考虑气固耦合填埋场沉降数学模型

为研究城市生活垃圾填埋场孔隙气压对沉降的影响程度，把填埋场简化为非稳定单向气体渗流场，采用Gibson和Lo一维压缩模型及U．S．EPA Landgem产气方程，结合达西定律、气体状态方程、有效应力原理和多孔介质流体动力学理论，建立了考虑气固耦合的填埋场沉降计算模型。填埋场的沉降按封场前和封场后2个阶段分别计算，封场前填埋场接受垃圾，堆填压力增加，而封场后的堆填压力保持不变。运用差分法求解的结果表明，填埋场垃圾体内孔隙气压与深度、时间和透气率等因素有关。封场前，气压随深度和时间的增加而增加：封场后，气压随时间逐渐消散。高透气率的填埋场有较高的气体消散速率。封场前气压的增加减小了填埋场沉降速率，从而导致填埋场的容量减少。提出在填埋场沉降计算和边坡稳定分析时考虑气压影响的必要性。     

VSM型全电熔窑电极布置及功率、温度场形态的数值模拟

在全电熔玻璃窑的设计和运行中,电极布置与功率场的形态以及相应温度场的形态密切相关.本文利用有限元方法建立了VSM型玻璃电熔窑简化数值模型,通过数值模拟得到窑炉功率分布和温度分布形态特征,从功率场和温度场的形态中可以判断出玻璃液的热源和对流源、熔制工艺实现条件、高温区域对于耐火材料侵蚀影响,进而优化电极布置和窑体几何形态.     

电场对竖直微槽润湿及毛细流动特性影响

竖直微槽群毛细结构广泛应用在重力热管、蒸发器等散热设备内,但受重力等因素影响易达到毛细极限。引入电场的主动强化方式来提高竖直微槽的毛细极限,并通过实验和建立数学模型研究电场对竖直微槽内液体润湿及毛细流动特性的影响。结果表明,电场可以提高竖直微槽内液体润湿高度,当电场为5.0 kV时与无电场时相比,润湿高度强化比可达到30.0%。同时,电场作用下流体在微槽道内的毛细润湿流动呈分段效应：润湿流动初期,润湿高度与时间的1/2次方呈线性关系,即h-t^1/2,润湿速率与润湿高度的倒数呈线性关系,即v-1/h;润湿流动中后期,润湿高度与时间的1/3次方呈线性关系,即h-t^1/3,润湿速率与润湿高度平方的倒数呈线性关系,即v-1/h²,且润湿速率随时间呈下降趋势。     

On the association between poly(vinyl alcohol) and sodium dodecyl sulfate and its effect on liquid–liquid interfacial tension: A mathematical model

Association between poly(vinyl alcohol-co-vinyl acetate) copolymer (PVA) and sodium dodecyl sulfate (SDS) was studied experimentally and theoretically. It was found that, for the ethyl acetate-aqueous phase interface in which PVA was previously adsorbed, the interfacial tension (γ) increases abruptly to a maximum and then exhibits a relatively mild decay with the addition of SDS to the aqueous phase. The theoretical results indicate that vinyl acetate (VAc) segments determine γ. However, for relatively low concentrations of SDS (C_SDS), this latter plays a major role because through its association with the VAc segments it modulates the extent to which PVA is adsorbed at the interface, indirectly determining the value of γ. As C_SDS approaches to the CMC value for SDS, its influence on γ decreases because SDS tends to self-assembly rather than associates with VAc. These model predictions are consistent with experimental findings reported in the literature.     

Statistical Determination of Ignition Frequency of Structural Fires in Different Premises in Finland

Ignition frequencies and ignition frequencies per floor area were determined for different building categories in Finland as total groups and as a function of the floor area of the building. These frequencies are needed as input for risk analysis using performance based fire safety design. It was found that differences between building categories or location within country were so small that a universal curve for the whole country could be determined. For ignition frequency per floor area for small buildings a strong dependence on size is observed, but it remains approximately constant for larger buildings. Additionally periodical variations of ignition frequency of buildings by month and week of year, day of week, and time of day were determined. Historical review of the development of ignition frequency models was made. Some evaluation on the generality of the results was made based on the theoretical models.     

工程量清单条件下修订企业定额中的统计工作

实行工程量清单计价要求施工企业自主报价，企业定额的重要性日益突出，建立和完善企业定额必须要搜集和积累大量的信息资料，并对这些信息资料进行分析和归集，这必须要通过一定的统计工作来实现，本文通过3个层次来论述制定和完善企业定额中的统计工作。     

磁阻式无刷双馈电机的转子结构及其性能分析

把磁阻式结构与绕线式转子结构相结合,提出一种具有磁阻式无刷双馈电机的转子结构。该转子结构既保持了绕线式转子绕线接线方式的灵活性,又发挥了磁阻式转子对磁通的导向作用,改善了电机的磁场调制效果,可以很好地实现转子与定子两套绕组耦合能力实现最大化。对磁阻式转子结构的无刷双馈电机的设计原理和方法进行了详细分析,以一台30k W样机为例说明了磁阻式无刷双馈电机的功率分配曲线、气隙磁通密度曲线和电机效率,并与磁障结构的磁阻式、加入笼条的磁阻式转子无刷双馈电机在同等条件下的电机输出功率作对比。最后对无刷双馈发电系统的动态特性进行样机实验,实验结果表明采用该方法设计的磁阻式无刷双馈电机具有优良的性能。     

计及样本容量合理性的风电功率预测考核算法

在风功率预测误差服从正态分布的基础上,首先,提出了在给定置信水平、最大允许误差下最小样本容量的计算方法,以及在给定误差范围、样本容量下估计值置信水平的计算方法。其次,针对典型显著性水平、误差范围进行分析,论证了当样本容量较小时,样本统计指标置信水平低,无法代表总体指标。最后,提出了计及样本容量合理性的日前风电功率预测准确率考核算法,实际算例表明,所提考核算法更科学合理,避免了不合理的考核罚款。     

2.25Cr1Mo0.25V钢高温变形微观组织的演变分析与数值模拟

在Gleeble-3500热模拟试验机上对2.25Cr1Mo0.25V钢进行等温压缩试验,得到变形温度在900~1200℃、应变速率在0.001~10 s-1、变形量为60%时的高温流动应力-应变曲线。结合金相实验,研究2.25Cr1Mo0.25V钢在不同变形条件下微观组织的演变规律,建立2.25Cr1Mo0.25V钢在高温塑性变形过程中的动态再结晶数学模型。将模型与有限元结合,对热压缩过程的组织演化进行数值模拟,模拟结果与试验结果的相对误差小于11%,验证了模型的正确性。     

神华上湾煤慢速和快速热解焦燃烧性能及其反应动力学

对神华600℃慢速焦和快速焦表面形貌和官能团进行分析的基础上,利用热重法研究了煤焦的燃烧反应性,采用修正随机孔模型（MRPM）模拟回归了神华煤焦的燃烧反应动力学。结果表明,神华慢速焦SHs的主要组成部分为密实状结构,快速焦SHf具有大量的气孔。对比SHf的红外光谱图,SHs含有较少的羟基-OH,羰基减少甚至消失,脂肪族-CH3和-CH伸缩振动减弱,有较高的芳环缩合度。燃烧特征参数表明,SHs较SHf的着火温度高,燃尽温度低,燃烧性能高。修正随机孔模型对两种焦的拟合度很高,拟合相关系数R2均为0.9997,均方根误差RMSE均为0.006。拟合SHs燃烧活化能E为60.01 KJ/mol,结构参数ψ为1,而SHf的E为44.88 KJ/mol,ψ为0.62。