The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing ...The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains illdefined.We present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument measurements.Variations in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2021,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2000,and a clear recent increasing period from 2000 to 2021.We further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2100.展开更多
In order to study the nodes importance and its evolution process of the railway network of SREB (Silk Road Economic Belt), we construct the network (RNSREB) based on Graph Theory, which focuses on the time intervals a...In order to study the nodes importance and its evolution process of the railway network of SREB (Silk Road Economic Belt), we construct the network (RNSREB) based on Graph Theory, which focuses on the time intervals according to actually railway network, railway project under construction and the national railway network of medium-and long-term plan. The algorithms for vital nodes evaluation are analyzed, the evaluation method on nodes importance of RNSREB is proposed, the quantized values of each node are calculated with Pajek, and TOP20 core nodes of the network with different coefficients and time intervals are determined respectively. Then the evolution process of TOP20 critical nodes with 4 periods is contrasted and analyzed. It is indicated that some vital nodes newly discovered (Geermu, Maduo, Ruoqiang) should be concerned.展开更多
In order to study the nodes importance of the aviation network of SREB (Silk Road Economic Belt), we construct the network (ANSREB) based on Graph Theory that focused on the actually situation of civil aviation transp...In order to study the nodes importance of the aviation network of SREB (Silk Road Economic Belt), we construct the network (ANSREB) based on Graph Theory that focused on the actually situation of civil aviation transportation of SREB. We analyzed the evaluation algorithms for nodes importance, proposed the evaluation method for nodes importance of ANSREB;the quantized values of each node (Degree, Betweennesss, Closeness) are calculated with Pajek and traffic data, and determined TOP 20 critical nodes of the network on two different conditions respectively (without and within International routes). Then we contrasted and analyzed the reason that affects the ranking of those vital nodes, which has the character of highly concentration of business and dominant status.展开更多
The Yellow River Basin(YRB) is characterized by active geological and tectonic processes, rapid geomorphological evolution, and distinct climatic diversity. Correspondingly, major disasters in the YRB are characterize...The Yellow River Basin(YRB) is characterized by active geological and tectonic processes, rapid geomorphological evolution, and distinct climatic diversity. Correspondingly, major disasters in the YRB are characterized by varied types,extensive distributions, and sudden occurrences. In addition, major disasters in the YRB usually evolve into disaster chains that cause severe consequences. Therefore, major disasters in the YRB destroy ecologies and environments and influence geological and ecological safety in the basin. This paper systematically reviews research on geological and surface processes, major disaster effects, and risk mitigation in the YRB, discusses the trends and challenges of relevant research, analyzes the key scientific problems that need to be solved, and suggests prospects for future research based on the earth system science concept. Themes of research that should be focused on include geological, surface and climatic processes in the YRB and their interlinking disaster gestation mechanisms;formation mechanisms and disaster chain evolutions of giant landslides in the upper reach of the YRB;mechanisms and disaster chain effects of loess water-soil disasters in the middle reach of the YRB;occurrence patterns and amplifying effects of giant flood chains in the lower reach of the YRB;and risk mitigations of major disasters in the YRB. Key scientific problems that need to be solved are as follows: how to reveal the geological, surface and climatic processes that are coupled and interlinked with gestation mechanisms of major disasters;how to clarify the mutual feedback effects between major disasters and ecology;and how to develop a human-environmental harmony-based integrated risk mitigation system for major disasters. Prospects for future studies that follow the earth system science concept include the following: highlighting interdisciplinary research to reveal the interlinked disaster gestation mechanisms of the geology, surface and climate in the YRB in the past, present, and future;forming theories to clarify the regional patterns, dynamic mechanisms, and mutual-feedback effects between disaster chains and ecology in the YRB on land and in rivers in the region;solving technological bottlenecks to develop assessment models and mitigation theories for integrated risks in the YRB by following the human-environment harmony concept;and finally, establishing a demonstratable application pattern characterized by "whole-basin coverage" and "zonal controls", thereby guaranteeing ecological and geological safety in the basin and providing scientific support for ecological conservation and high-quality development of the YRB.展开更多
Unmanned Aircraft Systems(UASs) have advanced technologically and surged exponentially over recent years. Currently, due to safety concerns, most civil operations of UAS are conducted in low-level uncontrolled area or...Unmanned Aircraft Systems(UASs) have advanced technologically and surged exponentially over recent years. Currently, due to safety concerns, most civil operations of UAS are conducted in low-level uncontrolled area or in segregated controlled airspace. As the industry progresses, both operational and technological capabilities have matured to the point where UASs are expected to gain greater freedom of access to both controlled and uncontrolled airspace. Extensive technical and regulatory surveys have been conducted to enable the expanded operations. However, most surveys are derived from the perspective of UAS own operating mechanism and barely consider interactions of their non-segregated activities with the Air Traffic Management(ATM) system. Hence, to fill the gap, this paper presents a survey conducted from the perspective of Air Navigation Service Provider(ANSP), which serves to accommodate these new entrants to the overall national airspace while continuing flight safety and efficiency. The primary objectives of this paper are to:(A) describe what typical ANSP-supplied UAS Traffic Management(UTM) architecture is required to facilitate all types of civil UAS operations;(B) identify three major ANSP considerations on how UAS can be accommodated safely in civil airspace;(C) outline future directions and challenges related with UAS operations for the ANSP.展开更多
OBJECTIVE: To explore the relationships between different lifestyle-behavioral factors and phlegm wetness type of Traditional Chinese Medicine constitution,so as to provide health management strategies for phlegm-wetn...OBJECTIVE: To explore the relationships between different lifestyle-behavioral factors and phlegm wetness type of Traditional Chinese Medicine constitution,so as to provide health management strategies for phlegm-wetness constitution.METHODS: A case-control study was conducted with the cases selected from the database of Chinese constitution survey in 9 provinces or municipalities of China. 1380 cases met the diagnostic criteria of phlegm-wetness type were taken as the case group, and 1380 cases were randomly selected from gentleness type as the control group. Using Chi-square test to compare the differences of lifestyle-behavior composition in each group; single factor and multiple logistic regression analysis were used to compare the relationships of life-style-behavioral factors and phlegm-wetness type.RESULTS: There were statistically significant differences between phlegm-wetness type group and gentleness type group in lifestyle behaviors(dietary habits, tobacco and liquor consumptions, exercise habits, sleeping habits). The results of single factor logistic regression analysis demonstrated that the risk of phlegm-wetness constitution decreased significantly in light diet(odds ratio, OR=0.68);The risk factors of phlegm-wetness type were fatty food intake(OR=2.36), sleeping early and getting up late(OR=1.87), tobacco smoking(OR=1.83),barbecued food intake(OR=1.68), alcohol drinking(OR=1.63), salty food intake(OR=1.44), sleeping erratically(OR=1.43), less physical activities(OR=1.42), sweet food intake(OR=1.29), sleeping and getting up late(OR=1.26), and pungent food intake(OR=1.21), respectively. Regardless of the interaction among lifestyle-behavioral factors, the results of the multiple logistic regression analysis revealed that the risk factors of phlegm-wetness type were sleeping early and getting up late(OR=1.94), fatty food intake(OR=1.80), tobacco smoking(OR=1.50),sleeping erratically(OR=1.50), barbecued food intake(OR=1.40), sleeping and getting up late(OR=1.40), less physical activities(OR=1.31), sleeping late and getting up early(OR=1.27),and sweet food intake(OR=1.27), respectively, and the risk ofphlegm-wetness type still decreased significantly inlightfoodintake(OR=0.79).CONCLUSION: Light diet can decrease the risk of being phlegm-wetness constitution, and bad lifestyle behaviors such as sleeping early and getting up late, sleeping erratically, fatty food, barbecued food or sweet food intake, tobacco and liquor consumptions, and less physical activities can increase the risks of becoming phlegm-wetness constitution.展开更多
Sebaceous carcinoma (SC) of the eyelid is a rare but aggressive malignancy, accounting for 3%—5% of eyelid malignancies in the United States, and up to 35% in Asian populations (Deprez and Uffer, 2009;Xu et al., 2018...Sebaceous carcinoma (SC) of the eyelid is a rare but aggressive malignancy, accounting for 3%—5% of eyelid malignancies in the United States, and up to 35% in Asian populations (Deprez and Uffer, 2009;Xu et al., 2018;Yu et al., 2018). It is frequently mistaken for benign conditions or less aggressive malignancies such as basal cell carcinoma (Muqit et al., 2013), and the effects of delay in diagnosis can be devastating to patients. Aggressive surgical resection is the primary treatment of these tumors and often invoIves orbital exenteration with significant morbidity to patients, and these tumors frequently recur, with local recurrence rate as high as 18%. Importantly, this disease has a high metastatic potential, and there are very limited data guiding systemic treatment options;ultimately 6%—18% of patients diagnosed with SC of the eyelid succumb to metastatic disease (Zurcher et al., 1998;Shields et al., 2004).展开更多
On 4 April 2013,a 1.5 million cubic meter landslide occurred in Sunjia Town,Wanzhou County,Three Gorges Reservoir,China.After initiation,the Sunjia landslide traveled about 30 m toward the northeast and destroyed most...On 4 April 2013,a 1.5 million cubic meter landslide occurred in Sunjia Town,Wanzhou County,Three Gorges Reservoir,China.After initiation,the Sunjia landslide traveled about 30 m toward the northeast and destroyed most of the infrastructure in its path.The landslide was triggered by heavy rainfall and previous slope excavations,but this slope also displayed a complicated failure process:the overlying earth slope first deformed and then induced sliding along underlying rock surfaces.Surface displacements that resulted from continuous creeping of the post-event slope were observed by an emergency monitoring system that revealed the disequilibrium state of the slope.To discuss the stability and future movements of the remaining unstable debris deposits,we developed a geotechnical model of the post-slide slope,calculated how it can slide again in an extreme rainfall scenario,and estimated the potential runout distance using the Tsunami Squares method.We then estimated the number of people and the value of the infrastructure threatened by this potential landslide.Lastly,we analyzed the vulnerability of elements at risk and quantitatively evaluated the hazard risk associated with the most dangerous scenario.This quantitative risk analysis provides a better understanding of,and technical routes for,hazard mitigation of rainfallinduced complex landslides.展开更多
OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sam...OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sample of 8448subjects from nine provinces and municipalities was chosen from the database of the TCM constitution and health status survey.Constituent ratio and correspondence analysis were used to find the relationship between smoking and drinking and TCM constitution.RESULTS:There was an association between smokinganddrinkingandtheGentleness,phlegm-dampness,and dampness-heat type constitutions.People that did not smoke tobacco or drink alcohol tended to have Yang-deficiency,Yin-deficiency,Qi-depression,Qi-deficiency,special diathesis,orblood-stasis type constitutions.CONCLUSION:There was a significant correlation between tobacco and alcohol use and TCM constitutions.To improve patient health,more attention should be paid to tobacco and alcohol control.展开更多
Dual-Frequency Ground-Based Augmentation Systems(GBAS)can be affected by receiver Inter-Frequency Bias(IFB)when Ionosphere-Free(Ifree)smoothing is applied.In the framework of the proposed GBAS Approach Service Type F(...Dual-Frequency Ground-Based Augmentation Systems(GBAS)can be affected by receiver Inter-Frequency Bias(IFB)when Ionosphere-Free(Ifree)smoothing is applied.In the framework of the proposed GBAS Approach Service Type F(GAST-F),the IFB in the Ifree smoothed pseudorange can be corrected.However,IFB residual uncertainty still exists,which may threaten the integrity of the system.This paper presents an improved algorithm for the airborne protection level considering the residual uncertainty of IFBs to protect the integrity of dual-frequency GBAS.The IFB residual uncertainty multiplied by a frequency factor is included in the Ifree protection level together with the uncertainty of other error sources.To verify the proposed protection level algorithm,we calculate the IFB residual uncertainties of ground reference receivers and user receiver based on BDS B1I and B3I dual-frequency observation data and carry out a test at the Dongying Airport GBAS station.The results show that the proposed Ifree protection level with IFB residual uncertainty is 1.48 times the current protection level on average.The probability of Misleading Information(MI)during the test is reduced from 3.2×10^(-4)to the required value.It is proven that the proposed protection level can significantly reduce the integrity risk brought by IFB residual uncertainty and protect the integrity of dual-frequency GBAS.展开更多
Detecting and characterizing Total Electron Content(TEC)depletion is important for studying the ionospheric threat due to the Equatorial Plasma Bubble(EPB)when applying the Ground-Based Augmentation System(GBAS)at low...Detecting and characterizing Total Electron Content(TEC)depletion is important for studying the ionospheric threat due to the Equatorial Plasma Bubble(EPB)when applying the Ground-Based Augmentation System(GBAS)at low latitudes.This paper develops a robust method to automatically identify TEC depletion and derive its parameters.The rolling barrel algorithm is used to automatically identify the TEC depletion candidate and its parameters.Then,the depletion candidates are screened by several improved techniques to distinguish actual depletions from other phenomena such as Traveling Ionospheric Disturbance(TID)or abnormal data.Next,based on the depletion signals from three triangular receivers,the method derives EPB parameters such as velocity,width and gradient.The time lag and front velocity are calculated based on crosscorrelation using TEC depletions and the geometrical distribution of three triangular receivers.The width and gradient of slope are then determined by using TEC depletion from a single receiver.By comparison,both the station-pair method and proposed method depend on the assumption that the EPB morphology is frozen during the short time when the plasma bubble moves between the receivers.However,our method relaxes the restriction that the baseline length should be shorter than the width of slope required by the station-pair.This relaxation is favorable for studying small-scale slope of depletions using stations of a longer baseline.In addition,the accuracy of the width and gradient is free of impact from hardware biases and small-scale disturbance,as it is based only on the relative TEC variation.The method is demonstrated by processing Global Positioning System(GPS)and Bei Dou Navigation Satellite System(BDS)data on 15 August,2018,in a solar minimum cycle.展开更多
基金the National Natural Science Foundation of China(Grants No.42041006,41790443 and 41927806).
文摘The Yellow River Basin(YRB)has experienced severe floods and continuous riverbed elevation throughout history.Global climate change has been suggested to be driving a worldwide increase in flooding risk.However,owing to insufficient evidence,the quantitative correlation between flooding and climate change remains illdefined.We present a long time series of maximum flood discharge in the YRB dating back to 1843 compiled from historical documents and instrument measurements.Variations in yearly maximum flood discharge show distinct periods:a dramatic decreasing period from 1843 to 1950,and an oscillating gentle decreasing from 1950 to 2021,with the latter period also showing increasing more extreme floods.A Mann-Kendall test analysis suggests that the latter period can be further split into two distinct sub-periods:an oscillating gentle decreasing period from 1950 to 2000,and a clear recent increasing period from 2000 to 2021.We further predict that climate change will cause an ongoing remarkable increase in future flooding risk and an∼44.4 billion US dollars loss of floods in the YRB in 2100.
文摘In order to study the nodes importance and its evolution process of the railway network of SREB (Silk Road Economic Belt), we construct the network (RNSREB) based on Graph Theory, which focuses on the time intervals according to actually railway network, railway project under construction and the national railway network of medium-and long-term plan. The algorithms for vital nodes evaluation are analyzed, the evaluation method on nodes importance of RNSREB is proposed, the quantized values of each node are calculated with Pajek, and TOP20 core nodes of the network with different coefficients and time intervals are determined respectively. Then the evolution process of TOP20 critical nodes with 4 periods is contrasted and analyzed. It is indicated that some vital nodes newly discovered (Geermu, Maduo, Ruoqiang) should be concerned.
文摘In order to study the nodes importance of the aviation network of SREB (Silk Road Economic Belt), we construct the network (ANSREB) based on Graph Theory that focused on the actually situation of civil aviation transportation of SREB. We analyzed the evaluation algorithms for nodes importance, proposed the evaluation method for nodes importance of ANSREB;the quantized values of each node (Degree, Betweennesss, Closeness) are calculated with Pajek and traffic data, and determined TOP 20 critical nodes of the network on two different conditions respectively (without and within International routes). Then we contrasted and analyzed the reason that affects the ranking of those vital nodes, which has the character of highly concentration of business and dominant status.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.42041006&41790443)the Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(Grant No.XDA23090301).
文摘The Yellow River Basin(YRB) is characterized by active geological and tectonic processes, rapid geomorphological evolution, and distinct climatic diversity. Correspondingly, major disasters in the YRB are characterized by varied types,extensive distributions, and sudden occurrences. In addition, major disasters in the YRB usually evolve into disaster chains that cause severe consequences. Therefore, major disasters in the YRB destroy ecologies and environments and influence geological and ecological safety in the basin. This paper systematically reviews research on geological and surface processes, major disaster effects, and risk mitigation in the YRB, discusses the trends and challenges of relevant research, analyzes the key scientific problems that need to be solved, and suggests prospects for future research based on the earth system science concept. Themes of research that should be focused on include geological, surface and climatic processes in the YRB and their interlinking disaster gestation mechanisms;formation mechanisms and disaster chain evolutions of giant landslides in the upper reach of the YRB;mechanisms and disaster chain effects of loess water-soil disasters in the middle reach of the YRB;occurrence patterns and amplifying effects of giant flood chains in the lower reach of the YRB;and risk mitigations of major disasters in the YRB. Key scientific problems that need to be solved are as follows: how to reveal the geological, surface and climatic processes that are coupled and interlinked with gestation mechanisms of major disasters;how to clarify the mutual feedback effects between major disasters and ecology;and how to develop a human-environmental harmony-based integrated risk mitigation system for major disasters. Prospects for future studies that follow the earth system science concept include the following: highlighting interdisciplinary research to reveal the interlinked disaster gestation mechanisms of the geology, surface and climate in the YRB in the past, present, and future;forming theories to clarify the regional patterns, dynamic mechanisms, and mutual-feedback effects between disaster chains and ecology in the YRB on land and in rivers in the region;solving technological bottlenecks to develop assessment models and mitigation theories for integrated risks in the YRB by following the human-environment harmony concept;and finally, establishing a demonstratable application pattern characterized by "whole-basin coverage" and "zonal controls", thereby guaranteeing ecological and geological safety in the basin and providing scientific support for ecological conservation and high-quality development of the YRB.
基金co-supported by the Outstanding Youth Fund of the National Natural Science Foundation of China (No. 61822102)the MIIT Technological Base Program (No. JSZL2016601B003)the National Key Research and Development Program (No. 2018YFB0505105)。
文摘Unmanned Aircraft Systems(UASs) have advanced technologically and surged exponentially over recent years. Currently, due to safety concerns, most civil operations of UAS are conducted in low-level uncontrolled area or in segregated controlled airspace. As the industry progresses, both operational and technological capabilities have matured to the point where UASs are expected to gain greater freedom of access to both controlled and uncontrolled airspace. Extensive technical and regulatory surveys have been conducted to enable the expanded operations. However, most surveys are derived from the perspective of UAS own operating mechanism and barely consider interactions of their non-segregated activities with the Air Traffic Management(ATM) system. Hence, to fill the gap, this paper presents a survey conducted from the perspective of Air Navigation Service Provider(ANSP), which serves to accommodate these new entrants to the overall national airspace while continuing flight safety and efficiency. The primary objectives of this paper are to:(A) describe what typical ANSP-supplied UAS Traffic Management(UTM) architecture is required to facilitate all types of civil UAS operations;(B) identify three major ANSP considerations on how UAS can be accommodated safely in civil airspace;(C) outline future directions and challenges related with UAS operations for the ANSP.
基金Supported by Research of Traditional Chinese Medicine Health cognition theory and Constitution Classification from the National Basic Research Program(973 Program)(No.2011CB505403)
文摘OBJECTIVE: To explore the relationships between different lifestyle-behavioral factors and phlegm wetness type of Traditional Chinese Medicine constitution,so as to provide health management strategies for phlegm-wetness constitution.METHODS: A case-control study was conducted with the cases selected from the database of Chinese constitution survey in 9 provinces or municipalities of China. 1380 cases met the diagnostic criteria of phlegm-wetness type were taken as the case group, and 1380 cases were randomly selected from gentleness type as the control group. Using Chi-square test to compare the differences of lifestyle-behavior composition in each group; single factor and multiple logistic regression analysis were used to compare the relationships of life-style-behavioral factors and phlegm-wetness type.RESULTS: There were statistically significant differences between phlegm-wetness type group and gentleness type group in lifestyle behaviors(dietary habits, tobacco and liquor consumptions, exercise habits, sleeping habits). The results of single factor logistic regression analysis demonstrated that the risk of phlegm-wetness constitution decreased significantly in light diet(odds ratio, OR=0.68);The risk factors of phlegm-wetness type were fatty food intake(OR=2.36), sleeping early and getting up late(OR=1.87), tobacco smoking(OR=1.83),barbecued food intake(OR=1.68), alcohol drinking(OR=1.63), salty food intake(OR=1.44), sleeping erratically(OR=1.43), less physical activities(OR=1.42), sweet food intake(OR=1.29), sleeping and getting up late(OR=1.26), and pungent food intake(OR=1.21), respectively. Regardless of the interaction among lifestyle-behavioral factors, the results of the multiple logistic regression analysis revealed that the risk factors of phlegm-wetness type were sleeping early and getting up late(OR=1.94), fatty food intake(OR=1.80), tobacco smoking(OR=1.50),sleeping erratically(OR=1.50), barbecued food intake(OR=1.40), sleeping and getting up late(OR=1.40), less physical activities(OR=1.31), sleeping late and getting up early(OR=1.27),and sweet food intake(OR=1.27), respectively, and the risk ofphlegm-wetness type still decreased significantly inlightfoodintake(OR=0.79).CONCLUSION: Light diet can decrease the risk of being phlegm-wetness constitution, and bad lifestyle behaviors such as sleeping early and getting up late, sleeping erratically, fatty food, barbecued food or sweet food intake, tobacco and liquor consumptions, and less physical activities can increase the risks of becoming phlegm-wetness constitution.
基金supported by the merge funding 2016e17, the Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicinesupported by the Harrington Physician Scientist Pathway at University Hospitals Cleveland Medical Centerthe Clinical Translational Science Training Program TL1 grant at Case Western Reserve University
文摘Sebaceous carcinoma (SC) of the eyelid is a rare but aggressive malignancy, accounting for 3%—5% of eyelid malignancies in the United States, and up to 35% in Asian populations (Deprez and Uffer, 2009;Xu et al., 2018;Yu et al., 2018). It is frequently mistaken for benign conditions or less aggressive malignancies such as basal cell carcinoma (Muqit et al., 2013), and the effects of delay in diagnosis can be devastating to patients. Aggressive surgical resection is the primary treatment of these tumors and often invoIves orbital exenteration with significant morbidity to patients, and these tumors frequently recur, with local recurrence rate as high as 18%. Importantly, this disease has a high metastatic potential, and there are very limited data guiding systemic treatment options;ultimately 6%—18% of patients diagnosed with SC of the eyelid succumb to metastatic disease (Zurcher et al., 1998;Shields et al., 2004).
基金supported by the National Natural Science Foundation of China(Grant Numbers 41907234 and 41907237)the Natural Science Foundation of Shaanxi Province(Grant Number 2017JQ4010 and 2018JQ4041)+1 种基金the Postdoctoral Research Foundation of China(Grant Number 2017M613033)the Fundamental Research Funds for the Central Universities,(Grant Numbers 300102210215,300102210210,300102219107 and 300102219104)。
文摘On 4 April 2013,a 1.5 million cubic meter landslide occurred in Sunjia Town,Wanzhou County,Three Gorges Reservoir,China.After initiation,the Sunjia landslide traveled about 30 m toward the northeast and destroyed most of the infrastructure in its path.The landslide was triggered by heavy rainfall and previous slope excavations,but this slope also displayed a complicated failure process:the overlying earth slope first deformed and then induced sliding along underlying rock surfaces.Surface displacements that resulted from continuous creeping of the post-event slope were observed by an emergency monitoring system that revealed the disequilibrium state of the slope.To discuss the stability and future movements of the remaining unstable debris deposits,we developed a geotechnical model of the post-slide slope,calculated how it can slide again in an extreme rainfall scenario,and estimated the potential runout distance using the Tsunami Squares method.We then estimated the number of people and the value of the infrastructure threatened by this potential landslide.Lastly,we analyzed the vulnerability of elements at risk and quantitatively evaluated the hazard risk associated with the most dangerous scenario.This quantitative risk analysis provides a better understanding of,and technical routes for,hazard mitigation of rainfallinduced complex landslides.
基金Supported by a Grant from the Major State Basic Research Development Program of China(973 Program)(No.2011CB505403)
文摘OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sample of 8448subjects from nine provinces and municipalities was chosen from the database of the TCM constitution and health status survey.Constituent ratio and correspondence analysis were used to find the relationship between smoking and drinking and TCM constitution.RESULTS:There was an association between smokinganddrinkingandtheGentleness,phlegm-dampness,and dampness-heat type constitutions.People that did not smoke tobacco or drink alcohol tended to have Yang-deficiency,Yin-deficiency,Qi-depression,Qi-deficiency,special diathesis,orblood-stasis type constitutions.CONCLUSION:There was a significant correlation between tobacco and alcohol use and TCM constitutions.To improve patient health,more attention should be paid to tobacco and alcohol control.
基金financial support from the National Natural Science Foundation of China(Nos.61871012,62022012,U1833125,U2033215)the National Key Research and Development Program of China(Nos.2020YFB0505602,2018YFB0505105)+2 种基金the Civil Aviation Security Capacity Building Fund Project,China(Nos.CAAC Contract 2020(123),CAAC Contract 2021(77))Open Fund Project of Intelligent Operation Key Laboratory of Civil Aviation Airport Group,China(No.KLAGIO20180405)the Beijing Nova Program of Science and Technology,China(No.Z191100001119134)。
文摘Dual-Frequency Ground-Based Augmentation Systems(GBAS)can be affected by receiver Inter-Frequency Bias(IFB)when Ionosphere-Free(Ifree)smoothing is applied.In the framework of the proposed GBAS Approach Service Type F(GAST-F),the IFB in the Ifree smoothed pseudorange can be corrected.However,IFB residual uncertainty still exists,which may threaten the integrity of the system.This paper presents an improved algorithm for the airborne protection level considering the residual uncertainty of IFBs to protect the integrity of dual-frequency GBAS.The IFB residual uncertainty multiplied by a frequency factor is included in the Ifree protection level together with the uncertainty of other error sources.To verify the proposed protection level algorithm,we calculate the IFB residual uncertainties of ground reference receivers and user receiver based on BDS B1I and B3I dual-frequency observation data and carry out a test at the Dongying Airport GBAS station.The results show that the proposed Ifree protection level with IFB residual uncertainty is 1.48 times the current protection level on average.The probability of Misleading Information(MI)during the test is reduced from 3.2×10^(-4)to the required value.It is proven that the proposed protection level can significantly reduce the integrity risk brought by IFB residual uncertainty and protect the integrity of dual-frequency GBAS.
基金financial support from National Key Research and Development Program of China(No.2017YFB0503404)the National Natural Science Foundation of China(Nos.61871012,U1833125)+2 种基金Open fund project of Intelligent Operation Key Laboratory of Civil Aviation Airport Group(No.KLAGIO20180405)The National Key Research and Development Program of China(No.2018YFB0505105)Beijing Nova Program of Science and Technology(No.Z191100001119134)。
文摘Detecting and characterizing Total Electron Content(TEC)depletion is important for studying the ionospheric threat due to the Equatorial Plasma Bubble(EPB)when applying the Ground-Based Augmentation System(GBAS)at low latitudes.This paper develops a robust method to automatically identify TEC depletion and derive its parameters.The rolling barrel algorithm is used to automatically identify the TEC depletion candidate and its parameters.Then,the depletion candidates are screened by several improved techniques to distinguish actual depletions from other phenomena such as Traveling Ionospheric Disturbance(TID)or abnormal data.Next,based on the depletion signals from three triangular receivers,the method derives EPB parameters such as velocity,width and gradient.The time lag and front velocity are calculated based on crosscorrelation using TEC depletions and the geometrical distribution of three triangular receivers.The width and gradient of slope are then determined by using TEC depletion from a single receiver.By comparison,both the station-pair method and proposed method depend on the assumption that the EPB morphology is frozen during the short time when the plasma bubble moves between the receivers.However,our method relaxes the restriction that the baseline length should be shorter than the width of slope required by the station-pair.This relaxation is favorable for studying small-scale slope of depletions using stations of a longer baseline.In addition,the accuracy of the width and gradient is free of impact from hardware biases and small-scale disturbance,as it is based only on the relative TEC variation.The method is demonstrated by processing Global Positioning System(GPS)and Bei Dou Navigation Satellite System(BDS)data on 15 August,2018,in a solar minimum cycle.