目的:探究观察3M Single Bond Universal粘接系统对前牙E-max铸瓷贴面修复的远期疗效。方法:选择2017年5月-2019年5月笔者医院收治的需前牙E-max铸瓷贴面修复患者63例(患牙113颗)为研究对象,均行经典贴面修复,根据粘接系统的不同将患者...目的:探究观察3M Single Bond Universal粘接系统对前牙E-max铸瓷贴面修复的远期疗效。方法:选择2017年5月-2019年5月笔者医院收治的需前牙E-max铸瓷贴面修复患者63例(患牙113颗)为研究对象,均行经典贴面修复,根据粘接系统的不同将患者分为观察组(患者21例,患牙40颗,采用3M Single Bond Universal粘接系统)、对照1组(患者21例,患牙36颗,采用VariolinkⅡ粘接系统)、对照2组(患者21例,患牙37颗,采用BISCO CHOICE 2粘接系统)。治疗后三组均于1周、3个月、12个月时进行随访,观察三组治疗后1周、3个月、12个月内贴面修复效果、贴面修复失败率及不良反应发生率。结果:术后1周,三组患者均无失败案例;对照1组存在2颗修复体保存完整度为Ⅰ级的患牙,对照2组存在3颗修复体保存完整度为I级的患牙,观察组未存在该类患者;术后12个月,观察组存在1颗修复体保存完整度Ⅱ级患牙,对照1组存在1颗保存完整度I级患牙,3颗修复体保存完整度Ⅱ级患牙,对照2组存在2颗保存完整度I级患牙,3颗修复体保存完整度Ⅱ级患牙。三组患者治疗效果比较,差异无统计学意义(P>0.05);术后1周、3个月、12个月三组贴面修复失败率比较,差异无统计学意义(P>0.05);随访期间内,三组患者不良反应情况比较差异均无统计学意义(P>0.05)。结论:对于前牙E-max铸瓷贴面修复患者,选取合适的适应证,并做好备牙步骤,3M Single Bond Universal与经典VariolinkⅡ粘接系统及BISCO CHOICE 2粘接系统治疗效果并无显著差异,值得在临床推广使用。展开更多
In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.H...In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.HT piezoelectric ceramics(1x)BiScO_(3-x)PbTiO_(3)(BS-PT)are considered as one of the most competitive piezoelectric actuation materials used in the harsh environment because of its high Curie temperature(T_(C)=450℃)as well as high piezoelectric coefficient(d_(33)=460 pC/N)in the MPB composition.This paper summarized the recent progress in HT piezoelectric ceramics and actuators based on BS-PT solid solutions.The properties of BS-PT piezoelectric ceramics and actuators,including driving mechanisms,actuation performances and their applications in HT environment were also discussed.展开更多
BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high t...BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures.In this work,a ternary perovskite system of(1-x-y)BiScO3-yPbTiO3-xBi(Mn_(2/3)Sb_(1/3))O_(3)(BS-yPT-xBMS)with x=0.005,y=0.630-0.645 and x=0.015,y=0.625-0.640 was prepared by the traditional solid-state reaction method.The phase structure,microstructure,dielectric/piezoelectric/ferroelectric properties were studied.Among BS-yPT-xBMS ceramic series,the BS-0.630PT-0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor(tanδ=1.20%)and increased mechanical quality factor(Qm=84),and maintains a high Curie temperature(TC=410°C)and excellent piezoelectric properties(d_(33)=330 pC/N)simultaneously.Of particular importance,at elevated temperature of 200°C,the value of tanδis only increased to 1.59%.All these properties indicate that the BS-0.630PT-0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.展开更多
PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying pie...PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).展开更多
Solid solutions on the base of composition from morphotropic phase boundary(1-x)BiScO_(3)–xPbTiO_(3) with x=0.64,0.645,0.65 were prepared from nitrates solutions.Variations in phase content,structure parameters,micro...Solid solutions on the base of composition from morphotropic phase boundary(1-x)BiScO_(3)–xPbTiO_(3) with x=0.64,0.645,0.65 were prepared from nitrates solutions.Variations in phase content,structure parameters,microstructure,dielectric and piezoelectric properties of dense ceramic samples were studied.The first-order phase transitions were observed at temperatures near 700 K.The influence of the processing conditions on the morphology,temperature of phase transitions,and dielectric parameters was observed.In some ceramics effect of dielectric relaxation was observed at high temperatures.This effect was explained by the contribution from ionic transport due to the oxygen vacancies creation during high temperature sintering.展开更多
文摘目的:探究观察3M Single Bond Universal粘接系统对前牙E-max铸瓷贴面修复的远期疗效。方法:选择2017年5月-2019年5月笔者医院收治的需前牙E-max铸瓷贴面修复患者63例(患牙113颗)为研究对象,均行经典贴面修复,根据粘接系统的不同将患者分为观察组(患者21例,患牙40颗,采用3M Single Bond Universal粘接系统)、对照1组(患者21例,患牙36颗,采用VariolinkⅡ粘接系统)、对照2组(患者21例,患牙37颗,采用BISCO CHOICE 2粘接系统)。治疗后三组均于1周、3个月、12个月时进行随访,观察三组治疗后1周、3个月、12个月内贴面修复效果、贴面修复失败率及不良反应发生率。结果:术后1周,三组患者均无失败案例;对照1组存在2颗修复体保存完整度为Ⅰ级的患牙,对照2组存在3颗修复体保存完整度为I级的患牙,观察组未存在该类患者;术后12个月,观察组存在1颗修复体保存完整度Ⅱ级患牙,对照1组存在1颗保存完整度I级患牙,3颗修复体保存完整度Ⅱ级患牙,对照2组存在2颗保存完整度I级患牙,3颗修复体保存完整度Ⅱ级患牙。三组患者治疗效果比较,差异无统计学意义(P>0.05);术后1周、3个月、12个月三组贴面修复失败率比较,差异无统计学意义(P>0.05);随访期间内,三组患者不良反应情况比较差异均无统计学意义(P>0.05)。结论:对于前牙E-max铸瓷贴面修复患者,选取合适的适应证,并做好备牙步骤,3M Single Bond Universal与经典VariolinkⅡ粘接系统及BISCO CHOICE 2粘接系统治疗效果并无显著差异,值得在临床推广使用。
基金supported by the National Natural Science Foundation of China(Grant Nos.51132001,51072003,11090331,51302163)the Innovational Foundation of Shanghai University(Grant No.K.10-0110-13-009).
文摘In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.HT piezoelectric ceramics(1x)BiScO_(3-x)PbTiO_(3)(BS-PT)are considered as one of the most competitive piezoelectric actuation materials used in the harsh environment because of its high Curie temperature(T_(C)=450℃)as well as high piezoelectric coefficient(d_(33)=460 pC/N)in the MPB composition.This paper summarized the recent progress in HT piezoelectric ceramics and actuators based on BS-PT solid solutions.The properties of BS-PT piezoelectric ceramics and actuators,including driving mechanisms,actuation performances and their applications in HT environment were also discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.51972144,U1806221 and U2006218)the Taishan Scholars Program,the Case-by-Case Project for Top Outstanding Talents of Jinan,the Shandong Provincial Natural Science Foundation(Grant No.ZR2020KA003)+2 种基金the Primary Research&Development Plan of Shandong Province(Grant No.2019JZZY010313)the Project of“20 Items of University”of Jinan(Grant Nos.T202009 and T201907)the Introduction Program of Senior Foreign Experts(G2021024003L).
文摘BiScO_(3)-PbTiO_(3)binary ceramics own both high Curie temperature and prominent piezoelectric properties,while the high dielectric loss needs to be reduced substantially for practical application especially at high temperatures.In this work,a ternary perovskite system of(1-x-y)BiScO3-yPbTiO3-xBi(Mn_(2/3)Sb_(1/3))O_(3)(BS-yPT-xBMS)with x=0.005,y=0.630-0.645 and x=0.015,y=0.625-0.640 was prepared by the traditional solid-state reaction method.The phase structure,microstructure,dielectric/piezoelectric/ferroelectric properties were studied.Among BS-yPT-xBMS ceramic series,the BS-0.630PT-0.015BMS at morphotropic phase boundary possesses the reduced dielectric loss factor(tanδ=1.20%)and increased mechanical quality factor(Qm=84),and maintains a high Curie temperature(TC=410°C)and excellent piezoelectric properties(d_(33)=330 pC/N)simultaneously.Of particular importance,at elevated temperature of 200°C,the value of tanδis only increased to 1.59%.All these properties indicate that the BS-0.630PT-0.015BMS ceramic has great potential for application in high-temperature piezoelectric devices.
基金supported by the National Natural Science Foundation of China(21825102,22075014 and 12004032)the Fundamental Research Funds for the Central Universities,China(06500162)+2 种基金the National Postdoctoral Program for Innovative Talents(BX20200044)German Research Society(DFG)(HI 1867/1-2)supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357.
文摘PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).
基金supported by the Russian Foundation for Basic Research,Grant No.12-03-00388.
文摘Solid solutions on the base of composition from morphotropic phase boundary(1-x)BiScO_(3)–xPbTiO_(3) with x=0.64,0.645,0.65 were prepared from nitrates solutions.Variations in phase content,structure parameters,microstructure,dielectric and piezoelectric properties of dense ceramic samples were studied.The first-order phase transitions were observed at temperatures near 700 K.The influence of the processing conditions on the morphology,temperature of phase transitions,and dielectric parameters was observed.In some ceramics effect of dielectric relaxation was observed at high temperatures.This effect was explained by the contribution from ionic transport due to the oxygen vacancies creation during high temperature sintering.
