Mangshan pitviper, Protobothrops mangshanensis （formerly Zhaoermia mangshanensis） is endemic to China. Unfortunately, due to the decreasing size of its wild populations, this snake has been listed as critically enda...Mangshan pitviper, Protobothrops mangshanensis （formerly Zhaoermia mangshanensis） is endemic to China. Unfortunately, due to the decreasing size of its wild populations, this snake has been listed as critically endangered. Re- search carried out on the Mangshan pitviper＇s population ecology and captive reproduction has revealed that the unique head patch patterns of different individuals may potentially be used as a noninvasive recognition biometric character. We collected head patch pattern images of 40 individuals of P. mangshanensis between 1994 and 2011. By comparing each pitviper＇s head patch pattern, we found that the head patch pattern of individual snakes was different and unique. Additionally, we observed and recorded the head patch pattern characters of four adults and five juveniles before and af- ter ecdysis. Our findings confirmed that head patch patterns of Mangshan pitvipers are unique and stable, remaining un- changed after ecdysis. Thus, individuals can be quickly identified by examining the head patch pattern within a specific recognition area on the head. This method may be useful for noninvasive individual recognition in many other species that display color patch pattern variations, especially in studies of endangered species where the use of invasive marking techniques is undesirable.展开更多
The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dim...The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dimensional （3D） turbulence flow in conduits is an important method to study the hydraulic performance and conduct an optimum hydraulic design for the conduits. With the analyses of the flow patterns in the inlet and outlet conduits, the boundary conditions of the numerical simulation for them can be determined. The main obtained conclusions are as follows： （i） Under normal operation conditions, there is essentially no pre-swirl flow at the impeller chamber inlet of an axial-flow pump system, based on which the boundary condition at the inlet conduit may be defined. （ii） The circulation at the guide vane outlet of an axial-flow pump system has a great effect on the hydraulic performance of the outlet conduit, and there is optimum circulation for the performance. Therefore, it is strongly suggested to design the guide vane according to the optimum circulation. （iii） The residual circulation at the guide vane outlet needs to be considered for the inlet boundary condition of the outlet conduit, and the value of the circulation may be measured in a specially designed test model.展开更多
Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. S...Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. So in order to avoid the careless driving, a system which can measure the posture of a driver and warns driver to drive carefully in the case of looking aside is necessary. Although the image measurement method is used broadly, there is a problem on which measurement accuracy is influenced by environment light, makeup of the driver, etc. in the general method based on the two-dimensional image. Therefore, in this study, we propose an image measurement method to obtain the head posture of driver. First we use three-dimensional measurement method which based on the infrared pattern projection to get 3-D information of head, and then we calculate the angle for faces. In this paper, we explain the composition method of an experiment system, and the results of head posture measurement experiment.展开更多
目的利用英国生物银行(United Kingdom Biobank,UKB)数据,系统地分析饮食因素与头颈部肿瘤(head and neck cancer,HNC)风险关系,为肿瘤防治提供参考。方法选取UKB数据,基于食物频率问卷(food frequency questionnaire,FFQ)的基线数据,...目的利用英国生物银行(United Kingdom Biobank,UKB)数据,系统地分析饮食因素与头颈部肿瘤(head and neck cancer,HNC)风险关系,为肿瘤防治提供参考。方法选取UKB数据,基于食物频率问卷(food frequency questionnaire,FFQ)的基线数据,通过主成分分析确定了3种主要的饮食模式。采用Cox比例风险模型研究单种食物和饮食模式与HNC风险的关系。结果来自UKB的395500名参与者被纳入研究,中位随访时间为7.13(6.44,7.73)年,共发生了462例HNC。关联分析发现,经常摄入谷物(HR=0.79,95%CI:0.61~1.01)和面包(HR=0.77,95%CI:0.59~1.00)与较低的HNC风险有关。茶叶摄入的趋势性检验差异有统计学意义(Z=-1.80,P=0.064)。开放三明治式饮食模式存在剂量反应趋势(Z=-1.81,P=0.071),随着摄入量的增加,保护作用增强。结论单一食物谷物、面包、茶的摄入,以及以高比例摄入全谷物和富膳食纤维食物为特征的饮食模式,与较低的HNC风险相关。展开更多
基金funded by the National Natural Science Foundation of China (No. 31071946)the Wild Animal Conservation Fund of the State Forestry Administration of China (2011)the Provincial Natural Science Foundation of Hunan, China (No. 09JJ3030)
文摘Mangshan pitviper, Protobothrops mangshanensis （formerly Zhaoermia mangshanensis） is endemic to China. Unfortunately, due to the decreasing size of its wild populations, this snake has been listed as critically endangered. Re- search carried out on the Mangshan pitviper＇s population ecology and captive reproduction has revealed that the unique head patch patterns of different individuals may potentially be used as a noninvasive recognition biometric character. We collected head patch pattern images of 40 individuals of P. mangshanensis between 1994 and 2011. By comparing each pitviper＇s head patch pattern, we found that the head patch pattern of individual snakes was different and unique. Additionally, we observed and recorded the head patch pattern characters of four adults and five juveniles before and af- ter ecdysis. Our findings confirmed that head patch patterns of Mangshan pitvipers are unique and stable, remaining un- changed after ecdysis. Thus, individuals can be quickly identified by examining the head patch pattern within a specific recognition area on the head. This method may be useful for noninvasive individual recognition in many other species that display color patch pattern variations, especially in studies of endangered species where the use of invasive marking techniques is undesirable.
基金Project supported by the Natural Science Foundation of Jiangsu Higher Education Institutions ofChina(No.12KJD570001)
文摘The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dimensional （3D） turbulence flow in conduits is an important method to study the hydraulic performance and conduct an optimum hydraulic design for the conduits. With the analyses of the flow patterns in the inlet and outlet conduits, the boundary conditions of the numerical simulation for them can be determined. The main obtained conclusions are as follows： （i） Under normal operation conditions, there is essentially no pre-swirl flow at the impeller chamber inlet of an axial-flow pump system, based on which the boundary condition at the inlet conduit may be defined. （ii） The circulation at the guide vane outlet of an axial-flow pump system has a great effect on the hydraulic performance of the outlet conduit, and there is optimum circulation for the performance. Therefore, it is strongly suggested to design the guide vane according to the optimum circulation. （iii） The residual circulation at the guide vane outlet needs to be considered for the inlet boundary condition of the outlet conduit, and the value of the circulation may be measured in a specially designed test model.
文摘Although automobile is an indispensable vehicle to modern life, it also serves as a social problem with a big traffic accident. Among the reasons of traffic accidents, careless driving accounts for the largest part. So in order to avoid the careless driving, a system which can measure the posture of a driver and warns driver to drive carefully in the case of looking aside is necessary. Although the image measurement method is used broadly, there is a problem on which measurement accuracy is influenced by environment light, makeup of the driver, etc. in the general method based on the two-dimensional image. Therefore, in this study, we propose an image measurement method to obtain the head posture of driver. First we use three-dimensional measurement method which based on the infrared pattern projection to get 3-D information of head, and then we calculate the angle for faces. In this paper, we explain the composition method of an experiment system, and the results of head posture measurement experiment.
文摘目的利用英国生物银行(United Kingdom Biobank,UKB)数据,系统地分析饮食因素与头颈部肿瘤(head and neck cancer,HNC)风险关系,为肿瘤防治提供参考。方法选取UKB数据,基于食物频率问卷(food frequency questionnaire,FFQ)的基线数据,通过主成分分析确定了3种主要的饮食模式。采用Cox比例风险模型研究单种食物和饮食模式与HNC风险的关系。结果来自UKB的395500名参与者被纳入研究,中位随访时间为7.13(6.44,7.73)年,共发生了462例HNC。关联分析发现,经常摄入谷物(HR=0.79,95%CI:0.61~1.01)和面包(HR=0.77,95%CI:0.59~1.00)与较低的HNC风险有关。茶叶摄入的趋势性检验差异有统计学意义(Z=-1.80,P=0.064)。开放三明治式饮食模式存在剂量反应趋势(Z=-1.81,P=0.071),随着摄入量的增加,保护作用增强。结论单一食物谷物、面包、茶的摄入,以及以高比例摄入全谷物和富膳食纤维食物为特征的饮食模式,与较低的HNC风险相关。
