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Vertical deformation model on postseismic phase using exponential and logarithmic function based on InSAR
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作者 Irma Yusiyanti Tattyana Wening Kalbuadi Prajardi +1 位作者 Yofita Indah Saputri Cecep Pratama 《Geodesy and Geodynamics》 EI CSCD 2023年第4期392-400,共9页
The Palu MW7.4 earthquake occurred on September 28, 2018, with the epicenter at 119.86°, 0.72°. The severe shaking caused severe damage in Central Sulawesi, especially in Palu. We conducted a postseismic def... The Palu MW7.4 earthquake occurred on September 28, 2018, with the epicenter at 119.86°, 0.72°. The severe shaking caused severe damage in Central Sulawesi, especially in Palu. We conducted a postseismic deformation study to determine the deformation pattern and reduce future earthquakes’ impact.Interferometric Synthetic Aperture Radar(In SAR) data were processed using Li CSBAS to get the time series. The time series data were fitted to exponential and logarithmic functions to determine the mechanism of postseismic deformation. The exponential model identified the influence of the viscoelastic mechanism, and the logarithm identified the afterslip mechanism. The Palu earthquake was fitted to logarithmic and exponential, but the logarithmic was more significant than an exponential function.Afterslip mechanism predominates, and viscoelastic mechanisms play a minor role in this postseismic deformation. 展开更多
关键词 EARTHQUAKE DEFORMATION POSTSEISMIC Physical mechanism exponential logarithmic
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Solutions for Series of Exponential Equations in Terms of Lambert-W Function and Fundamental Constants 被引量:1
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作者 S. Gnanarajan 《Journal of Applied Mathematics and Physics》 2018年第4期725-736,共12页
Series of exponential equations in the form of were solved graphically, numerically and analytically. The analytical solution was derived in terms of Lambert-W function. A general numerical solution for any y is found... Series of exponential equations in the form of were solved graphically, numerically and analytically. The analytical solution was derived in terms of Lambert-W function. A general numerical solution for any y is found in terms of n or in base y. A solution is close to the fine structure constant. The equation which provided the solution as the fine structure constant was derived in terms of the fundamental constants. 展开更多
关键词 exponential EQUATION Lambert-W FUNCTION Fine Structure Constant logarithmic EQUATION Numerical Analysis FUNDAMENTAL CONSTANTS
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Design and Simulation of Solid State Pulser with Fast Rise Time and Double-exponential Waveform 被引量:3
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作者 YANG Qingxi WANG Qingguo +2 位作者 ZHOU Xing ZHAO Min ZHANG Yongqiang 《高电压技术》 EI CAS CSCD 北大核心 2014年第1期237-241,共5页
Voltage pulses with fast rise time can be obtained from Marx circuits based on avalanche transistors. In this research, the ZETEX avalanche transistors are used as the switches in a Marx circuit to generate stable vol... Voltage pulses with fast rise time can be obtained from Marx circuits based on avalanche transistors. In this research, the ZETEX avalanche transistors are used as the switches in a Marx circuit to generate stable voltage pulses with double-exponential waveform and fast rise time. By using these transistors, the circuit is able to generate higher pulsed voltage with fewer stages. A three stages and a ten stages Marx circuit, as well as their triggering circuits, are designed. The two Marx circuits are also tested by simulations based on the Pspice code and by experiments, results of which are consistent with each other. With the ten stages Marx circuit, we obtain positive and negative pulses with the rise time of about 1.5 ns, the amplitude above 1 100 V, and the pulse width below 5 ns. It is proved that the proposed Marx circuit equipped with avalanche transistors could be an effective kind of solid-state pulse generator. 展开更多
关键词 脉冲发生器 电路设计 上升时间 波形 固态 雪崩晶体管 仿真 PSPICE
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对数法在幂指形函数极限中的推广与应用
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作者 杨磊 《高等数学研究》 2024年第5期16-18,共3页
本文以幂指函数为雏形进行推广,用对数法的思想,化简三种类型的“幂指形”函数,求极限方法简单,通用性强.
关键词 极限 对数法 幂指函数
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Static CMOS Implementation of Logarithmic Skip Adder
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作者 贾嵩 刘飞 +2 位作者 刘凌 陈中建 吉利久 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第11期1159-1165,共7页
Circuit design of 32 bit logarithmic skip adder (LSA) is introduced to implement high performance,low power addition.ELM carry lookahead adder is included into groups of carry skip adder and the hybrid structure cost... Circuit design of 32 bit logarithmic skip adder (LSA) is introduced to implement high performance,low power addition.ELM carry lookahead adder is included into groups of carry skip adder and the hybrid structure costs 30% less hardware than ELM.At circuit level,a carry incorporating structure to include the primary carry input in carry chain and an 'and xor' structure to implement final sum logic in 32 bit LSA are designed for better optimization.For 5V,1μm process,32 bit LSA has a critical delay of 5 9ns and costs an area of 0 62mm 2,power consumption of 23mW at 100MHz.For 2 5V,0 25μm process,critical delay of 0 8ns,power dissipation of 5 2mW at 100MHz is simulated. 展开更多
关键词 logarithmic skip carry incorporating sum logic circuit design
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吸引子共存的四维多稳态混沌系统及同步电路
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作者 杨阳 摆玉龙 +1 位作者 李艳 张庆 《现代电子技术》 北大核心 2024年第14期53-62,共10页
文中设计了一种具有多翼吸引子的四维混沌系统,通过改变系统的多组参数,观察到吸引子结构由四翼变为双翼。采用相图、Lyapunov指数谱、分岔图和复杂度等方法,验证系统的动力学特性。结果表明,通过改变系统参数和选择不同的初始值,系统... 文中设计了一种具有多翼吸引子的四维混沌系统,通过改变系统的多组参数,观察到吸引子结构由四翼变为双翼。采用相图、Lyapunov指数谱、分岔图和复杂度等方法,验证系统的动力学特性。结果表明,通过改变系统参数和选择不同的初始值,系统呈现出极性相反但结构相似的吸引子共存现象。使用Multisim仿真软件进行了电路仿真,发现数值分析和模拟仿真结果一致,验证了系统的可实现性。最后,采用线性反馈同步法对该系统进行了同步控制,并成功实现了同步电路仿真。所设计系统具有丰富的多稳态特性,主从系统在极短的时间内达到了同步,同步效果良好,可广泛应用于保密通信领域。 展开更多
关键词 四维混沌系统 多翼吸引子 多稳态性 LYAPUNOV指数谱 同步控制 电路仿真
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高中数学教材“指数函数与对数函数”内容的比较研究——以人教A版、苏教版和北师大版为例
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作者 张俊丽 梁亚亚 赵本银 《辽宁师专学报(自然科学版)》 2024年第2期13-19,共7页
为了让教师更好地选择和整合教学内容,从知识编排、信息技术应用2个维度对人教A版、苏教版和北师大版高中数学教材“指数函数与对数函数”内容进行比较分析.结果表明:在章节位置上,该内容均在必修第一册,但章主题各不相同,而且苏教版将... 为了让教师更好地选择和整合教学内容,从知识编排、信息技术应用2个维度对人教A版、苏教版和北师大版高中数学教材“指数函数与对数函数”内容进行比较分析.结果表明:在章节位置上,该内容均在必修第一册,但章主题各不相同,而且苏教版将此内容编排在2个章节,人教A版和北师大版则编排在同一章节;在知识含量上,苏教版多了指数函数与对数函数图象的变换,人教A版和苏教版都有函数的应用,人教A版和北师大版都有不同函数增长的差异,不同的知识编排顺序体现了不同的侧重点;在信息技术应用上,人教A版更重视信息技术的应用,北师大版则应用较少,苏教版应用要求更高.基于此,给出建议:分析课程标准和不同版本教材,选择合适的教学内容;注重知识的逻辑顺序,构建完整的知识体系. 展开更多
关键词 指数函数 对数函数 内容编排 信息技术
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一种新型四维三参数混沌指数系统及其电路实现
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作者 张玲梅 高卫华 《青海师范大学学报(自然科学版)》 2024年第1期40-45,共6页
本文研究了一种新的四维三参数混沌指数系统及其电路实现.首先,通过理论分析和数值仿真,研究该系统的基本动力学行为,如系统不变性和耗散性、平衡点稳定性、Lyapunov指数谱和分岔图等性质,结果表明该系统具有丰富的动力学特性.其次,利用... 本文研究了一种新的四维三参数混沌指数系统及其电路实现.首先,通过理论分析和数值仿真,研究该系统的基本动力学行为,如系统不变性和耗散性、平衡点稳定性、Lyapunov指数谱和分岔图等性质,结果表明该系统具有丰富的动力学特性.其次,利用Simulink软件进行电路仿真,仿真结果与数值分析结果一致,从而验证了新四维混沌系统电路实现的可行性,为指数混沌系统应用于电路设计提供了实验基础. 展开更多
关键词 混沌指数系统 三参数 动态行为 电路实现
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Beach Profiles Characteristics Along Giao Thuy and Hai Hau Coasts,Vietnam:A Field Study 被引量:2
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作者 NGUYEN Viet Thanh 郑金海 张弛 《China Ocean Engineering》 SCIE EI 2012年第4期699-712,共14页
Giao Thuy and Hai Hau coasts are located in Nam Dinh province, Vietnam, with a total coastline of 54.42 km in length. The sea-dike system has been seriously damaged and there have been many dike breaches which caused ... Giao Thuy and Hai Hau coasts are located in Nam Dinh province, Vietnam, with a total coastline of 54.42 km in length. The sea-dike system has been seriously damaged and there have been many dike breaches which caused floods and losses. This situation is considered of a general representative for coastal area in the northern part of Vietnam. A variety of studies have shown that the gradient in the longshore sediment transport rate and the offshore fine sediment lost are the main mechanisms causing the beach erosion. This study presents a field investigation of the beach profiles at Giao Thuy and Hai Hau beaches. Three types of empirical functions for the equilibrium beach profile are applied and compared with the observations. Results show that all observed beach profiles can be described by a single function. However, one specific equilibrium profile equation is not sufficient to assess all beach profiles. In Section 1 of Giao Thuy and Section 3 of Hai Thinh beaches, beach profiles are consistent with the logarithmic function, while the exponential function fits well in Section 2. This difference is explained with respect to coastal morphology, sediment characteristics and hydrodynamic conditions which vary in site. An analysis of the validity of the beach profile functions is recommended for the numerical modeling and engineering designs in this area. 展开更多
关键词 beach profile field study power function exponential function logarithmic function
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STRONG LIMIT THEOREMS FOR EXTENDED INDEPENDENT RANDOM VARIABLES AND EXTENDED NEGATIVELY DEPENDENT RANDOM VARIABLES UNDER SUB-LINEAR EXPECTATIONS 被引量:7
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作者 Li-Xin ZHANG 《Acta Mathematica Scientia》 SCIE CSCD 2022年第2期467-490,共24页
Limit theorems for non-additive probabilities or non-linear expectations are challenging issues which have attracted a lot of interest recently.The purpose of this paper is to study the strong law of large numbers and... Limit theorems for non-additive probabilities or non-linear expectations are challenging issues which have attracted a lot of interest recently.The purpose of this paper is to study the strong law of large numbers and the law of the iterated logarithm for a sequence of random variables in a sub-linear expectation space under a concept of extended independence which is much weaker and easier to verify than the independence proposed by Peng[20].We introduce a concept of extended negative dependence which is an extension of the kind of weak independence and the extended negative independence relative to classical probability that has appeared in the recent literature.Powerful tools such as moment inequality and Kolmogorov’s exponential inequality are established for these kinds of extended negatively independent random variables,and these tools improve a lot upon those of Chen,Chen and Ng[1].The strong law of large numbers and the law of iterated logarithm are also obtained by applying these inequalities. 展开更多
关键词 Sub-linear expectation capacity extended negative dependence Kolmogorov’s exponential inequality laws of the iterated logarithm law of large numbers
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Exponential Set-Point Stabilization of Underactuated Vehicles Moving in Three-Dimensional Space 被引量:1
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作者 Xiaodong He Zhiyong Sun +1 位作者 Zhiyong Geng Anders Robertsson 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第2期270-282,共13页
This paper investigates the stabilization of underactuated vehicles moving in a three-dimensional vector space.The vehicle’s model is established on the matrix Lie group SE(3),which describes the configuration of rig... This paper investigates the stabilization of underactuated vehicles moving in a three-dimensional vector space.The vehicle’s model is established on the matrix Lie group SE(3),which describes the configuration of rigid bodies globally and uniquely.We focus on the kinematic model of the underactuated vehicle,which features an underactuation form that has no sway and heave velocity.To compensate for the lack of these two velocities,we construct additional rotation matrices to generate a motion of rotation coupled with translation.Then,the state feedback is designed with the help of the logarithmic map,and we prove that the proposed control law can exponentially stabilize the underactuated vehicle to the identity group element with an almost global domain of attraction.Later,the presented control strategy is extended to set-point stabilization in the sense that the underactuated vehicle can be stabilized to an arbitrary desired configuration specified in advance.Finally,simulation examples are provided to verify the effectiveness of the stabilization controller. 展开更多
关键词 exponential stabilization logarithmic feedback matrix Lie group underactuated vehicle
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Exponential Synchronization of Master-Slave Lur'e Systems via Intermittent Time-Delay Feedback Control 被引量:1
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作者 王一晶 郝建娜 左志强 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第10期679-686,共8页
This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique... This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results. 展开更多
关键词 exponential synchronization intermittent control delayed feedback control Razumikhin stabilitytheory Chua's circuits
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Estimation of postseismic deformation parameters from continuous GPS data in northern Sumatra after the 2004 Sumatra-Andaman earthquake
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作者 Bimar Anugrah Irwan Meilano +1 位作者 Endra Gunawan Joni Efendi 《Earthquake Science》 CSCD 2015年第5期347-352,共6页
Continuous global positioning system (GPS) in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- ist... Continuous global positioning system (GPS) in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only. 展开更多
关键词 The 2004 Sumatra-andaman earthquakeContinuous GPS data logarithmic and exponential functions
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Public-Key Cryptosystems with Secret Encryptor and Digital Signature
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作者 Boris Verkhovsky 《International Journal of Communications, Network and System Sciences》 2013年第1期1-6,共6页
This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (prim... This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (primitive element). Modifications that simplify the cryptosystem are proposed, and, as a result, accelerate its performance. It is shown that hiding information via exponentiation is more efficient than other seemingly simpler protocols. Some of these protocols also provide digital signature/sender identification. Numeric illustrations are provided. 展开更多
关键词 Digital Signature Discrete LOGARITHM El Gamal Algorithm Generator Modular EXPONENTIATION Public Key CRYPTOSYSTEM Secure Communication SENDER Identification
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新四维耗散非线性系统动力学行为分析及电路设计
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作者 瞿民凯 汤琼 +2 位作者 赵思远 黄驿婷 罗芳文 《湖南工业大学学报》 2023年第5期17-27,共11页
在三维混沌系统的基础上,通过非线性反馈控制,构造了一个新的四维超混沌系统。分析了该系统平衡点的稳定性,运用相图、分岔图、Lyapunov指数谱、庞加莱截面图等方法,对系统随参数变化呈周期、混沌、超混沌状态的动力学行为进行了分析。... 在三维混沌系统的基础上,通过非线性反馈控制,构造了一个新的四维超混沌系统。分析了该系统平衡点的稳定性,运用相图、分岔图、Lyapunov指数谱、庞加莱截面图等方法,对系统随参数变化呈周期、混沌、超混沌状态的动力学行为进行了分析。分别利用有限元方法和Runge-Kutta方法求得该系统的数值解,并进行了对比。最后设计了该系统的模拟电路,验证了该系统的可实现性。 展开更多
关键词 超混沌系统 分岔图 LYAPUNOV指数谱 有限元方法 电路实现
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微弱光信号检测电路的实现 被引量:27
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作者 李常青 梅欣丽 明奇 《应用光学》 CAS CSCD 北大核心 2010年第5期724-727,共4页
为将微弱光信号有效地转换为电信号以方便后级电路处理,设计了微弱光信号检测电路。电路由光电转换和前置放大两部分组成。光电转换电路采用低输入偏置电流运算放大器AD 549实现;前置放大电路使用对称三极管组成的对数比率放大电路实现... 为将微弱光信号有效地转换为电信号以方便后级电路处理,设计了微弱光信号检测电路。电路由光电转换和前置放大两部分组成。光电转换电路采用低输入偏置电流运算放大器AD 549实现;前置放大电路使用对称三极管组成的对数比率放大电路实现,并在同等条件下与集成电路LOG 100组成的前置放大电路相比较。实际测量表明,该放大电路设计可有效放大低于1 nW的微弱输入信号,同时对噪声也有很强的抑制作用,而由LOG 100组成的电路对噪声的抑制能力明显衰减。 展开更多
关键词 微弱光信号 光电检测 前置放大 对数电路
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黄陵庙水文断面垂线流速分布特性研究 被引量:13
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作者 姚仕明 卢金友 徐海涛 《长江科学院院报》 CSCD 北大核心 2005年第4期8-11,共4页
为进一步利用天然河流实测资料检验垂线流速分布的指数与对数规律,采用多普勒剖面流速仪在黄陵庙水文断面中实测的不同垂线与不同流量情况下的瞬时流速资料,计算了时均流速的垂线分布,并与指数和对数流速分布公式计算的结果进行了比较... 为进一步利用天然河流实测资料检验垂线流速分布的指数与对数规律,采用多普勒剖面流速仪在黄陵庙水文断面中实测的不同垂线与不同流量情况下的瞬时流速资料,计算了时均流速的垂线分布,并与指数和对数流速分布公式计算的结果进行了比较分析。结果表明,黄陵庙水文断面不同垂线水流的时均流速分布符合对数与指数分布规律。然而,在不同水流与边界条件下,其指数公式中的指数大小与对数公式中的有关参数有所不同。通过对黄陵庙水文断面垂线流速分布特性的研究,丰富了对天然河流垂线流速分布规律的认识。 展开更多
关键词 多普勒剖面流速仪 垂线流速分布 指数流速公式 对数流速公式
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SRAM单元单粒子翻转效应的电路模拟 被引量:12
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作者 刘征 孙永节 +1 位作者 李少青 梁斌 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第1期138-141,共4页
在三维器件数值模拟的基础上,以经典的双指数模型为原型通过数值拟合得到了单粒子效应瞬态电流脉冲的表达式,在理论分析的基础上,引入了描述晶体管偏压和瞬态电流关系的方程,并将其带入电路模拟软件HSPICE中进行SRAM存储单元单粒子翻转... 在三维器件数值模拟的基础上,以经典的双指数模型为原型通过数值拟合得到了单粒子效应瞬态电流脉冲的表达式,在理论分析的基础上,引入了描述晶体管偏压和瞬态电流关系的方程,并将其带入电路模拟软件HSPICE中进行SRAM存储单元单粒子翻转效应的电路模拟,最后分别使用电路模拟和混合模拟两种方法得到了存储单元的LET阈值,通过在精度和时间开销上的对比,验证了这种模拟方法的实用性. 展开更多
关键词 单粒子翻转 双指数模型 电路模拟 器件模拟 SRAM
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山地风加速效应的计算模型 被引量:14
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作者 魏奇科 李正良 孙毅 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2010年第11期54-58,73,共6页
以往对山地风加速效应的研究及发达国家最新规范中关于山地风加速效应的计算模型往往采用指数律模型,并且只考虑了较缓的山坡,各模型中系数取值差异较大.针对这一问题,文中基于计算流体力学软件Fluent 6.2平台,利用数值模拟方法对不同... 以往对山地风加速效应的研究及发达国家最新规范中关于山地风加速效应的计算模型往往采用指数律模型,并且只考虑了较缓的山坡,各模型中系数取值差异较大.针对这一问题,文中基于计算流体力学软件Fluent 6.2平台,利用数值模拟方法对不同坡度、高度和地貌情况下的山地风加速效应进行计算,分析了山体坡度、山体高度及地貌对山地风加速效应的影响,根据数值模拟结果提出了山地平均风加速效应的对数律计算模型,拟合了模型中各参数的取值,把适用范围扩大到了较陡的山坡,并将文中模型计算结果与现有模型及规范计算结果进行比较,结果表明,对数律计算模型比指数律计算模型能更精确地描述山地近地风的加速效应. 展开更多
关键词 山地 加速效应 山体高度 山体坡度 地貌 数值模拟 指数律 对数律
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高压断路器振动信号的指数衰减振荡波建模方法 被引量:14
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作者 李庆民 王冠 +1 位作者 徐国政 钱家骊 《高压电器》 CAS CSCD 北大核心 2004年第3期177-179,共3页
分析了常规的指数衰减振荡波建模方法的实质和不足,提出了基于断路器振动信号传播中畸变现象的改进型建模方法。在频域内建立了自学习的优化建模策略,并通过实例分析初步验证了该优化策略的正确性和可行性。该建模方法为高压断路器机械... 分析了常规的指数衰减振荡波建模方法的实质和不足,提出了基于断路器振动信号传播中畸变现象的改进型建模方法。在频域内建立了自学习的优化建模策略,并通过实例分析初步验证了该优化策略的正确性和可行性。该建模方法为高压断路器机械状态的监测与诊断提供了新的理论依据和技术手段。 展开更多
关键词 高压断路器 机械振动 畸变 建模 指数衰减振荡波
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