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The Lower Orders of Dirichlet and Random Dirichlet Series 被引量:7
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作者 Yu Jiarong (Department of Mathematics,Wuhan University,Wuhan 430072,China) 《Wuhan University Journal of Natural Sciences》 CAS 1996年第1期1-8,共8页
The formulas of the lower orders of Dirichlet series are given by means of the exponents and the convex regularized sequences of the logarithms and the convex regularized sequences of the logarithms of the moduli of t... The formulas of the lower orders of Dirichlet series are given by means of the exponents and the convex regularized sequences of the logarithms and the convex regularized sequences of the logarithms of the moduli of the coefficients. Corresponding results are obtained for some random Dirichlet series. 展开更多
关键词 Dirichlet series random Dirichlet series lower order convex regularization
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THE LOWER ORDER AND LINEAR ORDER OF MULTIPLE DIRICHLET SERIES 被引量:4
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作者 梁美丽 霍颖莹 《Acta Mathematica Scientia》 SCIE CSCD 2017年第1期131-138,共8页
The article investigates the growth of multiple Dirichlet series.The lower order and the linear order of n-tuple Dirichlet series in Cn are defined and some relations between them and the coefficients and exponents of... The article investigates the growth of multiple Dirichlet series.The lower order and the linear order of n-tuple Dirichlet series in Cn are defined and some relations between them and the coefficients and exponents of n-tuple Dirichlet series are obtained. 展开更多
关键词 multiple Dirichlet series lower order linear order
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Theoretical Explanation for Lower Order Harmonic Resonance Phenomenon of Three-Ring Gear Transmissions 被引量:2
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作者 杨建明 张策 +1 位作者 林忠钦 陈关龙 《Journal of Shanghai Jiaotong university(Science)》 EI 2003年第1期71-74,共4页
Dynamic investigations revealed that lower order harmonic resonance phenomenon exists in the three ring gear transmission. That is, when the input speed is close to 1/3, 1/6, 1/9,…, 1/3 n of the primary natural frequ... Dynamic investigations revealed that lower order harmonic resonance phenomenon exists in the three ring gear transmission. That is, when the input speed is close to 1/3, 1/6, 1/9,…, 1/3 n of the primary natural frequency of the transmission, the loads on the bearings and gears are especially high. This paper explained this phenomenon from the viewpoint of parametric resonance in terms of perturbation technique. A conclusion was drawn that the basic reason for this phenomenon is the primary resonance caused by forcing excitation and parametric resonance caused by parametric change. 展开更多
关键词 three ring gear transmission lower order resonance phenomenon natural frequency primary resonance parametric resonance
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THE GENERALIZED LOWER ORDER OF DIRICHLET SERIES 被引量:1
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作者 Qingyuan CHEN Yingying HUO 《Acta Mathematica Scientia》 SCIE CSCD 2020年第4期1141-1151,共11页
In this paper,we study the generalized lower order of entire functions defined by Dirichlet series.By constructing the Newton polygon based on Knopp-Kojima’s formula,we obtain a relation between the coefficients of t... In this paper,we study the generalized lower order of entire functions defined by Dirichlet series.By constructing the Newton polygon based on Knopp-Kojima’s formula,we obtain a relation between the coefficients of the Dirichlet series and its generalized lower order. 展开更多
关键词 Dirichlet series Knopp-Kojima method Newton polygon generalized lower order
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The Lower Order and Type of Solutions of Second Order Differential Equation
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作者 ZHANG Shao-hua WU Zhao-jun SUN Dao-chun 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第1期14-21,共8页
The main purpose of this paper is to study the lower order and type of second order differential equation w"(z)-A(z)w=0,where A(z)is a polynomial.In the case of A(z)=a_dz^d,the authors prove that the lower order ... The main purpose of this paper is to study the lower order and type of second order differential equation w"(z)-A(z)w=0,where A(z)is a polynomial.In the case of A(z)=a_dz^d,the authors prove that the lower order and the type of all non-trivial solutions w of w"(z)-A(z)w=0 are equal to(d+2)/2 and(2(|a_d|)^(1/2))/(d+2)respectively.In the case of A(z)=a_dz^d+a_(d-1)z^(d-1)+…a_1z+a_0,a_d>0,a_(d-1)>0,…,a_1≥0,a_0≥0,the authors prove that the lower order of all non-trivial solutions w of w"(z)-A(z)w=0 is(d+2)/2. 展开更多
关键词 TYPE order lower order differential equation
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Existence of Solution to a Class of Elliptic Equations with Lower Order Terms and Variable Exponents
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作者 Zhongqing LI 《Journal of Mathematical Research with Applications》 CSCD 2024年第6期795-806,共12页
We study a class of nonlinear elliptic equations with nonstandard growth condition.The main feature is that two lower order terms,a non-coercive divergence term divΦ(x,u)and a gradient term H(x,u,▽u)with no growth r... We study a class of nonlinear elliptic equations with nonstandard growth condition.The main feature is that two lower order terms,a non-coercive divergence term divΦ(x,u)and a gradient term H(x,u,▽u)with no growth restriction on u,appear simultaneously in the variable exponents setting.These characteristics prevent us from directly obtaining the existence of solutions by employing the classical theory on existence results.By choosing some appropriate test functions in the perturbed problem,some a priori estimates are obtained under the variable exponent framework.Based on these estimates,we prove the almost everywhere convergence of the gradient sequence{▽u^(ε)}_(ε),which helps to pass to the limit to find a weak solution. 展开更多
关键词 elliptic equations nonstandard growth condition lower order terms weak solutions
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Construction of Split-Plot Designs with General Minimum Lower Order Confounding
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作者 Kexin Li Beichen Han Zhenzhen Niu 《Open Journal of Applied Sciences》 CAS 2023年第3期261-274,共14页
Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attracti... Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions. 展开更多
关键词 Fractional Factorial Design General Minimum lower order Confounding Criterion Split-Plot Design
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DOA Estimation Based on Sparse Representation of the Fractional Lower Order Statistics in Impulsive Noise 被引量:10
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作者 Sen Li Rongxi He +1 位作者 Bin Lin Fei Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第4期860-868,共9页
This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive ... This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive noise as α-stable distribution, new methods which combine the sparse signal representation technique and fractional lower order statistics theory are proposed. In the new algorithms, the fractional lower order statistics vectors of the array output signal are sparsely represented on an overcomplete basis and the DOAs can be effectively estimated by searching the sparsest coefficients. To enhance the robustness performance of the proposed algorithms,the improved algorithms are advanced by eliminating the fractional lower order statistics of the noise from the fractional lower order statistics vector of the array output through a linear transformation. Simulation results have shown the effectiveness of the proposed methods for a wide range of highly impulsive environments. 展开更多
关键词 α-stable distribution direction of arrival(DOA) fractional lower-order statistics impulsive noise sparse representation
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New blind estimation method of evoked potentials based on minimum dispersion criterion and fractional lower order statistics
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作者 Daifeng Zha 《Journal of Biomedical Science and Engineering》 2008年第2期91-97,共7页
Evoked potentials (EPs) have been widely used to quantify neurological system properties. Tra-ditional EP analysis methods are developed under the condition that the background noises in EP are Gaussian distributed. A... Evoked potentials (EPs) have been widely used to quantify neurological system properties. Tra-ditional EP analysis methods are developed under the condition that the background noises in EP are Gaussian distributed. Alpha stable distribution, a generalization of Gaussian, is better for modeling impulsive noises than Gaussian distribution in biomedical signal proc-essing. Conventional blind separation and es-timation method of evoked potentials is based on second order statistics or high order Statis-tics. Conventional blind separation and estima-tion method of evoked potentials is based on second order statistics (SOS). In this paper, we propose a new algorithm based on minimum dispersion criterion and fractional lower order statistics. The simulation experiments show that the proposed new algorithm is more robust than the conventional algorithm. 展开更多
关键词 EVOKED POTENTIALS (EPs) Alpha stable distribution BLIND source separation Minimum dispersion (MD) FRACTIONAL lower order statistics (FLOS)
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Some Results on Entire Functions of Finite Lower Order 被引量:7
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作者 Wu Shengjian Department of Mathematics Peking University Beijing, 100871 China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1994年第2期168-178,共11页
Let f(z) be an entire function of order λ and of finite lower order μ. If the zeros of f(z) accumulate in the vicinity of a finite number of rays, then (a) λ is finite; (b) for every arbitrary number k<... Let f(z) be an entire function of order λ and of finite lower order μ. If the zeros of f(z) accumulate in the vicinity of a finite number of rays, then (a) λ is finite; (b) for every arbitrary number k<sub>1</sub>】1, there exists k<sub>2</sub>】1 such that T(k<sub>1</sub>r, f)≤k<sub>2</sub>T(r, f) for all r≥r<sub>0</sub>. Applying the above results, we prove that if f(z) is extremal for Yang’s inequality p=g/2, then (c) every deficient value of f(z) is also its asymptotic value; (d) every asymptotic value of f(z) is also its deficient value; (e) λ=μ; (f) ∑a≠∞δ5(a, f)≤1-k(μ). 展开更多
关键词 Some Results on Entire Functions of Finite lower order
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A theory on constructing blocked two-level designs with general minimum lower order confounding 被引量:1
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作者 Yuna ZHAO Shengli ZHAO Min-Qian LIU 《Frontiers of Mathematics in China》 SCIE CSCD 2016年第1期207-235,共29页
Completely random allocation of the treatment combinations to the experimental units is appropriate only if the experimental units are homogeneous. Such homogeneity may not always be guaranteed when the size of the ex... Completely random allocation of the treatment combinations to the experimental units is appropriate only if the experimental units are homogeneous. Such homogeneity may not always be guaranteed when the size of the experiment is relatively large. Suitably partitioning inhomogeneous units into homogeneous groups, known as blocks, is a practical design strategy. How to partition the experimental units for a given design is an important issue. The blocked general minimum lower order confounding is a new criterion for selecting blocked designs. With the help of doubling theory and second order saturated design, we present a theory on constructing optimal blocked designs under the blocked general minimum lower order confounding criterion. 展开更多
关键词 Aliased effect-number pattern general minimum lower orderconfounding second order saturated design Yates order
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Lower Approximation Reduction in Ordered Information System with Fuzzy Decision 被引量:1
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作者 Xiaoyan Zhang Weihua Xu 《Applied Mathematics》 2011年第7期918-921,共4页
Attribute reduction is one of the most important problems in rough set theory. This paper introduces the concept of lower approximation reduction in ordered information systems with fuzzy decision. Moreover, the judgm... Attribute reduction is one of the most important problems in rough set theory. This paper introduces the concept of lower approximation reduction in ordered information systems with fuzzy decision. Moreover, the judgment theorem and discernable matrix are obtained, in which case an approach to attribute reduction in ordered information system with fuzzy decision is constructed. As an application of lower approximation reduction, some examples are applied to examine the validity of works obtained in our works.. 展开更多
关键词 Fuzzy DECISION lower APPROXIMATION REDUCTION orderED Information Systems ROUGH Set
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Growth of Meromorphic Solutions of Complex Linear Differential-Difference Equations with Coefficients Having the Same Order 被引量:1
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作者 Shunzhou WU Xiumin ZHENG 《Journal of Mathematical Research with Applications》 CSCD 2014年第6期683-695,共13页
The main purpose of this paper is to study the growth of meromorphic solutions of complex linear differential-difference equations L(z, f) =n∑i=0m∑j=0Aij(z)f^(j)(z + ci) = 0 or F(z)with entire or meromorp... The main purpose of this paper is to study the growth of meromorphic solutions of complex linear differential-difference equations L(z, f) =n∑i=0m∑j=0Aij(z)f^(j)(z + ci) = 0 or F(z)with entire or meromorphic coefficients, and ci, i = 0,..., n being distinct complex numbers,where there is only one dominant coefficient. 展开更多
关键词 linear differential-difference equation meromorphic solution order lower order
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A Continuous State Feedback Controller Design for High-order Nonlinear Systems with Polynomial Growth Nonlinearities 被引量:1
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作者 Guo-Dong Zhao Na Duan 《International Journal of Automation and computing》 EI CSCD 2013年第4期267-274,共8页
In this paper, we investigate the problem of global stabilization for a general class of high-order and non-smoothly stabilizable nonlinear systems with both lower-order and higher-order growth conditions. The designe... In this paper, we investigate the problem of global stabilization for a general class of high-order and non-smoothly stabilizable nonlinear systems with both lower-order and higher-order growth conditions. The designed continuous state feedback controller is recursively constructed to guarantee the global strong stabilization of the closed-loop system. 展开更多
关键词 Nonlinear systems lower-order and high-order nonlinearities state feedback adding a power integrator global strong stabilization.
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Maps to Ordered Topological Vector Spaces and Stratifiable Spaces
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作者 Erguang YANG Yun XU 《Journal of Mathematical Research with Applications》 CSCD 2018年第1期77-84,共8页
In the paper [Monotone countable paracompactness and maps to ordered topological vector spaces, Top. Appl., 2014, 169(3): 51–70], Yamazaki initiated the study on maps with values into ordered topological vector sp... In the paper [Monotone countable paracompactness and maps to ordered topological vector spaces, Top. Appl., 2014, 169(3): 51–70], Yamazaki initiated the study on maps with values into ordered topological vector spaces. Characterizations of monotonically countably paracompact spaces and some other spaces in terms of maps to ordered topological vector spaces were obtained. In this paper, following Yamazaki's method, we present some characterizations of stratifiable spaces and k-semi-stratifiable spaces in terms of maps with values into ordered topological vector spaces. 展开更多
关键词 stratifiable spaces k-semi-stratifiable spaces maps to ordered topological vector spaces lower(upper) semi-continuity
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SαS分布噪声下基于特征值调和平均的稳健频谱感知算法
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作者 杨喜 周睿勇 +4 位作者 雷可君 张耿 张银行 曹秀英 王仁玮 《湖南大学学报(自然科学版)》 北大核心 2025年第8期172-182,共11页
针对SαS分布噪声提出了一种基于分数低阶预处理与特征值调和平均检测相结合的频谱感知算法,该算法以分数低阶预处理接收信号样本协方差矩阵的最大特征值与特征值调和平均之差与最小特征值之比(DMHMM)作为感知判决量.该算法在预处理阶... 针对SαS分布噪声提出了一种基于分数低阶预处理与特征值调和平均检测相结合的频谱感知算法,该算法以分数低阶预处理接收信号样本协方差矩阵的最大特征值与特征值调和平均之差与最小特征值之比(DMHMM)作为感知判决量.该算法在预处理阶段通过分数低阶操作降低SαS分布噪声非高斯特性的影响,在检测阶段利用极值特征值与特征值调和平均设计检测判决量,检测过程避免了对噪声参数的依赖,适应范围广.在此基础上,基于Wishart矩阵特征值几何平均的矩理论,以及高维随机矩阵中最大和最小特征值渐近分布理论,针对DMHMM频谱感知算法提出了一种有效的理论判决门限计算方法,在降低理论门限计算复杂度的同时,提高了非渐近条件下SαS分布噪声中主用户信号检测结果的可靠性.Monte-Carlo仿真结果表明,所提DMHMM频谱感知算法可以获得比半盲DMGM算法更为可靠的检测判决结果,且在检测阶段无需SαS分布噪声的相关参数;由于综合利用了分数低阶预处理后取样协方差矩阵的极值特征值以及特征值调和平均信息,能够更好地反映主用户信号的变化,使得新算法具有比MME和CHME算法更优的检测效果. 展开更多
关键词 频谱感知 SαS分布噪声 分数低阶矩 特征值分布 调和平均
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基于二次分数低阶协方差的双阵元接收阵列超声波风矢量测量
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作者 刘小松 任玮 +2 位作者 单泽彪 张旭 柳鹏 《仪表技术与传感器》 北大核心 2025年第5期107-111,共5页
针对强脉冲噪声背景下超声波风速风向测量性能下降、抗噪声能力不足等问题,提出了一种基于二次分数低阶协方差的双阵元接收阵列超声波风矢量测量方法。所提方法采用一种双阵元接收阵列结构,该结构由单个发射传感器搭配2个接收传感器组成... 针对强脉冲噪声背景下超声波风速风向测量性能下降、抗噪声能力不足等问题,提出了一种基于二次分数低阶协方差的双阵元接收阵列超声波风矢量测量方法。所提方法采用一种双阵元接收阵列结构,该结构由单个发射传感器搭配2个接收传感器组成,在此结构基础上应用二次分数低阶协方差算法对超声波传播时间进行估测,并计算得出实际的风速风向。通过模拟仿真实验对所提方法进行了有效性验证,实验结果表明:所提方法对脉冲噪声具有显著的抑制效果,风速测量误差为0.27 m/s,风向角测量误差为2.7°,达到了超声波测风方法的测量标准。 展开更多
关键词 风速风向测量 脉冲噪声 二次分数低阶协方差 双阵元阵列结构
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THIRD-ORDER NONLINEAR SINGULARLY PERTURBED BOUNDARY VALUE PROBLEM 被引量:1
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作者 WANG Guo-can(王国灿) +1 位作者 JIN Li(金丽) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第6期670-677,共8页
Third order singulary perturbed boundary value problem by means of differential inequality theories is studied. Based on the given results of second order nonlinear boundary value problem, the upper and lower solution... Third order singulary perturbed boundary value problem by means of differential inequality theories is studied. Based on the given results of second order nonlinear boundary value problem, the upper and lower solutions method of third order nonlinear boundary value problems by making use of Volterra type integral operator was established. Specific upper and lower solutions were constructed, and existence and asymptotic estimates of solutions under suitable conditions were obtained. The result shows that it seems to be new to apply these techniques to solving these kinds of third order singularly perturbed boundary value problem. An example is given to demonstrate the applications. 展开更多
关键词 third order boundary value problem upper and lower solutions Volterra type integral operator existence and asymptotic estimates
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准噶尔盆地西部下二叠统沉积岩有序分布、储层特征及控制因素 被引量:2
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作者 郑孟林 王然 +8 位作者 常秋生 秦志军 王韬 何文军 郭华军 邹阳 孙靖 吴海生 单祥 《地质学报》 北大核心 2025年第12期4221-4234,共14页
准噶尔盆地西部下二叠统是全油气系统理论应用的重要实例。常-非有序分布的油气成藏模式对应着有序分布的储层类型。为明确其储层特征及控制因素,对盆地西部下二叠统50余井钻井、录井、测井、分析化验等数据进行分析。结果表明:盆地西... 准噶尔盆地西部下二叠统是全油气系统理论应用的重要实例。常-非有序分布的油气成藏模式对应着有序分布的储层类型。为明确其储层特征及控制因素,对盆地西部下二叠统50余井钻井、录井、测井、分析化验等数据进行分析。结果表明:盆地西部下二叠统沉积岩表现为从凹陷边缘至沉积中心,岩性有序、岩相有序、储集性有序。岩性依次发育粗碎屑岩、中碎屑岩和细粒沉积岩,粒度从粗至细有序、连续、依次变化。粗碎屑岩根据泥质含量的高低划分为富泥含砂砾岩相、含泥砂质砾岩相和贫泥砂质砾岩相;细粒沉积岩根据长英质和灰云质含量的高低划分为泥质岩相和云/灰质岩相。其中贫泥含砂砾岩相和云/灰质岩相储层储集性良好,分别发现规模砾岩常规油气藏和页岩油油藏。沉积相控制岩性有序分布,重力流、洪流、牵引流、异重流和异轻流动力作用与岩相有序分布密切相关。泥质杂基含量和长英质矿物组分分别对粗碎屑岩和细粒沉积岩储层储集性有决定性影响,压实成岩作用对碎屑岩储层储集性有重要影响。沉积岩有序分布及其储层性能规律性控制着油气从连续型非常规油藏向非连续型常规油藏逐步过渡。 展开更多
关键词 准噶尔盆地 下二叠统 碎屑岩 细粒沉积岩 有序分布 碱化湖盆
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Research on Outcrop Sequence Stratigraphy of Permian in Middle-Lower Yangtze Region
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作者 ZhangKexin HeWeihong 《Journal of China University of Geosciences》 SCIE CSCD 2002年第2期192-202,共11页
According to the latest International Chronostratigraphic Scheme (ICS, 2000), the Permian in the Middle Lower Yangtze region of South China can be divided into three series and nine stages relevant to the traditional... According to the latest International Chronostratigraphic Scheme (ICS, 2000), the Permian in the Middle Lower Yangtze region of South China can be divided into three series and nine stages relevant to the traditional six stages of South China. From Assellian to Changxingian of Permian, 44 Ma in age range, the strata are composed of 14 third order sequences, each of which is 3.14 Ma in average age range. There is one third order sequence of Zisongian, equivalent to middle and upper Chuanshan Formation or equal to Asselian and two thirds of Sakmarian. There are two third order sequences, corresponding to Liang shan Formation or Zhenjiang Formation and upper Chuanshan Formation, which are assigned to Longlingian, coinciding with Artinskian and one third of Sakmarian. In addition, three third order sequences, equal to Qixia Formation, are attributed to Chihsian, corresponding to Kubergandian and one third of Roadian. Four third order sequences, comprising Gufeng, Maokou, Yanqiao, Yinping and Wuxue formations, are assigned to Maokouan, equivalent to two thirds of Roadian, Wordian and Capitanian. Two third order sequences, equal to Longtan Formation or Wujiaping Formation, are included in Wuchiapingian. Other two third order sequences, corresponding to Changxing Formation or Dalong Formation, are assigned to Changhsingian. In brief, these above third order sequences can be incorporated into 4 sequences sets. 展开更多
关键词 systems tract third order sequence sea level changes PERMIAN Middle lower Yangtze region.
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