海面太阳耀光背景下的偏振探测技术

为了实时抑制太阳耀光对海面目标探测的影响,基于偏振光学理论,设计并构建了一套偏振自适应滤波探测系统。本文介绍了偏振探测系统的功能和组成、偏振探测及背景抑制原理,并给出了该系统的光学设计结果;利用自适应偏振滤波探测系统,通过搭载望远镜跟踪试验平台,针对海上典型目标,开展了相关的偏振验证实验。实验结果表明:海面太阳耀光存在比较明显的偏振特性,采用常规探测手段,探测器极易出现饱和,而利用偏振探测技术则能够有效抑制太阳耀光的影响,进而实现目标的有效探测。     

全天候海冰气象监测系统可靠性研究

目的】为了减少海冰对平台生产所造成的影响,JZ9-3海域首次引用了全天候海冰气象监测系统。为了确保系统的正常运行,需要对系统进行可靠性评估。【方法】采用动态模糊故障树法,对全天候海冰气象监测系统的可靠性进行评估,同时提出初步的预防措施。【结果】通过应用动态模糊故障树对系统可靠性进行评估,获取了系统的薄弱环节,并提出了有效措施对薄弱环节加以控制。【结论】通过研究,有效地提高了系统的可靠性,这也是动态模糊故障树在国内的首次应用,为未来动态模糊故障树的广泛应用奠定基础。     

海表面流场微波遥感研究进展及其关键技术问题分析

海表面流场是海洋学中十分重要的研究对象,本文综述了海表面流场微波遥感所涉及的海表面建模、计算电磁学、合成孔径雷达(synthetic aperture radar,SAR)海面成像及SAR信号等基础研究领域,梳理了海表面流场微波反演的研究进展,分析了目前已有反演方法的利弊并找出待研究的科学问题,逐一剖析这些问题并提出解决方法。针对海表面流场微波遥感中有待解决的在动态海表面建模中如何引入海表面流场因素、运动海面电磁散射特征的表征中如何选取参数和反演过程中需要注意的图像分辨率等问题,提出了研究策略,指明了海表面流场微波遥感的技术路线和研究方向,最后对海表面流反演工作进行了展望,探讨了高分辨率海流反演的下一步工作。     

基于遗传神经网络算法的海面风速反演新方法

针对海面运动的复杂性、海面电磁散射理论模型的局限性以及利用SAR图像反演海面风速存在的非线性现象,基于遗传神经网络的方法,以业务化的CMOD4模式函数数据为基础,采用Fletcher-Reeves算法的变梯度反向传播算法,建立一种SAR风速反演的新模型。试验结果表明,利用遗传神经网络方法反演海面风速是可行的,当随机误差小于10%时,模型的抗噪能力较强,风速反演的精度较为理想。比较不同风速下的反演结果可以发现,在中、小风速的情况下,模型的抗噪能力较强,模型学习拟合和预测检验的精度相对较高;在大风速的情况下,模型的反演能力有待于进一步提高。     

Microwave-Assisted Desulfation of the Hemolytic Saponins Extracted from Holothuria scabra Viscera

Saponins are plant and marine animal specific metabolites that are commonly considered as molecular vectors for chemical defenses against unicellular and pluricellular organisms. Their toxicity is attributed to their membranolytic properties. Modifying the molecular structures of saponins by quantitative and selective chemical reactions is increasingly considered to tune the biological properties of these molecules (i) to prepare congeners with specific activities for biomedical applications and (ii) to afford experimental data related to their structure–activity relationship. In the present study, we focused on the sulfated saponins contained in the viscera of Holothuria scabra, a sea cucumber present in the Indian Ocean and abundantly consumed on the Asian food market. Using mass spectrometry, we first qualitatively and quantitatively assessed the saponin content within the viscera of H. scabra. We detected 26 sulfated saponins presenting 5 different elemental compositions. Microwave activation under alkaline conditions in aqueous solutions was developed and optimized to quantitatively and specifically induce the desulfation of the natural saponins, by a specific loss of H₂SO₄. By comparing the hemolytic activities of the natural and desulfated extracts, we clearly identified the sulfate function as highly responsible for the saponin toxicity.     

Analysis of Corrosion Products Formed on Cu-Ni Alloys Immersed in Sea Water

Abstract

A method was developed for separation and analysis of corrosion products formed on the surface of Cu-Ni alloys immersed in sea water polluted by sulphide ions. This method is based on the selective dissolution of oxidation compounds by suitable solvents dissolving the metal matrix only to a negligeable extent.

The following solvents were used: 1) methanol to dissolve Na⁺, Cu²⁺, Ni²⁺ chlorides and sulphates; 2) glycine to dissolve bivalent metal compounds - Cu²⁺, Ni²⁺ oxides, sulphides, oxysulphates, oxychlorides and oxycarbonates; 3) ammonia solution to dissolve Cu⁺ compounds (i.e. Cu₂O and CuCl); 4) potassium cyanide to dissolve CU⁺ sulphides.

Reasonable agreement between chemical and X-Ray analysis results was observed only for copper compounds, since nickel and iron compounds could not tie observed by X-Ray diffraction. The results of Auger and chemical analyses better agree with each other, yet no Fe compounds could be detected. This is to be attributed to the non-homogeneous corrosion layer which notably contains Fe compounds in the innermost region at a depth where Auger spectroscopy is unable to detect them, whereas their detection is possible by chemical analysis, since it is a bulk analysis.     

毛细管气相色谱法测定深海鱼油中的EPA和DHA含量

用氢氧化钾－甲醇酯化法将深海鱼油中的脂肪酸快速、有效地转化成脂肪酸甲酯,然后进行毛细管气相色谱法测定,以二十二碳饱和脂肪酸甲酯为内标物,建立了5,8,11,14,17－二十碳五烯酸（EPA）和4,7,10,13,16,19－二十二碳六烯酸（DHA）的定量分析方法,并用于实际样品分析。该方法对EPA和DHA定量分析的相对标准偏差分别为4．6％和5．0％,回收率分别为99．7％和99．4％。     

建模思想在化学原理教学中的运用

通过竞争反应与海水晒盐2个案例,阐述了在化学原理教学过程中运用建模思想,可以使复杂的过程变得简洁、抽象,从而明晰现象背后的原理、规律。