Predicted influence of overhead transmission lines on land-use transfer: A case study on landscape and famous scenery

Taking Baihetan—Jiangsu ±800kV UHVDC power transmission project as an example, the influence of tower foundation on land-use types and functions were predicted using ArcGIS platform and eCognition Developer. Through the construction of land-use transfer matrix analysis, the change of land-use transfer situation and structure were discussed. Our results showed that the forest transfer intensities (RT) of Tangya River Scenic spot and Three Gorges Scenic area were 0.64 and 1.49 respectively, the RT of bushes and grasses in Tangya River Scenic spot and Three Gorges Scenic area were 1.01 and 0.37. The RT of forest, bushes and grasses were both not high. The permanent occupation area of project was all transferred into building land, the construction land dynamics degrees (KT) of Tangya River Scenic spot and Three Gorges Scenic area were +0.40% and +0.031% respectively, which were both low. Thus we drew a conclusion that the project construction would have a slight impact on land use pattern and function and would not affect the overall ecological function and structure of landscape and famous scenery.

Theoretical and Experimental Study on the Transmission Loss of a Side Outlet Muffler

Vibration and noise reduction methods are important research directions in many industries. Mufflers are widely used in pipelines to reduce noise and vibration transmission. A theoretical analysis is conducted to determine the noise reduction mechanism of a muffler with a side outlet, and the results are verified with experiments. The quadrupole parameters of the muffler are obtained using transfer matrix analysis, and sensitivity analysis of the quadrupole parameters is conducted. The influence of the side outlet location on the transmission loss of the muffler is investigated experimentally using an impedance tube. The key factors affecting the transmission loss are analyzed. The theoretical calculation results of the transmission loss of the side outlet muffler are in good agreement with the experimental results.

Model Analysis and System Parameters Investigation for Transient Wave in a Pump–Pipe–Valve System

The frequency responses of the transient wave propagating in a pump–pipe–valve system are studied with the system transfer matrix analysis (STMA) method. Being different to that in the reservoir–pipe–valve system, the transient wave is used as a long-distance communication technology in the pump–pipe–valve system, and very few works have been done on the model analysis and strategies to control the behavior of the oscillation signal of the pipe pressure. The theoretic solutions are studied with three internal friction models: frictionless, steady friction, and unsteady friction. The dimensionless parameter of the valve signal intensity (VSI) is proposed, and it is found to be a key factor affecting the quality of the wave propagation in the pipe. A larger pressure oscillation at the upstream side results when the VSI is smaller than one, whereas a more uniform amplitude for the resonances and anti-resonances is obtained when VSI approaches one. Some feasible suggestions are provided to obtain high quality wave signals.

Graded resonator arrays for spatial frequency separation and amplification of water waves

A structure capable of substantially amplifying water waves over a broad range of frequencies at selected locations is proposed. The structure consists of a small number of C-shaped cylinders in a line array, with the cylinder properties graded along the array. Using linear potential-flow theory, it is shown that the energy carried by a plane incident wave is amplified within specified cylinders for wavelengths comparable to the array length and for a range of incident directions. Transfer-matrix analysis is used to attribute the large amplifications to excitation of local Rayleigh–Bloch waves and gradual slowing down of their group velocity along the array.

Transfer Matrix Analysis for Curved Beam Structure

The curved beam structure such as pipe system has been widely used in industrial plants or power stations. In this study, the reduction technique of stiffness matrix, which is refered to “transfer matrix method (TM)“, is developed to solve effectively the problem. For achieving the purpose, the transfer matrix Fk to transfer deformation, rotation, force and moment from node i to node i+1, which are named for both edges in k-th beam element, is formulated. The global transfer matrix is then constructed by multiplying as R(θk+1,k)·Fk···R(θ2,1)·F1···R(θk+1,k) is the coordinate rotation matrix. The efficiency and simplicity of this method is demonstrated by solving the problem of a curved pipe line with elbow which is subjected to external forces and displacements. The results are compared with those obtained by FEM.

Simulating and optimizing compound refractive lens-based X-ray microscopes

A comprehensive optical description of compound refractive lenses (CRLs) in condensing and full-field X-ray microscopy applications is presented. The formalism extends ray-transfer matrix analysis by accounting for X-ray attenuation by the lens material. Closed analytical expressions for critical imaging parameters such as numerical aperture, spatial acceptance (vignetting), chromatic aberration and focal length are provided for both thin- and thick-lens imaging geometries. These expressions show that the numerical aperture will be maximized and chromatic aberration will be minimized at the thick-lens limit. This limit may be satisfied by a range of CRL geometries, suggesting alternative approaches to improving the resolution and efficiency of CRLs and X-ray microscopes.

OPTICAL BISTABILITY CONTROLLED USING ADD-DROP MOBIUS MICRORING RESONATOR SYSTEM

The theoretical investigation has been performed on the implementation of optical Mobius shape in add-drop microring resonator. The modified add-drop Mobius configuration is used to investigate the optical bistability and the spectral transmission. The optical bright soliton pulse is used as the input source of the resonator system. The pulses propagation of the resonator system is modelled using the iterative programming based on the transfer matrix analysis equations. The enhancement of nonlinear effect of the resonator system is achieved by the add-drop Mobius resonator configuration. The system has been modelled for a variation of coupling coefficient for increase the bistable signal properties. The Add-drop Mobius MRR generated a bistable signal with 6.01 mW hysteresis width, and 9.47 mW output switch power with optimized radius of 5 µm outer and 4.5 m inner ring parts with 50 mW controlled power and input power. Mobius configuration is found as the better shape of resonator cavity that capable of optical switching application.