The delay compensation method plays an essential role in maintaining the stability and achieving accurate real-time hybrid simulation results. The effectiveness of various compensation methods in different test scenar...The delay compensation method plays an essential role in maintaining the stability and achieving accurate real-time hybrid simulation results. The effectiveness of various compensation methods in different test scenarios, however, needs to be quantitatively evaluated. In this study, four compensation methods （i.e., the polynomial extrapolation, the linear acceleration extrapolation, the inverse compensation and the adaptive inverse compensation） are selected and compared experimentally using a frequency evaluation index （FEI） method. The effectiveness of the FEI method is first verified through comparison with the discrete transfer fimction approach for compensation methods assuming constant delay. Incomparable advantage is further demonstrated for the FEI method when applied to adaptive compensation methods, where the discrete transfer function approach is difficult to implement. Both numerical simulation and laboratory tests with predefined displacements are conducted using sinusoidal signals and random signals as inputs. Findings from numerical simulation and experimental results demonstrate that the FEI method is an efficient and effective approach to compare the performance of different compensation methods, especially for those requiring adaptation of compensation parameters.展开更多
A method for extracting optical parameters of plastics materials based on terahertz time domain spectroscopy is presented. The transmission-type Terahertz Time-Domain Spectroscopy(THz TDS) system is adopted to detect ...A method for extracting optical parameters of plastics materials based on terahertz time domain spectroscopy is presented. The transmission-type Terahertz Time-Domain Spectroscopy(THz TDS) system is adopted to detect the refractive index and extinction coefficient on different plastic materials. Then the corresponding spectral information is obtained by Fourier transform of the terahertz time domain waveform of the sampling points, including the corresponding amplitude and phase information of the waveform. The optical parameter extraction model is built. By using the simplex optimization method, the curves of the refractive index and extinction coefficient for the plastic material are obtained. The experimental samples are made of different plastic parallel plate materials. The experimental results show that the optimization of optical parameters can improve their extraction accuracy, and the error of refractive index is ±0.005. Extraction technology with the simplex optimization method of optical parameter based on THz TDS can help to extract the optical parameters of engineering plastics. It is of great significance for the research of terahertz nondestructive testing.展开更多
目的检测急性冠脉综合征(acute coronary syndrome,ACS)患者血清长链非编码RNA X染色体失活特异转录物(LncRNA X inactivate-specific transcript,LncRNA XIST)和微小RNA(miR)-330-3p水平,分析二者与心脏自主神经功能的关系。方法选取2...目的检测急性冠脉综合征(acute coronary syndrome,ACS)患者血清长链非编码RNA X染色体失活特异转录物(LncRNA X inactivate-specific transcript,LncRNA XIST)和微小RNA(miR)-330-3p水平,分析二者与心脏自主神经功能的关系。方法选取2020年2月~2021年6月在华北石油管理局总医院诊断为ACS的患者156例,包括不稳定型心绞痛(unstable angina,UA)80例(UA组)和急性心肌梗死(acute myocardial infarction,AMI)76例(AMI组);另选取同期体检健康者100例作为对照组。实时荧光定量PCR法检测受试者血清LncRNA XIST和miR-330-3p水平;24 h动态心电图检测受试者心率变异性(heart rate variability,HRV)时域指标[包括:24 h内正常R-R间期标准差(SDNN)、每5 min R-R间期平均值的标准差(SDANN)、每5 min R-R间期标准差的平均值(SDNN index)、相邻R-R间期之差的均方根(RMSSD)及相邻R-R间期相差>50 ms心搏数占总心搏数的百分比(PNN50)]以及Pearson法分析ACS患者血清LncRNA XIST和miR-330-3p水平与HRV时域指标的相关性。结果与对照组比较,UA组和AMI组血清LncRNA XIST(1.37±0.26,1.69±0.31 vs 1.09±0.22)水平升高(F=113.587,P=0.000),miR-330-3p(0.82±0.15,0.53±0.12 vs 1.03±0.18)及SDANN(115.96±19.57 ms,98.96±16.57 ms vs 133.43±21.01 ms),SDNN(113.84±15.26 ms,101.84±11.22 ms vs 136.41±31.53 ms),SDNN index(54.68±6.72 ms,46.73±5.14 ms vs 64.68±10.64 ms),RMSSD(27.48±5.62 ms,21.37±3.64 ms vs 36.48±8.62 ms)和PNN50(7.58%±2.83%,4.18%±1.13%vs 10.72%±3.21%)水平均降低(F=54.923~225.201,均P=0.000),差异均有统计学意义。与UA组比较,AMI组血清LncRNA XIST水平升高(t=10.792,P<0.05),miR-330-3p及SDANN,SDNN,SDNN index,RMSSD和PNN50水平降低,差异有统计学意义(t=4.743~16.538,均P<0.05);ACS患者血清LncRNA XIST与SDNN index,RMSSD和PNN50呈负相关(r=-0.465,-0.532,-0.542,均P<0.05);miR-330-3p与SDNN index,RMSSD和PNN50呈正相关(r=0.471,0.562,0.561,均P<0.05)。结论ACS患者血清LncRNA XIST水平升高,miR-330-3p水平降低,与心脏自主神经功能有关,可作为防治ACS的重要靶点。展开更多
基金National Natural Science Foundation of China under Grant No.51378107the Fundamental Research Funds for the Central Universities and Priority Academic Program Development of Jiangsu Higher Education Institutions under Grant No.KYLX-0158the National Natural Science Foundation under Grant No.CMMI-1227962
文摘The delay compensation method plays an essential role in maintaining the stability and achieving accurate real-time hybrid simulation results. The effectiveness of various compensation methods in different test scenarios, however, needs to be quantitatively evaluated. In this study, four compensation methods （i.e., the polynomial extrapolation, the linear acceleration extrapolation, the inverse compensation and the adaptive inverse compensation） are selected and compared experimentally using a frequency evaluation index （FEI） method. The effectiveness of the FEI method is first verified through comparison with the discrete transfer fimction approach for compensation methods assuming constant delay. Incomparable advantage is further demonstrated for the FEI method when applied to adaptive compensation methods, where the discrete transfer function approach is difficult to implement. Both numerical simulation and laboratory tests with predefined displacements are conducted using sinusoidal signals and random signals as inputs. Findings from numerical simulation and experimental results demonstrate that the FEI method is an efficient and effective approach to compare the performance of different compensation methods, especially for those requiring adaptation of compensation parameters.
基金National defense technical basic research project,Terahertz detection technology and application research on ceramic matrix composites(JSZL2015411C002)
文摘A method for extracting optical parameters of plastics materials based on terahertz time domain spectroscopy is presented. The transmission-type Terahertz Time-Domain Spectroscopy(THz TDS) system is adopted to detect the refractive index and extinction coefficient on different plastic materials. Then the corresponding spectral information is obtained by Fourier transform of the terahertz time domain waveform of the sampling points, including the corresponding amplitude and phase information of the waveform. The optical parameter extraction model is built. By using the simplex optimization method, the curves of the refractive index and extinction coefficient for the plastic material are obtained. The experimental samples are made of different plastic parallel plate materials. The experimental results show that the optimization of optical parameters can improve their extraction accuracy, and the error of refractive index is ±0.005. Extraction technology with the simplex optimization method of optical parameter based on THz TDS can help to extract the optical parameters of engineering plastics. It is of great significance for the research of terahertz nondestructive testing.
文摘目的检测急性冠脉综合征(acute coronary syndrome,ACS)患者血清长链非编码RNA X染色体失活特异转录物(LncRNA X inactivate-specific transcript,LncRNA XIST)和微小RNA(miR)-330-3p水平,分析二者与心脏自主神经功能的关系。方法选取2020年2月~2021年6月在华北石油管理局总医院诊断为ACS的患者156例,包括不稳定型心绞痛(unstable angina,UA)80例(UA组)和急性心肌梗死(acute myocardial infarction,AMI)76例(AMI组);另选取同期体检健康者100例作为对照组。实时荧光定量PCR法检测受试者血清LncRNA XIST和miR-330-3p水平;24 h动态心电图检测受试者心率变异性(heart rate variability,HRV)时域指标[包括:24 h内正常R-R间期标准差(SDNN)、每5 min R-R间期平均值的标准差(SDANN)、每5 min R-R间期标准差的平均值(SDNN index)、相邻R-R间期之差的均方根(RMSSD)及相邻R-R间期相差>50 ms心搏数占总心搏数的百分比(PNN50)]以及Pearson法分析ACS患者血清LncRNA XIST和miR-330-3p水平与HRV时域指标的相关性。结果与对照组比较,UA组和AMI组血清LncRNA XIST(1.37±0.26,1.69±0.31 vs 1.09±0.22)水平升高(F=113.587,P=0.000),miR-330-3p(0.82±0.15,0.53±0.12 vs 1.03±0.18)及SDANN(115.96±19.57 ms,98.96±16.57 ms vs 133.43±21.01 ms),SDNN(113.84±15.26 ms,101.84±11.22 ms vs 136.41±31.53 ms),SDNN index(54.68±6.72 ms,46.73±5.14 ms vs 64.68±10.64 ms),RMSSD(27.48±5.62 ms,21.37±3.64 ms vs 36.48±8.62 ms)和PNN50(7.58%±2.83%,4.18%±1.13%vs 10.72%±3.21%)水平均降低(F=54.923~225.201,均P=0.000),差异均有统计学意义。与UA组比较,AMI组血清LncRNA XIST水平升高(t=10.792,P<0.05),miR-330-3p及SDANN,SDNN,SDNN index,RMSSD和PNN50水平降低,差异有统计学意义(t=4.743~16.538,均P<0.05);ACS患者血清LncRNA XIST与SDNN index,RMSSD和PNN50呈负相关(r=-0.465,-0.532,-0.542,均P<0.05);miR-330-3p与SDNN index,RMSSD和PNN50呈正相关(r=0.471,0.562,0.561,均P<0.05)。结论ACS患者血清LncRNA XIST水平升高,miR-330-3p水平降低,与心脏自主神经功能有关,可作为防治ACS的重要靶点。
