The Effect of Adapter Crown Wear on Rated Fatigue Life of a Railroad Tapered Roller Bearing

A model is developed to describe the effects of adapter crown wear on the misalignment of a railroad tapered-roller bearing. Wear of the crowned surface results in a flat on top of the adapter. This flat, in contact with the wear plate, is shown to have the capacity to transmit a moment between the bearing and the side-frame of the truck. The magnitude of the moment transmitted is dependent on the length of the flat. These analytical results are coupled with model results from a bearing manufacturer, which give the relationship between bearing misalignment, and thus transmitted moment, and reduction in fatigue life of the bearing. The analysis indicates that a slightly worn adapter has no appreciable effect on the rated fatigue life of the bearing, but once a threshold level in adapter crown wear is reached, the bearing fatigue life will begin to decrease. Large amounts of adapter crown wear will result in significant bearing misalignment and a corresponding reduction in the fatigue life of the bearing.     

基于声速法的冲击矿压危险性预测研究

为了研究冲击矿压危险性和声波速度之间的关系,建立了损伤和纵波波速之间的定量关系,并通过对红砂岩进行单轴压缩实验,验证其正确性。利用上述关系,提出了冲击矿压危险性预测的一种新方法,并对危险等级进行了划分,提出了相应的解决措施。当应力水平较低时,纵波波速缓慢上升,损伤量减少;随着载荷的增加,到达峰值的80%~90%水平时,会出现纵波波速急剧下降,损伤量快速增大的现象,预示着破坏即将来临。     

煤炭产量预测与对比分析研究

为了预测我国的煤炭产量,分别建立了一元线性回归预测模型和灰色理论GM（1,1）模型,并对预测结果进行了比较分析。结果表明,灰色理论GM（1,1）模型较一元线性回归预测模型预测精度更高,更符合我国煤炭产量的发展趋势。灰色理论GM（1,1）模型的煤炭产量预测结果表明,未来2 a我国煤炭产量呈稳定增长趋势,产量分别为34.83亿t和37.82亿t,增长比例分别为7.5%和8.5%。     

测量仪器校准间隔的模糊范数融合预测

校准间隔的预测是解决测量仪器不足校准和过剩校准的一种主要方法。现有校准间隔预测模型仅仅关注瞬时值,而随机因素的存在导致瞬时值难以精确预测。针对这一问题,在历史校准数据为小样本条件下,提出一种模糊范数融合模型,进行测量仪器校准间隔预测。首先,通过分析历史校准数据的特征和影响因素,建立了校准数据的数学描述模型。在此基础上,采用模糊范数融合模型,预测校准数据的区间。实验表明,模糊范数融合模型更能反映校准数据序列的变化趋势,克服了其它预测模型仅仅预测瞬时值的缺点,提高了预测的可靠性。     

独头巷道掘进过程中排烟时间预测

分析了炮烟在独头巷道中的运移情况,从质量守恒角度建立了炮烟抛掷区中的炮烟排出数学模型。对归来庄金矿-118 m穿脉巷道爆破作业的现场炮烟监测,监测点炮烟浓度先增加后减小,炮烟排出过程中符合指数衰减。从爆破、炸药、通风条件、巷道情况4个方面分析了影响排烟时间的因素,利用BP神经网络模型,将炸药量、炮眼数目、风筒到掘进面的距离、监测点到掘进面的距离、风筒风量、风流温度、巷道温度、巷道相对湿度等因素的10组实验数据作为输入量,排烟时间作为输出量,获得稳定的网络结构。再将5组输入量实验数据代入BP网络训练,预测的排烟时间与实测的排烟时间相对误差在7%以内,运用BP网络模型取得了较好的预测效果。准确预测排烟时间,可以合理安排掘进作业,避免炮烟中毒事件发生,对矿山安全高效生产有重要的意义。     

Research on parametric design method for energy efficiency of green building in architectural scheme phase

Based on a large number of researches and engineering practices both domestic and overseas, it is shown that the building parameters to be determined during scheme phase can exert a great effect on the building energy consumption. In this paper, through a combination of the popular design method of building parameterization at present and the design goal of energy saving during the scheme phase, the author carries out researches on the design methods and tool development which are applicable to parameterization of building energy saving in this stage. In connection with the characteristics of both modeling process of parameterization and energy saving design, and by means of steady calculation as well as simulation, this paper establishes an simplified model to calculate the overall energy consumption of air-conditioning, heating, lighting and equipments, and ultimately gives suggestions on design of scheme for energy saving by optimization with the genetic algorithm (GA). On the basis of the model, a software platform is developed by computer language QT and openGL interface and is oriented to the design users and sets up the MMI (human–computer interaction) software interface for parameterization of building energy saving, which achieves automatic modeling of parameterization and promotes research on practical design cases.     

神经网络预测爆炸密实引起的地表沉降

爆炸密实法用于地基处理已有很长的历史,用此方法处理时所引起的地表沉降是衡量其处理效果的一个重要指标,许多学者提出了引起地表沉降量的统计预测模型。本文尝试建立了预测爆炸密实引起地表沉降的神经网络模型,由于用来训练网络的原始样本太少,难以训练出一个具有高精度的预测模型,为此采用了遗传算法与神经网络相结合的方法,得到了一个只有小样本输入却能得到高精度输出的神经网络模型。对检验样本的预测结果表明,所建立的神经网络模型具有很强的预测能力,其预测精度比已有的统计预测模型高。     

基于LS-SVM的飞机部件故障率预测

支持向量机具有完备的统计学习理论基础和学习功能。它用核函数建立预测模型,再用已知数据为学习样本训练学习机,用检验样本进行验证、预测系统未来故障。最小二乘支持向量机(LS-SVM)采用最小二乘线性系统作为损失函数,函数估计精度高、收敛速度快。基于支持向量机的多层参数寻优、等维信息一步预测和不等维信息多步预测,可用于飞机状态评估、故障诊断和参数预测以及故障率分析。     

时尚色彩--流行色初探

对流行色的基本认识与内涵进行了初步的分析与研究,尤其对流行色的生成原因、发展进一步深入调查,对流行色的预测与表达明确阐述了个人观点。说明了人们从生理和心理的角度对色彩的需求,从而达到了对流行色的应用与潜在商机。     

基于神经网络包装缓冲特性预测模型的研究

文中描述了冲击缓冲特性的预测模型,研究了不同的试验方案,其预测模型结果与实际值最大相对误差的变化规律,找出了能满足工程设计要求的最少试验方案.通过实例验证了该预测模型,其预测模型的结果对工程设计是十分便利.