We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective ang...We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio(SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector's transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed.展开更多
世界卫生组织6月4日公布了该组织对191个成员国居民健康寿命的预测和排名顺序。这次排名不同以往,采取了Disability Adjusted Life Expectancy的方法,本文将它简化为DALE,所谓DALE就是预测出的健康寿命已减去居民一生中可能罹患疾病的...世界卫生组织6月4日公布了该组织对191个成员国居民健康寿命的预测和排名顺序。这次排名不同以往,采取了Disability Adjusted Life Expectancy的方法,本文将它简化为DALE,所谓DALE就是预测出的健康寿命已减去居民一生中可能罹患疾病的时间。 日本居民平均健康生活的时间74.5年,位居第一。澳大利亚排名第二:73.2岁;法国第三:73.1岁;美国排名第二十四:68.4岁;中国排第81位:男61.2,女62.3。在发展中国家位居前列。俄罗斯第91位,印度第134位。 以上所列系一个国家的平均水平,但是,在一国之内,居民平均健康生活的时间并不平均。笔者在东方网上录下了以下数据:展开更多
In this study,we investigate a variety of exact soliton solutions of general(2+1)-dimensional Bogoyavlensky–Konopelchenko equation via the exp(-Φ(η))-expansion method and modified Kudryashov method.The exact soluti...In this study,we investigate a variety of exact soliton solutions of general(2+1)-dimensional Bogoyavlensky–Konopelchenko equation via the exp(-Φ(η))-expansion method and modified Kudryashov method.The exact solutions are characterized in the form of hyperbolic,trigonometric and rational function solutions using exp(-Φ(η))-expansion method,whereas the solution in the form of hyperbolic function expression is obtained by the modified Kudryashov method.These exact solutions also include kink,bright,dark,singular and periodic soliton solutions.The graphical interpretation of the exact solutions is addressed for specific choices of the parameters appearing in the solutions.展开更多
基金National Natural Science Foundation of China(NSFC)(61372102,61571183)Natural Science Foundation of Hunan Province(2017JJ1014)
文摘We present an experimental demonstration of ghost imaging of reflective objects with different surface roughness.The influence of the surface roughness, the transverse size of the test detector, and the reflective angle on the signal-to-noise ratio(SNR) is analyzed by measuring the second-order correlation of the light field based on classical statistical optics. It is shown that the SNR decreases with an increment of the surface roughness and the detector's transverse size or a decrease of the reflective angle. Additionally, the comparative studies between the rough object and the smooth one under the same conditions are also discussed.
文摘In this study,we investigate a variety of exact soliton solutions of general(2+1)-dimensional Bogoyavlensky–Konopelchenko equation via the exp(-Φ(η))-expansion method and modified Kudryashov method.The exact solutions are characterized in the form of hyperbolic,trigonometric and rational function solutions using exp(-Φ(η))-expansion method,whereas the solution in the form of hyperbolic function expression is obtained by the modified Kudryashov method.These exact solutions also include kink,bright,dark,singular and periodic soliton solutions.The graphical interpretation of the exact solutions is addressed for specific choices of the parameters appearing in the solutions.
