Results 71 to 80 of about 8,084 (157)
Acoustic emission frequency spectrum characteristics of granite fissure water-induced slip [PDF]
Hydraulic shearing is an important method in the development of hot dry rock geothermal energy. Studying the differences in the acoustic emission spectrum during fault slip in hot dry rock reservoirs with and without fluid involvement is of great ...
Hanmo NAN +4 more
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Zhendong Ceshi yu Zhenduan为了识别含褶皱缺陷的风力机叶片主梁初始损伤临界状态，在流变学理论的基础上建立了疲劳损伤萌生区域温度场与应力场的定量关系，在已知初始损伤尺寸的条件下推导了初始损伤温度跃变判据，在平面应力假设的条件下推导了损伤萌生的临界声发射幅值和累积声发射数的函数关系。为了验证红外热像（infrared thermography，简称IR）方法识别初始损伤状态的有效性，制作带皱褶的玻璃纤维增强复合（glass fiber reinforced plastic，简称GFRP） 材料层合板试件进行疲劳拉伸实验 ...
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Three-dimensional omnidirectional characterization methods of rock anisotropic wave velocity and acoustic emission location optimization [PDF]
Rock failure and instability have been key research topics in rock mechanics domestically and internationally. Numerous geotechnical disasters, such as rock bursts and slope instability, are associated with these phenomena. Acoustic emission detection is
Conghao LI +5 more
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Gaoya dianqi, 2004 通过研究高压开关烧结触头结合面上超声波的传播特点发现,界面处的散射现象是造成超声C扫描图像不均匀的主要原因。在此基础上提出了超声C扫描图像形态滤波校正方法。试验结果表明,该法有效地校正了高压开关烧结触头的超声C扫描图像的不均匀现象,提高了超声无损检测的准确性。
曹宗杰, 陈怀东, 薛锦, 王裕文
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Zhongshan Daxue xuebao. Yixue kexue ban, 2015 【目的】 探讨超声造影（ＣＥＵＳ）在困难部位恶性肿瘤放射性粒子植入治疗中的应用价值。【方法】 超声造影引导下对２４例共３１个困难部位（肿瘤边缘与胆囊、肝门部、胃肠、左右门静脉主干或三支肝静脉、下腔静脉距离不足０．５ｃｍ）的恶性肿瘤行放射性碘粒子植入治疗术。分别于术前和术后１、３、６、１２月进行增强ＣＴ及超声造影随访。根据ＲＥＣＩＳＴ判定标准评价局部疗效，根据超声造影早期增强程度评估病灶血供变化。【结果】平均随访时间１１个月，范围１～４６个月。增强ＣＴ显示术后１、３、６、１２月总有效率分别为０％、７．７％、
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, 2008 目前,国内外在建立声发射参数和力学参数间的定量关系的研究相对较少,前人提出的两种理论模型都是基于一定的假设条件给出的,并没有得到充分的试验证明.同时,没有很好的利用两种模型来评价岩石类材料的强度和损伤.本文首先在MTS试验系统上对灰岩进行单轴受压破坏全过程的声发射试验研究,分析了其声发射特征.其次在试验结果的基础上,给出了应用两种模型的拟合结果,从而检验了两种模型的有效性和适用性.最后,应用Dai和Labuz模型计算得到了灰岩的损伤变量值,通过比较计算结果来判断灰岩的强度及损伤程度 ...
李庶林, 王明
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Mechanism analysis on anisotropic degradation of sandstone in freeze thaw environment based acoustic emission [PDF]
In the freeze-thaw environments, the fracturing of bedding rock poses a significant threat to the stability of the projects in cold regions, leading to potential engineering accidents.
Bing LIU +4 more
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He jishu实现对空间中子/伽马（n/γ）的精准甄别有利于空间辐射场的研究。传统的甄别方法受数据噪声影响较大，难以实现在星载探测器这样高噪声水平条件下进行n/γ甄别。为实现在不同噪声水平下n/γ的有效甄别，本研究提出了使用小波散射网络（Scattering Convolution Networks，SCN）结合MobileNetV4（MNv4）和Kolmogorov–Arnold Networks（KAN）模型的n/γ甄别的算法。研究选用Ø50 mm×50 mm的NaI（Tl ...
王 雨龙 +5 more
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Deformation and failure law and control of surrounding rock in the large section chamber of Ulan Mulun Coal Mine [PDF]
In response to the deformation and failure of surrounding rock in large section chamber underground roadways of coal mines, this study focuses on the sorting and filling of large section chamber underground roadways in Ulan Mulun coal mine.
BAO Shiji +5 more
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Guangtongxin yanjiu, 2011 文章介绍了两种补偿相位噪声的新技术,分别是补偿激光器相位噪声的数字前馈载波恢复算法和补偿非线性相位噪声的数字反向传播算法。其中数字前馈载波恢复算法能有效地提高能够容忍的激光器线宽;数字反向传播算法减少了非线性噪声,并能够大幅提高发射功率,以提高信噪比。
张自然 +6 more
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