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Tungsten 2025年第1期 120-136页

作者： Zao-Ming Wu lin He lin-sen Ye Xiao-Feng Yang Jia-Jia Zhang Hong-Bo Lei Institute of Materials China Academy of Engineering Physics

High-density uniform microstructure nanocrystalline W-10wt.% Cr-5wt.% Y（W-10Cr-5Y） alloy with an average grain size of 85 nm and a relative density of 99.8% was successfully prepared.W-Cr-Y alloys with different amounts of second-phase particles were prepared by high-energy ball milling and hot isostatic pressing *** effects of composition design,ball milling parameters,and sintering parameters on the microstructure of W-Cr-Y alloys were studied.A feasible technology for controlling the synthesis of high-density nanocrystalline W-based alloys has been *** microstructure analysis of nanocrystalline W-10Cr-5Y alloy shows that there are two types of doping in the second phase:intergranular doping and intragranular *** "uniform distribution YOx-rich particles" effectively suppresses the grain growth of W and leads to the formation of nanocrystalline W-10Cr-5Y alloy.W-10Cr-5Y has an ultra-high hardness,with a Vickers hardness of 1312±12 kgf·***-temperature annealing treatment shows that W-10Cr-5Y has good thermal stability at 1000 and1100℃,as demonstrated by the comparison of Vickers hardness and grain size between annealed and unannealed alloys.

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Dynamic characteristics in an external-cavity multi-quantum-well laser

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Chinese Physics B 2018年第6期27卷 185-194页

作者： sen-lin Yan Department of Electronic Engineering Nanjing Xiaozhuang University Nanjing 211171 China

This paper outlines our studies of bifurcation, quasi-periodic road to chaos and other dynamic characteristics in an external-cavity multi-quantum-well laser with delay optical feedback. The bistable state of the laser is predicted by finding theoretically that the gain shifts abruptly between two values due to the feedback. We make a linear stability analysis of the dynamic behavior of the laser. We predict the stability scenario by using the characteristic equation while we make an approximate analysis of the stability of the equilibrium point and discuss the quantitative criteria of bifurcation. We deduce a formula for the relaxation oscillation frequency and prove theoretically that this formula function relates to the loss of carriers transferring between well regime and barrier regime, the feedback level, the delayed time and the other intrinsic parameters. We demonstrate the dynamic distribution and double relaxation oscillation frequency abruptly changing in periodic states and find the multi-frequency characteristic in a chaotic state. We illustrate a road to chaos from a stable state to quasi-periodic states by increasing the feedback level. The effects of the transfers of carriers and the escaping of carriers on dynamic behavior are analyzed, showing that they are contrary to each other via the bifurcation diagram. Also,we show another road to chaos after bifurcation through changing the linewidth enhancement factor, the photon loss rate and the transfer rate of carriers.

关键词： bifurcation chaos multi-quantum-well laser optical feedback

The secular effect of gravitational radiation damping on the periastronadvance of binary stars in second order perturbation theory

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Research in Astronomy and Astrophysics 2017年第8期17卷 81-88页

作者： lin-sen Li School of Physics Northeast Normal University Changchun 130024 China

The second order perturbation effect of gravitational radiation damping on the periastron advance of binary stars is *** second order analytic solution is obtained based on the first order theory in the 2014 article by *** results show that secular variation exists in the periastron advance of binary stars in the second order theory,but secular variation does not exist in the first order perturbation *** results for two compact binary stars(PSR J0737–3039 and M33 X-7)are given,demonstrating the theoretical significance even though the effect is very small.

关键词： binaries close—gravitational wave—celestial mechanics

Orbit and spin evolution of synchronous binary stars on the main sequence

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Research in Astronomy and Astrophysics 2012年第12期12卷 1673-1680页

作者： lin-sen Li School of Physics Northeast Normal UniversityChangchun 130024China

A set of synchronous equations are derived from a set of non-synchronous *** analytical solutions are given by solving the set of differential *** results of the evolutionary trend of the spin-orbit interaction are that the semi-major axis gradually shrinks with time;the orbital eccentricity gradually decreases with time until orbital circularization occurs;the orbital period gradually shortens with time and the rotational angular velocity of the primary component gradually speeds up with time before the orbit achieves *** theoretical results are applied to evolution of the orbit and spin of synchronous binary stars Algol A and B that are on the main *** circularization time,lifetime and the evolutionary numerical solutions of orbit and spin when circularization time occurs are estimated for Algol A and B.

关键词： binaries:close-rotation-evolution

Orbit and spin evolution of synchronous binary stars on the main sequence(a theoretical improvement to the analytical method)

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Research in Astronomy and Astrophysics 2015年第10期15卷 1695-1700页

作者： lin-sen Li School of Physics Northeast Normal University

This paper provides a method to study the solution of equations for syn- chronous binary stars with large eccentricity on the main sequence. The theoretical results show that the evolution of the eccentricity is linear with time or follows an exponential form, and the semi-major axis and spin vary with time in an exponen- tial form that are different from the results given in a previous paper. The improved method is applicable in both cases of large eccentricity and small eccentricity. In ad- dition, the number of terms in the expansion of a series with small eccentricity is very long due to the series converging slowly. The advantage of this method is that it is applicable to cases with large eccentricity due to the series converging quickly. This paper chooses the synchronous binary star V1143 Cyg that is on the main sequence and has a large eccentricity （e = 0.54） as an example calculation and gives the nu- merical results. Lastly, the evolutionary tendency including the evolution of orbit and spin, the time for the speed up of spin, the circularization time, the orbital collapse time and the life time are given in the discussion and conclusion. The results shown in this paper are an improvement on those from the previous paper.

关键词： binaries: close -- rotation -- evolution

Theory of Dynamics In-Phase Locking and Quasi-Period Synchronization in Two Mutually Coupled Multi-Quantum-Well Lasers

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Communications in Theoretical Physics 2011年第3期55卷 481-488页

作者： YAN sen-lin Department of Physics and Electronic Engineering Nanjing Xiaozhuang University Nanjing 211171 China

Abstract We study dynamics in two mutually coupling multi-quantum-well lasers. We carry out theoretical and numerical analysis of synchronization, anti-synchronization, in-phase locking in the two identical lasers but detuning, in detain. It is proved that the coupling level determines stability of the lasers by analyzing the eigenvalue equation. Critical case of locking is discussed via the phase difference equation. Quasi-period and stable states in the two lasers are investigated via varying the current, detuning and coupling level.

关键词： in-phase locking synchronization multi-quantum-well laser coupling

Pointwise Approximation Theorems for Combinations and Derivatives of Bernstein Polynomials

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Acta Mathematica Sinica,English Series 2005年第5期21卷 1241-1248页

作者： lin sen XIE Department of Mathematics Lishui University Lishui 323000 P. R. China

We establish the pointwise approximation theorems for the combinations of Bernstein polynomials by the rth Ditzian-Totik modulus of smoothness wФ^r（f, t） where Ф is an admissible step-weight function. An equivalen... 详细信息

关键词： Bernstein polynomials Combinations and derivatives Ditzian-Totik modulus of smoothness Pointwise approximation

Visuospatial Memory Alteration in Alzheimer’s Disease

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Neuroscience Bulletin 2020年第8期36卷 829-830页

作者： sen lin Department of Ophthalmology Daping HospitalArmy Medical Center of the People's Liberation ArmyArmy Medical UniversityChongqing 400042China

Although the treatment and drug discovery for Alzheimer’s disease (AD) are limited and some have failed recently,the search for potential biomarkers and early predictors *** is not only characterized by the decline o... 详细信息

关键词： Alzheimer impairment treatment

Controlling Chaos in a Semiconductor Laser via Weak Optical Positive Feedback and Modulating Amplitude

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Communications in Theoretical Physics 2007年第3期47卷 491-494页

作者： YAN sen-lin Physical Department Nanjing Xiaozhuang College Nanjing 210017 China

Numerical analysis of weak optical positive feedback （OPF） controlling chaos is studied in a semiconductor laser. The physical model of controlling chaos produced via modulating the current of semiconductor laser is presented under the condition of OPF. We find the physical mechanism that the nonlinear gain coefficient and linewidth enhance- ment factor of the laser are affected by OPF so that the dynamical behaviour of the system can be efficiently controlled. Chaos is controlled into a single-periodic state, a dual-periodic state, a tri-periodic state, a quadr-periodic state, a pentaperiodic state, and the laser emitting powers are increased by OPF in simulations. Lastly, another chaos-control method with modulating the amplitude of the feedback light is presented and numerically simulated to control chaotic laser into multi-periodic states.

关键词： chaos control positive feedback period

Reaction Effect of Gravitational Radiation of Rotating Ellipsoid as Central Body upon the Variation of Celestial Orbital Plane

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Chinese Physics Letters 1997年第5期14卷 328-331页

作者： LI lin-sen Department of Physics Northeast Normal UniversityChangchun 130024

The Reaction effect of gravitational radiation emitted from central body with quadrupole moment on the variation of celestial orbital plane was studied in *** derive the formulas for the relation between the variation of the inclination of the orbital plane and contraction of the orbital radius with *** expressions deduced were applied to the estimation for the evolution of the systems of planet-satellite(Jupiter-2 and Neptune-1).

关键词： orbital radius contraction