Earth abundant O3-type NaFe_(0.5)Mn_(0.5)O_(2)layered oxide is regarded as one of the most promising cathodes for sodium ion batteries due to its low cost and high energy density.However,its poor structural stability ...Earth abundant O3-type NaFe_(0.5)Mn_(0.5)O_(2)layered oxide is regarded as one of the most promising cathodes for sodium ion batteries due to its low cost and high energy density.However,its poor structural stability and cycle life strongly impede the practical application.Herein,the dynamic phase evolution as well as charge compensation mechanism of O3-type NaFe_(0.5)Mn_(0.5)O_(2)cathode during sodiation/desodiation are revealed by a systemic study with operando X-ray diffraction and X-ray absorption spectroscopy,high resolution neutron powder diffraction and neutron pair distribution functions.The layered structure experiences a phase transition of O3→P3→OP2→ramsdellite during the desodiation,and a new O3’phase is observed at the end of the discharge state(1.5 V).The density functional theory(DFT)calculations and nPDF results suggest that depletion of Na^(+)ions induces the movement of Fe into Na layer resulting the formation of an inert ramsdellite phase thus causing the loss of capacity and structural integrity.Meanwhile,the operando XAS clarified the voltage regions for active Mn^(3+)/Mn^(4+)and Fe^(3+)/Fe^(4+)redox couples.This work points out the universal underneath problem for Fe-based layered oxide cathodes when cycled at high voltage and highlights the importance to suppress Fe migration regarding the design of high energy O3-type cathodes for sodium ion batteries.展开更多
The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists ha...The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.展开更多
Currently, there is still no effective curative treatment for the development of late-stage liver fibrosis. Here, we have illustrated that TB001, a dual glucagon-like peptide-1 receptor/glucagon receptor(GLP-1 R/GCGR)...Currently, there is still no effective curative treatment for the development of late-stage liver fibrosis. Here, we have illustrated that TB001, a dual glucagon-like peptide-1 receptor/glucagon receptor(GLP-1 R/GCGR) agonist with higher affinity towards GCGR, could retard the progression of liver fibrosis in various rodent models, with remarkable potency, selectivity, extended half-life and low toxicity. Four types of liver fibrosis animal models which were induced by CCl_(4), a-naphthyl-isothiocyanate(ANIT), bile duct ligation(BDL) and Schistosoma japonicum were used in our study. We found that TB001 treatment dose-dependently significantly attenuated liver injury and collagen accumulation in these animal models. In addition to decreased levels of extracellular matrix(ECM) accumulation during hepatic injury, activation of hepatic stellate cells was also inhibited via suppression of TGF-β expression as well as downstream Smad signaling pathways particularly in CCl_(4)-and S. japonicum-induced liver fibrosis. Moreover, TB001 attenuated liver fibrosis through blocking downstream activation of proinflammatory nuclear factor kappa B/NF-kappa-B inhibitor alpha(NFκB/IKBa) pathways as well as cJun N-terminal kinase(JNK)-dependent induction of hepatocyte apoptosis. Furthermore, GLP-1 R and/or GCGR knock-down results represented GCGR played an important role in ameliorating CCl_(4)-induced hepatic fibrosis. Therefore, TB001 can be used as a promising therapeutic candidate for the treatment of multiple causes of hepatic fibrosis demonstrated by our extensive pre-clinical evaluation of TB001.展开更多
Microblogging services nformation and express opinions pro by vide a novel and popular communication scheme for Web users to share publishing short posts, which usually reflect the users＇ daily life. We can thus mode...Microblogging services nformation and express opinions pro by vide a novel and popular communication scheme for Web users to share publishing short posts, which usually reflect the users＇ daily life. We can thus model the users＇ daily status and interests according to their posts. Because of the high complexity and the large amount of the content of the microblog users＇ posts, it is necessary to provide a quick summary of the users＇ life status, both for personal users and commercial services. It is non-trivial to summarize the life status of microblog users, particularly when the summary is conducted over a long period. In this paper, we present a compact interactive visualization prototype, LifeCircle, as an efficient summary for exploring the long-term life status of microblog users. The radial visualization provides multiple views for a given microblog user, including annual topics, monthly keywords, monthly sentiments, and temporal trends of posts. We tightly integrate interactive visualization with novel and state-of-the-art microblogging analytics to maximize their advantages. We implement LifeCircle on Sina Weibo, the most popular microblogging service in China, and illustrate the effectiveness of our prototype with various case studies. Results show that our prototype makes users nostalgic and makes them reminiscent about past events, which helps them to better understand themselves and others展开更多
The development of next-generation layered oxide cathodes for high-energy-density electrical vehicle Li-ion batteries(LIBs)is an urgent topic.The existing method is achieved by continuously increasing the Ni contents ...The development of next-generation layered oxide cathodes for high-energy-density electrical vehicle Li-ion batteries(LIBs)is an urgent topic.The existing method is achieved by continuously increasing the Ni contents of Ni-based layered oxides,but it has been limited to LiNiO_(2).To break this limit and attain increased energy densities,a promising strategy,which involves the introduction of excess Li ions into transition metal(TM)layers to form Li-excess compounds Li_(2)MO_(3)(M is a TM cation),has attracted enormous interest recently.However,another strategy,which has been neglected in recent years,involves the insertion of an extra layer of Li ions between the TM and original Li layers to form Li_(2)MO_(2).In this study,typical reversible Li_(2)NiO_(3) and 1T-Li_(2)NiO_(2) were selected as two representative cathodes to break the limit of LiNiO_(2),thereby availing comprehensive comparison with LiNiO_(2) regarding their overall properties as cathodes from a theoretical perspective.Interestingly,dissimilar to the Ni^(3+)/Ni^(4+)monoelectron cationic redox associated with LiNiO_(2),a polaronic anionic redox reaction occurs in Li_(2)NiO_(3),while a reversible Ni^(2+)/Ni^(4+)double-electron redox reaction accompanied by insulator-metal transition occurs in Li_(2)NiO_(2).Owing to this double-electron cationic activity,Li_(2)NiO_(2) exhibits absolute advantages over the other two materials(LiNiO_(2) and Li_(2)NiO_(3))as cathodes for LIBs in terms of the capacity,energy density,electronic conductivity,and thermal stability,thus rendering it the most promising candidate for next-generation layered oxide cathodes with high energy densities to break the limit of LiNiO_(2).展开更多
基金financial support of the Guangdong Basic and Applied Basic Research Foundation(2019A1515110897 and 2019B1515120028)。
文摘Earth abundant O3-type NaFe_(0.5)Mn_(0.5)O_(2)layered oxide is regarded as one of the most promising cathodes for sodium ion batteries due to its low cost and high energy density.However,its poor structural stability and cycle life strongly impede the practical application.Herein,the dynamic phase evolution as well as charge compensation mechanism of O3-type NaFe_(0.5)Mn_(0.5)O_(2)cathode during sodiation/desodiation are revealed by a systemic study with operando X-ray diffraction and X-ray absorption spectroscopy,high resolution neutron powder diffraction and neutron pair distribution functions.The layered structure experiences a phase transition of O3→P3→OP2→ramsdellite during the desodiation,and a new O3’phase is observed at the end of the discharge state(1.5 V).The density functional theory(DFT)calculations and nPDF results suggest that depletion of Na^(+)ions induces the movement of Fe into Na layer resulting the formation of an inert ramsdellite phase thus causing the loss of capacity and structural integrity.Meanwhile,the operando XAS clarified the voltage regions for active Mn^(3+)/Mn^(4+)and Fe^(3+)/Fe^(4+)redox couples.This work points out the universal underneath problem for Fe-based layered oxide cathodes when cycled at high voltage and highlights the importance to suppress Fe migration regarding the design of high energy O3-type cathodes for sodium ion batteries.
文摘The windage loss caused by protrusion in a rotor–stator cavity has been studied in detail,and there are abundant fitting formulas that have been summarized to calculate the moment coefficients.Some other theorists have emphasized its effect on the sealing efficiency,proposing that installation of protrusion could alleviate gas ingestion.However,the protrusion shape which is an influential factor on the sealing efficiency has not been focused in previous research.Using the experimental method of measuring CO2 volume fraction,cavity pressure,and power consumption,we investigated the effects of several typical protrusion shapes on various parameters for two sealing structures,in order to obtain the optimal shape.Results showed that a variation of the protrusion shape had little impact on the static pressure,but the total pressure and the sealing efficiency increased in different degrees.Furthermore,even though the hexagon shape resulted in the highest sealing efficiency,we observed that the drop shape had the best overall performance in all of the eight models,which could result in higher efficiency of the turbine cavity.The combination of a radial seal structure and protrusion could improve sealing efficiency better.
基金the financial support from the National Natural Science Foundation of China (No.91853106)the Program for Guangdong Introducing Innovative and Enterpre-neurial Teams (No.2016ZT06Y337,China)+3 种基金Guangdong Provincial Key Laboratory of Construction Foundation (No.2019B030301005,China)Shenzhen Science and Technology Program (JSGG20200225153121723,China)the Fundamental Research Funds for the Central Universities (No.19ykzd25,China)CAMS Innovation Fund for Medical Sciences (CIFMS,2019-I2M-5-074,China)。
文摘Currently, there is still no effective curative treatment for the development of late-stage liver fibrosis. Here, we have illustrated that TB001, a dual glucagon-like peptide-1 receptor/glucagon receptor(GLP-1 R/GCGR) agonist with higher affinity towards GCGR, could retard the progression of liver fibrosis in various rodent models, with remarkable potency, selectivity, extended half-life and low toxicity. Four types of liver fibrosis animal models which were induced by CCl_(4), a-naphthyl-isothiocyanate(ANIT), bile duct ligation(BDL) and Schistosoma japonicum were used in our study. We found that TB001 treatment dose-dependently significantly attenuated liver injury and collagen accumulation in these animal models. In addition to decreased levels of extracellular matrix(ECM) accumulation during hepatic injury, activation of hepatic stellate cells was also inhibited via suppression of TGF-β expression as well as downstream Smad signaling pathways particularly in CCl_(4)-and S. japonicum-induced liver fibrosis. Moreover, TB001 attenuated liver fibrosis through blocking downstream activation of proinflammatory nuclear factor kappa B/NF-kappa-B inhibitor alpha(NFκB/IKBa) pathways as well as cJun N-terminal kinase(JNK)-dependent induction of hepatocyte apoptosis. Furthermore, GLP-1 R and/or GCGR knock-down results represented GCGR played an important role in ameliorating CCl_(4)-induced hepatic fibrosis. Therefore, TB001 can be used as a promising therapeutic candidate for the treatment of multiple causes of hepatic fibrosis demonstrated by our extensive pre-clinical evaluation of TB001.
基金supported by the National Natural Science Foundation of China (Nos. 61170196 and 61202140)by the Singapore National Research Foundation under its International Research Centre @ Singapore Funding Initiative and administered by the IDM Programme Office
文摘Microblogging services nformation and express opinions pro by vide a novel and popular communication scheme for Web users to share publishing short posts, which usually reflect the users＇ daily life. We can thus model the users＇ daily status and interests according to their posts. Because of the high complexity and the large amount of the content of the microblog users＇ posts, it is necessary to provide a quick summary of the users＇ life status, both for personal users and commercial services. It is non-trivial to summarize the life status of microblog users, particularly when the summary is conducted over a long period. In this paper, we present a compact interactive visualization prototype, LifeCircle, as an efficient summary for exploring the long-term life status of microblog users. The radial visualization provides multiple views for a given microblog user, including annual topics, monthly keywords, monthly sentiments, and temporal trends of posts. We tightly integrate interactive visualization with novel and state-of-the-art microblogging analytics to maximize their advantages. We implement LifeCircle on Sina Weibo, the most popular microblogging service in China, and illustrate the effectiveness of our prototype with various case studies. Results show that our prototype makes users nostalgic and makes them reminiscent about past events, which helps them to better understand themselves and others
基金financially supported by the starting fund of Peking University,Shenzhen Graduate School and Fujian Science&Technology Innovation Laboratory for Energy Devices of China(21C-LAB)。
文摘The development of next-generation layered oxide cathodes for high-energy-density electrical vehicle Li-ion batteries(LIBs)is an urgent topic.The existing method is achieved by continuously increasing the Ni contents of Ni-based layered oxides,but it has been limited to LiNiO_(2).To break this limit and attain increased energy densities,a promising strategy,which involves the introduction of excess Li ions into transition metal(TM)layers to form Li-excess compounds Li_(2)MO_(3)(M is a TM cation),has attracted enormous interest recently.However,another strategy,which has been neglected in recent years,involves the insertion of an extra layer of Li ions between the TM and original Li layers to form Li_(2)MO_(2).In this study,typical reversible Li_(2)NiO_(3) and 1T-Li_(2)NiO_(2) were selected as two representative cathodes to break the limit of LiNiO_(2),thereby availing comprehensive comparison with LiNiO_(2) regarding their overall properties as cathodes from a theoretical perspective.Interestingly,dissimilar to the Ni^(3+)/Ni^(4+)monoelectron cationic redox associated with LiNiO_(2),a polaronic anionic redox reaction occurs in Li_(2)NiO_(3),while a reversible Ni^(2+)/Ni^(4+)double-electron redox reaction accompanied by insulator-metal transition occurs in Li_(2)NiO_(2).Owing to this double-electron cationic activity,Li_(2)NiO_(2) exhibits absolute advantages over the other two materials(LiNiO_(2) and Li_(2)NiO_(3))as cathodes for LIBs in terms of the capacity,energy density,electronic conductivity,and thermal stability,thus rendering it the most promising candidate for next-generation layered oxide cathodes with high energy densities to break the limit of LiNiO_(2).
