水下透明度計 的英文怎麼說
中文拼音 [shuǐxiàtòumíngdùjì]
水下透明度計
英文
underwater transparency meter- 水 : 名詞1 （由兩個氫原子和一個氧原子結合而成的液體） water 2 （河流） river 3 （指江、河、湖、海、洋...
- 下 : 下動詞1. （用在動詞后,表示由高處到低處） 2. （用在動詞后, 表示有空間, 能容納） 3. （用在動詞后, 表示動作的完成或結果）
- 透 : Ⅰ動詞1 （滲透; 穿透） penetrate; pass [seep] through 2 （暗地裡告訴） tell secretly; let out; lea...
- 明 : Ⅰ形容詞1 （明亮） bright; brilliant; light 2 （明白;清楚） clear; distinct 3 （公開;顯露在外;不隱...
- 度 : 度動詞[書面語] （推測; 估計） surmise; estimate
- 計 : Ⅰ動詞1 （計算） count; compute; calculate; number 2 （設想; 打算） plan; plot Ⅱ名詞1 （測量或計算...
- 透明度 : 1 （透過光線的程度） pellucidity; transparency; transmittance; diaphaneity2 （政治方面的公開程度...
- 透明 : transparent; vifrification; hyaline; diaphaneity; lucency
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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But, though considerable process has been made in the last ten years, digital watermarking is still in its infancy, and much interesting work remains to be done this thesis addresses some problems in the gray - scale image digital watermarking that are summarized below : 1 ) whereas the basic theory of digital watermarking is still very poor, a digital watermarking mathematic model based on imperceptibility and robustness is presented by analysising the characteristic of digital watermarking ; 2 ) based on the model constructed above, by defining the measures of capacity and robustness of digital watermarking, an objective method for evaluating the digital watermarking is introduced and used to analysis some algorithms ; 3 ) whereas geometric distortion always influences the restoration of watermark, we advocate to enhance the robustness against geometric distortion by restoring the image which has been distorted by geometric transformation, and a method is designed for estimating the parameters of geometric transformation ; 4 ) based on the conclusion discussed above, and combined with the masking effects of hvs, a novel public meaningful gray - scale image digital watermarking is designed by analysising the characteristics of image gray - scale interpolation and haar wavelet transformation. the experimental results show that the method is indeed powerful ; 5 ) whereas many image digital watermarking schemes, which embed watermark by modifying the values of pixels in spatial domain and transformed domain, are confronted with the conflict between the imperceptibility and robustness, we advocated to use some stable digital characteristics of host image as watermark and a algorithm based on hermite matrix is designed
本文重點對灰度圖象數字水印技術進行研究，主要工作如下： 1 ）鑒于目前數字水印的理論研究比較薄弱的現狀，本文通過分析數字水印的特點，建立了一個數字水印的數學模型，為進一步研究數字水印打下了基礎； 2 ）根據以上建立的模型，通過引入容量和穩健度的概念為數字水印提供了一個客觀評價方法，並對一些數字水印演算法進行了分析； 3 ）為增強數字水印抵抗幾何攻擊的能力，研究了受幾何攻擊的圖象的復原問題，並給出了一個計算圖象幾何變換參數的方法； 4 ）通過分析圖象灰度插值演算法和haar小波變換的特點，結合hvs的掩蔽效應，設計了一個公開的有意義數字水印演算法，實驗結果表明本演算法具有較強的穩健性； 5 ）目前許多水印演算法都是通過在空域或頻域修改象素值的方法嵌入水印的，這種方法面臨著透明性和穩健性的矛盾，為解決這個矛盾，本文提出以圖象的某些穩定的數字特徵為水印的觀點，並結合hermite矩陣的特點設計了相應的水印演算法，實驗結果表明該演算法具有較好的穩健性。
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