In the exploration,tracking and positioning of underwater targets,it is necessary to perform frequency domain analysis and correlation calculation on the underwater acoustic signals of the target radiation.In a strong...In the exploration,tracking and positioning of underwater targets,it is necessary to perform frequency domain analysis and correlation calculation on the underwater acoustic signals of the target radiation.In a strong noise environment,the target signal may be overwhelmed by noise,resulting in an inability to effectively identify the target.Aiming at this problem,this paper presents a method of signal-noise separation by combining Fourier denoising with wavelet transform to realize underwater acoustic signal extraction in a strong noise environment.The combination algorithm of Fourier coefficient threshold adjustment and wavelet threshold transform is designed,and performance of the algorithm is tested.Simulation results show that the combination algorithm can effectively extract underwater acoustic signals when signal-to-noise ratio(SNR)is-15 dB,which can improve the SNR to 8.2 dB.展开更多
Objective:To observe the clinical effect of acupoint sticking therapy with Mian Tan Gao(facial paralysis paste)plus electroacupuncture(EA)for treating peripheral facial paralysis and its influence on patients'faci...Objective:To observe the clinical effect of acupoint sticking therapy with Mian Tan Gao(facial paralysis paste)plus electroacupuncture(EA)for treating peripheral facial paralysis and its influence on patients'facial nerve functions,facial disability index and clinical symptoms and signs.Methods:A total of 96 peripheral facial paralysis patients were allocated into an observation group,a medicine group and an EA group by simple randomization,with 32 cases in each group.Patients in the medicine group were treated with oral mecobalamine and prednisone acetate;patients in the EA group were treated with EA on the basis of the medicine treatment;while patients in the observation group were treated with acupoint sticking therapy with Mian Tan Gao(facial paralysis paste)plus EA.After 4-week treatment,the clinical efficacy,the adverse events,and the scores of House-Brackmann(H-B)facial nerve function grading scale,visual analog scale(VAS),clinical symptoms and signs,and facial disability index(FDI)were compared.Results:After 4-week treatment,the total effective rate was 96.9%in the observation group,higher than 68.7%in the medicine group and 75.0%in the EA group(both P<0.05).After 4-week treatment,the scores of H-B grading scale,VAS and clinical symptoms and signs in the three groups dropped significantly compared with those before treatment,and the scores in the observation group were lower than those in the medicine group and EA group(all P<0.05).After 4-week treatment,the facial disability index-physical function(FDIP)in the FDI in the three groups increased significantly,with a higher value in the observation group compared with that in the medicine group and EA group(both P<0.05).The facial disability index-social function(FDIS)in the FDI dropped significantly,with a lower score in the observation group compared with that in the medicine group and EA group(both P<0.05).However,the comparisons of the items above between the medicine group and the EA group showed no statistical significance(all P>0.05).The between-grou展开更多
基金Applied Basic Research Project of Shanxi Province(Nos.201601D011035,201701D121067)Higher Education Technology Innovation Project of Shanxi Province(No.201804011)。
文摘In the exploration,tracking and positioning of underwater targets,it is necessary to perform frequency domain analysis and correlation calculation on the underwater acoustic signals of the target radiation.In a strong noise environment,the target signal may be overwhelmed by noise,resulting in an inability to effectively identify the target.Aiming at this problem,this paper presents a method of signal-noise separation by combining Fourier denoising with wavelet transform to realize underwater acoustic signal extraction in a strong noise environment.The combination algorithm of Fourier coefficient threshold adjustment and wavelet threshold transform is designed,and performance of the algorithm is tested.Simulation results show that the combination algorithm can effectively extract underwater acoustic signals when signal-to-noise ratio(SNR)is-15 dB,which can improve the SNR to 8.2 dB.
文摘Objective:To observe the clinical effect of acupoint sticking therapy with Mian Tan Gao(facial paralysis paste)plus electroacupuncture(EA)for treating peripheral facial paralysis and its influence on patients'facial nerve functions,facial disability index and clinical symptoms and signs.Methods:A total of 96 peripheral facial paralysis patients were allocated into an observation group,a medicine group and an EA group by simple randomization,with 32 cases in each group.Patients in the medicine group were treated with oral mecobalamine and prednisone acetate;patients in the EA group were treated with EA on the basis of the medicine treatment;while patients in the observation group were treated with acupoint sticking therapy with Mian Tan Gao(facial paralysis paste)plus EA.After 4-week treatment,the clinical efficacy,the adverse events,and the scores of House-Brackmann(H-B)facial nerve function grading scale,visual analog scale(VAS),clinical symptoms and signs,and facial disability index(FDI)were compared.Results:After 4-week treatment,the total effective rate was 96.9%in the observation group,higher than 68.7%in the medicine group and 75.0%in the EA group(both P<0.05).After 4-week treatment,the scores of H-B grading scale,VAS and clinical symptoms and signs in the three groups dropped significantly compared with those before treatment,and the scores in the observation group were lower than those in the medicine group and EA group(all P<0.05).After 4-week treatment,the facial disability index-physical function(FDIP)in the FDI in the three groups increased significantly,with a higher value in the observation group compared with that in the medicine group and EA group(both P<0.05).The facial disability index-social function(FDIS)in the FDI dropped significantly,with a lower score in the observation group compared with that in the medicine group and EA group(both P<0.05).However,the comparisons of the items above between the medicine group and the EA group showed no statistical significance(all P>0.05).The between-grou
文摘以预处理的活性炭为载体、二氧化铈为修饰剂、NaBH_4为还原剂,制备了Pd_2Ni_3/C、Pd_(core)Ni_(shell)/C、Ni_(core)Pd_(shell)/C 3种不同结构的碱性燃料电池阳极催化剂。采用XPS、XRD、TEM表征了其结构及微观形貌,并通过电化学测试考察了其电化学性能。结果表明:NicorePdshell/C催化剂中n(Pd)∶n(Ni)=2∶3.3较接近理想比例(2∶3),催化剂颗粒分散均匀,粒径分布最窄,且平均粒径最小,为3.4 nm。电化学测试结果表明:在碱性环境下,Nicore Pdshell/C催化剂在100 m V/s扫描速度下,最高电流密度达到160 m A/cm2,在-0.5 V条件下,电流密度为2.80m A/cm2,其稳定性均优于Pd2Ni3/C和PdcoreNishell/C催化剂。
