Table_2_Health damage assessment of commuters and staff in the metro system based on field monitoring—A case study of Nanjing.DOCX

IntroductionThe metro has emerged as a major mode of transportation. A significant number of commuters and staff in the metro system are exposed to air pollutants because of its shielded environment, and substantial health damage requires quantitative assessment. Previous studies have focused on comparing the health impacts among different transportation modes, overlooking the specific population characteristics and pollutant distribution in metro systems.MethodsTo make improvements, this study implements field monitoring of the metro's air environment utilizing specialized instruments and develops a health damage assessment model. The model quantifies health damage of two main groups (commuters and staff) in metro systems at three different areas (station halls, platforms, and metro cabins) due to particulate matter 10 and benzene series pollution.ConclusionA case study of Nanjing Metro Line 3 was conducted to demonstrate the applicability of the model. Health damage at different metro stations was analyzed, and the health damage of commuters and staff was assessed and compared. This study contributes to enhancing research on health damage in the metro systems by providing a reference for mitigation measures and guiding health subsidy policies.</p

Table_1_Health damage assessment of commuters and staff in the metro system based on field monitoring—A case study of Nanjing.DOCX

IntroductionThe metro has emerged as a major mode of transportation. A significant number of commuters and staff in the metro system are exposed to air pollutants because of its shielded environment, and substantial health damage requires quantitative assessment. Previous studies have focused on comparing the health impacts among different transportation modes, overlooking the specific population characteristics and pollutant distribution in metro systems.MethodsTo make improvements, this study implements field monitoring of the metro's air environment utilizing specialized instruments and develops a health damage assessment model. The model quantifies health damage of two main groups (commuters and staff) in metro systems at three different areas (station halls, platforms, and metro cabins) due to particulate matter 10 and benzene series pollution.ConclusionA case study of Nanjing Metro Line 3 was conducted to demonstrate the applicability of the model. Health damage at different metro stations was analyzed, and the health damage of commuters and staff was assessed and compared. This study contributes to enhancing research on health damage in the metro systems by providing a reference for mitigation measures and guiding health subsidy policies.</p

Metallic Bond-Enabled Wetting Behavior at the Liquid Ga/CuGa₂ Interfaces

Interface interaction can strongly modify contact angle, adsorption energy, interfacial tension, and composition of the contact area. In particular, the interfaces between gallium-based liquid metal (LM) and its intermetallic layer present many mysterious and peculiar wetting phenomena, which have not been fully realized up to now. Here in this study, we found that a gallium-based liquid metal droplet can quickly transform into a puddle on the CuGa₂ surface through a spreading–wetting procedure. The mechanism lying behind this phenomenon can be ascribed to the formation of an intermetallic CuGa₂ on Cu plate surface, which provides a stable metallic bond to induce the wetting behavior. For a quantitative evaluation of the interface force, a metallic bond-enabled wetting model is established on the basis of the density functional theory. The first-principles density functional calculations are then performed to examine the work function, density of states, and adsorption energy. The predicted results show that the work function of CuGa₂ (010) is approximately 4.47 eV, which is very comparable with that of pure liquid Ga (4.32 eV). This indicates that the valence electrons between Ga and CuGa₂ slab can exchange easily, which consequently leads to the strong valence electron hybridization and metallic bond. In addition, the adsorption energy of a single Ga atom on CuGa₂ (010) slab has a larger value than In and Sn. The tested metallic bond wetting force at the interface is proportional to the average adsorption energy of the gallium-based LM adatom, and increases with the rising content of gallium. The simulation results demonstrate excellent consistency with the experimental data in this work

Metallic Bond-Enabled Wetting Behavior at the Liquid Ga/CuGa₂ Interfaces

Interface interaction can strongly modify contact angle, adsorption energy, interfacial tension, and composition of the contact area. In particular, the interfaces between gallium-based liquid metal (LM) and its intermetallic layer present many mysterious and peculiar wetting phenomena, which have not been fully realized up to now. Here in this study, we found that a gallium-based liquid metal droplet can quickly transform into a puddle on the CuGa₂ surface through a spreading–wetting procedure. The mechanism lying behind this phenomenon can be ascribed to the formation of an intermetallic CuGa₂ on Cu plate surface, which provides a stable metallic bond to induce the wetting behavior. For a quantitative evaluation of the interface force, a metallic bond-enabled wetting model is established on the basis of the density functional theory. The first-principles density functional calculations are then performed to examine the work function, density of states, and adsorption energy. The predicted results show that the work function of CuGa₂ (010) is approximately 4.47 eV, which is very comparable with that of pure liquid Ga (4.32 eV). This indicates that the valence electrons between Ga and CuGa₂ slab can exchange easily, which consequently leads to the strong valence electron hybridization and metallic bond. In addition, the adsorption energy of a single Ga atom on CuGa₂ (010) slab has a larger value than In and Sn. The tested metallic bond wetting force at the interface is proportional to the average adsorption energy of the gallium-based LM adatom, and increases with the rising content of gallium. The simulation results demonstrate excellent consistency with the experimental data in this work

Metallic Bond-Enabled Wetting Behavior at the Liquid Ga/CuGa₂ Interfaces

Interface interaction can strongly modify contact angle, adsorption energy, interfacial tension, and composition of the contact area. In particular, the interfaces between gallium-based liquid metal (LM) and its intermetallic layer present many mysterious and peculiar wetting phenomena, which have not been fully realized up to now. Here in this study, we found that a gallium-based liquid metal droplet can quickly transform into a puddle on the CuGa₂ surface through a spreading–wetting procedure. The mechanism lying behind this phenomenon can be ascribed to the formation of an intermetallic CuGa₂ on Cu plate surface, which provides a stable metallic bond to induce the wetting behavior. For a quantitative evaluation of the interface force, a metallic bond-enabled wetting model is established on the basis of the density functional theory. The first-principles density functional calculations are then performed to examine the work function, density of states, and adsorption energy. The predicted results show that the work function of CuGa₂ (010) is approximately 4.47 eV, which is very comparable with that of pure liquid Ga (4.32 eV). This indicates that the valence electrons between Ga and CuGa₂ slab can exchange easily, which consequently leads to the strong valence electron hybridization and metallic bond. In addition, the adsorption energy of a single Ga atom on CuGa₂ (010) slab has a larger value than In and Sn. The tested metallic bond wetting force at the interface is proportional to the average adsorption energy of the gallium-based LM adatom, and increases with the rising content of gallium. The simulation results demonstrate excellent consistency with the experimental data in this work

Metallic Bond-Enabled Wetting Behavior at the Liquid Ga/CuGa₂ Interfaces

Interface interaction can strongly modify contact angle, adsorption energy, interfacial tension, and composition of the contact area. In particular, the interfaces between gallium-based liquid metal (LM) and its intermetallic layer present many mysterious and peculiar wetting phenomena, which have not been fully realized up to now. Here in this study, we found that a gallium-based liquid metal droplet can quickly transform into a puddle on the CuGa₂ surface through a spreading–wetting procedure. The mechanism lying behind this phenomenon can be ascribed to the formation of an intermetallic CuGa₂ on Cu plate surface, which provides a stable metallic bond to induce the wetting behavior. For a quantitative evaluation of the interface force, a metallic bond-enabled wetting model is established on the basis of the density functional theory. The first-principles density functional calculations are then performed to examine the work function, density of states, and adsorption energy. The predicted results show that the work function of CuGa₂ (010) is approximately 4.47 eV, which is very comparable with that of pure liquid Ga (4.32 eV). This indicates that the valence electrons between Ga and CuGa₂ slab can exchange easily, which consequently leads to the strong valence electron hybridization and metallic bond. In addition, the adsorption energy of a single Ga atom on CuGa₂ (010) slab has a larger value than In and Sn. The tested metallic bond wetting force at the interface is proportional to the average adsorption energy of the gallium-based LM adatom, and increases with the rising content of gallium. The simulation results demonstrate excellent consistency with the experimental data in this work

Multifunctional Stiff Carbon Foam Derived from Bread

The creation of stiff yet multifunctional three-dimensional porous carbon architecture at very low cost is still challenging. In this work, lightweight and stiff carbon foam (CF) with adjustable pore structure was prepared by using flour as the basic element via a simple fermentation and carbonization process. The compressive strength of CF exhibits a high value of 3.6 MPa whereas its density is 0.29 g/cm³ (compressive modulus can be 121 MPa). The electromagnetic interference (EMI) shielding effectiveness measurements (specific EMI shielding effectiveness can be 78.18 dB·cm³·g^–1) indicate that CF can be used as lightweight, effective shielding material. Unlike ordinary foam structure materials, the low thermal conductivity (lowest is 0.06 W/m·K) with high resistance to fire makes CF a good candidate for commercial thermal insulation material. These results demonstrate a promising method to fabricate an economical, robust carbon material for applications in industry as well as topics regarding environmental protection and improvement of energy efficiency

Stiff, Thermally Stable and Highly Anisotropic Wood-Derived Carbon Composite Monoliths for Electromagnetic Interference Shielding

Electromagnetic interference (EMI) shielding materials for electronic devices in aviation and aerospace not only need lightweight and high shielding effectiveness, but also should withstand harsh environments. Traditional EMI shielding materials often show heavy weight, poor thermal stability, short lifetime, poor tolerance to chemicals, and are hard-to-manufacture. Searching for high-efficiency EMI shielding materials overcoming the above weaknesses is still a great challenge. Herein, inspired by the unique structure of natural wood, lightweight and highly anisotropic wood-derived carbon composite EMI shielding materials have been prepared which possess not only high EMI shielding performance and mechanical stable characteristics, but also possess thermally stable properties, outperforming those metals, conductive polymers, and their composites. The newly developed low-cost materials are promising for specific applications in aerospace electronic devices, especially regarding extreme temperatures