The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, th...The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing.展开更多
目的比较锁定钢板与双切口双钢板内固定治疗复杂性胫骨平台骨折(CTPF)的临床疗效。方法回顾性分析2015年5月至2017年4月榆林市第一医院骨科收治的146例CTPF患者的临床资料,按照治疗方法不同分为A组和B组,每组各73例。A组采用双切口双钢...目的比较锁定钢板与双切口双钢板内固定治疗复杂性胫骨平台骨折(CTPF)的临床疗效。方法回顾性分析2015年5月至2017年4月榆林市第一医院骨科收治的146例CTPF患者的临床资料,按照治疗方法不同分为A组和B组,每组各73例。A组采用双切口双钢板内固定,B组采用锁定钢板内固定,对比两组患者手术时间、术中出血量、住院时间、完全负重下地时间、骨折愈合时间、膝关节开始功能锻炼时间、术后胫骨平台内翻角(TPA)和内侧后倾角(PA)的度数、术后随访膝关节功能恢复情况及术后并发症发生情况。结果 A组患者术后膝关节开始功能锻炼时间短于B组(5.69±1.08 d vs.15.36±1.22 d,P<0.05),A组患者术后完全负重下地时间及骨折愈合时间均长于B组,组间比较差异具有统计学意义(18.25±1.86周vs.11.36±1.37周,28.21±1.58周vs.18.52±1.33周,P<0.05)。两组患者术后12个月TPA、PA的度数比较,差异无统计学意义(P>0.05)。两组患者膝关节功能评分表(HSS)优良率分别为86.3%(63/73)、87.7%(64/73),组间比较差异无统计学意义(P>0.05)。A组患者术后膝关节僵直率为1.4%(1/73),低于B组的16.4%(12/73)(P<0.05)。结论锁定钢板与双切口双钢板内固定治疗CTPF的临床疗效相似,均可获得较为满意的固定稳定性,且愈后下肢力线好,膝关节功能恢复率较高,但仍各具优缺点,临床需根据实际情况选择合理术式。展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 10304012).
文摘The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity is introduced to study the Lamb wave's potential application in liquid sensing. Considering the measuring of ideal nonviscous liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously. Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient, the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies show that the Lamb wave sensors array can be potential in liquid sensing.
文摘目的比较锁定钢板与双切口双钢板内固定治疗复杂性胫骨平台骨折(CTPF)的临床疗效。方法回顾性分析2015年5月至2017年4月榆林市第一医院骨科收治的146例CTPF患者的临床资料,按照治疗方法不同分为A组和B组,每组各73例。A组采用双切口双钢板内固定,B组采用锁定钢板内固定,对比两组患者手术时间、术中出血量、住院时间、完全负重下地时间、骨折愈合时间、膝关节开始功能锻炼时间、术后胫骨平台内翻角(TPA)和内侧后倾角(PA)的度数、术后随访膝关节功能恢复情况及术后并发症发生情况。结果 A组患者术后膝关节开始功能锻炼时间短于B组(5.69±1.08 d vs.15.36±1.22 d,P<0.05),A组患者术后完全负重下地时间及骨折愈合时间均长于B组,组间比较差异具有统计学意义(18.25±1.86周vs.11.36±1.37周,28.21±1.58周vs.18.52±1.33周,P<0.05)。两组患者术后12个月TPA、PA的度数比较,差异无统计学意义(P>0.05)。两组患者膝关节功能评分表(HSS)优良率分别为86.3%(63/73)、87.7%(64/73),组间比较差异无统计学意义(P>0.05)。A组患者术后膝关节僵直率为1.4%(1/73),低于B组的16.4%(12/73)(P<0.05)。结论锁定钢板与双切口双钢板内固定治疗CTPF的临床疗效相似,均可获得较为满意的固定稳定性,且愈后下肢力线好,膝关节功能恢复率较高,但仍各具优缺点,临床需根据实际情况选择合理术式。
