大型航天器结构-控制-光学一体化建模与微振动响应快速计算方法

目的控制大型航天器一体化模型的计算成本。方法分别使用状态空间法和附加刚度法建立结构-控制-光学一体化模型,并求解微振动响应。使用稀疏矩阵LU分解法和迭代法求解线性方程来加速微振动响应的求解速度。结果对某大型航天器建立一体化模型,并求解微振动响应,总耗时10.35 s,其中使用迭代法计算2794个频率点耗时7.20s,使用稀疏LU分解法计算6个频率点耗时3.15s。结论数值算例证明了该方法的高效性,是适用于实际工程中大型航天器微振动预示的高效算法。     

平原区二维复杂河流水质模拟计算

研究了湘江航运大源渡枢纽工程对湘江衡阳市区段水质影响的二维的数值计算方法，研究河段具有河道弯曲、分汊、江心有洲的复杂特点，应用有限单元法与单元网络划分的有关理论，在河流速度场资料的情况下，建立了利用河道水下地形图进行河不质数值计算的方法，并计算出了研究河段水质的浓度场分布，应用所建立的方法，可以进行各种复杂地形条件和不同水位情况下平原区线水河流水质的数值计算。     

华北山区温度推算模式和应用

利用华北山区气象站观测的温度与其所在纬度、经度和高度，分山区建立宏观地面气温场方程。采用１：２０万地形图，以１０＇经、纬度为步长，判读其高度值，代入已建立好的方程中，经地形项订正，推算华北山区年、月平均温度、年较差和ΣＴ＇≥１０℃，其精度达极显著水平。计算结果使我们对华北山区热量资源有了新的认识，最后求算华北山区的主要水果最优品质种植上限高度。     

Carbonyls in the metropolitan area of Mexico City: calculation of the total photolytic rate constants Kp(s(-1)) and photolytic lifetime (tau) of ambient formaldehyde and acetaldehyde

A great number of studies on the ambient levels of formaldehyde and other carbonyls in the urban rural and maritime atmospheres have been published because of their chemical and toxicological characteristics, and adverse health effects. Due to their toxicological effects, it was considered necessary to measure these compounds at different sites in the metropolitan area of Mexico City, and to calculate the total rate of photolytic constants and the photolytic lifetime of formaldehyde and acetaldehyde. Four sites were chosen. Sampling was carried out at different seasons and atmospheric conditions. The results indicated that formaldehyde was the most abundant carbonyl, followed by acetone and acetaldehyde. Data sets obtained from the 4 sites were chosen to calculate the total rate of photolysis and the photolytic lifetime for formaldehyde and acetaldehyde. Maximum photolytic rate values were obtained at the maximum actinic fluxes, as was to be expected.     

Modeling Free-Surface Fluctuation Effects for Calculation of Turbulent Open-Channel Flows

A new method of introducing the free-surface effects in the calculation of turbulent open-channel flows using the amplitude of the free-surface fluctuation is proposed along with a modeling method of the equation for the free-surface fluctuation. It can be incorporated in two-equation models like k-or k-type models by introducing the damping factor to represent the interaction of the eddies with the fluctuating free-surface. Test calculations for fully developed flows and those over backward-facing step indicate good agreement with direct numerical simulation results as well as experimental results.     

黑色金属挤压力的智能化计算

以MATLAB应用软件作为开发平台介绍了黑色金属挤压力智能化计算软件的开发方法,设计的界面友好,操作简单,可实现冷挤压力的智能化计算以及工艺参数优化设计。软件计算的挤压力的大小与传统方法比较相对误差小于5%。     

立式金属油罐容积编表计算机自动查询与计算系统

介绍了立式金属油罐容积编表计算机自动查询与计算系统的设计思想，查询计算原理，功能及实现，程序的编制及调试，应用及测试等，该系统的建立旨在克服人工查询与计算方法的计算繁琐，费时，易出差错的缺点，达到了本质安全。     

A spectral power analysis of driving behavior changes during the transition from nondistraction to distraction

Objective: This article investigated and compared frequency domain and time domain characteristics of drivers' behaviors before and after the start of distracted driving.

Method: Data from an existing naturalistic driving study were used. Fast Fourier transform (FFT) was applied for the frequency domain analysis to explore drivers' behavior pattern changes between nondistracted (prestarting of visual–manual task) and distracted (poststarting of visual–manual task) driving periods. Average relative spectral power in a low frequency range (0–0.5 Hz) and the standard deviation in a 10-s time window of vehicle control variables (i.e., lane offset, yaw rate, and acceleration) were calculated and further compared. Sensitivity analyses were also applied to examine the reliability of the time and frequency domain analyses.

Results: Results of the mixed model analyses from the time and frequency domain analyses all showed significant degradation in lateral control performance after engaging in visual–manual tasks while driving. Results of the sensitivity analyses suggested that the frequency domain analysis was less sensitive to the frequency bandwidth, whereas the time domain analysis was more sensitive to the time intervals selected for variation calculations. Different time interval selections can result in significantly different standard deviation values, whereas average spectral power analysis on yaw rate in both low and high frequency bandwidths showed consistent results, that higher variation values were observed during distracted driving when compared to nondistracted driving.

Conclusions: This study suggests that driver state detection needs to consider the behavior changes during the prestarting periods, instead of only focusing on periods with physical presence of distraction, such as cell phone use. Lateral control measures can be a better indicator of distraction detection than longitudinal controls. In addition, frequency domain analyses proved to be a more robust and consistent method in assessing driving performance compared to time domain analyses.     

餐饮行业细颗粒物(PM2.5)排放测算方法:以上海市为例

以上海市餐饮企业为例,研究了餐饮企业PM_(2.5)排放特征以及排放测算方法.按照单位灶头、单位时间、单位就餐人次这3种计算基准,获得了不同类型餐饮企业PM_(2.5)的排放因子,并在此基础上结合2014年上海市餐饮企业活动水平测算了PM_(2.5)的排放清单.结果表明,餐饮企业排放PM_(2.5)的浓度范围0.1~1.8 mg·m~(-3),甚至超过国家饮食业标准中关于油烟1mg·m~(-3)的排放限值;PM_(2.5)中OC质量贡献超过50%,OC/EC比值的变化范围为58.8~752.3,平均值为128.4,可作为餐饮排放的示踪特征.企业规模是影响餐饮企业PM_(2.5)排放因子的重要因素.按照灶头活动、餐饮作业时间以及就餐人次这3种方法计算得出的餐饮企业PM_(2.5)排放因子均表明,大型、中型企业明显高于小型和微型企业(食堂、快餐).基于上述3种排放因子,计算2014年上海PM_(2.5)排放量相对一致,表明本研究获得基于3种活动水平的排放因子比较可靠,未来可应用于其他城市餐饮企业排放清单的核算.     

多承载索货运索道计算方法及张力不平衡效应分析

通过分析多承载索货运索道工作索的空间位置关系,在弹性悬链线计算方法的基础上,建立包括索道结构守恒方程和力平衡方程的非线性方程组,形成多承载索货运索道系统整体耦合计算方法。针对四承载索货运索道的典型设计工况,应用该方法完成承载索长度不一致情况下,货运索道的承载索张力变化分析。研究结果表明:多承载索货运索道承载索间的张力不平衡受索长偏差影响极大,而且不平衡效应与索长变化工况（索长偏差变化量、变化索的位置等）和载荷重量密切相关,多索索长不一致造成的张力不平衡使得承载索破断风险急剧增加。