Rare earth co-permeation of （NH4）3[CrMo6O24H6]·7H2O was reported and the conductivity of （NH4）3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry （XRF）, thermogravimetry-dif...Rare earth co-permeation of （NH4）3[CrMo6O24H6]·7H2O was reported and the conductivity of （NH4）3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry （XRF）, thermogravimetry-differential thermal analysis （TG-DTA）, X-ray diffraction （XRD） have been used to character （NH4）3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between （NH4）3[CrMo6O24H6]·7H2O and permeated sample. The structure of （NH4）3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.展开更多
In Saharan climates,greenhouses face extreme diurnal temperature fluctuations that generate thermal stress,reduce crop productivity,and hinder sustainable agricultural practices.Passive thermal storage using Phase Cha...In Saharan climates,greenhouses face extreme diurnal temperature fluctuations that generate thermal stress,reduce crop productivity,and hinder sustainable agricultural practices.Passive thermal storage using Phase Change Materials(PCM)is a promising solution to stabilize microclimatic conditions.This study aims to evaluate experimentally and numerically the effectiveness of PCM integration for moderating greenhouse temperature fluctuations under Saharan climatic conditions.Two identical greenhouse prototypes were constructed in Ghardaia,Algeria:a reference greenhouse and a PCM-integrated greenhouse using calcium chloride hexahydrate(CaCl_(2)⋅6H_(2)O).Thermal performance was assessed during a five-day experimental period(7–11May 2025)under severe ambient conditions.To complement this,a Nonlinear Auto-Regressive with eXogenous inputs(NARX)neural network model was developed and trained using a larger dataset(7–25 May 2025)to predict greenhouse thermal dynamics.The PCM greenhouse reduced peak daytime air temperature by an average of 8.14℃and decreased the diurnal temperature amplitude by 53.6%compared to the reference greenhouse.The NARX model achieved high predictive accuracy(R^(2)=0.990,RMSE=0.425℃,MAE=0.223℃,MBE=0.008℃),capturing both sensible and latent heat transfer mechanisms,including PCM melting and solidification.The combined experimental and predictive modeling results confirm the potential of PCM integration as an effective passive thermal regulation strategy for greenhouses in arid regions.This approach enhances microclimatic stability,improves energy efficiency,and supports the sustainability of protected agriculture under extreme climatic conditions.展开更多
Here we report that the presence of MgCO_(3) stimulates the extracellular polymeric substance (EPS) secretion of Microcystis Aeruginosa (M. Aeruginosa). This stimulation led to a significant reduction in the total con...Here we report that the presence of MgCO_(3) stimulates the extracellular polymeric substance (EPS) secretion of Microcystis Aeruginosa (M. Aeruginosa). This stimulation led to a significant reduction in the total concentration of NH_(4)^(+)‒N by more than 86%, and effective recovery of PO_(4)^(3-)‒P within three days from concentrated wastewater (WW), although the secreted EPS inhibited the conversion of MgCO_(3) to specific crystal forms (MgNH4PO4.6H2O or MgHPO4.7H2O). Moreover, with an increase in PO_(4)^(3-) concentration in WW, these crystals appeared, thus the removal of NH_(4)^(+)‒N and PO_(4)^(3-)‒P nutrients can be attributed to the combined effect of M. Aeruginosa and MgCO_(3). We used Surface-Enhanced Raman Spectroscopy (SERS) combined with X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS), and X-ray Photoelectron Spectroscopy (XPS) to investigate the mechanism for competitive interactions between M. Aeruginosa and MgCO_(3) in removing NH_(4)^(+)‒N and PO_(4)^(3-)‒P. We identified that the bound EPS accumulated amorphous Mg–P–O dense particles on M. Aeruginosa, while soluble EPS, containing –COOH groups of humic-like substances decreased the pH of the solution and coordinated with Mg^(2+) ions. Therefore, both secreted bound and soluble EPS play a vital role in hindering the transformation of Mg^(2+) ions or MgCO_(3) to MgNH4PO4.6H2O or MgHPO4.7H2O crystals within WW, and they enhanced M. Aeruginosa 's ability in absorbing nutrients of NH_(4)^(+)‒N and PO_(4)^(3-)‒P. This mechanism plays a crucial role in the efficient recovery of NH_(4)^(+)‒N and PO_(4)^(3-)‒P from concentrated wastewater sources such as aerobically or anaerobically digested effluent from various sources like agriculture, livestock, and domestic wastewaters.展开更多
In this work,porous biochar(MN-TRB_(750))was fabricated via direct pyrolysis of tea residue(TR)and Mg(NO_(3))_(2)·6H_(2)O(MN).The as-synthesized MN-TRB_(750) reached a specific surface area of 839.54 m^(2)·g...In this work,porous biochar(MN-TRB_(750))was fabricated via direct pyrolysis of tea residue(TR)and Mg(NO_(3))_(2)·6H_(2)O(MN).The as-synthesized MN-TRB_(750) reached a specific surface area of 839.54 m^(2)·g^(-1)and an average pore size of 3.75 nm with multi-level pore architecture.MN decreased TR's carbonization temperature and promoted the aromatics extent,pore structure for the frizzly flake-like biochar.Rhodamine B(RhB)was chosen as the adsorbate to explore the removal performance of organic dyes in this study.The results indicated that the maximum adsorption capacity of RhB on MN-TRB_(750) at 20℃ is up to 809.0 mg·g^(-1)with isotherms fitted well to Freundlich and Dubinin-Radushkevic models.The adsorption kinetics followed pseudo-second-order and Elovich models with an equilibrium adsorption capacity of 757.6 mg·g^(-1)as the initial concentration of RhB is 260 mg·L^(-1).High pore filling,hydrogen bond,π-πinteraction determined the adsorption of RhB onto MN-TRB850 through a multi-active center and exothermic chemical sorption process.展开更多
The challenge of high temperatures in deep mining remains harmful to the health of workers and their production efficiency The addition of phase change materials (PCMs) to filling slurry and the use of the cold storag...The challenge of high temperatures in deep mining remains harmful to the health of workers and their production efficiency The addition of phase change materials (PCMs) to filling slurry and the use of the cold storage function of these materials to reduce downhole temperatures is an effective approach to alleviate the aforementioned problem.Paraffin–CaCl_(2)·6H_(2)O composite PCM was prepared in the laboratory.The composition,phase change latent heat,thermal conductivity,and cemented tailing backfill (CTB) compressive strength of the new material were studied.The heat transfer characteristics and endothermic effect of the PCM were simulated using Fluent software.The results showed the following:(1) The new paraffin–CaCl_(2)·6H_(2)O composite PCM improved the thermal conductivity of native paraffin while avoiding the water solubility of CaCl_(2)·6H_(2)O.(2) The calculation formula of the thermal conductivity of CaCl_(2)·6H_(2)O combined with paraffin was deduced,and the reasons were explained in principle.(3) The“enthalpy–mass scale model”was applied to calculate the phase change latent heat of nonreactive composite PCMs.(4)The addition of the paraffin–CaCl_(2)·6H_(2)O composite PCM reduced the CTB strength but increased its heat absorption capacity.This research can give a theoretical foundation for the use of heat storage backfill in green mines.展开更多
基金the Key Science and Technology Foundation of Heilongjiang Province(Grant No.GB02A301) National Natural Science Foundation of China(Grant No.2037101)
文摘Rare earth co-permeation of （NH4）3[CrMo6O24H6]·7H2O was reported and the conductivity of （NH4）3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry （XRF）, thermogravimetry-differential thermal analysis （TG-DTA）, X-ray diffraction （XRD） have been used to character （NH4）3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between （NH4）3[CrMo6O24H6]·7H2O and permeated sample. The structure of （NH4）3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.
文摘In Saharan climates,greenhouses face extreme diurnal temperature fluctuations that generate thermal stress,reduce crop productivity,and hinder sustainable agricultural practices.Passive thermal storage using Phase Change Materials(PCM)is a promising solution to stabilize microclimatic conditions.This study aims to evaluate experimentally and numerically the effectiveness of PCM integration for moderating greenhouse temperature fluctuations under Saharan climatic conditions.Two identical greenhouse prototypes were constructed in Ghardaia,Algeria:a reference greenhouse and a PCM-integrated greenhouse using calcium chloride hexahydrate(CaCl_(2)⋅6H_(2)O).Thermal performance was assessed during a five-day experimental period(7–11May 2025)under severe ambient conditions.To complement this,a Nonlinear Auto-Regressive with eXogenous inputs(NARX)neural network model was developed and trained using a larger dataset(7–25 May 2025)to predict greenhouse thermal dynamics.The PCM greenhouse reduced peak daytime air temperature by an average of 8.14℃and decreased the diurnal temperature amplitude by 53.6%compared to the reference greenhouse.The NARX model achieved high predictive accuracy(R^(2)=0.990,RMSE=0.425℃,MAE=0.223℃,MBE=0.008℃),capturing both sensible and latent heat transfer mechanisms,including PCM melting and solidification.The combined experimental and predictive modeling results confirm the potential of PCM integration as an effective passive thermal regulation strategy for greenhouses in arid regions.This approach enhances microclimatic stability,improves energy efficiency,and supports the sustainability of protected agriculture under extreme climatic conditions.
基金supported by Cultivating Fund Project of Hubei Hongshan Laboratory(2022hspy002).
文摘Here we report that the presence of MgCO_(3) stimulates the extracellular polymeric substance (EPS) secretion of Microcystis Aeruginosa (M. Aeruginosa). This stimulation led to a significant reduction in the total concentration of NH_(4)^(+)‒N by more than 86%, and effective recovery of PO_(4)^(3-)‒P within three days from concentrated wastewater (WW), although the secreted EPS inhibited the conversion of MgCO_(3) to specific crystal forms (MgNH4PO4.6H2O or MgHPO4.7H2O). Moreover, with an increase in PO_(4)^(3-) concentration in WW, these crystals appeared, thus the removal of NH_(4)^(+)‒N and PO_(4)^(3-)‒P nutrients can be attributed to the combined effect of M. Aeruginosa and MgCO_(3). We used Surface-Enhanced Raman Spectroscopy (SERS) combined with X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS), and X-ray Photoelectron Spectroscopy (XPS) to investigate the mechanism for competitive interactions between M. Aeruginosa and MgCO_(3) in removing NH_(4)^(+)‒N and PO_(4)^(3-)‒P. We identified that the bound EPS accumulated amorphous Mg–P–O dense particles on M. Aeruginosa, while soluble EPS, containing –COOH groups of humic-like substances decreased the pH of the solution and coordinated with Mg^(2+) ions. Therefore, both secreted bound and soluble EPS play a vital role in hindering the transformation of Mg^(2+) ions or MgCO_(3) to MgNH4PO4.6H2O or MgHPO4.7H2O crystals within WW, and they enhanced M. Aeruginosa 's ability in absorbing nutrients of NH_(4)^(+)‒N and PO_(4)^(3-)‒P. This mechanism plays a crucial role in the efficient recovery of NH_(4)^(+)‒N and PO_(4)^(3-)‒P from concentrated wastewater sources such as aerobically or anaerobically digested effluent from various sources like agriculture, livestock, and domestic wastewaters.
基金Supported by the Innovation and Entrepreneurship Plan Project of Shaanxi Province and Shaanxi Xueqian Normal University for College Students(S202314390048,2023DC048)。
文摘In this work,porous biochar(MN-TRB_(750))was fabricated via direct pyrolysis of tea residue(TR)and Mg(NO_(3))_(2)·6H_(2)O(MN).The as-synthesized MN-TRB_(750) reached a specific surface area of 839.54 m^(2)·g^(-1)and an average pore size of 3.75 nm with multi-level pore architecture.MN decreased TR's carbonization temperature and promoted the aromatics extent,pore structure for the frizzly flake-like biochar.Rhodamine B(RhB)was chosen as the adsorbate to explore the removal performance of organic dyes in this study.The results indicated that the maximum adsorption capacity of RhB on MN-TRB_(750) at 20℃ is up to 809.0 mg·g^(-1)with isotherms fitted well to Freundlich and Dubinin-Radushkevic models.The adsorption kinetics followed pseudo-second-order and Elovich models with an equilibrium adsorption capacity of 757.6 mg·g^(-1)as the initial concentration of RhB is 260 mg·L^(-1).High pore filling,hydrogen bond,π-πinteraction determined the adsorption of RhB onto MN-TRB850 through a multi-active center and exothermic chemical sorption process.
基金financial support provided by the National Natural Science Foundation of China (No. 52174106)the Key Technology Research and Development Program (No. 2022YFC2905102)。
文摘The challenge of high temperatures in deep mining remains harmful to the health of workers and their production efficiency The addition of phase change materials (PCMs) to filling slurry and the use of the cold storage function of these materials to reduce downhole temperatures is an effective approach to alleviate the aforementioned problem.Paraffin–CaCl_(2)·6H_(2)O composite PCM was prepared in the laboratory.The composition,phase change latent heat,thermal conductivity,and cemented tailing backfill (CTB) compressive strength of the new material were studied.The heat transfer characteristics and endothermic effect of the PCM were simulated using Fluent software.The results showed the following:(1) The new paraffin–CaCl_(2)·6H_(2)O composite PCM improved the thermal conductivity of native paraffin while avoiding the water solubility of CaCl_(2)·6H_(2)O.(2) The calculation formula of the thermal conductivity of CaCl_(2)·6H_(2)O combined with paraffin was deduced,and the reasons were explained in principle.(3) The“enthalpy–mass scale model”was applied to calculate the phase change latent heat of nonreactive composite PCMs.(4)The addition of the paraffin–CaCl_(2)·6H_(2)O composite PCM reduced the CTB strength but increased its heat absorption capacity.This research can give a theoretical foundation for the use of heat storage backfill in green mines.
