Soil spatial information has traditionally been presented as polygon maps at coarse scales. Solving global and local issues, including food security, water regulation, land degradation, and climate change requires hig...Soil spatial information has traditionally been presented as polygon maps at coarse scales. Solving global and local issues, including food security, water regulation, land degradation, and climate change requires higher quality, more consistent and detailed soil information. Accurate prediction of soil variation over large and complex areas with limited samples remains a challenge, which is especially significant for China due to its vast land area which contains the most diverse soil landscapes in the world. Here, we integrated predictive soil mapping paradigm with adaptive depth function fitting, state-of-the-art ensemble machine learning and high-resolution soil-forming environment characterization in a highperformance parallel computing environment to generate 90-m resolution national gridded maps of nine soil properties(pH, organic carbon, nitrogen, phosphorus, potassium, cation exchange capacity, bulk density, coarse fragments, and thickness) at multiple depths across China. This was based on approximately5000 representative soil profiles collected in a recent national soil survey and a suite of detailed covariates to characterize soil-forming environments. The predictive accuracy ranged from very good to moderate(Model Efficiency Coefficients from 0.71 to 0.36) at 0–5 cm. The predictive accuracy for most soil properties declined with depth. Compared with previous soil maps, we achieved significantly more detailed and accurate predictions which could well represent soil variations across the territory and are a significant contribution to the GlobalSoilMap.net project. The relative importance of soil-forming factors in the predictions varied by specific soil property and depth, suggesting the complexity and non-stationarity of comprehensive multi-factor interactions in the process of soil development.展开更多
′In this article, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved （G′/G）-expansion func...′In this article, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved （G′/G）-expansion function method to calculate the exact solutions to the time- and space-fractional derivative foam drainage equation and the time- and space-fractional derivative nonlinear KdV equation. This method is efficient and powerful for solving wide classes of nonlinear evolution fractional order equations.展开更多
In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's...In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's function is constructed.This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface.Then,the problem is divided into an upper and lower half space along the horizontal interface,regarded as a harmony model.In order to satisfy the integral continuity condition, the unknown anti-plane forces are applied to the interface.The integral equations with unknown forces can be established through the continuity condition,and after transformation,the algebraic equations are solved numerically.Finally,the distribution of the dynamic stress concentration factor(DSCF)around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.展开更多
In this paper, antiplane response of an isosceles triangular hill to incident SH waves is studied based on the method of complex function and by using moving coordinate system. The standing wave function, which can sa...In this paper, antiplane response of an isosceles triangular hill to incident SH waves is studied based on the method of complex function and by using moving coordinate system. The standing wave function, which can satisfy the governing equation and boundary condition, is provided. Furthermore, numerical examples are presented; the influences of wave number and angle of the incident waves and the angle of the hill’s peak on ground motion are discussed.展开更多
In the peripheral nervous system,the activation of Sirtuin 1 can improve insulin resistance;however,the role played by Sirtuin 1 in the central nervous system remains unknown.In this study,rat models of diabetes melli...In the peripheral nervous system,the activation of Sirtuin 1 can improve insulin resistance;however,the role played by Sirtuin 1 in the central nervous system remains unknown.In this study,rat models of diabetes mellitus were generated by a single injection of streptozotocin.At 8 weeks after streptozotocin injection,the Morris water maze test and western blot assays confirmed that the diabetic model rats had learning and memory deficits,insulin resistance,and Sirtuin 1 expression could be detected in the hippocampus.Insulin and the insulin receptor inhibitor S961 were intranasally administered to investigate the regulatory effects of insulin signaling on Sirtuin 1.The results showed that insulin administration improved the impaired cognitive function of diabetic model rats and increased the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1 in the hippocampus.Conversely,S961 administration resulted in more severe cognitive dysfunction and reduced the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1.The Sirtuin 1 activator SRT2104 and the inhibitor Sirtinol were injected into the lateral ventricle,which revealed that the activation of Sirtuin 1 increased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor.Hippocampal dendritic length and spine density also increased in response to Sirtuin 1 activation.In contrast,Sirtinol decreased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor and damaged the dendritic structure.These findings suggest that the Sirtuin 1 signaling pathway plays an important role in the development of insulin resistance-related cognitive deficits in diabetic rats.This study was approved by the Animal Ethics Welfare Committee of the First Affiliated Hospital of Hunan University of Chinese Med展开更多
基金the National Key Basic Research Special Foundation of China(2008FY110600 and 2014FY110200)the National Natural Science Foundation of China(41930754 and42071072)+1 种基金the 2nd Comprehensive Scientific Survey of the Qinghai-Tibet Plateau(2019QZKK0306)the Project of “OneThree-Five”Strategic Planning&Frontier Sciences of the Institute of Soil Science,Chinese Academy of Sciences(ISSASIP1622)。
文摘Soil spatial information has traditionally been presented as polygon maps at coarse scales. Solving global and local issues, including food security, water regulation, land degradation, and climate change requires higher quality, more consistent and detailed soil information. Accurate prediction of soil variation over large and complex areas with limited samples remains a challenge, which is especially significant for China due to its vast land area which contains the most diverse soil landscapes in the world. Here, we integrated predictive soil mapping paradigm with adaptive depth function fitting, state-of-the-art ensemble machine learning and high-resolution soil-forming environment characterization in a highperformance parallel computing environment to generate 90-m resolution national gridded maps of nine soil properties(pH, organic carbon, nitrogen, phosphorus, potassium, cation exchange capacity, bulk density, coarse fragments, and thickness) at multiple depths across China. This was based on approximately5000 representative soil profiles collected in a recent national soil survey and a suite of detailed covariates to characterize soil-forming environments. The predictive accuracy ranged from very good to moderate(Model Efficiency Coefficients from 0.71 to 0.36) at 0–5 cm. The predictive accuracy for most soil properties declined with depth. Compared with previous soil maps, we achieved significantly more detailed and accurate predictions which could well represent soil variations across the territory and are a significant contribution to the GlobalSoilMap.net project. The relative importance of soil-forming factors in the predictions varied by specific soil property and depth, suggesting the complexity and non-stationarity of comprehensive multi-factor interactions in the process of soil development.
文摘′In this article, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved （G′/G）-expansion function method to calculate the exact solutions to the time- and space-fractional derivative foam drainage equation and the time- and space-fractional derivative nonlinear KdV equation. This method is efficient and powerful for solving wide classes of nonlinear evolution fractional order equations.
文摘In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's function is constructed.This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface.Then,the problem is divided into an upper and lower half space along the horizontal interface,regarded as a harmony model.In order to satisfy the integral continuity condition, the unknown anti-plane forces are applied to the interface.The integral equations with unknown forces can be established through the continuity condition,and after transformation,the algebraic equations are solved numerically.Finally,the distribution of the dynamic stress concentration factor(DSCF)around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.
文摘In this paper, antiplane response of an isosceles triangular hill to incident SH waves is studied based on the method of complex function and by using moving coordinate system. The standing wave function, which can satisfy the governing equation and boundary condition, is provided. Furthermore, numerical examples are presented; the influences of wave number and angle of the incident waves and the angle of the hill’s peak on ground motion are discussed.
基金This study was supported by the National Natural Science Foundation of China,No.81874464(to YHW)the Natural Science Foundation of Hunan Province of China,No.2019JJ50464(to HY)the Open Fund of the Domestic First-class Discipline Construction Project of Chinese Medicine of Hunan University of Chinese Medicine,No.2018ZYX46(to HY).
文摘In the peripheral nervous system,the activation of Sirtuin 1 can improve insulin resistance;however,the role played by Sirtuin 1 in the central nervous system remains unknown.In this study,rat models of diabetes mellitus were generated by a single injection of streptozotocin.At 8 weeks after streptozotocin injection,the Morris water maze test and western blot assays confirmed that the diabetic model rats had learning and memory deficits,insulin resistance,and Sirtuin 1 expression could be detected in the hippocampus.Insulin and the insulin receptor inhibitor S961 were intranasally administered to investigate the regulatory effects of insulin signaling on Sirtuin 1.The results showed that insulin administration improved the impaired cognitive function of diabetic model rats and increased the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1 in the hippocampus.Conversely,S961 administration resulted in more severe cognitive dysfunction and reduced the expression levels of phosphorylated insulin receptor,phosphorylated insulin receptor substrate 1,and Sirtuin 1.The Sirtuin 1 activator SRT2104 and the inhibitor Sirtinol were injected into the lateral ventricle,which revealed that the activation of Sirtuin 1 increased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor.Hippocampal dendritic length and spine density also increased in response to Sirtuin 1 activation.In contrast,Sirtinol decreased the expression levels of target of rapamycin complex 1,phosphorylated cAMP-response elementbinding protein,and brain-derived neurotrophic factor and damaged the dendritic structure.These findings suggest that the Sirtuin 1 signaling pathway plays an important role in the development of insulin resistance-related cognitive deficits in diabetic rats.This study was approved by the Animal Ethics Welfare Committee of the First Affiliated Hospital of Hunan University of Chinese Med
