The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.T...The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.This paper investigates the efects of pore structure and matrix composition on the corrosion behavior and mechanical properties of pure Zn.Porous Zn alloys with varying pore sizes were prepared via vacuum infltration casting.The results showed that addition of Mg elements and an increase in pore size were observed to enhance the strength and elastic modulus of the porous Zn alloy(41.34±0.113 MPa and 0.58±0.02 GPa of the C-Z3AM).However,corrosion tests indicated that specimens with smaller pores and the addition of Mg elements exhibited accelerated corrosion of porous Zn alloys in Hank’s solution.Electrochemical test results show the corrosion resistance rank in order of C-Z5A>C-Z3AM>N-Z5A>N-Z3AM.Additionally,the mechanical retention of porous Zn alloys in simulated body fuids was found to be signifcantly reduced by the incorporation of Mg elements and smaller pore sizes,the yield strength declines rates of C-Z5A,C-Z3AM and N-Z3AM after 30 days of immersion were 16.7%,63.7%and 78.2%,respectively.The objective is to establish the role of the material-structurecorrosion-mechanics relationship,which can provide a theoretical and experimental basis for the design and evaluation of Zn and its alloy implanted devices.展开更多
Mudstone, as a typical soft rock with wide distribution, has been endangering the slopes containing mudstone by its watersensitivity of swelling and weakening strength when encountering water. To comprehensively under...Mudstone, as a typical soft rock with wide distribution, has been endangering the slopes containing mudstone by its watersensitivity of swelling and weakening strength when encountering water. To comprehensively understand the water-sensitivity of mudstone and reveal its infuence on slope stability, we took the working slope containing water-sensitive mudstone of Shengli No.1 open-pit coal mine in Xilinhot, Inner Mongolia, China, as an example. Mudstone samples taken from the working slope were remodeled and saturated, and then triaxial tested to obtain the efective cohesion and efective internal friction angle. The flter paper method was used to obtain the soil–water characteristic curve of unsaturated mudstone. The pore structure of mudstone samples with diferent water contents were analyzed using the mercury intrusion porosimetry tests combined with the fractal dimension. The total pore content of the mudstone sample with lower water content is greater than that of the mudstone sample with higher water content. The mesopores are more in the mudstone sample with lower water content, while the small pores are more in the mudstone sample with higher water content. The variation of water content will change the complexity of mudstone pore structure. The higher the water content, the simpler the mudstone pore structure and the smoother the pore surface. Numerical calculations were conducted on the stability of the working slope under diferent rainfall conditions. The efective saturation on the mudstone layer surface changed and the plastic strain all occurred on the mudstone steps under diferent rainfall conditions. The key to preventing landslide of the slope containing water-sensitive mudstone in Shengli No.1 open-pit coal mine is to control the deformation and sliding of the mudstone layer.展开更多
Rubber plantations have increased signifcantly under unprecedented economic growth in tropical areas,which leads to soil degradation and thereby alters soil hydrological processes.However,our understanding of how fore...Rubber plantations have increased signifcantly under unprecedented economic growth in tropical areas,which leads to soil degradation and thereby alters soil hydrological processes.However,our understanding of how forest conversion affects soil hydrological processes remains unclear.Here,we collected soil samples from secondary forests(SF)and rubber plantations(RP)to determine the soil hydrological characteristics.We found the topsoil(0-20 cm)water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer(20-60 cm).Meanwhile,the soil infltration rates among the two vegetation types decreased signifcantly with infltration time,with higher stable soil infltration rates in SF than those in RP.Moreover,soil properties were also impacted by the forest conversion,such as the topsoil capillary porosity(CP)and total porosity(TP)in SF were higher than those of RP but contrasted in a deep soil layer.In comparison,the topsoil bulk density(BD)in SF was lower than that of RP,but contrasted in the deep soil layer and reached a signifcant level in the 0-10 and 40-50 cm(P<0.05).Overall,the soil water retention was mainly determined by the CP,which could explain 31.56%of the total variance in soil water retention,followed by TP(26.57%)and soil BD(26.47%),whereas soil texture exerts a weak effect on soil water retention.Therefore,we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infltration rates.展开更多
基金supported by the Shaanxi Qinchuangyuan Cited High-level Innovation and Entrepreneurial Talents Project(Nos.QCYRCXM-2022-156,QCYRCXM-2022-52,QCYRCXM-2023-181)the Fundamental Research Funds for the Central Universities(N2225010)+2 种基金the Yingkou Enterprise Doctoral Innovation and Entrepreneurship Plan(YKSCJH2023-007)the Natural Science Basic Research Program of Shaanxi Province(2023-JC-QN-0378,2023-YBSF-561)the Shaanxi Provincial Key R&D Program(2024SF-YBXM-442).
文摘The complex stresses experienced by medical-grade porous metals in the physiological environment following implantation as bone repair materials necessitate a comprehensive understanding of their mechanical behavior.This paper investigates the efects of pore structure and matrix composition on the corrosion behavior and mechanical properties of pure Zn.Porous Zn alloys with varying pore sizes were prepared via vacuum infltration casting.The results showed that addition of Mg elements and an increase in pore size were observed to enhance the strength and elastic modulus of the porous Zn alloy(41.34±0.113 MPa and 0.58±0.02 GPa of the C-Z3AM).However,corrosion tests indicated that specimens with smaller pores and the addition of Mg elements exhibited accelerated corrosion of porous Zn alloys in Hank’s solution.Electrochemical test results show the corrosion resistance rank in order of C-Z5A>C-Z3AM>N-Z5A>N-Z3AM.Additionally,the mechanical retention of porous Zn alloys in simulated body fuids was found to be signifcantly reduced by the incorporation of Mg elements and smaller pore sizes,the yield strength declines rates of C-Z5A,C-Z3AM and N-Z3AM after 30 days of immersion were 16.7%,63.7%and 78.2%,respectively.The objective is to establish the role of the material-structurecorrosion-mechanics relationship,which can provide a theoretical and experimental basis for the design and evaluation of Zn and its alloy implanted devices.
基金supported by the National Key R&D Program of China(2022YFC2903902)the National Natural Science Foundation of China(51974295).
文摘Mudstone, as a typical soft rock with wide distribution, has been endangering the slopes containing mudstone by its watersensitivity of swelling and weakening strength when encountering water. To comprehensively understand the water-sensitivity of mudstone and reveal its infuence on slope stability, we took the working slope containing water-sensitive mudstone of Shengli No.1 open-pit coal mine in Xilinhot, Inner Mongolia, China, as an example. Mudstone samples taken from the working slope were remodeled and saturated, and then triaxial tested to obtain the efective cohesion and efective internal friction angle. The flter paper method was used to obtain the soil–water characteristic curve of unsaturated mudstone. The pore structure of mudstone samples with diferent water contents were analyzed using the mercury intrusion porosimetry tests combined with the fractal dimension. The total pore content of the mudstone sample with lower water content is greater than that of the mudstone sample with higher water content. The mesopores are more in the mudstone sample with lower water content, while the small pores are more in the mudstone sample with higher water content. The variation of water content will change the complexity of mudstone pore structure. The higher the water content, the simpler the mudstone pore structure and the smoother the pore surface. Numerical calculations were conducted on the stability of the working slope under diferent rainfall conditions. The efective saturation on the mudstone layer surface changed and the plastic strain all occurred on the mudstone steps under diferent rainfall conditions. The key to preventing landslide of the slope containing water-sensitive mudstone in Shengli No.1 open-pit coal mine is to control the deformation and sliding of the mudstone layer.
基金supported by the Hainan Province South China Sea New Star Science and Technology Innovation Talent Platform Project(NHXXRCXM202303)National Natural Science Foundation of China(42207524)+2 种基金Hainan Provincial Natural Science Foundation of China(422QN264 and 423MS117)Key R&D Program of Hainan(ZDYF2022SHFZ042)start-up funding from Hainan University(KYQD(ZR)-22085).
文摘Rubber plantations have increased signifcantly under unprecedented economic growth in tropical areas,which leads to soil degradation and thereby alters soil hydrological processes.However,our understanding of how forest conversion affects soil hydrological processes remains unclear.Here,we collected soil samples from secondary forests(SF)and rubber plantations(RP)to determine the soil hydrological characteristics.We found the topsoil(0-20 cm)water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer(20-60 cm).Meanwhile,the soil infltration rates among the two vegetation types decreased signifcantly with infltration time,with higher stable soil infltration rates in SF than those in RP.Moreover,soil properties were also impacted by the forest conversion,such as the topsoil capillary porosity(CP)and total porosity(TP)in SF were higher than those of RP but contrasted in a deep soil layer.In comparison,the topsoil bulk density(BD)in SF was lower than that of RP,but contrasted in the deep soil layer and reached a signifcant level in the 0-10 and 40-50 cm(P<0.05).Overall,the soil water retention was mainly determined by the CP,which could explain 31.56%of the total variance in soil water retention,followed by TP(26.57%)and soil BD(26.47%),whereas soil texture exerts a weak effect on soil water retention.Therefore,we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infltration rates.
