Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Alta...Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Altay and Basar [5] and Altay, Basar, and Mursaleen [7] introduced the Euler sequence spaces e0^r, ec^r, and e∞^r, respectively. The main purpose of this article is to introduce the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））consisting of all sequences whose mth order differences are in the Euler spaces e0^r, ec^r, and e∞^r, respectively. Moreover, the authors give some topological properties and inclusion relations, and determine the α-, β-, and γ-duals of the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））, and the Schauder basis of the spaces e0^r△^（m））, ec^r△^（m））. The last section of the article is devoted to the characterization of some matrix mappings on the sequence space ec^r△^（m））.展开更多
Here presented is a matrix representation of recursive number sequences of order 3 defined by an = pa（n-1） ＋ qa（n-2） ＋ ra（n-3） with arbitrary initial conditions a0, a1 = 0, and a2 and their special cases of Pa...Here presented is a matrix representation of recursive number sequences of order 3 defined by an = pa（n-1） ＋ qa（n-2） ＋ ra（n-3） with arbitrary initial conditions a0, a1 = 0, and a2 and their special cases of Padovan number sequence and Perrin number sequence with initial conditions a0 = a1 = 0 and a2 = 1 and a0 = 3, a1 = 0, and a2 = 2, respectively. The matrix representation is used to construct many well known and new identities of recursive number sequences as well as Pavodan and Perrin sequences.展开更多
In the past, several authors studied spaces of m-th order difference sequences, among them, H.Polat and F.Basar （[17]） defined the Euler spaces of m-th order difference sequences e r 0 （△ （ m ） ）, e r c （△ （...In the past, several authors studied spaces of m-th order difference sequences, among them, H.Polat and F.Basar （[17]） defined the Euler spaces of m-th order difference sequences e r 0 （△ （ m ） ）, e r c （△ （ m ） ） and e r ∞ （△ （ m ） ） and characterized some classes of matrix transformations on them. In our paper, we add a new supplementary aspect to their research by characterizing classes of compact operators on those spaces. For that purpose, the spaces are treated as the matrix domains of a triangle in the classical sequence spaces c 0 , c and ∞ . The main tool for our characterizations is the Hausdorff measure of noncompactness.展开更多
There are complex and regular changes on sedimentary facies from the Early to the Middle Triassic in the Nanpanjiang basin. After the obvious drowned event of carbonate platforms in the transitional period between Per...There are complex and regular changes on sedimentary facies from the Early to the Middle Triassic in the Nanpanjiang basin. After the obvious drowned event of carbonate platforms in the transitional period between Permian and Triassic, carbonate platforms have evolved into the ramp type from the rimmed shelf type. The differentiation of sedimentary facies becomes clearer in space, which are marked by the changes from an attached platform to a turbidity basin and several isolated platforms in the basin. The striking characteristics are the development of oolitic banks on isolated platforms in Nanning and Jingxi and the reef and bank limestones in the margin of the attached platform in the Early Triassic. Despite the difference of the time span and the architecture of facies succession of third order sedimentary sequences, the process of the third order relative sea level changes reflected by the sedimentary facies succession of the third order sequences is generally synchronous. Therefore, six third order sequences could be discerned in the strata from the Early to the Middle Triassic in the Nanpanjiang basin. Using two types of facies changing surfaces and two types of diachronisms in stratigraphic records as the key elements, the sedimentary facies architectures of the third order sequences that represent sequence stratigraphic frameworks from the Early to the Middle Triassic in the Nanpanjiang basin could be constructed.展开更多
The main result of this paper is the identification of the sequential order dual [∧(X)]so containing sequentially order continuous linear functionals on the ordered generalized sequence space ∧(X) with its generaliz...The main result of this paper is the identification of the sequential order dual [∧(X)]so containing sequentially order continuous linear functionals on the ordered generalized sequence space ∧(X) with its generalized Kothe dual ∧x(Xso), defined corresponding to the dual pair <X, Xso>.展开更多
Based on the study of stratigraphic sedimentary facies of the prototype sedimentary basin formed in the Late Devonian to Permian Period in the Tarim Basin, the prototype sedimentary basin are divided into five order s...Based on the study of stratigraphic sedimentary facies of the prototype sedimentary basin formed in the Late Devonian to Permian Period in the Tarim Basin, the prototype sedimentary basin are divided into five order sequences according to the theory of sequence stratigraphy. It is considered that the Upper Devonian–Lower Carboniferous shore-mixing shelf in the lower part of the prototype sedimentary basin is a typical third-order sequence and a sequence development model is established. The third-order sequence is actually a transgression systems tract and highstand systems tract cycle assemblage, and the type I sequence(no lowstand systems tract) is a typical developmental mode of the third order sequence, and the identification mark is the existence of huge mudstone and limestone wedges from sea to land. The fifth-order parasequence is the basic sequence, which is a single cycle sequence. The thin layer limestone isochronous sediments, which are easy to be identified in the mixed shelf areas, are the isochronous sediments of the largest or secondary marine-flooding surface. The mixed shelf area belongs to the equilibrium sedimentary profile of internal and external sediments, and there is no condensed section. The inclined deposition phenomenon of extraneous source sediments in the sea area weakens or disappears in the mixed shelf area. The paleogeomorphology at the bottom of the third-order sequence is a terrace-slope break zone. This paleogeomorphological feature is not only the main reason for the sedimentary diachronism of Donghe sandstone, but also the main reason for the formation of the transgression-highstand fourth-order cyclic sequences of the Donghe sandstone section and its upper gravel-bearing sandstone section.展开更多
In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.I...In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained.展开更多
In this paper we introduce two sequences of operator functions and their dualfunctions： fk（t） = （flogt）k-（t-1）k/log^k＋2t （k = 1,2,...）, gk（t） = （t-1）k-logkt /log^k＋1t （k = 1,2,...） and fk（t）tklog^k...In this paper we introduce two sequences of operator functions and their dualfunctions： fk（t） = （flogt）k-（t-1）k/log^k＋2t （k = 1,2,...）, gk（t） = （t-1）k-logkt /log^k＋1t （k = 1,2,...） and fk（t）tklog^k＋1t/（tlogt）k-（t-1）^k（k=1,2…）,gk（t）=t^klog^k＋1t/（t-1）^k-log^kt（k=1,2…）defined onWe find that they are all operator monotone functions with respect to the strictly chaoticorder and some ordinary orders among positive invertible operators. Indeed, we extend theresults of the operator monotone function tlogt-t＋1/log^2t which is widely used in the theory of heat transfer of the heat engineering and fluid mechanics[1].展开更多
Type division and controlling factor analysis of 3rd-order sequence are of practical significance to tec-tonic analysis, sedimentary environment identification, and other geological researches. Based on the comprehens...Type division and controlling factor analysis of 3rd-order sequence are of practical significance to tec-tonic analysis, sedimentary environment identification, and other geological researches. Based on the comprehensive analysis of carbon and oxygen isotope trends, paleobathymetry and spectral-frequency of representative well logs, 3rd-order sequences can be divided into 3 types： （a） global sea level （GSL） sequence mainly controlled by GSL change;（b） tectonic sequence mainly controlled by regional tectonic activity;and （c） composite sequence jointly controlled by GSL change and regional tectonic activity. This study aims to identify the controlling factors of 3rd-order sequences and to illustrate a new method for classification of 3rd-order sequences of the middle Permian strata in the Sichuan Basin, China. The middle Permian strata in the Sichuan Basin consist of 3 basin-contrastive 3rd-order sequences, i.e., PSQ1, PSQ2 and PSQ3. Of these, PSQ1 is a GSL sequence while PSQ2 and PSQ3 are composite sequences. The results suggest that the depositional environment was stable during the deposition of PSQ1, but was activated by tectonic activity during the deposition of the middle Permian Maokou Formation.展开更多
For the sequences satisfying the recurrence relation of the second order,the generating functions for the products of the powers of these sequences are established.This study was from Carlita and Riordan who began a s...For the sequences satisfying the recurrence relation of the second order,the generating functions for the products of the powers of these sequences are established.This study was from Carlita and Riordan who began a study on closed form of generating functions for powers of second-order recurrence sequences.This investigation was completed by Stnica.Inspired by the recent work of Istva＇n about the non-closed generating functions of the products of the powers of the second-order sequences,the authors give several extensions of Istva＇n＇s results in this paper.展开更多
The boundary value problem of plate bending problem on two_parameter foundation was discussed.Using two series of the high_order fundamental solution sequences, namely, the fundamental solution sequences for the multi...The boundary value problem of plate bending problem on two_parameter foundation was discussed.Using two series of the high_order fundamental solution sequences, namely, the fundamental solution sequences for the multi_harmonic operator and Laplace operator, applying the multiple reciprocity method(MRM), the MRM boundary integral equation for plate bending problem was constructed. It proves that the boundary integral equation derived from MRM is essentially identical to the conventional boundary integral equation. Hence the convergence analysis of MRM for plate bending problem can be obtained by the error estimation for the conventional boundary integral equation. In addition, this method can extend to the case of more series of the high_order fundamental solution sequences.展开更多
A probabilistic progressive failure analyzing method is applied to estimating the reliability of a simply supported laminated composite plate with an initial imperfection under bi-axial compression load. The initial i...A probabilistic progressive failure analyzing method is applied to estimating the reliability of a simply supported laminated composite plate with an initial imperfection under bi-axial compression load. The initial imperfection and the strength parameters are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method (FORM) together with the Tsai-Wu strength criterion and Tan criterion. Current stresses in the laminated structure are calculated by the classical lamination theory with the stiffness modified based on the last step ply failure. Probabilistically dominant ply-level failure sequences leading to overall system failure are identified, based on which the system failure probability is estimated. A numerical example is presented to demonstrate the methodology proposed. Through parameter studies it is shown that the deviation of the initial imperfection and some of the strength parameters largely influence the system reliability.展开更多
In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are pr...In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are preferred by researchers. Under the guidance of the theory of sequence stratigraphy, the findings of this paper indicate that climate is a major factor controlling the formation of the fourth-order sequence, based upon the study of the sequence stratigraphy in the Green River Formation of the Uinta basin in the USA. It also divides the fourth-order sequence in the terrestrial lacustrine basin into two system tracts： the wet （rising） half-cycle and the dry （falling） half- cycle, establishing a new-style fourth-order sequence stratigraphic model for the terrestrial lacustrine basin, that is, the climate-genetic sequence stratigraphic model. As a result, the theory of sequence stratigraphy is greatly enriched.展开更多
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
Based on isotopic, lithologic and electrical data and logging cycle analysis technique, stratigraphic sequences in the Middle-Upper Cambrian Xixiangchi Group in the Sichuan Basin and its adjacent area are divided, and...Based on isotopic, lithologic and electrical data and logging cycle analysis technique, stratigraphic sequences in the Middle-Upper Cambrian Xixiangchi Group in the Sichuan Basin and its adjacent area are divided, and its sedimentary characteristics and evolution are analyzed. The Xixiangchi Group can be divided into 5 third-order sequences(Sql-Sq5), of which sequences Ⅰ to Ⅲ(Sql-Sq3) are relatively complete, sequences Ⅳ and Ⅴ are denuded in the Late Cambrian because of the Dian-Chuan paleo-uplifts.Third-order sequences of the Xixiangchi Group in this area have the characteristics of thin in the west and thick in the east, showing that the Caledonian paleo-uplift is a synsedimentary paleo-uplift and the paleogeomorphology in the platform is a gentle slope. Sequence Ⅰdevelops high stand systems tract and transgressive systems tract. The other third-order sequences are dominated by highstand systems tracts, and the transgressive systems tracts last shortly in time and are limited in area. The basic features of evaporative-restricted platform of gentle slope type developed continuously in the sedimentary period of the Xixiangchi Group, its sedimentary environment of "high in west and low in east" and the change of micro paleogeomorphology in the platform control the continuous development of sedimentary facies. Open platform is developed only in sequence Ⅰ and sequence Ⅱ, and the inner beach of the platform and the edge beach of the platform are mostly developed in sequence Ⅱ and sequence Ⅲ. It indicates that there are two platform margin zones in the study area,a relatively stable, large-scale platform marginal zone in NE Guizhou-Western Hunan and Hubei, and a moving and small-scale platform marginal zone in North Chongqing-Western Hubei.展开更多
The rapid growth of blockchain and Decentralized Finance(DeFi)has introduced new challenges and vulnerabilities that threaten the integrity and efficiency of the ecosystem.This study identifies critical issues such as...The rapid growth of blockchain and Decentralized Finance(DeFi)has introduced new challenges and vulnerabilities that threaten the integrity and efficiency of the ecosystem.This study identifies critical issues such as Transaction Order Dependence(TOD),Blockchain Extractable Value(BEV),and Transaction Importance Diversity(TID),which collectively undermine the fairness and security of DeFi systems.BEV-related activities,including sandwich attacks,liquidations,transaction replay etc.have emerged as significant threats,collectively generating$540.54 million in losses over 32 months across 11,289 addresses,involving 49,691 cryptocurrencies and 60,830 on-chain markets.These attacks exploit transaction mechanics to manipulate asset prices and extract value at the expense of other participants,with sandwich attacks being particularly impactful.Additionally,the growing adoption of blockchain in traditional finance highlights the challenge of TID,wherein high transaction volumes can strain systems and compromise time-sensitive operations.To address these pressing issues,we propose a novel Distributed Transaction Sequencing Strategy(DTSS)that integrates forking mechanisms with an Analytic Hierarchy Process(AHP)to enforce fair and transparent transaction ordering in a decentralized manner.Our approach is further enhanced by an optimization framework and the introduction of a Normalized Allocation Disparity Metric(NADM)that ensures optimal parameter selection for transaction prioritization.Experimental evaluations demonstrated that the DTSS effectively mitigated BEV risks,enhanced transaction fairness,and significantly improved the security and transparency of DeFi ecosystems.展开更多
Under the guidance of the whole petroleum system theory,using seismic,drilling and laboratory analysis data,and combined with the practical achievements of oil and gas exploration,the distribution patterns of differen...Under the guidance of the whole petroleum system theory,using seismic,drilling and laboratory analysis data,and combined with the practical achievements of oil and gas exploration,the distribution patterns of different types of natural gas in the deep-water area of the Qiongdongnan Basin of China were systematically reviewed,the orderly symbiosis mechanisms and hydrocarbon accumulation processes of diverse gas reservoirs were analyzed,and a composite whole petroleum system model for the deep-water strongly active basins in the northern South China Sea was constructed.In the deep-water area of the Qiongdongnan Basin,there are three sets of source rocks,namely the Eocene,the Oligocene,and the upper Miocene-Quaternary,and three whole petroleum systems can be accordingly classified.The source rocks have the characteristics of multilayers,multiple types,and multiple hydrocarbon generation centers.The Eocene lacustrine source rocks,Oligocene marine and continental dual-origin source rocks,and upper Miocene-Quaternary marine source rocks form multiple hydrocarbon generation centers,which are orderly distributed from east to west.The reservoirs are characterized by multiple geological ages,multiple rock types,and multiple hydrodynamic influences,and exist as a reservoir composite superposition pattern with basement buried hill-lower traction flow sandbody-upper gravity flow sandbody vertically in the deep-water area.Fluid activities within the basin are controlled by free dynamic fields,confined dynamic fields,and bound dynamic fields.The natural gas in the whole petroleum system presents an orderly distribution of shale gas(speculated)-tight gas-conventional gas-ultra-shallow gas-hydrate from bottom to top.The research results have verified the adaptability of the whole petroleum system theory in the deep-water area of the Qiongdongnan Basin,providing a theoretical support for the exploration of complex oil and gas resources in the deep-water area,and are expected to effectively guide the distribution prediction and exploration of different types of petroleum resources in deep-water areas.展开更多
文摘Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Altay and Basar [5] and Altay, Basar, and Mursaleen [7] introduced the Euler sequence spaces e0^r, ec^r, and e∞^r, respectively. The main purpose of this article is to introduce the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））consisting of all sequences whose mth order differences are in the Euler spaces e0^r, ec^r, and e∞^r, respectively. Moreover, the authors give some topological properties and inclusion relations, and determine the α-, β-, and γ-duals of the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））, and the Schauder basis of the spaces e0^r△^（m））, ec^r△^（m））. The last section of the article is devoted to the characterization of some matrix mappings on the sequence space ec^r△^（m））.
文摘Here presented is a matrix representation of recursive number sequences of order 3 defined by an = pa（n-1） ＋ qa（n-2） ＋ ra（n-3） with arbitrary initial conditions a0, a1 = 0, and a2 and their special cases of Padovan number sequence and Perrin number sequence with initial conditions a0 = a1 = 0 and a2 = 1 and a0 = 3, a1 = 0, and a2 = 2, respectively. The matrix representation is used to construct many well known and new identities of recursive number sequences as well as Pavodan and Perrin sequences.
基金supported by the research project#144003 of the Serbian Ministry of Science, Technology and Development
文摘In the past, several authors studied spaces of m-th order difference sequences, among them, H.Polat and F.Basar （[17]） defined the Euler spaces of m-th order difference sequences e r 0 （△ （ m ） ）, e r c （△ （ m ） ） and e r ∞ （△ （ m ） ） and characterized some classes of matrix transformations on them. In our paper, we add a new supplementary aspect to their research by characterizing classes of compact operators on those spaces. For that purpose, the spaces are treated as the matrix domains of a triangle in the classical sequence spaces c 0 , c and ∞ . The main tool for our characterizations is the Hausdorff measure of noncompactness.
基金ThestudyisjointlysupportedbytheChinaPetroleumCorporation (No .NPJ- 10 0 19)andalsobytheMinistryofScienceandTechnology (SSER)
文摘There are complex and regular changes on sedimentary facies from the Early to the Middle Triassic in the Nanpanjiang basin. After the obvious drowned event of carbonate platforms in the transitional period between Permian and Triassic, carbonate platforms have evolved into the ramp type from the rimmed shelf type. The differentiation of sedimentary facies becomes clearer in space, which are marked by the changes from an attached platform to a turbidity basin and several isolated platforms in the basin. The striking characteristics are the development of oolitic banks on isolated platforms in Nanning and Jingxi and the reef and bank limestones in the margin of the attached platform in the Early Triassic. Despite the difference of the time span and the architecture of facies succession of third order sedimentary sequences, the process of the third order relative sea level changes reflected by the sedimentary facies succession of the third order sequences is generally synchronous. Therefore, six third order sequences could be discerned in the strata from the Early to the Middle Triassic in the Nanpanjiang basin. Using two types of facies changing surfaces and two types of diachronisms in stratigraphic records as the key elements, the sedimentary facies architectures of the third order sequences that represent sequence stratigraphic frameworks from the Early to the Middle Triassic in the Nanpanjiang basin could be constructed.
文摘The main result of this paper is the identification of the sequential order dual [∧(X)]so containing sequentially order continuous linear functionals on the ordered generalized sequence space ∧(X) with its generalized Kothe dual ∧x(Xso), defined corresponding to the dual pair <X, Xso>.
文摘Based on the study of stratigraphic sedimentary facies of the prototype sedimentary basin formed in the Late Devonian to Permian Period in the Tarim Basin, the prototype sedimentary basin are divided into five order sequences according to the theory of sequence stratigraphy. It is considered that the Upper Devonian–Lower Carboniferous shore-mixing shelf in the lower part of the prototype sedimentary basin is a typical third-order sequence and a sequence development model is established. The third-order sequence is actually a transgression systems tract and highstand systems tract cycle assemblage, and the type I sequence(no lowstand systems tract) is a typical developmental mode of the third order sequence, and the identification mark is the existence of huge mudstone and limestone wedges from sea to land. The fifth-order parasequence is the basic sequence, which is a single cycle sequence. The thin layer limestone isochronous sediments, which are easy to be identified in the mixed shelf areas, are the isochronous sediments of the largest or secondary marine-flooding surface. The mixed shelf area belongs to the equilibrium sedimentary profile of internal and external sediments, and there is no condensed section. The inclined deposition phenomenon of extraneous source sediments in the sea area weakens or disappears in the mixed shelf area. The paleogeomorphology at the bottom of the third-order sequence is a terrace-slope break zone. This paleogeomorphological feature is not only the main reason for the sedimentary diachronism of Donghe sandstone, but also the main reason for the formation of the transgression-highstand fourth-order cyclic sequences of the Donghe sandstone section and its upper gravel-bearing sandstone section.
基金Supported by the National Natural Science Foundation of China(11501250)Zhejiang Provincial Natural Science Foundation of China(LY18A010020)Innovation of Jiaxing City:a program to support the talented persons。
文摘In this paper,we study the asymptotic relation between the first crossing point and the last exit time for Gaussian order statistics which are generated by stationary weakly and strongly dependent Gaussian sequences.It is shown that the first crossing point and the last exit time are asymptotically independent and dependent for weakly and strongly dependent cases,respectively.The asymptotic relations between the first crossing point and the last exit time for stationary weakly and strongly dependent Gaussian sequences are also obtained.
文摘In this paper we introduce two sequences of operator functions and their dualfunctions： fk（t） = （flogt）k-（t-1）k/log^k＋2t （k = 1,2,...）, gk（t） = （t-1）k-logkt /log^k＋1t （k = 1,2,...） and fk（t）tklog^k＋1t/（tlogt）k-（t-1）^k（k=1,2…）,gk（t）=t^klog^k＋1t/（t-1）^k-log^kt（k=1,2…）defined onWe find that they are all operator monotone functions with respect to the strictly chaoticorder and some ordinary orders among positive invertible operators. Indeed, we extend theresults of the operator monotone function tlogt-t＋1/log^2t which is widely used in the theory of heat transfer of the heat engineering and fluid mechanics[1].
基金key project carried out in 2008-2011financially supported by the National Major Special Science and Technology Project (Grant No. 2008ZX05004-001)Major Special Issue of the China National Petroleum Corporation (Grant No. 2008E-0702)
文摘Type division and controlling factor analysis of 3rd-order sequence are of practical significance to tec-tonic analysis, sedimentary environment identification, and other geological researches. Based on the comprehensive analysis of carbon and oxygen isotope trends, paleobathymetry and spectral-frequency of representative well logs, 3rd-order sequences can be divided into 3 types： （a） global sea level （GSL） sequence mainly controlled by GSL change;（b） tectonic sequence mainly controlled by regional tectonic activity;and （c） composite sequence jointly controlled by GSL change and regional tectonic activity. This study aims to identify the controlling factors of 3rd-order sequences and to illustrate a new method for classification of 3rd-order sequences of the middle Permian strata in the Sichuan Basin, China. The middle Permian strata in the Sichuan Basin consist of 3 basin-contrastive 3rd-order sequences, i.e., PSQ1, PSQ2 and PSQ3. Of these, PSQ1 is a GSL sequence while PSQ2 and PSQ3 are composite sequences. The results suggest that the depositional environment was stable during the deposition of PSQ1, but was activated by tectonic activity during the deposition of the middle Permian Maokou Formation.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.S30104)
文摘For the sequences satisfying the recurrence relation of the second order,the generating functions for the products of the powers of these sequences are established.This study was from Carlita and Riordan who began a study on closed form of generating functions for powers of second-order recurrence sequences.This investigation was completed by Stnica.Inspired by the recent work of Istva＇n about the non-closed generating functions of the products of the powers of the second-order sequences,the authors give several extensions of Istva＇n＇s results in this paper.
文摘The boundary value problem of plate bending problem on two_parameter foundation was discussed.Using two series of the high_order fundamental solution sequences, namely, the fundamental solution sequences for the multi_harmonic operator and Laplace operator, applying the multiple reciprocity method(MRM), the MRM boundary integral equation for plate bending problem was constructed. It proves that the boundary integral equation derived from MRM is essentially identical to the conventional boundary integral equation. Hence the convergence analysis of MRM for plate bending problem can be obtained by the error estimation for the conventional boundary integral equation. In addition, this method can extend to the case of more series of the high_order fundamental solution sequences.
基金the Scientific Research Foundation for Returned Overseas Chinese Scholars,State Education Ministrythe Research Foundation of Huazhong University of Science and Technology
文摘A probabilistic progressive failure analyzing method is applied to estimating the reliability of a simply supported laminated composite plate with an initial imperfection under bi-axial compression load. The initial imperfection and the strength parameters are considered as random variables. Ply-level failure probability is evaluated by the first order reliability method (FORM) together with the Tsai-Wu strength criterion and Tan criterion. Current stresses in the laminated structure are calculated by the classical lamination theory with the stiffness modified based on the last step ply failure. Probabilistically dominant ply-level failure sequences leading to overall system failure are identified, based on which the system failure probability is estimated. A numerical example is presented to demonstrate the methodology proposed. Through parameter studies it is shown that the deviation of the initial imperfection and some of the strength parameters largely influence the system reliability.
基金These research results are part of a key international cooperation project carried out during 2003 and 2005 and financially supported by SINOPEC.
文摘In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are preferred by researchers. Under the guidance of the theory of sequence stratigraphy, the findings of this paper indicate that climate is a major factor controlling the formation of the fourth-order sequence, based upon the study of the sequence stratigraphy in the Green River Formation of the Uinta basin in the USA. It also divides the fourth-order sequence in the terrestrial lacustrine basin into two system tracts： the wet （rising） half-cycle and the dry （falling） half- cycle, establishing a new-style fourth-order sequence stratigraphic model for the terrestrial lacustrine basin, that is, the climate-genetic sequence stratigraphic model. As a result, the theory of sequence stratigraphy is greatly enriched.
文摘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.
基金Supported by the PetroChina Science and Technology Major Project(2016E-0601)
文摘Based on isotopic, lithologic and electrical data and logging cycle analysis technique, stratigraphic sequences in the Middle-Upper Cambrian Xixiangchi Group in the Sichuan Basin and its adjacent area are divided, and its sedimentary characteristics and evolution are analyzed. The Xixiangchi Group can be divided into 5 third-order sequences(Sql-Sq5), of which sequences Ⅰ to Ⅲ(Sql-Sq3) are relatively complete, sequences Ⅳ and Ⅴ are denuded in the Late Cambrian because of the Dian-Chuan paleo-uplifts.Third-order sequences of the Xixiangchi Group in this area have the characteristics of thin in the west and thick in the east, showing that the Caledonian paleo-uplift is a synsedimentary paleo-uplift and the paleogeomorphology in the platform is a gentle slope. Sequence Ⅰdevelops high stand systems tract and transgressive systems tract. The other third-order sequences are dominated by highstand systems tracts, and the transgressive systems tracts last shortly in time and are limited in area. The basic features of evaporative-restricted platform of gentle slope type developed continuously in the sedimentary period of the Xixiangchi Group, its sedimentary environment of "high in west and low in east" and the change of micro paleogeomorphology in the platform control the continuous development of sedimentary facies. Open platform is developed only in sequence Ⅰ and sequence Ⅱ, and the inner beach of the platform and the edge beach of the platform are mostly developed in sequence Ⅱ and sequence Ⅲ. It indicates that there are two platform margin zones in the study area,a relatively stable, large-scale platform marginal zone in NE Guizhou-Western Hunan and Hubei, and a moving and small-scale platform marginal zone in North Chongqing-Western Hubei.
基金funded by the University of Macao(file no.MYRG2022-00162-FST and MYRG2019-00136-FST).
文摘The rapid growth of blockchain and Decentralized Finance(DeFi)has introduced new challenges and vulnerabilities that threaten the integrity and efficiency of the ecosystem.This study identifies critical issues such as Transaction Order Dependence(TOD),Blockchain Extractable Value(BEV),and Transaction Importance Diversity(TID),which collectively undermine the fairness and security of DeFi systems.BEV-related activities,including sandwich attacks,liquidations,transaction replay etc.have emerged as significant threats,collectively generating$540.54 million in losses over 32 months across 11,289 addresses,involving 49,691 cryptocurrencies and 60,830 on-chain markets.These attacks exploit transaction mechanics to manipulate asset prices and extract value at the expense of other participants,with sandwich attacks being particularly impactful.Additionally,the growing adoption of blockchain in traditional finance highlights the challenge of TID,wherein high transaction volumes can strain systems and compromise time-sensitive operations.To address these pressing issues,we propose a novel Distributed Transaction Sequencing Strategy(DTSS)that integrates forking mechanisms with an Analytic Hierarchy Process(AHP)to enforce fair and transparent transaction ordering in a decentralized manner.Our approach is further enhanced by an optimization framework and the introduction of a Normalized Allocation Disparity Metric(NADM)that ensures optimal parameter selection for transaction prioritization.Experimental evaluations demonstrated that the DTSS effectively mitigated BEV risks,enhanced transaction fairness,and significantly improved the security and transparency of DeFi ecosystems.
基金Supported by China National Key R&D Program Project of the 15th Five-Year Plan(2025ZD1402703).
文摘Under the guidance of the whole petroleum system theory,using seismic,drilling and laboratory analysis data,and combined with the practical achievements of oil and gas exploration,the distribution patterns of different types of natural gas in the deep-water area of the Qiongdongnan Basin of China were systematically reviewed,the orderly symbiosis mechanisms and hydrocarbon accumulation processes of diverse gas reservoirs were analyzed,and a composite whole petroleum system model for the deep-water strongly active basins in the northern South China Sea was constructed.In the deep-water area of the Qiongdongnan Basin,there are three sets of source rocks,namely the Eocene,the Oligocene,and the upper Miocene-Quaternary,and three whole petroleum systems can be accordingly classified.The source rocks have the characteristics of multilayers,multiple types,and multiple hydrocarbon generation centers.The Eocene lacustrine source rocks,Oligocene marine and continental dual-origin source rocks,and upper Miocene-Quaternary marine source rocks form multiple hydrocarbon generation centers,which are orderly distributed from east to west.The reservoirs are characterized by multiple geological ages,multiple rock types,and multiple hydrodynamic influences,and exist as a reservoir composite superposition pattern with basement buried hill-lower traction flow sandbody-upper gravity flow sandbody vertically in the deep-water area.Fluid activities within the basin are controlled by free dynamic fields,confined dynamic fields,and bound dynamic fields.The natural gas in the whole petroleum system presents an orderly distribution of shale gas(speculated)-tight gas-conventional gas-ultra-shallow gas-hydrate from bottom to top.The research results have verified the adaptability of the whole petroleum system theory in the deep-water area of the Qiongdongnan Basin,providing a theoretical support for the exploration of complex oil and gas resources in the deep-water area,and are expected to effectively guide the distribution prediction and exploration of different types of petroleum resources in deep-water areas.
