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海洋污损生物防除技术和发展(Ⅲ)——世界防污技术的历史和发展 总被引:4,自引:0,他引:4
本讲总结了船舶防污技术的历史发展过程和方向,包括最早的船体包覆铜皮技术,铜化合物防污漆,有机锡高聚物自抛光防污漆,无锡铜基自抛光防污漆,以及其它一些无毒防污漆,如低表面能防污漆,导电防污漆和生物防污技术等。 相似文献
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海洋生物污损是制约船舶业发展的重要问题。人们很早就开始对防污方法进行研究并先后采用机械除污法、涂覆防污涂料法、表面改性法等去除海洋附着生物。综述了船舶防污方法及其研究进展,通过分析各种防污方法的特点,指出了存在的问题,并对未来船舶防污的发展前景进行了展望。 相似文献
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防污涂料与船舶的航行经济效果密切相关。国内外船舶涂料界正从各种技术角度研究着新防污涂料。下边就防污涂料的现状与未来作一介绍。 1.海洋生物的污损及其防止方法生物污损可分为藤壶等的动物性污损和藻类等的植物性污损。整个附着污损过程是很复杂的。而防污方法的着眼点,就是选择一个切断其生长的环节。今后,一方面要不断完善过去使用的毒物溶出的方法,另一方面,要研究“不使生物附着的方法”。防污方法的基本原理如下: 相似文献
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Ryohei Tanaka 《Materials at High Temperatures》2013,30(4):237-238
An encapsulation technique for high-temperature controlled-environment testing is introduced. This encapsulation technique is combined with the DC potential drop technique to monitor the crack growth during the experiment. This technique eliminates the complicated retort systems of conventional mechanical testing and possesses the advantages of compactness, transportability, ease of manufacture and low cost. Test results in vacuum using this technique are compared with results of similar experiments in air and in a retort system. 相似文献
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The technique introduced in this paper is a new technique for analyzing fault tolerant designs under considerable uncertainty, such as seen in unique or few-of-a-kind devices in poorly known environments or pre-prototype design analyses. This technique is able to provide useful information while maintaining the uncertainty inherent in the original specifications. The technique introduced here is a logical extension of the underlying concepts of fuzzy sets and Markov models. Although originally developed for robotic systems, the technique is more broadly applicable. This paper develops fuzzy Markov modeling and uses it to analyze a specific robot designed for hazardous waste removal and specific types of electronic systems. 相似文献
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Seelamantula CS Villiger ML Leitgeb RA Unser M 《Journal of the Optical Society of America. A, Optics, image science, and vision》2008,25(7):1762-1771
We address the problem of tomogram reconstruction in frequency-domain optical-coherence tomography. We propose a new technique for suppressing the autocorrelation artifacts that are commonly encountered with the conventional Fourier-transform-based approach. The technique is based on the assumptions that the scattering function is causal and that the intensity of the light reflected from the object is smaller than that of the reference. The technique is noniterative, nonlinear, and yields an exact solution in the absence of noise. Results on synthesized data and experimental measurements show that the technique offers superior quality reconstruction and is computationally more efficient than the iterative technique reported in the literature. 相似文献
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Watt DW 《Applied optics》1994,33(20):4420-4427
A tomographic reconstruction algorithm similar to the well-known algebraic reconstruction technique (ART) is presented. Similar to ART, the approximate algebraic reconstruction technique (AART) technique consists of a sequence of displacements of the image vector based on the projection error. AART is a column-relaxation technique that is a series of vector displacements of the image vector parallel to its coordinate axes. AART is compared with ART, a standard conjugate-gradient technique, and a conjugate-gradient technique augmented by nonnegativity. The use of relaxation parameters to improve the performance of both ART and AART in the presence of noise is discussed, and the use of an iteration termination criterion based on random generalized cross validation is illustrated. 相似文献
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Michael Macri Andrew Littlefield 《International journal for numerical methods in engineering》2013,93(11):1147-1169
This paper details a novel new multiscale technique for modeling heterogeneous materials undergoing substantial thermal stresses. The technique is based on an enriched partition of unity approach that incorporates the thermal effects occurring on the microstructure into the global model. We demonstrate the effectiveness of this technique by implementing it into both the standard finite element method and the octree partition of unity method (OctPUM). The results demonstrate that the technique has uniquely improved accuracy over the homogenization method conditional to the method into which it is implemented in. The multiscale technique, when implemented into either the standard finite element method or OctPUM, increases the accuracy of the strain energy calculation. When the multiscale technique is implemented into OctPUM, it also is able to capture the unique stress fields on the microstructure of the model. Published 2012. This article is a US Government work and is in the public domain in the USA. 相似文献
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A quantitative autocalibrated high-resolution schlieren technique for quantitative measurement of reflective surface shape is proposed. It combines the schlieren principle with the phase-shifting technique that is generally used in interferometry. With an appropriate schlieren filter and appropriately tailored setup, some schlieren fringes are generated. After application of the phase-shift technique, the schlieren phase is calculated and converted into beam deviation values. Theoretical and experimental demonstrations are given. The technique is validated on a reference target, and then its application in a fluid physics experiment is demonstrated. These two examples show the potential of the phase-shifting schlieren technique that in some situations can become competitive with interferometry but with a much better dynamic range and with variable sensitivity. The technique can also be used to measure refractive-index gradients in transparent media. 相似文献
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Prony's technique is used to estimate multipath parameters from range-gain patterns produced by ground multipath interference in line-of-sight radio links. The field distribution at the transmitting antenna side is obtained by digital reconstruction from the range-gain pattern that is recorded, at constant height, along ground surface. The technique is presented as a competitive alternative to the Fourier transform, where much shorter data windows are sufficient for the proposed technique. The technique is validated by calculated and measured range-gain patterns, and the predicted values are in good agreement with the actual ones. Prony's technique produced predictions with comparable errors to the Fourier technique from much smaller data windows. 相似文献
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对国内外电流脉冲加热技术的发展状况进行了综述评价.针对获取温度方法不同,主要介绍了黑体法、积分球法和激光偏振法三种基本形式的测量系统,进而介绍了扩展参数测量装置.又较为详细地介绍了作者自己研制的测量装置和特点.最后作者展望了电流脉冲加热技术的最新研究动态和发展方向. 相似文献
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A moiré pattern color-encoding technique in which a digital image-processing system is used is described. The technique can display color moiré patterns with color sequences that represent the fringe orders. This technique is simple and fast and can be performed automatically. Experimental results demonstrating the feasibility of the technique are reported. 相似文献