The Upper Ordovician-Lower Silurian Longmaxi Shale in the Upper Yangtze block represents one of the most important shale gas plays in China. The shale composition, porosity, organic thermal maturity, and methane sorpt...The Upper Ordovician-Lower Silurian Longmaxi Shale in the Upper Yangtze block represents one of the most important shale gas plays in China. The shale composition, porosity, organic thermal maturity, and methane sorption were investigated at the Qilongcun section in the Dingshan area, southeastern Sichuan Basin. The results show that the Upper Ordovician-Lower Silurian Longmaxi Shale contains: (1) sapropelic I organic matter; (2) a 40-m thick bedded sequence where total organic carbon (TOC) content is 〉 2%; (3) a 30-m thick layer at the base of the Longmaxi Shale with a brittle mineral content higher than 50%; and (4) a mean methane adsorption capacity of 1.80 cm3/g (7 MPa pressure). A positive correlation between TOC and sorbed gas indicates that organic matter content exerts an important control on methane storage capacity. Based on the analysis of the shale reservoir characteristics, the lower member of the Longmaxi Shale can thus be considered a favorable stratum for shale gas exploration and exploitation. It has similar reservoir characteristics with the Longmaxi Shale in the Jiaoshiba area tested with a high-yield industrial gas flow. However, based on tectonic analysis, differences in the level of industrial gas flow between the low-yield study area and the high-yield Jiaoshiba area may result from different tectonic preservation conditions. Evidence from these studies indicates the shale gas potential of the Longmaxi Shale is constrained by the reservoir and preservation conditions.展开更多
互通式立交承担着不同方向交通流的流向转换功能,是道路交通网络的重要节点。目前高密度立交在城市道路网络中已愈发常见,高密度立交之间的间距比普通立交更小,车辆交织更为密集,驾驶人需要在更短的时间内进行分合流驾驶操作。为探究立...互通式立交承担着不同方向交通流的流向转换功能,是道路交通网络的重要节点。目前高密度立交在城市道路网络中已愈发常见,高密度立交之间的间距比普通立交更小,车辆交织更为密集,驾驶人需要在更短的时间内进行分合流驾驶操作。为探究立交间距对驾驶人精神负荷的影响与高密度立交出入口区段的驾驶人精神负荷统计特性,在重庆市内环快速路上选择了1段包含4座连续立交的路段作为实验对象,其中3座立交为高密度立交。通过车载仪器采集47名驾驶人在实车实验过程中的心电数据,对在高密度立交出入口区段与普通间距立交出入口区段的驾驶人心率变异性时域和频域指标进行差异性分析,得到了驾驶人在高密度立交与普通间距立交出入口区段的精神负荷分布特征。研究结果表明:驾驶人在经过普通间距立交出入口区段和高密度立交出入口区段时的心率变异性时域指标不存在显著性差异,频域指标心率变异性的低、高频功率的比值(ratio of low-frequency to high-frequency,LF/HF)存在显著性差异,频域指标LF/HF可作为评价驾驶人精神负荷在立交出入口区段的主要指标;驾驶人在经过高密度立交入口区段时,频域指标LF/HF比经过普通间距立交入口区段时显著增加,立交间距不足会增加驾驶人在立交入口区段的精神负荷;驾驶人在经过普通间距立交出口区段时的心率变异性频域指标LF/HF比经过高密度立交出口区段时显著增加,即驾驶人通过普通间距立交出口区段的精神负荷更大;对于高密度立交群,驾驶人在入口区段的精神负荷水平要略高于出口区段。展开更多
要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率...要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率指标变化情况。本次试验基于主成分分析法选择心率变异率指标RMSSD(root mean square of successive differences)、LFnorm(low frequency norm)、HFnorm(high frequency norm)、LF(low frequency)/HF(high frequency)以及心率突变率指标HRMR(heat ratemutation rate)作为驾驶人精神负荷的评价指标,记为主成分F 1和主成分F 2,并建立评价模型。结果表明:驾驶人在小净距立交出入口区段行驶时,立交主线车流量的大小会影响驾驶人的精神负荷;当驾驶人驶入立交主线时,三次模型对入口段车流量与主成分F 2的拟合效果最好,呈开口向上的三次曲线,曲线谷值点出现在2级流量水平处,模型显著;当驾驶人驶出立交主线时,一次线性模型对出口段车流量与主成分F 1的拟合效果最好,模型显著。展开更多
基金supported by Science and Technology Support Program of Sichuan Province(No.15ZC1390)National Natural Science Foundation of China(No.41102064)
文摘The Upper Ordovician-Lower Silurian Longmaxi Shale in the Upper Yangtze block represents one of the most important shale gas plays in China. The shale composition, porosity, organic thermal maturity, and methane sorption were investigated at the Qilongcun section in the Dingshan area, southeastern Sichuan Basin. The results show that the Upper Ordovician-Lower Silurian Longmaxi Shale contains: (1) sapropelic I organic matter; (2) a 40-m thick bedded sequence where total organic carbon (TOC) content is 〉 2%; (3) a 30-m thick layer at the base of the Longmaxi Shale with a brittle mineral content higher than 50%; and (4) a mean methane adsorption capacity of 1.80 cm3/g (7 MPa pressure). A positive correlation between TOC and sorbed gas indicates that organic matter content exerts an important control on methane storage capacity. Based on the analysis of the shale reservoir characteristics, the lower member of the Longmaxi Shale can thus be considered a favorable stratum for shale gas exploration and exploitation. It has similar reservoir characteristics with the Longmaxi Shale in the Jiaoshiba area tested with a high-yield industrial gas flow. However, based on tectonic analysis, differences in the level of industrial gas flow between the low-yield study area and the high-yield Jiaoshiba area may result from different tectonic preservation conditions. Evidence from these studies indicates the shale gas potential of the Longmaxi Shale is constrained by the reservoir and preservation conditions.
文摘互通式立交承担着不同方向交通流的流向转换功能,是道路交通网络的重要节点。目前高密度立交在城市道路网络中已愈发常见,高密度立交之间的间距比普通立交更小,车辆交织更为密集,驾驶人需要在更短的时间内进行分合流驾驶操作。为探究立交间距对驾驶人精神负荷的影响与高密度立交出入口区段的驾驶人精神负荷统计特性,在重庆市内环快速路上选择了1段包含4座连续立交的路段作为实验对象,其中3座立交为高密度立交。通过车载仪器采集47名驾驶人在实车实验过程中的心电数据,对在高密度立交出入口区段与普通间距立交出入口区段的驾驶人心率变异性时域和频域指标进行差异性分析,得到了驾驶人在高密度立交与普通间距立交出入口区段的精神负荷分布特征。研究结果表明:驾驶人在经过普通间距立交出入口区段和高密度立交出入口区段时的心率变异性时域指标不存在显著性差异,频域指标心率变异性的低、高频功率的比值(ratio of low-frequency to high-frequency,LF/HF)存在显著性差异,频域指标LF/HF可作为评价驾驶人精神负荷在立交出入口区段的主要指标;驾驶人在经过高密度立交入口区段时,频域指标LF/HF比经过普通间距立交入口区段时显著增加,立交间距不足会增加驾驶人在立交入口区段的精神负荷;驾驶人在经过普通间距立交出口区段时的心率变异性频域指标LF/HF比经过高密度立交出口区段时显著增加,即驾驶人通过普通间距立交出口区段的精神负荷更大;对于高密度立交群,驾驶人在入口区段的精神负荷水平要略高于出口区段。
文摘要为明确高密度互通立交行驶环境下,主线车流量对出入口区段驾驶人精神负荷间的影响,在重庆市内环快速路高密度互通立交群进行自然驾驶实车试验,使用Physiolab生理检测仪连续采集驾驶人在行驶过程中的心电数据,用于统计各驾驶人的心率指标变化情况。本次试验基于主成分分析法选择心率变异率指标RMSSD(root mean square of successive differences)、LFnorm(low frequency norm)、HFnorm(high frequency norm)、LF(low frequency)/HF(high frequency)以及心率突变率指标HRMR(heat ratemutation rate)作为驾驶人精神负荷的评价指标,记为主成分F 1和主成分F 2,并建立评价模型。结果表明:驾驶人在小净距立交出入口区段行驶时,立交主线车流量的大小会影响驾驶人的精神负荷;当驾驶人驶入立交主线时,三次模型对入口段车流量与主成分F 2的拟合效果最好,呈开口向上的三次曲线,曲线谷值点出现在2级流量水平处,模型显著;当驾驶人驶出立交主线时,一次线性模型对出口段车流量与主成分F 1的拟合效果最好,模型显著。