In order to provide technical supports for designing a new type of spiral plate forming machine, FEM analysis and simulation were carried out based on pressing tests. Deformation, stress distribution, residual stress ...In order to provide technical supports for designing a new type of spiral plate forming machine, FEM analysis and simulation were carried out based on pressing tests. Deformation, stress distribution, residual stress and spring back of the spiral plate were calculated. Relationships between the spiral pitch to inclination angle of the punch and die, material properties and thickness of the plate were analyzed. A data converter was developed and effectively used in the analysis. The results of FEM analysis and simulation have been applied to design the spiral plate forming machines.展开更多
The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigate...The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.展开更多
Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contain...Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contained galacturonic acid,galactose,xylose,arabinose,and rhamnose with the main chain structure of→4)-α-d-GalAp-(1→and→6)-β-d-Galp-(1→and the branched structure of→5)-α-l-Araf-(1→.Animal experiments showed that compared with Model group,SUSP-4 significantly improved body weight status,disease activity index(DAI),colonic shortening,and histopathological damage,and elevated occludin and zonula occludens protein 1(ZO-1)expression in mice induced by dextran sulfate sodium salt(DSS).16S ribosomal RNA(rRNA)sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes.Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism,which was further confirmed by a targeted metabolism study.Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice.A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B(p-NF-κB)and cyclooxygenase-2(COX-2)and elevating NF-E2-related factor 2(Nrf2)levels compared with Model group.In conclusion,SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD.This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD,showing great potential for in-depth research and development applications.展开更多
Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their ...Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia.展开更多
基金Supported by the New-Cooperation Project of Japan Ministry of Economy,Trade and Industry
文摘In order to provide technical supports for designing a new type of spiral plate forming machine, FEM analysis and simulation were carried out based on pressing tests. Deformation, stress distribution, residual stress and spring back of the spiral plate were calculated. Relationships between the spiral pitch to inclination angle of the punch and die, material properties and thickness of the plate were analyzed. A data converter was developed and effectively used in the analysis. The results of FEM analysis and simulation have been applied to design the spiral plate forming machines.
基金This research is funded by the National Natural Science Foundation of China(Grant No.42075050)Fundamental Research Funds for the Central Universities(Grant No.K20220232).
文摘The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.
基金the funding from the Spring City Plan of the High-Level Talent Promotion and Training Project of Kunming,China(Grant No.:2022SCP008)the Independent Research Fund of Yunnan Characteristic Plant Extraction Laboratory,China(Grant No.:2022YKZY001).
文摘Inflammatory bowel disease(IBD)is a serious disorder,and exploration of active compounds to treat it is necessary.An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata(Desv.)Spring,which contained galacturonic acid,galactose,xylose,arabinose,and rhamnose with the main chain structure of→4)-α-d-GalAp-(1→and→6)-β-d-Galp-(1→and the branched structure of→5)-α-l-Araf-(1→.Animal experiments showed that compared with Model group,SUSP-4 significantly improved body weight status,disease activity index(DAI),colonic shortening,and histopathological damage,and elevated occludin and zonula occludens protein 1(ZO-1)expression in mice induced by dextran sulfate sodium salt(DSS).16S ribosomal RNA(rRNA)sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes.Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism,which was further confirmed by a targeted metabolism study.Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice.A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B(p-NF-κB)and cyclooxygenase-2(COX-2)and elevating NF-E2-related factor 2(Nrf2)levels compared with Model group.In conclusion,SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD.This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD,showing great potential for in-depth research and development applications.
基金National Natural Science Foundation of China(42230603,42275020)Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)+3 种基金Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(2020B1212060025)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021001)Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,MNR(QNHX2310)Future Earth Early-Career Fellowship of the Future Earth Global Secretariat Hub China。
文摘Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia.
