A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 TH...A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 THz to 1.87 THz,from 3.04 THz to 3.33 THz,from 4.17 THz to 4.48 THz,from 4.78 THz to 4.97 THz,from 5.125 THz to 5.168 THz,from5.44 THz to 5.97 THz,and from 6.74 THz to 7.01 THz.The dual-Stokes wavelengths resonance phenomena were observed in some certain tuning angle ranges.Through the theoretical analysis of the dispersion curve of the KTP crystal,the intermittent THz wave tuning range and dual-wavelength Stokes waves operation during angle tuning process were explained.The theoretical analysis was in good agreement with the experiment results.The maximum THz output voltage detected by Golay cell was 1.7 V at 5.7 THz under the pump energy of 210 mJ,corresponding to the THz wave output energy of5.47μJ and conversion efficiency of 2.6×10^(-5).展开更多
Geographic information science(GIScience)and remote sensing have long provided essential data and method-ological support for natural resource challenges and environmental problems research.With increasing advances in...Geographic information science(GIScience)and remote sensing have long provided essential data and method-ological support for natural resource challenges and environmental problems research.With increasing advances in information technology,natural resource and environmental science research faces the dual challenges of data and computational intensiveness.Therefore,the role of remote sensing and GIScience in the fields of natural resources and environmental science in this new information era is a key concern of researchers.This study clarifies the definition and frameworks of these two disciplines and discusses their role in natural resource and environmental research.GIScience is the discipline that studies the abstract and formal expressions of the basic concepts and laws of geography,and its research framework mainly consists of geo-modeling,geo-analysis,and geo-computation.Remote sensing is a comprehensive technology that deals with the mechanisms of human ef-fects on the natural ecological environment system by observing the earth surface system.Its main areas include sensors and platforms,information processing and interpretation,and natural resource and environmental appli-cations.GIScience and remote sensing provide data and methodological support for resource and environmental science research.They play essential roles in promoting the development of resource and environmental science and other related technologies.This paper provides forecasts of ten future directions for GIScience and eight future directions for remote sensing,which aim to solve issues related to natural resources and the environment.展开更多
Distinguishing between nonalcoholic steatohepatitis(NASH) and advanced liver fibrosis is the key for clinical diagnosis of non-alcoholic fatty liver disease(NAFLD). Liver biopsy, which is widely used for diagnosis of ...Distinguishing between nonalcoholic steatohepatitis(NASH) and advanced liver fibrosis is the key for clinical diagnosis of non-alcoholic fatty liver disease(NAFLD). Liver biopsy, which is widely used for diagnosis of liver diseases at present, has many drawbacks, such as being invasive, expensive and unstable. This article compares and summarizes the commonly used non-invasive diagnostic methods, including their diagnostic parameters, advantages and disadvantages, in order to provide a useful reference for the diagnosis of NASH.展开更多
Background and Aims:Age-related mosaic chromosomal alterations(mCAs)detected from genotyping of blood-de-rived DNA are structural somatic variants that indicate clonal hematopoiesis.This study aimed to investigate whe...Background and Aims:Age-related mosaic chromosomal alterations(mCAs)detected from genotyping of blood-de-rived DNA are structural somatic variants that indicate clonal hematopoiesis.This study aimed to investigate whether mCAs contribute to the risk of cirrhosis and modify the effect of a polygenic risk score(PRS)on cirrhosis risk prediction.Methods:mCA call sets of individuals with European ancestry were obtained from the UK Biobank.The PRS was constructed based on 12 susceptible single-nucleotide poly-morphisms for cirrhosis.Cox proportional hazard models were applied to evaluate the associations between mCAs and cirrhosis risk.Results:Among 448,645 individuals with a median follow-up of 12.5 years,we identified 2,681 cas-es of cirrhosis,1,775 cases of compensated cirrhosis,and 1,706 cases of decompensated cirrhosis.Compared to non-carriers,individuals with copy-neutral loss of heterozygosity mCAs had a significantly increased risk of cirrhosis(hazard ratio(HR)1.42,95%confidence interval(CI)1.12-1.81).This risk was higher in patients with expanded cell fractions of mCAs(cell fractions≥10%vs.cell fractions<10%),especially for the risk of decompensated cirrhosis(HR 2.03[95%CI 1.09-3.78]vs.1.14[0.80-1.64]).In comparison to non-carriers of mCAs with low genetic risk,individuals with expanded copy-neutral loss of heterozygosity and high genetic risk showed the highest cirrhosis risk(HR5.39[95%CI 2.41-12.07]).Conclusions:The presence of mCAs is associated with increased susceptibility to cirrhosis risk and could be combined with PRS for personalized cirrhosis risk stratification.展开更多
Nonalcoholic fatty liver disease(NAFLD)is the most common chronic liver disease with an estimated worldwide prevalence of 32.4%.1 The multisystem condition is related to an increased risk of liver-related and cardiova...Nonalcoholic fatty liver disease(NAFLD)is the most common chronic liver disease with an estimated worldwide prevalence of 32.4%.1 The multisystem condition is related to an increased risk of liver-related and cardiovascular extrahepatic diseases.2 Smoking is the leading preventable risk factor for premature disability and mortality.As NAFLD and smoking are both associated with the development of metabolic features,there has been increasing interest in testing the relationship between smoking and NAFLD.The causal relevance of smoking to NAFLD incidence have been implicated in crosssectional and prospective cohort studies.3,4 However,previous studies mainly focused on the effect of active smoking,discussion on the influence of passive smoking on NAFLD will facilitate illustrating the association between smoking and NAFLD.We conducted a national two-center cross-section study of active,passive smoking and NAFLD risk in Chinese and European population.This design allowed us to(1)test for associations between active,passive smoking and NAFLD risk by sex and consolidate evidence for causality by estimating dose-response relationship,(2)identify mediated factors,and(3)resolve their possible interaction with smoking.展开更多
第5代移动通信技术(5th generation mobile networks,5G通信)发展方兴未艾。5G网络的普及需要建设大量的5G基站,这些海量的5G基站将在未来成为可观的潜在灵活性资源。5G基站参与需求响应,即对于5G基站中的供电设备和用电设备进行调度,...第5代移动通信技术(5th generation mobile networks,5G通信)发展方兴未艾。5G网络的普及需要建设大量的5G基站,这些海量的5G基站将在未来成为可观的潜在灵活性资源。5G基站参与需求响应,即对于5G基站中的供电设备和用电设备进行调度,能够在降低5G用电成本的同时,为电力系统提供灵活性资源,实现通信系统与电力系统的双赢。该文总结了5G基站的基本组成设备和用电特性,分析了其参与需求响应的潜力;梳理了5G基站参与需求响应所必需的关键技术;展望了5G基站作为需求侧资源参与电力系统互动的应用场景;最后,对于5G基站参与需求响应潜在的商业模式进行探讨。展开更多
随着大规模储能系统的广泛发展,快速准确地估计锂离子电池的荷电状态(state of charge,SOC)对系统的安全可靠运行至关重要。然而,在传统的固定串并联电池单元/模块拓扑结构中,无法直接测量电池单元/模块的开路电压(open circuit voltage...随着大规模储能系统的广泛发展,快速准确地估计锂离子电池的荷电状态(state of charge,SOC)对系统的安全可靠运行至关重要。然而,在传统的固定串并联电池单元/模块拓扑结构中,无法直接测量电池单元/模块的开路电压(open circuit voltage,OCV),也就无法建立OCV-SOC映射关系来准确估计SOC。对此,提出一种基于新型动态可重构电池网络的精准SOC估计方法。该方法可以在1s内测量得到OCV,然后使用梯度增强决策树估计电池单元/模块的准确SOC。实验结果表明该方法的高效率和有效性,为电池状态估计提供了一个范式结构。展开更多
The outbreak of the 2019 novel coronavirus disease(COVID-19)has caused more than 100,000 people infected and thousands of deaths.Currently,the number of infections and deaths is still increasing rapidly.COVID-19 serio...The outbreak of the 2019 novel coronavirus disease(COVID-19)has caused more than 100,000 people infected and thousands of deaths.Currently,the number of infections and deaths is still increasing rapidly.COVID-19 seriously threatens human health,production,life,social functioning and international relations.In the fight against COVID-19,Geographic Information Systems(GIS)and big data technologies have played an important role in many aspects,including the rapid aggregation of multi-source big data,rapid visualization of epidemic information,spatial tracking of confirmed cases,prediction of regional transmission,spatial segmentation of the epidemic risk and prevention level,balancing and management of the supply and demand of material resources,and socialemotional guidance and panic elimination,which provided solid spatial information support for decision-making,measures formulation,and effectiveness assessment of COVID-19 prevention and control.GIS has developed and matured relatively quickly and has a complete technological route for data preparation,platform construction,model construction,and map production.However,for the struggle against the widespread epidemic,the main challenge is finding strategies to adjust traditional technical methods and improve speed and accuracy of information provision for social management.At the data level,in the era of big data,data no longer come mainly from the government but are gathered from more diverse enterprises.As a result,the use of GIS faces difficulties in data acquisition and the integration of heterogeneous data,which requires governments,businesses,and academic institutions to jointly promote the formulation of relevant policies.At the technical level,spatial analysis methods for big data are in the ascendancy.Currently and for a long time in the future,the development of GIS should be strengthened to form a data-driven system for rapid knowledge acquisition,which signifies ts that GIS should be used to reinforce the social operation parameterization of models and methods,especially when providing support for social management.展开更多
Accurate estimates of forest aboveground biomass(AGB)are critical for supporting strategies of ecosystem conservation and climate change mitigation.The Jiuzhaigou National Nature Reserve,located in Eastern Tibet Plate...Accurate estimates of forest aboveground biomass(AGB)are critical for supporting strategies of ecosystem conservation and climate change mitigation.The Jiuzhaigou National Nature Reserve,located in Eastern Tibet Plateau,has rich forest resources on steep slopes and is very sensitive to climate change but plays an important role in the regulation of regional carbon cycles.However,an estimation of AGB of subalpine forests in the Nature Reserve has not been carried out and whether a global biomass model is available has not been determined.To provide this information,Landsat 8 OLI and Sentinel-2B data were combined to estimate subalpine forest AGB using linear regression,and two machine learning approaches–random forest and extreme gradient boosting,with 54 inventory plots.Regardless of forest type,Observed AGB of the Reserve varied from 61.7 to 475.1 Mg hawith an average of 180.6 Mg ha.Results indicate that integrating the Landsat 8 OLI and Sentinel-2B imagery significantly improved model efficiency regardless of modelling approaches.The results highlight a potential way to improve the prediction of forest AGB in mountainous regions.Modelled AGB indicated a strong spatial variability.However,the modelled biomass varied greatly with global biomass products,indicating that global biomass products should be evaluated in regional AGB estimates and more field observations are required,particularly for areas with complex terrain to improve model accuracy.展开更多
基金Project supported by the National Basic Research Program of China(Grant Nos.2015CB755403 and 2014CB339802)the National Key Research and Development Program of China(Grant No.2016YFC0101001)+2 种基金the National Natural Science Foundation of China(Grant Nos.61775160,61771332,and 61471257)China Postdoctoral Science Foundation(Grant No.2016M602954)Postdoctoral Science Foundation of Chongqing,China(Grant No.Xm2016021)
文摘A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 THz to 1.87 THz,from 3.04 THz to 3.33 THz,from 4.17 THz to 4.48 THz,from 4.78 THz to 4.97 THz,from 5.125 THz to 5.168 THz,from5.44 THz to 5.97 THz,and from 6.74 THz to 7.01 THz.The dual-Stokes wavelengths resonance phenomena were observed in some certain tuning angle ranges.Through the theoretical analysis of the dispersion curve of the KTP crystal,the intermittent THz wave tuning range and dual-wavelength Stokes waves operation during angle tuning process were explained.The theoretical analysis was in good agreement with the experiment results.The maximum THz output voltage detected by Golay cell was 1.7 V at 5.7 THz under the pump energy of 210 mJ,corresponding to the THz wave output energy of5.47μJ and conversion efficiency of 2.6×10^(-5).
基金This work was supported by the National Natural Science Foundation of China(Grant No.L1924041,41525004)the Research Project on the Discipline Development Strategy of Academic Divisions of the Chinese Academy of Sciences(Grant No.XK2019DXC006).
文摘Geographic information science(GIScience)and remote sensing have long provided essential data and method-ological support for natural resource challenges and environmental problems research.With increasing advances in information technology,natural resource and environmental science research faces the dual challenges of data and computational intensiveness.Therefore,the role of remote sensing and GIScience in the fields of natural resources and environmental science in this new information era is a key concern of researchers.This study clarifies the definition and frameworks of these two disciplines and discusses their role in natural resource and environmental research.GIScience is the discipline that studies the abstract and formal expressions of the basic concepts and laws of geography,and its research framework mainly consists of geo-modeling,geo-analysis,and geo-computation.Remote sensing is a comprehensive technology that deals with the mechanisms of human ef-fects on the natural ecological environment system by observing the earth surface system.Its main areas include sensors and platforms,information processing and interpretation,and natural resource and environmental appli-cations.GIScience and remote sensing provide data and methodological support for resource and environmental science research.They play essential roles in promoting the development of resource and environmental science and other related technologies.This paper provides forecasts of ten future directions for GIScience and eight future directions for remote sensing,which aim to solve issues related to natural resources and the environment.
基金Supported by Traditional Chinese Medicine Development Program of Shandong Province (2021Q097)。
文摘Distinguishing between nonalcoholic steatohepatitis(NASH) and advanced liver fibrosis is the key for clinical diagnosis of non-alcoholic fatty liver disease(NAFLD). Liver biopsy, which is widely used for diagnosis of liver diseases at present, has many drawbacks, such as being invasive, expensive and unstable. This article compares and summarizes the commonly used non-invasive diagnostic methods, including their diagnostic parameters, advantages and disadvantages, in order to provide a useful reference for the diagnosis of NASH.
基金supported by the Jiangsu Province Capability Improvement Project through Science,Technology and Education(grant number:ZDXK202248,recipient:QZ)National Natural Science Foundation of China(grant number:82373654,recipient:CS)+2 种基金Science and Technology Young Scientific and Technological Talents Project of Jiangsu Province(grant number:2021-50,recipient:CS)Key project of Changzhou Medical Center,Nanjing Medical University(grant number:CZKYCMCM202210,recipient:CS)Chinese Academy of Medical Sciences(grant number:2019RU038,recipient:CS).
文摘Background and Aims:Age-related mosaic chromosomal alterations(mCAs)detected from genotyping of blood-de-rived DNA are structural somatic variants that indicate clonal hematopoiesis.This study aimed to investigate whether mCAs contribute to the risk of cirrhosis and modify the effect of a polygenic risk score(PRS)on cirrhosis risk prediction.Methods:mCA call sets of individuals with European ancestry were obtained from the UK Biobank.The PRS was constructed based on 12 susceptible single-nucleotide poly-morphisms for cirrhosis.Cox proportional hazard models were applied to evaluate the associations between mCAs and cirrhosis risk.Results:Among 448,645 individuals with a median follow-up of 12.5 years,we identified 2,681 cas-es of cirrhosis,1,775 cases of compensated cirrhosis,and 1,706 cases of decompensated cirrhosis.Compared to non-carriers,individuals with copy-neutral loss of heterozygosity mCAs had a significantly increased risk of cirrhosis(hazard ratio(HR)1.42,95%confidence interval(CI)1.12-1.81).This risk was higher in patients with expanded cell fractions of mCAs(cell fractions≥10%vs.cell fractions<10%),especially for the risk of decompensated cirrhosis(HR 2.03[95%CI 1.09-3.78]vs.1.14[0.80-1.64]).In comparison to non-carriers of mCAs with low genetic risk,individuals with expanded copy-neutral loss of heterozygosity and high genetic risk showed the highest cirrhosis risk(HR5.39[95%CI 2.41-12.07]).Conclusions:The presence of mCAs is associated with increased susceptibility to cirrhosis risk and could be combined with PRS for personalized cirrhosis risk stratification.
基金supported by the National Natural Science Foundation of China(No.81903382)Natural Science Foundation of Jiangsu Province(Nos.BK20190652,BK20220320)+2 种基金Science and Technology Young Scientific and Technological Talents Project of Jiangsu Province(No.2021-50)China Postdoctoral Science Foundation(Nos.General Program,2019M651900,2021M701757)CAMS Innovation Fund for Medical Sciences(No.2019RU038).
文摘Nonalcoholic fatty liver disease(NAFLD)is the most common chronic liver disease with an estimated worldwide prevalence of 32.4%.1 The multisystem condition is related to an increased risk of liver-related and cardiovascular extrahepatic diseases.2 Smoking is the leading preventable risk factor for premature disability and mortality.As NAFLD and smoking are both associated with the development of metabolic features,there has been increasing interest in testing the relationship between smoking and NAFLD.The causal relevance of smoking to NAFLD incidence have been implicated in crosssectional and prospective cohort studies.3,4 However,previous studies mainly focused on the effect of active smoking,discussion on the influence of passive smoking on NAFLD will facilitate illustrating the association between smoking and NAFLD.We conducted a national two-center cross-section study of active,passive smoking and NAFLD risk in Chinese and European population.This design allowed us to(1)test for associations between active,passive smoking and NAFLD risk by sex and consolidate evidence for causality by estimating dose-response relationship,(2)identify mediated factors,and(3)resolve their possible interaction with smoking.
文摘第5代移动通信技术(5th generation mobile networks,5G通信)发展方兴未艾。5G网络的普及需要建设大量的5G基站,这些海量的5G基站将在未来成为可观的潜在灵活性资源。5G基站参与需求响应,即对于5G基站中的供电设备和用电设备进行调度,能够在降低5G用电成本的同时,为电力系统提供灵活性资源,实现通信系统与电力系统的双赢。该文总结了5G基站的基本组成设备和用电特性,分析了其参与需求响应的潜力;梳理了5G基站参与需求响应所必需的关键技术;展望了5G基站作为需求侧资源参与电力系统互动的应用场景;最后,对于5G基站参与需求响应潜在的商业模式进行探讨。
文摘随着大规模储能系统的广泛发展,快速准确地估计锂离子电池的荷电状态(state of charge,SOC)对系统的安全可靠运行至关重要。然而,在传统的固定串并联电池单元/模块拓扑结构中,无法直接测量电池单元/模块的开路电压(open circuit voltage,OCV),也就无法建立OCV-SOC映射关系来准确估计SOC。对此,提出一种基于新型动态可重构电池网络的精准SOC估计方法。该方法可以在1s内测量得到OCV,然后使用梯度增强决策树估计电池单元/模块的准确SOC。实验结果表明该方法的高效率和有效性,为电池状态估计提供了一个范式结构。
基金funded by the National Natural Science Foundation of China(41421001,42041001 and 41525004).
文摘The outbreak of the 2019 novel coronavirus disease(COVID-19)has caused more than 100,000 people infected and thousands of deaths.Currently,the number of infections and deaths is still increasing rapidly.COVID-19 seriously threatens human health,production,life,social functioning and international relations.In the fight against COVID-19,Geographic Information Systems(GIS)and big data technologies have played an important role in many aspects,including the rapid aggregation of multi-source big data,rapid visualization of epidemic information,spatial tracking of confirmed cases,prediction of regional transmission,spatial segmentation of the epidemic risk and prevention level,balancing and management of the supply and demand of material resources,and socialemotional guidance and panic elimination,which provided solid spatial information support for decision-making,measures formulation,and effectiveness assessment of COVID-19 prevention and control.GIS has developed and matured relatively quickly and has a complete technological route for data preparation,platform construction,model construction,and map production.However,for the struggle against the widespread epidemic,the main challenge is finding strategies to adjust traditional technical methods and improve speed and accuracy of information provision for social management.At the data level,in the era of big data,data no longer come mainly from the government but are gathered from more diverse enterprises.As a result,the use of GIS faces difficulties in data acquisition and the integration of heterogeneous data,which requires governments,businesses,and academic institutions to jointly promote the formulation of relevant policies.At the technical level,spatial analysis methods for big data are in the ascendancy.Currently and for a long time in the future,the development of GIS should be strengthened to form a data-driven system for rapid knowledge acquisition,which signifies ts that GIS should be used to reinforce the social operation parameterization of models and methods,especially when providing support for social management.
基金supported financially by the Specialized Fund for the Post-Disaster Reconstruction and Heritage Protec-tion in Sichuan Province(5132202019000128)the Everest Scientific Research Program of Chengdu University of Technology(80000-2021ZF11410)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,2019QZKK0307)the State Key Laborato-ry of Geohazard Prevention and Geoenvironment Protection Independent Research Project(SKLGP2018Z004)the key technologies of Mountain rail transit green construction in ecologically sensitive region based on Mountain rail transit from Dujiangyan to Mt.Siguniang anti-poverty project(2018-zl-08)Study on risk identification and countermeasures of Sichuan-Tibet Railway Major Projects(2019YFG0460)。
文摘Accurate estimates of forest aboveground biomass(AGB)are critical for supporting strategies of ecosystem conservation and climate change mitigation.The Jiuzhaigou National Nature Reserve,located in Eastern Tibet Plateau,has rich forest resources on steep slopes and is very sensitive to climate change but plays an important role in the regulation of regional carbon cycles.However,an estimation of AGB of subalpine forests in the Nature Reserve has not been carried out and whether a global biomass model is available has not been determined.To provide this information,Landsat 8 OLI and Sentinel-2B data were combined to estimate subalpine forest AGB using linear regression,and two machine learning approaches–random forest and extreme gradient boosting,with 54 inventory plots.Regardless of forest type,Observed AGB of the Reserve varied from 61.7 to 475.1 Mg hawith an average of 180.6 Mg ha.Results indicate that integrating the Landsat 8 OLI and Sentinel-2B imagery significantly improved model efficiency regardless of modelling approaches.The results highlight a potential way to improve the prediction of forest AGB in mountainous regions.Modelled AGB indicated a strong spatial variability.However,the modelled biomass varied greatly with global biomass products,indicating that global biomass products should be evaluated in regional AGB estimates and more field observations are required,particularly for areas with complex terrain to improve model accuracy.
