货车作用下铁路钢板梁横向振动机理

针对我国铁路货车提速过程中发现的铁路上承钢桥梁桥横向振动严重超限现象,以随机人工蛇行波行为激励输入,通过大量的模拟计算,对40m上承钢板梁在货车（空车）作用下的横向振动特性进行了初步探讨,结果表明：当输入蛇行波长在8－9m范围内,列车行驶速度为55－70km．h^-1时,蛇行运动频率为2．10Hz左右,正好与梁的横向有载频率接近,这时桥梁横向振动出现较大的振幅,计算出的结果与现场测试结果接近。     

提速货车作用下铁路钢板梁横向振动机理

针对我国铁路货车提速过程中发现的铁路上承钢板梁桥横向振动严重超限现象,以随机人工蛇行波作为激励输入,通过大量的模拟计算,对40ｍ上承钢板梁在货车(空车)作用下的横向振动特性进行了初步探讨.结果表明:当输入蛇行波长在8～9ｍ范围内,列车行驶速度为55～70ｋｍ·ｈ-1时,蛇行运动频率为2.10Ｈｚ左右,正好与梁的横向有载频率接近,这时桥梁横向振动出现较大的振幅,计算出的结果与现场测试结果接近提速货车作用下铁路钢板梁横向振动机理@李建中@范立础     

集装箱专用平车气动性能分析与比较

基于三维、不可压、定常N-S方程和κ-ε双方程湍流模型,采用有限体积法对3种不同设计方案在运行时速为160 km/h的集装箱专用平车(以下简称平车)在有、无横风情况下的气动性能进行分析与比较,其中:方案一的平车无端墙,侧梁侧面平直;方案二和三的平车均加有端墙,且侧梁加高、侧面形状分别为钝形和弧形.研究结果表明:在无横风情况下,方案一中没有端墙,迎风面积较小,受到的气动阻力最小,方案二和三中平车有端墙,迎风面积较大,受到的气动阻力也较大;有横风情况下,方案三中平车侧梁较高,车体迎风面正压区较大,而背风侧产生较大的涡流区,在此区域内压力较小,故其横向力较大,方案一中平车侧梁没有加高,受到的横向力最小;方案一中平车倾覆力矩最小,稳定性最好.因此,在有、无横风情况下,方案一中平车的气动性能均比其他2种设计方案的平车的优.     

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…