The Sr/F co-doped CaP(Sr/F-CaP)coatings were prepared by micro-arc oxidation(MAO)under different voltages to modify the microstructure and corrosion behavior of Mg-4Zn-1Mn alloy.The surface and interface characteristi...The Sr/F co-doped CaP(Sr/F-CaP)coatings were prepared by micro-arc oxidation(MAO)under different voltages to modify the microstructure and corrosion behavior of Mg-4Zn-1Mn alloy.The surface and interface characteristics investigated using scanning electron microscopy(SEM)and energy dispersive X-ray spectrometer(EDS)showed that the MAO coatings displayed uneven crater-like holes and tiny cracks under lower voltage,while they exhibited relatively homogeneous crater-like holes without cracks under higher voltage.The thickness of MAO coatings increased with increasing voltage.The corrosion behavior of Mg-4Zn-1Mn alloy was improved by the MAO coatings.The MAO coatings prepared under 450 V and 500 V voltages possessed the best corrosion resistance with regard to the electrochemical corrosion tests and immersion corrosion tests,respectively.The MAO coatings fabricated under 450-500 V could provide a better corrosion protection effect for the substrate.展开更多
This paper"Detecting gravitational wave with an interferometric seismometer array on lunar nearside"[1]was published in SCIENCE CHINA Physics,Mechanics&Astronomy(66,109513(2023),doi:10.1007/s11433-023-21...This paper"Detecting gravitational wave with an interferometric seismometer array on lunar nearside"[1]was published in SCIENCE CHINA Physics,Mechanics&Astronomy(66,109513(2023),doi:10.1007/s11433-023-2179-9).Due to an oversight on our part,some errors were made in the originally published paper.We apologize for these errors and offer the corresponding explanations and corrections for the readers.展开更多
Our Moon is by far the easiest natural, extraterrestrial celestial object for us to reach, and many space agencies, in particular the China National Space Administration, have publicized plans for manned missions ther...Our Moon is by far the easiest natural, extraterrestrial celestial object for us to reach, and many space agencies, in particular the China National Space Administration, have publicized plans for manned missions there. Such high-profile projects must yield commensurate scientific outputs to justify their cost to the taxpayers. An important criterion for the selection of candidate experiments is the extent to which the Moon plays an integral and irreplaceable role, as opposed to offering only marginal advantages over Earth-orbit, space-based alternatives. In this study, we propose an experiment that excels in this regard, which considers the Moon as part of the experimental apparatus. Specifically, the Moon acts as a Weber bar-style resonant mass that responds to deci-Hertz gravitational waves(GWs). GW-excited lunar vibrations can be picked up by an array of(prefabricated on Earth and easy to transport to the Moon) small laser interferometric seismometers yielding GW detection. Such a setup would plug a gap in the GW frequency range already covered by the existing or underdevelopment detectors, and it can inform us on important astrophysics topics, such as the progenitors of Type Ia supernovae(SNe Ia) or intermediate mass black holes. We provide the instrument design as well as its deployment strategy, and we also summarize relevant science cases according to the estimated viable sensitivity.展开更多
As one of the most promising fixators developed for anterior cruciate ligament(ACL)reconstruction,biodegradable magnesium(Mg)-based interference screws have gained increasing attention attributed to their appropriate ...As one of the most promising fixators developed for anterior cruciate ligament(ACL)reconstruction,biodegradable magnesium(Mg)-based interference screws have gained increasing attention attributed to their appropriate modulus and favorable biological properties during degradation after surgical insertion.However,its fast degradation and insufficient mechanical strength have also been recognized as one of the major causes to limit their further application clinically.This review focused on the following four parts.Firstly,the advantages of Mg or its alloys over their counterparts as orthopaedic implants in the fixation of tendon grafts in ACL reconstruction were discussed.Subsequently,the underlying mechanisms behind the contributions of Mg ions to the tendon-bone healing were introduced.Thirdly,the technical challenges of Mg-based interference screws towards clinical trials were discussed,which was followed by the introduction of currently used modification methods for gaining improved corrosion resistance and mechanical properties.Finally,novel strategies including development of Mg/Titanium(Ti)hybrid fixators and Mg-based screws with innovative structure for achieving clinically customized therapies were proposed.Collectively,the advancements in the basic and translational research on the Mg-based interference screws may lay the foundation for exploring a new era in the treatment of the tendon-bone insertion(TBI)and related disorders.展开更多
文摘The Sr/F co-doped CaP(Sr/F-CaP)coatings were prepared by micro-arc oxidation(MAO)under different voltages to modify the microstructure and corrosion behavior of Mg-4Zn-1Mn alloy.The surface and interface characteristics investigated using scanning electron microscopy(SEM)and energy dispersive X-ray spectrometer(EDS)showed that the MAO coatings displayed uneven crater-like holes and tiny cracks under lower voltage,while they exhibited relatively homogeneous crater-like holes without cracks under higher voltage.The thickness of MAO coatings increased with increasing voltage.The corrosion behavior of Mg-4Zn-1Mn alloy was improved by the MAO coatings.The MAO coatings prepared under 450 V and 500 V voltages possessed the best corrosion resistance with regard to the electrochemical corrosion tests and immersion corrosion tests,respectively.The MAO coatings fabricated under 450-500 V could provide a better corrosion protection effect for the substrate.
文摘This paper"Detecting gravitational wave with an interferometric seismometer array on lunar nearside"[1]was published in SCIENCE CHINA Physics,Mechanics&Astronomy(66,109513(2023),doi:10.1007/s11433-023-2179-9).Due to an oversight on our part,some errors were made in the originally published paper.We apologize for these errors and offer the corresponding explanations and corrections for the readers.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.310432103)the National Natural Science Foundation of China(Grant Nos.12073005,12021003,12021003,11920101003,and 11633001)+1 种基金the Interdiscipline Research Funds of Beijing Normal Universitythe Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23000000)。
文摘Our Moon is by far the easiest natural, extraterrestrial celestial object for us to reach, and many space agencies, in particular the China National Space Administration, have publicized plans for manned missions there. Such high-profile projects must yield commensurate scientific outputs to justify their cost to the taxpayers. An important criterion for the selection of candidate experiments is the extent to which the Moon plays an integral and irreplaceable role, as opposed to offering only marginal advantages over Earth-orbit, space-based alternatives. In this study, we propose an experiment that excels in this regard, which considers the Moon as part of the experimental apparatus. Specifically, the Moon acts as a Weber bar-style resonant mass that responds to deci-Hertz gravitational waves(GWs). GW-excited lunar vibrations can be picked up by an array of(prefabricated on Earth and easy to transport to the Moon) small laser interferometric seismometers yielding GW detection. Such a setup would plug a gap in the GW frequency range already covered by the existing or underdevelopment detectors, and it can inform us on important astrophysics topics, such as the progenitors of Type Ia supernovae(SNe Ia) or intermediate mass black holes. We provide the instrument design as well as its deployment strategy, and we also summarize relevant science cases according to the estimated viable sensitivity.
基金This work was supported by the National Natural Science Foundation of China(Ref No.81702165)Guangdong Natural Science Fund(Ref.No.2019A1515011404)+1 种基金Key-Area Research and Development Program of Guangdong Province(Ref.No.2020B090924004)Theme-based Research Scheme(Ref No.T13-402/17-N).
文摘As one of the most promising fixators developed for anterior cruciate ligament(ACL)reconstruction,biodegradable magnesium(Mg)-based interference screws have gained increasing attention attributed to their appropriate modulus and favorable biological properties during degradation after surgical insertion.However,its fast degradation and insufficient mechanical strength have also been recognized as one of the major causes to limit their further application clinically.This review focused on the following four parts.Firstly,the advantages of Mg or its alloys over their counterparts as orthopaedic implants in the fixation of tendon grafts in ACL reconstruction were discussed.Subsequently,the underlying mechanisms behind the contributions of Mg ions to the tendon-bone healing were introduced.Thirdly,the technical challenges of Mg-based interference screws towards clinical trials were discussed,which was followed by the introduction of currently used modification methods for gaining improved corrosion resistance and mechanical properties.Finally,novel strategies including development of Mg/Titanium(Ti)hybrid fixators and Mg-based screws with innovative structure for achieving clinically customized therapies were proposed.Collectively,the advancements in the basic and translational research on the Mg-based interference screws may lay the foundation for exploring a new era in the treatment of the tendon-bone insertion(TBI)and related disorders.
