QINGHAI Province, on the Qinghai-Tibet Plateau, is to many people a remote and mysterious place. This reporter recently traveled with the 2002 Qinghai in Focus Photographers Group on their trip from the Qinghai hinter...QINGHAI Province, on the Qinghai-Tibet Plateau, is to many people a remote and mysterious place. This reporter recently traveled with the 2002 Qinghai in Focus Photographers Group on their trip from the Qinghai hinterland on the northern part of the plateau to Golmud, the Kunlun Mountains, and the Qinghai-Tibet Railway construction site.Golmud, Born with the HighwayIt took us 2 hours and 10 minutes to fly the 1,150 kilometer distance from Beijing to Xining, capital city of Qinghai Province. From there we boarded a train that went directly west to Golmud.展开更多
The factor of human project activity is often the immediate cause resulting in soil and water loss. The Baoji-Lanzhou second railway in construction is an example. The soil and water loss law caused by earth and stone...The factor of human project activity is often the immediate cause resulting in soil and water loss. The Baoji-Lanzhou second railway in construction is an example. The soil and water loss law caused by earth and stone mountain railway engineering construction in the northwestern China is studied systematically and that caused possibly by the road bed project, the road moat project, the field project, the tunnel project and the service road project in construction is probed. At the same time, the type, t...展开更多
The anomalous movements of glaciers cause disasters,such as debrisflows and landslides.It is very important to assess the glacier movements and their future trends.Glacier velocity refers to movement process.The curre...The anomalous movements of glaciers cause disasters,such as debrisflows and landslides.It is very important to assess the glacier movements and their future trends.Glacier velocity refers to movement process.The current research aims to analyse past and current spatiotemporal changes in glacier velocity.No study has used neural network model to conduct a spatiotemporal prediction for glacier velocity.Therefore,this paper selected typical mountain glaciers G2 and G5 along the Sichuan-Tibet Railway as research objects and constructed the Convolutional Gate Recurrent Unit(ConvGRU)spatiotemporal prediction model based on 1988–2018 Landsat data to predict velocities in 2019–2028,and analysed the future trends of G2 and G5.The evaluation indexes met the model requirements to a large extent,quantitatively showing that the model has high accuracy and can successfully capture thefluctuation changes in time series data of glacier velocity.The mean deviations of G2 and G5 were 0.09 and-0.47 m/yr,respectively,reflecting the high reliability of the model applied to extraction of glacier velocity.The velocities of G2 and G5 showed a slow downtrend withfluctuations;that is,they will not cause damage to the construction and operation of the Sichuan-Tibet Railway in the short term.展开更多
Background It is important to determine the incidence of acute mountain sickness (AMS) among workers at altitudes between 3500 m and 5000 m on Mt. Tanggula during the construction of the Qinghai-Tibet railroad. This...Background It is important to determine the incidence of acute mountain sickness (AMS) among workers at altitudes between 3500 m and 5000 m on Mt. Tanggula during the construction of the Qinghai-Tibet railroad. This study explored the risk factors predisposing workers to developing AMS and attempted to develop more effective ways of preventing and treating AMS. Methods A total of 11 182 workers were surveyed by completing twice daily a Lake Louise questionnaire, and a score 〉3 indicated AMS. The contributing risk factors were assessed for at least 2 months for the duration of the study in the years from 2001 to 2003. A risk model was developed by multiple Logistic regression. Standard statistica~ methods were used to analyze data. Results AMS occurred in 56% of workers working at high altitudes on Mt. Tanggula. The incidence of AMS increased with increasing altitude. Rapid ascent to an altitude above 3500 m, sea-level or lowland newcomers, young people under 25 years of age, heavy physical exertion, obese person, and arterial oxygen saturation (SaO2) below 80% were independent AMS risk factors. No significant association was found between AMS and sex or taking Rhodiola. Medical education contributed to an early diagnosis of AMS. Conclusions This study used the Lake Louise scoring system suggesting that it is a well-validated standard for field evaluation of AMS and for making an early diagnosis. These studies have described many variables regarding risk factors for the development of AMS. Risk factors which can be modified should be attended to, and the physicians should carry out check-ups and tests to identify subjects who are more at risk. Prevention consists in continuous gradual ascent, medical education, and prompt descent to avoid progression in patients with serious AMS. It is most important to effectively control the risk factors of AMS.展开更多
文摘QINGHAI Province, on the Qinghai-Tibet Plateau, is to many people a remote and mysterious place. This reporter recently traveled with the 2002 Qinghai in Focus Photographers Group on their trip from the Qinghai hinterland on the northern part of the plateau to Golmud, the Kunlun Mountains, and the Qinghai-Tibet Railway construction site.Golmud, Born with the HighwayIt took us 2 hours and 10 minutes to fly the 1,150 kilometer distance from Beijing to Xining, capital city of Qinghai Province. From there we boarded a train that went directly west to Golmud.
文摘The factor of human project activity is often the immediate cause resulting in soil and water loss. The Baoji-Lanzhou second railway in construction is an example. The soil and water loss law caused by earth and stone mountain railway engineering construction in the northwestern China is studied systematically and that caused possibly by the road bed project, the road moat project, the field project, the tunnel project and the service road project in construction is probed. At the same time, the type, t...
基金supported by the National Scientific Foundation of China[grant number 42161063]Open Foundation of Key Laboratory of Yellow River Water Environment in Gansu Province[grant number 121YRWEK001]+4 种基金Science and Technology Plan of Gansu Province[grant number 20JR2RA002]Natural Science Foundation of Gansu Province[grant number 20JR10RA249]Youth Science and Technology Foundation of Gansu Province[grant number 20JR10RA272]Lanzhou Jiaotong University-Tianjin University Innovation Project Fund Project[grant number 2020055]Jiayuguan City 2021 Science and Technology Plan Projects[grant number 21-35].
文摘The anomalous movements of glaciers cause disasters,such as debrisflows and landslides.It is very important to assess the glacier movements and their future trends.Glacier velocity refers to movement process.The current research aims to analyse past and current spatiotemporal changes in glacier velocity.No study has used neural network model to conduct a spatiotemporal prediction for glacier velocity.Therefore,this paper selected typical mountain glaciers G2 and G5 along the Sichuan-Tibet Railway as research objects and constructed the Convolutional Gate Recurrent Unit(ConvGRU)spatiotemporal prediction model based on 1988–2018 Landsat data to predict velocities in 2019–2028,and analysed the future trends of G2 and G5.The evaluation indexes met the model requirements to a large extent,quantitatively showing that the model has high accuracy and can successfully capture thefluctuation changes in time series data of glacier velocity.The mean deviations of G2 and G5 were 0.09 and-0.47 m/yr,respectively,reflecting the high reliability of the model applied to extraction of glacier velocity.The velocities of G2 and G5 showed a slow downtrend withfluctuations;that is,they will not cause damage to the construction and operation of the Sichuan-Tibet Railway in the short term.
基金This study was supported by the grants from National Natural Science Foundation of China (No. 30393130) and the 973 Program of China (No. 2006CB708514).
文摘Background It is important to determine the incidence of acute mountain sickness (AMS) among workers at altitudes between 3500 m and 5000 m on Mt. Tanggula during the construction of the Qinghai-Tibet railroad. This study explored the risk factors predisposing workers to developing AMS and attempted to develop more effective ways of preventing and treating AMS. Methods A total of 11 182 workers were surveyed by completing twice daily a Lake Louise questionnaire, and a score 〉3 indicated AMS. The contributing risk factors were assessed for at least 2 months for the duration of the study in the years from 2001 to 2003. A risk model was developed by multiple Logistic regression. Standard statistica~ methods were used to analyze data. Results AMS occurred in 56% of workers working at high altitudes on Mt. Tanggula. The incidence of AMS increased with increasing altitude. Rapid ascent to an altitude above 3500 m, sea-level or lowland newcomers, young people under 25 years of age, heavy physical exertion, obese person, and arterial oxygen saturation (SaO2) below 80% were independent AMS risk factors. No significant association was found between AMS and sex or taking Rhodiola. Medical education contributed to an early diagnosis of AMS. Conclusions This study used the Lake Louise scoring system suggesting that it is a well-validated standard for field evaluation of AMS and for making an early diagnosis. These studies have described many variables regarding risk factors for the development of AMS. Risk factors which can be modified should be attended to, and the physicians should carry out check-ups and tests to identify subjects who are more at risk. Prevention consists in continuous gradual ascent, medical education, and prompt descent to avoid progression in patients with serious AMS. It is most important to effectively control the risk factors of AMS.