The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce t...The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.展开更多
After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of...After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of triaxial extension tests were conducted on sandstone under confining pressures of 10,30,50 and 70 MPa.Elastic energy and dissipated energy were separated by single unloading,the input energy u_(t),elastic energy u_(e),and dissipated energy u_(d)at different unloading stress levels were calculated by the integrating stress−strain curves.The results show that tensile cracks dominate fracture under lower confining pressure(10 MPa),and shear cracks play an increasingly important role in fracture as confining pressure increases(30,50 and 70 MPa).Based on the phenomenon that u_(e)and u_(d)increase linearly with increasing u_(t),a possible energy distribution mechanism of fracture mode transition under triaxial extension was proposed.In addition,it was found that peak energy storage capacity is more sensitive to confining pressure compared to elastic energy conversion capacity.展开更多
Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challeng...Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challenging task. A multidatabase common data model is firstly introduced based on XML, named XML-based Integration Data Model (XIDM), which is suitable for integrating different types of schemas. Then an approach of schema mappings based on XIDM in multidatabase systems has been presented. The mappings include global mappings, dealing with horizontal and vertical partitioning between global schemas and export schemas, and local mappings, processing the transformation between export schemas and local schemas. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama system are also discussed. The implementation results demonstrate that the XIDM is an efficient model for managing multiple heterogeneous data sources and the approaches of schema mapping based on XIDM behave very well when integrating relational, object-oriented database systems and other file systems.展开更多
通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discov...通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discovery Studio 4.1分析其蛋白结构,以对硝基苯-α-D-葡萄糖吡喃苷(pNPG)为底物,建立并确定酶活反应条件,并进行纯化、酶学性质分析;将密码子优化后序列在CICC1346中实现分泌表达,利用淀粉进行共发酵实验。结果显示:重组酶突变后相对野生型蛋白结构无影响。SDS-PAGE分析重组重组酶大小约为70 kDa;优化后最高酶活达到0.69 U/m L,重组酶最适pH为6.5,在pH4.5.0~7.0维持90%以上的酶活;最适温度为40℃,在30~40℃维持接近100%的酶活;受Cu^(2+)和Mn^(2+)严格抑制;寡聚-1,6-葡萄糖苷酶与α-淀粉酶及糖化酶协同利用淀粉产乙醇,提高淀粉水解效率。这是首次报道黄曲霉的寡聚-1,6-葡萄糖苷酶基因在酿酒酵母整合型分泌表达。展开更多
基金National Natural Science Foundation of China(12161013)Research Projects of Guizhou University of Commerce in 2024。
文摘The modifiedλ-differential Lie-Yamaguti algebras are considered,in which a modifiedλ-differential Lie-Yamaguti algebra consisting of a Lie-Yamaguti algebra and a modifiedλ-differential operator.First we introduce the representation of modifiedλ-differential Lie-Yamaguti algebras.Furthermore,we establish the cohomology of a modifiedλ-differential Lie-Yamaguti algebra with coefficients in a representation.Finally,we investigate the one-parameter formal deformations and Abelian extensions of modifiedλ-differential Lie-Yamaguti algebras using the second cohomology group.
基金Project(52074352)supported by the National Natural Science Foundation of ChinaProject(2023JJ30680)supported by the National Science and Technology Major Project of China。
文摘After excavation,some of the surrounding rock mass is in a state of triaxial extension,exhibiting tensile or shear fracture modes.To study the energy mechanism of tensile fracture turning to shear fracture,a series of triaxial extension tests were conducted on sandstone under confining pressures of 10,30,50 and 70 MPa.Elastic energy and dissipated energy were separated by single unloading,the input energy u_(t),elastic energy u_(e),and dissipated energy u_(d)at different unloading stress levels were calculated by the integrating stress−strain curves.The results show that tensile cracks dominate fracture under lower confining pressure(10 MPa),and shear cracks play an increasingly important role in fracture as confining pressure increases(30,50 and 70 MPa).Based on the phenomenon that u_(e)and u_(d)increase linearly with increasing u_(t),a possible energy distribution mechanism of fracture mode transition under triaxial extension was proposed.In addition,it was found that peak energy storage capacity is more sensitive to confining pressure compared to elastic energy conversion capacity.
文摘Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challenging task. A multidatabase common data model is firstly introduced based on XML, named XML-based Integration Data Model (XIDM), which is suitable for integrating different types of schemas. Then an approach of schema mappings based on XIDM in multidatabase systems has been presented. The mappings include global mappings, dealing with horizontal and vertical partitioning between global schemas and export schemas, and local mappings, processing the transformation between export schemas and local schemas. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama system are also discussed. The implementation results demonstrate that the XIDM is an efficient model for managing multiple heterogeneous data sources and the approaches of schema mapping based on XIDM behave very well when integrating relational, object-oriented database systems and other file systems.
文摘通过重叠延伸PCR(gene splicing by overlap extension,SOE-PCR)扩增黄曲霉寡聚-1,6-葡萄糖苷酶基因和酿酒酵母α-信号肽序列,定向重组到整合型表达载体pδRCMB中,并在CICC1346中实现分泌表达;然后通过同源建模、利用分子模拟软件Discovery Studio 4.1分析其蛋白结构,以对硝基苯-α-D-葡萄糖吡喃苷(pNPG)为底物,建立并确定酶活反应条件,并进行纯化、酶学性质分析;将密码子优化后序列在CICC1346中实现分泌表达,利用淀粉进行共发酵实验。结果显示:重组酶突变后相对野生型蛋白结构无影响。SDS-PAGE分析重组重组酶大小约为70 kDa;优化后最高酶活达到0.69 U/m L,重组酶最适pH为6.5,在pH4.5.0~7.0维持90%以上的酶活;最适温度为40℃,在30~40℃维持接近100%的酶活;受Cu^(2+)和Mn^(2+)严格抑制;寡聚-1,6-葡萄糖苷酶与α-淀粉酶及糖化酶协同利用淀粉产乙醇,提高淀粉水解效率。这是首次报道黄曲霉的寡聚-1,6-葡萄糖苷酶基因在酿酒酵母整合型分泌表达。
