平衡悬架钢板弹簧模型的建立与仿真

为更好分析重型卡车平衡悬架钢板弹簧的性能,应用离散梁单元方法创建了某重型卡车平衡悬架钢板弹簧的多体动力学模型,解决了重型卡车平衡悬架钢板弹簧大变形、接触非线性以及干摩擦等问题。通过调整离散梁单元的各项参数,得出了与实际钢板弹簧的垂向刚度变化和迟滞特性一致的模型。研究结果表明采用离散梁单元法建立的平衡悬架钢板弹簧模型能更真实、可靠地反映钢板弹簧的特性,也为整车动力学模型的建立提供了既准确又方便的平衡悬架钢板弹簧模型。     

汽车钢板弹簧多体动力学建模及动特性仿真研究

汽车悬架系统常用的弹性元件钢板弹簧,既是弹性元件,又是传递纵向、侧向地面作用力的传力元件,进行动力学建模时存在一定难度。文章从多体系统动力学的角度出发,建立了钢板弹簧的多体动力学模型,并应用机械系统动力学仿真软件ADAMS对其动特性进行了计算机仿真,仿真分析的结果与试验数据基本吻合,说明该仿真是成功的     

轿车扭力梁后悬架的开发研究

对比了扭力梁与多连杆悬架的基本特性,介绍了多体系统动力学软件ADAMS的功用,构建了后扭力梁模型,对悬架侧向力特性、车轮反向跳动特性、侧倾中心高,以及不同侧倾中心高对整车转向特性的影响,进行了动力学分析,得出了关于扭力梁位置、模型前束变化、侧倾中心高与开口的关系以及方向盘转角超调量等关系到新产品设计的重要结论.     

非公路矿用宽体自卸车悬架系统仿真分析

非公路矿用宽体自卸车悬架系统对车辆的行驶性能及寿命有着重要影响.采用多体动力学理论,利用多体动力学软件Adams建立包括非线性前悬架系统、非线性后悬架系统、轮胎、路面在内的多体动力学模型;分析前、后悬架系统在D级搓板路行驶时的受力情况,得到前、后钢板弹簧的受力趋势.仿真结果可为车辆设计提供一定依据.     

麦弗逊悬架减震器侧向力优化

由于麦弗逊悬架减振器不可避免地承受侧向力作用,其性能的好坏往往取决于侧向力大小.建立了能够综合考虑螺旋弹簧几何形状、弹簧轴线偏置角度、弹簧座安装角度及不同载荷状态的ADAMS刚柔耦合动力学优化模型,通过建立弹簧柔性体文件,可在多体动力学软件中模拟弹簧座与弹簧之间的支撑力及支撑力矩,为优化减振器侧向力提供仿真手段,大大提...     

钢板弹簧建模模块Leafspring的研究及其应用

Leafspring是ADAMS中的一个专用模块,应用其可以快速建立钢板弹簧多体动力学模型。为更好应用Leafspring,总结了其主要特点,分析了其建模基本原理,说明了其建模步骤。应用Leafspring,在ADAMS/Car中建立了2片簧钢板弹簧多体动力学模型,通过对模型的必要修改,实现了钢板弹簧垂向刚度特性的仿真测试,通过与实际钢板弹簧刚度特性比较,验证了所建模型的有效性。     

基于遗传神经网络的车轮匹配整车逆动力学

为深入研究机械弹性车轮(MEW)的力学性能和整车稳定性的相互匹配关系,在Simulink中建立了整车非线性三自由度模型;利用基遗传算法对车轮模型参数进行辨识,并提取侧偏刚度与侧向力峰值作为车轮力学特性的评价指标;利用该模型进行了前后轴不同侧偏刚度和侧向力峰值组合的汽车前轮正弦输入模拟仿真,得到若干组汽车稳定性指标参数;利用遗传算法优化,建立了输入为汽车稳定性评价指标,输出为前后轮侧偏刚度和侧向力峰值组合的BP神经网络逆动力学模型.研究结果表明:遗传算法对车轮参数识别误差小于4%,用遗传神经网络算法(GANN)得到的测试结果最大误差为6.2%,平均误差为3.1%,所建立的遗传神经网络模型具有较高的车轮侧偏特性预测能力.     

救护用车涉稳构件性能优化

为提高福特全顺CLW5030XJHJ5救护车的行驶舒适度，建立整车多体动力学模型和路面模型进行仿真测试，对前悬架和后悬架进行优化。采用ADAMS软件对车辆悬架系统进行建模和计算，并对计算结果进行分析，得出行驶过程的舒适性指标。利用遗传算法对前悬架扭杆弹簧的直径、长度，以及后悬架钢板弹簧厚度进行多目标优化，得到优化方案。研究结论可为救护用车涉稳构件的优化提供理论参考。     

汽车质心侧偏角观测器试验验证

提出了一种综合运动学和动力学模型估算车辆质心侧偏角的方法。引入非线性因子表征车辆的非线性状态程度,在此基础上提出了一种简化的非线性轮胎侧向力计算方法,考虑轮胎侧偏刚度补偿,基于单轨模型建立Kalman滤波器实时估计出车辆质心侧偏角。搭建基于轮速传感器、侧向加速度和横摆角速度组合传感器、方向盘转角传感器、MicroAutoBox和GPS系统的试验验证系统,在高附着路面条件下进行蛇形操纵和双移线操纵试验。试验结果表明:所设计的估计算法能在一定程度上反映车辆的实际状态,实时性和估计精度能满足稳定性控制系统的要求。     

微型客车整车多体系统动力学的建模与仿真

国内某微型客车采用了若干体现当今微型车发展方向的结构特征。在ADAMS软件系统基础上，建立了该车整车多体系统动力学的仿真模型，验证了应用该模型模拟仿真整车操纵稳定性的准确性；通过方向盘转角阶跃输入、蛇行转向、直线制动和复杂道路等典型行驶工况性能仿真分析，从多个方面对整车的操纵稳定性进行了分析和评估。     

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.     

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.     

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.