The number of people travelling to high-altitude areas or participating in mountain sports is increasing.For individuals visiting such terrains for the first time,the lack of adaptation to the hypobaric hypoxic enviro...The number of people travelling to high-altitude areas or participating in mountain sports is increasing.For individuals visiting such terrains for the first time,the lack of adaptation to the hypobaric hypoxic environment can lead to the deterioration of gastrointestinal function and barriers.In more severe cases,this lack of acclimatisation may lead to acute high-altitude illness.At present,the prevention and treatment of these issues primarily revolve around strategies such as descending to lower altitudes,oxygen supplementation,and medication.However,the available intervention measures to prevent health problems resulting from high-altitude environments remain limited.In this review,we discuss common altitude-related illnesses,including gastrointestinal problems.Moreover,we explore the potential of commonly used medications and dietary supplements in alleviating altitude-related issues.This review can provide a basis for future research on modulating the gut microbiota for mitigating high-altitude illness.展开更多
To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black thr...To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black through a strategy involving modified glycol reduction and chemical etching.The obtained Pt36Co/C catalyst exhibits a much larger electrochemical surface area(ECSA)and an improved ORR electrocatalytic activity compared to commercial Pt/C.Moreover,an electrode prepared with Pt36Co/C was further evaluated under H2-air single cell test conditions,and exhibited a maximum specific power density of 10.27 W mgPt^-1,which is 1.61 times higher than that of a conventional Pt/C electrode and also competitive with most state-of-the-art Pt-based architectures.In addition,the changes in ECSA,power density,and reacting resistance during the accelerated degradation process further demonstrate the enhanced durability of the Pt36Co/C electrode.The superior performance observed in this work can be attributed to the synergy between the ultrasmall size and homogeneous distribution of catalyst nanoparticles,bimetallic ligand and electronic effects,and the dissolution of unstable Co with the rearrangement of surface structure brought about by acid etching.Furthermore,the accessible raw materials and simplified operating procedures involved in the fabrication process would result in great cost-effectiveness for practical applications of PEMFCs.展开更多
The capabilities of industry, technology, institution and market power form the model of four-capability structure for enterprise＇s sustainable growth. The firm＇s system has the characteristics of dissipative struct...The capabilities of industry, technology, institution and market power form the model of four-capability structure for enterprise＇s sustainable growth. The firm＇s system has the characteristics of dissipative structure. The process of the formation for the sustainable growth capability is one of self-organization operations. The evolution and development of sustainable growth capability is the result of inter-functions and inter-operations among all the sub-systems. On the whole, the current level of sustainable growth capability, the four-capability structure and the random rise-and-fall elements of the external environment determine the direction, speed and level of transition of sustainable growth capability. The self-organization mechanism of the enterprise＇s sustainable growth can be illustrated by the instability of system evolution, the sequence parameter, the potential function and the nonequilibrium phase transition. Chinese firms must pay attention to industry selecting and positioning, technology innovation, institution reform and cultivation of market power, and accelerate the formation of self-organization and effective operation through the dynamic integration and inter-operation of industry, technology, institution and market power. Only in this way can firms cultivate and develop their sustainable growth capability and realize enterprises＇ sustainable growth finally.展开更多
Bimetalic platinum-copper(Pt-Cu)alloy nanowires have emerged as a novel class of fuel cell electrocatalysts for oxygen reduction reaction(ORR)due to their intrinsic high catalytic activity and durability,but preparing...Bimetalic platinum-copper(Pt-Cu)alloy nanowires have emerged as a novel class of fuel cell electrocatalysts for oxygen reduction reaction(ORR)due to their intrinsic high catalytic activity and durability,but preparing such electrocatalysts with clean surface via facile method is still a challenge.Herein,PtCu alloy with nanowire networks(NWNs)structure is obtained by a simple modified polyol method accompanied with a salt-mediated self-assembly process in a water/ethylene glycol(EG)mixing media.The formation mechanism of PtCu NWNs including the morphological evolution and the relevant experimental parameters has been investigated systematically.We propose that a micro-interface in H2O-EG media formed with the assistance of disodium dihydrogen pyrophosphate(Na2H2P2O7)and its unique nature of coordinating with Pt^2+ or Cu^2+ play critical roles in the formation of NWNs.When tested as ORR catalyst,the PtCuNWNs/C exhibits much higher activity and durability than that of PtNWNs/C and commercial PtC,even exceeding the target of DOE in 2020.The excellent performance of PtCuNWNs/C could be attributed to the unique structure of NWNs with 2.4 nm ultrathin wavy nanowires and plentiful surface defects and the modified electronic effect caused by alloying with Cu atoms.展开更多
基金supported by the National Natural Science Foundation of China (32021005, 32272332)the Fundamental Research Funds for the Central Universities (JUSRP622020, JUSRP51501)+1 种基金the Program of Collaborative Innovation Centre of Food Safety and Quality Control in Jiangsu ProvinceWuxi Science and Technology Development Fund Projects (Y20232022)
文摘The number of people travelling to high-altitude areas or participating in mountain sports is increasing.For individuals visiting such terrains for the first time,the lack of adaptation to the hypobaric hypoxic environment can lead to the deterioration of gastrointestinal function and barriers.In more severe cases,this lack of acclimatisation may lead to acute high-altitude illness.At present,the prevention and treatment of these issues primarily revolve around strategies such as descending to lower altitudes,oxygen supplementation,and medication.However,the available intervention measures to prevent health problems resulting from high-altitude environments remain limited.In this review,we discuss common altitude-related illnesses,including gastrointestinal problems.Moreover,we explore the potential of commonly used medications and dietary supplements in alleviating altitude-related issues.This review can provide a basis for future research on modulating the gut microbiota for mitigating high-altitude illness.
文摘To accelerate the kinetics of the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells,ultrafine Pt nanoparticles modified with trace amounts of cobalt were fabricated and decorated on carbon black through a strategy involving modified glycol reduction and chemical etching.The obtained Pt36Co/C catalyst exhibits a much larger electrochemical surface area(ECSA)and an improved ORR electrocatalytic activity compared to commercial Pt/C.Moreover,an electrode prepared with Pt36Co/C was further evaluated under H2-air single cell test conditions,and exhibited a maximum specific power density of 10.27 W mgPt^-1,which is 1.61 times higher than that of a conventional Pt/C electrode and also competitive with most state-of-the-art Pt-based architectures.In addition,the changes in ECSA,power density,and reacting resistance during the accelerated degradation process further demonstrate the enhanced durability of the Pt36Co/C electrode.The superior performance observed in this work can be attributed to the synergy between the ultrasmall size and homogeneous distribution of catalyst nanoparticles,bimetallic ligand and electronic effects,and the dissolution of unstable Co with the rearrangement of surface structure brought about by acid etching.Furthermore,the accessible raw materials and simplified operating procedures involved in the fabrication process would result in great cost-effectiveness for practical applications of PEMFCs.
文摘The capabilities of industry, technology, institution and market power form the model of four-capability structure for enterprise＇s sustainable growth. The firm＇s system has the characteristics of dissipative structure. The process of the formation for the sustainable growth capability is one of self-organization operations. The evolution and development of sustainable growth capability is the result of inter-functions and inter-operations among all the sub-systems. On the whole, the current level of sustainable growth capability, the four-capability structure and the random rise-and-fall elements of the external environment determine the direction, speed and level of transition of sustainable growth capability. The self-organization mechanism of the enterprise＇s sustainable growth can be illustrated by the instability of system evolution, the sequence parameter, the potential function and the nonequilibrium phase transition. Chinese firms must pay attention to industry selecting and positioning, technology innovation, institution reform and cultivation of market power, and accelerate the formation of self-organization and effective operation through the dynamic integration and inter-operation of industry, technology, institution and market power. Only in this way can firms cultivate and develop their sustainable growth capability and realize enterprises＇ sustainable growth finally.
基金the National Major Research Project(No.2018YFB0105601)the National Natural Science Foundation of China(No.21576257)+1 种基金the Natural Science Foundation-Liaoning United Fund(No.U 1508202)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB06050303).
文摘Bimetalic platinum-copper(Pt-Cu)alloy nanowires have emerged as a novel class of fuel cell electrocatalysts for oxygen reduction reaction(ORR)due to their intrinsic high catalytic activity and durability,but preparing such electrocatalysts with clean surface via facile method is still a challenge.Herein,PtCu alloy with nanowire networks(NWNs)structure is obtained by a simple modified polyol method accompanied with a salt-mediated self-assembly process in a water/ethylene glycol(EG)mixing media.The formation mechanism of PtCu NWNs including the morphological evolution and the relevant experimental parameters has been investigated systematically.We propose that a micro-interface in H2O-EG media formed with the assistance of disodium dihydrogen pyrophosphate(Na2H2P2O7)and its unique nature of coordinating with Pt^2+ or Cu^2+ play critical roles in the formation of NWNs.When tested as ORR catalyst,the PtCuNWNs/C exhibits much higher activity and durability than that of PtNWNs/C and commercial PtC,even exceeding the target of DOE in 2020.The excellent performance of PtCuNWNs/C could be attributed to the unique structure of NWNs with 2.4 nm ultrathin wavy nanowires and plentiful surface defects and the modified electronic effect caused by alloying with Cu atoms.
