遂渝线路基上板式无碴轨道结构设计研究

研究目的:本研究主要为了确定遂渝线无碴轨道综合试验段路基(刚性路基、土路基)上铺设板式无碴轨道的轨道结构参数。研究方法:利用有限元模型,路基按刚性路基、土路基、设与不设混凝土层、轨道板与底座伸缩缝是否对齐等多种工况进行轨道结构各层及基床表层的受力特性分析。研究结果:对于板式轨道没有必要在底座下设置混凝土层。土路基上轨道板与底座伸缩缝错开设置对轨道结构受力较为有利。研究结论:在刚性路基和土路基上,板式轨道可不设置支承层。土路基上设计板式轨道时应尽量减少底座伸缩缝的设置,同时应使轨道板与底座伸缩缝错开布置。刚性路基上设计板式轨道时可根据工程需要来确定轨道板与底座伸缩缝是否对齐。土路基上,在相同条件下,基床表层厚度由400 mm增加到700 mm,各层应力变化很小。     

Evaluating transfer velocity-wind speed relationship using a long-term series of direct eddy correlation CO2 flux measurements

Long-term observations of the marine atmospheric boundary layer were performed by an eddy correlation system, which was set-up on a platform in the Baltic Sea. In this experiment the three-dimensional wind vector and the turbulent fluxes of momentum, sensible and latent heat and CO₂ were measured for one and a half years. Simultaneously the CO₂ partial pressure p_CO2 in surface water was measured by a submersible autonomous moored instrument for CO₂ at the platform in 7-m depth. The high-resolution eddy correlation measurements of the atmospheric CO₂ flux F_CO2, together with the measurements of the CO₂ partial pressure differences between air and sea Δp_CO2 led to a long-term data set which provided the possibility to investigate the parameterization of the CO₂ transfer velocity k as a function of 10-m wind speed u in a statistical manner. From half-hour mean CO₂ fluxes and CO₂ partial pressure differences, k was calculated using k = F_CO2 / (K₀Δp_CO2), with K₀ the CO₂ solubility. The half-hour mean data points, used for the determination of the k–u parameterization, show large scatter. However, assuming a linear, quadratic dependency the analysis yields: k₆₆₀ = 0.365u² + 0.46u (k at 20 °C and salinity 35 psu) with a correlation coefficient of r² = 0.81. The large scatter indicates that the kinetics of the air–sea CO₂ transfer velocity is not only a function of the wind speed alone, but might also be controlled by other environmental parameters and mechanisms, such as sea state and surface coverage with surfactants.     

龙滩枢纽变动回水区航道设计参数研究

结合北盘江龙滩枢纽枢纽调度提出航道整治设计参数的确定方法,并对其水流特性进行分析研究,为类似工程提供参考.     

技术资产收益分成定价模型的参数分析

使用收益分成算法模型估算技术资产价值,其准确度取决于各参数的确定,这也是容易引起争论的问题。介绍了收益分成定价模型中收益分成率的计算思路,阐述了预期收益额的几种不同含义及较科学的确定方法,指出了贴现利率的计算方式,提出了不同的技术资产及其寿命周期的算法及应注意的问题。最后举例进行了分析。     

Suspension parameter estimation in the frequency domain using a matrix inversion approach

The dynamic lumped parameter models used to optimise the ride and handling of a vehicle require base values of the suspension parameters. These parameters are generally experimentally identified. The accuracy of identified parameters can depend on the measurement noise and the validity of the model used. The existing publications on suspension parameter identification are generally based on the time domain and use a limited degree of freedom. Further, the data used are either from a simulated ‘experiment’ or from a laboratory test on an idealised quarter or a half-car model. In this paper, a method is developed in the frequency domain which effectively accounts for the measurement noise. Additional dynamic constraining equations are incorporated and the proposed formulation results in a matrix inversion approach. The nonlinearities in damping are estimated, however, using a time-domain approach. Full-scale 4-post rig test data of a vehicle are used. The variations in the results are discussed using the modal resonant behaviour. Further, a method is implemented to show how the results can be improved when the matrix inverted is ill-conditioned. The case study shows a good agreement between the estimates based on the proposed frequency-domain approach and measurable physical parameters.     

SS_(7C)客运电力机车性能综述

介绍了 Ｓ Ｓ７ Ｃ型客运电力机车的主要设计思路、特性、技术参数等，对其牵引客运列车的性能进行了简要的分析。     

广义相关时延估计算法在汽车去噪系统中的应用

针对汽车环境中麦克风阵列语音去噪系统的应用,对广义相关时延估计方法进行了仿真,并与基于高阶累积量的时延估计方法作了比较分析.给出了两种方法在不同信号模型中的仿真结果,结果表明:广义相关法时延估计更适用于汽车去噪系统.     

新海鳄轮挖吹硬塑性亚粘土施工分析

通过对新海鳄轮绞吸挖泥船在连云港港庙岭三期突堤码头疏浚工程挖掘与泵送硬塑性亚粘土施工情况进行分析,进一步了解了泥泵泵送硬塑性亚粘土的流态和参数变化,对绞吸船在挖吹粘性土领域的研究具有借鉴意义。     

潮位相关分析中的最小二乘法研究

在潮位相关分析中,若2个相关变量均存在误差且几率相仿时,应用传统最小二乘法可能获得不甚合理的线性相关结果,所拟合的直线不具备可逆性。文中从直线拟合的数学定义出发,探索潮位相关分析中的最小二乘法问题。初步应用研究表明,文中提出的方法可以有效地解决传统最小二乘法在线性相关分析中出现的不合理现象,使分析结果与实际符合良好,回归方程具有良好的可逆性。     

多个波高仪实现两点法分离合成波浪

利用多个波高仪解决了两点法间距取值局限性的问题,利用FFT实现了波浪三角级数展开式系数的快速运算。改进的两点法可以分离规则波和不规则波,本文首先分离叠加噪声的计算机模拟合成波浪,分离精度利用相关系数评价,然后测试无反射造波水槽中的现场合成波浪,经波谱分析,分离精度能够达到工程标准。