This paper reports an experiment on laser cooling of STRb atoms in pulsed diffuse light, which is the key step towards a compact cold atom clock. It deduces an empirical formula to simulate the pulse cooling process b...This paper reports an experiment on laser cooling of STRb atoms in pulsed diffuse light, which is the key step towards a compact cold atom clock. It deduces an empirical formula to simulate the pulse cooling process based on the loading of cold atoms in cooling time and the loss in the dead time, which is in agreement with the experimental data. The formula gives a reference to select the parameters for the cold atom clock.展开更多
Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in thi...Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in this Letter, and a trained neural network is used to achieve positioning with a diffuse channel. Simulations are made to evaluate the proposed positioning algorithm. Results show that the average positioning error is reduced about 13 times, and the positioning time is reduced about two magnitudes. Moreover, the proposed algorithm is robust with a different field-of-view of the receiver and the refiectivity of the wall, which is suitable for various position- ing applications.展开更多
Measurement of light distribution in biological tissue contributes to selecting strategy and optimizing dose for biomedical application. In this letter, a photoacoustic method combined with Monte Carlo simulation was ...Measurement of light distribution in biological tissue contributes to selecting strategy and optimizing dose for biomedical application. In this letter, a photoacoustic method combined with Monte Carlo simulation was used to estimate the three-dimensional light distribution in biological tissue. The light distribution was produced by a cylindrical diffuser which interposed into tissues. The light profiles obtained by the method were compared to those detected by photo diodes. The experimental results demonstrate the feasibility of this method. The approach can play a significant role for photo-dosimetry in biomedical phototherapy.展开更多
A novel concept for concentrating both direct and indirect sunlight employing a combination of waveguiding and refractive optics is presented.More specifically,it is based on both the individual and the collective foc...A novel concept for concentrating both direct and indirect sunlight employing a combination of waveguiding and refractive optics is presented.More specifically,it is based on both the individual and the collective focusing effects of an array of refractive optical elements of specific geometry.An analytical framework and design principles regarding the geometry of the optical elements taking into account Fresnel reflection and refraction are presented.The principle of operation along with loss mechanisms and acceptance angles are discussed in detail.Ray-tracing simulations of a light concentrator designed accordingly indicate transmittance>90%with acceptance angles of≤65°at 3 suns for moderate refractive indices.It is further numerically demonstrated that the new approach allows the utilization of the dominant fraction of the solar radiation by harvesting the waste heat in addition to photovoltaic conversion with an operating energy efficiency for diffuse light>70%.展开更多
Lung biopsies examined with light microscope and electron microscope were performed in 34 cases of diffuse pulmonary disease.Open lung biopsy was done in 2 cases,
基金supported by the National Natural Science Foundation of China (Grant Nos. 10604057 and 10874193)the National High-Tech Programme (Grant No. 2006AA12Z311)the National Basic Research Programme of China (Grant No. 2005CB724506)
文摘This paper reports an experiment on laser cooling of STRb atoms in pulsed diffuse light, which is the key step towards a compact cold atom clock. It deduces an empirical formula to simulate the pulse cooling process based on the loading of cold atoms in cooling time and the loss in the dead time, which is in agreement with the experimental data. The formula gives a reference to select the parameters for the cold atom clock.
基金supported by the National Natural Science Foundation of China(Nos.61475094 and61675025)the National 973 Program of China(No.2013CB329202)
文摘Visible light positioning becomes popular recently. However, its performance is degraded by the indoor diffuse optical channel. An artificial neural-network-based visible light positioning algorithm is proposed in this Letter, and a trained neural network is used to achieve positioning with a diffuse channel. Simulations are made to evaluate the proposed positioning algorithm. Results show that the average positioning error is reduced about 13 times, and the positioning time is reduced about two magnitudes. Moreover, the proposed algorithm is robust with a different field-of-view of the receiver and the refiectivity of the wall, which is suitable for various position- ing applications.
基金supported by the National Natural Science Foundation of China(No.61178089/81201124)in part by the Natural Science Foundation of Fujian Province(No.2011Y0019)
文摘Measurement of light distribution in biological tissue contributes to selecting strategy and optimizing dose for biomedical application. In this letter, a photoacoustic method combined with Monte Carlo simulation was used to estimate the three-dimensional light distribution in biological tissue. The light distribution was produced by a cylindrical diffuser which interposed into tissues. The light profiles obtained by the method were compared to those detected by photo diodes. The experimental results demonstrate the feasibility of this method. The approach can play a significant role for photo-dosimetry in biomedical phototherapy.
基金The publication of this article has been sponsored by Vinnova through contract 2019-04927The work is done under contracts VK-1931:02 and RK-1932:08.Tribute:In memory of George Carter and Mike J.Nobes。
文摘A novel concept for concentrating both direct and indirect sunlight employing a combination of waveguiding and refractive optics is presented.More specifically,it is based on both the individual and the collective focusing effects of an array of refractive optical elements of specific geometry.An analytical framework and design principles regarding the geometry of the optical elements taking into account Fresnel reflection and refraction are presented.The principle of operation along with loss mechanisms and acceptance angles are discussed in detail.Ray-tracing simulations of a light concentrator designed accordingly indicate transmittance>90%with acceptance angles of≤65°at 3 suns for moderate refractive indices.It is further numerically demonstrated that the new approach allows the utilization of the dominant fraction of the solar radiation by harvesting the waste heat in addition to photovoltaic conversion with an operating energy efficiency for diffuse light>70%.
文摘Lung biopsies examined with light microscope and electron microscope were performed in 34 cases of diffuse pulmonary disease.Open lung biopsy was done in 2 cases,
