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Form Invariance and Lie Symmetries of the Rotational Relativistic Birkhoff System

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Chinese Physics Letters 2002年第4期19卷 449-451页

作者：罗绍凯 InstituteofMathematicalMechanicsandMathematicalPhysics ChangshaUniversityChangsha410003

For a rotational relativistic Birkhoff system, the relation between the form invariance and the Lie symmetries are given under infinitesimal transformations of groups. If the infinitesimal transformation generators ξ0 and ξμ satisfy the conditions of the form invariance, and the determining equation of Lie symmetries holds, the form invariance leads to a Lie symmetry of the system. Furthermore, if the infinitesimal transformations generators ξ0 and ξμ satisfy the conditions of the form invariance and the determining equation of Lie symmetry holds, and if there is a gauge function G satisfying the structure equation of Lie symmetry, then the form invariance will lead to the Lie symmetrical conserved quantity of the system. An example is given to illustrate the application of the results.

关键词： Algebra

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基于人际传播的图书馆员服务能力培养研究

情报资料工作 2010年第5期31卷 83-85页

作者：刘海萍阳海燕符勤长沙学院图书馆长沙410003

文章论述了人际传播与图书馆馆员服务能力的关系,指出图书馆员的服务能力实际上是一个人际传播系统行为,探讨了培养馆员服务能力的知识体系的构建。

关键词：人际传播图书馆员服务能力

Invariant subspaces for sequentially subdecomposable operators

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Science China Mathematics 2003年第4期46卷 433-439页

作者：刘明学 Institute of Mathematics Changsha UniversityChangsha 410003 China

In this paper, using Brown technique, we prove the Mohebi-Radjabalipour Conjecture by strengthening a slight thickness condition of the spectrum, and obtain some invariant subspace theorems. Our result contains an imp... 详细信息

关键词： Banach space, sequentially subdecomposable operators, invariant subspace.

Lattice Thermal Conductivity of MgSiO_(3) Perovskite and Post-Perovskite under Lower Mantle Conditions Calculated by Deep Potential Molecular Dynamics

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Chinese Physics Letters 2022年第11期39卷 42-47页

作者： Fenghu Yang Qiyu Zeng Bo Chen Dongdong Kang Shen Zhang Jianhua Wu Xiaoxiang Yu Jiayu Dai Department of Physics National University of Defense TechnologyChangsha 410003China

Lattice thermal conductivity(κlat)of MgSiO_(3) perovskite and post-perovskite is an important parameter for the thermal dynamics in the ***,we develop a deep potential of density functional theory quality under entire thermodynamic conditions in the lower mantle,and calculate theκlatby the Green-Kubo *** potential molecular dynamics captures full-order anharmonicity and considers ill-defined phonons in low-κlatmaterials ignored in the phonon gas ***κlatshows negative temperature dependence and positive linear pressure ***,theκlatundergos an increase at the phase boundary from perovskite to *** demonstrate that,along the geotherm,theκlatincreases by 18.2% at the phase *** results would be helpful for evaluating Earth’s thermal dynamics and improving the Earth model.

关键词： Lattice perovskite Deep

Form Invariance and Noether Symmetries of Rotational Relativistic Birkhoff Systems

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Communications in Theoretical Physics 2002年第9期37卷 257-260页

作者： LUOShao－Kai InstituteofMathematicalMechanicsandMathematicalPhysics ChangshaUniversityChangsha410003China

Under the infinitesimal transformations of groups, a form invariance of rotational relativistic Birkhoff systems is studied and the definition and criteria are given. In view of the invariance of rotational relativistic Pfaff Birkhoff D'Alembert principle under the infinitesimal transformations of groups, the theory of Noether symmetries of rotational relativistic Birkhoff systems are constructed. The relation between the form invariance and the Noether symmetries is studied, and the conserved quantities of rotational relativistic Birkhoff systems are obtained.

关键词： rotational relativity Birkhoff system form invariance Noether symmetry conserved quantity

First Integrals and Integral Invariants of Relativistic Birkhoffian Systems

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Communications in Theoretical Physics 2003年第2X期40卷 133-136页

作者： LUOShao-Kai InstituteofMathematicalMechanicsandMathematicalPhysics ChangshaUniversityChangsha410003China

For a relativistic Birkhoflan system, the first integrals and the construction of integral invariants are studied. Firstly, the cyclic integrals and the generalized energy integral of the system are found by using the perfect differential method. Secondly, the equations of nonsimultaneous variation of the system are established by using the relation between the simultaneous variation and the nonsimultaneous variation. Thirdly, the relation between the first integral and the integral invariant of the system is studied, and it is proved that, using a t^rst integral, we can construct an integral invarlant of the system. Finally, the relation between the relativistic Birkhoflan dynamics and the relativistic Hamilton;an dynamics is discussed, and the first integrals and the integral invariants of the relativistic Hamiltonian system are obtained. Two examples are given to illustrate the application of the results.

关键词：相对论 Birkhoffian系统 Hamiltonian系统初积分积分不变式哈密顿系统

A Machine Learning Framework with Feature Selection for Floorplan Acceleration in IC Physical Design

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Journal of Computer Science & Technology 2020年第2期35卷 468-474页

作者： Shu-Zheng Zhang Zhen-Yu Zhao Chao-Chao Feng Lei Wang College of Computer Science and Technology National University of Defense TechnologyChangsha 410003China

Floorplan is an important process whose quality determines the timing closure in integrated circuit(IC)physical *** generating a floorplan with satisfying timing result is time-consuming because much time is spent on the generation-evaluation *** machine learning to the floorplan stage is a potential method to accelerate the floorplan ***,there exist two challenges which are selecting proper features and achieving a satisfying model *** this paper,we propose a machine learning framework for floorplan acceleration with feature selection and model stacking to cope with the challenges,targeting to reduce time and effort in integrated circuit physical ***,the proposed framework supports predicting post-route slack of static random-access memory(SRAM)in the early floorplan ***,we introduce a feature selection method to rank and select important *** both feature importance and model accuracy,we reduce the number of features from 27 to 15(44%reduction),which can simplify the dataset and help educate novice ***,we build a stacking model by combining different kinds of models to improve *** 28 nm technology,we achieve the mean absolute error of slacks less than 23.03 ps and effectively accelerate the floorplan process by reducing evaluation time from 8 hours to less than 60 *** on our proposed framework,we can do design space exploration for thousands of locations of SRAM instances in few seconds,much more quickly than the traditional *** practical application,we improve the slacks of SRAMs more than 75.5 ps(177%improvement)on average than the initial design.

关键词： physical design machine learning feature selection design space exploration

Requirements ranking based on crowd-sourcing high-end product USs

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Journal of Systems Engineering and Electronics 2024年第1期35卷 94-104页

作者： MA Yufeng DOU Yajie XU Xiangqian JIA Qingyang TAN Yuejin College of Systems Engineering National University of Defense TechnologyChangsha 410003China

Based on the characteristics of high-end products,crowd-sourcing user stories can be seen as an effective means of gathering requirements,involving a large user base and generating a substantial amount of unstructured *** key challenge lies in transforming abstract user needs into specific ones,requiring integration and ***,we propose a topic mining-based approach to categorize,summarize,and rank product requirements from user ***,after determining the number of story categories based on py LDAvis,we initially classify“I want to”phrases within user ***,classic topic models are applied to each category to generate their names,defining each post-classification user story category as a ***,a weighted ranking function is devised to calculate the importance of each ***,we validate the effectiveness and feasibility of the proposed method using 2966 crowd-sourced user stories related to smart home systems.

关键词： high-end product complex system crowd-sourcing user stories topic mining requirements ranking

SYNTHESIS OF THE COPOLYMERS OF p-DIETHYNYLBENZENE WITH OTHER ACETYLENIC DERIVATIVE S INITIATED BY (Ph_3P)_2 PdCl_2

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Chinese Journal of Polymer Science 1993年第1期11卷 38-45页

作者：李银奎陈朝辉 Department of Materials Science and Applied Chemistry Changsha Institute of Technology Changsha 410003

The copolymerization of p-diethynylbenzene (PDEB) with phenylacetylene (PhA), 4, 4'-diethynylbiphenyl (DEBP)or m-diethynylbenzene (MDEB) are studied by varying mole ratios of monomers. When the mole ratios of PDEB/PhA are less or equal to 1/5, the copolymers are soluble and fusible, but the other copolymers are insoluble and infusible. The results show that the good solvent of cross-linked copolymers is benzene and their solubility parameter is 9.15 cal^(0.5).cm(-1.5). And their swellability (θ_p), Huggins parameter (χ), density (d_4^(25)) and the average molecular weights between crosslinks (c) are measured. It is found that θp and c of copolymers are greater but d_4^(25) is less than that of respective homopolymers. IR spectra show that the copolymers have transoid configuration and small number of unreacted ethynyl groups exist in the copolymers. The mechanism about the polymerization or acetylenic derivatives initiated by (Ph_3P)_2PdCl_2 is discussed.

关键词： p-Diethynylbenzene Phenylacetylene 4 4'-Diethynylbiphenyl m-diethynylbenzene