We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to p...We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).展开更多
The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It i...The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It is found that larger-size QDs can be synthesized more easily when L-cysteine(Cys) or golutathione(GSH) is chosen as stabilizing agent and TGA is proper to prepare highly luminescent QDs because of the effect between Cd2+ and sulfhydryl group.Furthermore,the absorption wavelength,full width at half maximum(FWHM),stokes shift,photoluminescence(PL) quantum yield and PL stability of TGA-CdTe are strongly dependent on reaction time,in which the absorption wavelength changes against reaction time with an exponential function.The TGA-CdTe QDs prepared at 2 h possess more excellent luminescent properties.展开更多
The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how t...The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how these factors affect binding agents and soil aggregate stability along a climatic gradient remained unclear.We selected the Robinia pseudoacacia L.forests from semi-arid to semi-humid of the Loess Plateau,China to analyze the plant biomass,soil physical-chemical properties,SOC and GRSP distribution in different sized soil aggregates.We found that from semi-arid to semi-humid forests:(1)the proportion of macro-aggregates(>0.250 mm)significantly increased(P<0.05),whereas those of micro-aggregates(0.250–0.053 mm)and fine materials(<0.053 mm)decreased and soil aggregate stability was increased;(2)the contents of SOC and GRSP in macro-aggregates and micro-aggregates significantly increased,and those in fine materials decreased;(3)the contribution of SOC to soil aggregate stability was greater than those of total GRSP and easily extractable GRSP;(4)soil properties had greater influence on binding agents than plant biomass;and(5)soil aggregate stability was enhanced by increasing the contents of SOC and GRSP in macro-aggregates and soil property was the important part during this process.Climate change from semi-arid to semi-humid forests is important factor for soil structure formation because of its positive effect on soil aggregates.展开更多
One of the challenges faced by sewage sludge treatment and disposal is its higher water content,and how to efficient dewater those hazardous materials properly is welcome in practice. This study stabilized the sewage ...One of the challenges faced by sewage sludge treatment and disposal is its higher water content,and how to efficient dewater those hazardous materials properly is welcome in practice. This study stabilized the sewage sludge via the using of conventional curing agents and calcined aluminum salts,and the corresponding dewatering mechanisms and structural changes of the stabilized sludge were further comparable analyzed.Experimental results showed that wollastonite and kaolin exhibit a relative higher dewatering efficiency as compared to other conventional curing agents; however the releasing rate of heavy metals of Cu,Cr,Ni for kaolin solidification and Zn,Pb for wollastonite solidification is higher than the sludge samples solidified by other curing agents. For comparison,the sludge samples solidified by calcined aluminum salts (AS),calcium ash,Mg-based curing agent,tricalcium aluminate( C_3A) show a lower heavy metals leaching potential and unconfined compressive strength. In addition,the economic characteristics and local availability of AS,calcium ash,C_3A and CaO makes it have a broad prospect in extension and application. These findings are of great significance for stabilization and dewatering of sewage sludge.展开更多
Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability th...Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability through organic mulching in urban forest soils. Three treatments were applied in Jiufeng National Forest Park, Beijing: (1) no organic mulch (control);(2) wood chips alone (5 cm thickness);and, (3) wood chips + wood compost (This mulch was divided into two layers, the upper layer of wood chips (2.5 cm), the lower layer wood compost (2.5 cm)). Soil samples were collected from the surface 10- cm soil layer and fraction into four aggregates. Glomalin-related soil protein and soil organic carbon were measured in bulk soil and the four aggregates. The results show that wood chips + wood compost increased the proportion of large and small macroaggregates, mean weight diameter and geometric mean diameter. The total and easily extractable glomalin-related soil protein were higher in the wood chips + wood compost. However, soil organic carbon was lower in the wood chips alone application compared to the controls and wood chips + wood compost. Easily extractable / total glomalin-related soil protein and glomalin-related soil protein / soil organic carbon ratios of wood chips alone and wood chips + wood compost had increased trend compared to the controls but did not reach significant levels (p > 0.05). Mean weight diameter and geometric mean diameter correlated positively with total and easily extractable glomalin-related soil protein but were not positively correlated with soil organic carbon, the ratios of easily extractable and total glomalin-related soil protein, and the ratios of glomalin-related soil protein and soil organic carbon. Redundancy analysis revealed that total glomalin-related soil protein was the most important driver for soil aggregate stability, especially the total glomalin-related soil protein of small macroaggregates. The results suggest that wood chips + wood compost enhanced soil aggregate stability through the increase of glomalin-related soil protein. Wood chips alone cannot enhance soil aggregate stability in urban forests in the short term.展开更多
This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components ...This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components consisted of cement,slag and inorganic salt. The results showed that,increasing of curing ages could increase unconfined compressive strength and reduce moisture content for solidified sludge. For the test of two components,the biggest unconfined compressive strength of the solidified sludge achieved to 543. 72 kPa and the minimum moisture content achieved to 3. 56% of 21 d. The optimum proportion of the sludge curing agent of two components is sludge: cement: slag = 1 ∶ 0. 05 ∶ 0. 2 which selected by Design-expert. It could rapidly increasing the unconfined compressive strength of solidified sludge when added three components sludge curing agent( sludge: cement: slag: MgSO4= 1 ∶ 0. 05 ∶ 0. 2 ∶ 0. 03) on sludge curing. The results showed that,curing ages of 7 d,the unconfined compressive strength could achieve to 126. 74 kPa,which was more than 11 times comparison with the solidified sludge curing by two components curing agent. Two or three components sludge curing agent all could stabilize the heavy metals on solidified sludge and the leaching of heavy metals was below the government standard,while the stability of the heavy metals was superior for three components sludge curing agent.展开更多
Through embedding modified nano-silica particles on the surface of polystyrene using the method of Pickering emulsion polymerization,a kind of nano/micro oleophobic agent named OL-1 was developed.The effects of OL-1 o...Through embedding modified nano-silica particles on the surface of polystyrene using the method of Pickering emulsion polymerization,a kind of nano/micro oleophobic agent named OL-1 was developed.The effects of OL-1 on the rock surface properties and its performance in inhibiting the oil phase imbibition into the rock were explored.The performance and mechanisms of OL-1 in improving the wellbore stability of shale gas wells were evaluated and analyzed.OL-1 could absorb on the surface of the shale core to form a membrane with a micro-nano two-stage roughness,making the surface energy of the core decrease to 0.13 mN/m and the contact angle of the white oil on the core surface increase from 16.39°to 153.03°.Compared with the untreated capillary tube,when immersed into 3#white oil,the capillary tube treated by OL-1 had a reversal of capillary pressure from 273.76 Pa to-297.71 Pa,and the oil imbibition height inside the capillary tube decreased from 31 mm above the external liquid level to 33 mm below the external liquid level.The amount of oil invading into the rock core modified by OL-1 decreased by 64.29%compared with the untreated one.The shale core immersed into the oil-based drilling fluids with 1%OL-1 had a porosity reduction rate of only 4.5%.Compared with the core immersed in the drilling fluids without OL-1,the inherent force of the core treated by 1%OL-1 increased by 24.9%,demonstrating that OL-1 could effectively improve the rock mechanical stability by inhibiting oil phase imbibition.展开更多
All inorganic CsPbI_(3)perovskite solar cells(PSCs)have emerged as disruptive photovoltaic technology owing to their admirable photoelectric properties and the non-volatile active layer.However,the phase instability a...All inorganic CsPbI_(3)perovskite solar cells(PSCs)have emerged as disruptive photovoltaic technology owing to their admirable photoelectric properties and the non-volatile active layer.However,the phase instability against moisture severely limits the fabrication environment for the high-efficiency devices,breaking through the confinement region to achieve scalable manufacturing has been the primary issue for future commercialization.Here,we develop a curing-anti-solvent strategy for fabricating high-quality and stable black-phase CsPbI_(3)perovskite films in ambient air by introducing an inorganic polymer perhydropolysilazane(PHPS)into methyl acetate to form anti-template agent.The cross-linked PHPS reduces moisture erosions while the hydrolyzate silanol network(–Si(OH)_(4)^(–))controls the perovskite crystal growth by forming Lewis adducts with PbI_(2)during the fabrication.The polycondensation adduct of Si–O–Si/Si–O–Pb strongly binds to CsPbI_(3)grains as a shield layer to hamper phase transition.Using the inorganic CsPbI_(3)perovskite thin-film with PHPS-modified anti-solvent processing as the light absorber,the n–i–p planar solar cell achieved an efficiency of 19.17%under standard illumination test conditions.More importantly,the devices showed excellent moisture stability,retaining about 90%of the initial efficiency after 1000 h under 30%RH.展开更多
基金supported financially by the National Natural Science Foundation of China(41807102,U1710255-3 and 41907215)the Special Fund for Science and Technology Innovation Teams of Shanxi Province,China(202304051001042)the Distinguished and Excellent Young Scholar Cultivation Project of Shanxi Agricultural University,China(2022YQPYGC05)。
文摘We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes,as well as the formation mechanism of aggregates in reclaimed soil,to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province,China.In this study,soil samples of 0–20 cm depth were collected from four fertilization treatments of a longterm experiment started in 2008:no fertilizer (CK),inorganic fertilizer (NPK),chicken manure compost (M),and50%inorganic fertilizer plus 50%chicken manure compost (MNPK).The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed.The results showed that the formation of>2 mm aggregates,the aggregate mean weight diameter (MWD),and the proportion of>0.25 mm water-stable aggregates (WR_(0.25)) increased significantly after 6 and 11 years of reclamation.The concentration of organic cementing agents tended to increase with reclamation time,whereas free iron oxide (Fed) and free aluminium oxide(Ald) concentrations initially increased but then decreased.In general,the MNPK treatment signi?cantly increased the concentrations of organic cementing agents and CaCO_(3),and CaCO_(3) increased by 60.4%at 11 years after reclamation.Additionally,CaCO_(3) had the greatest effect on the stability of aggregates,promoting the formation of>0.25 mm aggregates and accounting for 54.4%of the variance in the proportion and stability of the aggregates.It was concluded that long-term reclamation is bene?cial for improving soil structure.The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO_(3).
基金Projects(10805069,10405034) supported by the National Natural Science Foundation of China
文摘The influence of stabilizing agents and reaction time on the luminescent properties of water-soluble CdTe quantum dots(QDs) was discussed.The thioglycolic acid(TGA)-CdTe ODs were characterized by TEM,XRD and FTIR.It is found that larger-size QDs can be synthesized more easily when L-cysteine(Cys) or golutathione(GSH) is chosen as stabilizing agent and TGA is proper to prepare highly luminescent QDs because of the effect between Cd2+ and sulfhydryl group.Furthermore,the absorption wavelength,full width at half maximum(FWHM),stokes shift,photoluminescence(PL) quantum yield and PL stability of TGA-CdTe are strongly dependent on reaction time,in which the absorption wavelength changes against reaction time with an exponential function.The TGA-CdTe QDs prepared at 2 h possess more excellent luminescent properties.
基金the National Key Research and Development Program of China(2017YFC0504601)the National Natural Science Foundation of China(41671513).
文摘The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how these factors affect binding agents and soil aggregate stability along a climatic gradient remained unclear.We selected the Robinia pseudoacacia L.forests from semi-arid to semi-humid of the Loess Plateau,China to analyze the plant biomass,soil physical-chemical properties,SOC and GRSP distribution in different sized soil aggregates.We found that from semi-arid to semi-humid forests:(1)the proportion of macro-aggregates(>0.250 mm)significantly increased(P<0.05),whereas those of micro-aggregates(0.250–0.053 mm)and fine materials(<0.053 mm)decreased and soil aggregate stability was increased;(2)the contents of SOC and GRSP in macro-aggregates and micro-aggregates significantly increased,and those in fine materials decreased;(3)the contribution of SOC to soil aggregate stability was greater than those of total GRSP and easily extractable GRSP;(4)soil properties had greater influence on binding agents than plant biomass;and(5)soil aggregate stability was enhanced by increasing the contents of SOC and GRSP in macro-aggregates and soil property was the important part during this process.Climate change from semi-arid to semi-humid forests is important factor for soil structure formation because of its positive effect on soil aggregates.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51408159)the China Postdoctoral Science Foundation of China(Grant No.2013T60375 and 2012M520744)
文摘One of the challenges faced by sewage sludge treatment and disposal is its higher water content,and how to efficient dewater those hazardous materials properly is welcome in practice. This study stabilized the sewage sludge via the using of conventional curing agents and calcined aluminum salts,and the corresponding dewatering mechanisms and structural changes of the stabilized sludge were further comparable analyzed.Experimental results showed that wollastonite and kaolin exhibit a relative higher dewatering efficiency as compared to other conventional curing agents; however the releasing rate of heavy metals of Cu,Cr,Ni for kaolin solidification and Zn,Pb for wollastonite solidification is higher than the sludge samples solidified by other curing agents. For comparison,the sludge samples solidified by calcined aluminum salts (AS),calcium ash,Mg-based curing agent,tricalcium aluminate( C_3A) show a lower heavy metals leaching potential and unconfined compressive strength. In addition,the economic characteristics and local availability of AS,calcium ash,C_3A and CaO makes it have a broad prospect in extension and application. These findings are of great significance for stabilization and dewatering of sewage sludge.
基金This project was supported fi nancially by the Natural Science Foundation of Beijing Municipality(Grant number 6202021).
文摘Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability through organic mulching in urban forest soils. Three treatments were applied in Jiufeng National Forest Park, Beijing: (1) no organic mulch (control);(2) wood chips alone (5 cm thickness);and, (3) wood chips + wood compost (This mulch was divided into two layers, the upper layer of wood chips (2.5 cm), the lower layer wood compost (2.5 cm)). Soil samples were collected from the surface 10- cm soil layer and fraction into four aggregates. Glomalin-related soil protein and soil organic carbon were measured in bulk soil and the four aggregates. The results show that wood chips + wood compost increased the proportion of large and small macroaggregates, mean weight diameter and geometric mean diameter. The total and easily extractable glomalin-related soil protein were higher in the wood chips + wood compost. However, soil organic carbon was lower in the wood chips alone application compared to the controls and wood chips + wood compost. Easily extractable / total glomalin-related soil protein and glomalin-related soil protein / soil organic carbon ratios of wood chips alone and wood chips + wood compost had increased trend compared to the controls but did not reach significant levels (p > 0.05). Mean weight diameter and geometric mean diameter correlated positively with total and easily extractable glomalin-related soil protein but were not positively correlated with soil organic carbon, the ratios of easily extractable and total glomalin-related soil protein, and the ratios of glomalin-related soil protein and soil organic carbon. Redundancy analysis revealed that total glomalin-related soil protein was the most important driver for soil aggregate stability, especially the total glomalin-related soil protein of small macroaggregates. The results suggest that wood chips + wood compost enhanced soil aggregate stability through the increase of glomalin-related soil protein. Wood chips alone cannot enhance soil aggregate stability in urban forests in the short term.
基金Sponsored by the Technology Research Projects of Harbin Science and Technology Bureau(Grant No.2010AA4CS024)the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.201192)+1 种基金the National Natural Science Key Foundation of China(Grant No.51206036)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(Grant No.2013DX04)
文摘This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components consisted of cement,slag and inorganic salt. The results showed that,increasing of curing ages could increase unconfined compressive strength and reduce moisture content for solidified sludge. For the test of two components,the biggest unconfined compressive strength of the solidified sludge achieved to 543. 72 kPa and the minimum moisture content achieved to 3. 56% of 21 d. The optimum proportion of the sludge curing agent of two components is sludge: cement: slag = 1 ∶ 0. 05 ∶ 0. 2 which selected by Design-expert. It could rapidly increasing the unconfined compressive strength of solidified sludge when added three components sludge curing agent( sludge: cement: slag: MgSO4= 1 ∶ 0. 05 ∶ 0. 2 ∶ 0. 03) on sludge curing. The results showed that,curing ages of 7 d,the unconfined compressive strength could achieve to 126. 74 kPa,which was more than 11 times comparison with the solidified sludge curing by two components curing agent. Two or three components sludge curing agent all could stabilize the heavy metals on solidified sludge and the leaching of heavy metals was below the government standard,while the stability of the heavy metals was superior for three components sludge curing agent.
基金Supported by National Natural Science Foundation of China (61079001, 61273006), National High Technology Research and Development Program of China (863 Program) (2011AA110301), and Specialized Research Fund for the Doctoral Program of Higher Education of China (20111103110017)
基金Supported by the CNPC Scientific Research and Technological Development Project(2021DJ3804)Scientific Research and Technological Development Project of PetroChina Company Limited(2020E-2803(JT))China CNPC Low Carbon Strategic Forward-Looking Major Science and Technology Project(2021DJ6601).
文摘Through embedding modified nano-silica particles on the surface of polystyrene using the method of Pickering emulsion polymerization,a kind of nano/micro oleophobic agent named OL-1 was developed.The effects of OL-1 on the rock surface properties and its performance in inhibiting the oil phase imbibition into the rock were explored.The performance and mechanisms of OL-1 in improving the wellbore stability of shale gas wells were evaluated and analyzed.OL-1 could absorb on the surface of the shale core to form a membrane with a micro-nano two-stage roughness,making the surface energy of the core decrease to 0.13 mN/m and the contact angle of the white oil on the core surface increase from 16.39°to 153.03°.Compared with the untreated capillary tube,when immersed into 3#white oil,the capillary tube treated by OL-1 had a reversal of capillary pressure from 273.76 Pa to-297.71 Pa,and the oil imbibition height inside the capillary tube decreased from 31 mm above the external liquid level to 33 mm below the external liquid level.The amount of oil invading into the rock core modified by OL-1 decreased by 64.29%compared with the untreated one.The shale core immersed into the oil-based drilling fluids with 1%OL-1 had a porosity reduction rate of only 4.5%.Compared with the core immersed in the drilling fluids without OL-1,the inherent force of the core treated by 1%OL-1 increased by 24.9%,demonstrating that OL-1 could effectively improve the rock mechanical stability by inhibiting oil phase imbibition.
基金support from the Natural Science Foundation of China(no.22005071)the Natural Science Special(Special Post)Research Foundation of Guizhou University(no.2020-13)The cultivation programs Research Foundation of Guizhou University(no.2019-64).
文摘All inorganic CsPbI_(3)perovskite solar cells(PSCs)have emerged as disruptive photovoltaic technology owing to their admirable photoelectric properties and the non-volatile active layer.However,the phase instability against moisture severely limits the fabrication environment for the high-efficiency devices,breaking through the confinement region to achieve scalable manufacturing has been the primary issue for future commercialization.Here,we develop a curing-anti-solvent strategy for fabricating high-quality and stable black-phase CsPbI_(3)perovskite films in ambient air by introducing an inorganic polymer perhydropolysilazane(PHPS)into methyl acetate to form anti-template agent.The cross-linked PHPS reduces moisture erosions while the hydrolyzate silanol network(–Si(OH)_(4)^(–))controls the perovskite crystal growth by forming Lewis adducts with PbI_(2)during the fabrication.The polycondensation adduct of Si–O–Si/Si–O–Pb strongly binds to CsPbI_(3)grains as a shield layer to hamper phase transition.Using the inorganic CsPbI_(3)perovskite thin-film with PHPS-modified anti-solvent processing as the light absorber,the n–i–p planar solar cell achieved an efficiency of 19.17%under standard illumination test conditions.More importantly,the devices showed excellent moisture stability,retaining about 90%of the initial efficiency after 1000 h under 30%RH.