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Analysis of quality factors for Rayleigh channel waves 被引量:5
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作者 杨小慧 曹思远 +2 位作者 李德春 于鹏飞 张浩然 《Applied Geophysics》 SCIE CSCD 2014年第1期107-114,118,共9页
To facilitate investigation of the effect of imperfect elastic dissipation on the propagation of Rayleigh-type channel waves and use of their quality factors in investigations of the properties of coal seams, a simple... To facilitate investigation of the effect of imperfect elastic dissipation on the propagation of Rayleigh-type channel waves and use of their quality factors in investigations of the properties of coal seams, a simple method for calculating the quality factor QR is proposed in this paper. Introduction of complex velocities into the dispersion function allows calculation of the dispersion function of Rayleigh-type channel waves in coal seams. By the control variable method, we analyzed changes in QR with changes in coal seam thickness and P- and S-wave Q-factors within the coal seam and adjacent rock layers. The numerical results show that the trend of the QR curve is consistent with the group velocity curve. The minimum QR value occurs at the Airy phase frequency; the Airy phase frequency decreases as coal seam thickness increases. The value of QR increases with increasing QS2(quality factor for S wave in coal seam). We can compensate for the absorption of Rayleigh-type channel waves using the computed QR curve. Inversion of the QR curve can also be used to predict the thicknesses and lithologies of coal seams. 展开更多
关键词 Coal seam RAYLEIGH channel wave DISPERSION curve attenuation quality factor
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Wave Attenuation Performance and the Influencing Factors of A Lower Arc-Plate Breakwater 被引量:7
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作者 LI Xue-yan WANG Qing +6 位作者 YOU Zai-jin GUO Wei-jun ZHANG Jun-bin ZHAN Chao ZHANG Zhi-chen WANG Li-xue LI Qin 《China Ocean Engineering》 SCIE EI CSCD 2020年第1期89-98,共10页
Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which conside... Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wave- generating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19 0.45. The transmission coefficients at relative submergences of 0.04, 0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods. 展开更多
关键词 arc-plate breakwater wave attenuation performance influencing factors VOF method
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基于D-Wave Advantage的量子退火公钥密码攻击算法研究
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作者 王潮 王启迪 +2 位作者 洪春雷 胡巧云 裴植 《计算机学报》 EI CAS CSCD 北大核心 2024年第5期1030-1044,共15页
D-Wave专用量子计算机的原理量子退火凭借独特的量子隧穿效应可跳出传统智能算法极易陷入的局部极值,可视为一类具有全局寻优能力的人工智能算法.本文研究了两类基于量子退火的RSA公钥密码攻击算法(分解大整数N=pq):一是将密码攻击数学... D-Wave专用量子计算机的原理量子退火凭借独特的量子隧穿效应可跳出传统智能算法极易陷入的局部极值,可视为一类具有全局寻优能力的人工智能算法.本文研究了两类基于量子退火的RSA公钥密码攻击算法(分解大整数N=pq):一是将密码攻击数学方法转为组合优化问题或指数级空间搜索问题,通过Ising模型或QUBO模型求解,提出了乘法表的高位优化模型,建立新的降维公式,使用D-Wave Advantage分解了 200万整数2269753.大幅度超过普渡大学、Lockheed Martin和富士通等实验指标,且Ising模型系数h范围缩小了 84%,系数J范围缩小了 80%,极大地提高了分解成功率,这是一类完全基于D-Wave量子计算机的攻击算法;二是基于量子退火算法融合密码攻击数学方法优化密码部件的攻击,采用量子退火优化CVP问题求解,通过量子隧穿效应获得比Babai算法更近的向量,提高了 CVP问题中光滑对的搜索效率,在D-Wave Advantage上实现首次50比特RSA整数分解.实验表明,在通用量子计算机器件进展缓慢情况下,D-Wave表现出更好的现实攻击能力,且量子退火不存在NISQ量子计算机VQA算法的致命缺陷贫瘠高原问题:算法会无法收敛且无法扩展到大规模攻击. 展开更多
关键词 RSA D-wave 量子退火 CVP 量子隧穿 整数分解 量子计算
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Risk Factors for COVID-19 Related Death during the First Three Waves of the Pandemic in an Epidemic Treatment Center at Dakar, Senegal 被引量:1
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作者 Moustapha Diop Papa Samba Ba +17 位作者 Viviane Marie Pierre Cisse Ndèye Aissatou Lakhe Betty Fall Moustapha Lo Ndong Essomba Bruce Wembulua Fatimata Wone Becaye Fall Khardiata Diallo-Mbaye Daye Ka Louise Fortes Ousmane Faye Ndongo Dia Khalifa Ababacar Wade Abdou Rajack Ndiaye Amadou Alpha Sall Moussa Seydi Mame Thierno Dieng 《Advances in Infectious Diseases》 2023年第2期117-131,共15页
Introduction-Objective: COVID-19 is a highly transmissible but often mild viral infection. However, some patients can present severe COVID-19 and subsequently die. The aim of the present study was to assess the risk f... Introduction-Objective: COVID-19 is a highly transmissible but often mild viral infection. However, some patients can present severe COVID-19 and subsequently die. The aim of the present study was to assess the risk factors for COVID-19 related death during the first three waves of the disease at the Epidemic Treatment Center (ETC) of Dakar Principal Hospital (DPH). Method: We conducted a descriptive and analytical perspective survival study from April 4, 2020 to September 25, 2021, including adult patients with COVID-19, hospitalized at the ETC of DPH. Log Rank test and multivariate Cox model were performed to identify risk factors for death. Results: We included 556 COVID-19 patients with mean age of 57 ± 17 years and a male-to-female ratio of 1.26. The number of deaths during one month of follow-up was 41, representing a cumulative risk of 7.4%. The log Rank test showed that being from the third wave (p = 0.0056), advanced age (p = 0.00098), presence of at least one comorbidity (p = 0.034), High blood pressure (p = 0.024), d-dimer level ≥ 1000 IU/L (p Conclusion: Our study showed that elderly and third-wave of COVID-19 patients were more at risk to die. Knowledge of risk factors for COVID-19 related death could improve the prognosis of these patients. 展开更多
关键词 COVID-19 waveS DEATH Risk factors DAKAR
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An Experimental Study on the Wave-Induced Pore Water Pressure Change and Relative Influencing Factors in the Silty Seabed
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作者 LI Anlong LUO Xiaoqiao +2 位作者 LIN Lin YE Qing LI Chunyu 《Journal of Ocean University of China》 SCIE CAS 2014年第6期911-916,共6页
In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heigh... In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heights respectively. The study showed that water waves propagating over silty seabed can induce significant change of pore water pressure, and the amplitude of pore pressure depends on depth of buried soil layer, clay content and wave height, which are considered as the three influencing factors for pore water pressure change. The pressure will attenuate according to exponential law with increase of soil layer buried depth, and the attenuation being more rapid in those soil layers with higher clay content and greater wave height. The pore pressure in silty seabed increases rapidly in the initial stage of wave action, then decreases gradually to a stable value, depending on the depth of buried soil layer, clay content and wave height. The peak value of pore pressure will increase if clay content or depth of buried soil layer decreases, or wave height increases. The analysis indicated that these soils with 5% clay content and waves with higher wave height produce instability in bed easier, and that the wave energy is mostly dissipated near the surface of soils and 5% clay content in soils can prevent pore pressure from dissipating immediately. 展开更多
关键词 wave action silty seabed pore water pressure development influencing factor
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Risk Factors for Severity and Mortality of Patients Hospitalized for COVID-19 during the 3rd Wave of the Epidemic-Sao Tome and Principe
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作者 Eula Carvalho Bakissy Pina +3 位作者 Rosa Neto Wrceley Lima Vanderley Bandeira Leonilde Carvalho 《Advances in Infectious Diseases》 2023年第2期303-322,共20页
Rationale: In the literature, some risk factors for severity and mortality from COVID-19 have been indicated. However, these factors can change, depending on the characteristics of the population and health services. ... Rationale: In the literature, some risk factors for severity and mortality from COVID-19 have been indicated. However, these factors can change, depending on the characteristics of the population and health services. In this sense, longitudinal studies can be useful for understanding local realities and subsidizing health actions based on these realities. Objective: To analyze the risk factors for severity and death in hospitalized patients with COVID-19. Methods: A retrospective cohort of patients with COVID-19 hospitalized from August 1 to October 16, 2021 (3<sup>rd</sup> wave of the pandemic), notified by the Department of Epidemiological Surveillance of Sao Tome and Principe. We employed measures of strength of associations for the analysis of exposure risk factors. Results: We analyzed 110 hospitalized patients (31.8% severe-critical and 68.2% non-severe). The risk factors for severe forms of COVID-19 were: being aged ≥60 years (RR = 3.3), being male (RR = 2), having comorbidities (RR = 2) and the risk increases to 10-fold for multicomorbidities, with emphasis on obesity, neoplasia, skin-muscle-surgical infection, dementia and to some degree CVD. 62.9% of patients with severe forms of the disease were not vaccinated. Risk factors for death among hospitalized and severe/critical cases, respectively, were having comorbidities (RR = 8 and 2.4) multicomorbidities (RR = 10 and 2.8 for those with 2 comorbidities and RR = 33.3 and 4 for those with 3 or 4 comorbidities), especially diabetes, dementia, neoplasia, cutaneous-muscular infection, and obesity. Although CVD was not associated with risk factors for death, these were the most frequently found among the severely hospitalized and deaths. In addition, important risk factors associated with death were not using corticoids (RR = 3.3, 230-fold risk) and not using anticoagulants-heparin (RR = 1.3, 30% risk) more compared to the severe cases that did use them. Most of the patients who died (63.2%) were not vaccinated. Moreover, having only 1 dose of the vaccine was a risk factor 1.9 times more for death among all hospitalized patients, but in the severe cases, there was no association between the variable vaccination and death. Among those hospitalized with 2 doses, it was a 0.5-fold protective factor among those hospitalized. The Delta variant of Sarscov-2 was the one found among severe cases and deaths investigated by genetic sequencing, with more exuberant clinical features compared to the other 2 previous vaccinations. Conclusion: Being elderly, male and presenting comorbidities, mainly multicomorbidities were the main characteristics associated with severity of COVID-19. On the other hand, comorbidities, and even worse, multicomorbidities, hospitalization for respiratory failure, lowered level of consciousness, no use of corticoid and no use of anticoagulation in critically ill patients, and not having at least 2 doses of vaccine for covid-19, were characteristics associated with death by COVID-19. These results will help inform healthcare providers so that the best interventions can be implemented to improve outcomes for patients with COVID-19. Public health interventions must be carefully tailored and implemented in these susceptible groups to reduce the risk of mortality in patients with COVID-19 and then the risk of major complications. Intensive and regular follow-up is needed to detect early occurrences of clinical conditions. 展开更多
关键词 Covid-19 3rd wave of the Epidemic Risk factors Death SEVERITY Sao Tomé and Principe
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SCATTERING OF SH-WAVE BY CRACKS ORIGINATING AT AN ELLIPTIC HOLE AND DYNAMIC STRESS INTENSITY FACTOR
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作者 刘殿魁 陈志刚 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2004年第9期1047-1056,共10页
The method of complex function and the method of Green's function are used to investigate the problem of SH-wave scattering by radial cracks of any limited length along the radius originating at the boundary of an... The method of complex function and the method of Green's function are used to investigate the problem of SH-wave scattering by radial cracks of any limited length along the radius originating at the boundary of an elliptical hole, and the solution of dynamic stress intensity factor at the crack tip was given. A Green's function was constructed for the problem, which is a basic solution of displacement field for an elastic half space containing a half elliptical gap impacted by anti-plane harmonic linear source force at any point of its horizontal boundary. With division of a crack technique, a series of integral equations can be established on the conditions of continuity and the solution of dynamic stress intensity factor can be obtained. The influence of an elliptical hole on the dynamic stress intensity factor at the crack tip was discussed. 展开更多
关键词 Fracture mechanics Green's function Integral equations SCATTERING Stress intensity factors Surface waves Crack tip Elastic half space Elliptic hole Griffith linear crack SH wave
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Effect of Load Power Factor on Electromechanical Wave Propagation in Ring Power System
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作者 MOHAMMED Heikal 《Computer Aided Drafting,Design and Manufacturing》 2008年第2期109-112,共4页
One-dimensional ring power system is discredited to a number of nodes each containing a generator with internal reactance and load branch of resistance and reactance with a certain power factor. When a disturbance occ... One-dimensional ring power system is discredited to a number of nodes each containing a generator with internal reactance and load branch of resistance and reactance with a certain power factor. When a disturbance occurs at any machine in the power system, simulative analysis is performed to verify how the variation of load power factor affecting the behavior of electromechanical wave propagation by using the MATLAB package, from which different situations are presented and discussed. These results show the type of load has no effect on the behavior of electromechanical wave propagation. 展开更多
关键词 electromechanical wave propagation one-dimensional power system continuum system load power factor MATLAB
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膝骨关节炎疼痛领域热点与前沿的可视化分析 被引量:2
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作者 赵盾 祁令臣 +1 位作者 徐金凡 邵敏 《中国组织工程研究》 CAS 北大核心 2025年第15期3280-3289,共10页
背景:疼痛是膝骨关节炎的主要症状,严重影响老年患者的生活质量。膝骨关节炎疼痛机制复杂,涉及多组织、多学科,需要可视化分析了解其主要内容与研究热点。目的:运用文献计量学可视化软件分析归纳膝骨关节炎疼痛领域的前沿内容和研究热... 背景:疼痛是膝骨关节炎的主要症状,严重影响老年患者的生活质量。膝骨关节炎疼痛机制复杂,涉及多组织、多学科,需要可视化分析了解其主要内容与研究热点。目的:运用文献计量学可视化软件分析归纳膝骨关节炎疼痛领域的前沿内容和研究热点。方法:从Web of Science核心合集(Web of Science Core Collection,WoSCC)中检索2014-2024年膝骨关节炎疼痛领域的相关文献,运用Citespace、VOSviewer和Bibliometrix R-package三个可视化软件进行文献计量与可视化分析。结果与结论:①膝骨关节炎疼痛研究的发文量呈现逐年递增的趋势;②美国、中国、澳大利亚是该领域10年内发文量排名前三的国家;波士顿大学、悉尼大学、弗洛里达大学是发文量前三的科研机构;《OSTEOARTHRITIS AND CARTILAGE》是出版该领域文献最多的期刊,《PAIN》则是该领域被引次数最多的期刊;发文量最多的作者是Fillingim Roger B,该领域的核心作者之间已经建立了一些稳定的团队,但国际性合作尚有欠缺;③膝骨关节炎疼痛患者的日常管理(运动、心理、智能管理)、疼痛的炎症机制、蛋白组学、联合用药、中枢敏化和疼痛调节是膝骨关节炎疼痛研究的重点内容;人工智能辅助、体外冲击波疗法、射频消融术、神经冷冻术、关节腔内注射血液或细胞制剂可能是该领域的研究前沿。 展开更多
关键词 VOSviewer软件 Citespace软件 Bibliometrix R-package 文献计量学 炎症因子 体外冲击波疗法 疼痛管理 神经阻滞 蛋白组学
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The change characteristics of the calculated wind wave fields near lateral boundaries with SWAN model
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作者 ZHANG Hongsheng ZHAO Jiachen +2 位作者 LI Penghui YUE Wenhan WANG Zhenxiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第1期96-105,共10页
Since the wind wave model Simulating Waves Nearshore (SWAN) cannot effectively simulate the wave fields near the lateral boundaries, the change characteristics and the distortion ranges of calculated wave factors in... Since the wind wave model Simulating Waves Nearshore (SWAN) cannot effectively simulate the wave fields near the lateral boundaries, the change characteristics and the distortion ranges of calculated wave factors including wave heights, periods, directions, and lengths near the lateral boundaries of calculation domain are carefully studied in the case of different water depths and wind speeds respectively. The calculation results show that the effects of the variety of water depth and wind speed on the modeled different wave factors near the lateral boundaries are different. In the case of a certain wind speed, the greater the water depth is, the greater the distortion range is. In the case of a certain water depth, the distortion ranges defined by the relative errors of wave heights, periods, and lengths are different from those defined by the absolute errors of the corresponding wave factors. Moreover, the distortion ranges defined by the relative errors decrease with the increase of wind speed; whereas the distortion ranges defined by the absolute errors change a little with the variety of wind speed. The distortion range of wave direction decreases with the increase of wind speed. The calculated wave factors near the lateral boundaries with the SWAN model in the actual physical areas, such as Lake Taihu and Lake Dianshan considered in this study, are indeed distorted if the calculation domains are not enlarged on the basis of actual physical areas. Therefore, when SWAN is employed to calculate the wind wave fields near the shorelines of sea or inland lakes, the appropriate approaches must be adopted to reduce the calculation errors. 展开更多
关键词 SWAN model wave factor change characteristic distortion range water depth wind speed lateral boundary
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卵巢良恶性肿瘤Notch1、Notch3和WAVE1的表达及与血清指标的关系
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作者 罗莎 王孟丽 易村犍 《海南医学院学报》 CAS 2015年第1期120-123,共4页
目的:研究Notch1、Notch3和WAVE1在卵巢良恶性肿瘤中的差异表达情况及其与血清指标的关系。方法:将2012年4月~2014年4月在我院就诊的60例卵巢癌患者纳入研究,同期在我院就诊的60例卵巢良性肿瘤患者纳入研究的对照组,采用Real-time PC... 目的:研究Notch1、Notch3和WAVE1在卵巢良恶性肿瘤中的差异表达情况及其与血清指标的关系。方法:将2012年4月~2014年4月在我院就诊的60例卵巢癌患者纳入研究,同期在我院就诊的60例卵巢良性肿瘤患者纳入研究的对照组,采用Real-time PCR检测肿瘤组织中Notch1、Notch3和WAVE1的mRNA含量,采用Western-blot检测肿瘤组织中Notch1、Notch3和WAVE1的蛋白含量,采用酶联免疫吸附法检测血清中转化生长因子-β1(TGF-β1)、基质金属蛋白酶2、9(MMP2、MMP9)的含量。结果:卵巢癌组织中Notch1、Notch3和WAVE1的mRNA和蛋白水平均高于对照组(P〈0.05);且FIGO分期越高,Notch1、Notch3和WAVE1的表达量越高(P〈0.05);卵巢癌患者血清中TGF-β1、MMP2、MMP9的含量高于卵巢良性肿瘤患者(P〈0.05),且TGF-β1、MMP2、MMP9含量均与Notch1、Notch3、WAVE1呈正相关。结论:卵巢癌组织中Notch1、Notch3和WAVE1表达量异常升高,且与血清中TGF-β1、MMP2、MMP9的含量具有良好的相关性。 展开更多
关键词 卵巢癌 NOTCH wave 基质金属蛋白酶 转化生长因子
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飞行人员动脉僵硬度及影响因素分析
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作者 刘峰舟 李倩 +6 位作者 王宁睿 黄莉 彭文华 潘欣 薛军辉 林伟 郑建勇 《空军军医大学学报》 2025年第1期100-104,110,共6页
目的分析我军飞行人员动脉僵硬度现状及其影响因素,为飞行人员个体化健康管理提供依据。方法回顾性分析西京医院空勤科162例住院飞行人员病历资料的一般特征,并采用多元线性回归分析颈股脉搏波传导速度(cfPWV)和脉搏波增强指数(AIx)的... 目的分析我军飞行人员动脉僵硬度现状及其影响因素,为飞行人员个体化健康管理提供依据。方法回顾性分析西京医院空勤科162例住院飞行人员病历资料的一般特征,并采用多元线性回归分析颈股脉搏波传导速度(cfPWV)和脉搏波增强指数(AIx)的影响因素。结果随着飞行人员年龄增长和飞行时间增加,cfPWV、AIx、中心动脉收缩压和中心动脉舒张压呈升高趋势;相关性分析发现:飞行人员cfPWV与年龄、站位腰围(WC)、体质量指数(BMI)、血压、总胆固醇、低密度脂蛋白、甘油三酯和飞行时间呈显著正相关,飞行人员AIx与年龄、WC、BMI、血压、空腹血糖、吸烟史和飞行时间呈显著正相关;多元线性回归分析发现,飞行人员cfPWV的显著影响因素有WC和中心动脉收缩压(P<0.05);飞行人员AIx的显著因素主要是年龄(P<0.05)。结论对中心动脉收缩压偏高、WC偏大的大龄飞行人员应当及时监测cfPWV和AIx指标,评估血管僵硬程度,及时开展针对性干预,降低心血管疾病发生风险。 展开更多
关键词 飞行人员 动脉僵硬度 脉搏波传导速度 影响因素
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Instability and Death of Spiral Wave in a Two-Dimensional Array of Hindmarsh-Rose Neurons 被引量:3
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作者 王春妮 马军 +1 位作者 唐军 李延龙 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第2期382-388,共7页
Spiral wave could be observed in the excitable media, the neurons are often excitable within appropriateparameters. The appearance and formation of spiral wave in the cardiac tissue is linked to monomorphic ventricula... Spiral wave could be observed in the excitable media, the neurons are often excitable within appropriateparameters. The appearance and formation of spiral wave in the cardiac tissue is linked to monomorphic ventriculartachycardia that can denervate into polymorphic tachycardia and ventricular fibrillation. The neuronal system oftenconsists of a large number of neurons with complex connections. In this paper, we theoretically study the transitionfrom spiral wave to spiral turbulence and homogeneous state (death of spiral wave) in two-dimensional array of theHindmarsh-Rose neuron with completely nearest-neighbor connections. In our numerical studies, a stable rotating spiralwave is developed and selected as the initial state, then the bifurcation parameters are changed to different values toobserve the transition from spiral wave to homogeneous state, breakup of spiral wave and weak change of spiral wave,respectively. A statistical factor of synchronization is defined with the mean field theory to analyze the transition fromspiral wave to other spatial states, and the snapshots of the membrane potentials of all neurons and time series of meanmembrane potentials of all neurons are also plotted to discuss the change of spiral wave. It is found that the sharpchanging points in the curve for factor of synchronization vs. bifurcation parameter indicate sudden transition fromspiral wave to other states. And the results are independent of the number of neurons we used. 展开更多
关键词 spiral wave factor of synchronization Hindmarsh-Rose neurons BIFURCATION
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New Developments in Structural Health Monitoring Based on Diagnostic Lamb Wave 被引量:9
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作者 Shenfang YUAN, Yingdi XU and Ge PENGThe Smart Materials & Structures Aeronautic Key Laboratory, Nanjing University of Aeronautic and Astronautic, Nanjing 210016, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第5期490-496,共7页
Structure health monitoring based on diagnostic Lamb waves has been found to be one of the most promising techniques recently. This paper has a brief review of the new developments on this method including the basic n... Structure health monitoring based on diagnostic Lamb waves has been found to be one of the most promising techniques recently. This paper has a brief review of the new developments on this method including the basic novel of the method, fundamentals and mathematics of Lamb wave propagation, narrowband and wideband Lamb wave excitation methods, optimization of excitation factors and diagnostic Lamb wave interpretation methods. 展开更多
关键词 Structural health monitoring Lamb wave methods factor optimization Damage localization
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Experimental investigation on the optical remote sensing images of internal solitary waves with a smooth surface 被引量:2
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作者 Yuan Mei Jing Wang +2 位作者 Songsong Huang Haidi Mu Xu Chen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第6期124-131,共8页
The parameter inversion of internal solitary waves (ISWs) based on optical remote sensing images is a key work. A new approach is proposed and demonstrated for simulating the optical remote sensing images of ISWs with... The parameter inversion of internal solitary waves (ISWs) based on optical remote sensing images is a key work. A new approach is proposed and demonstrated for simulating the optical remote sensing images of ISWs with a smooth surface in the laboratory. An optical remote sensing simulation system used to detect ISWs is constructed by a two-dimensional ISW flume, a LED (light emitting diode) light source and two CCD (charge coupled device) cameras. The optical remote sensing images of the horizontal surface and ISWs propagation images of a vertical side are detected simultaneously, which aims to explore the response of optical remote sensing corresponding to ISWs with the smooth surface. The results show that during the propagation of ISWs, dark pattern images are obtained by CCD 1 camera. The characteristics of the dark patterns vary along with the incident angle of the light source. The characteristic parameters of the optical remote sensing images correspond to the wave factors of vertical profiles. The experiment also shows a positive correlation between the dark pattern width and the half wave width under different amplitudes of ISWs. The system has the advantages of clear phenomenon and high repeatability, which provides the scientific basis for quantitative investigation on imaging mechanism of ISW by optical remote sensing. 展开更多
关键词 internal SOLITARY wave optical REMOTE sensing image DARK pattern HALF wave WIDTH wave factors
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Groupiness of Sea Waves and Their Characteristic Parameters 被引量:3
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作者 Yu Yuxiu Gui Manhai Professor, Dept. of Civil Eng. Dalian University of Technology, Dalian 116024 Master, Dept. of Civil Eng. Dalian University of Technology, Dalian 116024 《China Ocean Engineering》 SCIE EI 1996年第1期85-98,共14页
Three methods for studying wave groups and their main parameters for describing wave groupiness are reviewed in this paper. Then they are analyzed and compared combined with field data from both aspects of group heigh... Three methods for studying wave groups and their main parameters for describing wave groupiness are reviewed in this paper. Then they are analyzed and compared combined with field data from both aspects of group height and group length. A method and two parameters that can describe wave groupiness are suggested. The groupiness parameters of sea waves at three field stations are given. The effects of groupiness on both distributions of the wave height and the phase of component waves are investigated. The effects of datum length on the calculated value of grouping parameters are also discussed. 展开更多
关键词 wave group groupiness factor group height parameter wave envelope
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Assessment of seismic amplification factor of excavation with support system 被引量:3
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作者 Hamidreza Tavakoli Saman Soleimani Kutanaei Seyed Hossein Hosseini 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2019年第3期555-566,共12页
Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of th... Retaining walls have been used in many construction projects such as for road and inclined surfaces protection. The damage caused by an earthquake depends on the fundamental frequency, amplitude and the duration of the seismic motion. These parameters strongly depend on the seismic properties of the layers that are near the surface. In the study of retaining walls, in addition to the infl uence of soil, the infl uence of topography is also important. In the present study, site response analysis is performed by using fi nite element software PLAXIS to obtain the eff ect of various factors such as embedded length of the sheet pile, underground water table, length and angle of the nail, shear wave velocity of soil on site eff ect and dynamic response. Moreover, for better understanding of the eff ect of the above parameters, the stability analysis was performed by using shear reduction method. The results show that an increase in the embedded length of the sheet pile and the length of nailing causes an increase in the amplifi cation factor. Moreover, for shear-wave velocity in the range of 200- 600 m/s, the amplifi cation factor increases with increase of the shear-wave velocity due to the decrease of nonlinear behavior. 展开更多
关键词 amplifi CATION factor safety factor shear wave velocity NAILING sheet PILE
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Stability condition of finite difference solution for viscoelastic wave equations 被引量:1
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作者 Chengyu Sun Yunfei Xiao +1 位作者 Xingyao Yin Hongchao Peng 《Earthquake Science》 CSCD 2009年第5期479-485,共7页
The stability problem is a very important aspect in seismic wave numerical modeling. Based on the theory of seismic waves and constitutive equations of viscoelastic models, the stability problems of finite difference ... The stability problem is a very important aspect in seismic wave numerical modeling. Based on the theory of seismic waves and constitutive equations of viscoelastic models, the stability problems of finite difference scheme for Kelvin- Voigt and Maxwell models with rectangular grids are analyzed. Expressions of stability conditions with arbitrary spatial accuracies for two viscoelastic models are derived. With approximation of quality factor Q≥5, simplified expressions are developed and some numerical models are given to verify the validity of the corresponding theoretical results. Then this paper summarizes the influences of seismic wave velocity, frequency, size of grid and difference coefficients, as well as quality factor on stability condition. Finally the prerequisite conditions of the simplified stability equations are given with error analysis. 展开更多
关键词 finite difference STABILITY viscoelastic model wave equation quality factor
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S wave inelastic attenuation and site effect in the northern Tianshan area
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作者 姜慧 高孟潭 +1 位作者 俞言祥 唐丽华 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第2期188-193,共6页
In this paper, according to the relationship of observation spectrum with source spectrum, travel-path attenuation factor and site effect, we use the digital seismic data of moderate-small earthquakes to invert the so... In this paper, according to the relationship of observation spectrum with source spectrum, travel-path attenuation factor and site effect, we use the digital seismic data of moderate-small earthquakes to invert the soft rock site effect and S wave inelastic attenuation under the constraint of site effect, and determine the parameters of path and site. The parameters obtained by this method exclude the topographic effect of seismic stations, and truly reflect the seismic effect of free soft rock sites and the S wave inelastic attenuation in the studied region. The average soft rock site effect is about 1.5 times in the frequency domain of 2-4 Hz and the S wave quality factor is obtained as Qs=278f0.346, which can be directly applied to the stochastic modeling of ground motions in the studied region. 展开更多
关键词 S wave quality factor site effect inelastic attenuation northern Tianshan area
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A Simple Eddy Viscosity Model of Rough Turbulent Wave Boundary Layer
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作者 Hsu Tai-Wen and Lin Hwung-Yui Associate Professor, Department of Hydraulics and Ocean Engineering, National Cheng Kung University, Tainan Graduate student, Department of Hydraulics and Ocean Engineering, National Cheng Kung University, Tainan 《China Ocean Engineering》 SCIE EI 1996年第3期281-294,共14页
A one-layer time-invariant eddy viscosity model is specified to develop a mathematical model for describing the essential features of the turbulent wave boundary layer over a rough bed. The functional form of the eddy... A one-layer time-invariant eddy viscosity model is specified to develop a mathematical model for describing the essential features of the turbulent wave boundary layer over a rough bed. The functional form of the eddy viscosity is evaluated based on computational results from a two-equation turbulence model in which the eddy viscosity varies with time and space. The present eddy viscosity model simplifies much of the mathematical complexity in many existing models. Predictions from the present model have been compared with a wide range of experimental data. It is found that the eddy viscosity model adopted in the present study is physically reasonable. 展开更多
关键词 turbulent wave boundary layer eddy viscosity wave fiction factor
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