A5100326964- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Fiber Laser Technologies
- Quantum optics and atomic interactions
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Spectroscopy and Laser Applications
- Scientific Measurement and Uncertainty Evaluation
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Graphene research and applications
- Laser-Matter Interactions and Applications
- Quantum, superfluid, helium dynamics
- Fiber-reinforced polymer composites
- Atomic and Molecular Physics
- Advanced MRI Techniques and Applications
- Optical and Acousto-Optic Technologies
- Innovative Teaching and Learning Methods
- Theoretical and Computational Physics
- Magnetic Properties and Applications
- Particle physics theoretical and experimental studies
- Geological Modeling and Analysis
- Magnetic and transport properties of perovskites and related materials
- Surface and Thin Film Phenomena
Tsinghua University
2016-2025
Xinjiang Institute of Ecology and Geography
2025
Chinese Academy of Sciences
2019-2025
Xinjiang Agricultural University
2025
Beijing Normal University
2003-2024
Space Engineering University
2020-2024
Changchun Institute of Optics, Fine Mechanics and Physics
2019-2024
Peking University
2001-2023
China University of Petroleum, Beijing
2023
Shandong Mental Health Center
2023
The synchronisation of time and frequency between remote locations is crucial for many important applications. Conventional dissemination often makes use satellite links. Recently, the communication fibre network has become an attractive option long-distance dissemination. Here, we demonstrate accurate transfer via 80 km link Tsinghua University (THU) National Institute Metrology China (NIM). Using a 9.1 GHz microwave modulation timing signal carried by two continuous-wave lasers transferred...
The Tianshan wild fruit forest region is a vital repository of plant biodiversity, particularly rich in the unique genetic resources endemic medicinal plants this ecological niche. However, human activities such as unregulated mining and excessive grazing have led to significant reduction diversity these plants. This study represents first application DNA barcoding 101 found forests, using three loci along with morphological identification methods. A phylogenetic analysis was performed...
Abstract Until recent times, most studies on supporting simulation‐based scientific discovery learning adopted the ad hoc strategies‐oriented approach. This paper makes a systematic analysis of internal conditions to propose triple scheme for support design that includes interpretative (IS), experimental (ES), and reflective (RS) . The experiment was conducted with 78 students (aged from 12 13 years) examine effects IS ES using 2x2 between‐subjects design. main results were: significant were...
BackgroundAccording to statistics, about one-fifth of the world's elderly people suffer from sleep disorders, and problem disorders in is extremely serious, this one important causes chronic diseases such as hypertension, hyperlipidemia, diabetes mellitus, coronary heart disease elderly. The positive effect Tai Chi exercise therapy on problems has been confirmed, but at present, specific duration improvement with moderate severe varies.ObjectiveMETA analysis was used investigate find that...
Abstract Learning support studies involving simulation‐based scientific discovery learning have tended to adopt an ad hoc strategies‐oriented approach in which the strategies are typically pre‐specified according learners' difficulties particular activities. This article proposes a more integrated approach, triple scheme for design on basis of systematic analysis internal conditions learning. The involves: (a) interpretative that helps learners with knowledge access and generation meaningful...
We report on the development of a microwave frequency standard based laser-cooled 171Yb+ ion trap system. The electronics , lasers, and magnetic shields are integrated into single physical package. With over 105 ions stably trapped, system offers high signal-to-noise ratio Ramsey line-shape. In comparison with previous work, instability clock was further improved to 8.5×10-13/τ for averaging times between 10 1000 s. Essential systematic shifts uncertainties also estimated.
Precision determination of the hyperfine splitting cadmium ions is essential to study space-time variation fundamental physical constants and isotope shifts. In this work, we present precision frequency measurement excited-state $^2{P}_{3/2}$ $^{111,113}\mathrm{Cd}^+$ using laser-induced fluorescence technique. By introducing technology sympathetic cooling setting up free-space beat detection unit based on optical comb, uncertainties are improved 14.8 kHz 10.0 kHz, respectively, two orders...
Precision determination of the hyperfine splitting (HFS) cadmium ions is useful to study space-time variation fundamental physical constants and isotope shifts. In this work, we present precision frequency measurement excited-state 2P3/2 111,113Cd+ using laser-induced fluorescence technique. By introducing technology sympathetic cooling measuring doublet line transition exploitation an optical comb system, uncertainties are improved 16 12 kHz, respectively, two orders magnitude higher than...
The compact and low-cost surface-emitting lasers in the 3–5 μm mid-infrared (MIR) range are highly desirable for important applications such as gas detection, noninvasive medical diagnosis, infrared scene projection. Due to intrinsic noise of general narrow-bandgap semiconductors, MIR is a challenging region photonics. Here, we demonstrate first black phosphorus (BP)-based laser operating at room temperature fabricated with BP active gain materials embedded into SiO2/Si3N4 open microcavity...
The accuracy of atomic isotope shift factors limits the extraction nuclear charge radii from measurements because determining these is experimentally and theoretically challenging. Here, ${\mathrm{Cd}}^{+}\phantom{\rule{4pt}{0ex}}5s{\phantom{\rule{0.16em}{0ex}}}^{2}{S}_{1/2}\ensuremath{\rightarrow}5p{\phantom{\rule{0.16em}{0ex}}}^{2}{P}_{3/2}$ transition measured precisely using laser-induced fluorescence a sympathetically cooled large ${\mathrm{Cd}}^{+}$ ion crystal. A King-plot analysis...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorescence Spectroscopy and Integral Equation Studies of Preferential Solvation in Supercritical Fluid MixturesJianwei Zhang, Lloyd L. Lee, Joan F. BrenneckeCite this: J. Phys. Chem. 1995, 99, 22, 9268–9277Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://pubs.acs.org/doi/10.1021/j100022a048https://doi.org/10.1021/j100022a048research-articleACS PublicationsRequest reuse...
A microwave frequency standard based on laser-cooled (113)Cd(+) ions has been developed in recent years, and the short-term instability is measured to be 6.1×10(-13)/√τ. By comparing Cd(+) clock a superior reference, ground-state hyperfine splitting of precisely 15199862855.0192(10) Hz with fractional precision 6.6×10(-14). This result consistent previous results, measurement improved by nearly one order more than best reported before.
The ground-state hyperfine splittings of laser-cooled ${}^{113}$Cd${}^{+}$ and ${}^{111}$Cd${}^{+}$ ions confined in a linear Paul trap have been measured to be $15\phantom{\rule{0.16em}{0ex}}199\phantom{\rule{0.16em}{0ex}}862\phantom{\rule{0.16em}{0ex}}854.96(0.12)$ Hz $14\phantom{\rule{0.16em}{0ex}}530\phantom{\rule{0.16em}{0ex}}507\phantom{\rule{0.16em}{0ex}}349.9(1.1)$ Hz, respectively, using microwave-optical double-resonance technique. results for agrees with previous measurements very...
Low-temperature scanning tunneling spectroscopy reveals that the Kondo temperature ${T}_{K}$ of Co atoms adsorbed on Cu/Co/Cu(100) multilayers varies between 60 and 134 K as Cu film thickness decreases from 20 to 5 atomic layers. The observed change is attributed a variation density states at Fermi level ${\ensuremath{\rho}}_{F}$ induced by quantum well confined film. A model calculation based oscillations belly neck surface reproduces most features in measured ${T}_{K}$.
We report a high-performance transportable microwave frequency standard scheme based on sympathetically cooled 113Cd+ ions using 40Ca+ as coolant ions. A physical package (1.4 m3) with magnetic shielding (radial coefficient 460 000) has been built. In experiments, more than 105 were to 90 mK in Paul trap and the ion-loss time constant extends 84 hours. Without direct cooling procedures, Dick effect-limited Allan deviation due deadtimes is reduced 1.8×10−14/τ. Under our scheme, uncertainties...
We measured the ground-state hyperfine splitting of trapped 113Cd+ ions to be 15199862855.02799(27) Hz with a fractional uncertainty 1.8×10-14. The were and laser-cooled in linear quadrupole Paul trap. frequency stability was 4.2×10-13/τ, obtained from Ramsey fringes high signal-to-noise ratios taken over measurement time nearly 5 h, which is close short-term limit estimated Dick effect. Our result consistent previously reported values, but precision four times better than best date.
Spin-torque (ST) driven magnetization dynamics have been investigated in a spin-valve structure that consists of an in-plane (IP) free layer and two fixed polarizers [magnetized IP out-of-plane (OP)]. Three distinct including no switching, periodic oscillation are identified phase diagram governed by the ST parameters. The strengths which able to switch analytically predicted supported simulations, showing torque originated from OP polarizer should be much smaller than polarizer. dual could...