目的:比较三氧矿化物凝聚体(MTA)和生物陶瓷(iRoot BP Plus)对乳牙深龋露髓后行活髓切断术的疗效影响。方法:纳入乳牙深龋露髓的患牙126颗,随机平均分为A组和B组(n=63)。A组用MTA覆盖活髓切断术牙髓组织断面,B组则使用iRoot BP Plus覆盖...目的:比较三氧矿化物凝聚体(MTA)和生物陶瓷(iRoot BP Plus)对乳牙深龋露髓后行活髓切断术的疗效影响。方法:纳入乳牙深龋露髓的患牙126颗,随机平均分为A组和B组(n=63)。A组用MTA覆盖活髓切断术牙髓组织断面,B组则使用iRoot BP Plus覆盖;比较2种材料的临床疗效,术后1、3、6、12、18月观察患牙的牙齿变色、牙髓、牙周膜及根分叉病变情况、根管内钙化情况以及根管的内外吸收情况,术后无任何不适症状视为治疗有效。结果:A组和B组成功率分别为96.8%和98.4%(P>0.05);牙齿变色率分别为100%和0%(P<0.05)。结论:用MTA和iRoot BP Plus作为乳牙活髓切断术盖髓剂,都能很好的保留乳牙根髓,但是iRoot BP Plus有更好的临床操作性并能避免乳牙出现牙体变色。展开更多
评价新型生物陶瓷(iRoot BP Plus)和三氧矿化物凝聚体(mineral trioxide aggregate,MTA)用于成熟恒牙活髓切断术的临床治疗效果。选择不可复性牙髓炎的成熟恒牙90颗,随机分为A组和B组。A组采用iRoot BP Plus盖髓行活髓切断术,B组采用MT...评价新型生物陶瓷(iRoot BP Plus)和三氧矿化物凝聚体(mineral trioxide aggregate,MTA)用于成熟恒牙活髓切断术的临床治疗效果。选择不可复性牙髓炎的成熟恒牙90颗,随机分为A组和B组。A组采用iRoot BP Plus盖髓行活髓切断术,B组采用MTA盖髓行活髓切断术,随访观察并比较术后1、3、6、12个月后两种材料的临床疗效。术后1个月,两组的成功率均为100%;术后3个月,A组的成功率为88.9%,B组的成功率为86.7%;术后6个月和12个月A组的成功率为88.9%,B组成功率为84.4%。两组的成功率差异无统计学意义(P>0.05)。与B组比较,A组的就诊次数更少,操作更简便。A组所有患牙均没有变色,而B组所有患牙均发生变色。iRoot BP Plus和MTA两种材料用于成熟恒牙活髓切断术的成功率均较高,且差异不显著,均适合做成熟恒牙的活髓保存治疗。但iRoot BP Plus不会导致牙齿变色,在美观方面显著优于MTA,临床操作简便。展开更多
This paper elaborated on the sustainability of the copper extraction process. In fact, an alternative copper extraction route from mixed sulphide ores, chalcopyrite and chalcocite using mesophilic biomass consortium a...This paper elaborated on the sustainability of the copper extraction process. In fact, an alternative copper extraction route from mixed sulphide ores, chalcopyrite and chalcocite using mesophilic biomass consortium at 33.3 °C and ferric leaching process were attempted. Bioleaching experiments were settled with a fraction size of-75+53 μm. Bacteria were used as the catalyst. A copper yield of 65.50% was obtained. On the other hand, in ferric leaching process, with a fraction size of-53+38 μm, when the temperature was increased to 70 °C, the copper leaching rate increased to 78.52%. Thus, comparatively, the mesophilic bioleaching process showed a more obvious advantage in copper extraction than leaching process with a high temperature. However, it has been resolved from the characterization performed using SEM-EDS, FTIR and XRD observations coupled with different thermodynamic approaches that, the indirect mechanism is the main leaching mechanism, with three transitory mechanisms(polysulphide, thiosulphate and elemental sulphur mechanisms) for the mixed chalcopyrite-chalcocite ore. Meanwhile, the speciation turns into Cu2 S-Cu S-Cu5 Fe S4-Cu2 S before turning into Cu SO4. While ferrous oxidation and the formation of ferric sulphate occur, and there is a formation of strong acid as bacteria digest sulphide minerals into copper sulphate at low temperature, which is why this copper production scenario requires a redox potential more than 550 m V at room temperature for high copper leaching rate.展开更多
Two CaCO3-based materials （limestone and clamshells） and steel slag were used as mineral admixtures in cement to produce ternary blends and their influences on hydration and portlandite formation were analyzed. Addi...Two CaCO3-based materials （limestone and clamshells） and steel slag were used as mineral admixtures in cement to produce ternary blends and their influences on hydration and portlandite formation were analyzed. Additionally, mechanical properties were determined. These properties were determined using X-ray diffraction and scanning electron microscopic/energy dispersive X-ray analytical techniques as well as applying methods specified by EN （European Standards） and ASTM （American Standards for Testing and Materials）. The portlandite （Ca（OH）E） content was considerably reduced from 36.9% of reference cement to between 13.79% and 15.5%. With the water demand and setting times of the cements containing up to 10%, admixtures did not change significantly. The mechanical tests results showed that ternary blends produced 2-day strengths higher than that specified by EN 197-1 and that blends containing up to 20% admixtures can be used to produce both Class 32.5N and 42.5N cements.展开更多
Humic substances （HS） substantially affect heavy metal （M） adsorption on mineral surfaces. However, quantitative descriptions of ternary systems involving M, HS and mineral surfaces remain unclear. This study exam...Humic substances （HS） substantially affect heavy metal （M） adsorption on mineral surfaces. However, quantitative descriptions of ternary systems involving M, HS and mineral surfaces remain unclear. This study examines adsorption in a model ternary system including Eu（III）, fulvic acid （FA） and silica, and describes the adsorption of Eu（III） and FA by combining a double-layer model （DLM） and the Stockholm humic model （SHM）. SHM explains the binding of H＋ and Eu^3＋ to EA and the DLM for FA and Eu（Ill） adsorption on silica. Experimental results showed that the presence of FA promotes Eu（III） adsorp- tion at acidic pH values, but decreases it at basic pH values, which indicates the formation of ternary surface complexes. Modeling calculations have shown that two ternary surface complexes are required to describe the experimental results in which Eu^3＋ acts as a bridge between the surface site and FA. The present study suggests that the discrete-site approach to HS is a promising method for interpreting the adsorption data for M, HS and mineral ternary systems.展开更多
Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous bloc...Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous block copolymers can be templates for producing three- dimensional TiO2 networks by combining the atomic layer deposition technique. Thickness adjustable TiO2 network is an excellent alternative scaffold material for efficient per- ovskite solar cells. Our best performing cells using such a 270 nm thick template have achieved a high efficiency of 12.5 % with pristine poly-3-hexylthiophene as a hole transport material. The high performance is attributed to the direct transport pathway and high absorption of scaf- folds, small leakage current and largely reduced recombi- nation rate at interfaces. The results show that TiO2 network architecture is a promising scaffold for meso- scopic perovskite solar cells.展开更多
It is widely stated that most organic contaminants could be completely mineralized by Advanced Oxidation Processes(AOPs). This statement means that the concentration of the organic contaminant at equilibrium(limiting ...It is widely stated that most organic contaminants could be completely mineralized by Advanced Oxidation Processes(AOPs). This statement means that the concentration of the organic contaminant at equilibrium(limiting concentration,LC)is low enough to be neglected.However,for environmental safety,especially drinking water safety,this statement needs to be verified from chemical engineering thermodynamic analysis.In this paper,trichloromethane(CHCl3)and dichloromethane(CH2Cl2) are selected as the model systems,and the equilibrium concentration(theoretical limiting concentration,TLC)for the mineralization of chlorinated methanes in aqueous solutions at the different initial concentrations of chlorinated methanes,pH values and·OH concentrations by AOPs are investigated by thermodynamic analysis.The results in this paper show that the TLC for the mineralization of CHCl3 and CH2Cl2 with·OH increases with increasing initial concentrations of CHCl3 and CH2Cl2,decreases with increasing concentration of·OH,and the TLC for the mineralization of CHCl3 decreases with increasing pH values except that the pH value changes from 3.0 to 3.5.For the mineralization of CH2Cl2 with·OH,at the concentrations of·OH obtained from the literature,there is no obvious change of the TLC with pH values,while as the concentrations of·OH increase by 10 and 100 times,the TLC decreases with the increasing pH values from 2.0 to 3.0 and from 3.5 to 4.5,and increases with the increasing pH values from 3.0 to 3.5 and from 4.5 to 5.0.The investigations in this paper imply that high concentration of·OH,a bit higher pH values(4.0–5.0)in acid environment and low initial concentrations of the organic contaminants are beneficial for the complete mineralization of chlorinated methanes by AOPs.展开更多
文摘目的:比较三氧矿化物凝聚体(MTA)和生物陶瓷(iRoot BP Plus)对乳牙深龋露髓后行活髓切断术的疗效影响。方法:纳入乳牙深龋露髓的患牙126颗,随机平均分为A组和B组(n=63)。A组用MTA覆盖活髓切断术牙髓组织断面,B组则使用iRoot BP Plus覆盖;比较2种材料的临床疗效,术后1、3、6、12、18月观察患牙的牙齿变色、牙髓、牙周膜及根分叉病变情况、根管内钙化情况以及根管的内外吸收情况,术后无任何不适症状视为治疗有效。结果:A组和B组成功率分别为96.8%和98.4%(P>0.05);牙齿变色率分别为100%和0%(P<0.05)。结论:用MTA和iRoot BP Plus作为乳牙活髓切断术盖髓剂,都能很好的保留乳牙根髓,但是iRoot BP Plus有更好的临床操作性并能避免乳牙出现牙体变色。
文摘评价新型生物陶瓷(iRoot BP Plus)和三氧矿化物凝聚体(mineral trioxide aggregate,MTA)用于成熟恒牙活髓切断术的临床治疗效果。选择不可复性牙髓炎的成熟恒牙90颗,随机分为A组和B组。A组采用iRoot BP Plus盖髓行活髓切断术,B组采用MTA盖髓行活髓切断术,随访观察并比较术后1、3、6、12个月后两种材料的临床疗效。术后1个月,两组的成功率均为100%;术后3个月,A组的成功率为88.9%,B组的成功率为86.7%;术后6个月和12个月A组的成功率为88.9%,B组成功率为84.4%。两组的成功率差异无统计学意义(P>0.05)。与B组比较,A组的就诊次数更少,操作更简便。A组所有患牙均没有变色,而B组所有患牙均发生变色。iRoot BP Plus和MTA两种材料用于成熟恒牙活髓切断术的成功率均较高,且差异不显著,均适合做成熟恒牙的活髓保存治疗。但iRoot BP Plus不会导致牙齿变色,在美观方面显著优于MTA,临床操作简便。
文摘This paper elaborated on the sustainability of the copper extraction process. In fact, an alternative copper extraction route from mixed sulphide ores, chalcopyrite and chalcocite using mesophilic biomass consortium at 33.3 °C and ferric leaching process were attempted. Bioleaching experiments were settled with a fraction size of-75+53 μm. Bacteria were used as the catalyst. A copper yield of 65.50% was obtained. On the other hand, in ferric leaching process, with a fraction size of-53+38 μm, when the temperature was increased to 70 °C, the copper leaching rate increased to 78.52%. Thus, comparatively, the mesophilic bioleaching process showed a more obvious advantage in copper extraction than leaching process with a high temperature. However, it has been resolved from the characterization performed using SEM-EDS, FTIR and XRD observations coupled with different thermodynamic approaches that, the indirect mechanism is the main leaching mechanism, with three transitory mechanisms(polysulphide, thiosulphate and elemental sulphur mechanisms) for the mixed chalcopyrite-chalcocite ore. Meanwhile, the speciation turns into Cu2 S-Cu S-Cu5 Fe S4-Cu2 S before turning into Cu SO4. While ferrous oxidation and the formation of ferric sulphate occur, and there is a formation of strong acid as bacteria digest sulphide minerals into copper sulphate at low temperature, which is why this copper production scenario requires a redox potential more than 550 m V at room temperature for high copper leaching rate.
文摘Two CaCO3-based materials （limestone and clamshells） and steel slag were used as mineral admixtures in cement to produce ternary blends and their influences on hydration and portlandite formation were analyzed. Additionally, mechanical properties were determined. These properties were determined using X-ray diffraction and scanning electron microscopic/energy dispersive X-ray analytical techniques as well as applying methods specified by EN （European Standards） and ASTM （American Standards for Testing and Materials）. The portlandite （Ca（OH）E） content was considerably reduced from 36.9% of reference cement to between 13.79% and 15.5%. With the water demand and setting times of the cements containing up to 10%, admixtures did not change significantly. The mechanical tests results showed that ternary blends produced 2-day strengths higher than that specified by EN 197-1 and that blends containing up to 20% admixtures can be used to produce both Class 32.5N and 42.5N cements.
基金supported by the National Natural Science Foundation of China(91226113,J1210001)
文摘Humic substances （HS） substantially affect heavy metal （M） adsorption on mineral surfaces. However, quantitative descriptions of ternary systems involving M, HS and mineral surfaces remain unclear. This study examines adsorption in a model ternary system including Eu（III）, fulvic acid （FA） and silica, and describes the adsorption of Eu（III） and FA by combining a double-layer model （DLM） and the Stockholm humic model （SHM）. SHM explains the binding of H＋ and Eu^3＋ to EA and the DLM for FA and Eu（Ill） adsorption on silica. Experimental results showed that the presence of FA promotes Eu（III） adsorp- tion at acidic pH values, but decreases it at basic pH values, which indicates the formation of ternary surface complexes. Modeling calculations have shown that two ternary surface complexes are required to describe the experimental results in which Eu^3＋ acts as a bridge between the surface site and FA. The present study suggests that the discrete-site approach to HS is a promising method for interpreting the adsorption data for M, HS and mineral ternary systems.
文摘Mesoscopic lead halide perovskite solar cells typically use TiO2 nanoparticle films as the scaffolds for electron-transport pathway and perovskite deposition. Here, we demonstrate that swelling-induced mesoporous block copolymers can be templates for producing three- dimensional TiO2 networks by combining the atomic layer deposition technique. Thickness adjustable TiO2 network is an excellent alternative scaffold material for efficient per- ovskite solar cells. Our best performing cells using such a 270 nm thick template have achieved a high efficiency of 12.5 % with pristine poly-3-hexylthiophene as a hole transport material. The high performance is attributed to the direct transport pathway and high absorption of scaf- folds, small leakage current and largely reduced recombi- nation rate at interfaces. The results show that TiO2 network architecture is a promising scaffold for meso- scopic perovskite solar cells.
基金supported by the Chinese National Key Technology Research and Development Program(2006AA03Z455)NSFC-RGC(20731160614)+2 种基金Program for Changjiang Scholars and Innovative Research Team in Univer-sity(IRT0732)National Basic Research Program of China(2009CB226103)the National Natural Science Foundation of China(20976080)
文摘It is widely stated that most organic contaminants could be completely mineralized by Advanced Oxidation Processes(AOPs). This statement means that the concentration of the organic contaminant at equilibrium(limiting concentration,LC)is low enough to be neglected.However,for environmental safety,especially drinking water safety,this statement needs to be verified from chemical engineering thermodynamic analysis.In this paper,trichloromethane(CHCl3)and dichloromethane(CH2Cl2) are selected as the model systems,and the equilibrium concentration(theoretical limiting concentration,TLC)for the mineralization of chlorinated methanes in aqueous solutions at the different initial concentrations of chlorinated methanes,pH values and·OH concentrations by AOPs are investigated by thermodynamic analysis.The results in this paper show that the TLC for the mineralization of CHCl3 and CH2Cl2 with·OH increases with increasing initial concentrations of CHCl3 and CH2Cl2,decreases with increasing concentration of·OH,and the TLC for the mineralization of CHCl3 decreases with increasing pH values except that the pH value changes from 3.0 to 3.5.For the mineralization of CH2Cl2 with·OH,at the concentrations of·OH obtained from the literature,there is no obvious change of the TLC with pH values,while as the concentrations of·OH increase by 10 and 100 times,the TLC decreases with the increasing pH values from 2.0 to 3.0 and from 3.5 to 4.5,and increases with the increasing pH values from 3.0 to 3.5 and from 4.5 to 5.0.The investigations in this paper imply that high concentration of·OH,a bit higher pH values(4.0–5.0)in acid environment and low initial concentrations of the organic contaminants are beneficial for the complete mineralization of chlorinated methanes by AOPs.
