near field pressure 中文意思是什麼
near field pressure
解釋
近場壓力-
First, it was taken that a discuss about the effects of geometry parameters of each piezocrystal on direction parameters ( main lobe width, side lobe amplitude, elimination of grating lobes ), amplitude of ultrasonic pressure, element viberation pattern, mutual radiation among elements, efficient test regions, ability to keep accurate and near - field distance and so on. based on the direction of ultrasonic field in ulpa deduced by ourselves. in addition, on the base of integrating all kinds of factors, it was put forward that the principle and method for optimized design of geometry parameters of piezocrystals in ulpa transducer, and its design programme and interface were compiled
首先在推導超聲相控線陣換能器聲場的指向性的基礎上，就各個晶片幾何參數對指向性指標（主瓣寬度、旁瓣幅度、消除柵瓣） 、聲壓幅值、陣元振動模式、陣元間互輻射、有效檢測區域、精確控制能力、近場長度等方面的影響進行了論述，並在綜合各方面影響的基礎上，提出了晶片幾何參數優化設計的原則和方法，編寫了設計程序和界面。 -
In this paper, high heat penetration into a moving particulate bed is described mathematically with a comprehensive heat and mass transfer model. the distribution of gas velocity and pressure, the temperature field of gas and solid in the moving particulate bed are examined for different conditions. the results show that thermal penetration into the moving packed - bed particles by fluid flow in porous media is high only in the position near the gas entrance. the thermal penetration thickness tends to increase with the fluid flow velocity and decrease with the particle moving velocity. in the region of thermal penetration, the porosity of solid bed has significant effect on gas field and pressure loss. it is feasible to reduce the gas pressure loss by a larger width / height packed bed in design and operation. the correspondence between thermal infection depth and particle bed height would be helpful to keep high oapacity of reactor and reduce the cost of operation
針對移動顆粒床中物料層內的高溫氣體滲流傳熱現象，考慮滲流與傳熱的相互作用，採用局部非熱平衡假設建立了多孔介質滲流傳熱物理數學模型並進行了數值計算.研究了不同情況下床內填充多孔介質中的流速、氣固溫度和床層壓力損失.計算結果表明，高溫熱氣對移動床顆粒料層的熱滲透主要發生在滲流入口端區域，增大入口滲流速度以及減小床層物料下移速度將導致物料溫度沿床高慢速下降，熱滲透深度擴大，熱滲透作用區域內的物料溫度水平提高.在熱滲透作用區域，孔隙率對流場和壓力損失有很大的影響.研究結果對于移動顆粒床反應器的設計與運行具有一定的參考作用 -
Focusing on the problem of sound field of scattering due to the existence of tubes, the general mathematical model modeled according the condition of plant, and then the coefficient of sound scattering is resolved by using the method of inverse matrix, the functions of arbitrary configuration of tubes is got, the far field scattered pressure and near field scattered intensity of the unit of heat exchanger tubes is calculated, at last, the effect of soot cleaning due to the existence is analyzed
論文根據爐內管束的實際情況，建立換熱器管束聲波散射的通用數學模型，利用迭加原理法求解模型中的待定散射作用系數，得出任意布置管束的散射聲場特性，並具體計算鍋爐換熱器管束單元聲波散射遠場聲壓分佈和近場壁面的聲強分佈，最後分析由於聲波的多重散射作用而對聲波吹灰的影響。 -
Conjugate heat transfer calculation was carried out, with simple algorithm, studied up on boundary condition and modified pressure adapting algorithm, to give prediction on velocity field inside the disk cavity, the whole temperature field including fluid region and solid region, and heat transfer coefficient at fluid - solid interface. the simulation results indicate, ( 1 ) in rotor - stator disc cavity, the secondary flows near rotating disc stronger than which near state disc, keeps temperature of rotating disc lower than state disc ' s
為了使計算方法得到更多的算例驗證，本次研究做了若干算例，文中選出其中四個算例進行分析，計算結果表明： （ 1 ）在轉靜盤腔結構中，轉盤表面的二次流大部分區域都比靜盤表面的要強，所以轉盤表面換熱情況較好，轉盤的總體溫度水平要低於靜盤。 -
When the intensity of the laser field is weak, the velocity dependence of the average longitudinal force has the doppler shifted lorenztian resonance. at high intensities, there is a kink and change direction of the light pressure force near the point of zero velocity, the effects of the higher order harmonic light pressure forces become significant
當激光場強度比較弱時，作用在原子上的力為洛侖茲型，隨著激光強度的增加，依賴于速度的零階力在零速度附近方向發生了反轉，出現了扭結現象。
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