Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by u...Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by utilizing CO_(2)mineralization curing technology.This study examined the dominant and interactive influences of the residual water/cement ratio,CO_(2)pressure,curing time,and SS content on the mechanical properties and CO_(2)uptake rate of CO_(2)mineralization curing SS-FA-Portland cement ternary paste specimens.Additionally,microstructural development was analyzed.The findings demonstrated that each factor significantly affected compressive strength and CO_(2)uptake rate,with factor interactions becoming more pronounced at higher SS dosages(>30%),lower residual water/cement ratios(0.1-0.15),and CO_(2)pressures of 0.1-0.3 MPa.Microscopic examinations revealed that mineralization primarily yielded CaCO_(3)and silica gel.The residual w/c ratio and SS content significantly influenced the CaCO_(3)content and crystallinity of the mineralization products.Post-mineralization curing,the percentage of pores larger than 50 nm significantly decreased,the proportion of harmless pores smaller than 20 nm increased,and pore structure improved.This study also found that using CO_(2)mineralization curing SS-FA-Portland cement solid waste concrete can significantly reduce the negative impact on the environment.展开更多
C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm...C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.展开更多
This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution conc...This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution concentrations of 3%,6%,9%,and 12%,the optimal dispersion effect was achieved with an ultrasonic dispersion time of 20 minutes.Specifically,at a 6%nano-TiO_(2)content,both the workability and mechanical performance of the cement paste were enhanced.Furthermore,while nano-TiO_(2)did not alter the types of hydration products present in the cement paste,it did increase the amount of C-S-H gels.This enhancement was attributed to a higher number of nucleation sites for hydration products,which promoted hydration and reduced the porosity of the cement paste.展开更多
The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hyd...The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hydroquinone（BBNBH）.The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA,leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction.This modified electrode exhibits well-separated oxidation peaks for AA and uric acid（UA）.The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.展开更多
CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the ...CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the CPB with CEV added was prepared,and the specific heat capacity,thermal conductivity,and uniaxial compressive strength(UCS)of CPB with different cement-tailing ratios and CEV addition ratios were tested,the influence of the above variables on the thermal and mechanical properties of CPB was analyzed.The results show that the maximum encapsulation capacity of expanded vermiculite for CaCl_(2)·6H_(2)O is about 60%,and the melting and solidification enthalpies of CEV can reach 98.87 J/g and 97.56 J/g,respectively.For the CPB without CEV,the specific heat capacity,thermal conductivity,and UCS decrease with the decrease of cement-tailing ratio.For the CPB with CEV added,with the increase of CEV addition ratio,the specific heat capacity increases significantly,and the sensible heat storage capacity and latent heat storage capacity can be increased by at least 10.74%and 218.97%respectively after adding 12%CEV.However,the addition of CEV leads to the increase of pores,and the thermal conductivity and UCS both decrease with the increase of CEV addition.When cement-tailing ratio is 1:8 and 6%,9%,and 12%of CEV are added,the 28-days UCS of CPB is less than 1 MPa.Considering the heat storage capacity and cost price of backfill,the recommended proportion scheme of CPB material presents cement-tailing ratio of 1:6 and 12%CEV,and the most recommended heat storage/release temperature cycle range of CPB with added CEV is from 20 to 40℃.This work can provide theoretical basis for the utilization of heat storage backfill in green mines.展开更多
The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which...The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al 2 O 3 substrates,and then sintering in a belt furnace.X-ray diffraction(XRD) and electron scanning microscopy(SEM) have been used to characterize the conductive particles.The resistors exhibit good refiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80Ω/□ to 600Ω/□.The resistors prepared are qualified for common use.展开更多
The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry w...The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.展开更多
目的:基于乙二醛酶-1(GLO-1)/晚期糖基化终末产物(AGE)/晚期糖基化终末产物受体(RAGE)通路探讨糖痹康干膏防治2型糖尿病周围神经病变(DPN)的作用机制。方法:56只SD大鼠随机选取8只为正常组,其余48只大鼠予高脂饲料喂养联合腹腔注射链脲...目的:基于乙二醛酶-1(GLO-1)/晚期糖基化终末产物(AGE)/晚期糖基化终末产物受体(RAGE)通路探讨糖痹康干膏防治2型糖尿病周围神经病变(DPN)的作用机制。方法:56只SD大鼠随机选取8只为正常组,其余48只大鼠予高脂饲料喂养联合腹腔注射链脲佐菌素(STZ)诱导2型糖尿病(T2DM)模型,按血糖将大鼠随机分为模型组、唐林组(13.5 mg·kg^(-1))、二甲双胍组(135 mg·kg^(-1))和糖痹康干膏低、中、高剂量组(3、6、12 g·kg^(-1))。干预第4周模型组机械痛痛阈下降则DPN造模成功。每4周测定大鼠的空腹血糖、体质量、机械痛痛阈。干预16周,苏木素-伊红(HE)染色法观察坐骨神经病理形态,免疫组化法检测坐骨神经RAGE、AGE、蛋白激酶C(PKC)、胶原蛋白(COL)表达,实时荧光定量聚合酶链式反应(Real-time PCR)检测坐骨神经RAGE、PKC、Toll样受体(TLR)、COL、GLO-1 m RNA表达。酶联免疫吸附测定法(ELISA)检测大鼠血清天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、肌酐(CREA)、尿素(UREA)、白细胞介素-6(IL-6)、肿瘤坏死因子(TNF)-α含量。结果:与正常组比较,模型组空腹血糖升高(P<0.01),体质量及机械痛痛阈降低(P<0.01),血清AST、ALT、CREA、UREA、IL-6、TNF-α升高(P<0.01),坐骨神经RAGE、AGE、PKC表达升高(P<0.01),COL表达降低(P<0.01),TLR、RAGE、PKC m RNA表达升高(P<0.01),COL、GLO-1 m RNA表达降低(P<0.01),坐骨神经形态不规则、轴索形态改变、髓鞘变性。与模型组比较,糖痹康干膏高剂量组各时间,中剂量组给药第4、16周空腹血糖降低(P<0.05,P<0.01);糖痹康干膏各剂量组体质量无明显变化;糖痹康干膏各剂量组在给药后不同时间出现痛阈升高(P<0.05,P<0.01);各剂量组血清IL-6、TNF-α含量下降(P<0.05,P<0.01);糖痹康干膏各剂量组坐骨神经中RAGE、AGE、PKC表达降低(P<0.01),COL表达升高(P<0.01),TLR、RAGE、PKC m RNA表达降低(P<0.01),GLO-1 m RNA表达升高(P<0.05,P<0.01),低、高剂量组COL m RNA表达升高(P<0.01),糖痹康干膏各剂量组病理表现均较模型组病变程度轻。结论:糖痹康干膏具有明显改善DPN作用,其机制可能与调控GLO-1/AGE/RAGE通路作用有关。展开更多
基金Project(52479115)supported by the National Natural Science Foundation of ChinaProject(2024SF-YBXM-615)supported by the Key Research and Development Program of Shaanxi Province,China+1 种基金Project(2022943)supported by the Youth Innovation Team of Shaanxi Universities,ChinaProject(300102283721)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Using solid waste as a substitute for conventional cement has become an important way to reduce carbon emissions.This paper attempted to utilize steel slag(SS)and fly ash(FA)as supplementary cementitious material by utilizing CO_(2)mineralization curing technology.This study examined the dominant and interactive influences of the residual water/cement ratio,CO_(2)pressure,curing time,and SS content on the mechanical properties and CO_(2)uptake rate of CO_(2)mineralization curing SS-FA-Portland cement ternary paste specimens.Additionally,microstructural development was analyzed.The findings demonstrated that each factor significantly affected compressive strength and CO_(2)uptake rate,with factor interactions becoming more pronounced at higher SS dosages(>30%),lower residual water/cement ratios(0.1-0.15),and CO_(2)pressures of 0.1-0.3 MPa.Microscopic examinations revealed that mineralization primarily yielded CaCO_(3)and silica gel.The residual w/c ratio and SS content significantly influenced the CaCO_(3)content and crystallinity of the mineralization products.Post-mineralization curing,the percentage of pores larger than 50 nm significantly decreased,the proportion of harmless pores smaller than 20 nm increased,and pore structure improved.This study also found that using CO_(2)mineralization curing SS-FA-Portland cement solid waste concrete can significantly reduce the negative impact on the environment.
基金Funded by the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(No.IRT1146)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘C3S pastes containing 0%,5%,10%,and 15%nano-SiO2 mixed with de-ionized water and alkali solutions were prepared.When C3S was completely hydrated,the pastes were ground into powders with a particle size less than 80μm.Adsorption and desorption characteristics of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water immersed in alkali solutions and those in C3S-nano SiO2 pastes mixed with alkali solutions,were investigated.Meawhile,the adsorption mechanisms of alkali ions were discussed.Results showed that the contents of alkali ions adsorbed by C3S-nano SiO2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO2 and/or the initial alkali concentrations.In C3S-nano SiO2 pastes mixed with de-ionized water,each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration.No obvious difference between the adsorption capacity of a given paste for K~＋and Na~＋was observed.Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste,and charge compensation of C-S-H gel,mainly by electrostatic interactions.In C3S-nano SiO2 pastes mixed with alkali solutions,alkali ions may enter the structure of C-S-H gel to replace a part of Ca^2＋in the interlayer.This assumption is supported by the structural characterization of C-S-H gel using ^（29）Si MAS NMR.
基金Funded by National Natural Science Foundation of China(No.52108188)State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2024-15)+3 种基金State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University(No.SKLBT-2301)Opening Project of State Key Laboratory of Green Building Materials(No.2022GBM10)Open Research Fund of Key Laboratory of Engineering Materials of Ministry of Water Resources,China Institute of Water Resources and Hydropower Research(No.EMF202407)General Project of Science and Technology Plan of Beijing Municipal Commission of Education(No.KM202110005018)。
文摘This article investigated the factors and mechanisms that affected the workability and mechanical properties of cement paste incorporating nano-TiO_(2).The findings indicated that,for nano-TiO_(2)aqueous solution concentrations of 3%,6%,9%,and 12%,the optimal dispersion effect was achieved with an ultrasonic dispersion time of 20 minutes.Specifically,at a 6%nano-TiO_(2)content,both the workability and mechanical performance of the cement paste were enhanced.Furthermore,while nano-TiO_(2)did not alter the types of hydration products present in the cement paste,it did increase the amount of C-S-H gels.This enhancement was attributed to a higher number of nucleation sites for hydration products,which promoted hydration and reduced the porosity of the cement paste.
文摘The electrochemical behavior of vitamin C（ascorbic acid or AA） is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2＇-（1,2 butanediylbis（nitriloethylidyne））-bis-hydroquinone（BBNBH）.The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA,leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction.This modified electrode exhibits well-separated oxidation peaks for AA and uric acid（UA）.The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.
基金supported by the National Natural Science Foundation of China(Nos.51974225,51874229,51674188,51904224,51904225)the Shaanxi Innovative Talents Cultivate Program-New-star Plan of Science and Technology,China(No.2018KJXX-083)+2 种基金the Natural Science Basic Research Plan of Shaanxi Province of China(Nos.2018JM 5161,2018JQ5183,2019JM-074)the Scientific Research Program funded by the Shaanxi Provincial Education Department,China(No.19JK0543)the Outstanding Youth Science Fund of Xi’an University of Science and Technology,China(No.2018YQ2-01)。
文摘CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the CPB with CEV added was prepared,and the specific heat capacity,thermal conductivity,and uniaxial compressive strength(UCS)of CPB with different cement-tailing ratios and CEV addition ratios were tested,the influence of the above variables on the thermal and mechanical properties of CPB was analyzed.The results show that the maximum encapsulation capacity of expanded vermiculite for CaCl_(2)·6H_(2)O is about 60%,and the melting and solidification enthalpies of CEV can reach 98.87 J/g and 97.56 J/g,respectively.For the CPB without CEV,the specific heat capacity,thermal conductivity,and UCS decrease with the decrease of cement-tailing ratio.For the CPB with CEV added,with the increase of CEV addition ratio,the specific heat capacity increases significantly,and the sensible heat storage capacity and latent heat storage capacity can be increased by at least 10.74%and 218.97%respectively after adding 12%CEV.However,the addition of CEV leads to the increase of pores,and the thermal conductivity and UCS both decrease with the increase of CEV addition.When cement-tailing ratio is 1:8 and 6%,9%,and 12%of CEV are added,the 28-days UCS of CPB is less than 1 MPa.Considering the heat storage capacity and cost price of backfill,the recommended proportion scheme of CPB material presents cement-tailing ratio of 1:6 and 12%CEV,and the most recommended heat storage/release temperature cycle range of CPB with added CEV is from 20 to 40℃.This work can provide theoretical basis for the utilization of heat storage backfill in green mines.
文摘The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al 2 O 3 substrates,and then sintering in a belt furnace.X-ray diffraction(XRD) and electron scanning microscopy(SEM) have been used to characterize the conductive particles.The resistors exhibit good refiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80Ω/□ to 600Ω/□.The resistors prepared are qualified for common use.
文摘The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.
文摘目的:基于乙二醛酶-1(GLO-1)/晚期糖基化终末产物(AGE)/晚期糖基化终末产物受体(RAGE)通路探讨糖痹康干膏防治2型糖尿病周围神经病变(DPN)的作用机制。方法:56只SD大鼠随机选取8只为正常组,其余48只大鼠予高脂饲料喂养联合腹腔注射链脲佐菌素(STZ)诱导2型糖尿病(T2DM)模型,按血糖将大鼠随机分为模型组、唐林组(13.5 mg·kg^(-1))、二甲双胍组(135 mg·kg^(-1))和糖痹康干膏低、中、高剂量组(3、6、12 g·kg^(-1))。干预第4周模型组机械痛痛阈下降则DPN造模成功。每4周测定大鼠的空腹血糖、体质量、机械痛痛阈。干预16周,苏木素-伊红(HE)染色法观察坐骨神经病理形态,免疫组化法检测坐骨神经RAGE、AGE、蛋白激酶C(PKC)、胶原蛋白(COL)表达,实时荧光定量聚合酶链式反应(Real-time PCR)检测坐骨神经RAGE、PKC、Toll样受体(TLR)、COL、GLO-1 m RNA表达。酶联免疫吸附测定法(ELISA)检测大鼠血清天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、肌酐(CREA)、尿素(UREA)、白细胞介素-6(IL-6)、肿瘤坏死因子(TNF)-α含量。结果:与正常组比较,模型组空腹血糖升高(P<0.01),体质量及机械痛痛阈降低(P<0.01),血清AST、ALT、CREA、UREA、IL-6、TNF-α升高(P<0.01),坐骨神经RAGE、AGE、PKC表达升高(P<0.01),COL表达降低(P<0.01),TLR、RAGE、PKC m RNA表达升高(P<0.01),COL、GLO-1 m RNA表达降低(P<0.01),坐骨神经形态不规则、轴索形态改变、髓鞘变性。与模型组比较,糖痹康干膏高剂量组各时间,中剂量组给药第4、16周空腹血糖降低(P<0.05,P<0.01);糖痹康干膏各剂量组体质量无明显变化;糖痹康干膏各剂量组在给药后不同时间出现痛阈升高(P<0.05,P<0.01);各剂量组血清IL-6、TNF-α含量下降(P<0.05,P<0.01);糖痹康干膏各剂量组坐骨神经中RAGE、AGE、PKC表达降低(P<0.01),COL表达升高(P<0.01),TLR、RAGE、PKC m RNA表达降低(P<0.01),GLO-1 m RNA表达升高(P<0.05,P<0.01),低、高剂量组COL m RNA表达升高(P<0.01),糖痹康干膏各剂量组病理表现均较模型组病变程度轻。结论:糖痹康干膏具有明显改善DPN作用,其机制可能与调控GLO-1/AGE/RAGE通路作用有关。
