In this article,we investigate the spectral properties of a class of neutron transport operators involving elastic and inelastic collision operators introduced by Larsen and Zweifel[1].Our analysis is manly focused on...In this article,we investigate the spectral properties of a class of neutron transport operators involving elastic and inelastic collision operators introduced by Larsen and Zweifel[1].Our analysis is manly focused on the description of the asymptotic spectrum which is very useful in the study of the properties of the solution to Cauchy problem governed by such operators(when it exists).The last section of this work is devoted to the properties of the leading eigenvalue(when it exists).So,we discuss the irreducibility of the semigroups generated by these operators.We close this section by discussing the strict monotonicity of the leading eigenvalue with respect to the parameters of the operator.展开更多
Fine round gravel soil is widely employed in the subgrade of high and thawing. The lower the fines content in fine round gravel soil, but compaction difficulty increases. This study is to obtain the speed railways in ...Fine round gravel soil is widely employed in the subgrade of high and thawing. The lower the fines content in fine round gravel soil, but compaction difficulty increases. This study is to obtain the speed railways in cold regions to prevent frost heaving the smaller the quantities of frost heaving and thawing, optimum fines content and limited frost heaving and thawing. The fine round gravel soil filling (FRGSF) used in the Harbin-Qiqihaer Passenger Dedicated Line is taken as the study object. Influence of fines content on optimum water content, maximum dry density and frost heaving properties of FRGSF were studied by means of compaction and frost heaving tests. Results show that the maximum dry density of the FRGSF increases first and then decreases with an increase of fines content, namely there is an optimum fines content for easy compaction. The method of surface-vibratory instrument is fit for coarse-grained soils, and wet state of coarse-grained soil is in favor of compaction. Considering the relationship of fines content with maximum dry density and the frost heaving ratio of FRGSF, the fines content should be limited to within the range of 9%-10%, so that the frost heaving ratio is less than 1%, and the FRGSF is easily compacted. Water supply is proved to be an important factor influencing the amount of frost heaving of FRGSF. We also conclude that in the field, it is imperative to control waterproofing and drainage measures.展开更多
Based on a characterization of upper semi-Fredholm operators due to A.Lebow and M.Schechter,we introduce and investigate a new quantity characterizing upper semi-Fredholm operators.This quantity and several well-known...Based on a characterization of upper semi-Fredholm operators due to A.Lebow and M.Schechter,we introduce and investigate a new quantity characterizing upper semi-Fredholm operators.This quantity and several well-known quantities are used to characterize bounded compact approximation property.Similarly,a new quantity characterizing lower semi-Fredholm operators is introduced,investigated and used to characterize the bounded compact approximation property for dual spaces.展开更多
In this paper, the notion of the bounded compact approximation property (BCAP) of a pair [Banach space and its subspace] is used to prove that if X is a closed subspace of Eoo with the BCAP, then L∞/X has the BCAP....In this paper, the notion of the bounded compact approximation property (BCAP) of a pair [Banach space and its subspace] is used to prove that if X is a closed subspace of Eoo with the BCAP, then L∞/X has the BCAP. We also show that X* has the A-BCAP with conjugate operators if and only if the pair (X, Y) has the A-BCAP for each finite codimensional subspace Y C X. Let M be a closed subspace of X such that M~ is complemented in X*. If X has the (bounded) approximation property of order p, then M has the (bounded) approximation property of order p.展开更多
文摘In this article,we investigate the spectral properties of a class of neutron transport operators involving elastic and inelastic collision operators introduced by Larsen and Zweifel[1].Our analysis is manly focused on the description of the asymptotic spectrum which is very useful in the study of the properties of the solution to Cauchy problem governed by such operators(when it exists).The last section of this work is devoted to the properties of the leading eigenvalue(when it exists).So,we discuss the irreducibility of the semigroups generated by these operators.We close this section by discussing the strict monotonicity of the leading eigenvalue with respect to the parameters of the operator.
基金funded by the National Key Technology Support Program of China under Grant No. 2012BAG05B00the National Natural Science Foundation (NSFC) of China under Grant No. 51208320 and No. 51171281
文摘Fine round gravel soil is widely employed in the subgrade of high and thawing. The lower the fines content in fine round gravel soil, but compaction difficulty increases. This study is to obtain the speed railways in cold regions to prevent frost heaving the smaller the quantities of frost heaving and thawing, optimum fines content and limited frost heaving and thawing. The fine round gravel soil filling (FRGSF) used in the Harbin-Qiqihaer Passenger Dedicated Line is taken as the study object. Influence of fines content on optimum water content, maximum dry density and frost heaving properties of FRGSF were studied by means of compaction and frost heaving tests. Results show that the maximum dry density of the FRGSF increases first and then decreases with an increase of fines content, namely there is an optimum fines content for easy compaction. The method of surface-vibratory instrument is fit for coarse-grained soils, and wet state of coarse-grained soil is in favor of compaction. Considering the relationship of fines content with maximum dry density and the frost heaving ratio of FRGSF, the fines content should be limited to within the range of 9%-10%, so that the frost heaving ratio is less than 1%, and the FRGSF is easily compacted. Water supply is proved to be an important factor influencing the amount of frost heaving of FRGSF. We also conclude that in the field, it is imperative to control waterproofing and drainage measures.
基金supported by the National Natural Science Foundation of China(Grant No.11971403)the Natural Science Foundation of Fujian Province of China(Grant No.2019J01024)。
文摘Based on a characterization of upper semi-Fredholm operators due to A.Lebow and M.Schechter,we introduce and investigate a new quantity characterizing upper semi-Fredholm operators.This quantity and several well-known quantities are used to characterize bounded compact approximation property.Similarly,a new quantity characterizing lower semi-Fredholm operators is introduced,investigated and used to characterize the bounded compact approximation property for dual spaces.
基金supported by National Natural Science Foundation of China(Grant Nos.10526034 and 10701063)the Fundamental Research Funds for the Central Universities(Grant No.2011121039)supported by NSF(Grant Nos.DMS-0800061 and DMS-1068838)
文摘In this paper, the notion of the bounded compact approximation property (BCAP) of a pair [Banach space and its subspace] is used to prove that if X is a closed subspace of Eoo with the BCAP, then L∞/X has the BCAP. We also show that X* has the A-BCAP with conjugate operators if and only if the pair (X, Y) has the A-BCAP for each finite codimensional subspace Y C X. Let M be a closed subspace of X such that M~ is complemented in X*. If X has the (bounded) approximation property of order p, then M has the (bounded) approximation property of order p.