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Some Characterizations of Upper and Lower M-Asymmetric Preirresolute Multifunctions
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作者 Levy Kahyata Matindih Elijah Bwanga Mpelele +1 位作者 Jimmy Hambulo Davy Kabuswa Manyika 《Advances in Pure Mathematics》 2023年第5期267-283,共17页
In this present paper, we introduce and investigate a new form of mappings namely;upper and lower M-asymmetric preirresolute multifunctions defined between M-structural asymmetric topological spaces. The relationships... In this present paper, we introduce and investigate a new form of mappings namely;upper and lower M-asymmetric preirresolute multifunctions defined between M-structural asymmetric topological spaces. The relationships between the multifunctions in our sense and other types of precountinuous and preirresolute multifunctions defined on both symmetric and asymmetric topological structures are discussed. 展开更多
关键词 Asymmetric-Preopen Sets M-Space M-Asymmetric Preopen Sets upper (lower) Preirresolute Multifunctions upper (lower) M-Asymmetric Preirresolute Multifunctions
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Upper and Lower Solutions for Impulsive Differential Equations with Application to ODE
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作者 綦建刚 王克宁 《Northeastern Mathematical Journal》 CSCD 2002年第3期189-196,共8页
In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one soluti... In this paper, we establish the existence of upper and lower solutions for a periodic boundary value problems (PBVP for short) of impulsive differential equations. which guarantees the existence of at least one solution for the problem. As an application, these results are applied to PBVP of ODE and some examples are given to illustrate our results. 展开更多
关键词 impulsive differential equatin upper and lower solution periodic boundary value problem
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The Estimation for Lower Bounds of the Solutions of Fermat's Equation
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作者 乐茂华 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期52-55,共4页
Let p be a prime with p≡3(mod 4). In this paper,by using some results relate the representation of integers by primitive binary quadratic forms,we prove that if x,y,z are positive integers satisfying x^p+y^p=z^p, p|x... Let p be a prime with p≡3(mod 4). In this paper,by using some results relate the representation of integers by primitive binary quadratic forms,we prove that if x,y,z are positive integers satisfying x^p+y^p=z^p, p|xyz, x<y<z, then y>p^(6p-2)/2. 展开更多
关键词 Fermat's last theorem integer solution lower bound
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Characteristics and discovery significance of the Upper Triassic–Lower Jurassic marine shale oil in Qiangtang Basin,China 被引量:1
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作者 SHEN Anjiang FU Xiaodong +13 位作者 ZHANG Jianyong WEI Xuebin HU Anping WANG Jian XIONG Shaoyun FU Xiugen XIE Yuan LIU Siqi LI Xi WANG Xin HE Xunyun QIAO Zhanfeng ZHENG Jianfeng DUAN Junmao 《Petroleum Exploration and Development》 SCIE 2023年第5期1105-1119,共15页
Mesozoic marine shale oil was found in the Qiangtang Basin by a large number of hydrocarbon geological surveys and shallow drilling sampling.Based on systematic observation and experimental analysis of outcrop and cor... Mesozoic marine shale oil was found in the Qiangtang Basin by a large number of hydrocarbon geological surveys and shallow drilling sampling.Based on systematic observation and experimental analysis of outcrop and core samples,the deposition and development conditions and characteristics of marine shale are revealed,the geochemical and reservoir characteristics of marine shale are evaluated,and the layers of marine shale oil in the Mesozoic are determined.The following geological understandings are obtained.First,there are two sets of marine organic-rich shales,the Lower Jurassic Quse Formation and the Upper Triassic Bagong Formation,in the Qiangtang Basin.They are mainly composed of laminated shale with massive mudstone.The laminated organic-rich shale of the Quse Formation is located in the lower part of the stratum,with a thickness of 50–75 m,and mainly distributed in southern Qiangtang Basin and the central-west of northern Qiangtang Basin.The laminated organic-rich shale of the Bagong Formation is located in the middle of the stratum,with a thickness of 250–350 m,and distributed in both northern and southern Qiangtang Basin.Second,the two sets of laminated organic-rich shales develop foliation,and various types of micropores and microfractures.The average content of brittle minerals is 70%,implying a high fracturability.The average porosity is 5.89%,indicating good reservoir physical properties to the level of moderate–good shale oil reservoirs.Third,the organic-rich shale of the Quse Formation contains organic matters of types II1 and II2,with the average TOC of 8.34%,the average content of chloroform bitumen'A'of 0.66%,the average residual hydrocarbon generation potential(S1+S2)of 29.93 mg/g,and the Ro value of 0.9%–1.3%,meeting the standard of high-quality source rock.The organic-rich shale of the Bagong Formation contains mixed organic matters,with the TOC of 0.65%–3.10%and the Ro value of 1.17%–1.59%,meeting the standard of moderate source rock.Fourth,four shallow wells(depth of 50–250 m)with oil shows have been found in the organic shales at 50–90 m in the lower part of the Bagong Formation and 30–75 m in the middle part of the Quse Formation.The crude oil contains a high content of saturated hydrocarbon.Analysis and testing of outcrop and shallow well samples confirm the presence of marine shale oil in the Bagong Formation and the Quse Formation.Good shale oil intervals in the Bagong Formation are observed in layers 18–20 in the lower part of the section,where the shales with(S0+S1)higher than 1 mg/g are 206.7 m thick,with the maximum and average(S0+S1)of 1.92 mg/g and 1.81 mg/g,respectively.Good shale oil intervals in the Quse Formation are found in layers 4–8 in the lower part of the section,where the shales with(S0+S1)higher than 1 mg/g are 58.8 m thick,with the maximum and average(S0+S1)of 6.46 mg/g and 2.23 mg/g,respectively. 展开更多
关键词 marine shale oil Bagong Formation upper Triassic Quse Formation lower Jurassic Biluocuo area Shiyougou area Qiangtang Basin
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A PRIORI ESTIMATE FOR LOWER SOLUTIONS OF ACLASS QUASILINEAR ELLIPTIC EQUATIONS 被引量:1
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作者 王向东 韩普宪 梁■廷 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第2期231-232,共2页
A new priori estimate of lower- solution is made for the following quasilinear elliptic equation : integral(G) {del v . A (x, u, del u) + vB (x, u, del u)} dx = 0, For All v is an element of (W) over circle(p)(1) (G).... A new priori estimate of lower- solution is made for the following quasilinear elliptic equation : integral(G) {del v . A (x, u, del u) + vB (x, u, del u)} dx = 0, For All v is an element of (W) over circle(p)(1) (G). The result presented in this paper enriches and extends the corresponding result of Gilbarg-Trudinger. 展开更多
关键词 elliptic equation lower solution priori estimate
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Upper Bound Solutions for Uplift Ultimate Bearing Capacity of Suction Caisson Foundation 被引量:1
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作者 DAI Guo-liang ZHU Wen-bo +2 位作者 ZHAI Qian GONG Wei-ming ZHAO Xue-liang 《China Ocean Engineering》 SCIE EI CSCD 2019年第6期685-693,共9页
Suction caisson foundation derives most of their uplift resistance from passive suction developed during the pullout movement. It was observed that the passive suction generated in soil at the bottom of the caisson an... Suction caisson foundation derives most of their uplift resistance from passive suction developed during the pullout movement. It was observed that the passive suction generated in soil at the bottom of the caisson and the failure mode of suction caisson foundation subjecting pullout loading behaves as a reverse compression failure mechanism.The upper bound theorems have been proved to be a powerful method to find the critical failure mechanism and critical load associated with foundations, buried caissons and other geotechnical structures. However, limited attempts have been reported to estimate the uplift bearing capacity of the suction caisson foundation using the upper bound solution. In this paper, both reverse failure mechanisms from Prandtl and Hill were adopted as the failure mechanisms for the computation of the uplift bearing capacity of the suction caisson. New equations were proposed based on both failure mechanisms to estimate the pullout capacity of the suction caisson. The proposed equations were verified by the test results and experimental data from published literature. And the two solutions agree reasonably well with the other test results. It can be proved that both failure mechanisms are reasonably and more consistent with the actual force condition. 展开更多
关键词 suction caisson foundation bearing capacity upper bound solution failure mechanism
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A Generalized Upper and Lower Solution Method for Singular Discrete Boundary Value Problems 被引量:1
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作者 胡卫敏 韦俊 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第2期212-219,共8页
This paper presents new existence results for singular discrete boundary value problems. In particular our nonlinearity may be singular in its dependent variable and is allowed to change sign.
关键词 upper and lower solutions discrete boundary value problem EXISTENCE SINGULAR
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About Upper and Lower Strong Fractional Weighted Mean Convergence by Moduli for Triple Sequences
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作者 Amelia Bucur 《Journal of Applied Mathematics and Physics》 2023年第5期1304-1318,共15页
In article, I present a study on upper and lower statistical convergence, and upper and lower strong fractional weighted mean convergence by moduli for triple sequences. One of the generalizations of the discrete oper... In article, I present a study on upper and lower statistical convergence, and upper and lower strong fractional weighted mean convergence by moduli for triple sequences. One of the generalizations of the discrete operator Cesàro, was weighted mean operators, which are linear operators, too. Given a modulus function f, I established that a triple sequence that is f-upper or lower strong fractional weighted mean convergent, in some supplementary conditions, is also f-lower or upper statistically convergent. The results of this paper adapt the results obtained in [1] and [2] to upper and lower strong fractional weighted mean convergence and to triple sequence concept. Furthermore, new concepts can be applied to the approximation theory, topology, Fourier analysis, analysis interdisciplinary with applications electrical engineering, robotics and other domains. 展开更多
关键词 upper and lower Statistical Convergence Triple Sequences Unbounded Modulus Function Numerical Analysis
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Some Results of Upper and Lower <i>M</i>-Asymmetric Irresolute Multifunctions in Bitopological Spaces 被引量:1
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作者 Levy K. Matindih Edwin Moyo +1 位作者 Davy K. Manyika Timothy Sinyangwe 《Advances in Pure Mathematics》 2021年第6期611-627,共17页
In this paper, we aim to introduce and study some basic properties of upper and lower <em>M</em>-asymmetric irresolute multifunctions defined between asymmetric sets in the realm of bitopological spaces wi... In this paper, we aim to introduce and study some basic properties of upper and lower <em>M</em>-asymmetric irresolute multifunctions defined between asymmetric sets in the realm of bitopological spaces with certain minimal structures as a generalization of irresolute functions deal to Crossley and Hildebrand <a href="#ref1">[1]</a> and upper and lower irresolute Multifunctions deal to Popa <a href="#ref2">[2]</a>. 展开更多
关键词 TiTj-Semiopen Sets M-Space M-Asymmetric Semiopen and Semiclosed Sets upper (lower) Irresolute Multifunctions and upper (lower) M-Asymmetric Irresolute Multifunctions
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Enrichment model and major controlling factors of below-source tight oil in Lower Cretaceous Fuyu reservoirs in northern Songliao Basin,NE China
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作者 WANG Xiaojun BAI Xuefeng +9 位作者 LI Junhui JIN Zhijun WANG Guiwen CHEN Fangju ZHENG Qiang HOU Yanping YANG Qingjie LI Jie LI Junwen CAI Yu 《Petroleum Exploration and Development》 SCIE 2024年第2期279-291,共13页
Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics... Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future. 展开更多
关键词 northern Songliao Basin Cretaceous Quantou Formation Qingshankou Formation upper generation and lower storage Fuyu reservoir tight oil main control factor enrichment model
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Upper and Lower Semicontinuity of Solution Sets for Parametric Generalized Vector Quasi-equilibrium Problems
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作者 LI AI-QIN FAN LI-YA 《Communications in Mathematical Research》 CSCD 2011年第1期1-5,共5页
In this paper, two kinds of parametric generalized vector quasi-equilibrium problems are introduced and the relations between them are studied. The upper and lower semicontinuity of their solution sets to parameters a... In this paper, two kinds of parametric generalized vector quasi-equilibrium problems are introduced and the relations between them are studied. The upper and lower semicontinuity of their solution sets to parameters are investigated. 展开更多
关键词 parametric generalized vector quasi-equilibrium problem solution set upper semicontinuity lower semicontinuity set-valued mapping
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Ground State Solutions for a Kind of Schrödinger-Poisson System with Upper Critical Exponential Convolution Term
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作者 Yaolan Tang Qiongfen Zhang 《Journal of Applied Mathematics and Physics》 2022年第2期576-588,共13页
This paper mainly discusses the following equation: where the potential function V : R<sup>3</sup> → R, α ∈ (0,3), λ > 0 is a parameter and I<sub>α</sub> is the Riesz potential. We stud... This paper mainly discusses the following equation: where the potential function V : R<sup>3</sup> → R, α ∈ (0,3), λ > 0 is a parameter and I<sub>α</sub> is the Riesz potential. We study a class of Schr&#246;dinger-Poisson system with convolution term for upper critical exponent. By using some new tricks and Nehair-Poho&#382;ave manifold which is presented to overcome the difficulties due to the presence of upper critical exponential convolution term, we prove that the above problem admits a ground state solution. 展开更多
关键词 Convolution Nonlinearity Schrödinger-Poisson System upper Critical Exponent Ground State solution
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Existence of Solutions for S-L Singular Boundary Value Problems with p-Laplacian Operators
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作者 郭彦平 葛渭高 单文锐 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期220-224,共5页
The existence of solutions for singular nonlinear two point boundary value problems subject to Sturm Liouville boundary conditions with p Laplacian operators is studied by the method of upper and lower solution... The existence of solutions for singular nonlinear two point boundary value problems subject to Sturm Liouville boundary conditions with p Laplacian operators is studied by the method of upper and lower solutions. The proof is based on an application of Schauder’s fixed point theorem to a modified problem whose solutions are that of the original one. At the same time, Arzela Ascoli theorem is used to prove that the defined operator N is a compact map. 展开更多
关键词 nonlinear boundary value problems p Laplacian operators fixed point upper solution lower solution
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Existence of Positive Solutions for a Class of Degenerate and Nondegenerate Stable Diffusion Models
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作者 张彦肖 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第3期50-56,共7页
This paper is concerned with a class of degenerate and nondegenerate stable diffusion models.By using the upper and lower solution method and Schauder fixed point principle,the author studies the existence of positive... This paper is concerned with a class of degenerate and nondegenerate stable diffusion models.By using the upper and lower solution method and Schauder fixed point principle,the author studies the existence of positive solutions for these stable_diffusion models under some conditions. 展开更多
关键词 weak upper and lower solutions elliptic system positive solution
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A Combination of N2 and CO2 Adsorption to Characterize Nanopore Structure of Organic-Rich Lower Silurian Shale in the Upper Yangtze Platform, South China: Implications for Shale Gas Sorption Capacity 被引量:21
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作者 CHEN Lei JIANG Zhenxue +2 位作者 LIU Keyu GAO Fenglin WANG Pengfei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第4期1380-1394,共15页
The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for the preservation and exploitation of shale gas. This study focused on the organic-rich Lower Silurian black sha... The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for the preservation and exploitation of shale gas. This study focused on the organic-rich Lower Silurian black shale from four wells in the Upper Yangtze Platform, and their TOC, mineralogical composition and pore characterization were investigated. Low pressure N2 and CO2 adsorption were conducted at 77.35 K and 273.15 K, respectively, and the pore structures were characterized by modified Brunauer-Emmett-Teller (BET), Dubinin-Radushkevich (DR), t-plot, Barrett- Joyner-Halenda (BJH) and density functional theory (DFT) methods and then the relationship between pore structure and shale gas sorption capacity was discussed. The results indicate that (1) The Lower Silurian shale has high TOC content of 0.92%~96%, high quartz content of 30.6%-69.5%, and high clays content of 24.1%-51.2%. The total specific surface area varies from 7.56 m^2/g to 25.86 m^2/g. Both the total specific surface area and quartz content are positively associated with the TOC content. (2) Shale samples with higher TOC content have more micropores, which results in more complex nanopore structure. Micropore volumes/surface areas and non-micropore surface areas all increase with the increasing TOC content. (3) A combination of N2 and CO2 adsorption provides the most suitable detection range (~0.3-60 nm) and has high reliability and accuracy for nanopore structure characterization. (4) The TOC content is the key factor to control the gas sorption capacity of the Lower Silurian shale in the Upper Yangtze Platform. 展开更多
关键词 shale gas nanopore structure lower Silurian shale upper Yangtze Platform sorption capacity
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Upper Devonian and Lower Carboniferous Sequence Stratigraphy of South China 被引量:12
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作者 Wang Xunlian Li Shilong (Department of Geology and Mineral Resources, China University of Geosciences, Beijing 100083) Wang Yue (Mineral Office of Dushan County, Dushan 558200) 《Journal of Earth Science》 SCIE CAS CSCD 1996年第1期87-94,共8页
In South China four depositional sequences are recognized in the upper part of Upper Devonian and Tournaisian. They are named SQ0 SQ1, SQ2 and SQ3 in ascending order. SQ0 is Strunian (uppermost Devonian), and the othe... In South China four depositional sequences are recognized in the upper part of Upper Devonian and Tournaisian. They are named SQ0 SQ1, SQ2 and SQ3 in ascending order. SQ0 is Strunian (uppermost Devonian), and the other three Tournaisian in age. These four depositional sequences appear to correlate fairly well with the four sequence recognized in Europe, North America and other areas. This may suggest that these sequences are synchronous depos- its resulted from the eustatic changes. The present study on sequence stratigraphy, biostratigraphy and event stratigraphy indicates that in neritic facies areas of South China, the Devonian-Carboniferous boundary, matching the boundary between Siphonodella praesulcata zone and S. sulcata zone in pelagic facies areas, is not only higher than the top of the Cystophrentis zone, but also higher than the top of the Devonian-Carboniferous boundary event bed. In neritic facies areas, the Devonian-Carbonifrerous boundary is marked by the most distinct transgressive surface within the Cystophrentiseudouralina interval zone, i. e. at the base of the TST of the SQ1. This boundary coincides with the top surface of the event bed resulted from the eustatic fall, and approximately corresponds to the basal part of Rseudouralina assemblage zone. 展开更多
关键词 sequence stratigraphy boundary upper Devonian lower Carboniferous South China.
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Ramp facies in an intracratonic basin:A case study from the Upper Devonian and Lower Carboniferous in central Hunan,southern China 被引量:6
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作者 Longyi Shao Dongdong Wang Houan Cai Hao Wang Jing Lu Pengfei Zhang 《Geoscience Frontiers》 SCIE CAS 2011年第3期409-419,共11页
Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into: (I) inner ramp peritidal platform, ... Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into: (I) inner ramp peritidal platform, (2) inner ramp organic hank and mound, (3) mid ramp, (4) outer ramp, and (5) shelf basin facies associations. The peritidal platform facies association dominates the Zimenqiao Formation (Namurian A or late Datangian) and is characterized by gypsum and dolostone-containing sequences, indicating a peritidal platform environment. The other four facies associations dominate the Menggongao Formation (late Famennian), Liujiatang Formation (Tournaisian or Yangruanian), Shidengzi Formations (early Visean or early Datangian). Five upward-shallowing cycles were distinguished in these three Formations. The predominant facies associations developed in each Formation demonstrate an overall transgression-regression cycle in the Late Devonian to Early Carboniferous in central Hunan. The overall transgressive sequence was preserved in the Shaodong, Menggongao, and Liujiatang Formations, and the overall regressive sequence was preserved in the Liujiatang, Shidengzi, Ceshui and Zimenqiao Formations. 展开更多
关键词 Intracratonic basin Carbonate ramp Southern China lower Carboniferous upper Devonian
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Controls on the organic carbon content of the lower Cambrian black shale in the southeastern margin of Upper Yangtze 被引量:5
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作者 Yu-Ying Zhang Zhi-Liang He +4 位作者 Shu Jiang Shuang-Fang Lu Dian-Shi Xiao Guo-Hui Chen Jian-Hua Zhao 《Petroleum Science》 SCIE CAS CSCD 2018年第4期709-721,共13页
Control of various factors, including mineral components, primary productivity and redox level, on the total organic carbon(TOC) in the lower Cambrian black shale from southeastern margin of Upper Yangtze(Taozichong, ... Control of various factors, including mineral components, primary productivity and redox level, on the total organic carbon(TOC) in the lower Cambrian black shale from southeastern margin of Upper Yangtze(Taozichong, Longbizui and Yanbei areas) is discussed in detail in this article. Mineral components in the study strata are dominated by quartz and clay minerals. Quartz in the Niutitang Formation is mainly of biogenic origin, and the content is in positive correlation with TOC, while the content of clay minerals is negatively correlated with TOC. Primary productivity, represented by the content of Mobio(biogenic molybdenum), Babio(biogenic barium) and phosphorus, is positively correlated with TOC. The main alkanes in studied samples are nCC, and odd–even priority values are closed to 1(0.73–1.13), which suggest the organic matter source was marine plankton. Element content ratios of U/Th and Ni/Co and compound ratio Pr/Ph indicate dysoxic–anoxic bottom water, with weak positive relative with TOC. In total, three main points can be drawn to explain the relationship between data and the factors affecting organic accumulation:(1) quartz-rich and clay-mineral-poor deep shelf–slope–basin environment was favorable for living organisms;(2) high productivity provided the material foundation for organic generation;(3) the redox conditions impact slightly on the content of organic matter under high productivity and dysoxic–anoxic condition. 展开更多
关键词 upper Yangtze lower Cambrian Black shale Total organic carbon
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Differences of Hydrocarbon Enrichment between the Upper and the Lower Structural Layers in the Tazhong Paleouplift 被引量:8
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作者 JIANG Zhenxue YANG Haijun +4 位作者 LI Zhuo PANG Xiongqi HAN Jianfa LI Dongxu HUANG Yuyan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第5期1116-1127,共12页
The Tazhong paleouplift is divided into the upper and the lower structural layers, bounded by the unconformity surface at the top of the Ordovician carbonate rock. The reservoirs in the two layers from different parts... The Tazhong paleouplift is divided into the upper and the lower structural layers, bounded by the unconformity surface at the top of the Ordovician carbonate rock. The reservoirs in the two layers from different parts vary in number, type and reserves, but the mechanism was rarely researched before. Therefore, an explanation of the mechanism will promote petroleum exploration in Tazhong paleouplift. After studying the evolution and reservoir distribution of the Tazhong paleouplift, it is concluded that the evolution in late Caledonian, late Hercynian and Himalayan periods resulted in the upper and the lower structural layers. It is also defined that in the upper structural layer, structural and stratigraphic overlap reservoirs are developed at the top and the upper part of the paleouplift, which are dominated by oil reservoirs, while for the lower structural layer, lithological reservoirs are developed in the lower part of the paleouplift, which are dominated by gas reservoirs, and more reserves are discovered in the lower structural layer than the upper. Through a comparative analysis of accumulation conditions of the upper and the lower structural layers, the mechanism of enrichment differences is clearly explained. The reservoir and seal conditions of the lower structural layer are better than those of the upper layer, which is the reason why more reservoirs have been found in the former. The differences in the carrier system types, trap types and charging periods between the upper and the lower structural layers lead to differences in the reservoir types and distribution. An accumulation model is established for the Tazhong paleouplift. For the upper structural layer, the structural reservoirs and the stratigraphic overlap reservoirs are formed at the upper part of the paleouplift, while for the lower structural layer, the weathering crust reservoirs are formed at the top, the reef-flat reservoirs are formed on the lateral margin, the karst and inside reservoirs are formed in the lower part of the paleouplift. 展开更多
关键词 the upper and the lower structural layers enrichment difference accumulation model Tazhong paleouplift
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On the upper bounds of (1,0)-super solutions for the regular balanced random (k,2s)-SAT problem
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作者 Yongping WANG Daoyun XU Jincheng ZHOU 《Frontiers of Computer Science》 SCIE EI CSCD 2024年第4期139-146,共8页
This paper explores the conditions which make a regular balancedrandom(k,2s)-CNFformula(1,O)-unsatisfiable with high probability.The conditions also make a random instance of the regular balanced(k-1,2(k-1)s)-SAT prob... This paper explores the conditions which make a regular balancedrandom(k,2s)-CNFformula(1,O)-unsatisfiable with high probability.The conditions also make a random instance of the regular balanced(k-1,2(k-1)s)-SAT problem unsatisfiable with high probability,where the instance obeys a distribution which differs from the distribution obeyed by a regular balanced random(k-1,2(k-1)s)-CNF formula.Let F be a regular balanced random(k,2s)-CNF formula where k≥3,then there exists a number so such that F is(1,O)-unsatisfiable with high probability if s>so.A numerical solution of the number so when k e(5,6,...,14)is given to conduct simulated experiments.The simulated experiments verify the theoretical result.Besides,the experiments also suggest that F is(1,O)-satisfiable with high probability if s is less than a certain value. 展开更多
关键词 regular balanced random(k 2s)-SAT problem (1 0)-super solution upper bound
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