Slow light supported by electromagnetically induced transparency effect in dispersive medium is extremely susceptible with respect to Doppler detuning. In this paper, the Doppler effect induced by rotating dispersive ...Slow light supported by electromagnetically induced transparency effect in dispersive medium is extremely susceptible with respect to Doppler detuning. In this paper, the Doppler effect induced by rotating dispersive medium was considered and the effect of the velocity of rotating dispersive medium on the group velocity was studied. Based on a dispersive slow-light medium, a high sensitive optical rotation sensor for measuring absolute rotation is proposed and analysed. The sensitivity of the rotation sensor is the group delay between the counterpropagationed wave packets in the device, and scales directly with square of the group index which can reach 102-10s orders of magnitude by selecting a proper dispersive medium.展开更多
By analyzing the Einstein-box thought experiment with the principle of relativity, it is shown that Abraham’s light momentum and energy in a medium cannot constitute a Lorentz four-vector, and they consequentially br...By analyzing the Einstein-box thought experiment with the principle of relativity, it is shown that Abraham’s light momentum and energy in a medium cannot constitute a Lorentz four-vector, and they consequentially break global momentum and energy conservation laws. In contrast, Minkowski’s momentum and energy always constitute a Lorentz four-vector no matter whether in a medium or in vacuum, and the Minkowski’s momentum is the unique correct light momentum. A momentum-associated photon mass in a medium is exposed, which explains why only the Abraham’s momentum is derived in the traditional “center-of-mass-energy” approach. The EM boundary-condition matching approach, combined with Einstein light-quantum hypothesis, is proposed to analyze this thought experiment, and it is found for the first time that only from Maxwell equations without resort to the relativity, the correctness of light momentum definitions cannot be identified. Optical pulling effect is studied as well.展开更多
The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and...The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and the leaf number per plant, shoot number per plant, leaf width and leaf chlorophyll content were also investigated. The results were as follows: 1) The seedling height, fresh and dry weight, leaf number per plant, leaf width and leaf chlorophyll content of the shoots growing on MS complete culture medium were higher than those on 1/2MS, VW and 1/2VW media. The root number per plant and ratio of dry matter of the seedlings cultured on 1/2MS and 1/2VW media were higher than those on MS and VW; 2) The seedling height, fresh weight, dry weight, dry matter ratio and leaf chlorophyll content, leaf length, leaf width, root length, leaf number per plant, root number per plant of seedlings of Oncidium growing under 4 500 lx and 1 700 lx were higher than those under 750 lx. However, there was no significant difference in those growth parameters mentioned above while dealing with 4 500 lx and 1 700 lx except for the seedling height. Nevertheless, the leaf color of plants under 4 500 lx was lighter and the leaves of the lower parts became yellowish in comparison with those growing under 1 700 lx.展开更多
With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food...With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer （MODIS） data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productiv- ity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was lo- cated in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Hei- Iongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.展开更多
为了提升导弹在复杂环境下的寻的制导能力,设计了一种红外与可见光双模式导引头光学系统。该方案中采用分光镜透射红外光反射可见光,使结构布局更加紧凑,实现红外与可见光共口径,同时配合红外材料选取,实现光学被动消热差设计。中红外...为了提升导弹在复杂环境下的寻的制导能力,设计了一种红外与可见光双模式导引头光学系统。该方案中采用分光镜透射红外光反射可见光,使结构布局更加紧凑,实现红外与可见光共口径,同时配合红外材料选取,实现光学被动消热差设计。中红外模式视场角3°×2.3°,可见光模式视场角5°×4°,工作温度20℃条件下,双模式在截止频率处,MTF(Modulation Transfer Function)值均大于0.4。红外与可见光双模式光学系统适合应用于复杂环境的导弹制导,对温度有良好的适应性,具有较好的成像质量,满足系统的性能要求。展开更多
Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and...Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 10<sup>8</sup> m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.60878006 and 61078006)
文摘Slow light supported by electromagnetically induced transparency effect in dispersive medium is extremely susceptible with respect to Doppler detuning. In this paper, the Doppler effect induced by rotating dispersive medium was considered and the effect of the velocity of rotating dispersive medium on the group velocity was studied. Based on a dispersive slow-light medium, a high sensitive optical rotation sensor for measuring absolute rotation is proposed and analysed. The sensitivity of the rotation sensor is the group delay between the counterpropagationed wave packets in the device, and scales directly with square of the group index which can reach 102-10s orders of magnitude by selecting a proper dispersive medium.
文摘By analyzing the Einstein-box thought experiment with the principle of relativity, it is shown that Abraham’s light momentum and energy in a medium cannot constitute a Lorentz four-vector, and they consequentially break global momentum and energy conservation laws. In contrast, Minkowski’s momentum and energy always constitute a Lorentz four-vector no matter whether in a medium or in vacuum, and the Minkowski’s momentum is the unique correct light momentum. A momentum-associated photon mass in a medium is exposed, which explains why only the Abraham’s momentum is derived in the traditional “center-of-mass-energy” approach. The EM boundary-condition matching approach, combined with Einstein light-quantum hypothesis, is proposed to analyze this thought experiment, and it is found for the first time that only from Maxwell equations without resort to the relativity, the correctness of light momentum definitions cannot be identified. Optical pulling effect is studied as well.
文摘The effects of culture media and light intensity on in vitro growth of Oncidium 慉loha Iwanga were investigated under CO2 enrichment condition. Height, fresh and dry weight of the Oncidium seedlings were measured, and the leaf number per plant, shoot number per plant, leaf width and leaf chlorophyll content were also investigated. The results were as follows: 1) The seedling height, fresh and dry weight, leaf number per plant, leaf width and leaf chlorophyll content of the shoots growing on MS complete culture medium were higher than those on 1/2MS, VW and 1/2VW media. The root number per plant and ratio of dry matter of the seedlings cultured on 1/2MS and 1/2VW media were higher than those on MS and VW; 2) The seedling height, fresh weight, dry weight, dry matter ratio and leaf chlorophyll content, leaf length, leaf width, root length, leaf number per plant, root number per plant of seedlings of Oncidium growing under 4 500 lx and 1 700 lx were higher than those under 750 lx. However, there was no significant difference in those growth parameters mentioned above while dealing with 4 500 lx and 1 700 lx except for the seedling height. Nevertheless, the leaf color of plants under 4 500 lx was lighter and the leaves of the lower parts became yellowish in comparison with those growing under 1 700 lx.
基金STS Project of CAS,No.KFJ-EW-STS-001National Natural Science Foundation of China,No.41430861
文摘With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer （MODIS） data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productiv- ity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was lo- cated in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Hei- Iongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.
文摘为了提升导弹在复杂环境下的寻的制导能力,设计了一种红外与可见光双模式导引头光学系统。该方案中采用分光镜透射红外光反射可见光,使结构布局更加紧凑,实现红外与可见光共口径,同时配合红外材料选取,实现光学被动消热差设计。中红外模式视场角3°×2.3°,可见光模式视场角5°×4°,工作温度20℃条件下,双模式在截止频率处,MTF(Modulation Transfer Function)值均大于0.4。红外与可见光双模式光学系统适合应用于复杂环境的导弹制导,对温度有良好的适应性,具有较好的成像质量,满足系统的性能要求。
文摘Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 10<sup>8</sup> m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.
