检索结果-南通市图书馆

Species diversity in rock–paper–scissors game coupling with Levy flight

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第12期22卷 549-554页

作者：王栋庄倩樊瑛狄增如 Department of Basic Science Naval Aeronautical and Astronautical University School of Systems Science and center for Complexity research Beijing Normal University

The rock–paper–scissors （RPS） game is a nice model to study the biodiversity in an ecosystem. However, in the previous studies only the nearest-neighbor interaction among the species was considered. In this paper, taking the long-range migration into account, the effects of the interplay between nearest-neighbor-interaction and long-range-interaction given by Levy flight with distance distribution lh （-3 ≤ h 〈-1） in the spatial RPS game are investigated. Taking the probability, exchange rate, and power-law exponent of Levy flight as parameters, the coexistence conditions of three species are given. The critical curves for stable coexistence of three species in the parameter space are presented. It is also found that Levy flight has interesting effects on the final spatiotemporal pattern of the system. The results reveal that the long-range-interaction given by Levy flight exhibits pronounced effects on biodiversity of the ecosystem.

关键词： RPS game Levy flight biodiversity spatial pattern

Adsorption of Ce(Ⅳ) Anionic Nitrato Complexes onto Anion Exchangers and Its Application for Ce(Ⅳ) Separation from Rare Earths(Ⅲ)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2006年第4期24卷 385-391页

作者： Ludek Jelinek Mikio Kumagai Nuclear Chemistry and Chemical Engineering center Institute of Research and Innovation1201 Takada Kashiwa 277-0861 Chiba-prefecture Japan

Ce （Ⅳ） nitrato complexes were adsorbed on two anion exchangers based on polyvinyl pyridine （PVP） and quatemized PVP incorporated into porous silica matrix. The effect of nitric acid concentration （0.5～6 mol·L^-1） and temperature （278 ～318 K） on Ce（ Ⅳ ） sorption efficiency was investigated. Sorption increased with increasing nitric acid concentration, indicating that [Ce（NO3）6]^2- complex is the main adsorbed Ce（Ⅳ） species. Oxidation of sorbents by adsorbed Ce （ Ⅳ ） species resulting in Ce （ Ⅲ ） release to the solution was observed. Pyridine based anion exchangers exhibited higher oxidation stability compared to the commercial strong base anion exchanger. Ce（ Ⅳ ） reduction was temperature dependent and obeyed pseudo-first-order reaction kinetics. Column separation of Ce （ Ⅳ ） from La （ Ⅲ ） and Y （ Ⅲ ） was carried out from 6 mol·L^-1 nitric acid with PVP based anion exchanger. Reasonable Ce （Ⅳ） breakthrough capacity （0.7 mol·kg^-1 PVP） was achieved. No remarkable decrease of capacity was observed within 3 consequent runs. In contrast, Ce （Ⅲ） leakage due to reduction decreased and breakthrough capacity slightly increased. This effect was more pronounced with increasing temperature. Regeneration with 0.1 mol·L^- 1 nitric acid was successful （recovery 100% ± 4% ） and Ce solution of high purity （〉 99.97% ） with respect to La and Y content was gained.

关键词： ion exchange tetravalent cerium separation rare earths

Influence of reaction piles on test pile response in a static load test

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第3期14卷 198-205页

作者： Qian-qing ZHANG Shu-cai LI Zhong-miao ZHANG Geotechnical and Structural Engineering research center Shandong University MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University

This work presents a new analytical method to analyze the influence of reaction piles on the test pile response in a static load *** our method,the interactive effect between soil and pile is simulated using independent springs and the shear displacement method is adopted to analyze the influence of reaction piles on test pile ***,the influence of the sheltering effect between reaction piles and test pile on the test pile response is taken into *** cases are analyzed to verify the rationality and efficiency of the present *** method can be easily extended to a nonlinear response of an influenced test pile embedded in a multilayered soil,and the validity is also demonstrated using centrifuge model tests and a computer program presented in the *** present analyses indicate that the proposed method will lead to an underestimation of the test pile settlement in a static load test if the influence of the presence of reaction piles on the test pile response is neglected.

关键词： Test pile Reaction pile Shear displacement method Sheltering effect Multilayered soil

Entanglement concentration with strong projective measurement in an optomechanical system

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2015年第5期58卷 70-75页

作者： MAIMAITI Wulayimu LI Zhe CHESI Stefano WANG YingDan State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing Computational Science research center

In this work, we study an entanglement concentration scheme in a 3-mode optomechanical system. The scheme is based on phonon counting measurements, which can be performed through photon counting of an auxiliary cavity connected to the mechanical resonator. The amount of entanglement between the two cavity output modes is found to increase logarithmically with the number of detected phonons(photons). Such an entanglement concentration scheme is deterministic since, independently of the number of detected phonons(photons), the measurement always leads to an increase in output entanglement. Besides numerical simulations,we provide analytical results and physical insight for the improved entanglement and the concentration efficiency.

关键词： optomechanics entanglement concentration quantum measurement optomechanical entanglement

Enhancing stationary entanglement between two optomechanical oscillators by Coulomb interaction with Kerr medium

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第12期30卷 406-412页

作者： Tian-Le Yang Chen-Long Zhu Sheng Liu Ye-Jun Xu International research center of Quantum Information and Photoelectric Information School of Mechanical and Electronic EngineeringChizhou UniversityChizhou 247000China

We theoretically study the stationary entanglement of two charged nanomechanical oscillators coupling via Coulomb interaction in an optomechanical system with an additional Kerr *** show that the degree of entanglement between two nanomechanical oscillators is suppressed by Kerr interaction due to photon blockade and enhanced by Coulomb coupling *** also show other parameters for adjusting and obtaining entanglement,such as the driving power and the frequencies of the two oscillators,and the entanglement is robust against *** study proves a way for adjusting stationary entanglement between two optomechanical oscillators by Coulomb interaction and Kerr medium.

关键词： entanglement Kerr interaction Coulomb interaction optomechanics

UPF based autonomous navigation scheme for deep space probe

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2008年第3期19卷 529-536页

作者： Li Peng Cui Hutao Cui Pingyuan Deep Space Exploration research center Harbin Inst. of Technology Harbin 150080 P. R. China

The autonomous "celestial navigation scheme" for deep space probe departing from the earth and the autonomous "optical navigation scheme" for encountering object celestial body are presented. Then, aiming at the conditions that large initial estimation errors and non-Gaussian distribution of state or measurement errors may exist in orbit determination process of the two phases, UPF (unscented particle filter) is introduced into the navigation schemes. By tackling nonlinear and non-Gaussian problems, UPF overcomes the accuracy influence brought by the traditional EKF (extended Kalman filter), UKF (unscented Kalman filter), and PF (particle filter) schemes in approximate treatment to nonlinear and non-Gaussian state model and measurement model. The numerical simulations demonstrate the feasibility and higher accuracy of the UPF navigation scheme.

关键词： control and navigation technology of aircraft nonlinear and non-Gaussian unscented particle filter autonomous orbit determination celestial navigation optical navigation.

Effect of rare earth alloying on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel at 650 ℃

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2016年第4期34卷 447-452页

作者：陈雷龙红军刘鑫刚金淼马筱聪 National Engineering research center for Equipment and Technology of Cold Strip Rolling Yanshan University School of Mechanical Engineering Yanshan University

The effect of rare earth（RE） on creep rupture of economical 21Cr-11Ni-N heat-resistant austenitic steel was investigated at 650 °C under different stress levels. It was found that RE could increase the time to creep rupture, especially at long-term creep duration. The logarithm of the time to creep rupture（lgtr） was a linear function of the applied stress（σ）. RE addition was favorable to generating a high fraction of low-coincidence site lattice（CSL） boundaries which was a possible cause for improving the creep rupture resistance. The fracture surface of RE-added steel exhibited less intergranular cracks suggesting the alteration on the nature of grain boundaries due to the presence of RE. RE addition changed the morphology of the intergranular chromium carbides from continuous network shape to fragmentary distribution which was another cause for longer creep duration. These results strongly suggested that the effect of RE alloying played a crucial role in improving the creep rupture resistance.

关键词： heat-resistant austenitic steel rare earths alloying creep rupture

Geophysical criterion of pre-outburst coal outsqueezing from the face space into the working

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第3期29卷 499-506页

作者： Alexander Shadrin Yuliya Diyuk Federal State Budget Scientific Institution The Federal Research Center of Coal and Coal Chemistry of Siberian Branch of the Russian Academy of Sciences

The initial process of coal and gas sudden outburst is studied in the article when under the influence of rock and gas pressure the part of a coal seam layer(a coal section)is squeezed out from the mouth of the future outburst cavity in a jump-like manner into the ***-mechanical criterion for a part of a coal seam layer outsqueezing in the form of the relation of active(squeezing out)and passive(preventing the outsqueezing)forces is defined in the *** on it,the geophysical criterion is defined by expressing basic physical parameters through geo-physical ones:the current stress is defined by spectral-acoustic method through the ratio of high frequency and low-frequency components of an acoustic signal,which is generated into a face working space by the mining equipment operating in the face;in-situ gas pressure is defined by gas analytical method by the concentration of methane in the atmosphere of the working;the strength of the most broken coal layer is defined by a strength measuring device(a device for measuring the depth of a steal cone punched into the coal by a spring mechanism).This paper studies the influence of acoustic,strength and filtrating and collecting properties of a face working space on the limit value of an obtained geophysical criterion of pre-outburst squeezing of a coal‘‘plug”out of the mouth of the future outburst cavity into the working.

关键词： Block-like structure Criterion of a coal section outsqueezing Spectral-acoustic method Stress condition Coal strength property In-situ gas pressure Aero and gas control equipment Methane concentration

The ternary Ni–Al–Co embedded-atom-method potential for γ/γ Ni-based single-crystal superalloys: Construction and application

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第3期23卷 224-231页

作者：杜俊平王崇愚于涛 Central Iron and Steel research Institute Department of Physics Tsinghua University The International center for Materials Physics Chinese Academy of Sciences

An Ni-AI-Co system embedded-atom-method potential is constructed for the γ（Ni）/γ＇（Ni3A1） superalloy based on experiments and first-principles calculations. The stacking fault energies （SFEs） of the Ni（Co, A1） random solid solutions are calculated as a function of the concentrations of Co and A1. The calculated SFEs decrease with increasing concentrations of Co and A1, which is consistent with the experimental results. The embedding energy term in the present potential has an important influence on the SFEs of the random solid solutions. The cross-slip processes of a screw dislocation in homogenous Ni（Co） solid solutions are simulated using the present potential and the nudged elastic band method. The cross-slip activation energies increase with increasing Co concentration, which implies that the creep resistance of γ（Ni） may be improved by the addition of Co.

关键词： interatomic interaction potential embedded-atom method Ni-based single-crystal superalloys