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Experimental study on real-time monitoring of surrounding rock 3D wave velocity structure and failure zone in deep tunnels
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作者 Hongyun Yang Chuandong Jiang +4 位作者 Yong Li Zhi Lin Xiang Wang Yifei Wu Wanlin Feng 《International Journal of Mining Science and Technology》 2026年第2期423-437,共15页
An innovative real-time monitoring method for surrounding rock damage based on microseismic time-lapse double-difference tomography is proposed for delayed dynamic damage identification and insufficient detection of a... An innovative real-time monitoring method for surrounding rock damage based on microseismic time-lapse double-difference tomography is proposed for delayed dynamic damage identification and insufficient detection of adverse geological conditions in deep-buried tunnel construction.The installation techniques for microseismic sensors were optimized by mounting sensors at bolt ends which significantly improves signal-to-noise ratio(SNR)and anti-interference capability compared to conventional borehole placement.Subsequently,a 3D wave velocity evolution model that incorporates construction-induced disturbances was established,enabling the first visualization of spatiotemporal variations in surrounding rock wave velocity.It finds significant wave velocity reduction near the tunnel face,with roof and floor damage zones extending 40–50 m;wave velocities approaching undisturbed levels at 15 m ahead of the working face and on the laterally undisturbed side;pronounced spatial asymmetry in wave velocity distribution—values on the left side exceed those on the right,with a clear stress concentration or transition zone located 10–15 m;and systematically lower velocities behind the face than in front,indicating asymmetric rock damage development.These results provide essential theoretical support and practical guidance for optimizing dynamic construction strategies,enabling real-time adjustment of support parameters,and establishing safety early warning systems in deep-buried tunnel engineering. 展开更多
关键词 Deep-buried tunnel Microseismic monitoring wave velocity tomography Surrounding rock damage zone Real-time monitoring
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The Application Effect of Cardiac Rehabilitation Therapy in Patients with Chronic Heart Failure and Its Impact on Pulse Wave Velocity
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作者 Xin Huo Nanhua Yang +3 位作者 Donglai Li Jianfeng Zhang Hui Huang Shengyong Yang 《Journal of Clinical and Nursing Research》 2025年第4期349-355,共7页
Objective:To evaluate the effectiveness of cardiac rehabilitation therapy in the treatment of patients with chronic heart failure(CHF).Methods:76 patients with CHF who were treated in the hospital from January 2023 to... Objective:To evaluate the effectiveness of cardiac rehabilitation therapy in the treatment of patients with chronic heart failure(CHF).Methods:76 patients with CHF who were treated in the hospital from January 2023 to December 2024 were selected and randomly divided into two groups using a random number table.The experimental group(38 patients)received cardiac rehabilitation therapy,while the reference group(38 patients)received conventional drug therapy.The total effective rate,cardiac function indicators,lung function indicators,and pulse wave velocity(PWV)were compared between the two groups.Results:The total effective rate was higher in the experimental group than in the reference group.After treatment,the cardiac and lung function indicators were better in the experimental group than in the reference group,and the PWV was lower in the experimental group(P<0.05).Conclusion:Cardiac rehabilitation therapy for patients with CHF can improve treatment efficacy,enhance cardiopulmonary function,and regulate PWV levels,with high professionalism and feasibility. 展开更多
关键词 Cardiac rehabilitation therapy Chronic heart failure Cardiopulmonary function Pulse wave velocity
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The Effectiveness of Shallow Surface Geophysical Methods in Shear Wave Velocity Derivation
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作者 Dewan Mohammad Enamul Haque A. S. M. Woobaidullah 《Journal of Civil Engineering and Architecture》 2018年第8期573-585,共13页
Shear wave velocity Vs is measured by the surface geophysical survey like MASW (multi-channel surface wave analysis) or RWM (refraction wave method) and by the subsurface method like PS logging. PS logging and RWM... Shear wave velocity Vs is measured by the surface geophysical survey like MASW (multi-channel surface wave analysis) or RWM (refraction wave method) and by the subsurface method like PS logging. PS logging and RWM are direct methods to derive shear wave velocity and MASW retrieves shear wave through the inversion of the surface wave. In this work, the effectiveness of surface methods (MASW and RWM) is compared with PS logging in determining shear wave velocity. For this purpose, shear wave velocity results Vs30 of 12 PS logging and MASW surveys conducted in Mymensingh Municipality in Bangladesh have been utilized. Additionally, the shear wave velocity results of three PS logging have been compared with the refraction profiles of RWM survey conducted in Rooppur nuclear power plant site in Bangladesh. The relative discrepancy between RWM and PS logging is found less (ranges from -3.92 to 0.93) compared to MASW and PS logging (+/-0.88 to 33.92). The correlation coefficient of Vs30 derived from RWM and PS logging is observed much better (0.60) compared to MASW and PS logging (0.40). The result is good considering the lateral lithologic variability and inherent differences among techniques. It is evident from the comparison that the RWM can be used as a cost-effective alternative to traditional borehole PS logging method for Vs30 determination and thus the number of down-hole logging tests might be significantly reduced. 展开更多
关键词 Shear wave velocity surface wave velocity shallow seismic survey inversion.
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Shear wave velocity is a useful marker for managing nonalcoholic steatohepatitis 被引量:32
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作者 Akihiko Osaki Tomoyuki Kubota +11 位作者 Takeshi Suda Masato Igarashi Keisuke Nagasaki Atsunori Tsuchiya Masahiko Yano Yasushi Tamura Masaaki Takamura Hirokazu Kawai Satoshi Yamagiwa Toru Kikuchi Minoru Nomoto Yutaka Aoyagi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第23期2918-2925,共8页
AIM:To investigate whether a noninvasive measurement of tissue strain has a potential usefulness for management of nonalcoholic steatohepatitis(NASH).METHODS:In total 26 patients,23 NASHs and 3 normal controls were en... AIM:To investigate whether a noninvasive measurement of tissue strain has a potential usefulness for management of nonalcoholic steatohepatitis(NASH).METHODS:In total 26 patients,23 NASHs and 3 normal controls were enrolled in this study.NASH was staged based on Brunt criterion.At a region of interest(ROI),a shear wave was evoked by implementing an acoustic radiation force impulse(ARFI),and the propagation velocity was quantif ied.RESULTS:Shear wave velocity(SWV) could be reproducibly quantified at all ROIs in all subjects except for 4 NASH cases,in which a reliable SWV value was not calculated at several ROIs.An average SWV of 1.34 ± 0.26 m/s in fibrous stage 0-1 was significantly slower than 2.20 ± 0.74 m/s and 2.90 ± 1.01 m/s in stages 3 and 4,respectively,but was not significantly different from 1.79 ± 0.78 m/s in stage 2.When a cutoff value was set at 1.47 m/s,receiver operating characteristic analysis showed significance to dissociate stages 3 and 4 from stage 0-1(P=0.0092) with sensitivity,specificity and area under curve of 100%,75% and 94.2%,respectively.In addition,the correlation between SWV and hyaluronic acid was significant(P<0.0001),while a tendency toward negative correlation was observed with serum albumin(P=0.053).CONCLUSION:The clinical implementation of ARFI provides noninvasive repeated evaluations of liver stiffness at an arbitrary position,which has the potential to shed new light on NASH management. 展开更多
关键词 Nonalcoholic steatohepatitis ULTRASOUND Liver stiffness measurement Shear wave velocity Acoustic radiation force impulse
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Shear wave velocity-based liquefaction evaluation in the great Wenchuan earthquake: a preliminary case study 被引量:9
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作者 Zhou Yanguo Chen Yunmin Ling Daosheng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第2期231-239,共9页
The great Wenchuan earthquake(Ms=8.0)in 2008 caused severe damage in the western part of the Chengdu Plain.Soil liquefaction was one of the major causes of damage in the plain areas,and proper evaluation of liquefacti... The great Wenchuan earthquake(Ms=8.0)in 2008 caused severe damage in the western part of the Chengdu Plain.Soil liquefaction was one of the major causes of damage in the plain areas,and proper evaluation of liquefaction potential is important in the definition of the seismic hazard facing a given region and post-earthquake reconstruction.In this paper,a simplified procedure is proposed for liquefaction assessment of sandy deposits using shear wave velocity(V),and soil liquefaction from the Banqiao School site was preliminarily investigated after the earthquake.Boreholes were made at the site and shear wave velocities were measured both by SASW and down-hole methods.Based on the in-situ soil information and V profiles,the liquefaction potential of this site was evaluated.The results are reasonably consistent with the actual field behavior observed after the earthquake,indicating that the proposed procedure is effective.The possible effects of gravel and fines contents on liquefaction of sandy soils were also briefly discussed. 展开更多
关键词 LIQUEFACTION Wenchuan earthquake shear wave velocity spectral analysis of surface waves(SASW) hazarddefinition
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Shear wave velocity-based evaluation and design of stone column improved ground for liquefaction mitigation 被引量:7
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作者 Zhou Yanguo Sun Zhengbo +2 位作者 Chen Jie Chen Yunmin Chen Renpeng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2017年第2期247-261,共15页
The evaluation and design of stone column improvement ground for liquefaction mitigation is a challenging issue for the state of practice. In this paper, a shear wave velocity-based approach is proposed based on the w... The evaluation and design of stone column improvement ground for liquefaction mitigation is a challenging issue for the state of practice. In this paper, a shear wave velocity-based approach is proposed based on the well-defined correlations of liquefaction resistance (CRR)-shear wave velocity (V)-void ratio (e) of sandy soils, and the values of parameters in this approach are recommended for preliminary design purpose when site specific values are not available. The detailed procedures of pre- and post-improvement liquefaction evaluations and stone column design are given. According to this approach, the required level of ground improvement will be met once the target V of soil is raised high enough (i.e., no less than the critical velocity) to resist the given earthquake loading according to the CRR-V relationship, and then this requirement is transferred to the control of target void ratio (i.e., the critical e) according to the V-e relationship. As this approach relies on the densification of the surrounding soil instead of the whole improved ground and is conservative by nature, specific considerations of the densification mechanism and effect are given, and the effects of drainage and reinforcement of stone columns are also discussed. A case study of a thermal power plant in Indonesia is introduced, where the effectiveness of stone column improved ground was evaluated by the proposed V-based method and compared with the SPT-based evaluation. This improved ground performed well and experienced no liquefaction during subsequent strong earthquakes. 展开更多
关键词 Liquefaction mitigation Stone column Shear wave velocity Void ratio DENSIFICATION Ageing effect
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Fracturing process and effect of fracturing degree onwave velocity of a crystalline rock 被引量:7
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作者 Charalampos Saroglou Vasileios Kallimogiannis 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第5期797-806,共10页
The present paper investigates the effect of fracturing degree on P-and S-wave velocities in rock.The deformation of intact brittle rocks under loading conditions is characterized by a microcracking procedure,which oc... The present paper investigates the effect of fracturing degree on P-and S-wave velocities in rock.The deformation of intact brittle rocks under loading conditions is characterized by a microcracking procedure,which occurs due to flaws in their microscopic structure and propagates through the intact rock,leading to shear fracture.This fracturing process is of fundamental significance as it affects the mechanical properties of the rock and hence the wave velocities.In order to determine the fracture mechanism and the effect of fracturing degree,samples were loaded at certain percentages of peak strength and ultrasonic wave velocity was recorded after every test.The fracturing degree was recorded on the outer surface of the sample and quantified by the use of the indices P;(traces of joints/m),P;(traces of joints/m;) and P;(length of fractures/m;).It was concluded that the wave velocity decreases exponentially with increasing fracturing degree.Additionally,the fracturing degree is described adequately with the proposed indices.Finally,other parameters concerning the fracture characteristics,rock type and scale influence were found to contribute to the velocity decay and need to be investigated further. 展开更多
关键词 wave velocity FRACTURING Crack initiation DAMAGE GRANITE
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Ankle-brachial index and brachial-ankle pulse wave velocity are risk factors for ischemic stroke in patients with type 2 diabetes 被引量:5
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作者 Ting Li Xiu-juan Wu +3 位作者 Xiao-min Chen Si-bo Wang Kang-ding Liu Ying-qi Xing 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第11期1853-1859,共7页
The incidence of ischemic stroke in patients with diabetes is increasing. While brachial-ankle pulse wave velocity (BaPWV) and ankle-bra- chial index (ABI) are known to be associated with ischemic cardiovascular a... The incidence of ischemic stroke in patients with diabetes is increasing. While brachial-ankle pulse wave velocity (BaPWV) and ankle-bra- chial index (ABI) are known to be associated with ischemic cardiovascular and cerebrovascular diseases, whether these measures predict the risk of ischemic cerebrovascular disease in diabetic patients remains unclear. 117 patients with type 2 diabetes were enrolled in this study. According to the results of head magnetic resonance imaging, the patients were divided into a diabetes-only group (n = 55) and a diabetes and ischemic stroke group (n = 62). We then performed ABI and BaPWV examinations for all patients. Compared with the diabe- tes-only group, we found decreased ABI and increased BaPWV in the diabetes and ischemic stroke group. Multivariate logistic regression analyses revealed that BaPWV and ABI were risk factors for ischemic stroke in patients with type 2 diabetes. Our findings indicate that decreased ABI and increased BaPWV are objective indicators of increased risk of ischemic stroke in patients with type 2 diabetes. 展开更多
关键词 nerve regeneration brain injury ischemic stroke type 2 diabetes ankle-brachial index brachial-ankle pulse wave velocity magnetic resonance imaging low-density lipoprotein high-density lipoprotein transcranial Doppler ultrasonography carotid ultrasound scans neural regeneration
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Association of Estimated Pulse Wave Velocity and the Dynamic Changes in Estimated Pulse Wave Velocity with All-Cause Mortality among Middle-Aged and Elderly Chinese 被引量:4
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作者 LIU Han Rui LI Chen Yang +5 位作者 XIA Xue CHEN Shu Feng LU Xiang Feng GU Dong Feng LIU Fang Chao HUANG Jian Feng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2022年第11期1001-1011,共11页
Objective We aimed to clarify the association between estimated pulse wave velocity(ePWV)and the changes in ePWV with all-cause mortality among middle-aged and elderly Chinese.Methods Data were obtained from the China... Objective We aimed to clarify the association between estimated pulse wave velocity(ePWV)and the changes in ePWV with all-cause mortality among middle-aged and elderly Chinese.Methods Data were obtained from the China Health and Retirement Longitudinal Study(CHARLS)from 2011-2018.The ePWV was calculated using an equation that included age and mean blood pressure(MBP).The ΔePWV was assessed as the difference in ePWV between the first two waves.Cox proportional hazard models were used to determine the association between ePWV and ΔePWV with all-cause mortality after adjustment for potential confounders.Results Of 13,116 participants during a median follow-up of 7.0 years,1,356 deaths occurred.An increased ePWV was independently associated with all-cause mortality.The hazard ratio[95% confidence interval(CI)]for participants from the 1^(st)-4^(th) quartile groups was 1.00,1.69(1.31-2.18),3.09(2.44-3.91),and 8.54(6.78-10.75),respectively.Each standard deviation(SD)increment of ePWV increased the risk of all-cause mortality by 132%.Furthermore,theΔePWV was significantly associated with a 1.28-fold(95%CI,1.18-1.38)risk of all-cause mortality per SD increment.Conclusion This cohort study provided novel evidence from a Chinese population that an increased ePWV or progression of the ePWV was independently associated with all-cause mortality,which highlighted the importance of mitigating ePWV progression in clinical practice. 展开更多
关键词 Arterial stiffness Estimated pulse wave velocity MORTALITY COHORT
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Micro-failure process and failure mechanism of brittle rock under uniaxial compression using continuous real-time wave velocity measurement 被引量:4
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作者 WU Zhi-jun WANG Zhi-yang +2 位作者 FAN Li-feng WENG Lei LIU Quan-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期556-571,共16页
In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indi... In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage.A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing.Based on which,the effective elastic parameters are inferred by a transverse isotropic constitutive model,and the evolutions of the crack density are inversed using a self-consistent damage model.It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack. 展开更多
关键词 elastic wave velocity brittle rock failure uniaxial compression test continuous real-time measurement anisotropic damage evolution theory and modelling
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Fracture evolution and localization effect of damage in rock based on wave velocity imaging technology 被引量:4
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作者 ZHANG Yan-bo YAO Xu-long +5 位作者 LIANG Peng WANG Ke-xue SUN Lin TIAN Bao-zhu LIU Xiang-xin WANG Shan-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第9期2752-2769,共18页
By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emis... By utilizing wave velocity imaging technology,the uniaxial multi-stage loading test was conducted on siltstone to attain wave velocity imagings during rock fracture.Based on the time series parameters of acoustic emissions(AE),joint response characteristics of the velocity field and AE during rock fracture were analyzed.Moreover,the localization effect of damage during rock fracture was explored by applying wave velocity imagings.The experimental result showed that the wave velocity imagings enable three-dimensional(3-D)visualization of the extent and spatial position of damage to the rock.A damaged zone has a low wave velocity and a zone where the low wave velocity is concentrated tends to correspond to a severely damaged zone.AE parameters and wave velocity imagings depict the changes in activity of cracks during rock fracture from temporal and spatial perspectives,respectively:the activity of cracks is strengthened,and the rate of AE events increases during rock fracture;correspondingly,the low-velocity zones are gradually aggregated and their area gradually increases.From the wave velocity imagings,the damaged zones in rock were divided into an initially damaged zone,a progressively damaged zone,and a fractured zone.During rock fracture,the progressively damaged zone and the fractured zone both develop around the initially damaged zone,showing a typical localization effect of the damage.By capturing the spatial development trends of the progressively damaged zone and fractured zone in wave velocity imagings,the development of microfractures can be predicted,exerting practical significance for determining the position of the main fracture. 展开更多
关键词 rock mechanics acoustic emission(AE) wave velocity imaging technology tempo-spatial evolution characteristics localization effect of damage
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Relationship between the Plasma Fibulin-1 Levels,Pulse Wave Velocity,and Vascular Age in Asymptomatic Hyperuricemia 被引量:3
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作者 Yu SANG Kai-min MAO +4 位作者 Yi HUANG Xiao-fen WU Xing-fen WANG Lei RUAN Cun-tai ZHANG 《Current Medical Science》 SCIE CAS 2021年第1期94-99,共6页
Fibulin-1(FBLN-1),an elastin-associated extracellular matrix protein,has been found in blood and may play a role in the pathophysiological processes leading to cardiovascular disease(CVD).We aimed to investigate the r... Fibulin-1(FBLN-1),an elastin-associated extracellular matrix protein,has been found in blood and may play a role in the pathophysiological processes leading to cardiovascular disease(CVD).We aimed to investigate the relationship between fibulin-1 levels and the risk of CVD by evaluating vascular age derived from the Framingham Heart Study and brachial-ankle Pulse Wave Velocity(baPWV)in patients with asymptomatic hyperuricemia(AHU).In total,66 patients with AHU and 66 gender-and age-matched healthy individuals were enrolled.The plasma fibulin-1 levels were measured by immunochemistry.Patients with AHU presented significantly higher vascular age[median(interquartile range):54(22)vs.48(14)years,P=0.01]and baPWV[mean±SD:1373±223 vs.1291±177 cm/s,P=0.02]than the healthy subjects;however,no significant difference was observed in the plasma fibulin-1 level between the patients with AHU and healthy subjects[median(interquartile range):4018(3838)vs.3099(3405)ng/mL,P=0.31].A correlation between fibulin-1 levels and baPWV was observed only in patients with AHU(r=0.29,P=0.02);and there was also a suggestively statistically significant correlation between fibulin-1 levels and vascular age(r=0.22,P=0.08).However,these associations were rendered insignificant after adjustments for potential confounders.In healthy subjects,no correlation was observed between fibulin-1 levels and CVD risk.This study reveals that plasma fibulin-1 levels may reflect the CVD risk in patients with AHU,but the relationship is not robust. 展开更多
关键词 fibulin-1 cardiovascular risk vascular age brachial-ankle pulse wave velocity asymptomatic hyperuricemia
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Forward prediction for tunnel geology and classification of surrounding rock based on seismic wave velocity layered tomography 被引量:3
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作者 Bin Liu Jiansen Wang +2 位作者 Senlin Yang Xinji Xu Yuxiao Ren 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第1期179-190,共12页
Excavation under complex geological conditions requires effective and accurate geological forward-prospecting to detect the unfavorable geological structure and estimate the classification of surround-ing rock in fron... Excavation under complex geological conditions requires effective and accurate geological forward-prospecting to detect the unfavorable geological structure and estimate the classification of surround-ing rock in front of the tunnel face.In this work,a forward-prediction method for tunnel geology and classification of surrounding rock is developed based on seismic wave velocity layered tomography.In particular,for the problem of strong multi-solution of wave velocity inversion caused by few ray paths in the narrow space of the tunnel,a layered inversion based on regularization is proposed.By reducing the inversion area of each iteration step and applying straight-line interface assumption,the convergence and accuracy of wave velocity inversion are effectively improved.Furthermore,a surrounding rock classification network based on autoencoder is constructed.The mapping relationship between wave velocity and classification of surrounding rock is established with density,Poisson’s ratio and elastic modulus as links.Two numerical examples with geological conditions similar to that in the field tunnel and a field case study in an urban subway tunnel verify the potential of the proposed method for practical application. 展开更多
关键词 Tunnel geological forward-prospecting Seismic wave velocity Layered inversion Surrounding rock classification Artificial neural network(ANN)
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Inverting the rock mass P-wave velocity field ahead of deep buried tunnel face while borehole drilling 被引量:2
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作者 Liu Liu Shaojun Li +5 位作者 Minzong Zheng Dong Wang Minghao Chen Junbo Zhou Tingzhou Yan Zhenming Shi 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第5期681-697,共17页
Imaging the wave velocity field surrounding a borehole while drilling is a promising and urgently needed approach for extending the exploration range of the borehole point.This paper develops a drilling process detect... Imaging the wave velocity field surrounding a borehole while drilling is a promising and urgently needed approach for extending the exploration range of the borehole point.This paper develops a drilling process detection(DPD)system consisting of a multifunctional sensor and a pilot geophone installed at the top of the drilling rod,geophones at the tunnel face,a laser rangefinder,and an onsite computer.A weighted adjoint-state first arrival travel time tomography method is used to invert the P-wave velocity field of rock mass while borehole drilling.A field experiment in the ongoing construction of a deep buried tunnel in southwestern China demonstrated the DPD system and the tomography method.Time-frequency analysis of typical borehole drilling detection data shows that the impact drilling source is a pulse-like seismic exploration wavelet.A velocity field of the rock mass in a triangular area defined by the borehole trajectory and geophone receiving line can be obtained.Both the borehole core and optical image validate the inverted P-wave velocity field.A numerical simulation of a checkerboard benchmark model is used to test the tomography method.The rapid convergence of the misfits and consistent agreement between the inverted and observed travel times validate the P-wave velocity imaging. 展开更多
关键词 Deep buried tunnel wave velocity field Borehole drilling Tomography Rock mass
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Signal processing method for shear wave velocity measurement 被引量:2
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作者 侯兴民 曲淑英 时向东 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2007年第2期205-212,共8页
Soil shear wave velocity (SWV) is an important parameter in geotechnical engineering. To measure the soil SWV, three methods are generally used in China, including the single-hole method, cross-hole method and the s... Soil shear wave velocity (SWV) is an important parameter in geotechnical engineering. To measure the soil SWV, three methods are generally used in China, including the single-hole method, cross-hole method and the surface-wave technique. An optimized approach based on a correlation function for single-hole SWV measurement is presented in this paper. In this approach, inherent inconsistencies of the artificial methods such as negative velocities, and too-large and too-small velocities, are eliminated from the single-hole method, and the efficiency of data processing is improved. In addition, verification using the cross-hole method of upper measuring points shows that the proposed optimized approach yields high precision in signal processing. 展开更多
关键词 shear wave velocity single-hole method correlation function optimized approach
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Stepwise joint inversion of surface wave dispersion,Rayleigh wave ZH ratio,and receiver function data for 1D crustal shear wave velocity structure 被引量:9
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作者 Ping Zhang Huajian Yao 《Earthquake Science》 CSCD 2017年第5期229-238,共10页
Accurate determination of seismic velocity of the crust is important for understanding regional tectonics and crustal evolution of the Earth. We propose a stepwise joint linearized inversion method using surface wave ... Accurate determination of seismic velocity of the crust is important for understanding regional tectonics and crustal evolution of the Earth. We propose a stepwise joint linearized inversion method using surface wave dispersion, Rayleigh wave ZH ratio (i.e., ellipticity), and receiver function data to better resolve 1D crustal shear wave velocity (Vs) structure. Surface wave dispersion and Rayleigh wave ZH ratio data are more sensitive to absolute variations of shear wave speed at depths, but their sensi- tivity kernels to shear wave speeds are different and complimentary. However, receiver function data are more sensitive to sharp velocity contrast (e.g., due to the existence of crustal interfaces) and Vp/Vs ratios. The stepwise inversion method takes advantages of the complementary sensitivities of each dataset to better constrain the Vs model in the crust. We firstly invert surface wave dispersion and ZH ratio data to obtain a 1D smooth absolute vs model and then incorporate receiver function data in the joint inver- sion to obtain a finer Vs model with better constraints on interface structures. Through synthetic tests, Monte Carlo error analyses, and application to real data, we demonstrate that the proposed joint inversion method can resolve robust crustal Vs structures and with little initial model dependency. 展开更多
关键词 Joint inversion Receiver function Surfacewave dispersion Rayleigh wave ZH ratio· Shearwave velocity
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Serum Calcium Level is Associated with Brachial-ankle Pulse Wave Velocity in Middle-aged and Elderly Chinese 被引量:2
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作者 DENG Xin Ru ZHANG Yin Fei +8 位作者 WANG Tian Ge XU Bai Hui SUN Ji Chao ZHAO Lie Bin XU Min CHEN Yu Hong WANG Wei Qing BI Yu Fang LU Jie Li 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第8期594-600,共7页
Objective To study the relation between serum calcium level and elevated BaPWV in Chinese subjects. Methods The relation between serum calcium level and elevated BaPWV was studied in 9 615 subjects. The mean value of... Objective To study the relation between serum calcium level and elevated BaPWV in Chinese subjects. Methods The relation between serum calcium level and elevated BaPWV was studied in 9 615 subjects. The mean value of left and right BaPWV was analyzed. BaPWV was defined as high when it was31 752.5 cm/s (the upper quartile) either side. Results The BaPWV and its elevated percentage progressively increased across the quartiles of the serum calcium level (P〈0.05). The prevalence of elevated BaPWV was significantly higher in subjects of the second, third and highest quartiles than in those of the lowest quartile (26.9%, 28.4%, and 33.2%vs 23.7%, P=0.0116, P=0.0004, and P〈0.0001). Logistic regression analysis revealed that the risk of elevated BaPWV was 1.32- fold higher in subjects of the highest quartile than in those of the lowest quartile (OR=1.32, 95%CI:1.08-1.60). Conclusion The elevated serum calcium level is related to an elevated BaPWV and a higher risk of arterial stiffness, independent of conventional risk factors, in middle-aged and elderly Chinese subjects. 展开更多
关键词 CALCIUM Brachial-ankle pulse wave velocity Vascular stiffness
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Shear Wave Elastography of Invasive Ductal Carcinoma:Correlations between Shear Wave Velocity and Histological Prognostic Factors 被引量:2
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作者 Xiao-qing HU Li PENG +3 位作者 Max Wintermark Jafi Alyssa Lipson Yan-rong ZHANG Yuan GAO 《Current Medical Science》 SCIE CAS 2021年第1期173-179,共7页
The correlations between shear wave velocity(SWV)calculated from virtual touch tissue imaging quantification(VTIQ)technique and histological prognostic factors of invasive ductal carcinoma was investigated.A total of ... The correlations between shear wave velocity(SWV)calculated from virtual touch tissue imaging quantification(VTIQ)technique and histological prognostic factors of invasive ductal carcinoma was investigated.A total of 76 breast tumors histologically confirmed as invasive ductal carcinomas were included in this study.SWV values were measured by VTIQ for each lesion preoperatively or prior to breast biopsy.The maximum values were recorded for statistical analysis.Medical records were reviewed to determine tumor size,histological grade,lymph node status and immunohistochemical results.Tumor subtypes were categorized as luminal A,luminal B,human epidermal growth factor receptor 2(HER2)positive and triple negative.The correlations between SWV and histological prognostic factors were analyzed.It was found that tumor size showed positive association with SWV(r=0.465,P<0.001).Larger tumors had significantly higher SWV than smaller ones(P=0.001).Histological grade 1 tumors had significantly lower SWV values than those with higher histological grade(P=0.015).The Ki67 expression,tumor subtypes and lymph node status showed no statistically significant correlations with SWV,although triple negative tumors and lymph node-positive tumors showed higher SWV values.It was concluded that tumor size was significantly associated with SWV.Higher histological grade was associated with increased SWV.There was no statistically significant correlations between SWV and other histological prognostic factors. 展开更多
关键词 shear wave elastography virtual touch tissue imaging quantification shear wave velocity invasive ductal carcinoma histological prognostic factors
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The value of pulse wave velocity in the diagnosis of coronary heart disease 被引量:2
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作者 贾新未 刘铭雅 +1 位作者 魏盟 陆志刚 《Journal of Medical Colleges of PLA(China)》 CAS 2006年第4期254-257,共4页
Objective: Using receiver operating characteristics (ROC) curve to evaluate the value of pulse wave velocity (PWV) in the diagnosis of coronary heart disease (CHD). Methods: By using coronary angiography as golden dia... Objective: Using receiver operating characteristics (ROC) curve to evaluate the value of pulse wave velocity (PWV) in the diagnosis of coronary heart disease (CHD). Methods: By using coronary angiography as golden diagnostic standard of CHD, 218 patients were divided into both CHD group (n=121) and non-CHD group (n = 97). All these patients received PWV test. The efficacy of PWV of each artery segments in the diagnosis of CHD was evaluated by ROC curve. The sensitivity and specificity were calculated with the golden diagnostic standard of CHD. Results:The PWV of right carotid to femoral artery (Rc-f), left carotid to femoral artery (Lc-f), right radial to carotid artery (Rc-r), left radial to carotid artery (Lc-r) in CHD group were significantly higher than that of non-CHD group (9. 31±1. 75 vs 7.60±1.59, P<0. 01; 9. 02±1.71 vs 7. 52±1.50, P<0. 01; 8. 69±1. 37 vs 8. 00±1. 27, P<0. 01; 8.52±1. 03 vs 8. 03±1. 2, P<0. 01 respectively). However, the PWV of both right and left femoral to ankle artery (Rf-a and Lf-a) had no significant differences between the two groups. We then compared the area under curve (AUC) of each ROC(AUCROC) of PWV of Rc-f, Lc-f Rc-r and Lc-r to evaluate their diagnostic efficacy for CHD. We found that AUCROC of Rc-f PWV was the biggest (AUCROC = 0. 818), at the peak point of its ROC curve, the PWV was 8. 32 m/s. PWV>8. 32 m/s of Rc-f could predict the presence of CHD with a sensitivity of 79% and specificity of 77%. Conclusion: The PWV of Rc-f, Lc-f, Rc-r, Lc-r are significantly higher in CHD group than that in non-CHD group, and PWV of Rc-f is the most accurate in the detection of CHD. The PWV>8. 32 m/s of RC-F is a valuable predictor of CHD. 展开更多
关键词 coronary heart disease coronary angiography pulse wave velocity receiver operating characteristic DIAGNOSIS
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Brachial-ankle pulse wave velocity is an independent predictor of carotid artery atherosclerosis in the elderly 被引量:2
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作者 Jia-Yue Li Yu-Sheng Zhao 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2010年第3期157-160,共4页
Objective Brachial-ankle pulse wave velocity (baPWV) is widely used as a simple noninvasive measure of arterial softness. The aim of this study was to evaluate the usefulness of baPWV as a predictor of the carotid a... Objective Brachial-ankle pulse wave velocity (baPWV) is widely used as a simple noninvasive measure of arterial softness. The aim of this study was to evaluate the usefulness of baPWV as a predictor of the carotid artery atherosclerosis in the elderly. Methods A total of 721 elderly participants (mean ~ SD age, 70.3 -4- 5.6years) were enrolled in the current study. All participant underwent both baPWV measurement and B-mode ultrasound for the intima-media thickness. Carotid atherosclerosis (CAS) was defined as the present of carotid plaque or and/or intima media thickness for at least 1.1 mm. Results A multivariate logistic regression analysis reveals that age, sex, brachial-ankle pulse wave velocity, smoking and LDL-C level showed a significant correlation with the presence of CAS. The odds ratios of CAS associated with a 500cm/s increase of brachial-ankle pulse wave velocity were 2.378 [95% confidence interval, 1.36 to 4.00, P〈0.05], 3.733 [95% confidence interval, 1.729 to 8.058, P〈0.01], 4.438 [95% confidence interval, 1.659 to 11.803, P〈0.01]. The baPWV significantly correlated with IMT by bivariate correlation analysis (r=-0.39; p=0.001). After adjusting for factors influencing, baPWV all the same correlated with IMT (r=-0.35; p=0.001).Conclusion These results indicate that brachial-ankle PWV is an independent predictor of CAS in the elderly.It also means that the direct measurement of arterial stiffness by this simple method may be of great help for the evaluation of carotid artherosclerosis, at least in the elderly 展开更多
关键词 Aortic stiffness carotid arteriosclerosis pulse wave velocity
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