Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningf...Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems.Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures(5℃/1℃, 15℃/5℃, 20℃/5℃, 25℃/10℃ and 30℃/15℃) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016.Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light.We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination.It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures.There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination.Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow.Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer.Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.展开更多
由于新型冠状病毒肺炎的爆发,口罩成为人们日常生活中必需品。为了识别与检测人们是否佩戴口罩,提出了一种基于改进的YOLOv5s口罩佩戴检测算法。通过在YOLOv5s主干网络引入改进的自适应的协调注意力机制模块(Coordinate attention-activ...由于新型冠状病毒肺炎的爆发,口罩成为人们日常生活中必需品。为了识别与检测人们是否佩戴口罩,提出了一种基于改进的YOLOv5s口罩佩戴检测算法。通过在YOLOv5s主干网络引入改进的自适应的协调注意力机制模块(Coordinate attention-activate or not,CA-A)提升网络的特征提取能力,解决了错误检测和漏检的问题。以新的损失函数AD-CIoU代替CIoU损失函数,作为回归损失函数,提升了边界框的定位精确度。实验表明,与原始模型算法相比,所提出的模型算法平均精度mAP值达到96.1%,提升了1.7%,具有较好的检测精度,可以满足目标检测应用需求。展开更多
基金funded by the Science and Technology Plan Project of Xinjiang Uygur Autonomous Region (2016B03040)the National Natural Science Foundation of China (31570529, 31660162, 31971428, 31770638)the Youth Innovation Promotion Association of Chinese Academy of Sciences (2018477)
文摘Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems.Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures(5℃/1℃, 15℃/5℃, 20℃/5℃, 25℃/10℃ and 30℃/15℃) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016.Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light.We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination.It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures.There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination.Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow.Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer.Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.
文摘由于新型冠状病毒肺炎的爆发,口罩成为人们日常生活中必需品。为了识别与检测人们是否佩戴口罩,提出了一种基于改进的YOLOv5s口罩佩戴检测算法。通过在YOLOv5s主干网络引入改进的自适应的协调注意力机制模块(Coordinate attention-activate or not,CA-A)提升网络的特征提取能力,解决了错误检测和漏检的问题。以新的损失函数AD-CIoU代替CIoU损失函数,作为回归损失函数,提升了边界框的定位精确度。实验表明,与原始模型算法相比,所提出的模型算法平均精度mAP值达到96.1%,提升了1.7%,具有较好的检测精度,可以满足目标检测应用需求。
