here, we propose an add-drop and a channel drop filter based on two-dimensional photonic crystal all circular ring resonators. these structures are made of a square lattice of silicon rods with the refractive index n1=3.464 surrounded by air (with refractive index n2=1). the broadest photonic band gap occurs at the filling ratio of r/a = 0.17. two linear defect w1 waveguides couple to the ring....

Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth's climate. Many different types of fence have been designed and their effects on the sediment transport dynamics st...

Аннотация: В статье анализируются социально-экономические последствия развития дропшиппинга – новой формы организации продаж, стремительно завоевывающей российский рынок. Дропшиппинг открывает огромные перспективы не только для простых людей, но и для российских производителей, которые при правильном использовании возможностей дропшиппинга могут с минимальными затратами получить прямой доступ к...

We examine giant graviton with magnetic flux q in type IIA pp-wave background and find that it can move away from the origin along x4 direction in target space satisfying a nontrivial relation Rx4 = −q. This constraint is also investigated in a system of N D0-branes and it is observed that x4 enters into fuzzy algebra as a fuzzy parameter. The nontrivial relation can be regarded as a complement...