In this paper, we study the homotopy category of unbounded complexes of strongly copure projective modules with bounded relative homologies K;（SCP）.We show that the existence of a right recollement of K;（SCP） with...In this paper, we study the homotopy category of unbounded complexes of strongly copure projective modules with bounded relative homologies K;（SCP）.We show that the existence of a right recollement of K;（SCP） with respect to K;（SCP）, K;（SCP） and K;（SCP） has the homotopy category of strongly copure projective acyclic complexes as a triangulated subcategory in some case.展开更多
As rule-based systems (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the o...As rule-based systems (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the obstacles to the adoption of this technology. In the past several years, a vast body of research has been carried out in developing various graphical techniques such as utilizing Petri Nets to analyze structural errors in rule-based systems, which utilize propositional logic. Four typical errors in rule-based systems are redundancy, circularity, incompleteness, and inconsistency. Recently, a DNA-based computing approach to detect these errors has been proposed. That paper presents algorithms which are able to detect structural errors just for special cases. For a rule base, which contains multiple starting nodes and goal nodes, structural errors are not removed correctly by utilizing the algorithms proposed in that paper and algorithms lack generality. In this study algorithms mainly based on Adleman’s operations, which are able to detect structural errors, in any form that they may arise in rule base, are presented. The potential of applying our algorithm is auspicious giving the operational time complexity of O(n*(Max{q, K, z})), in which n is the number of fact clauses;q is the number of rules in the longest inference chain;K is the number of tubes containing antecedents which are comprised of distinct number of starting nodes;and z denotes the maximum number of distinct antecedents comprised of the same number of starting nodes.展开更多
Some questions regarding the analysis of classifiers and classifier constructions are raised in this paper.The classifier,as a mere adjunct adjoining to the head,cannot serve as the head of the noun phrase containing ...Some questions regarding the analysis of classifiers and classifier constructions are raised in this paper.The classifier,as a mere adjunct adjoining to the head,cannot serve as the head of the noun phrase containing it,and as a result,it cannot project as ClP or nP.Under this approach,the DP analysis and the classifier construction theory are further refined.The constituents which precede and follow the classifier are analyzed in terms of their syntactic functions,semantic relations,linear features,feature assignment and syntactic occurrence in order to represent the classifier construction with the X-bar phrase structure theory appropriately and correctly and present a universal approach to classifier constructions in various languages.展开更多
This paper investigates the structural upgrade of China's commodity trade over the past two decades from the perspectives of commodity categories, technical value-added and quality level. Based on the analysis of ...This paper investigates the structural upgrade of China's commodity trade over the past two decades from the perspectives of commodity categories, technical value-added and quality level. Based on the analysis of commodity categories, technical value-added and quality, this paper arrives at the following findings: High technology manufactures accounted for a growing share of China's commodity export, the overall technical level of Chinese exports significantly upgraded, and most of Chinese commodities upgraded from low quality to medium-and high-quality levels. As can be seen from the structure of China's bilateral trade with its five major trading partners, China's exporting goods remained inferior to importing goods in terms of technology and quality despite their quality upgrades.展开更多
In this paper, we consider two kinds of 2-Calabi-Yau triangulated categories with finitely many indecomposable objects up to isomorphisms, called An,t =D^b（KA（2t＋1）（n＋1）-3）/τ^t（n＋1）-1[1], where n,t ≥ 1, a...In this paper, we consider two kinds of 2-Calabi-Yau triangulated categories with finitely many indecomposable objects up to isomorphisms, called An,t =D^b（KA（2t＋1）（n＋1）-3）/τ^t（n＋1）-1[1], where n,t ≥ 1, and Dn,t = Db（KD2t（n＋1））/τ^（n＋1）φ^n, where n,t ≥ 1, and φ is induced by an automorphism of D2t（n＋1） of order 2. Except the categories An,1, they all contain non-zero maximal rigid objects which are not cluster tilting. An,1 contain cluster tilting objects. We define the cluster complex of An,t （resp. Dn,t） by using the geometric description of cluster categories of type A （resp. type D）. We show that there is an isomorphism from the cluster complex of An,t （resp. Dn,t） to the cluster complex of root system of type Bn. In particular, the maximal rigid objects are isomorphic to clusters. This yields a result proved recently by Buan-Palu-Reiten： Let RAn,t, resp. RDn,t, be the full subcategory of An,t, resp. Dn,t, generated by the rigid objects. Then RAn,t≈RAn,1 and TDn,t≈TAn,1 as additive categories, for all t 〉 1.展开更多
发育微生物席或微生物膜的沉积底被形象地称为席底,在席底上由于微生物席的发育使沉积物富黏性而抗水流改造,并在沉积面和沉积层内形成一系列奇形怪状的原生沉积构造,如变余波痕、皱饰构造、微生物席碎片、纺锤状或次圆状收缩裂缝等等,...发育微生物席或微生物膜的沉积底被形象地称为席底,在席底上由于微生物席的发育使沉积物富黏性而抗水流改造,并在沉积面和沉积层内形成一系列奇形怪状的原生沉积构造,如变余波痕、皱饰构造、微生物席碎片、纺锤状或次圆状收缩裂缝等等,这些构造都归为席底构造;与席底相对应,那些不发育微生物席或微生物膜的沉积面则称为混合底,在混合底上单个沉积颗粒受到水流剪切与变形作用的改造而形成诸如正常波痕等原生沉积构造,这些沉积构造则归为混合底构造。席底和席底构造的概念很重要,用来专指微生物沉积作用的产物而区别于混合底和混合底构造。从沉积学概念的演变方面分析,混合底构造就是1964年Pettijohn和Potter所定义的原生沉积构造,他们曾经将其归为4大类并且沿用至今;席底构造也就是微生物形成的(或相关的)原生沉积构造,由于其在形成机理和形态上与Pettijohn和Potter所定义的原生沉积构造存在较大的区别,Noffke 2001年认为其应该具有合适的分类位置,所以就将席底构造归为“第五类原生沉积构造”并纳入Pettijohn和Potter 1964年的原生沉积构造的分类体系之中。从席底构造到第五类原生沉积构造,概念的演变表明了万能的微生物在沉积作用过程中的重要性以及沉积学家对微生物沉积作用认识的深入。这些相关的沉积构造及其所形成的席底,就像叠层石(被当作正生长原生沉积构造)一样在前寒武纪地层之中较为普遍。随着后生动物的大规模出现而造成的寒武纪“农艺革命”(Agronom ic revolution)的开始,显生宙的席底及其相关的席底构造多出现在那些不适宜后生动物居住的地方并大多被混合底及其相关的混合底构造所替代;因此,与微生物相关的原生沉积构造,除熟知的叠层石以外,在席底上发育的一系列原生沉积构造,由于其具有特别的指相意义并有助于古环境重塑而被很自然地归到“第五类原生沉积构造”。该类构造由于其在前寒武纪的普遍性和显生宙的局限分布性,特别是在生物大灭绝事件之后的灾难性泛滥,对于研究地球表层环境的演变具有重要意义。所以说,从席底构造到第五类原生沉积构造,是近年来沉积学发展过程中所出现的较为重要的基本概念。根据这一重要概念,对前寒武纪地层中一些常常被认为是遗迹化石、长期以来存在的“臼齿状构造谜”(Molar-tooth structure en igm a)等奇形怪状的沉积构造的成因以及从前寒武纪到显生宙地层中均有分布的特殊的纹理化构造等,将会得到一些更加合理的认识;另一方面,关于微生物形成的原生沉积构造的研究,对于了解地球表层生物变化与沉积变化之间的复杂关系将会发现更多的新问题而得到进一步的思考与研究。展开更多
文摘In this paper, we study the homotopy category of unbounded complexes of strongly copure projective modules with bounded relative homologies K;（SCP）.We show that the existence of a right recollement of K;（SCP） with respect to K;（SCP）, K;（SCP） and K;（SCP） has the homotopy category of strongly copure projective acyclic complexes as a triangulated subcategory in some case.
文摘As rule-based systems (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the obstacles to the adoption of this technology. In the past several years, a vast body of research has been carried out in developing various graphical techniques such as utilizing Petri Nets to analyze structural errors in rule-based systems, which utilize propositional logic. Four typical errors in rule-based systems are redundancy, circularity, incompleteness, and inconsistency. Recently, a DNA-based computing approach to detect these errors has been proposed. That paper presents algorithms which are able to detect structural errors just for special cases. For a rule base, which contains multiple starting nodes and goal nodes, structural errors are not removed correctly by utilizing the algorithms proposed in that paper and algorithms lack generality. In this study algorithms mainly based on Adleman’s operations, which are able to detect structural errors, in any form that they may arise in rule base, are presented. The potential of applying our algorithm is auspicious giving the operational time complexity of O(n*(Max{q, K, z})), in which n is the number of fact clauses;q is the number of rules in the longest inference chain;K is the number of tubes containing antecedents which are comprised of distinct number of starting nodes;and z denotes the maximum number of distinct antecedents comprised of the same number of starting nodes.
文摘Some questions regarding the analysis of classifiers and classifier constructions are raised in this paper.The classifier,as a mere adjunct adjoining to the head,cannot serve as the head of the noun phrase containing it,and as a result,it cannot project as ClP or nP.Under this approach,the DP analysis and the classifier construction theory are further refined.The constituents which precede and follow the classifier are analyzed in terms of their syntactic functions,semantic relations,linear features,feature assignment and syntactic occurrence in order to represent the classifier construction with the X-bar phrase structure theory appropriately and correctly and present a universal approach to classifier constructions in various languages.
基金supported by Shanghai Municipal Philosophical and Social Science Planning General Program(2017BJL005)
文摘This paper investigates the structural upgrade of China's commodity trade over the past two decades from the perspectives of commodity categories, technical value-added and quality level. Based on the analysis of commodity categories, technical value-added and quality, this paper arrives at the following findings: High technology manufactures accounted for a growing share of China's commodity export, the overall technical level of Chinese exports significantly upgraded, and most of Chinese commodities upgraded from low quality to medium-and high-quality levels. As can be seen from the structure of China's bilateral trade with its five major trading partners, China's exporting goods remained inferior to importing goods in terms of technology and quality despite their quality upgrades.
基金Supported by the NSF of China(Grant No.11671221)
文摘In this paper, we consider two kinds of 2-Calabi-Yau triangulated categories with finitely many indecomposable objects up to isomorphisms, called An,t =D^b（KA（2t＋1）（n＋1）-3）/τ^t（n＋1）-1[1], where n,t ≥ 1, and Dn,t = Db（KD2t（n＋1））/τ^（n＋1）φ^n, where n,t ≥ 1, and φ is induced by an automorphism of D2t（n＋1） of order 2. Except the categories An,1, they all contain non-zero maximal rigid objects which are not cluster tilting. An,1 contain cluster tilting objects. We define the cluster complex of An,t （resp. Dn,t） by using the geometric description of cluster categories of type A （resp. type D）. We show that there is an isomorphism from the cluster complex of An,t （resp. Dn,t） to the cluster complex of root system of type Bn. In particular, the maximal rigid objects are isomorphic to clusters. This yields a result proved recently by Buan-Palu-Reiten： Let RAn,t, resp. RDn,t, be the full subcategory of An,t, resp. Dn,t, generated by the rigid objects. Then RAn,t≈RAn,1 and TDn,t≈TAn,1 as additive categories, for all t 〉 1.
文摘发育微生物席或微生物膜的沉积底被形象地称为席底,在席底上由于微生物席的发育使沉积物富黏性而抗水流改造,并在沉积面和沉积层内形成一系列奇形怪状的原生沉积构造,如变余波痕、皱饰构造、微生物席碎片、纺锤状或次圆状收缩裂缝等等,这些构造都归为席底构造;与席底相对应,那些不发育微生物席或微生物膜的沉积面则称为混合底,在混合底上单个沉积颗粒受到水流剪切与变形作用的改造而形成诸如正常波痕等原生沉积构造,这些沉积构造则归为混合底构造。席底和席底构造的概念很重要,用来专指微生物沉积作用的产物而区别于混合底和混合底构造。从沉积学概念的演变方面分析,混合底构造就是1964年Pettijohn和Potter所定义的原生沉积构造,他们曾经将其归为4大类并且沿用至今;席底构造也就是微生物形成的(或相关的)原生沉积构造,由于其在形成机理和形态上与Pettijohn和Potter所定义的原生沉积构造存在较大的区别,Noffke 2001年认为其应该具有合适的分类位置,所以就将席底构造归为“第五类原生沉积构造”并纳入Pettijohn和Potter 1964年的原生沉积构造的分类体系之中。从席底构造到第五类原生沉积构造,概念的演变表明了万能的微生物在沉积作用过程中的重要性以及沉积学家对微生物沉积作用认识的深入。这些相关的沉积构造及其所形成的席底,就像叠层石(被当作正生长原生沉积构造)一样在前寒武纪地层之中较为普遍。随着后生动物的大规模出现而造成的寒武纪“农艺革命”(Agronom ic revolution)的开始,显生宙的席底及其相关的席底构造多出现在那些不适宜后生动物居住的地方并大多被混合底及其相关的混合底构造所替代;因此,与微生物相关的原生沉积构造,除熟知的叠层石以外,在席底上发育的一系列原生沉积构造,由于其具有特别的指相意义并有助于古环境重塑而被很自然地归到“第五类原生沉积构造”。该类构造由于其在前寒武纪的普遍性和显生宙的局限分布性,特别是在生物大灭绝事件之后的灾难性泛滥,对于研究地球表层环境的演变具有重要意义。所以说,从席底构造到第五类原生沉积构造,是近年来沉积学发展过程中所出现的较为重要的基本概念。根据这一重要概念,对前寒武纪地层中一些常常被认为是遗迹化石、长期以来存在的“臼齿状构造谜”(Molar-tooth structure en igm a)等奇形怪状的沉积构造的成因以及从前寒武纪到显生宙地层中均有分布的特殊的纹理化构造等,将会得到一些更加合理的认识;另一方面,关于微生物形成的原生沉积构造的研究,对于了解地球表层生物变化与沉积变化之间的复杂关系将会发现更多的新问题而得到进一步的思考与研究。
