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Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation
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作者 Ruibo Li Jin-Long Jiao +3 位作者 Hui Luo Dezhi Zhang Dengwang Wang Kai Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期53-69,共17页
Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significan... Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant concern.The blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray irradiation.However,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex configurations.In this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray irradiation.This significantly reduces the dependence of the numerical simulation on the grid shape.The reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results. 展开更多
关键词 X-ray irradiation Energy deposition Blow-off impulse Particle in cells
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Force and impulse multi-sensor based on flexible gate dielectric field effect transistor
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作者 Chao Tan Junling Lü +3 位作者 Chunchi Zhang Dong Liang Lei Yang Zegao Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期214-220,共7页
Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive ... Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate response.However,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of time.Herein we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor application.We systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 nW.The sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on it.Moreover,there was almost no performance loss for the device as left in the air for two months. 展开更多
关键词 flexible gate dielectric transistor force sensor impulse sensor force sensor array
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Dynamic propagation velocity of a positive streamer in a 3 m air gap under lightning impulse voltage
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作者 李志伟 雷挺 +5 位作者 苏宇 姚修远 杨冰雪 刘德龙 律方成 丁玉剑 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期114-121,共8页
Streamers represent an important stage in the initiation of gap discharge. In this work, we used an eight-frame intensified charge-coupled device camera to capture the streamer development process when a lightning imp... Streamers represent an important stage in the initiation of gap discharge. In this work, we used an eight-frame intensified charge-coupled device camera to capture the streamer development process when a lightning impulse voltage of 95%–100% U50% was applied in a 3 m rod–plate gap and the streamer velocity was analyzed. Analysis of the observations shows that streamer velocity can be defined by three stages: rapid velocity decline(stage 1), rapid velocity rise(stage 2)and slow velocity decline(stage 3). The effects of electrode shape, applied voltage and gap breakdown or withstanding on streamer velocity were analyzed. The electrode with a larger radius of curvature will result in a higher initial velocity, and a higher voltage amplitude will cause the streamer to propagate faster at stage 3. Gap withstanding or breakdown has no obvious effect on streamer velocity. In addition, the experimental results are compared with previous results and the statistical characteristics of the primary streamer discharge are discussed. 展开更多
关键词 lightning impulse 3 m air gap development process streamer velocity
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ON DE FINETTI'S OPTIMAL IMPULSE DIVIDEND CONTROL PROBLEM UNDER CHAPTER 11 BANKRUPTCY
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作者 王文元 明瑞星 胡亦钧 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期215-233,共19页
Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow[44]to revisit the De Finetti dividend control problem under the... Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow[44]to revisit the De Finetti dividend control problem under the reorganization process and the regulator's intervention documented in U.S.Chapter 11 bankruptcy.We do this by further accommodating the fixed transaction costs on dividends to imitate the real-world procedure of dividend payments.Incorporating the fixed transaction costs transforms the targeting optimal dividend problem into an impulse control problem rather than a singular control problem,and hence computations and proofs that are distinct from[44]are needed.To account for the financial stress that is due to the more subtle concept of Chapter 11 bankruptcy,the surplus process after dividends is driven by a piece-wise spectrally negative Lévy process with endogenous regime switching.Some explicit expressions of the expected net present values under a double barrier dividend strategy,new to the literature,are established in terms of scale functions.With the help of these expressions,we are able to characterize the optimal strategy among the set of admissible double barrier dividend strategies.When the tail of the Lévy measure is log-convex,this optimal double barrier dividend strategy is then verified as the optimal dividend strategy,solving our optimal impulse control problem. 展开更多
关键词 spectrally negative Lévy process Chapter 11 bankruptcy De Finetti's dividend problem double barrier strategy impulse control
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Direction finding of bistatic MIMO radar in strong impulse noise
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作者 CHEN Menghan GAO Hongyuan +2 位作者 DU Yanan CHENG Jianhua ZHANG Yuze 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期888-898,共11页
For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in ... For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in suppressing impulse noise and achieving superior direction finding performance using the maximum likelihood(ML)estimation method.A quantum equilibrium optimizer algorithm(QEOA)is devised to resolve the corresponding objective function for efficient and accurate direc-tion finding.The results of simulation reveal the capability of the presented method in success rate and root mean square error over existing direction-finding methods in different application situations,e.g.,locating coherent signal sources with very few snapshots in strong impulse noise.Other than that,the Cramér-Rao bound(CRB)under impulse noise environment has been drawn to test the capability of the presented method. 展开更多
关键词 bistatic multiple-input multiple-output(MIMO)radar impulse noise direction finding lower order covariance quan-tum equilibrium optimizer algorithm(QEOA) maximum likeli-hood estimation method Cramér-Rao bound(CRB)
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基于Impulse 7000DP对除颤监护仪的质控方法研究
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作者 孟雪圻 辛红 王鹏发 《产品可靠性报告》 2024年第6期63-64,共2页
除颤监护仪是用于临床抢救的医疗设备,凭借其疗效确切、作用快、操作简便等优势,广泛应用于各级医疗单位中。该仪器是临床上经常使用的高风险医疗设备,其释放能量的准确性直接影响到其救治效果,因此必须定期进行检测。本文按照JJF 1149... 除颤监护仪是用于临床抢救的医疗设备,凭借其疗效确切、作用快、操作简便等优势,广泛应用于各级医疗单位中。该仪器是临床上经常使用的高风险医疗设备,其释放能量的准确性直接影响到其救治效果,因此必须定期进行检测。本文按照JJF 1149—2014《心脏除颤器校准规范》中针对除颤监护仪的校准方法,使用除颤器/经皮起搏器分析仪Impulse 7000DP对除颤监护仪的质控方法展开研究。 展开更多
关键词 除颤监护仪 除颤器/经皮起搏器分析仪 impulse 7000DP 校准
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Saccades of video head impulse test in Meniere's disease and Vestibular Migraine: What can we learn from? 被引量:2
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作者 Yi Du Xingjian Liu +4 位作者 Lili Ren Yu Wang Fei Ji Weiwei Guo Ziming Wu 《Journal of Otology》 CSCD 2023年第2期79-84,共6页
Background:Saccades are often observed on video head impulse tests(vHIT)in patients with Meniere's Disease(MD)and Vestibular Migraine(VM).However,their saccadic features are not fully described.Objective:This stud... Background:Saccades are often observed on video head impulse tests(vHIT)in patients with Meniere's Disease(MD)and Vestibular Migraine(VM).However,their saccadic features are not fully described.Objective:This study aims to identify the saccades characteristics of MD and VM.Methods:75 VM patients and 103 definite unilateral MD patients were enrolled in this study.First raw saccades were exported and analyzed.The VM patients were divided into left and right based on their ears,while the MD patients were separated into affected and unaffected subgroups based on their audiograms and symptoms.Results:The MD patients have more saccades on the affected side(85%vs.69%),and saccade velocity is more consistent than the contralateral side(shown by the coefficient of variation).The saccades occurrence rates on both sides are similar in VM(77%vs.76%),as are other saccadic parameters.The MD patients have more significant inter-aural differences than the VM patients,manifested in higher velocity(p-value 0.000),earlier arriving(p-value 0.010),and more time-domain gathered(p-value 0.003)on the affected side.Conclusions:Bilateral saccades are commonly observed in MD and VM.In contrast to MD,saccades on VM are subtle,scattered,and late-arrived.Furthermore,the MD patients showed inconsistent saccadic distribution with more velocity-uniform saccades on the affected side. 展开更多
关键词 Meniere's disease Vestibular migraine SACCADES Video head impulse test Differential diagnosis
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Acoustic radiation force impulse predicts long-term outcomes in a large-scale cohort:High liver cancer,low comorbidity in hepatitis B virus 被引量:1
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作者 Jennifer Tai Adam P Harrison +7 位作者 Hui-Ming Chen Chiu-Yi Hsu Tse-Hwa Hsu Cheng-Jen Chen Wen-Juei Jeng Ming-Ling Chang Le Lu Dar-In Tai 《World Journal of Gastroenterology》 SCIE CAS 2023年第14期2188-2201,共14页
BACKGROUND Acoustic radiation force impulse(ARFI)is used to measure liver fibrosis and predict outcomes.The performance of elastography in assessment of fibrosis is poorer in hepatitis B virus(HBV)than in other etiolo... BACKGROUND Acoustic radiation force impulse(ARFI)is used to measure liver fibrosis and predict outcomes.The performance of elastography in assessment of fibrosis is poorer in hepatitis B virus(HBV)than in other etiologies of chronic liver disease.AIM To evaluate the performance of ARFI in long-term outcome prediction among different etiologies of chronic liver disease.METHODS Consecutive patients who received an ARFI study between 2011 and 2018 were enrolled.After excluding dual infection,alcoholism,autoimmune hepatitis,and others with incomplete data,this retrospective cohort were divided into hepatitis B(HBV,n=1064),hepatitis C(HCV,n=507),and non-HBV,non-HCV(NBNC,n=391)groups.The indexed cases were linked to cancer registration(1987-2020)and national mortality databases.The differences in morbidity and mortality among the groups were analyzed.RESULTS At the enrollment,the HBV group showed more males(77.5%),a higher prevalence of prediagnosed hepatocellular carcinoma(HCC),and a lower prevalence of comorbidities than the other groups(P<0.001).The HCV group was older and had a lower platelet count and higher ARFI score than the other groups(P<0.001).The NBNC group showed a higher body mass index and platelet count,a higher prevalence of pre-diagnosed non-HCC cancers(P<0.001),especially breast cancer,and a lower prevalence of cirrhosis.Male gender,ARFI score,and HBV were independent predictors of HCC.The 5-year risk of HCC was 5.9%and 9.8%for those ARFI-graded with severe fibrosis and cirrhosis.ARFI alone had an area under the receiver operating characteristic curve(AUROC)of 0.742 for prediction of HCC in 5 years.AUROC increased to 0.828 after adding etiology,gender,age,and platelet score.No difference was found in mortality rate among the groups.CONCLUSION The HBV group showed a higher prevalence of HCC but lower comorbidity that made mortality similar among the groups.Those patients with ARFI-graded severe fibrosis or cirrhosis should receive regular surveillance. 展开更多
关键词 Non-alcoholic fatty liver disease Hepatitis B Hepatocellular carcinoma Acoustic radiation force impulse MORTALITY COMORBIDITY
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Method of SLAS’s ground track manipulation based on tangential impulse thrust
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作者 LE Xinlong CAO Xibin +1 位作者 DAI Yu WU Fan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第5期1285-1293,共9页
Satellites with altitudes below 400 km are called super low altitude satellites(SLAS),often used to achieve responsive imaging tasks.Therefore,it is important for the manipulation of its ground track.Aiming at the pro... Satellites with altitudes below 400 km are called super low altitude satellites(SLAS),often used to achieve responsive imaging tasks.Therefore,it is important for the manipulation of its ground track.Aiming at the problem of ground track manipulation of SLAS,a control method based on tangential impulse thrust is proposed.First,the equation of the longitude difference between SLAS and the target point on the target latitude is derived based on Gauss’s variational equations.On this basis,the influence of the tangential impulse thrust on the ground track’s longitude is derived.Finally,the method for ground track manipulation of SLAS under the tangential impulse thrust is proposed.The simulation results verify the effective-ness of the method,after manipulation,the satellite can visit the target point and revisit it for multiple days. 展开更多
关键词 super low altitude satellite(SLAS) ground track drift modeling ground track manipulation tangential impulse thrust
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Proper Understanding of the Nerve Impulses and the Action Potential
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作者 Salama Abdelhady 《World Journal of Neuroscience》 2023年第3期103-117,共15页
Neurologists define the transmission of nerve impulses across the membranes of the neural cells as a result of difference in the concentration of ions while they measured an electric potential, called as an action pot... Neurologists define the transmission of nerve impulses across the membranes of the neural cells as a result of difference in the concentration of ions while they measured an electric potential, called as an action potential, which allows the propagation of such nerve impulses as electrical signals. Such measurements should guide them to a logical explanation of the nerve impulses as electric charges driven by the measured action potential. However, such logical conclusion, or explanation, is ignored due to a wrong definition of the flow of electric charges as a flow of electrons that cannot pass through neural networks. According to recent studies, electric charges are properly defined as electromagnetic (EM) waves whose energy is expressed as the product of its propagating electric potential times their entropy flow which is adhered to the flow of such energy. Such definition matches the logical conclusion of the nerve impulses as electric charges, as previously explained, and defines the entropy of the neural network, measured by Ammeters, in Watt or Joule/Volt. The measured entropy represents a neurodiagnostic property of the neural networks that measures its capacity to allow the flow of energy per unit action potential. Theoretical verification of the innovative definition of nerve impulses is presented by following an advanced entropy approach. A proper review of the machine records of the stimulating electric charges, used in the diagnosis of the neural networks, and the stimulated nerve impulses or stimulated responses, represents practical verifications of the innovative definitions of the electric charges and the nerve impulses. Comparing the functioning of the thermoelectric generators and the brain neurons, such neurons are defined as thermoelectric generators of the electric nerve impulses and their propagating, or action, potential. 展开更多
关键词 Nerve impulses Action Potential Electric Charges ENTROPY Electromagnetic Waves Thermoelectric Generators
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Research on the Relationship Between Environmental and Economic Coupling Systems in Bohai Bay Area Based on a Vector Autoregression(VAR)Model 被引量:1
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作者 CAO Huimin WANG Ping +2 位作者 ZHANG Surong XU Dongpo TIAN Weijun 《Journal of Ocean University of China》 CAS CSCD 2024年第2期557-566,共10页
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(V... This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration. 展开更多
关键词 Bohai Bay area environmental pollution industrial structure cointegration theory VAR model impulse response
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基于IMPULSE C的GF(P)域椭圆加密算法的硬件加速 被引量:2
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作者 崔强强 金同标 朱勇 《计算机应用》 CSCD 北大核心 2011年第9期2385-2388,共4页
研究了大素数域上的椭圆曲线加密算法,基于IMPULSE C语言,对该算法进行编程实现;在标准射影坐标系下,对点加和倍加算法进行并行化改进,并且在编程时利用编译器特性做了进一步的并行化。通过对加密算法合理的软硬件分割,将计算量大而且... 研究了大素数域上的椭圆曲线加密算法,基于IMPULSE C语言,对该算法进行编程实现;在标准射影坐标系下,对点加和倍加算法进行并行化改进,并且在编程时利用编译器特性做了进一步的并行化。通过对加密算法合理的软硬件分割,将计算量大而且复杂的点乘运算作为硬件部分,通过现场可编程门陈列(FPGA)进行硬件加速;将加密协议的其他部分作为软件部分,在传统CPU上执行,并将硬件部分生成VHDL代码。分别进行加密算法的CoDeveloper的桌面仿真和生成的硬件VHDL代码的ISE综合仿真。最后将该加速设计在Xilinx Virtex-5 xc5vfx70tFPGA开发板上作了实现,基于FPGA的实验结果表明,P-192上点乘运算处理在133 MHz时钟下用时2.9 ms,硬件资源分配合理,与现有的手工编写的HDL代码相比,具有并行加速优势。 展开更多
关键词 椭圆曲线密码学 素数域 射影坐标系 impulse C 现场可编程门陈列
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基于Impulse C的AES加密算法的仿真与实现 被引量:1
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作者 严利民 李建东 《计算机技术与发展》 2012年第10期184-187,共4页
加解密算法在信息安全领域受到了越来越广泛的关注。文中介绍了一种利用Impulse C语言对AES加密算法进行编程的方法,并在软硬件协同设计平台上对应用程序进行了桌面仿真。通过对Application Monitor的调用,对进程间数据进行监控,有效提... 加解密算法在信息安全领域受到了越来越广泛的关注。文中介绍了一种利用Impulse C语言对AES加密算法进行编程的方法,并在软硬件协同设计平台上对应用程序进行了桌面仿真。通过对Application Monitor的调用,对进程间数据进行监控,有效提高了仿真调试的效率。最后,将应用程序转换成为Verilog代码,手工编写了测试代码,并在Modelsim中进行了RTL级仿真,得到了正确的仿真结果。文中建立了算法描述语言到硬件描述语言的翻译,对于缩短设计周期具有一定意义。 展开更多
关键词 信息安全 AES算法 impulse C Application MONITOR 硬件描述语言
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Analysis and Design of Time-Delay Impulsive Systems Subject to Actuator Saturation
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作者 Chenhong Zhu Xiuping Han Xiaodi Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期196-204,共9页
This paper investigates the exponential stability and performance analysis of nonlinear time-delay impulsive systems subject to actuator saturation. When continuous dynamics is unstable, under some conditions, it is s... This paper investigates the exponential stability and performance analysis of nonlinear time-delay impulsive systems subject to actuator saturation. When continuous dynamics is unstable, under some conditions, it is shown that the system can be stabilized by a class of saturated delayed-impulses regardless of the length of input delays. Conversely, when the system is originally stable, it is shown that under some conditions, the system is robust with respect to sufficient small delayed-impulses. Moreover, the design problem of the controller with the goal of obtaining a maximized estimate of the domain of attraction is formulated via a convex optimization problem. Three examples are provided to demonstrate the validity of the main results. 展开更多
关键词 Delayed impulses impulsive control impulsive disturbance nonlinear systems SATURATION
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Maximum initial primary wave model for low-Froude-number reservoir landslides based on wave theory
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作者 LI Yang HUANG Bolin +2 位作者 QIN Zhen DONG Xingchen HU Lei 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2664-2680,共17页
The impulse waves induced by large-reservoir landslides can be characterized by a low Froude number.However,systematic research on predictive models specifically targeting the initial primary wave is lacking.Taking th... The impulse waves induced by large-reservoir landslides can be characterized by a low Froude number.However,systematic research on predictive models specifically targeting the initial primary wave is lacking.Taking the Shuipingzi 1#landslide that occurred in the Baihetan Reservoir area of the Jinsha River in China as an engineering example,this study established a large-scale physical model(with dimensions of 30 m×29 m×3.5 m at a scale of 1:150)and conducted scaled experiments on 3D landslide-induced impulse waves.During the process in which a sliding mass displaced and compressed a body of water to generate waves,the maximum initial wave amplitude was found to be positively correlated with the sliding velocity and the volume of the landslide.With the increase in the water depth,the wave amplitude initially increased and then decreased.The duration of pressure exertion by the sliding mass at its maximum velocity directly correlated with an elevated wave amplitude.Based on the theories of low-amplitude waves and energy conservation,while considering the energy conversion efficiency,a predictive model for the initial wave amplitude was derived.This model could fit and validate the functions of wavelength and wave velocity.The accuracy of the initial wave amplitude was verified using physical experiment data,with a prediction accuracy for the maximum initial wave amplitude reaching 90%.The conversion efficiency(η)directly determined the accuracy of the estimation formula.Under clear conditions for landslide-induced impulse wave generation,estimating the value ofηthrough analogy cases was feasible.This study has derived the landslide-induced impulse waves amplitude prediction formula from the standpoints of wave theory and energy conservation,with greater consideration given to the intrinsic characteristics in the formation process of landslide-induced impulse waves,thereby enhancing the applicability and extensibility of the formula.This can facilitate the development of empirical estimation methods for landslide-induced impulse waves toward universality. 展开更多
关键词 Three-dimensional physical model experiments Reservoir-landslide-induced impulse wave Energy conversion efficiency Landslide-induced impulse wave prediction model Shuipingzi 1#landslide
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PCA-LSTM:An Impulsive Ground-Shaking Identification Method Based on Combined Deep Learning
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作者 Yizhao Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3029-3045,共17页
Near-fault impulsive ground-shaking is highly destructive to engineering structures,so its accurate identification ground-shaking is a top priority in the engineering field.However,due to the lack of a comprehensive c... Near-fault impulsive ground-shaking is highly destructive to engineering structures,so its accurate identification ground-shaking is a top priority in the engineering field.However,due to the lack of a comprehensive consideration of the ground-shaking characteristics in traditional methods,the generalization and accuracy of the identification process are low.To address these problems,an impulsive ground-shaking identification method combined with deep learning named PCA-LSTM is proposed.Firstly,ground-shaking characteristics were analyzed and groundshaking the data was annotated using Baker’smethod.Secondly,the Principal Component Analysis(PCA)method was used to extract the most relevant features related to impulsive ground-shaking.Thirdly,a Long Short-Term Memory network(LSTM)was constructed,and the extracted features were used as the input for training.Finally,the identification results for the Artificial Neural Network(ANN),Convolutional Neural Network(CNN),LSTM,and PCA-LSTMmodels were compared and analyzed.The experimental results showed that the proposed method improved the accuracy of pulsed ground-shaking identification by>8.358%and identification speed by>26.168%,compared to other benchmark models ground-shaking. 展开更多
关键词 Impulsive ground-shaking principal component analysis artificial intelligence deep learning impulse recognition
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Experimental and numerical investigation on alternatives to sandy gravel
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作者 V.Denefeld H.Aurich 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期130-141,共12页
The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle.The Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbe... The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle.The Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbelly improvised explosive device(IEDs),which must be buried in water-saturated sandy gravel.The use of sandy gravel has some drawbacks,for instance reproducibility,time consumption,and cost.This paper focuses on the investigation of four alternatives to sandy gravel,which could produce similar specific and cumulative impulses:a concrete pot filled with water,a concrete pot filled with quartz sand,a steel pot without filling and a concrete pot filled with glass spheres(diameter 200μm—300μm)and different water contents.The impulses are measured with a ring technology developed at the Fraunhofer EMI.A numerical soil model based on the work of Marrs,2014 and Fi serov a,2006 and considering the soil moisture was used to simulate the experiments with glass spheres at different water contents,showing much better agreement with the experiments than the classical Laine&Sandvik model,even for high saturation levels.These results can be used to create new test conditions at original scale that are more cost-effective,more reproducible and simpler to manage in comparison to the current tests carried out with STANAG sandy gravel. 展开更多
关键词 Improvised explosive device(IED) Specific impulse Momentum transfer Sandy gravel Glass spheres Numerical model Soil moisture
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Application of ultrasonography-elastography score to suspect porto-sinusoidal vascular disease in patients with portal vein thrombosis
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作者 Stefania Gioia Adriano De Santis +5 位作者 Giulia d’Amati Silvia Nardelli Alessandra Spagnoli Arianna Di Rocco Lorenzo Ridola Oliviero Riggio 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2024年第1期20-24,共5页
Background:Porto-sinusoidal vascular disease(PSVD)and portal vein thrombosis(PVT)are causes of portal hypertension characterized respectively by an intrahepatic and a pre-hepatic obstacle to the flow in the portal sys... Background:Porto-sinusoidal vascular disease(PSVD)and portal vein thrombosis(PVT)are causes of portal hypertension characterized respectively by an intrahepatic and a pre-hepatic obstacle to the flow in the portal system.As PVT may be a consequence of PSVD,in PVT patients at presentation,a pre-existing PSVD should be suspected.In these patients the identification of an underlying PSVD would have relevant implication regarding follow-up and therapeutic management,but it could be challenging.In this setting ultrasonography may be valuable in differential diagnosis.The aim of the study was to use ultrasonography to identify parameters to discriminate between PSVD and“pure”PVT and then to suspect PVT secondary to a pre-existing PSVD.Methods:Fifty-three patients with histologically proven PSVD and forty-eight patients affected by chronic PVT were enrolled and submitted to abdominal ultrasonography with elastography by acoustic radiation force impulse(ARFI).Results:ARFI was higher and superior mesenteric vein(SMV)diameter was wider in PSVD patients than in PVT patients.Thus,a prognostic score was obtained as linear combinations of the two parameters with a good discrimination capacity between PSVD and PVT(the area under the curve=0.780;95%confidence interval:0.690-0.869).Conclusions:A score based on ARFI and SMV diameter may be useful to suspect an underlying PSVD in patients with PVT and to identify a subgroup of patients to be submitted to liver biopsy. 展开更多
关键词 Non-cirrhotic portal hypertension Porto-sinusoidal vascular disease Chronic portal vein thrombosis Liver stiffness Portal hypertension Acoustic radiation force impulse
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基于Impulse C的软硬件协同设计及应用 被引量:1
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作者 姚大勇 杨广文 卢琳 《辽宁工学院学报》 2007年第3期152-155,159,共5页
介绍了Impulse Accelerated Technologies公司推出的CoDeveloper硬件/软件协同开发工具,结合实例说明如何基于Impulse C库函数在CoDeveloper工具及Xilinx公司的EDK嵌入式开发环境下进行软硬件协同开发的新技术,为软、硬件工程师特别是... 介绍了Impulse Accelerated Technologies公司推出的CoDeveloper硬件/软件协同开发工具,结合实例说明如何基于Impulse C库函数在CoDeveloper工具及Xilinx公司的EDK嵌入式开发环境下进行软硬件协同开发的新技术,为软、硬件工程师特别是软件工程师开发基于FPGA的嵌入式系统提供了新的思路。 展开更多
关键词 impulse C CoDeveloper FPGA 协同设计
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Modeling Near-Field Impulsive Waves Generated by Deformable Landslide Using the HBP Model Based on the SPH Method
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作者 WANG Wei WEI Weicheng +4 位作者 CHAI Bo XIA Hao WANG Yang DU Juan LIU Jizhixian 《Journal of Ocean University of China》 CAS CSCD 2024年第2期328-344,共17页
Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side slopes.The risk reduction and mitigation of such a hazard re... Landslide-generated impulsive waves(LGWs)in reservoir areas can seriously threaten waterway safety as well as hu-man life and properties around the two side slopes.The risk reduction and mitigation of such a hazard require the accurate prediction of near-field wave characteristics,such as wave amplitude and run-up.However,near-field LGW involves complicated fluid-solid interactions.Furthermore,the wave characteristics are closely related to various aspects,including the geometry and physical features of the slide,river,and body of water.However,the empirical or analytical methods used for rough estimation cannot derive accurate results,especially for deformable landslides,due to their significant geometry changes during the sliding process.In this study,the near-field waves generated by deformable landslides were simulated by smoothed particle hydrodynamics(SPH)based on multi-phase flow.The deformable landslides were generalized as a kind of viscous flow by adopting the Herschel-Bulkley-Papanastasiou(HBP)-based nonNewtonian rheology model.The HBP model is capable of producing deformable landslide dynamics even though the high-speed sliding process is involved.In this study,an idealized experiment case originating from Lituya LGW and a practical case of Gongjiafang LGW were reproduced for verification and demonstration.The simulation results of both cases show satisfactory consistency with the experiment/investigation data in terms of landslide movement and near-field impulsive wave characteristics,thus indicating the applicability and accuracy of the proposed method.Finally,the effects of the HBP model’s rheological parameters on the landslide dynamics and near-field wave characteristics are discussed,providing a parameter calibration method along with sug-gestions for further applications. 展开更多
关键词 deformable landslide impulsive waves NEAR-FIELD SPH nonNewtonian fluids
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