Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostat...Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical core.The NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer time.Recent advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic relationship.In this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the NAS.The NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)model.The forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,respectively.Finally,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic tendency.Corrected by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.展开更多
Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the resul...Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental ones.The deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different velocities.The results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact speed.In addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification phase.Gradient design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside outwards.Compared to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over half.With the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional honeycombs.The results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.展开更多
This paper describes the datasets from the Scenario Model Intercomparison Project(ScenarioMIP)simulation experiments run with the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System Model,GridPo...This paper describes the datasets from the Scenario Model Intercomparison Project(ScenarioMIP)simulation experiments run with the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System Model,GridPoint version 3(CAS FGOALS-g3).FGOALS-g3 is driven by eight shared socioeconomic pathways(SSPs)with different sets of future emission,concentration,and land-use scenarios.All Tier 1 and 2 experiments were carried out and were initialized using historical runs.A branch run method was used for the ensemble simulations.Model outputs were three-hourly,six-hourly,daily,and/or monthly mean values for the primary variables of the four component models.An evaluation and analysis of the simulations is also presented.The present results are expected to aid research into future climate change and socio-economic development.展开更多
Significant improvements have been achieved in microtia reconstruction using an autogenous costal cartilage framework.However,complications such as skin necrosis and cartilage exposure often destroy the final contour ...Significant improvements have been achieved in microtia reconstruction using an autogenous costal cartilage framework.However,complications such as skin necrosis and cartilage exposure often destroy the final contour of the reconstructed auricle.Local fascia flaps are commonly used in salvage surgery because of their reliability and satisfactory results.Here,we report the case of a 26-year-old woman with multiple skin necroses and cartilage exposure on day 21 after the first-stage microtia reconstruction.The exposure area was covered by a temporoparietal fascia flap as a single-stage procedure.The most essential subunits survived,and the esthetic concours were harmonious and natural at 12 months postoperatively.Temporoparietal fascia flaps are recommended as the surgical treatment for multiple skin necroses and cartilage exposure in microtia reconstruction.The axial-pattern temporoparietal fascia flap is reliable for salvage auricular reconstruction and ensures satisfactory results at long-term follow-up.展开更多
Gefitinib,erlotinib,afatinib and osimertinib have been recommended as the first-line treatment for epidermal growth factor receptor(EGFR)-mutated advanced non-small cell lung cancer(NSCLC),whereas no studies have comp...Gefitinib,erlotinib,afatinib and osimertinib have been recommended as the first-line treatment for epidermal growth factor receptor(EGFR)-mutated advanced non-small cell lung cancer(NSCLC),whereas no studies have compared the cost-effectiveness of these four tyrosine kinase inhibitors(TKIs)simultaneously in China.In the present study,we aimed to estimate the cost-effectiveness of erlotinib,gefitinib,afatinib and osimertinib for untreated EGFR-mutated advanced NSCLC.A Markov model was constructed to compare the 10-year impact of four TKIs for patients with treatment-naive EGFR-mutated advanced NSCLC from the perspective of the Chinese medical system.Clinical data and utility values were derived from published literature,and costs were obtained from Chinese official websites.The primary output indicator was the incremental cost-effectiveness ratio(ICER).Sensitivity analyses were performed to test the robustness of the model.We found that afatinib was estimated to spend the lowest cost with minimum life-years(LYs),while osimertinib was the most expensive regimen with maximum LYs.The ICER of gefitinib versus afatinib was$732/quality-adjusted life-year(QALY),which was less than the willingness-to-pay(WTP)of$29382/QALY.Compared with gefitinib,erlotinib yielded a higher cost and a shorter lifetime,hence it was identified as a dominated strategy.Then,osimertinib was compared to gefitinib,which produced an ICER of$71330/QALY,exceeding the WTP.It suggested that gefitinib was the most cost-effective regimen as the first-line treatment for EGFR-mutated advanced NSCLC.Decreasing the osimertinib price or increasing the WTP threshold to$68558/QALY might enhance the favorability of the outcome,by which osimertinib might become more cost-effective.One-way sensitivity analysis manifested that the model was robust.展开更多
Lung cancer is the most widespread type of cancer and the primary cause of cancer-related death in the world.In this study,we aimed to analyze the cost-effectiveness of second-line chemotherapy strategies based on gem...Lung cancer is the most widespread type of cancer and the primary cause of cancer-related death in the world.In this study,we aimed to analyze the cost-effectiveness of second-line chemotherapy strategies based on gemcitabine,pemetrexed,and docetaxel for advanced non-squamous non-small cell lung cancer patients in China.A Markov model based on three states,progression-free survival,progressed survival and death,was constructed to simulate the progression of the disease in a 6-year horizon.Sensitivity analysis was performed to evaluate the robustness of the model.The primary outcome of the model was the incremental cost-effectiveness ratio at a willingness-to-pay threshold of 3×per capita GDP of China in 2018($29383).The baseline model results showed that the quality-adjusted life years over the course of the disease associated with second-line chemotherapy strategies were 0.233,0.417 and 0.272 for gemcitabine,pemetrexed and docetaxel,respectively,and the corresponding total costs were$5321.02,$12143.94,and$9479.42.Gemcitabine,pemetrexed and docetaxel resulted in the incremental cost-effectiveness ratios of$37081.09 and$106625.64 per quality-adjusted life year gained.The incremental cost-effectiveness ratio of pemetrexed and docetaxel compared with gemcitabine exceeded the willingness-to-pay threshold.One-way sensitivity analysis showed that the utility value of gemcitabine in the progressed survival state was the most influential parameter.展开更多
火星探测是当前国家高科技竞争力的标志,世界航天强国均研制火星大气模式,为登陆探测提供气象环境保障.本文描述了我国新一代火星大气模式(global open planetary atmospheric model for Mars,缩写GoPlanet-Mars,简称GoMars)的研制,其...火星探测是当前国家高科技竞争力的标志,世界航天强国均研制火星大气模式,为登陆探测提供气象环境保障.本文描述了我国新一代火星大气模式(global open planetary atmospheric model for Mars,缩写GoPlanet-Mars,简称GoMars)的研制,其中的动力框架完全自主研发,具有二阶精度、能保证质量守恒.GoMars引进并耦合了美国宇航局艾姆斯研究中心的火星物理过程,具备模拟沙尘、水和CO_(2)的能力.基于我国“祝融号”、美国“维京1号、2号”的实测数据以及国际火星大气全球数据集评估了GoMars,结果表明:GoMars能成功再现3个探测器记录的火星大气独特的地表气压“两峰两谷”特征;在全球地表温度、纬向急流、极区CO_(2)冰和沙尘方面,GoMars也具备良好的模拟性能,可为我国火星探测计划实施提供新的气象环境保障手段.展开更多
This study shows a new way to implement terrain-following s-coordinate in a numerical model,which does not lead to the well-known"pressure gradient force(PGF)"problem.First,the causes of the PGF problemare a...This study shows a new way to implement terrain-following s-coordinate in a numerical model,which does not lead to the well-known"pressure gradient force(PGF)"problem.First,the causes of the PGF problemare analyzedwith existing methods that are categorized into two different types based on the causes.Then,the new method that bypasses the PGF problem all together is proposed.By comparing these threemethods and analyzing the expression of the scalar gradient in a curvilinear coordinate system,this study finds out that only when using the covariant scalar equations of s-coordinate will the PGF computational form have one term in each momentum component equation,thereby avoiding the PGF problem completely.A convenient way of implementing the covariant scalar equations of s-coordinate in a numerical atmospheric model is illustrated,which is to set corresponding parameters in the scalar equations of the Cartesian coordinate.Finally,two idealized experimentsmanifest that the PGF calculated with the new method is more accurate than using the classic one.This method can be used for oceanic models as well,and needs to be tested in both the atmospheric and oceanic models.展开更多
The basic terrain-following(BTF)coordinate simplifies the lower boundary conditions of a numerical model but leads to numerical error and instability on steep terrain.Hybrid terrain-following(HTF)coordinates with smoo...The basic terrain-following(BTF)coordinate simplifies the lower boundary conditions of a numerical model but leads to numerical error and instability on steep terrain.Hybrid terrain-following(HTF)coordinates with smooth slopes of vertical layers(slopeVL)generally overcome this difficulty.Therefore,the HTF coordinate becomes very desirable for atmospheric and oceanic numerical models.However,improper vertical layering in HTF coordinates may also increase the incidence of error.Except for the slopeVL of an HTF coordinate,this study further optimizes the HTF coordinate focusing on the thickness of vertical layers(thickVL).Four HTF coordinates(HTF1–HTF4)with similar slopeVL but different vertical transition methods of thickVL are designed,and the relationship between thickVL and numerical errors in each coordinate is compared in the classic idealized thermal convection[two-dimensional(2D)rising bubble]experiment over steep terrain.The errors of potential temperatureθand vertical velocity w are reduced most,by approximately 70%and 40%,respectively,in the HTF1 coordinate,with a monotonic increase in thickVL according to the increasing height;however,the errors ofθincreased in all the other HTF coordinates,with nonmonotonic thickVLs.Furthermore,analyses of the errors of vertical pressure gradient force(VPGF)show that due to the interpolation errors of thickVL,the inflection points in the vertical transition of thickVL induce the initial VPGF errors;therefore,the HTF1 coordinate with a monotonic increase in thickVL has the smallest errors among all the coordinates.More importantly,the temporal evolution of VPGF errors manifests top-type VPGF errors that propagate upward gradually during the time integration.Only the HTF1 and HTF4 coordinates with a monotonic increase in thickVL near the top of the terrain can suppress this propagation.This optimized HTF coordinate(i.e.,HTF1)can be a reference for designing a vertical thickVL in a numerical model.展开更多
基金supported by the National Science Foundation of China(Grant No.42230606)。
文摘Here,a nonhydrostatic alternative scheme(NAS)is proposed for the grey zone where the nonhydrostatic impact on the atmosphere is evident but not large enough to justify the necessity to include an implicit nonhydrostatic solver in an atmospheric dynamical core.The NAS is designed to replace this solver,which can be incorporated into any hydrostatic models so that existing well-developed hydrostatic models can effectively serve for a longer time.Recent advances in machine learning(ML)provide a potential tool for capturing the main complicated nonlinear-nonhydrostatic relationship.In this study,an ML approach called a neural network(NN)was adopted to select leading input features and develop the NAS.The NNs were trained and evaluated with 12-day simulation results of dry baroclinic-wave tests by the Weather Research and Forecasting(WRF)model.The forward time difference of the nonhydrostatic tendency was used as the target variable,and the five selected features were the nonhydrostatic tendency at the last time step,and four hydrostatic variables at the current step including geopotential height,pressure in two different forms,and potential temperature,respectively.Finally,a practical NAS was developed with these features and trained layer by layer at a 20-km horizontal resolution,which can accurately reproduce the temporal variation and vertical distribution of the nonhydrostatic tendency.Corrected by the NN-based NAS,the improved hydrostatic solver at different horizontal resolutions can run stably for at least one month and effectively reduce most of the nonhydrostatic errors in terms of system bias,anomaly root-mean-square error,and the error of the wave spatial pattern,which proves the feasibility and superiority of this scheme.
基金This work is supported by the National Natural Science Foundation of China(No.11902232).
文摘Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental ones.The deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different velocities.The results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact speed.In addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification phase.Gradient design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside outwards.Compared to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over half.With the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional honeycombs.The results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.
基金This study was supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0603903,2017YFA0603901,and 2017YFA0603902)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB42010404)the National Basic Research(973)Program of China(Grant Nos.2015CB954102).
文摘This paper describes the datasets from the Scenario Model Intercomparison Project(ScenarioMIP)simulation experiments run with the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System Model,GridPoint version 3(CAS FGOALS-g3).FGOALS-g3 is driven by eight shared socioeconomic pathways(SSPs)with different sets of future emission,concentration,and land-use scenarios.All Tier 1 and 2 experiments were carried out and were initialized using historical runs.A branch run method was used for the ensemble simulations.Model outputs were three-hourly,six-hourly,daily,and/or monthly mean values for the primary variables of the four component models.An evaluation and analysis of the simulations is also presented.The present results are expected to aid research into future climate change and socio-economic development.
基金This work was supported by the National Natural Science Foundation of China(no.81974291)the Clinical Research Program of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine(JYLJ201914).
文摘Significant improvements have been achieved in microtia reconstruction using an autogenous costal cartilage framework.However,complications such as skin necrosis and cartilage exposure often destroy the final contour of the reconstructed auricle.Local fascia flaps are commonly used in salvage surgery because of their reliability and satisfactory results.Here,we report the case of a 26-year-old woman with multiple skin necroses and cartilage exposure on day 21 after the first-stage microtia reconstruction.The exposure area was covered by a temporoparietal fascia flap as a single-stage procedure.The most essential subunits survived,and the esthetic concours were harmonious and natural at 12 months postoperatively.Temporoparietal fascia flaps are recommended as the surgical treatment for multiple skin necroses and cartilage exposure in microtia reconstruction.The axial-pattern temporoparietal fascia flap is reliable for salvage auricular reconstruction and ensures satisfactory results at long-term follow-up.
文摘Gefitinib,erlotinib,afatinib and osimertinib have been recommended as the first-line treatment for epidermal growth factor receptor(EGFR)-mutated advanced non-small cell lung cancer(NSCLC),whereas no studies have compared the cost-effectiveness of these four tyrosine kinase inhibitors(TKIs)simultaneously in China.In the present study,we aimed to estimate the cost-effectiveness of erlotinib,gefitinib,afatinib and osimertinib for untreated EGFR-mutated advanced NSCLC.A Markov model was constructed to compare the 10-year impact of four TKIs for patients with treatment-naive EGFR-mutated advanced NSCLC from the perspective of the Chinese medical system.Clinical data and utility values were derived from published literature,and costs were obtained from Chinese official websites.The primary output indicator was the incremental cost-effectiveness ratio(ICER).Sensitivity analyses were performed to test the robustness of the model.We found that afatinib was estimated to spend the lowest cost with minimum life-years(LYs),while osimertinib was the most expensive regimen with maximum LYs.The ICER of gefitinib versus afatinib was$732/quality-adjusted life-year(QALY),which was less than the willingness-to-pay(WTP)of$29382/QALY.Compared with gefitinib,erlotinib yielded a higher cost and a shorter lifetime,hence it was identified as a dominated strategy.Then,osimertinib was compared to gefitinib,which produced an ICER of$71330/QALY,exceeding the WTP.It suggested that gefitinib was the most cost-effective regimen as the first-line treatment for EGFR-mutated advanced NSCLC.Decreasing the osimertinib price or increasing the WTP threshold to$68558/QALY might enhance the favorability of the outcome,by which osimertinib might become more cost-effective.One-way sensitivity analysis manifested that the model was robust.
基金Startup Fund for Scientific Research,Fujian Medical University(Grant No.2018QH1091)。
文摘Lung cancer is the most widespread type of cancer and the primary cause of cancer-related death in the world.In this study,we aimed to analyze the cost-effectiveness of second-line chemotherapy strategies based on gemcitabine,pemetrexed,and docetaxel for advanced non-squamous non-small cell lung cancer patients in China.A Markov model based on three states,progression-free survival,progressed survival and death,was constructed to simulate the progression of the disease in a 6-year horizon.Sensitivity analysis was performed to evaluate the robustness of the model.The primary outcome of the model was the incremental cost-effectiveness ratio at a willingness-to-pay threshold of 3×per capita GDP of China in 2018($29383).The baseline model results showed that the quality-adjusted life years over the course of the disease associated with second-line chemotherapy strategies were 0.233,0.417 and 0.272 for gemcitabine,pemetrexed and docetaxel,respectively,and the corresponding total costs were$5321.02,$12143.94,and$9479.42.Gemcitabine,pemetrexed and docetaxel resulted in the incremental cost-effectiveness ratios of$37081.09 and$106625.64 per quality-adjusted life year gained.The incremental cost-effectiveness ratio of pemetrexed and docetaxel compared with gemcitabine exceeded the willingness-to-pay threshold.One-way sensitivity analysis showed that the utility value of gemcitabine in the progressed survival state was the most influential parameter.
文摘火星探测是当前国家高科技竞争力的标志,世界航天强国均研制火星大气模式,为登陆探测提供气象环境保障.本文描述了我国新一代火星大气模式(global open planetary atmospheric model for Mars,缩写GoPlanet-Mars,简称GoMars)的研制,其中的动力框架完全自主研发,具有二阶精度、能保证质量守恒.GoMars引进并耦合了美国宇航局艾姆斯研究中心的火星物理过程,具备模拟沙尘、水和CO_(2)的能力.基于我国“祝融号”、美国“维京1号、2号”的实测数据以及国际火星大气全球数据集评估了GoMars,结果表明:GoMars能成功再现3个探测器记录的火星大气独特的地表气压“两峰两谷”特征;在全球地表温度、纬向急流、极区CO_(2)冰和沙尘方面,GoMars也具备良好的模拟性能,可为我国火星探测计划实施提供新的气象环境保障手段.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-Q11-04)the National Basic Research Program of China(973 Program,Grant No.2011CB309704)The second author was supported by the National Natural Science Foundation of China(NSFC)under Grant No.40875022,41175064 and 40633016.
文摘This study shows a new way to implement terrain-following s-coordinate in a numerical model,which does not lead to the well-known"pressure gradient force(PGF)"problem.First,the causes of the PGF problemare analyzedwith existing methods that are categorized into two different types based on the causes.Then,the new method that bypasses the PGF problem all together is proposed.By comparing these threemethods and analyzing the expression of the scalar gradient in a curvilinear coordinate system,this study finds out that only when using the covariant scalar equations of s-coordinate will the PGF computational form have one term in each momentum component equation,thereby avoiding the PGF problem completely.A convenient way of implementing the covariant scalar equations of s-coordinate in a numerical atmospheric model is illustrated,which is to set corresponding parameters in the scalar equations of the Cartesian coordinate.Finally,two idealized experimentsmanifest that the PGF calculated with the new method is more accurate than using the classic one.This method can be used for oceanic models as well,and needs to be tested in both the atmospheric and oceanic models.
基金Supported by the National Natural Science Foundation of China(42230606)14th Five-Year Plan Basic Research Program of Institute of Atmospheric Physics,Chinese Academy of Sciences(E268081801)National Key Research and Development Program of China(2017YFA0603901)。
文摘The basic terrain-following(BTF)coordinate simplifies the lower boundary conditions of a numerical model but leads to numerical error and instability on steep terrain.Hybrid terrain-following(HTF)coordinates with smooth slopes of vertical layers(slopeVL)generally overcome this difficulty.Therefore,the HTF coordinate becomes very desirable for atmospheric and oceanic numerical models.However,improper vertical layering in HTF coordinates may also increase the incidence of error.Except for the slopeVL of an HTF coordinate,this study further optimizes the HTF coordinate focusing on the thickness of vertical layers(thickVL).Four HTF coordinates(HTF1–HTF4)with similar slopeVL but different vertical transition methods of thickVL are designed,and the relationship between thickVL and numerical errors in each coordinate is compared in the classic idealized thermal convection[two-dimensional(2D)rising bubble]experiment over steep terrain.The errors of potential temperatureθand vertical velocity w are reduced most,by approximately 70%and 40%,respectively,in the HTF1 coordinate,with a monotonic increase in thickVL according to the increasing height;however,the errors ofθincreased in all the other HTF coordinates,with nonmonotonic thickVLs.Furthermore,analyses of the errors of vertical pressure gradient force(VPGF)show that due to the interpolation errors of thickVL,the inflection points in the vertical transition of thickVL induce the initial VPGF errors;therefore,the HTF1 coordinate with a monotonic increase in thickVL has the smallest errors among all the coordinates.More importantly,the temporal evolution of VPGF errors manifests top-type VPGF errors that propagate upward gradually during the time integration.Only the HTF1 and HTF4 coordinates with a monotonic increase in thickVL near the top of the terrain can suppress this propagation.This optimized HTF coordinate(i.e.,HTF1)can be a reference for designing a vertical thickVL in a numerical model.
