西山特长隧道水平层石灰岩围岩爆破与支护技术研究

针对西山特长隧道水平层石灰岩地质极易造成隧道拱顶超欠挖现象,结合现场围岩情况以及工程经验,从爆破参数选择、爆破工序实施、支护方案等方面进行了改进优化,从而达到水平层石灰岩地质条件下良好的爆破支护效果。     

基于响应面法的双前桥转向机构参数优化

针对某重型双前桥转向汽车轮胎磨损严重的问题,运用Adams/View建立了该型汽车双前桥转向机构的运动学模型,对其进行了运动学及转向性能仿真分析。针对第二桥车轮实际转角与理想转角之间差异较大的问题,采用灵敏度分析的方法,找出对转角差异影响较大的因子,在Adams/Insight中,使用响应面分析方法,对双前桥转向机构的参数进行了优化。对比优化前后的转角差异可知,实际转角与理想转角之间的差异得到了有效控制,从而降低了轮胎的磨损。     

以“校企共同体”合作模式培养国际化技能型人才的研究与实践——以中新（南通）国际海事培训中心为例

＂校企共同体＂合作模式把学校和企业两种不同的教育环境和资源有机结合起来,是一种有利于培养适应社会发展的新型人才培养模式。文章以中新（南通）国际海事培训中心为例,探讨了＂校企共同体＂合作模式对于培养国际化技能人才的优势及启示,具有一定的指导意义。     

Automatic identification of cracks from borehole image under complicated geological conditions

Identifying cracks from the spread image of a borehole wall is one of the most common usages of borehole imaging method. The manual identification of cracks is time-consuming and can be easily influenced by objective judgment. In this study, firstly, the image translation from RGB color model to HSV color model is done to highlight the structural plane region, which is closer to the color recognition of human sight; secondly, the Saturation component is filtered for further processing and a twice segmentation method is proposed to improve the accuracy of automatic identification. The primary segmentation is based on the statistics of saturation over a longer borehole section and can give a rough estimation of a crack. Then, the pixels are shifted in the reverse direction to the sine curve estimated and make the centerline of the crack flat. Based on the shifted image, the secondary segmentation is done with a small rectangle region that takes the baseline of the roughly estimated crack as its centerline. The result of the secondary segmentation can give a correction to the first estimation. Through verifying this method with actual borehole image data, the result has shown that this method can identify cracks automatically under very complicated geological conditions.     

Serial cost allocation in the cooperative purchasing organization

Under the seller＇s quantity discount, buyers self-organize or rely on a third party to aggregate their purchasing quantities to obtain lower prices. Because of the unequal member contributions in the cooperative purchasing organization, the buyers＇ strategy is different, the members often fluctuate, and the organizations do not sustain themselves. An effective mechanism is necessary to improve the performance of purchasing groups. We study the various forms of cost allocation mechanism in practice. Different allocation rules may have influence on the buyers＇ behavior （i.e., purchasing quantities, whether joining the organization or not）. We analyze the serial cost allocation and equilibrium purchasing quantity based on a Nash equilibrium, and the results show that each buyer is worse off when not participating in the existence buying organization of the other buyers. We further find that the serial mechanism just confirms the most efficient Nash equilibrium： reasonable cost allocation rule is necessary for the subjects to identify their optimal strategy.     

隧道动力深浅埋界限及其影响因素研究

通过有限元模拟计算了不同围岩条件、洞跨及地震烈度下的隧道地震反应特性,研究了隧道动力深浅埋划分界限及其影响因素。结果表明:隧道结构受力随着隧道埋深的增加呈现先增后减的变化规律,可见拐点即为深浅埋界限;围岩条件越好,隧道的动力深浅埋界限越深,隧道在Ⅲ级、Ⅳ级及Ⅴ级围岩条件下的动力深浅埋界限分别为100,80,60 m左右;隧道动力深浅埋界限深度随着隧道跨度的增加而减小,但其受影响程度较小,隧道在跨径为6,10,20 m的情况下的动力深浅埋界限分别为100,100,80 m左右;隧道动力深浅埋界限不受地震烈度的影响。     

新时期高校法治教育的困境与出路

高校法治教育不同于法律制度教育,其本质是法律信仰教育。鉴于当前高校法治教育在教育模式、教育理念和教育内容上无法满足大学生成长成才需求的现实困境,高校办学者应在明确法治教育独立地位的同时,转变教育理念,全面整合政府、高校和社会三方优质的法治教育资源,以大学生法治精神塑造为目标,构建"三位一体"的高校法治教育的新模式。     

直线型公交停靠站通行能力计算方法

为了提高公交停靠站通行能力计算方法的精确性,针对目前城市的公交运行现状,使用时空分布图分析了公交车在直线式停靠站的服务过程,在此基础上,综合考虑停靠站排队概率和停靠时间分布,推导了公交停靠站通行能力计算模型.对杭州市公交车停靠时间的分布函数进行了拟合,对数正态分布的拟合程度最优, 2个交通时段的K-S检验值分别为0.083 9和0.050 6.用MATLAB编程得到不同分布参数下的通行能力结果表明:随着停靠时间对数平均值μ的增加,不同泊位数停靠站的通行能力减少了44.4%~47.3%;通过VISSIM仿真得到了停靠站的通行能力,模型计算值与仿真结果的平均误差为6.5%.      

驻点热流测量试验技术研究

为了提高超声速脉冲风洞中球头驻点热流测量精度,对1 mm小型化同轴热电偶研制及薄膜热流传感器的耐冲刷性能进行研究.应用热传导反问题的计算分析方法,建立了分别针对薄膜热流传感器和同轴热电偶的数据处理方法.在2 m激波风洞上利用研制的5种不同类型及尺寸的传感器进行了球头驻点热流测量试验,将试验结果与F-R公式计算结果进行比较,并分析了传感器外形尺寸、热壁、传感器敏感元件、同轴热电偶膜厚等对试验结果的影响.结果表明:研制的小型化同轴热电偶响应时间满足测试要求;薄铂膜热流传感器重复性误差在8%以内.