Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms ...Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.展开更多
Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of t...Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of the sum of three principal strains was deduced to quantitatively investigate the infrared radiation characteristics in test. Two typical specimens,the three-point bending beam and the disc pressed in diameter,were tested and their principal strains were calculated by finite element method in order to obtain the temperature differences of infrared radiation. Numerical results are in a good agreement with test results,which verifies the validity of the formula of calculating temperature differences of infrared radiation and the model of quantitatively describing the infrared radiation characteristics of solid materials,and reveals the corresponding inner physical mechanism.展开更多
基金Projects(2019NY-200,2020ZDLNY06-06,2020ZDLNY07-10)supported by the Key Research and Development Program of Shaanxi Province,ChinaProject(2019YFC1803604)supported by the National Key Research and Development Program of China。
文摘Lead(Pb)and zinc(Zn)are widely recognized as common environmental contaminants,contributing to soil degradation and posing risks to environmental health.Combining functional carbon-based materials with microorganisms has been considered as an effective and environmentally friendly strategy for remediating Pb/Zn-contaminated soil.However,there is still a lack of understanding the connection between heavy metal immobilization and plant responses,which hampers practical applications.Here,a 90-day pot experiment was conducted to investigate the integrated effects of biochar(WS700)and microorganisms including inorganic phosphate-solubilizing bacteria(IPSB)and sulfate reducing bacteria(SRB)on Pb and Zn synchronous immobilization and the physiological responses of Brassica rapa var.chinensis(Brassica).Compared with CK,bacteria-loaded biochar treatment declined the exchangeable Pb and Zn fraction by 94.69%−98.37%and 94.55%−99.52%,while increasing the residual state Pb and Zn by 75.50%−208.58%and 96.71%−110.85%,respectively.Three amendments enhanced Brassica growth by improving total chlorophyll content and superoxide dismutase(SOD)and peroxidase(POD)activities.The bacteria-loaded biochar treatment effectively regulated stomatal conductance and reduced intercellular CO_(2) concentration.Moreover,compared with CK,three amendments reduced MDA content by 28.84%,28.30%and 41.60%,respectively,under the high concentration of Pb and Zn.The findings demonstrated the significant role of bacterial-biochar consortia in immobilizing Pb and Zn and mitigating Pb and Zn-induced stress in plants by regulating photosynthetic characteristics and antioxidant enzyme activities.
基金Projects (10775018, 10702010, 50374073) supported by the National Natural Science Foundation of ChinaProject(2002CB412701) supported by the National Basic Research Program of China
文摘Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of the sum of three principal strains was deduced to quantitatively investigate the infrared radiation characteristics in test. Two typical specimens,the three-point bending beam and the disc pressed in diameter,were tested and their principal strains were calculated by finite element method in order to obtain the temperature differences of infrared radiation. Numerical results are in a good agreement with test results,which verifies the validity of the formula of calculating temperature differences of infrared radiation and the model of quantitatively describing the infrared radiation characteristics of solid materials,and reveals the corresponding inner physical mechanism.
