Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffo...Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.展开更多
The half metallic character in double perovskites makes them highly sought-after materials for the use in spintronics applications.Spintronic devices can operate at far higher speeds with less power consumption which ...The half metallic character in double perovskites makes them highly sought-after materials for the use in spintronics applications.Spintronic devices can operate at far higher speeds with less power consumption which has the potential to eventually replace traditional electronics.In this manuscript,we theoretically investigated the physical properties of europium based double perovskites Eu_(2)XWO_(6)(X=Mg,Zn).The volume optimization was done for both compounds,which demonstrate complete structural stability,while their thermodynamic stability is confirmed through the calculated formation energies.The mechanical properties reveal that both studied compounds fulfill the Born's stability criteria.The electronic properties of Eu_(2)MgWO_(6)and Eu_(2)ZnWO_(6)reveal that in spin up channel both materials exhibit metallic character,while in spin down channel,indirect band gaps of 4.11 and 3.97 eV are noticed for Eu_(2)MgWO_(6)and Eu_(2)ZnWO_(6),respectively,showing half-metallic behavior.The examination of the magnetic properties shows a significant magnetic moment of 14μ_(B)for Eu_(2)XWO_(6)(X=Mg,Zn).High optical conductivity and absorption are noticed in the UV region as shown by the optical traits of Eu_(2)XWO_(6)(X=Mg,Zn).Both materials show high magnetic moments,which leads to high spin polarization and are considered highly effective for the functioning of spintronic devices.展开更多
The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and dire...The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties： it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the fight eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modem birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 （3）： 265-276, 2010].展开更多
The Changjiang （Yangtze） estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions. Distributions of heavy metals show typical banded diffusion pattern, with high co...The Changjiang （Yangtze） estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions. Distributions of heavy metals show typical banded diffusion pattern, with high concentrations near the river mouth and following a decreasing trend in the offshore direction. According to chemical fractions, Fe/Mn oxide fraction is the major non-residual fraction in the Changjiang estuarine and offshore sediments, Higher percentage of non-residual fraction of Pb implies that, the industrial contaminations transported via the atmosphere and river input, may affect the non-residual fraction of heavy metals. Over past fifteen years, the concentration of Pb normalizing to A1 presents significant increasing trend, corresponding to the effect of human activities. By comparison of heavy metals fractions in 2003 to 2006, it has been realized that increasing water and sediment may cause a higher percentage non-residual fraction of Cu in the southern part of offshore muddy sediments.展开更多
An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculati...An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).展开更多
文摘Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.
基金financially supported by Ongoing Research Funding Program,(ORF-2025-445),King Saud University,Riyadh,Saudi Arabia。
文摘The half metallic character in double perovskites makes them highly sought-after materials for the use in spintronics applications.Spintronic devices can operate at far higher speeds with less power consumption which has the potential to eventually replace traditional electronics.In this manuscript,we theoretically investigated the physical properties of europium based double perovskites Eu_(2)XWO_(6)(X=Mg,Zn).The volume optimization was done for both compounds,which demonstrate complete structural stability,while their thermodynamic stability is confirmed through the calculated formation energies.The mechanical properties reveal that both studied compounds fulfill the Born's stability criteria.The electronic properties of Eu_(2)MgWO_(6)and Eu_(2)ZnWO_(6)reveal that in spin up channel both materials exhibit metallic character,while in spin down channel,indirect band gaps of 4.11 and 3.97 eV are noticed for Eu_(2)MgWO_(6)and Eu_(2)ZnWO_(6),respectively,showing half-metallic behavior.The examination of the magnetic properties shows a significant magnetic moment of 14μ_(B)for Eu_(2)XWO_(6)(X=Mg,Zn).High optical conductivity and absorption are noticed in the UV region as shown by the optical traits of Eu_(2)XWO_(6)(X=Mg,Zn).Both materials show high magnetic moments,which leads to high spin polarization and are considered highly effective for the functioning of spintronic devices.
基金supported by the Deutsche Forschungsgemeinschaftthe Human Frontiers Sciences Program
文摘The avian magnetic compass was analyzed in bird species of three different orders - Passeriforms, Columbiforms and Galliforms - and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties： it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the fight eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modem birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 （3）： 265-276, 2010].
基金The National Natural Science Foundation of China under contract No.41076022the National Basic Research Program of China under contract No.2002CB412400
文摘The Changjiang （Yangtze） estuarine and offshore sediments were analyzed for total heavy metals concentrations and chemical fractions. Distributions of heavy metals show typical banded diffusion pattern, with high concentrations near the river mouth and following a decreasing trend in the offshore direction. According to chemical fractions, Fe/Mn oxide fraction is the major non-residual fraction in the Changjiang estuarine and offshore sediments, Higher percentage of non-residual fraction of Pb implies that, the industrial contaminations transported via the atmosphere and river input, may affect the non-residual fraction of heavy metals. Over past fifteen years, the concentration of Pb normalizing to A1 presents significant increasing trend, corresponding to the effect of human activities. By comparison of heavy metals fractions in 2003 to 2006, it has been realized that increasing water and sediment may cause a higher percentage non-residual fraction of Cu in the southern part of offshore muddy sediments.
文摘An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).
