海水中不同盐分对水下光传输影响的研究

发布时间：2018-01-07 15:27

本文关键词：海水中不同盐分对水下光传输影响的研究　出处：《河南师范大学》2016年博士论文　论文类型：学位论文

【摘要】：由于海水中不仅含有各种千奇百怪、大小不等、形状不一、结构不同的有机物质,还含有大量的无机物质,而且所有物质都是随机分布的。因此光在海水中的传播比在空气中传播时复杂得多。海水对光的衰减主要包括两个方面:海水对光的吸收和海水对光的散射。海水的衰减系数是海洋环境健康状况的晴雨表,也是评价水下通信质量的重要指标之一。鉴于此背景,研究海洋中各种物质对光传输的影响,以及研究分析其产生的机理对水下激光通信、海洋光学遥感、环境监测以及海洋水文勘察等许多领域都有着十分重要的意义。本文从光在海水中的吸收效应和散射效应两个方面入手,对海水中主要无机海盐水溶液的光学性质进行了深入研究。主要包括以下几个方面:首先,为了弄清海水对光散射、吸收的机理,本文从离子水合的微结构出发,依据量子分子动力学理论,采用溶剂化模型,研究海水中不同离子的水合过程,掌握不同离子的水合结构,并在此基础上采用基于瑞利散射理论的离子散射模型结合密度起伏理论研究了极稀海水中不同盐分对光散射的影响。采用该方法对海水光散射的研究尚属首次。其次,采用实验方法,详细阐述了海水中不同盐分在可见光波段对光的吸收特性影响,并建立了电导率与吸收系数关系的经验模型。在该研究中我们发现,镁盐不同于钠盐和钾盐,具有更为特殊的光学特性,值得进一步的探讨和深入研究。再次,通过实验观测磁场作用下离子水合结构的各项异性,揭示了磁场环境对海水中不同盐分的光学特性影响机理。实验结果表明,当采用不同偏振方向的入射光时,在相同浓度相同磁场强度下,经磁场磁化作用后的溶液的透射率在不同方向上呈现明显差异,采用P偏振光得到的透射率总是大于采用S偏振光得到的透射率;溶液浓度越大,其透射率越低;当入射光为P偏振光时,磁场的强度越强,磁处理后的溶液的透射率越大;但当入射光为S偏振光时,磁场的强度越强,磁处理后的溶液的透射率却越低。通过分析纯水和不同盐分水溶液的中红外光谱发现,磁场改变了水的红外吸收性质,纯水的红外光谱吸收强度随磁场强度的增大而增加。尽管如此,磁场仅仅使纯水的吸收峰强度增加了,却并没有改变峰的位置。换言之,随着磁场强度的增加,水分子的极化特性和分子偶极矩增大,分子磁矩发生改变,但水的分子结构并没有发生改变。对不同盐分溶液而言,随着磁场的增强,O-H带宽宽度增加,吸收峰位置向低波数移动,盐离子对水具有明显的结构破坏效应;相比氯盐对水分子结构的影响,硫酸盐对水分子结构的影响更大,并且不同盐分溶液的红外吸收光谱也反映出溶液中阳离子和阴离子对水分子结构的扰动状况。最后,利用阻抗分析仪实验研究了磁场对不同海盐水溶液电导率的影响。通过研究分析,我们拟合出了关于浓度与电导率的经验关系式,该式子不仅适用于低浓度溶液,也适用于高浓度溶液。不仅如此,新建的关系式既适用于磁化溶液,又适用于未磁化溶液。另外,通过分析发现,磁场对电导率的影响在一定程度上是由于离子周围水合层厚度及水分子分布的变化引起的,这种变化也导致了水合半径发生了变化。该发现为进一步开展水下磁性目标探测等探索一种新途径、新方法,同时也为海洋水文监测等相关领域提供一定的科学依据。目前,有关海水光学性质的研究主要通过理论模拟和实验的方法,而且实验研究特别是实地观测的方法具有很大的地域局限性,另外很少有从离子水合等微观机理上来研究和分析海水的光学现象。本文采用离子散射的概念,针对海水中的几种主要盐分对光散射的影响进行了研究,与采用分子散射模型研究海水的光散射相比,在淡海水中该新建模型具有更好的适用性;拟合出了可见光波段吸收系数与电导率的经验关系式,而且该关系式对各种无机盐水溶液具有普适性,为下一步进行理论研究提供参考;拟合出了不仅适用于低浓度溶液,也适用于高浓度溶液;既适用于磁化溶液,又适用于未磁化溶液的关于浓度与电导率新的关系式,为进一步开展水下磁性目标探测等探索一种新途径、新方法。
[Abstract]:Because the water contains not only a variety of all sorts of strange things, sizes, shapes, different structures of organic matter, also contains a large number of inorganic substances, and all substances are randomly distributed. Therefore light propagation in seawater is spread in the air is much more complicated. The sea optical attenuation mainly includes two aspects the scattering of the light absorption and light water on water. The attenuation coefficient of seawater is a barometer of the health of the marine environment, is an important indicator of evaluating communication quality under water. In view of this background, studies the influence of various substances in the ocean of light transmission, and analysis of the mechanism of underwater laser communication. Marine optical remote sensing, has a very important significance in many fields of environmental monitoring and marine hydrographic survey. This paper from two aspects in the light in the water absorbing and scattering effect of the sea The optical properties of inorganic salt aqueous solution is mainly studied. Mainly includes the following aspects: first, to clarify the water absorption of light scattering, the mechanism of the micro structure of ion hydration, based on quantum molecular dynamics theory, the solvation model, study the hydration process of different ions in seawater, grasp the hydrate the structure of different ions, and on the basis of the ion scattering model of Rayleigh scattering theory based on the combination of density fluctuation theory to study the dilute seawater salinity on the light scattering effect. Using the method of light scattering in sea water is the first. Secondly, using the experimental method, the effects of different salt water in characteristics the light absorption of visible light is elaborated, and the establishment of the empirical model of the relationship between conductivity and absorption coefficient. In this study, we found that different from sodium salt and magnesium salt Salt, has more special optical properties, is worth further study and research. Thirdly, through experimental observation field anisotropy of ion hydration structure, mechanism of effect of magnetic field on the optical properties of different salts in seawater was revealed. The experimental results show that when the incident light with different polarization direction, at the same the same concentration of magnetic field intensity, the transmittance of magnetic solution after the role of the obvious difference in different directions, with the transmittance of P polarized light is always greater than the transmittance obtained by S polarized light; the greater the concentration of the transmittance is lower; when the incident light is P polarized light, the strength of the magnetic field is stronger, the transmittance of the solution after the magnetic treatment increases; but when the incident light is S polarized light, the stronger the magnetic field, the magnetic treatment solution transmittance decreased. Through the analysis of pure water and different salt In aqueous solution of infrared spectroscopy, magnetic field changes the water absorption properties of infrared, infrared spectra of pure water absorption intensity increases with the increase of magnetic field intensity. However, only the water absorption peak of the magnetic field strength increases, but does not change the position of the peak. In other words, with the increase of magnetic field intensity, moment the polarization characteristics and molecular dipole water molecules increases, the molecular moment changed, but the molecular structure of the water did not change. The different salt solution, with the increase of the magnetic field, O-H band width increased, absorption peak shifted to low wave number, salt ions have obvious damage effect of structure on the water; compared to the impact of chlorine salt of water molecules, effect of sulfate on the molecular structure of water is greater, and the infrared absorption spectra of different salt solution also reflects the cations and anions in solution of disturbance of the molecular structure of water. Finally, study the influence of magnetic field on different salt water solution conductivity by using an impedance analyzer experiment. Through research and analysis, we made empirical formula on concentration and conductivity of the fitting formula is not only suitable for low concentration solution, also suitable for high concentration solution. Moreover, the new formula is suitable for magnetizing solution. It is suitable for unmagnetized solution. In addition, the analysis found that the effect of magnetic field on the conductivity to a certain extent is due to ions and water molecules around the hydrate layer thickness distribution changes, this change has led to changes in the hydration radius. This discovery to explore a new way for the further development of underwater magnetic target a new detection method, but also provide a scientific basis for the field of marine hydrological monitoring. At present, the research on the optical properties of seawater mainly through theoretical simulation and real Experimental methods and experimental research, especially the field observation methods with regional limitations, in addition there are few up from the microscopic mechanism of ion hydration research and analysis of seawater optical phenomena. This paper uses the concept of ion scattering, aiming at several main salt in seawater on light scattering was studied, compared with the molecular scattering model of seawater light scattering, the applicability of the new model has better light in seawater; fitted empirical formula of visible light absorption coefficient and conductivity, and the relation between the universality of various kinds of inorganic salt solution, provide reference for theoretical research for the next step; fitting that is not only suitable for low concentration solution, also suitable for high concentration solution; which is not only suitable for the magnetization solution, and is suitable for non magnetized solution on the relationship between concentration and conductivity as a new. A new approach and a new method for exploring the underwater magnetic target detection step by step.

【学位授予单位】：河南师范大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P733.31;TN929.3

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