This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate ...This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.展开更多
Background:Current guidelines for managing pulmonary arterial hypertension(PAH)recommend a risk strati-fication approach.However,the applicability and accuracy of these strategies for PAH associated with congenital he...Background:Current guidelines for managing pulmonary arterial hypertension(PAH)recommend a risk strati-fication approach.However,the applicability and accuracy of these strategies for PAH associated with congenital heart disease(PAH-CHD)require further validation.This study aims to validate the reliability and predictive accuracy of a simplified stratification strategy for PAH-CHD patients over a three-year follow-up.Additionally,new prognostic variables are identified and novel risk stratification methods are developed for assessing and managing PAH-CHD patients.Methods:This retrospective study included 126 PAH-CHD patients.Clinical and biochemical variables across risk groups were assessed using Kruskal-Wallis and Fisher’s exact tests.Indepen-dent risk factors were identified using ordered logistic regression,while Kaplan-Meier and Cox proportional hazards regression analyses evaluated their impact on all-cause mortality.A new stratification model for the PAH-CHD population was constructed based on these analyses.Results:Significant survival differences across stratified risk groups were observed(p<0.001),validating the effectiveness of the simplified risk stratification method in PAH-CHD patients.Prothrombin activity was a strong independent predictor of adverse outcomes of PAH-CHD patients(Hazard ratio 0.95,p<0.001,C-index 0.70).A model combining N-terminal pro-brain natriuretic peptide,prothrombin activity,albumin,and right atrial area achieved an area under the curve of 0.89 and a C-index of 0.85.Conclusions:The simplified risk stratification method is applicable to PAH-CHD patients.Prothrombin activity is a strong independent predictor of adverse outcomes.A comprehensive risk stratification approach,incorporating both established and novel biomarkers,enhances accessibility and offers predictive efficacy during follow-up for PAH-CHD patients,comparable to established models.展开更多
Based on C-LSAT2.0,using high-and low-frequency components reconstruction methods,combined with observation constraint masking,a reconstructed C-LSAT2.0 with 756 ensemble members from the 1850s to 2018 has been develo...Based on C-LSAT2.0,using high-and low-frequency components reconstruction methods,combined with observation constraint masking,a reconstructed C-LSAT2.0 with 756 ensemble members from the 1850s to 2018 has been developed.These ensemble versions have been merged with the ERSSTv5 ensemble dataset,and an upgraded version of the CMSTInterim dataset with 5°×5°resolution has been developed.The CMST-Interim dataset has significantly improved the coverage rate of global surface temperature data.After reconstruction,the data coverage before 1950 increased from 78%−81%of the original CMST to 81%−89%.The total coverage after 1955 reached about 93%,including more than 98%in the Northern Hemisphere and 81%−89%in the Southern Hemisphere.Through the reconstruction ensemble experiments with different parameters,a good basis is provided for more systematic uncertainty assessment of C-LSAT2.0 and CMSTInterim.In comparison with the original CMST,the global mean surface temperatures are estimated to be cooler in the second half of 19th century and warmer during the 21st century,which shows that the global warming trend is further amplified.The global warming trends are updated from 0.085±0.004℃(10 yr)^(–1)and 0.128±0.006℃(10 yr)^(–1)to 0.089±0.004℃(10 yr)^(–1)and 0.137±0.007℃(10 yr)^(–1),respectively,since the start and the second half of 20th century.展开更多
A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameteriza...A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.展开更多
In this paper, a variation series of snow cover and seasonal freeze-thaw layer from 1965 to 2004 on the Tibetan Plateau has been established by using the observation data from meteorological stations. The sliding T-te...In this paper, a variation series of snow cover and seasonal freeze-thaw layer from 1965 to 2004 on the Tibetan Plateau has been established by using the observation data from meteorological stations. The sliding T-test, M-K test and B-G algorithm are used to verify abrupt changes of snow cover and seasonal freeze-thaw layer in the Tibetan plateau. The results show that the snow cover has not undergone an abrupt change, but the seasonal freeze-thaw layer obviously witnessed a rapid degradation in 1987, with the frozen soil depth being reduced by about 15 cm. It is also found that when there ~s less snow in the plateau region, precipitation in South China and Southwest China increases. But when the frozen soil is deep, precipitation in most of China apparently decreases. Both snow cover and seasonal freeze-thaw layer on the plateau can be used to predict the summer precipitation in China. However, if the impacts of snow cover and seasonal freeze-thaw layer are used at the same time, the predictability of summer precipitation can be significantly improved. The significant correlation zone of snow is located in middle reaches of the Yangtze River covering the Hexi Corridor and northeastern Inner Mongolia, and the seasonal freeze-thaw layer exists in Mt. Nanling, northern Shannxi and northwestern part of North China. The significant correlation zone of simultaneous impacts of snow cover and seasonal freeze-thaw layer is larger than that of either snow cover or seasonal freeze-thaw layer. There are three significant correlation zones extending from north to south： the north zone spreads from Mr. Daxinganling to the Hexi Corridor, crossing northern Mt. Taihang and northern Shannxi; the central zone covers middle and lower reaches of the Yangtze River; and the south zone extends from Mt. Wuyi to Yunnan and Guizhou Plateau through Mt. Nanling.展开更多
One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of ＂common but differentiated responsibilities＂. This formul...One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of ＂common but differentiated responsibilities＂. This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model（CESM）, we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases（GHGs）in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century.展开更多
This is a letter from two Chinese scientists to Dr. Dahe Qin, Co-Chair of IPCC Working Group 1. Human society has taken an historical step to address climate change issue. However, how to understand climate change and...This is a letter from two Chinese scientists to Dr. Dahe Qin, Co-Chair of IPCC Working Group 1. Human society has taken an historical step to address climate change issue. However, how to understand climate change and how to response to climate change will always and everywhere lead various types of disagreements and disputes, thus affecting the pace of societies＇ promptly taking orderly human activity against climate change. In the letter, the two scientists bring up their thoughts and recommendations on how to carry out coordinated research on orderly human activity to cope with global climate change.展开更多
This paper presents an analysis of the mechanisms and impacts of snow cover and frozen soil in the Tibetan Plateau on the sum- mer precipitation in China, using RegCM3 version 3.1 model simulations. Comparisons of sim...This paper presents an analysis of the mechanisms and impacts of snow cover and frozen soil in the Tibetan Plateau on the sum- mer precipitation in China, using RegCM3 version 3.1 model simulations. Comparisons of simulations vs. observations show that RegCM3 well captures these impacts. Results indicate that in a more-snow year with deep frozen soil there will be more precipita- tion in the Yangtze River Basin and central Northwest China, western Inner Mongolia, and Xinjiang, but less precipitation in Northeast China, North China, South China, and most of Southwest China. In a less-snow year with deep frozen soil, however, there will be more precipitation in Northeast China, North China, and southern South China, but less precipitation in the Yangtze River Basin and in northern South China. Such differences may be attributed to different combination patterns of melting snow and thawing frozen soil on the Plateau, which may change soil moisture as well as cause differences in energy absorption in the phase change processes of snow cover and frozen soil. These factors may produce more surface sensible heat in more-snow years when the fi＇ozen soil is deep than when the frozen soil is shallow. The higher surface sensible heat may lead to a stronger updraft over the Plateau, eventually contributing to a stronger South Asia High and West Pacific Subtropical High. Due to different values of the wind fields at 850 hPa, a convergence zone will form over the Yangtze River Basin, which may produce more summer pre- cipitation in the basin area but less precipitation in North China and South China. However, because soil moisture depends on ice content, in less-snow years with deep frozen soil, the soil moisture will be higher. The combination of higher frozen soil moisture with latent heat absorption in the phase change process may generate less surface sensible heat and consequently a weaker updraft motion over the Plateau. As a result, both the South Asia High and the West Pacific Subtropical High will be weaker, hence caus- ing more summer precipitation in northern China but less in southem China.展开更多
The immunohistochemical(IHC)staining of the human epidermal growth factor receptor 2(HER2)biomarker is widely practiced in breast tissue analysis,preclinical studies,and diagnostic decisions,guiding cancer treatment a...The immunohistochemical(IHC)staining of the human epidermal growth factor receptor 2(HER2)biomarker is widely practiced in breast tissue analysis,preclinical studies,and diagnostic decisions,guiding cancer treatment and investigation of pathogenesis.HER2 staining demands laborious tissue treatment and chemical processing performed by a histotechnologist,which typically takes one day to prepare in a laboratory,increasing analysis time and associated costs.Here,we describe a deep learning-based virtual HER2 IHC staining method using a conditional generative adversarial network that is trained to rapidly transform autofluorescence microscopic images of unlabeled/label-free breast tissue sections into bright-field equivalent microscopic images,matching the standard HER2 IHC staining that is chemically performed on the same tissue sections.The efficacy of this virtual HER2 staining framework was demonstrated by quantitative analysis,in which three board-certified breast pathologists blindly graded the HER2 scores of virtually stained and immunohistochemically stained HER2 whole slide images(WSIs)to reveal that the HER2 scores determined by inspecting virtual IHC images are as accurate as their immunohistochemically stained counterparts.A second quantitative blinded study performed by the same diagnosticians further revealed that the virtually stained HER2 images exhibit a comparable staining quality in the level of nuclear detail,membrane clearness,and absence of staining artifacts with respect to their immunohistochemically stained counterparts.This virtual HER2 staining framework bypasses the costly,laborious,and time-consuming IHC staining procedures in laboratory and can be extended to other types of biomarkers to accelerate the IHC tissue staining used in life sciences and biomedical workflow.展开更多
Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,...Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,energy,materials,quantum,and microelectronics.Surface science mainly investigates the correspondence between surface property and functionality.Scanning probe microscopy(SPM)techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging,spectroscopy and manipulation at the single-atom level.In this review,we summarize recent advances in surface electronic,magnetic and optical properties characterized mainly by SPM-based methods.We focus on elucidating theπ-magnetism in graphene-based nanostructures,construction of spin qubits on surfaces,topology properties of surface organic structures,STM-based light emission,tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.展开更多
Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natura...Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo.Here,we found that amphipol and digitonin stabilized the structure of natural silk fibroin(NSF)by a large-scale screening in vitro,and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen.Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm,rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules.Metal ions were required for NSF nanofibril formation.The successive p H decrease from posterior silk gland(PSG)to anterior silk gland(ASG)resulted in a gradual increase in NSF hydrophobicity,thus inducing the sol-gelation transition of NSF nanofibrils.NSF nanofibrils were randomly dispersed from PSG to ASG-1,and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning.Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and p H gradient,which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers.展开更多
Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental s...Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental science and applied technology.This review will summarize the recent progresses on surface assembly,synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy.Surface assemblies of water and small biomolecules,construction of Sierpin′ski triangles and surface chirality are summarized.On-surface synthesis of conjugated carbo-and heterocycles and other kinds of carbon nanostructures are surveyed.Surface model catalysis,including single-atom catalysis and electrochemical catalysis,are discussed at the single-atom level.展开更多
Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction ...Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction between the coupled earth system models and the IAMs. This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University （BNU-ESM）. With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.展开更多
INTRODUCTION.Natural disasters,including floods,storms,and tsunamis,pose a great threat to human societies.A recent study highlighted this concern,revealing that billions of people globally were exposed to flood hazar...INTRODUCTION.Natural disasters,including floods,storms,and tsunamis,pose a great threat to human societies.A recent study highlighted this concern,revealing that billions of people globally were exposed to flood hazards.1 In 2023,Super Typhoon Doksuri caused devasting floods in Beijing and Hebei areas,resulting in massive casualties and huge economic losses.Therefore,there is a need for a precise understanding of disaster processes,reliable forecasting of disaster effects,and timely warning of risks to prevent and mitigate major disasters.2 Numerical modeling stands as the predominant approach to meet these demands.However,the predictive accuracy of such numerical models could be degraded because of various factors:oversimplification of real processes,computational errors,fluctuations of complex environments(e.g.,terrains,precipitations,buildings,and plants),and the influence of human activities(e.g.,evacuation and rescue)during disasters.展开更多
Global mean surface temperature(GMST)is one of the most important large-scale indicators for characterizing climate change on Earth,and Surface Temperature(ST)is also the most accurate key climate element currently un...Global mean surface temperature(GMST)is one of the most important large-scale indicators for characterizing climate change on Earth,and Surface Temperature(ST)is also the most accurate key climate element currently understood by scientists and the public.Even so,there have been extensive discussions about the accuracy of global(regional)surface temperature(air temperature)changes[lj.From the perspective of climatic data acquisition and data reliability,the current GMST series and the evaluation of global warming rates are all based on several observation-based datasets produced by combining anomalies of Land Surface Air Temperatures(LSAT)and Sea Surface Temperatures(SST).展开更多
The carbon cycle is one of the fundamental climate change issues.Its long-term evolution largely affects the amplitude and trend of human-induced climate change,as well as the formulation and implementation of emissio...The carbon cycle is one of the fundamental climate change issues.Its long-term evolution largely affects the amplitude and trend of human-induced climate change,as well as the formulation and implementation of emission reduction policy and technology for stabilizing the atmospheric CO2concentration.Two earth system models incorporating the global carbon cycle,the Community Earth System Model and the Beijing Normal University-Earth System Model,were used to investigate the effect of the carbon cycle on the attribution of the historical responsibility for climate change.The simulations show that when compared with the criterion based on cumulative emissions,the developed(developing)countries’responsibility is reduced(increased)by 6%–10%using atmospheric CO2concentration as the criterion.This discrepancy is attributed to the fact that the developed world contributed approximately61%–68%(61%–64%)to the change in global oceanic(terrestrial)carbon sequestration for the period from 1850 to2005,whereas the developing world contributed approximately 32%–49%(36%–39%).Under a developed world emissions scenario,the relatively larger uptake of global carbon sinks reduced the developed countries’responsibility for carbon emissions but increased their responsibility for global ocean acidification(68%).In addition,the large emissions from the developed world reduced the efficiency of the global carbon sinks,which may affect the long-term carbon sequestration and exacerbate global warming in the future.Therefore,it is necessary to further consider the interaction between carbon emissions and the carbon cycle when formulating emission reduction policy.展开更多
The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century,...The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century, near-surface air temperature changes over ~5%(~2%), ~40%(~18%), and ~92%(~86%)of the globe will cross the 1.5 ℃(2.0 ℃) threshold under RCP2.6, RCP4.5, and RCP8.5, respectively. Under RCP8.5, nearly the whole of North America, Europe + Russia, Africa, and Asia–Russia will cross the 1.5 ℃(2.0 ℃) threshold in ~2050(~2060), while the coverage rates over South America and Oceania are ~80%(~75%) and ~50%(~30%), respectively. The threshold-onset time(TOT) for 2 ℃ warming is earliest over Europe + Russia and North America, followed by Africa, Asia–Russia, South America, and finally Oceania under the RCP4.5 and RCP8.5 scenarios. The TOT for 1.5 ℃ is ~10–30 years ahead of that for 2.0 ℃.展开更多
基金funded by the National Natu-ral Science Foundation of China(Grant No.42075044 and No.41975112)a project supported by the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311022006).
文摘This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.
基金This work was supported by the National Natural Science Foundation of China(82070052)the Joint Funds of the Natural Science Foundation of Gansu Province(23JRRA1544)granted to Yunshan Cao.
文摘Background:Current guidelines for managing pulmonary arterial hypertension(PAH)recommend a risk strati-fication approach.However,the applicability and accuracy of these strategies for PAH associated with congenital heart disease(PAH-CHD)require further validation.This study aims to validate the reliability and predictive accuracy of a simplified stratification strategy for PAH-CHD patients over a three-year follow-up.Additionally,new prognostic variables are identified and novel risk stratification methods are developed for assessing and managing PAH-CHD patients.Methods:This retrospective study included 126 PAH-CHD patients.Clinical and biochemical variables across risk groups were assessed using Kruskal-Wallis and Fisher’s exact tests.Indepen-dent risk factors were identified using ordered logistic regression,while Kaplan-Meier and Cox proportional hazards regression analyses evaluated their impact on all-cause mortality.A new stratification model for the PAH-CHD population was constructed based on these analyses.Results:Significant survival differences across stratified risk groups were observed(p<0.001),validating the effectiveness of the simplified risk stratification method in PAH-CHD patients.Prothrombin activity was a strong independent predictor of adverse outcomes of PAH-CHD patients(Hazard ratio 0.95,p<0.001,C-index 0.70).A model combining N-terminal pro-brain natriuretic peptide,prothrombin activity,albumin,and right atrial area achieved an area under the curve of 0.89 and a C-index of 0.85.Conclusions:The simplified risk stratification method is applicable to PAH-CHD patients.Prothrombin activity is a strong independent predictor of adverse outcomes.A comprehensive risk stratification approach,incorporating both established and novel biomarkers,enhances accessibility and offers predictive efficacy during follow-up for PAH-CHD patients,comparable to established models.
文摘Based on C-LSAT2.0,using high-and low-frequency components reconstruction methods,combined with observation constraint masking,a reconstructed C-LSAT2.0 with 756 ensemble members from the 1850s to 2018 has been developed.These ensemble versions have been merged with the ERSSTv5 ensemble dataset,and an upgraded version of the CMSTInterim dataset with 5°×5°resolution has been developed.The CMST-Interim dataset has significantly improved the coverage rate of global surface temperature data.After reconstruction,the data coverage before 1950 increased from 78%−81%of the original CMST to 81%−89%.The total coverage after 1955 reached about 93%,including more than 98%in the Northern Hemisphere and 81%−89%in the Southern Hemisphere.Through the reconstruction ensemble experiments with different parameters,a good basis is provided for more systematic uncertainty assessment of C-LSAT2.0 and CMSTInterim.In comparison with the original CMST,the global mean surface temperatures are estimated to be cooler in the second half of 19th century and warmer during the 21st century,which shows that the global warming trend is further amplified.The global warming trends are updated from 0.085±0.004℃(10 yr)^(–1)and 0.128±0.006℃(10 yr)^(–1)to 0.089±0.004℃(10 yr)^(–1)and 0.137±0.007℃(10 yr)^(–1),respectively,since the start and the second half of 20th century.
基金supported by Chinese National Science Foundation (NSFC) (No.40875050, 40575037, 40175020)National Key Basic Science Studies Developing Program of "973" (2007CB411506)
文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.
基金by the National Key Basic Research Program(2007CB411505)S&T Support Project(2007BAC29B06)National Natural Science Foundation(40705031)
文摘In this paper, a variation series of snow cover and seasonal freeze-thaw layer from 1965 to 2004 on the Tibetan Plateau has been established by using the observation data from meteorological stations. The sliding T-test, M-K test and B-G algorithm are used to verify abrupt changes of snow cover and seasonal freeze-thaw layer in the Tibetan plateau. The results show that the snow cover has not undergone an abrupt change, but the seasonal freeze-thaw layer obviously witnessed a rapid degradation in 1987, with the frozen soil depth being reduced by about 15 cm. It is also found that when there ~s less snow in the plateau region, precipitation in South China and Southwest China increases. But when the frozen soil is deep, precipitation in most of China apparently decreases. Both snow cover and seasonal freeze-thaw layer on the plateau can be used to predict the summer precipitation in China. However, if the impacts of snow cover and seasonal freeze-thaw layer are used at the same time, the predictability of summer precipitation can be significantly improved. The significant correlation zone of snow is located in middle reaches of the Yangtze River covering the Hexi Corridor and northeastern Inner Mongolia, and the seasonal freeze-thaw layer exists in Mt. Nanling, northern Shannxi and northwestern part of North China. The significant correlation zone of simultaneous impacts of snow cover and seasonal freeze-thaw layer is larger than that of either snow cover or seasonal freeze-thaw layer. There are three significant correlation zones extending from north to south： the north zone spreads from Mr. Daxinganling to the Hexi Corridor, crossing northern Mt. Taihang and northern Shannxi; the central zone covers middle and lower reaches of the Yangtze River; and the south zone extends from Mt. Wuyi to Yunnan and Guizhou Plateau through Mt. Nanling.
基金funded by the National Natural Science Foundation of China(Grant Nos.41330527 and 41505068)National Key Program for Global Change Research of China(Grant No.2010CB950500)Fundamental Research Funds of CAMS(Grant No.2015Y004)
文摘One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of ＂common but differentiated responsibilities＂. This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model（CESM）, we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases（GHGs）in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century.
文摘This is a letter from two Chinese scientists to Dr. Dahe Qin, Co-Chair of IPCC Working Group 1. Human society has taken an historical step to address climate change issue. However, how to understand climate change and how to response to climate change will always and everywhere lead various types of disagreements and disputes, thus affecting the pace of societies＇ promptly taking orderly human activity against climate change. In the letter, the two scientists bring up their thoughts and recommendations on how to carry out coordinated research on orderly human activity to cope with global climate change.
基金supported by the National Key Basic Research Program (No. 2007CB411505)the National Natural Science Foundation (No. 40705031)
文摘This paper presents an analysis of the mechanisms and impacts of snow cover and frozen soil in the Tibetan Plateau on the sum- mer precipitation in China, using RegCM3 version 3.1 model simulations. Comparisons of simulations vs. observations show that RegCM3 well captures these impacts. Results indicate that in a more-snow year with deep frozen soil there will be more precipita- tion in the Yangtze River Basin and central Northwest China, western Inner Mongolia, and Xinjiang, but less precipitation in Northeast China, North China, South China, and most of Southwest China. In a less-snow year with deep frozen soil, however, there will be more precipitation in Northeast China, North China, and southern South China, but less precipitation in the Yangtze River Basin and in northern South China. Such differences may be attributed to different combination patterns of melting snow and thawing frozen soil on the Plateau, which may change soil moisture as well as cause differences in energy absorption in the phase change processes of snow cover and frozen soil. These factors may produce more surface sensible heat in more-snow years when the fi＇ozen soil is deep than when the frozen soil is shallow. The higher surface sensible heat may lead to a stronger updraft over the Plateau, eventually contributing to a stronger South Asia High and West Pacific Subtropical High. Due to different values of the wind fields at 850 hPa, a convergence zone will form over the Yangtze River Basin, which may produce more summer pre- cipitation in the basin area but less precipitation in North China and South China. However, because soil moisture depends on ice content, in less-snow years with deep frozen soil, the soil moisture will be higher. The combination of higher frozen soil moisture with latent heat absorption in the phase change process may generate less surface sensible heat and consequently a weaker updraft motion over the Plateau. As a result, both the South Asia High and the West Pacific Subtropical High will be weaker, hence caus- ing more summer precipitation in northern China but less in southem China.
基金support of NSF Biophotonics Program and the NIH/National Center for Advancing Translational Science UCLA CTSI Grant UL1TR001881.
文摘The immunohistochemical(IHC)staining of the human epidermal growth factor receptor 2(HER2)biomarker is widely practiced in breast tissue analysis,preclinical studies,and diagnostic decisions,guiding cancer treatment and investigation of pathogenesis.HER2 staining demands laborious tissue treatment and chemical processing performed by a histotechnologist,which typically takes one day to prepare in a laboratory,increasing analysis time and associated costs.Here,we describe a deep learning-based virtual HER2 IHC staining method using a conditional generative adversarial network that is trained to rapidly transform autofluorescence microscopic images of unlabeled/label-free breast tissue sections into bright-field equivalent microscopic images,matching the standard HER2 IHC staining that is chemically performed on the same tissue sections.The efficacy of this virtual HER2 staining framework was demonstrated by quantitative analysis,in which three board-certified breast pathologists blindly graded the HER2 scores of virtually stained and immunohistochemically stained HER2 whole slide images(WSIs)to reveal that the HER2 scores determined by inspecting virtual IHC images are as accurate as their immunohistochemically stained counterparts.A second quantitative blinded study performed by the same diagnosticians further revealed that the virtually stained HER2 images exhibit a comparable staining quality in the level of nuclear detail,membrane clearness,and absence of staining artifacts with respect to their immunohistochemically stained counterparts.This virtual HER2 staining framework bypasses the costly,laborious,and time-consuming IHC staining procedures in laboratory and can be extended to other types of biomarkers to accelerate the IHC tissue staining used in life sciences and biomedical workflow.
文摘Surface with well-defined components and structures possesses unique electronic,magnetic,optical and chemical properties.As a result,surface chemistry research plays a crucial role in various fields such as catalysis,energy,materials,quantum,and microelectronics.Surface science mainly investigates the correspondence between surface property and functionality.Scanning probe microscopy(SPM)techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging,spectroscopy and manipulation at the single-atom level.In this review,we summarize recent advances in surface electronic,magnetic and optical properties characterized mainly by SPM-based methods.We focus on elucidating theπ-magnetism in graphene-based nanostructures,construction of spin qubits on surfaces,topology properties of surface organic structures,STM-based light emission,tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.
基金supported by the National Key Research and Development Program of China(2022YFD1201600,2021YFA1300100,and 2018YFE0203300)the National Natural Science Foundation of China(31972622 and 32241029)+6 种基金the State Key Program of National Natural Science Foundation of China(32030103)the Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-LZX0302,CSTB2022NSCQ-MSX0761,and cstc2020jcyj-cxtt X0001)the Fundamental Research Funds for the Central Universities(XDJK2020TJ001)the Key Project of Science and Technology Research Program of Chongqing Municipal Education Commission,China(KJZD-K202200205)the Chinese Academy of Sciences(CAS)Strategic Priority Research Program(XDB37010100)the Shennong Youth Talent Program(Ministry of Agriculture and Rural Affairs,China)the Chongqing Innovation Supporting Program for Oversea Returned Talents(CX2023069)。
文摘Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo.Here,we found that amphipol and digitonin stabilized the structure of natural silk fibroin(NSF)by a large-scale screening in vitro,and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen.Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm,rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules.Metal ions were required for NSF nanofibril formation.The successive p H decrease from posterior silk gland(PSG)to anterior silk gland(ASG)resulted in a gradual increase in NSF hydrophobicity,thus inducing the sol-gelation transition of NSF nanofibrils.NSF nanofibrils were randomly dispersed from PSG to ASG-1,and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning.Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and p H gradient,which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers.
基金supported by the National Natural Science Foundation of China(Nos.22225202,92356309,22132007,21991132,22172002)。
文摘Surface chemistry focuses on the investigation of the adsorption,migration,assembly,activation,reaction,and desorption of atoms and molecules at surfaces.Surface chemistry plays the pivotal roles in both fundamental science and applied technology.This review will summarize the recent progresses on surface assembly,synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy.Surface assemblies of water and small biomolecules,construction of Sierpin′ski triangles and surface chirality are summarized.On-surface synthesis of conjugated carbo-and heterocycles and other kinds of carbon nanostructures are surveyed.Surface model catalysis,including single-atom catalysis and electrochemical catalysis,are discussed at the single-atom level.
基金supported by the National Natural Science Foundation of China (41605036 and 41305053)the National Key Research and Development Program of China (2016YFA0602703)+1 种基金the National-Level Major Cultivation Project of Guangdong Province (2014GKXM058)the Open Project of the State Key Laboratory of Cryospheric Science (SKLCS-OP-2016-09)
文摘Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction between the coupled earth system models and the IAMs. This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University （BNU-ESM）. With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.
基金supported by the National Natural Science Foundation of China(nos.42306217,62202477,72225011,and 42276205)Hunan Provincial Natural Science Foundation of China(2023JJ10053)the National Key Research and Development Program of China(2021YFC3101500).
文摘INTRODUCTION.Natural disasters,including floods,storms,and tsunamis,pose a great threat to human societies.A recent study highlighted this concern,revealing that billions of people globally were exposed to flood hazards.1 In 2023,Super Typhoon Doksuri caused devasting floods in Beijing and Hebei areas,resulting in massive casualties and huge economic losses.Therefore,there is a need for a precise understanding of disaster processes,reliable forecasting of disaster effects,and timely warning of risks to prevent and mitigate major disasters.2 Numerical modeling stands as the predominant approach to meet these demands.However,the predictive accuracy of such numerical models could be degraded because of various factors:oversimplification of real processes,computational errors,fluctuations of complex environments(e.g.,terrains,precipitations,buildings,and plants),and the influence of human activities(e.g.,evacuation and rescue)during disasters.
基金supported by the National Natural Science Foundation of China (41975105)the National Key Research & Development Program of China (2018YFC1507705 and 2017YFC1502301)。
文摘Global mean surface temperature(GMST)is one of the most important large-scale indicators for characterizing climate change on Earth,and Surface Temperature(ST)is also the most accurate key climate element currently understood by scientists and the public.Even so,there have been extensive discussions about the accuracy of global(regional)surface temperature(air temperature)changes[lj.From the perspective of climatic data acquisition and data reliability,the current GMST series and the evaluation of global warming rates are all based on several observation-based datasets produced by combining anomalies of Land Surface Air Temperatures(LSAT)and Sea Surface Temperatures(SST).
基金supported by the Fundamental Research Funds for the Central Universities(2012YBXS27)the National Key Program for Global Change Research of China(2010CB950500)
文摘The carbon cycle is one of the fundamental climate change issues.Its long-term evolution largely affects the amplitude and trend of human-induced climate change,as well as the formulation and implementation of emission reduction policy and technology for stabilizing the atmospheric CO2concentration.Two earth system models incorporating the global carbon cycle,the Community Earth System Model and the Beijing Normal University-Earth System Model,were used to investigate the effect of the carbon cycle on the attribution of the historical responsibility for climate change.The simulations show that when compared with the criterion based on cumulative emissions,the developed(developing)countries’responsibility is reduced(increased)by 6%–10%using atmospheric CO2concentration as the criterion.This discrepancy is attributed to the fact that the developed world contributed approximately61%–68%(61%–64%)to the change in global oceanic(terrestrial)carbon sequestration for the period from 1850 to2005,whereas the developing world contributed approximately 32%–49%(36%–39%).Under a developed world emissions scenario,the relatively larger uptake of global carbon sinks reduced the developed countries’responsibility for carbon emissions but increased their responsibility for global ocean acidification(68%).In addition,the large emissions from the developed world reduced the efficiency of the global carbon sinks,which may affect the long-term carbon sequestration and exacerbate global warming in the future.Therefore,it is necessary to further consider the interaction between carbon emissions and the carbon cycle when formulating emission reduction policy.
基金supported by the National Key Research&Development Plan of China(No.2016YFA0602703 and No.2016YFC1401603)the special fund forthe Second Institute of Oceanography(No.JG1620)+3 种基金the National Natural Science Foundation of China(No.41705048,No.41605036 and No.41621064)Zhejiang Provincial Natural Science Foundation of China(No.LR16D060001)Sino-German cooperation in ocean and polar researchthe national-level major cultivation project of Guangdong Province(No.2014GKXM058)
文摘The areas covered by 1.5 ℃ and 2.0 ℃ warming thresholds under RCP2.6, RCP4.5, and RCP8.5 were analyzed based on 22 CMIP5 models. More than 90% of the model runs are in agreement that by the end of the 21 st century, near-surface air temperature changes over ~5%(~2%), ~40%(~18%), and ~92%(~86%)of the globe will cross the 1.5 ℃(2.0 ℃) threshold under RCP2.6, RCP4.5, and RCP8.5, respectively. Under RCP8.5, nearly the whole of North America, Europe + Russia, Africa, and Asia–Russia will cross the 1.5 ℃(2.0 ℃) threshold in ~2050(~2060), while the coverage rates over South America and Oceania are ~80%(~75%) and ~50%(~30%), respectively. The threshold-onset time(TOT) for 2 ℃ warming is earliest over Europe + Russia and North America, followed by Africa, Asia–Russia, South America, and finally Oceania under the RCP4.5 and RCP8.5 scenarios. The TOT for 1.5 ℃ is ~10–30 years ahead of that for 2.0 ℃.
