流体参数对埋地管道破坏的影响分析

在考虑流固耦合和断层活动作用的情况下,应用ADINA中流固耦合分析求解器ADINA-FSI,建立了埋地管道破坏分析的有限元模型,介绍了固体模型和流体模型的建模过程以及流固耦合计算过程、断层位移荷载加载和约束的实现以及模型参数选择等。依据计算结果,分析了管内介质及流速等参数对管道破坏的影响。管道内输送的介质密度和流速越大,管道越易破坏,故在埋地管道设计中应充分考虑管内介质的密度与流速。针对计算结果,提出了几点认识和建议。     

覆冰输电塔-线体系风致动力响应分析

依据流体诱发振动原理,结合已有覆冰计算模型,考虑降雨的分类,模拟了输电塔-线体系不同高度导线的覆冰和风荷载。以东北地区某输电塔为例,对覆冰输电塔-线体系在稳定风速激励下的动力响应进行分析,并与不考虑塔线耦联的导线舞动分析结果及覆冰塔线拟静力的分析结果进行对比,对塔位移、输电线位移、钢材应力进行了分析。研究结果表明:塔-线耦联体系对覆冰导线风振有很大影响,覆冰输电塔抗风设计安全度需要进一步提高。     

拟合水工设计反应谱的人工地震波的生成与Huang变换校正

根据非平稳输入下建立的功率谱与均值反应谱之间的关系,合成基于水工设计反应谱的人工地震波,并对其幅值进行修正,降低了高频区误差作用;为了解决加速度时程积分后的速度、位移时程的零线漂移现象,利用Huang变换得到加速度时程的固有模态函数,由Huang变换方法得到的最低频率固有模态函数分量通常情况下代表原始信号的趋势或均值,对去掉均值后的加速度时程进行积分得到的速度、位移时程不存在零线漂移问题。     

延边地区水稻稳产高产施肥体系的探讨

采用二次饱和D-最优设计,建立了有机肥、氮肥、磷肥和钾肥配合施用对水稻产量影响的数学模型.研究表明有机肥施用量的过多或过少均使水稻产量下降,化肥的施用也有相似的影响;有机肥与氮肥、磷肥、钾肥只有施用量在适宜的范围内,交互作用较大,产量最高.提出了延边地区水稻获得稳产、高产的施肥体系.     

河流水生态环境质量评价方法研究与应用进展

河流生态质量的监测和评价是从河流生态系统健康状况的角度对河流质量进行的评价。河流生态健康的评价已经向多要素多指标综合、多种评价方法(预测模型法、生物完整性指数、多要素综合评价)、流域尺度方向发展。该文重点介绍了国外评价体系产生的背景和研究基础,分析了广泛应用的几类评价方法的特点、在不同国家和流域的应用情况以及各方法的应用前景,分析了国内开展河流生态质量评价研究的发展过程、阶段性研究进展和应用案例,并根据目前研究基础评述了我国评价体系现存问题及应用前景,为河流生态质量评价体系的建立及发展方向提供建议和参考。     

Technological innovation paths toward green industry in China

With the environmental carrying capacity reaching its limits and the decreasing margin benefits of traditional production factors, the green transformation and green development through technological innovations has been a major direction for the future development of Chinese industries. However, the characteristics and heterogeneities of various types of industries call for different approaches regarding technological innovations. How to choose the most effective mode of technological innovation according to the characteristics of a certain industry has been a key issue. This paper measures the green total factor productivity of 32 industrial trades using the Slacks Based Measure(SBM)-DDF method. The effects of three innovation modes in the green transformation of industrial industry, including the independent innovation(Ⅱ), the technology introduction(TI), and the government support(GS), are empirically analyzed based on industry heterogeneity. Results indicate that the green total factor productivities of different industries show significant differences if taking into account the energy input and the undesirable output of pollutant emissions. The green total factor productivities of traditional high input,high pollution, and high energy consumption industrial trades were significantly lower than those with obvious green features. The year of 2009 is a leap year for the industrial green transformation in China. For resource-intensive industries, the II and the GS are the important ways to achieve green transformation. For labor-intensive industries, the TI is the best path to achieve green transformation, while for technology-intensive industries, the II is the primary driving force for the promotion of green developments. In addition, the innovation-compensating effect of the current Chinese environmental regulations to the resource-intensive industries has been revealed. Improving the overall scale and the industrial concentration of the industries is also beneficial for the green transformation of the industries.     

基于情感思维的安全管理模式研究

为促进安全管理,提高效率与效果,对基于情感思维的安全管理进行研究,将情感思维融于安全管理,基于情感思维的定义、内涵及功能,具体分析安全管理中情感思维的功能及其功能综合作用,建立安全管理中情感思维功能作用理论模型;根据该理论模型分析情感思维驱动力及强化作用及其对安全目标实现的影响;建立基于情感思维的安全管理设计模式,最后提出优化安全管理的措施与方法,以促进安全管理的实施。研究表明:基于情感思维的安全管理研究,能较好地体现安全管理人本原理,发挥情感的能动作用,将理性融入其中与情感进行平衡,实现安全管理的优化。     

Structural equation model analysis for the evaluation of overall driving performance: A driving simulator study focusing on driver distraction

Objective: The present research relies on 2 main objectives. The first is to investigate whether latent model analysis through a structural equation model can be implemented on driving simulator data in order to define an unobserved driving performance variable. Subsequently, the second objective is to investigate and quantify the effect of several risk factors including distraction sources, driver characteristics, and road and traffic environment on the overall driving performance and not in independent driving performance measures.

Methods: For the scope of the present research, 95 participants from all age groups were asked to drive under different types of distraction (conversation with passenger, cell phone use) in urban and rural road environments with low and high traffic volume in a driving simulator experiment. Then, in the framework of the statistical analysis, a correlation table is presented investigating any of a broad class of statistical relationships between driving simulator measures and a structural equation model is developed in which overall driving performance is estimated as a latent variable based on several individual driving simulator measures.

Results: Results confirm the suitability of the structural equation model and indicate that the selection of the specific performance measures that define overall performance should be guided by a rule of representativeness between the selected variables. Moreover, results indicate that conversation with the passenger was not found to have a statistically significant effect, indicating that drivers do not change their performance while conversing with a passenger compared to undistracted driving. On the other hand, results support the hypothesis that cell phone use has a negative effect on driving performance. Furthermore, regarding driver characteristics, age, gender, and experience all have a significant effect on driving performance, indicating that driver-related characteristics play the most crucial role in overall driving performance.

Conclusions: The findings of this study allow a new approach to the investigation of driving behavior in driving simulator experiments and in general. By the successful implementation of the structural equation model, driving behavior can be assessed in terms of overall performance and not through individual performance measures, which allows an important scientific step forward from piecemeal analyses to a sound combined analysis of the interrelationship between several risk factors and overall driving performance.     

Are older drivers’ driving patterns during an on-road driving task representative of their real-world driving patterns?

Abstract

Objective: The current study investigated whether older drivers’ driving patterns during a customized on-road driving task were representative of their real-world driving patterns.

Methods: Two hundred and eight participants (male: 68.80%; mean age?=?81.52 years, SD?=?3.37 years, range?=?76.00–96.00 years) completed a customized on-road driving task that commenced from their home and was conducted in their own vehicle. Participants’ real-world driving patterns for the preceding 4-month period were also collected via an in-car recording device (ICRD) that was installed in each participant’s vehicle.

Results: During the 4-month period prior to completing the on-road driving task, participants’ median real-world driving trip distance was 2.66?km (interquartile range [IQR]?=?1.14–5.79?km) and their median on-road driving task trip distance was 4.41?km (IQR?=?2.83–6.35?km). Most participants’ on-road driving task trip distances were classified as representative of their real-world driving trip distances (95.2%, n?=?198).

Conclusions: These findings suggest that most older drivers were able to devise a driving route that was representative of their real-world driving trip distance. Future research will examine whether additional aspects of the on-road driving task (e.g., average speed, proportion of trips in different speed zones) are representative of participants’ real-world driving patterns.     

循环载荷下煤裂隙演化试验研究

为了研究循环载荷下的煤体裂隙演化特征,在不同应力水平和不同频率条件下分别进行煤样破坏力学及声发射试验。结果表明:应力-应变曲线呈疏-密-疏的变化特征,对应的振铃数柱状图呈U型;上限应力点的应变值、累积能量、撞击计数均随循环次数增加而上升,曲线呈倒S型;煤裂隙演化经历了原始裂隙闭合、新生裂隙稳定发育和裂纹贯穿破坏等3个不同阶段;循环载荷的应力水平和加载频率对煤体疲劳寿命的影响具有差异性,对煤体裂隙演化和破坏模式均有明显影响。