This paper presents a new graph-based single-copy routmg method m delay tolerant networks （DTN）. With time goes on in the networks, a DTN connectivity graph is constituted with mobility of nodes and communication, a...This paper presents a new graph-based single-copy routmg method m delay tolerant networks （DTN）. With time goes on in the networks, a DTN connectivity graph is constituted with mobility of nodes and communication, and a corresponding greedy tree is obtained using a greedy algorithm in DTN connectivity graph. While there are some bad nodes such as disabled nodes or selfish nodes in delay tolerant networks, the nodes can choose the next p^oper intermediate node to transmit the mes- sage by comparing the location of neighboring nodes in the greedy tree. The single-copy routing method is very appropriate for energy-constrained, storage-constrained and bandwidth-constrained applications such as mobile wireless DTN networks. We show that delivery ratio is increased significantly by using the graph-based single-copy routing when bad nodes exist.展开更多
In this paper,we have given a fixed point theorem for mapping sequence and mapping pair on nonarchimedean Mengen Probabilistic Metric space.A special case of its inference is an extension of results of reference [5-6].
Cyclin-dependent kinase 2 (CDK2) is a key macromolecule in cell cycle regulation. In cancer cells, CDK2 is often overexpressed and its inhibition is an effective therapy of many cancers including breast carcinomas, le...Cyclin-dependent kinase 2 (CDK2) is a key macromolecule in cell cycle regulation. In cancer cells, CDK2 is often overexpressed and its inhibition is an effective therapy of many cancers including breast carcinomas, leukemia, and lymphomas. Quantitative characterization of the interactions between CDK2 and its inhibitors at atomic level may provide a deep understanding of protein-inhibitor interactions and clues for more effective drug discovery. In this study, we have used the computational alanine scanning approach in combination with an efficient interaction entropy method to study the microscopic mechanism of binding between CDK2 and its 13 inhibitors. The total binding free energy from the method shows a correlation of 0.76?0.83 with the experimental values. The free energy component reveals two binding mode in the 13 complexes, namely van der Waals dominant, and electrostatic dominant. Decomposition of the total energy to per-residue contribution allows us to identify five hydrophobic residues as hot spots during the binding. Residues that are responsible for determining the strength of the binding were also analyzed.展开更多
A method for spacecraft formation flying (SFF) design and control near libration point orbits was developed by making use of the Floquet theory for periodic orbits. Firstly, the Floquet theory used in libration point ...A method for spacecraft formation flying (SFF) design and control near libration point orbits was developed by making use of the Floquet theory for periodic orbits. Firstly, the Floquet theory used in libration point orbits was introduced and the coefficients of four Floquet periodic modes were proved to be nearly constant when the amplitude in z direction of earth-moon L1 halo orbits is less than 20000 km. On this basis, a configuration design approach to SFF in L1 halo orbits was proposed, and several types of special configurations were obtained with periodic mode 3 and mode 5 or mode 4 and mode 6. Then, in order to control the SFF configuration concisely, those coefficients of the 5 modes (except the stable one) must be kept constant. A stationkeeping method for SFF was developed, which controls 5 Floquet modes simultaneously. Finally, simulations showed that the Floquet-based approach of configuration design and control for SFF is effective, simple and convenient. The research may be of value for deep space explorations.展开更多
The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test cross...The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test crosses, we established an ‘‘all-fish'' growth hormone(GH)transgenic common carp family that exhibits fast growth.In this present study, genome walking, real-time quantitative polymerase chain reaction, and fluorescence in situ hybridization techniques were applied to identify the integration characteristics of the exogenous grass carp GH gene in the transgenic common carp. The exogenous GH genes, in the form of two complete and one incomplete tandem repeats, were found to have integrated into an ATrich region near the end of a chromosome pair. We hypothesize that the high efficiency of exogenous GH gene expression might be due to the low copy number in the genome and the AT-rich integration site.展开更多
The point defects and their related physical properties in L10 FePt are investigated by molecular dynamics simulations based on an analytic bond-order potential. The calculated results agree well with the experimental...The point defects and their related physical properties in L10 FePt are investigated by molecular dynamics simulations based on an analytic bond-order potential. The calculated results agree well with the experimental value, indicating that the analytic bond-order potential is suitable to describe the structural properties and surface energies of the FePt alloy in the L10 phase. However, the calculated vacancy formation energy of an Fe atom is higher than that of a Pt atom, which disagrees with some other previously calculated results. This result indicates that the analytic bond-order potential is unable to describe the related point defect properties. The analytic bond-order potential needs to be modified in order to study these defect properties of an FePt alloy.展开更多
基金Supported by the National High Technology Research and Development Programme of China （No. 2007AA01Z429, 2007AA01Z405 ） and the National Natural Science Foundation of China （No. 60633020, 60702059, 60872041 ）.
文摘This paper presents a new graph-based single-copy routmg method m delay tolerant networks （DTN）. With time goes on in the networks, a DTN connectivity graph is constituted with mobility of nodes and communication, and a corresponding greedy tree is obtained using a greedy algorithm in DTN connectivity graph. While there are some bad nodes such as disabled nodes or selfish nodes in delay tolerant networks, the nodes can choose the next p^oper intermediate node to transmit the mes- sage by comparing the location of neighboring nodes in the greedy tree. The single-copy routing method is very appropriate for energy-constrained, storage-constrained and bandwidth-constrained applications such as mobile wireless DTN networks. We show that delivery ratio is increased significantly by using the graph-based single-copy routing when bad nodes exist.
文摘In this paper,we have given a fixed point theorem for mapping sequence and mapping pair on nonarchimedean Mengen Probabilistic Metric space.A special case of its inference is an extension of results of reference [5-6].
基金supported by National Key R&D Program of China (No.2016YFA0501700)National Natural Science Foundation of China (No.21433004, No.31700646, No.91753103)+1 种基金Innovation Program of Shanghai Municipal Education Commission (201701070005E00020)NYU Global Seed Grant
文摘Cyclin-dependent kinase 2 (CDK2) is a key macromolecule in cell cycle regulation. In cancer cells, CDK2 is often overexpressed and its inhibition is an effective therapy of many cancers including breast carcinomas, leukemia, and lymphomas. Quantitative characterization of the interactions between CDK2 and its inhibitors at atomic level may provide a deep understanding of protein-inhibitor interactions and clues for more effective drug discovery. In this study, we have used the computational alanine scanning approach in combination with an efficient interaction entropy method to study the microscopic mechanism of binding between CDK2 and its 13 inhibitors. The total binding free energy from the method shows a correlation of 0.76?0.83 with the experimental values. The free energy component reveals two binding mode in the 13 complexes, namely van der Waals dominant, and electrostatic dominant. Decomposition of the total energy to per-residue contribution allows us to identify five hydrophobic residues as hot spots during the binding. Residues that are responsible for determining the strength of the binding were also analyzed.
基金supported by the National Natural Science Foundation of China (Grant No. 10702078)the National University of Defense Technology Research Program (Grant No. JC08-01-05)
文摘A method for spacecraft formation flying (SFF) design and control near libration point orbits was developed by making use of the Floquet theory for periodic orbits. Firstly, the Floquet theory used in libration point orbits was introduced and the coefficients of four Floquet periodic modes were proved to be nearly constant when the amplitude in z direction of earth-moon L1 halo orbits is less than 20000 km. On this basis, a configuration design approach to SFF in L1 halo orbits was proposed, and several types of special configurations were obtained with periodic mode 3 and mode 5 or mode 4 and mode 6. Then, in order to control the SFF configuration concisely, those coefficients of the 5 modes (except the stable one) must be kept constant. A stationkeeping method for SFF was developed, which controls 5 Floquet modes simultaneously. Finally, simulations showed that the Floquet-based approach of configuration design and control for SFF is effective, simple and convenient. The research may be of value for deep space explorations.
基金supported by the National High Technology Research and Development Program of China(‘‘863’’Program)(2011AA100404,2011AA100403)the National Natural Science Foundation of China(31325026,31272649)
文摘The genetic stability and expression efficiency of exogenous genes in transgenic animals are closely related to integration site and copy number. In our laboratory, by transgenic manipulation and subsequent test crosses, we established an ‘‘all-fish'' growth hormone(GH)transgenic common carp family that exhibits fast growth.In this present study, genome walking, real-time quantitative polymerase chain reaction, and fluorescence in situ hybridization techniques were applied to identify the integration characteristics of the exogenous grass carp GH gene in the transgenic common carp. The exogenous GH genes, in the form of two complete and one incomplete tandem repeats, were found to have integrated into an ATrich region near the end of a chromosome pair. We hypothesize that the high efficiency of exogenous GH gene expression might be due to the low copy number in the genome and the AT-rich integration site.
基金supported by the National Natural Science Foundation of China (Grant No. 50971011)the Beijing Natural Science Foundation (Grant No. 1102025)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20091102110038)
文摘The point defects and their related physical properties in L10 FePt are investigated by molecular dynamics simulations based on an analytic bond-order potential. The calculated results agree well with the experimental value, indicating that the analytic bond-order potential is suitable to describe the structural properties and surface energies of the FePt alloy in the L10 phase. However, the calculated vacancy formation energy of an Fe atom is higher than that of a Pt atom, which disagrees with some other previously calculated results. This result indicates that the analytic bond-order potential is unable to describe the related point defect properties. The analytic bond-order potential needs to be modified in order to study these defect properties of an FePt alloy.
