期刊文献+
共找到11,781篇文章
< 1 2 250 >
每页显示 20 50 100
芬兰FSM学校体育一体化项目发展路径的镜鉴与启示
1
作者 李恒朔 郭强 《浙江体育科学》 2024年第4期69-77,共9页
运用文献资料、案例分析等方法,梳理芬兰FSM一体化项目内在逻辑、运行机制并结合国情提出推进路径。芬兰FSM项目一体化发展路径:①制度设计与实施的有效协同;②体育素养与校园文化的整体建设;③课内外服务内容的延伸与衔接;④行动与评... 运用文献资料、案例分析等方法,梳理芬兰FSM一体化项目内在逻辑、运行机制并结合国情提出推进路径。芬兰FSM项目一体化发展路径:①制度设计与实施的有效协同;②体育素养与校园文化的整体建设;③课内外服务内容的延伸与衔接;④行动与评价主体的一致性设计。基于此,提炼了对我国学校体育一体化发展的推进路径:①学校体育政策导向、制度框架与行动指南的有序衔接;②三位一体的学术驱动、学校组织、学生参与的正向循环;③学校共同体权责监察、过程监控、效果监督的有效评估。 展开更多
关键词 双减 fsm 学校体育 一体化
下载PDF
Intense Mid-Infrared Laser Pulse Generated via Flying-Mirror Red-Shifting in Near-Critical-Density Plasmas
2
作者 鲁瑜 李东澳 +2 位作者 李倩妮 邵福球 余同普 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第2期42-46,共5页
Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-criticaldensity plasmas.It is found theoretically and numerically that the radiation pressure of a circularly po... Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-criticaldensity plasmas.It is found theoretically and numerically that the radiation pressure of a circularly polarized laser pulse first compresses the plasma electrons to form a dense flying mirror with a relativistic high speed.The pulse reflected by the mirror is red-shifted to the mid-infrared range.Full three-dimensional simulations demonstrate that the central wavelength of the mid-infrared pulse is tunable from 3µm to 14µm,and the laser energy conversion efficiency can reach as high as 13%.With a 0.5–10 PW incident laser pulse,the generated mid-infrared pulse reaches a peak power of 10–180 TW,which is interesting for various applications in ultrafast and high-field sciences. 展开更多
关键词 mirror Infrared Pulse
下载PDF
Improved mass relations of mirror nuclei
3
作者 Cheng Xu Man Bao 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第9期178-185,共8页
In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a shell.The root-mean-squared deviation is 66 keV for 116 nuclei with neutro... In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a shell.The root-mean-squared deviation is 66 keV for 116 nuclei with neutron number N≥10,as com-pared with experimental data compiled in the AME2020 database.The predicted mass excesses of 173 proton-rich nuclei,including 98 unknown nuclei,are tabulated in the Supplemental Material herein with competitive accuracy. 展开更多
关键词 Nuclear mass mirror nuclei Proton-rich nuclei
下载PDF
Cleaning of two mirrors in the first mirror unit using radiofrequency capacitively coupled plasma
4
作者 Chenxue WANG Rong YAN +5 位作者 Yuming LIU Su XU Lei MU Wei ZHENG Rui DING Junling CHEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第9期165-171,共7页
First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the in... First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies. 展开更多
关键词 first mirror unit dual-mirror cleaning REFLECTIVITY sputtering rate
下载PDF
Fuzzy Proportional Integral Derivative control of a voice coil actuator system for adaptive deformable mirrors
5
作者 Ziqiang Cui Heng Zuo +4 位作者 Weikang Qiao Hao Li Fujia Du Yifan Wang Jinrui Guo 《Astronomical Techniques and Instruments》 CSCD 2024年第3期179-186,共8页
Research on adaptive deformable mirror technology for voice coil actuators(VCAs)is an important trend in the development of large ground-based telescopes.A voice coil adaptive deformable mirror contains a large number... Research on adaptive deformable mirror technology for voice coil actuators(VCAs)is an important trend in the development of large ground-based telescopes.A voice coil adaptive deformable mirror contains a large number of actuators,and there are problems with structural coupling and large temperature increases in their internal coils.Additionally,parameters of the traditional proportional integral derivative(PID)control cannot be adjusted in real-time to adapt to system changes.These problems can be addressed by introducing fuzzy control methods.A table lookup method is adopted to replace real-time calculations of the regular fuzzy controller during the control process,and a prototype platform has been established to verify the effectiveness and robustness of this process.Experimental tests compare the control performance of traditional and fuzzy proportional integral derivative(Fuzzy-PID)controllers,showing that,in system step response tests,the fuzzy control system reduces rise time by 20.25%,decreases overshoot by 78.24%,and shortens settling time by 67.59%.In disturbance rejection experiments,fuzzy control achieves a 46.09%reduction in the maximum deviation,indicating stronger robustness.The Fuzzy-PID controller,based on table lookup,outperforms the standard controller significantly,showing excellent potential for enhancing the dynamic performance and disturbance rejection capability of the voice coil motor actuator system. 展开更多
关键词 Adaptive optics Deformable mirror Voice coil actuator Fuzzy control
下载PDF
An electromagnetic semi-active dynamic vibration absorber for thin-walled workpiece vibration suppression in mirror milling
6
作者 Jianghua KONG Bei DING +3 位作者 Wei WANG Zhixia WANG Juliang XIAO Hongyun QIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第8期1315-1334,共20页
As critical components of aircraft skins and rocket fuel storage tank shells,large thin-walled workpieces are susceptible to vibration and deformation during machining due to their weak local stiffness.To address thes... As critical components of aircraft skins and rocket fuel storage tank shells,large thin-walled workpieces are susceptible to vibration and deformation during machining due to their weak local stiffness.To address these challenges,we propose a novel tunable electromagnetic semi-active dynamic vibration absorber(ESADVA),which integrates with a magnetic suction follower to form a followed ESADVA(follow-ESADVA)for mirror milling.This system combines a tunable magnet oscillator with a follower,enabling real-time vibration absorption and condition feedback throughout the milling process.Additionally,the device supports self-sensing and frequency adjustment by providing feedback to a linear actuator,which alters the distance between magnets.This resolves the traditional issue of being unable to directly monitor vibration at the machining point due to space constraints and tool interference.The frequency shift characteristics and vibration absorption performance are comprehensively investigated.Theoretical and experimental results demonstrate that the prototyped follow-ESADVA achieves frequency synchronization with the milling tool,resulting in a vibration suppression rate of approximately 47.57%.Moreover,the roughness of the machined surface decreases by18.95%,significantly enhancing the surface quality.The results of this work pave the way for higher-quality machined surfaces and a more stable mirror milling process. 展开更多
关键词 semi-active dynamic vibration absorber(SADVA) mirror milling selfsensing vibration absorption tuning thin-walled workpiece
下载PDF
Virtual Reality-Based Mirror Therapy for Upper Extremity Function among Stroke Patients:A Meta-analysis and Systematic Review
7
作者 Juan ZHOU 《Medicinal Plant》 2024年第5期44-49,共6页
[Objectives]To investigate the evidence-based effect of virtual reality-based mirror therapy system(VR-MT)on upper extremity function among stroke patients.[Methods]A systematic electronic searching of the Medline,Pub... [Objectives]To investigate the evidence-based effect of virtual reality-based mirror therapy system(VR-MT)on upper extremity function among stroke patients.[Methods]A systematic electronic searching of the Medline,PubMed,Web of Science and CNKI was initially performed up to June 10,2024.The risk of bias of the included studies was evaluated using RevMan 5.4 software based on the Cochrane Handbook for Systematic Reviews.The random-effects model or fixed-effects models was employed to estimate the standardized mean difference(SMD).The subgroup analyses were conducted exploring theVR-MT type(immersive or non-immersive)and comparing with MT or control group.[Results]In total 8 studies with a total of 273 stroke patients were included in this review.The pooled analysis of these trials showed a statistically significant enhancement inFMA-UE scores(6 studies,SMD=0.72,[95%CI 0.37 to 1.06];P<0.0001,I^(2)=31%)and Box and Block Test(BBT)(3 studies,SMD=0.49,[95%C/0.05 to 0.93];P=0.03,I^(2)=0%),rather than Manual Function Test(MFT)scores(3 studies,SMD=0.38,[95%CI-0.09 to 0.84];P=0.11,I^(2)=0%)following the application of reality-based mirror therapy.Additionally,the subgroup analysis results indicated that immersive VR-MT can significantly improve FMA-UE(5studies,SMD=0.73,[95%CI 0.24 to 1.23];P=0.004,I^(2)=43%).In contrast,the overall effect of non-immersive VR-MT was non-significant(2 studies,SMD=0.33,[95%CI-0.69 to 1.34];P=0.53,I^(2)=72%).[Conclusions]In this systematic review and meta-analysis,our findings indicate that immersiveVR-MT has the potential to improve upper extremity function among stroke patients. 展开更多
关键词 STROKE mirror therapy Virtual reality Upper extremity function META-ANALYSIS
下载PDF
From Mirror Theory to Oedipus Complex:A Lacanian Interpretation of Night,Mother
8
作者 LIU Mu-zi 《Journal of Literature and Art Studies》 2024年第9期759-764,共6页
Jacques Lacan reinterpreted Freud’s psychoanalytic theory based on Saussure’s linguistics,and his theories such as the Mirror stage and the Oedipus complex had a significant impact on contemporary psychoanalysis.In ... Jacques Lacan reinterpreted Freud’s psychoanalytic theory based on Saussure’s linguistics,and his theories such as the Mirror stage and the Oedipus complex had a significant impact on contemporary psychoanalysis.In the play Night,Mother,the reasons for Jessie’s tragedy are diverse,among which the excessive protection of Jessie by her mother Thelma is an important reason for Jessie’s tragedy.Starting from Lacan’s Mirror stage theory and the Oedipus complex,this paper will explore how this intimate but heavy maternal love influenced Jessie’s path to finding her true“ego”. 展开更多
关键词 mirror stage Oedipus complex mother-daughter relationships identity construction
下载PDF
Mirror Stage Theory Analysis of Bravery in Zootopia(2016)and Nezha(2019)
9
作者 ZOU Jia-cheng 《Journal of Literature and Art Studies》 2024年第1期40-47,共8页
American Hollywood animated films have conquered the world.In recent years,many successful works have appeared in domestic animated films,bringing new vitality to the Chinese animated film industry.Based on Lacan’s M... American Hollywood animated films have conquered the world.In recent years,many successful works have appeared in domestic animated films,bringing new vitality to the Chinese animated film industry.Based on Lacan’s Mirror Stage Theory,this study attempts to start from the bravery of Judy and Nezha,the protagonists of Zootopia(2016)and Nezha(2019).It analyzes and compares their embodiment,formation,influence and reflection with real society to solve the problems of the two brave characters’formation causes,characteristic differences and social influences,including racial discrimination,individualism in American society and family problems in Chinese society.This study sheds light on the transmission of intercultural values in animated films. 展开更多
关键词 mirror Stage Theory Zootopia Nezha:Birth of the Demon Child Judy Nezha Bravery
下载PDF
改进FSM步态检测的行人航位推算方法 被引量:3
10
作者 李静 王庆 +1 位作者 王胜利 许九靖 《大地测量与地球动力学》 CSCD 北大核心 2023年第2期164-167,202,共5页
针对传统波峰检测法的步态识别率低以及普适性和稳定性较差等问题,提出改进FSM步态检测的行人航位推算方法。该方法关注当前的步伐状态,将一个步态周期划分为5种状态并引入峰值阈值限制,从用户不同运动状态和手机模态进行实验分析。结... 针对传统波峰检测法的步态识别率低以及普适性和稳定性较差等问题,提出改进FSM步态检测的行人航位推算方法。该方法关注当前的步伐状态,将一个步态周期划分为5种状态并引入峰值阈值限制,从用户不同运动状态和手机模态进行实验分析。结果表明,该算法不但具有较高的步态识别准确率,而且可减小航位推算时间累积误差,具有一定的可靠性和稳定性,能够满足室内定位需求。 展开更多
关键词 fsm 步态检测 行人航位推算 室内定位
下载PDF
Constraining nuclear symmetry energy with the charge radii of mirror-pair nuclei 被引量:6
11
作者 Rong An Shuai Sun +1 位作者 Li-Gang Cao Feng-Shou Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期154-163,共10页
The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the ... The nuclear charge radius plays a vital role in determining the equation of state of isospin asymmetric nuclear matter.Based on the correlation between the differences in charge radii of mirror-partner nuclei and the slope parameter(L)of symmetry energy at the nuclear saturation density,an analysis of the calibrated slope parameter L was performed in finite nuclei.In this study,relativistic and nonrelativistic energy density functionals were employed to constrain the nuclear symmetry energy through the available databases of the mirror-pair nuclei^(36)Ca–^(36)S,^(38)Ca–^(38)Ar,and ^(54)Ni–^(54)Fe.The deduced nuclear symmetry energy was located in the range 29.89–31.85 MeV,and L of the symmetry energy essentially covered the range 22.50–51.55 MeV at the saturation density.Moreover,the extracted L_(s) at the sensitivity density p_(s)=0.10 fm^(-3) was located in the interval range 30.52–39.76 MeV. 展开更多
关键词 Symmetry energy Charge radii mirror nuclei
下载PDF
High-resolution visible imaging with piezoelectric deformable secondary mirror: experimental results at the 1.8-m adaptive telescope 被引量:2
12
作者 Youming Guo Kele Chen +7 位作者 Jiahui Zhou Zhengdai Li Wenyu Han Xuejun Rao Hua Bao Jinsheng Yang Xinlong Fan Changhui Rao 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第12期15-26,共12页
Integrating deformable mirrors within the optical train of an adaptive telescope was one of the major innovations in astronomical observation technology,distinguished by its high optical throughput,reduced optical sur... Integrating deformable mirrors within the optical train of an adaptive telescope was one of the major innovations in astronomical observation technology,distinguished by its high optical throughput,reduced optical surfaces,and the incorporation of the deformable mirror.Typically,voice-coil actuators are used,which require additional position sensors,internal control electronics,and cooling systems,leading to a very complex structure.Piezoelectric deformable secondary mirror technologies were proposed to overcome these problems.Recently,a high-order piezoelectric deformable secondary mirror has been developed and installed on the 1.8-m telescope at Lijiang Observatory in China to make it an adaptive telescope.The system consists of a 241-actuator piezoelectric deformable secondary mirror,a 192-sub-aperture Shack-Hartmann wavefront sensor,and a multi-core-based real-time controller.The actuator spacing of the PDSM measures 19.3 mm,equivalent to approximately 12.6 cm when mapped onto the primary mirror,significantly less than the voicecoil-based adaptive telescopes such as LBT,Magellan and VLT.As a result,stellar images with Strehl ratios above 0.49 in the R band have been obtained.To our knowledge,these are the highest R band images captured by an adaptive telescope with deformable secondary mirrors.Here,we report the system description and on-sky performance of this adaptive telescope. 展开更多
关键词 adaptive optics deformable secondary mirror visible imaging
下载PDF
基于FSM的管道腐蚀监测技术实验研究
13
作者 祁永刚 段汝娇 +1 位作者 杨绪运 付志强 《中国特种设备安全》 2023年第S02期56-61,共6页
FSM作为一种新型的管道在线腐蚀监测方法,具有良好的应用前景。压力管道腐蚀缺陷中以局部小腐蚀坑最为常见,这也是FSM方法中研究的重点。本文基于FSM方法对压力管道常见的圆形和矩形小腐蚀坑展开实验研究,结果表明FSM方法对于小体积型... FSM作为一种新型的管道在线腐蚀监测方法,具有良好的应用前景。压力管道腐蚀缺陷中以局部小腐蚀坑最为常见,这也是FSM方法中研究的重点。本文基于FSM方法对压力管道常见的圆形和矩形小腐蚀坑展开实验研究,结果表明FSM方法对于小体积型缺陷敏感,实验中监测精度为0.5 mm,并可准确反映缺陷增长过程,对管道安全运行具有重要意义。 展开更多
关键词 压力管道 腐蚀监测 场指纹法(fsm)
下载PDF
Two types of mirror mode waves in the Kronian magnetosheath 被引量:1
14
作者 XinYa Duanmu ZhongHua Yao +1 位作者 Yong Wei ShengYi Ye 《Earth and Planetary Physics》 EI CSCD 2023年第3期414-420,共7页
A mirror mode wave is a fundamental magnetic structure in the planetary space environment that is persistently compressed by solar wind,especially in the magnetosheath.Mirror modes have been widely identified in the m... A mirror mode wave is a fundamental magnetic structure in the planetary space environment that is persistently compressed by solar wind,especially in the magnetosheath.Mirror modes have been widely identified in the magnetosheaths of the Earth and other planets in the solar system,yet the understanding of mirror mode waves on extraterrestrial planets is not as comprehensive as that on the Earth.Using magnetic field data collected by the Cassini spacecraft,we found peak and dip types according to the magnetic morphology(i.e.,structures with higher or lower magnetic strengths than the background field).Moreover,mirror mode waves and electromagnetic ion cyclotron waves were found one after the other,implying that the two wave modes may evolve into one another in the Kronian magnetosheath.The results indicate that many fundamental plasma processes associated with the mirror mode structure exist in the Kronian magnetosheath.The energy conversion in Saturn’s magnetosheath may provide key insights that will aid in understanding giant planetary magnetospheric processes. 展开更多
关键词 mirror mode wave CASSINI Kronian magnetosheath electromagnetic ion cyclotron wave
下载PDF
Is a mirror necessary for mirror therapy?
15
作者 Richard G.Carson Alannah Morley 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第12期2703-2704,共2页
Since it was first described as a method to treat phantom limb pain, mirror therapy(MT) has been applied in many areas of rehabilitation. Its seminal application with the aim of restoring motor function following stro... Since it was first described as a method to treat phantom limb pain, mirror therapy(MT) has been applied in many areas of rehabilitation. Its seminal application with the aim of restoring motor function following stroke is considered to be that of Altschuler et al.(1999). 展开更多
关键词 mirror al. THERAPY
下载PDF
Effects of Different Feedback Conditions on Sensorimotor Adaptation Revealed in a Mirror Reversal Paradigm
16
作者 Jingyue Xu Chen Yang +6 位作者 Mengzhan Liufu Shuai Chang Jinpeng Chen Feng Lu Alkis M. Hadjiosif Adrian M. Haith Xueqian Deng 《Journal of Behavioral and Brain Science》 2023年第7期127-141,共15页
Humans are able to overcome sensory perturbations imposed on their movements through motor learning. One of the key mechanisms to accomplish this is sensorimotor adaptation, an implicit, error-driven learning mechanis... Humans are able to overcome sensory perturbations imposed on their movements through motor learning. One of the key mechanisms to accomplish this is sensorimotor adaptation, an implicit, error-driven learning mechanism. Past work on sensorimotor adaptation focused mainly on adaptation to rotated visual feedback—A paradigm known as visuomotor rotation. Recent studies have shown that sensorimotor adaptation can also occur under mirror-reversed visual feedback. In visuomotor rotation, sensorimotor adaptation can be driven by both endpoint and online feedback [1] [2]. However, it’s not been clear whether both kinds of feedback can similarly drive adaptation under a mirror reversed perturbation. We performed a study to establish what kinds of feedback can drive adaptation under mirror reversal. In the first two conditions, the participants were asked to ignore visual feedback. In the first condition, we provided mirror reversed online feedback and endpoint feedback. We reproduced previous findings showing that online feedback elicited adaptation under mirror reversal. In a second condition, we provided mirror reversed endpoint feedback. However, in the second condition, we found that endpoint feedback alone failed to elicit adaptation. In a third condition, we provided both types of feedback at the same time, but in a conflicting way: endpoint feedback was non-reversed while online feedback was mirror reversed. The participants were asked to ignore online visual feedback and try to hit the target with help from veridical endpoint feedback. In the third condition, in which veridical endpoint feedback and mirror reversed online feedback were provided, adaptation still occurred. Our results showed that endpoint feedback did not elicit adaptation under mirror reversal but online feedback did. This dissociation between effects of endpoint feedback and online feedback on adaptation under mirror reversal suggests that adaptation under these different kinds of feedback might in fact operate via distinct mechanisms. 展开更多
关键词 Endpoint Feedback Online Feedback Motor Learning Implicit Adaptation mirror Reversal
下载PDF
Experimental studies of cusp stabilization in Keda Mirror with AXisymmetricity(KMAX)
17
作者 李清 朱光辉 +3 位作者 任宝明 应嘉成 杨智达 孙玄 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第2期20-26,共7页
Stabilization of the axisymmetric magnetic mirror relies on the pressure-weighted magnetic field curvature.We report a new experiment by configuring a magnetic cusp structure to stabilize m=1 interchange mode in the K... Stabilization of the axisymmetric magnetic mirror relies on the pressure-weighted magnetic field curvature.We report a new experiment by configuring a magnetic cusp structure to stabilize m=1 interchange mode in the KMAX tandem mirror.The cusp configuration is formed by reversing currents in the two side cell coils,and a stronger cusp can lead to a more stable plasma once the null point of the cusp is less than 35–40 cm away from the device axis.The density fluctuations measured by four axial Langmuir probes are mitigated by 70%–80%.The stabilization effect is consistent with the prediction of a theoretical calculation. 展开更多
关键词 tandem mirror interchange mode density fluctuations cusp stabilization
下载PDF
STABILITY CONDITIONS AND THE MIRROR SYMMETRY OF K3 SURFACES IN ATTRACTOR BACKGROUNDS
18
作者 卢文轩 《Acta Mathematica Scientia》 SCIE CSCD 2023年第3期1007-1030,共24页
We study the space of stability conditions on K3 surfaces from the perspective of mirror symmetry. This is done in the attractor backgrounds(moduli). We find certain highly non-generic behaviors of marginal stability ... We study the space of stability conditions on K3 surfaces from the perspective of mirror symmetry. This is done in the attractor backgrounds(moduli). We find certain highly non-generic behaviors of marginal stability walls(a key notion in the study of wall crossings)in the space of stability conditions. These correspond via mirror symmetry to some nongeneric behaviors of special Lagrangians in an attractor background. The main results can be understood as a mirror correspondence in a synthesis of the homological mirror conjecture and SYZ mirror conjecture. 展开更多
关键词 mirror symmetry stability conditions K3 surfaces attractor mechanism
下载PDF
Development of aperiodic multilayer mirrors operated at W-Lβline for plasma diagnostics application
19
作者 Ze‑Hua Yang Jing‑Tao Zhu +7 位作者 Zhong‑Liang Li Hong‑Xin Luo Shang‑Yu Si Yun‑Ping Zhu Li Zhao Kuan Ren Feng Wang Rong‑Qing Yi 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第11期77-84,共8页
Multilayer interference mirrors play a pivotal role in spectroscopic diagnostic systems,which probe electron temperature and density during inertial confinement fusion processes.In this study,aperiodic Mo/B_(4)C multi... Multilayer interference mirrors play a pivotal role in spectroscopic diagnostic systems,which probe electron temperature and density during inertial confinement fusion processes.In this study,aperiodic Mo/B_(4)C multilayer mirrors of varied thick-nesses were investigated for X-ray plasma diagnostics at the 9.67-keV W-Lβline.The thickness distribution of the aperiodic multilayers was designed using the first Bragg diffraction condition and then optimized through a simplex algorithm to realize a narrow bandwidth and consistent spectral response.To enhance spectral accuracy,further refinements were undertaken by matching the grazing incidence X-ray reflectivity data with actual structural parameters.X-ray reflectivity measurements from the SSRF synchrotron radiation facility on the optimized sample showed a reflectivity of 29.7±2.6%,flat-band range of 1.3 keV,and bandwidth of 1.7 keV,making it suitable for high-temperature plasma diagnostics.The study explored the potential of predicting the 9.67 keV reflectivity spectrum using the fitting data from the grazing incidence X-ray reflectivity curves at 8.05 keV.Additionally,the short-term thermal stability of an aperiodic multilayer was assessed using temperature-dependent in situ X-ray measurements.Shifts in the reflectivity spectrum during annealing were attributed to interdiffusion and interfacial relaxation.The research team recommends the aperiodic Mo/B_(4)C multilayer mirror for operations below 300℃. 展开更多
关键词 X-ray multilayer mirror Aperiodic multilayer Flat response Sputtering deposition Synchrotron radiation
下载PDF
Eight Reasons to Consider History as a Mirror
20
作者 AUGUSTO SOTO 《China Today》 2023年第1期18-19,共2页
Understanding the China-U.S. relations from a historical perspective.WHEN President Xi Jinping met his U.S. counterpart Joe Biden on the sidelines of the G20 Summit in Bali in November, 2022, he said, "History is... Understanding the China-U.S. relations from a historical perspective.WHEN President Xi Jinping met his U.S. counterpart Joe Biden on the sidelines of the G20 Summit in Bali in November, 2022, he said, "History is the best textbook. We should take it as a mirror and let it guide the future." 展开更多
关键词 HISTORY mirror mirror
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部