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| 1 | 为弥漫的甲状腺腺病理的评估的 ARFI elastography : 初步的结果显示文摘 AIM:To assess whether acoustic radiation force impulse(ARFI)elastography can differentiate normal from pathological thyroid parenchyma.METHODS:We evaluated 136 subjects(mean age 45.8±15.6 years,106 women and 30 men):44(32.3%) without thyroid pathology,48(35.3%)with BasedowGraves’disease(GD),37(27.2%)with chronic autoimmune thyroiditis(CAT;diagnosed by specific tests),4(2.9%)with diffuse thyroid goiter and 3(2.2%)cases with thyroid pathology induced by amiodarone.In all patients,10 elastographic measurements were made in the right thyroid lobe and 10 in the left thyroid lobe,using a 1-4.5 MHZ convex probe and a 4-9 MHz linear probe,respectively.Median values were calculated for thyroid stiffness and expressed in meters/second(m/s).RESULTS:Thyroid stiffness(TS)assessed by means of ARFI in healthy subjects(2±0.40 m/s)was significantly lower than in GD(2.67±0.53 m/s)(P<0.0001) and CAT patients(2.43±0.58 m/s)(P=0.0002),but the differences were not significant between GDvs CAT patients(P=0.053).The optimal cut-off value for the prediction of diffuse thyroid pathology was 2.36 m/s.For this cut-off value,TS had 62.5%sensitivity,79.5% specificity,87.6%predictive positive value,55.5% negative predictive value and 72.7%accuracy for the presence of diffuse thyroid gland pathology(AUROC=0.804).There were no significant differences between the TS values obtained with linear vs convex probes and when 5 vs 10 measurements were taken in each lobe(median values).CONCLUSION:ARFI seems to be a useful method for the assessment of diffuse thyroid gland pathology. | Ioan Sporea Roxana Sirli Simona Bota Mihaela Vlad Alina Popescu Ioana Zosin | 2012 | World Journal of Radiology2012，4，4： | 25 |
| 2 | MEMS仿生矢量水听器封装结构的设计与研究显示文摘针对MEMS仿鱼侧线矢量水听器提出三种封装结构,即采用聚氨酯材料制成的透声帽封装结构,透声帽内衬笼状支撑体的封装结构,透声帽内衬瓣状支撑体的封装结构。采用ANSYS有限元建立三维封装模型并进行模态仿真,得出其固有频率分别为875 Hz、2 926 Hz、3 006 Hz。采用Virtual.lab acoustic进行声衰减仿真并通过试验验证最终得出:内衬支撑体的封装结构,其有效带宽响应比无支撑体的透声帽封装结构宽2.2 kHz左右,同时,实验表明瓣状支撑体的收缩瓣状部分具有聚能效应,这种封装结构的水听器灵敏度比其他两种封装结构在相同频率点处高8 dB~12 dB。 | 李振 张国军 薛晨阳 薛南 刘宏 陈桂英 | 2013 | 传感技术学报2013，26，1： | 26 |
| 3 | Is ARFI elastography reliable for predicting fibrosis severity in chronic HCV hepatitis?显示文摘AIM:To determine whether acoustic radiation force impulse(ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus(HCV) hepatitis.METHODS:We performed a multicenter study including 274 subjects with HCV chronic hepatitis in which we compared ARFI with liver biopsy(LB).In each patient we performed LB(evaluated according to the Metavir score) and ARFI measurements(using a Siemens Acuson S2000TM ultrasound system:10 valid measurements were performed and median values were calculated and expressed in meters/second(m/s).RESULTS:A direct,strong,correlation(Spearman r = 0.707) was found between ARFI measurements and fibrosis(P < 0.0001).For predicting the presence of fibrosis(F ≥ 1 Metavir),significant fibrosis(F ≥ 2),severe fibrosis(F ≥ 3) and cirrhosis(F = 4),the cutoff values of 1.19,1.21,1.58 and 1.82 m/s were determined,respectively,liver stiffness measurements had 73%,84%,84% and 91% Se respectively;93%,91%,94%,90% Sp,respectively;with AUROCs of 0.880,0.893,0.908 and 0.937,respectively.CONCLUSION:ARFI measurement is a reliable method for predicting the severity of fibrosis in HCV | Ioan Sporea Roxana Sirli Simona Bota Carmen Fierbinteanu-Braticevici Alina Popescu Radu Badea Monica Lupsor Ana Petrisor Mirela Dnil | 2011 | World Journal of Radiology2011，3，7： | 24 |
| 4 | Characterization of focal liver masses using acoustic radiation force impulse elastography显示文摘AIM:To investigate the diagnostic performance of acoustic radiation force impulse(ARFI) elastography for characterizing focal liver mass by quantifying their stiffness.METHODS:This prospective study included 62 patients with a focal liver mass that was well visualized on conventional ultrasonography performed in our institution from February 2011 to November 2011.Among them,12 patients were excluded for ARFI measurement failure due to a lesion that was smaller than the region of the interest and at an inaccessible location(deeper than 8 cm)(n = 7) or poor compliance to hold their breath as required(n = 5).Finally,50 patients with valid ARFI measurements were enrolled.If a patient had multiple liver masses,only one mass of interest was chosen.The masses were diagnosed by histological examination or clinical diagnostic criteria.During ultrasonographic evaluation,stiffness,expressed as velocity,was checked 10 times per focal liver mass and the surrounding liver parenchyma.RESULTS:After further excluding three masses that were non-diagnostic on biopsy,a total of 47 focal mass lesions were tested,including 39(83.0%) malignant masses [24 hepatocellular carcinomas(HCC),seven cholangiocellular carcinomas(CCC),and eight liver metastases] and eight(17.0%) benign masses(five hemangiomas and three focal nodular hyperplasias,FNH).Thirty-seven(74.0%) masses were confirmed by histological examination.The mean velocity was 2.48 m/s in HCCs,1.65 m/s in CCCs,2.35 m/s in metastases,1.83 m/s in hemangiomas,and 0.97 m/s in FNHs.Although considerable overlap was still noted between malignant and benign masses,significant differences in ARFI values were observed between malignant and benign masses(mean 2.31 m/s vs 1.51 m/s,P = 0.047),as well as between HCCs and benign masses(mean 2.48 m/s vs 1.51 m/s,P = 0.006).The areas under the receiver operating characteristics curves(AUROC) for discriminating the malignant masses from benign masses was 0.724(95%CI,0.566-0.883,P = 0.048),and the AUROC for discriminating HCCs from benign masses was 0.813(95%CI,0.649-0.976,P = 0.008).To maximize the sum of sensitivity and specificity,an ARFI value of 1.82 m/s was selected as the cutoff value to differentiate malignant from benign liver masses.Furthermore,the cutoff value for distinguishing HCCs from benign masses was also determined to be 1.82 m/s.The diagnostic performance of the sum of the ARFI values for focal liver masses and the surrounding liver parenchyma to differentiate liver masses improved(AUROC = 0.853;95%CI,0.745-0.960;P = 0.002 in malignant liver masses vs benign ones and AUROC = 0.948;95%CI,0.896-0.992,P < 0.001 in HCCs vs benign masses).CONCLUSION:ARFI elastography provides additional information for the differential diagnosis of liver masses.However,our results should be interpreted in clinical context,because considerable overlap in ARFI values existed among liver masses. | Hana Park Jun Yong Park Do Young Kim Sang Hoon Ahn Chae Yoon Chon Kwang-Hyub Han Seung Up Kim | 2013 | World Journal of Gastroenterology2013，19，2： | 22 |
| 5 | 航天器声振动力学环境响应分析显示文摘动力学环境试验技术已得到了广泛的应用,但是动力学环境预示技术还没有得到很好的重视和发展。文章在简要概述了统计能量法(SEA)的基础上,以某卫星为例,划分为26个子系统和97个连接,对整星的宽带声振力学环境的响应进行了估计。经过与试验结果的对比,验证了上述方法的可行性。 | 谢久林 杨松 张俊刚 耿丽艳 贾雅琦 | 2006 | 航天器环境工程2006，23，2： | 21 |
| 6 | Features of infrared thermal image and radiation temperature of coal rocks loaded显示文摘Experimental study discovered that: (i) coal rocks and sandstone in the course of loading have three types of infrared thermal image features and three types of infrared radiation temperature features; (ii) infrared detection is comparable with acoustic emission detection and electrical resistance detection. Generally, the infrared forewarning of coal rocks’ failure comes later than that of acoustic and electrical resistance, but the infrared radiation temperature forewarning of coal burst comes earlier. On the basis of comprehensive study and analysis, it was suggested that stress nearby 0.79 σ c should be taken as the stress-caution-zone for rock mass failure, ground pressure and its disasters monitoring. | 吴立新 王金庄 | 1998 | Science China Earth Sciences1998，41，2： | 19 |
| 7 | Combined acoustic radiation force impulse, aminotransferase to platelet ratio index and Forns index assessment for hepatic fibrosis grading in hepatitis B显示文摘AIM: To investigate the combined diagnostic accuracy of acoustic radiation force impulse(ARFI), aspartate aminotransferase to platelet ratio index(APRI) and Forns index for a non-invasive assessment of liver fibrosis in patients with chronic hepatitis B(CHB). METHODS: In this prospective study, 206 patients had CHB with liver fibrosis stages F0-F4 classified by METAVIR and 40 were healthy volunteers were measured by ARFI, APRI and Forns index separately or combined as indicated. RESULTS: ARFI, APRI or Forns index demonstrated a significant correlation with the histological stage(all P < 0.001). According to the AUROC of ARFI and APRI for evaluating fibrotic stages more than F2, ARFI showed an enhanced diagnostic accuracy than APRI(P < 0.05). The combined measurement of ARFI and APRI exhibited better accuracy than ARFI alone when evaluating ≥ F2 fibrotic stage(Z = 2.77, P = 0.006). Combination of ARFI, APRI and Forns index did not obviously improve the diagnostic accuracy compared to the combination of ARFI and APRI(Z = 0.958, P = 0.338). CONCLUSION: ARFI + APRI showed enhanced diagnostic accuracy than ARFI or APRI alone for significant liver fibrosis and ARFI + APRI + Forns index shows the same effect with ARFI + APRI. | Chang-Feng Dong Jia Xiao Ling-Bo Shan Han-Ying Li Yong-Jia Xiong Gui-Lin Yang Jing Liu Si-Min Yao Sha-Xi Li Xiao-Hua Le Jing Yuan Bo-Ping Zhou George L Tipoe Ying-Xia Liu | 2016 | World Journal of Hepatology2016，8，14： | 18 |
| 8 | Noninvasive assessment of liver fibrosis in patients with chronic hepatitis B显示文摘Infection with hepatitis B virus is an important healthproblem worldwide:it affects more than 350 millionpeople and is a leading cause of liver-related morbidity,accounting for 1 million deaths annually.Hepatic fibrosis is a consequence of the accumulation of extracellular matrix components in the liver.An accurate diagnosis of liver fibrosis is essential for the management of chronic liver disease.Liver biopsy has been considered the gold standard for diagnosing disease,grading necroinflammatory activity,and staging fibrosis.However,liver biopsy is unsuitable for repeated evaluations because it is invasive and can cause major complications,including death.Several noninvasive evaluations have been introduced for the assessment of liver fibrosis:serum biomarkers,combined indices or scores,and imaging techniques including transient elastography,acoustic radiation force impulse,real-time tissue elastography,and magnetic resonance elastography.Here,we review the recent progress of noninvasive assessment of liver fibrosis in patients with chronic hepatitis B.Most noninvasive evaluations for liver fibrosis have been validated first in patients with chronic hepatitis C,and later in those with chronic hepatitis B.The establishment of a noninvasive assessment of liver fibrosis is urgently needed to aid in the management of this leading cause of chronic liver disease. | Masaru Enomoto Hiroyasu Morikawa Akihiro Tamori Norifumi Kawada | 2014 | World Journal of Gastroenterology2014，20，34： | 16 |
| 9 | Uniaxial experimental study of the acoustic emission and deformation behavior of composite rock based on 3D digital image correlation(DIC)显示文摘In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3 D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0?–45?specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60?–90?specimens gradually increased during the loading process. When the anisotropic angle θincreased from 0?to 90?, the peak strength, peak strain,and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories:tensile fracture across the discontinuities(θ = 0?–30?), slid-ing failure along the discontinuities(θ = 45?–75?), and tensile-split along the discontinuities(θ = 90?). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0?–45?specimens and was almost the same as that of the θ = 60?–90?specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0?–30?specimens appeared in the rock matrix approximately parallel to the loading direction,while in the θ = 45?–90?specimens it appeared at the hard and weak rock layer interface. | Jian-Long Cheng Sheng-Qi Yang Kui Chen Dan Ma Feng-Yuan Li Li-Ming Wang | 2017 | Acta Mechanica Sinica2017，33，6： | 13 |
| 10 | Noninvasive diagnosis of cirrhosis:A review of different imaging modalities显示文摘Progressive hepatic fibrosis can lead to cirrhosis,so its early detection is fundamental.Staging fibrosis is also critical for prognosis and management.The gold standard for these aims is liver biopsy,but it has several drawbacks,as it is invasive,expensive,has poor acceptance,is prone to inter observer variability and sampling errors,has poor repeatability,and has a risk of complications and mortality.Therefore,non-invasive imaging tests have been developed.This review mainly focuses on the role of transient elastography,acoustic radiation force impulse imaging,and magnetic resonance-based methods for the noninvasive diagnosis of cirrhosis. | Riccardo De Robertis Mirko D'Onofrio Emanuele Demozzi Stefano Crosara Stefano Canestrini Roberto Pozzi Mucelli | 2014 | World Journal of Gastroenterology2014，20，23： | 12 |
| 11 | Rare Earth Effects on Adhesion of Cr_2O_3 Oxide Scale Formed on Surface of Co-40Cr Alloy显示文摘Isothermal and cyclic oxidation behaviors of Co 40Cr alloy at 1000 ℃ in air were studied. Scanning electron microscopy (SEM) was used to examine the oxide scale formed on the surface of the alloy. By comparing the oxidation behaviors of Co 40Cr alloy and its 3×10 16 and 3×10 17 Y +/cm 2 implanted specimens, it was found that the resistant to oxidation property of Co 40Cr was greatly improved due to the implantation of yttrium. Acoustic emission was used to study the distribution of defects at the interface between the scale and alloy. Raman spectrum was also used to study the stress status in chromic scale formed on the surface of Co 40Cr with and without yttrium. The main reason for the improvement of resistant to oxidation property of Y doped Co 40Cr probably is that yttrium can segregate to Cr 2O 3 grain boundaries and change the scale′s growing mechanism and mechanical property. Most importantly, Y implantation decreases the size and number of interfacial defects and the residual stress in the scale, and remarkably enhances the adhesion of chromia scale with Co 40Cr substrate. | 靳惠明 张林楠 李美栓 李铁藩 | 2001 | Journal of Rare Earths2001，19，1： | 12 |
| 12 | Application of acoustic radiation force impulse imaging for the evaluation of focal liver lesion elasticity显示文摘BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a new elastography method for the evaluation of tissue stiffness. This study aims to evaluate the performance of ARFI in noninvasive assessment of the tissue stiffness of focal liver lesion (FLL) and to explore its potential value in the differential diagnosis of FLL. METHODS: ARFI was performed in 140 patients with 154 FLLs, which included 28 hemangiomas (ANGIs), 14 focal nodular hyperplasias (FNHs), 61 hepatocellular carcinomas (HCCs), 39 metastases and 12 cholangiocellular carcinomas (CCCs). Virtual touch tissue quantification (VTTQ) values were obtained, analyzed and compared. The area under the receiver operating characteristic curve (AUROC) and optimal cut-off values were obtained using a receiver operating characteristic (ROC) curve analysis to assess diagnostic performance. All cases were definitively diagnosed using histopathology, CT, MRI or contrast-enhanced ultrasound. RESULTS: The VTTQ median values of ANGI, FNH, HCC metastasis and CCC were 1.30, 1.80, 2.52, 3.08 and 3.89 m/s respectively. A significant increase in the VTTQ values of different lesions was observed: ANGI | Ping Zhang Ping Zhou Shuang-Ming Tian Ying Qian Jin Deng Lu Zhang | 2013 | Hepatobiliary & Pancreatic Diseases International2013，12，2： | 11 |
| 13 | Nearfield acoustic holography based on the equivalent source method显示文摘On the basis of the nearfield acoustic holography (NAH) based on the distributed source boundary point method (DSBPM), a novel NAH based on the equivalent source method (ESM) is proposed. The theoretical model of the proposed method is established at first. And then, the error sensitivity and the reconstruction problems of a multi-source acoustic field and a semi-free acoustic field are analyzed, and the corresponding treatment methods are proposed. Subsequently, an experiment on a speaker is investigated to validate the feasibility and correctness of the method. In the method, no discretization is needed on the boundary of the vibrating body. The acoustic field is predicted directly by a set of weighted equivalent sources located inside the vibrating body. Therefore, the variable interpolation, the treatments of singular integrals and non-uniqueness of solutions in the characteristic wave number are avoided. Additionally, the method is adapted to arbitrary-shaped source, so it is really a meshless method. Furthermore, there are such merits as the simple principle, the high calculation efficiency and precision. It is valuabe for the NAH to be applied in the practical engineering field. | BI Chuanxing CHEN Xinzhao CHEN Jian ZHOU Rong | 2005 | Science China(Technological Sciences)2005，48，3： | 11 |
| 14 | Liver fibrosis evaluation by ARFI and APRI in chronic hepatitis C显示文摘AIM:To explore the value of liver fibrosis assessment by acoustic radiation force impulse(ARFI)and the AST/PLT ratio index(APRI)in chronic hepatitis C patients.METHODS:One hundred and twenty eight patients with chronic hepatitis C were examined using ARFI elastometry and APRI,calculated according to known formulae.The gold standard of liver biopsy was referred;ROC curve analysis was used to assess all ARFI and APRI values.The corresponding cut-off values,sensitivities,and specificities were calculated and compared.In addition,the correlation of liver fibrosis stages in chronic hepatitis C patients with ARFI measurements and APRI were also tested to evaluate significant data.RESULTS:The values of ARFI in S1-S4 were 1.23±0.34 m/s,1.48±0.43 m/s,2.06±0.45 m/s,and 2.30±0.87 m/s.The values of APRI in S1-S4 were 0.31±0.45 m/s,0.28±0.38 m/s,0.58±0.59 m/s and0.65±0.34 m/s.ARFI(r=0.649,P<0.05)showed a better correlation with liver fibrosis stages in chronic hepatitis C than APRI(r=0.478,P<0.05).The areas under the ROC curves for ARFI and APRI were 0.775and 0.721 for stages≥S2,0.901 and 0.787 for stages≥S3,and 0.792 and 0.780 for S=4,respectively.CONCLUSION:Both ARFI and APRI could evaluate liver fibrosis stages in chronic hepatitis C.ARFI is more accurate than the APRI index. | Su-Mei Li Guang-Xia Li Dong-Mei Fu Yu Wang Li-Qun Dang | 2014 | World Journal of Gastroenterology2014，20，28： | 11 |
| 15 | Acoustic radiation force impulse of the liver显示文摘Acoustic radiation force impulse(ARFI)imaging is a new and promising ultrasound-based diagnostic technique that,evaluating the wave propagation speed,allows the assessment of the tissue stiffness.ARFI is implemented in the ultrasound scanner.By short-duration acoustic radiation forces(less than 1 ms),localized displacements are generated in a selected region of interest not requiring any external compression so reducing the operator dependency.The generated wave scan provides qualitative or quantitative(wave velocity values)responses.Several non-invasive methods for assessing the staging of fibrosis are used,in order to avoid liver biopsy.Liver function tests and transient elastography are non-invasive,sensitive and accurate tools for the assessment of liver fibrosis and for the discrimination between cirrhotic and non-cirrhotic liver.Many published studies analyse ARFI performance and feasibility in studying diffuse liver diseases and compare them to other diagnostic imaging modalities such as conventional ultrasonography and transient elastography.Solid focal liver lesions,both benign and malignant,are common findings during abdominal examinations.The accurate characterization and differential diagnosis are important aims of all the imaging modalities available today.Only few papers describe the application of ARFI technology in the study of solid focal liver lesions,with different results.In the present study,the existing literature,to the best of our knowledge,about ARFI application on diffuse and focal liver pathology has been evaluated and results and statistical analyses have been compared,bringing to the conclusion that ARFI can be used in the study of the liver with similar accuracy as transient elastography in diagnosing significant fibrosis or cirrhosis and has got some advantages in respect to transient elastography since it does not require separate equipment,better displays anatomical structures and measurements can be successfully carried out almost in every patient. | Mirko D'Onofrio Stefano Crosara Riccardo De Robertis Stefano Canestrini Emanuele Demozzi Anna Gallotti Roberto Pozzi Mucelli | 2013 | World Journal of Gastroenterology2013，19，30： | 9 |
| 16 | A prediction of the acoustic field of a vibrating box by FEM-BEM显示文摘A method based on Holmholtz equation is presented to predict thc acoustic radiation of a vibrating box by combining the finite clement method (FEM) with boundary element method (BEM). The prediction formulation is valid for all frequencies if an extra equation is added. The acoustic field of a vibrating box has been calculated and measured. The effectiveness of the method has been proved by test results. | YU Xingzhuo FANG Xing and ZHOU Yu (Department of Mechanical Engtheering I. Huazhong University of Science and Technology. Wuhan 430074) | 1995 | Chinese Journal of Acoustics1995，14，1： | 9 |
| 17 | Space-time evolution rules of acoustic emission location of unloaded coal sample at different loading rates显示文摘By using MTS815 rock mechanics test system,a series of acoustic emission(AE) location experiments were performed under unloading confining pressure,increasing the axial stress.The AE space-time evolution regularities and energy releasing characteristics during deformation and failure process of coal of different loading rates are compared,the influence mechanism of loading rates on the microscopic crack evolution were studied,combining the AE characteristics and the macroscopic failure modes of the specimens,and the precursory characteristics of coal failure were also analyzed quantitatively.The results indicate that as the loading rate is higher,the AE activity and the main fracture will begin earlier.The destruction of coal body is mainly the function of shear strain at lower loading rate and tension strain at higher rate,and will transform from brittleness to ductility at critical velocities.When the deformation of the coal is mainly plasticity,the amplitude of the AE ringing counting rate increases largely and the AE energy curves appear an obvious ''step'',which can be defined as the first failure precursor point.Statics of AE information shows that the strongest AE activity begins when the axial stress level was 92-98%,which can be defined as the other failure precursor point.As the loading rate is smaller,the coal more easily reaches the latter precursor point after the first one,so attention should be aroused to prevent dynamic disaster in coal mining when the AE activity reaches the first precursor point. | Ai Ting Zhang Ru Liu Jianfeng Ren Li | 2012 | International Journal of Mining Science and Technology2012，22，6： | 9 |
| 18 | Fractional Fourier domain hopped communication method based on chirp modulation for underwater acoustic channels显示文摘To improve the data rate of underwater acoustic frequency-hopped communications, frequency hopping is applied to different orders of fractional Fourier domain(Fr FD), to enable non-intrusive, bandwidth-limited acoustic communications.An Fr FD frequency-hopped communication method based on chirp modulation, namely multiple chirp shift keying-Fr FD hopping(MCSK-Fr FDH), is proposed for underwater acoustic channels. Validated by both simulations and experimental results, this method can reach a bandwidth efficiency twice more than conventional frequency-hopped methods with the same data rate and anti-multipath capability, suggesting that the proposed method achieves a better performance than the traditional frequencyhopped communication in underwater acoustic communication channels. Results also show that in practical scenarios, the MCSKFr FDH system with longer symbol length performs better at the low signal-to-noise ratio(SNR), while the system with larger frequency sweeping range performs better at a high SNR. | Xingbin Tu Xiaomei Xu Zheguang Zou Liangliang Yang Jianming Wu | 2017 | Journal of Systems Engineering and Electronics2017，28，3： | 9 |
| 19 | Investigating the mechanical and acoustic emission characteristics of brittle failure around a circular opening under uniaxial loading显示文摘The size of underground openings in rock masses in metal mines is critical to the performance of the openings. In this study, the mechanical and acoustic emission (AE) characteristics of brittle rock-like specimens containing a circular opening with different ratios of opening diameter to sample size λ (λ = 0.1, 0.13, 0.17, 0.2, and 0.23) were investigated under uniaxial compression with AE monitoring. The results indicate that the opening size strongly affected the peak strength and the elastic modulus. Crack initiation first started from the upper surface of the specimens, not from the periphery of the openings. Tensile and shear cracks coexisted on the roof and floor of the specimens, whereas tensile cracks were dominant on the two sides. The fracture mode of samples with openings was partially affected by the relative size of the pillars and openings. The AE response curves (in terms of counts, cumulative energy, cumulative counts, and b-value) show that brittle failure was mainly a progressive process. Moreover, the AE information corresponded well with microcrack evolution in the samples and thus can be used to predict sample failure. | Peng Li Fen-hua Ren Mei-feng Cai Qi-feng Guo Hao-fei Wang Kang Liu | 2019 | International Journal of Minerals,Metallurgy and Materials2019，26，10： | 9 |
| 20 | Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity显示文摘A measurement system for acoustic resonant spectroscopy (ARS) is estab-lished,and the effects of resonant cavity geometry,inner perturbation samples and envi-ronmental temperature on the ARS are investigated. The ARSs of the small samples with various sizes and acoustic properties are measured. The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid tem-perature in the cylindrical cavity,while the resonant amplitude increases. At certain pres-sure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid. The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity. At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples. The resonant frequencies of the porous rock samples are smaller than those of the com-pacted samples if other acoustic parameters are the same. As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradu-ally for the compacted rocks while decreases for the unconsolidated rocks. Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small. In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively. These results may provide basic reference for the ex-periment study of rock acoustic properties in a low frequency using ARS. | CHEN Dehua1,2,WANG Xiuming2,3,CONG Jiansheng1,XU Delong1,SONG Yanjie1 & MA Shuilong4 1. Department of Geophysics,Daqing Petroleum Institute,Daqing 163318,China 2. Institute of Acoustics,Chinese Academy of Sciences,Beijing 100080,China 3. Division of Petroleum,Australian Commonwealth Scientific and Industrial Research Organization,Bent-ley WA 6102,Australia 4. Daqing Testing and Technology Services Corporation,Daqing 163153,China | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，6： | 8 |
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