The performance of a helical soil nailed structure is dependent on the installation torque required and the consequent pullout resistance developed.The present research work aims at proposing theoretical models to est...The performance of a helical soil nailed structure is dependent on the installation torque required and the consequent pullout resistance developed.The present research work aims at proposing theoretical models to estimate the required torque during installation of helical soil nails.Moreover,theoretical models are also developed to predict the pullout capacity of single and group of the helical nail for uniform and staggered arrangements.The proposed model predicts the pure-elastic and elastic-plastic pullout behavior of different helical nails.An equation for estimating the capacity-totorque Ratio(Kt)has also been developed for different nail shaft diameters.The results from the proposed models are validated with experimental results obtained from model testing of both single and group of helical nails.The predicted results are also compared for validation with the published literature.The results for installation torque and pullout load depict that the developed models predict values which are in accordance with the experimental results and are also found in good agreement with the published literature.Thus,the proposed models can effectively be used by the filed engineers for estimating the required installation torque and corresponding pullout capacities for single or double plate helical soil nails in cohesionless soil under surcharge pressure range of 0–50k Pa.展开更多
The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage de...The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEPCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing equations.The effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the Rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEPCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity fields.Furthermore,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented graphically.The results indicate that the time taken by the NEPCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf increases.Additionally,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.展开更多
The vulnerability of reinforced concrete(RC)building systems to progressive collapse has turned out to be a challenging trouble for professional structural engineers so as to prevent total failure on account of ...The vulnerability of reinforced concrete(RC)building systems to progressive collapse has turned out to be a challenging trouble for professional structural engineers so as to prevent total failure on account of nearby damage.The goal of this paper is to enhance the knowledge of such buildings’behavior underneath several scenarios of misplaced columns at different floor stages,and their capacity for progressive collapse.The homes had been analyzed following the guidelines for progressive collapse evaluation and design organized by means of the general services administration guidelines(GSA).The progressive collapse of a ten story structure subjected to a simplest gravity load is taken into consideration and the column has been eliminated at one place and the spread damage is evaluated.The progressive collapse study has been carried out by way of removing the column at a diagnosed crucial locations(at corner,middle and at interior)as in line with GSA guidelines.Static analysis is done using analysis program ETABS.For each case,the consequences were taken in terms of demand capacity ratio(DCR)at critical section,and as a result the structure has been assessed for it’s susceptible to progressive collapse.The availability of shear wall is made on the component wherein collapse occurred and DCR values are mentioned.After imparting the shear wall to the structure,the progressive collapse of the structure because of accidental load may be controlled in order that the GSA guidelines recommended DCR value would be within the range.展开更多
Achievement of lithium(Li)metal anode with thin thickness(e.g.,≤30µm)is highly desirable for rechargeable high energy density batteries.However,the fabrication and application of such thin Li metal foil electrod...Achievement of lithium(Li)metal anode with thin thickness(e.g.,≤30µm)is highly desirable for rechargeable high energy density batteries.However,the fabrication and application of such thin Li metal foil electrode remain challenging due to the poor mechanical processibility and inferior electrochemical performance of metallic Li.Here,mechanico-chemical synthesis of robust ultrathin Li/Li_(3)P(LLP)composite foils(~15µm)is demonstrated by employing repeated mechanical rolling/stacking operations using red P and metallic Li as raw materials.The in-situ formed Li+-conductive Li_(3)P nanoparticles in metallic Li matrix and their tight bonding strengthen the mechanical durability and enable the successful fabrication of free-standing ultrathin Li metal composite foil.Besides,it also reduces the electrochemical Li nucleation barrier and homogenizes Li plating/stripping behavior.When matching to high-voltage LiCoO_(2),the full cell with a low negative/positive(N/P)capacity ratio of~1.5 offers a high energy density of~522 W·h·kg^(-1) at 0.5 C based on the mass of cathode and anode.Taking into account its facile manufacturing,potentially low cost,and good electrochemical performance,we believe that such an ultrathin composite Li metal foil design with nanoparticle-dispersion-strengthened mechanism may boost the development of high energy density Li metal batteries.展开更多
We define and quantify for the first time over-credit at the firm level, which refers to the case in which the amount of bank credit that a firm obtains exceeds its expenditure on corporate investment for the year. Th...We define and quantify for the first time over-credit at the firm level, which refers to the case in which the amount of bank credit that a firm obtains exceeds its expenditure on corporate investment for the year. Then, we explore how over-credit affects corporate investment to determine whether credit expansion in China is consistent with the principle of finance serving the real economy. The results show that over-credit promotes firm investment, and this effect was enhanced by the housing boom. However, the effect of the property market reversed after 2012, owing to China's economic transition from a quantitative to a structural mismatch between supply and demand. Finally, we explore how over-credit affects the capacity utilization ratio and whether it has aggravated the overcapacity problem in China. The results show that over-credit reduces firms' capacity utilization ratio. This finding indicates that excessive credit expansion has exacerbated the overcapacity problem in China.展开更多
The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos (O,O-diethyl-O-(1-phenyl- 1,2,4-triazol-3-base) sulfur phosphate, TAP), which i...The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos (O,O-diethyl-O-(1-phenyl- 1,2,4-triazol-3-base) sulfur phosphate, TAP), which is an organophosphorus pesticide widespread applied for agriculture in China and moderately toxic to higher animal and fish. The tolerance, uptake, transformation and removal of TAP by twelve species of macrophytes were examined in a hydroponic system and a comprehensive score (CS) of five parameters (relative growth rate (RGR), biomass, root/shoot ratio, removal capacity (RC), and bio-concentration factor (BCF)) by factor analysis was employed to screen the potential macrophyte species for TAP phytoremediation. The results showed that Thalia dealbata, Cyperus alternifolius, Canna indica and Acorus calamus had higher RGR values, indicating these four species having stronger growth capacity under TAP stress. The higher RC loading in Iris pseudacorus and Cyperus rotundus were 42.11 and 24.63μg/(g fw.day), respectively. The highest values of BCF occurred in A. calamus (1.17), and TF occurred in Eichhornia crassipes (2.14). Biomass and root/shoot ratio of plant showed significant positive correlation with first-order kinetic constant of TAP removal in the hydroponic system, indicating that plant biomass and root system play important roles in remediation of TAP. Five plant species including C. alternifolius, A. calamus, T. dealbata, C. indica and Typha orientalis, which owned higher CS, would be potential species for TAP phytoremediation of contaminated water bodies.展开更多
文摘The performance of a helical soil nailed structure is dependent on the installation torque required and the consequent pullout resistance developed.The present research work aims at proposing theoretical models to estimate the required torque during installation of helical soil nails.Moreover,theoretical models are also developed to predict the pullout capacity of single and group of the helical nail for uniform and staggered arrangements.The proposed model predicts the pure-elastic and elastic-plastic pullout behavior of different helical nails.An equation for estimating the capacity-totorque Ratio(Kt)has also been developed for different nail shaft diameters.The results from the proposed models are validated with experimental results obtained from model testing of both single and group of helical nails.The predicted results are also compared for validation with the published literature.The results for installation torque and pullout load depict that the developed models predict values which are in accordance with the experimental results and are also found in good agreement with the published literature.Thus,the proposed models can effectively be used by the filed engineers for estimating the required installation torque and corresponding pullout capacities for single or double plate helical soil nails in cohesionless soil under surcharge pressure range of 0–50k Pa.
文摘The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEPCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing equations.The effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the Rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEPCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity fields.Furthermore,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented graphically.The results indicate that the time taken by the NEPCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf increases.Additionally,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.
文摘The vulnerability of reinforced concrete(RC)building systems to progressive collapse has turned out to be a challenging trouble for professional structural engineers so as to prevent total failure on account of nearby damage.The goal of this paper is to enhance the knowledge of such buildings’behavior underneath several scenarios of misplaced columns at different floor stages,and their capacity for progressive collapse.The homes had been analyzed following the guidelines for progressive collapse evaluation and design organized by means of the general services administration guidelines(GSA).The progressive collapse of a ten story structure subjected to a simplest gravity load is taken into consideration and the column has been eliminated at one place and the spread damage is evaluated.The progressive collapse study has been carried out by way of removing the column at a diagnosed crucial locations(at corner,middle and at interior)as in line with GSA guidelines.Static analysis is done using analysis program ETABS.For each case,the consequences were taken in terms of demand capacity ratio(DCR)at critical section,and as a result the structure has been assessed for it’s susceptible to progressive collapse.The availability of shear wall is made on the component wherein collapse occurred and DCR values are mentioned.After imparting the shear wall to the structure,the progressive collapse of the structure because of accidental load may be controlled in order that the GSA guidelines recommended DCR value would be within the range.
基金Y.S.acknowledges the financial support by National Natural Science Foundation of China(No.52272207)L.F.thanks the financial support by National Natural Science Foundation of China(No.22209031)+1 种基金Guizhou Provincial Basic Research Program(Natural Science)(No.QKHJC-ZK[2023]YB046)Natural Science Special Foundation of Guizhou University(No.X2022122 Special Post B).
文摘Achievement of lithium(Li)metal anode with thin thickness(e.g.,≤30µm)is highly desirable for rechargeable high energy density batteries.However,the fabrication and application of such thin Li metal foil electrode remain challenging due to the poor mechanical processibility and inferior electrochemical performance of metallic Li.Here,mechanico-chemical synthesis of robust ultrathin Li/Li_(3)P(LLP)composite foils(~15µm)is demonstrated by employing repeated mechanical rolling/stacking operations using red P and metallic Li as raw materials.The in-situ formed Li+-conductive Li_(3)P nanoparticles in metallic Li matrix and their tight bonding strengthen the mechanical durability and enable the successful fabrication of free-standing ultrathin Li metal composite foil.Besides,it also reduces the electrochemical Li nucleation barrier and homogenizes Li plating/stripping behavior.When matching to high-voltage LiCoO_(2),the full cell with a low negative/positive(N/P)capacity ratio of~1.5 offers a high energy density of~522 W·h·kg^(-1) at 0.5 C based on the mass of cathode and anode.Taking into account its facile manufacturing,potentially low cost,and good electrochemical performance,we believe that such an ultrathin composite Li metal foil design with nanoparticle-dispersion-strengthened mechanism may boost the development of high energy density Li metal batteries.
文摘We define and quantify for the first time over-credit at the firm level, which refers to the case in which the amount of bank credit that a firm obtains exceeds its expenditure on corporate investment for the year. Then, we explore how over-credit affects corporate investment to determine whether credit expansion in China is consistent with the principle of finance serving the real economy. The results show that over-credit promotes firm investment, and this effect was enhanced by the housing boom. However, the effect of the property market reversed after 2012, owing to China's economic transition from a quantitative to a structural mismatch between supply and demand. Finally, we explore how over-credit affects the capacity utilization ratio and whether it has aggravated the overcapacity problem in China. The results show that over-credit reduces firms' capacity utilization ratio. This finding indicates that excessive credit expansion has exacerbated the overcapacity problem in China.
基金supported by the National Natural Science Foundation of China (No. 20877093, 51278355)
文摘The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos (O,O-diethyl-O-(1-phenyl- 1,2,4-triazol-3-base) sulfur phosphate, TAP), which is an organophosphorus pesticide widespread applied for agriculture in China and moderately toxic to higher animal and fish. The tolerance, uptake, transformation and removal of TAP by twelve species of macrophytes were examined in a hydroponic system and a comprehensive score (CS) of five parameters (relative growth rate (RGR), biomass, root/shoot ratio, removal capacity (RC), and bio-concentration factor (BCF)) by factor analysis was employed to screen the potential macrophyte species for TAP phytoremediation. The results showed that Thalia dealbata, Cyperus alternifolius, Canna indica and Acorus calamus had higher RGR values, indicating these four species having stronger growth capacity under TAP stress. The higher RC loading in Iris pseudacorus and Cyperus rotundus were 42.11 and 24.63μg/(g fw.day), respectively. The highest values of BCF occurred in A. calamus (1.17), and TF occurred in Eichhornia crassipes (2.14). Biomass and root/shoot ratio of plant showed significant positive correlation with first-order kinetic constant of TAP removal in the hydroponic system, indicating that plant biomass and root system play important roles in remediation of TAP. Five plant species including C. alternifolius, A. calamus, T. dealbata, C. indica and Typha orientalis, which owned higher CS, would be potential species for TAP phytoremediation of contaminated water bodies.