桥式起重机运行机构中自激振动的研究

研究了桥式起重机在迅速启、制动工况下主动车轮在轨道上打滑时运行机构中产生的摩擦自激振动，讨论了车轮、轨道之间摩擦特性曲线问题，利用求解非线性振动的方法计算了摩擦自激扭振的振幅、频率、时间及动载荷值．对两台桥式起重机大车运行机构的动载荷进行了现场实测，测试结果与计算基本相符，说明有关的计算公式具有比较好的实用性．     

桥式起重机运行机构中自激振动的研究

研究了桥式起重机在迅速启、制动工况下主动车轮在轨道上打滑时运行机构中产生的摩擦自激振动，讨论了车轮、轨道之间摩擦特性曲线问题，利用求解非线性振动的方法计算了摩擦自激扭振的振幅、频率、时间及动载荷值，对两台桥式起重机大车运行机构的动载荷进行了现场实测，测试结果与计算基本相符，说明腾的计算公式具有比较好的实用性。     

桥式起重机运动模拟

在桥式起重机是应用最为广泛的起重机械，文章综合应用现代设计手段和方法，在桥架、起升机构、小车运行机构和大车运行机构的基础上，建立三维运动分析的数学模型，从而对整机和各部件的运动速度、加速度以及因运动引起的载荷进行分析，模拟各种运动规律和运动轨迹，从而实现起重机运行情况的模拟，为起重机的设计提供可靠的参考依据。     

基于ANSYS的恒幅载荷下桥式起重机疲劳寿命模拟

针对评估桥式起重机金属结构疲劳寿命的问题,以桥式起重机受力分析为基础,借助ANSYS软件的相互作用积分法,结合恒幅载荷下裂纹扩展寿命的理论,对箱型梁腹板跨中部位的腹板——下翼缘板处的裂纹进行分析,拟合出应力循环次数与裂纹尺寸的关系,得出恒幅载荷下桥式起重机的疲劳裂纹扩展寿命。同时,归纳桥式起重机疲劳寿命计算的影响因素及其试验推荐值。结果表明,循环次数与裂纹尺寸之间的关系符合疲劳裂纹扩展的客观规律。     

桥式起重机大车自适应同步协调纠偏控制

针对桥式起重机大车行走过程易偏离正常轨道而造成平稳性和安全性下降的问题,提出一种大车同步协调纠偏控制方法。基于桥式起重机大车行走过程的受力分析,建立其纠偏动力学模型,提出基于"误差优化"学习算法的神经网络自适应控制策略,对桥式起重机大车的两侧速度进行协调控制,对速度差、位移差和偏转角进行快速在线调整,从而纠正大车行走偏差。研究结果表明:所提纠偏控制策略具有良好的纠偏控制效果,起重机大车可实时自调整,达到提高桥式起重机运行平稳性和安全性的目的。     

桥式起重机运行数据快速处理方法

提出一种利用起重机运行数据快速获取其应力时间历程数据的方法。通过已有的起重机运行数据,利用结构力学推导出的结构内力计算公式编制成计算机程序,对其进行快速处理,以获取桥式起重机应力时间历程数据。将公式计算结果与ANSYS分析结果对比,验证软件的可行性。该方法很好的解决了桥式起重机工况载荷数据缺乏的问题。     

浅谈桥式起重机啃轨现象分析及改进方法

啃轨是双梁桥式起重机故障的一主要形式，本文论述桥式起重机大车运行中出现的啃轨现象，分析其产生原因，并针对性地提出解决措施，且应用于生产实践中，取得较好的效果。     

桥式起重机运行机构反接制动时的动载荷研究

分析了桥式起重机反接制动过程中，车轮打滑和产生自激振动的原因，通过实验测得了动态扭矩的波形，确定了打滑的条件，推导了动载荷的计算公式，计算结果与实测值基本相符．对减缓机构动载荷提出了具体措施，对改善桥式起重机，特别是大型桥式起重机的工作性能有重要意义．     

主梁结构维护及起重机操作运行的安全措施

本文就桥式起重机的的疲劳累积损伤规律和疲劳寿命进行研究,在分析桥式起重机的疲劳破坏特性基础上,利用修正Miner法则计算的两侧主架焊缝的疲劳寿命,最后就得到结果提出主梁结构维护及保证其安全运行的对策措施。     

工程机械轮胎的可靠性电算分析

本文应用3σ上下限图法对工程机械轮胎进行了可靠性分析,定量计算了轮胎在不同寿命下的可靠度值。并在轮胎强度与载荷均服从正态分布的前提下,编制了进行可靠度置信限计算的通用程序,计算分析了轮胎可靠度的置信水平。     

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。     

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.