Background: Cycling currently comprises only 1% of transport trips in the U.S. despite benefits for air pollution, traffic congestion, and improved public health. Methods: Building upon the Level of Traffic Stress (LT...Background: Cycling currently comprises only 1% of transport trips in the U.S. despite benefits for air pollution, traffic congestion, and improved public health. Methods: Building upon the Level of Traffic Stress (LTS) methodology, we assessed GPS trip data from utilitarian cyclists to understand route preferences and the level of low stress cycling connection between origins and destinations. GPS data were obtained from adult transport cyclists over multiple days. All bikeable road segments in the network were assigned an LTS score. The shortest paths between each origin and destination along bikeable roadways and along low stress (LTS 1 or 2) routes were calculated. Route trajectories were mapped to the LTS network, and the LTS and distances of observed, the shortest and low stress routes were compared. LTS maps and animations were developed to highlight where low stress connections were lacking. Results: There were 1038 unique cycling trips from 87 participants included in the analysis. An exclusively low stress route did not exist for 51% of trips. Low stress routes that were possible were, on average, 74% longer than the shortest possible path and 56% longer than the observed route. Observed routes were longer and lower stress than the shortest possible route. Conclusions: Results indicate that transport cyclists traveled beyond low stress residential areas and that low stress routes with acceptable detour distances were lacking. Cyclists appeared to weigh both route distance and quality and were willing to trade maximum directness for lower stress. GPS data provide additional information to support planning decisions to increase the impact of infrastructure investments on cycling mode share.展开更多
Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various ...Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways.展开更多
The influence of rainfall and thermal stress in accident occurrence for the period 1985 through 1994 in Hong Kong was investigated. The existence of seasonal variations and weekly cycle was also examined. Daity accide...The influence of rainfall and thermal stress in accident occurrence for the period 1985 through 1994 in Hong Kong was investigated. The existence of seasonal variations and weekly cycle was also examined. Daity accident and meteorological data were obtained from the Transport Department and the Hong Kong Observatory respectively. Utilizing regression analyses and ANOVA, it is discovered that seasonal variation was not important in contributing traffic accidents, and Saturday peak was not ascertained. A non linear relationship between accident occurrence and various rain conditions was found. Accident numbers increased till rain exceeded 50.0 mm. High traffic volume and low speed urban driving in Hong Kong can be the major cause of traffic accidents on rainy days. The impact of heat stress on accident occurrence was found to be statistically significant.展开更多
用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶...用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶片长度随着降雨量和灌溉次数变化而呈现波动式消长规律。对照和轻度践踏的草坪密度随着践踏时期的延长而呈现持续下降的趋势,但中度和重度践踏的草坪密度在9月份时呈现增加的趋势,并且重度践踏草坪增加的幅度明显高于中度践踏;轻度、中度、重度践踏草坪的地上活生物量依次增加,但轻度与中度践踏在践踏的前2个月差异不显著(P>0.05),之后出现显著差异(P<0.05);而中度和重度践踏的草坪地上活生物量差异均不显著(P>0.05)。对于沟叶结缕草草坪而言,如果采取较粗放的养护措施,轻度践踏强度比较适宜即75 kg重,每隔4 d践踏10次;如果采取比较好的、适时的养护措施如适时灌溉、施肥和封闭恢复,中度践踏强度(即75 kg重,每隔2 d践踏10次)也可以维持比较好的草坪坪用质量。展开更多
Objective: To explore the stress effects of traffic accident on changing the NO level and SOD activity, as well as the relationship between personality and prognostic change. Methods: Serum level of NO and activity of...Objective: To explore the stress effects of traffic accident on changing the NO level and SOD activity, as well as the relationship between personality and prognostic change. Methods: Serum level of NO and activity of SOD were measured in 152 patients with traffic accidents and in 60 control subjects. All subjects were assessed with the Eysenck Personality Questionnaire (EPQ). Results: NO and SOD were significantly higher in patients as compared to controls ( P <0.01). Correlation analysis showed that SOD score negatively correlated with N score of EPQ ( P <0.05), and NO score positively correlated with N and P scores of EPQ ( P <0.05).Conclusion: Healthy personality may play an important role to enhance the ability to cope with stress.展开更多
以四川地区地应力实测资料为基础，采用地质过程数值模拟的三维有限元数值分析方法，对四川省“Y 字形”断裂交汇部区域应力场进行反演分析，得到四川省“Y 字形”断裂交汇部周围地区不同埋深的地应力分布情况及数值大小。区域最大水平...以四川地区地应力实测资料为基础，采用地质过程数值模拟的三维有限元数值分析方法，对四川省“Y 字形”断裂交汇部区域应力场进行反演分析，得到四川省“Y 字形”断裂交汇部周围地区不同埋深的地应力分布情况及数值大小。区域最大水平主应力总体为 NW 向，但中部、东北侧部分区域有 NE 向出现。本区内埋深500 m 最大水平应力为12．5～15 MPa，1000 m 最大水平应力为26～30 MPa，1500 m 最大水平应力为38～44 MPa，2000 m 最大水平应力为50～57．5 MPa。同时，在前人对四川省地应力3个大区分区的基础上，根据反演得到的区域地应力大小及方向，又将“Y 字形”区域各分为2～3个亚区，为该区域其他公路、铁路以及隧道工程的选线提供了参考资料。展开更多
文摘Background: Cycling currently comprises only 1% of transport trips in the U.S. despite benefits for air pollution, traffic congestion, and improved public health. Methods: Building upon the Level of Traffic Stress (LTS) methodology, we assessed GPS trip data from utilitarian cyclists to understand route preferences and the level of low stress cycling connection between origins and destinations. GPS data were obtained from adult transport cyclists over multiple days. All bikeable road segments in the network were assigned an LTS score. The shortest paths between each origin and destination along bikeable roadways and along low stress (LTS 1 or 2) routes were calculated. Route trajectories were mapped to the LTS network, and the LTS and distances of observed, the shortest and low stress routes were compared. LTS maps and animations were developed to highlight where low stress connections were lacking. Results: There were 1038 unique cycling trips from 87 participants included in the analysis. An exclusively low stress route did not exist for 51% of trips. Low stress routes that were possible were, on average, 74% longer than the shortest possible path and 56% longer than the observed route. Observed routes were longer and lower stress than the shortest possible route. Conclusions: Results indicate that transport cyclists traveled beyond low stress residential areas and that low stress routes with acceptable detour distances were lacking. Cyclists appeared to weigh both route distance and quality and were willing to trade maximum directness for lower stress. GPS data provide additional information to support planning decisions to increase the impact of infrastructure investments on cycling mode share.
文摘Environmental stress model is proposed as an effective tool to the analysis and evaluation of navigational safety in ports and waterways. Marine traffic simulations are carried out in a virtual port area with various arrangements and conditions. Calculations of stress values and traffic volume criteria are illustrated. The simulation results provide a valuable hint for safety management of vessel traffic. The model provides quantitative information and helps administrators in decision making to achieve desired safety level and improve the efficiency of vessel traffic in ports and waterways.
文摘The influence of rainfall and thermal stress in accident occurrence for the period 1985 through 1994 in Hong Kong was investigated. The existence of seasonal variations and weekly cycle was also examined. Daity accident and meteorological data were obtained from the Transport Department and the Hong Kong Observatory respectively. Utilizing regression analyses and ANOVA, it is discovered that seasonal variation was not important in contributing traffic accidents, and Saturday peak was not ascertained. A non linear relationship between accident occurrence and various rain conditions was found. Accident numbers increased till rain exceeded 50.0 mm. High traffic volume and low speed urban driving in Hong Kong can be the major cause of traffic accidents on rainy days. The impact of heat stress on accident occurrence was found to be statistically significant.
文摘用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶片长度随着降雨量和灌溉次数变化而呈现波动式消长规律。对照和轻度践踏的草坪密度随着践踏时期的延长而呈现持续下降的趋势,但中度和重度践踏的草坪密度在9月份时呈现增加的趋势,并且重度践踏草坪增加的幅度明显高于中度践踏;轻度、中度、重度践踏草坪的地上活生物量依次增加,但轻度与中度践踏在践踏的前2个月差异不显著(P>0.05),之后出现显著差异(P<0.05);而中度和重度践踏的草坪地上活生物量差异均不显著(P>0.05)。对于沟叶结缕草草坪而言,如果采取较粗放的养护措施,轻度践踏强度比较适宜即75 kg重,每隔4 d践踏10次;如果采取比较好的、适时的养护措施如适时灌溉、施肥和封闭恢复,中度践踏强度(即75 kg重,每隔2 d践踏10次)也可以维持比较好的草坪坪用质量。
文摘Objective: To explore the stress effects of traffic accident on changing the NO level and SOD activity, as well as the relationship between personality and prognostic change. Methods: Serum level of NO and activity of SOD were measured in 152 patients with traffic accidents and in 60 control subjects. All subjects were assessed with the Eysenck Personality Questionnaire (EPQ). Results: NO and SOD were significantly higher in patients as compared to controls ( P <0.01). Correlation analysis showed that SOD score negatively correlated with N score of EPQ ( P <0.05), and NO score positively correlated with N and P scores of EPQ ( P <0.05).Conclusion: Healthy personality may play an important role to enhance the ability to cope with stress.
文摘以四川地区地应力实测资料为基础，采用地质过程数值模拟的三维有限元数值分析方法，对四川省“Y 字形”断裂交汇部区域应力场进行反演分析，得到四川省“Y 字形”断裂交汇部周围地区不同埋深的地应力分布情况及数值大小。区域最大水平主应力总体为 NW 向，但中部、东北侧部分区域有 NE 向出现。本区内埋深500 m 最大水平应力为12．5～15 MPa，1000 m 最大水平应力为26～30 MPa，1500 m 最大水平应力为38～44 MPa，2000 m 最大水平应力为50～57．5 MPa。同时，在前人对四川省地应力3个大区分区的基础上，根据反演得到的区域地应力大小及方向，又将“Y 字形”区域各分为2～3个亚区，为该区域其他公路、铁路以及隧道工程的选线提供了参考资料。
