410 research outputs found
The Phenomenon of “Extreme Socialization” and the Educational Function in Personality Construction
The phenomenon of “Extreme Socialization” ignores the significance of individual autonomy and uniqueness, inhibits the healthy and free development of students’ personality, violates the human-oriented educational concept, and is not conducive to the overall development of students, especially the cultivation of students’ innovative spirit. Therefore, in the process of constructing students’ personality, it is necessary to give full play to the relevant functions of education
Rosen-Zener interferometry with Ultracold Atoms
We propose a time-domain "interferometer" based on ultracold Bose atoms
loaded on a double well potential. By the adiabatic Rosen-Zener process, the
barrier between two wells is ramped down slowly, held for a while, then ramped
back. Starting with a coherent state of double well system, the final
occupations on one well show interesting interference fringes in the
time-domain. The fringe pattern is sensitive to the initial state, the
interatomic interaction, and the external forces such as gravity which can
change the shape of the double well. In this sense, this interferometric scheme
has the potentials for precision measurements with ultracold atoms. The
underlying mechanism is revealed and possible applications are discussed.Comment: 4 pages, 5 figure
A Spatiotemporal-chaos-based Encryption Having Overall Properties Considerably Better Than Advanced Encryption Standard
Spatiotemporal chaos of a two-dimensional one-way coupled map lattice is used
for chaotic cryptography. The chaotic outputs of many space units are used for
encryption simultaneously. This system shows satisfactory cryptographic
properties of high security; fast encryption (decryption) speed; and robustness
against noise disturbances in communication channel. The overall features of
this spatiotemporal-chaos-based cryptosystem are better than chaotic
cryptosystems known so far, and also than currently used conventional
cryptosystems, such as the Advanced Encryption Standard (AES).Comment: 11 pages, 3 figure
Light scattering detection of quantum phases of ultracold atoms in optical lattices
Ultracold atoms loaded on optical lattices can provide unprecedented
experimental systems for the quantum simulations and manipulations of many
quantum phases. However, so far, how to detect these quantum phases effectively
remains an outstanding challenge. Here, we show that the optical Bragg
scattering of cold atoms loaded on optical lattices can be used to detect many
quantum phases which include not only the conventional superfluid and Mott
insulating phases, but also other important phases such as various kinds of
density waves (CDW), valence bond solids (VBS), CDW supersolids and VBS
supersolids.Comment: 4 pages, 3 colour figures, to appear in Phys. Rev. A, Rapid
Communicatio
Monitoring Crop Carotenoids Concentration by Remote Sensing
Assessment of carotenoids (Car) content provides a valuable insight into clarifying the mechanisms of plant photoprotection and light-adaption and is critical for stress diagnoses in plants. Due to their small proportion in the overall total pigment content and to the overlapping of spectral absorption features with chlorophylls (Chl) in the blue region of the spectrum, accurate estimation of Car content in plants, from remotely sensed data, is challenging. Previous studies made progress in Car content estimation at both the leaf and canopy level with remote sensing techniques. However, established spectral indices and methods for Car estimation in most studies that generally rely on specific and limited measured data might lack predictive accuracy for Car estimation and lack sensitivity to low or high Car content in various species and at different growth stages. In this chapter, a new carotenoid index (CARI) was proposed for foliar Car assessment with abundant simulated leaf data and various measured leaf reflectances. Detailed analysis on the mechanism, formation and performance of the new spectral index on Car retrieval was presented. Analysis results suggested that accurate nondestructive estimation of foliar Car content with CARI could be achieved at the leaf scale, through remote sensing techniques
Compact hollow waveguide mid-infrared gas sensor for simultaneous measurements of ambient CO2 and water vapor
A compact, sensitive and stable hollow waveguide (HWG) mid-infrared gas sensor, based on gas absorption lines using wavelength modulation spectroscopy with a second harmonic (WMS-2f) detection scheme, was developed for simultaneous measurements of ambient CO 2 and water vapor. Optimization of the laser modulation parameters and pressure parameter in the HWG are performed to improve the strength of the WMS-2f signal and hence the detection limit, where 14.5-time for CO 2 and 8.5-time for water vapor improvement in system detection limit is achieved compared to those working at 1 atm. The stability of the sensor has been improved significantly by optimizing environmental disturbances, incoupling alignment of the HWG and laser scanning frequency. An Allan variance analysis shows detection limit of the developed sensor of ~3 ppmv for CO 2 and 0.018% for water vapor, which correspond to an absorbance of 2.4 × 10 -5 and 2.7 × 10 -5 , with a stability time of 160 s, respectively. Ambient CO 2 and water vapor measurement have been performed in two days in winter and spring separately. The measurement precision is further improved by applying a Kalman adaptive filter. The HWG gas sensor demonstrates the ability in environmental monitoring and the potential to be used in other areas, such as industrial production and biomedical diagnosis
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