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Carboniferous and Permian integrative stratigraphy and timescale of North China Block

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Science China Earth Sciences 2022年第6期65卷 983-1011页

作者： Boheng SHEN Shuzhong SHEN Qiong WU Shuichang ZHANG Bin ZHANG Xiangdong WANG Zhangshuai hou Dongxun YUAN Yichun ZHANG feng LIU jun LIU Hua ZHANG Yukun SHI jun WANG Zhuo feng State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering and Frontiers Science Center for Critical Earth Material CyclingNanjing UniversityNanjing 210023China Research Institute of Petroleum Exploration and Development PetroChinaBeijing 100083China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesBeijing 100044China Institute of Palaeontology Yunnan UniversityKunming 650500China

The Carboniferous-Permian strata in the North China Block(NCB) contain abundant fossils, coals and natural *** a high-resolution timescale for the Carboniferous and Permian in the NCB is essential to understand the geologic events and explore the spatial and temporal distributions of the natural resources. The upper Carboniferous and the basal part of Permian are relatively well correlated because they yield marine conodont and fusuline fossils. However, the Permian terrestrial strata mostly rely on poorly constrained palynostratigraphy and phytostratigraphy and are short of the precise geochronologic constraints on the correlation with the marine strata. This study provides a critical review on the state-of-the-art of the latest Carboniferous and Permian chronostratigraphic and biostratigraphic frameworks and stratigraphic correlation in the NCB. The Penchi Formation ranges from lower Bashkirian to lower Gzhelian;the Taiyuan Formation is assigned to the upper Gzhelian to lower Asselian;the Shansi and Lower Shihhotse formations are from middle Asselian to lower Sakmarian;the Upper Shihhotse Formation is assigned to upper Artinskian to lower Kungurian, and the Sunjiagou Formation was assigned to Lopingian, respectively. A long hiatus up to ~20 Myr between the Upper Shihhotse and Sunjiagou formations, mainly marked by a large-scale erosional surface at the base of a coarse conglomeratic sandstone unit and/or multiple paleosol layers as well as significant differences of floras between these two lithostratigraphic units, is present probably due to tectonic uplift in association with the closure of the Paleo Asian Ocean(PAO) during the Cisuralian and Guadalupian. The possible amplitude of sea-level changes from Carboniferous to Permian on the NCB is estimated from 0 to 40 *** floral succession, depositional records and organic carbon isotope profiles suggest that the latest Carboniferous and earliest Permian was a favorable period for coal accumulation

关键词： North China Block Carboniferous-Permian Geochronology Biostratigraphy Correlation

Every Toroidal Graph Is Acyclically 8-Choosable

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Acta Mathematica Sinica,English Series 2014年第2期30卷 343-352页

作者： Jian feng hou Gui Zhen LIU Center for Discrete Mathematics Fuzhou University School of Mathematics Shandong University

A proper coloring of a graphG is acyclic if G contains no 2-colored cycle.A graph G is acyclically L-list colorable if for a given list assignment L={L（v）：v∈V（G）},there exists a proper acyclic coloringφof G such thatφ（v）∈L（v）for all v∈V（G）.If G is acyclically L-list colorable for any list assignment L with｜L（v）｜≥k for all v∈V（G）,then G is acyclically *** this article,we prove that every toroidal graph is acyclically 8-choosable.

关键词： Acyclic coloring choosability toroidal graph

Atmospheric Circulation Patterns over East Asia and Their Connection with Summer Precipitation and Surface Air Temperature in Eastern China during 1961–2013

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Journal of Meteorological Research 2018年第2期32卷 203-218页

作者： Shuping LI Wei hou Guolin feng College of Atmospheric Sciences Lanzhou University Lanzhou 730000 National Climate Center China Meteorological Administration Beijing 100081 College of Physical Science and Technology Yangzhou University Yangzhou 225000

Based on the NCEP/NCAR reanalysis data and Chinese observational data during 1961–2013, atmospheric circulation patterns over East Asia in summer and their connection with precipitation and surface air temperature in eastern China as well as associated external forcing are investigated. Three patterns of the atmospheric circulation are identified, all with quasi-barotropic structures：（1） the East Asia/Pacific（EAP） pattern,（2） the Baikal Lake/Okhotsk Sea（BLOS） pattern, and（3） the eastern China/northern Okhotsk Sea（ECNOS） pattern. The positive EAP pattern significantly increases precipitation over the Yangtze River valley and favors cooling north of the Yangtze River and warming south of the Yangtze River in summer. The warm sea surface temperature anomalies over the tropical Indian Ocean suppress convection over the northwestern subtropical Pacific through the Ekman divergence induced by a Kelvin wave and excite the EAP pattern. The positive BLOS pattern is associated with below-average precipitation south of the Yangtze River and robust cooling over northeastern China. This pattern is triggered by anomalous spring sea ice concentration in the northern Barents Sea. The anomalous sea ice concentration contributes to a Rossby wave activity flux originating from the Greenland Sea, which propagates eastward to North Pacific. The positive ECNOS pattern leads to below-average precipitation and significant warming over northeastern China in summer. The reduced soil moisture associated with the earlier spring snowmelt enhances surface warming over Mongolia and northeastern China and the later spring snowmelt leads to surface cooling over Far East in summer, both of which are responsible for the formation of the ECNOS pattern.

关键词： atmospheric circulation patterns precipitation surface air temperature external forcing

Convergence analysis of the corrected Uzawa algorithm for symmetric saddle point problems

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Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 29-35页

作者： LU jun-feng Hangzhou Institute of Commerce Zhejiang Gongshang University

For the large sparse saddle point problems, Pan and Li recently proposed in [H. K. Pan, W. Li, Math. Numer. Sinica, 2009, 31（3）： 231-242] a corrected Uzawa algorithm based on a nonlinear Uzawa algorithm with two nonlinear approximate inverses, and gave the detailed convergence analysis. In this paper, we focus on the convergence analysis of this corrected Uzawa algorithm, some inaccuracies in [H. K. Pan, W. Li, Math. Numer. Sinica, 2009, 31（3）： 231-242] are pointed out, and a corrected convergence theorem is presented. A special case of this modified Uzawa algorithm is also discussed.

关键词： Saddle point problem Uzawa algorithm convergence analysis

Interpolation and Convergence of Bernstein-Bezier Coefficients

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Acta Mathematica Sinica,English Series 2011年第9期27卷 1769-1782页

作者： feng jun LI School of Mathematics and Computer Science Ningxia University Yinchuan 750021 P. R. China

In this paper, two ways of the proof are given for the fact that the Bernstein-Bezier coefficients （BB-coefficients） of a multivariate polynomial converge uniformly to the polynomial under repeated degree elevation over the simplex. We show that the partial derivatives of the inverse Bernstein polynomial An （g） converge uniformly to the corresponding partial derivatives of g at the rate 1/n. We also consider multivariate interpolation for the BB-coefficients, and provide effective interpolation formulas by using Bernstein polynomials with ridge form which essentially possess the nature of univariate polynomials in computation, and show that Bernstein polynomials with ridge form with least degree can be constructed for interpolation purpose, and thus a computational algorithm is provided correspondingly.

关键词： Interpolation convergence BB-coefficients ridge function simplex

Moderate Deviations for Stochastic Heat Equation with Rough Dependence in Space

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Acta Mathematica Sinica,English Series 2019年第9期35卷 1491-1510页

作者： jun feng LIU School of Statistics and Mathematics Nanjing Audit University

In this paper, we establish a moderate deviation principle for the stochastic heat equation driven by a Gaussian noise which is white in time and which has the covariance of a fractional Brownian motion with Hurst par... 详细信息

关键词： Stochastic heat equation fractional Brownian motion moderate deviations weak convergence approach

Stability of Nonlinear Wave of Kadomtsev-Petviashvili-Type Equation

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Communications in Theoretical Physics 2007年第2期47卷 333-338页

作者： feng Tian-jun Department of Physics Lanzhou Jiao Tong University Lanzhou 730070 China

For ion-acoustic waves in a plasma with non-isothermal electrons, the MKP equation is its governing equation. The instability of a soliton solution of MKP equation to two-dimensional long-wavelength perturbations is investigated up to the third order. It indicates that the one-soliton solution of MKP equation is unstable if v = -1 wheras it is stable if v = 1 until the third order approximation has been considered.

关键词： MKP equation stability solitary waves

Biased Partitions and Judicious k-Partitions of Graphs

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Acta Mathematica Sinica,English Series 2017年第5期33卷 668-680页

作者： Qing hou ZENG Jian feng hou Jin DENG Xia LEI Center for Discrete Mathematics Fuzhou University Fuzhou 350003 P. R. China Hu'nan College of Information Changsha 410200 P. R. China School of Software Engineering Xiamen University of Technology Xiamen 361024 P. R. China

Let G =（V, E） be a graph with m edges. For reals p ∈ [0, 1] and q = 1-p, let m;（G） be the minimum of qe（V;） + pe（V;） over partitions V = V;∪ V;, where e（V;） denotes the number of edges spanned by V;. We show that if m;（G） = pqm-δ, then there exists a bipartition V;, V;of G such that e（V;） ≤ p;m-δ + p（m/2）;+ o（√m） and e（V;） ≤ q;m-δ + q（m/2）;+ o（√m） for δ = o(m;). This is sharp for com;lete graphs up to the error term o（√m）. For an integer k ≥ 2, let fk（G） denote the maximum number of edges in a k-partite subgraph of G. We prove that if fk（G） =（1-1/k）m + α,then G admits a k-partition such that each vertex class spans at most m/k;-Ω(m/k;) edges forα = Ω（m/k;）. Both of the above im;rove the results of Bollob′as and Scott.

关键词： Graph Max-Cut biased partition judicious partition

The Estimates for Sharp Maximal Functions of Multilinear Strongly Singular Integral Operators

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Acta Mathematica Sinica,English Series 2005年第6期21卷 1495-1508页

作者： jun feng LI Department of Mathematics Beijing Normal University Beijing 100875 P. R. China

In this paper, the author obtains that the multilinear operators of strongly singular integral operators and their dual operators are bounded from some L^p（R^n） to L^p（R^n） when the m-th order derivatives of A belong to L^p（R^n） for r large enough. By this result, the author gets the estimates for the Sharp maximal functions of the multilinear operators with the m-th order derivatives of A being Lipschitz functions. It follows that the multilinear operators are （L^p, L^p）-type operators for 1 〈 p 〈 ∞.

关键词： Multilinear operators Lipschitz functions L^p(R^n) Lipschitz