防覆冰涂层构建机理及制备

航空、通信、电力和运输设备的覆冰现象给人们的生产、生活带来许多不便,甚至引起重大经济损失,防覆冰涂层主要通过材料表面特殊物理化学性能与微相形貌来实现抗冰目的,这类材料需要兼具防结冰性和疏冰性,从延长结冰时间和降低冰的附着力两方面来减轻甚至消除冰雪积聚,是目前研究的热点。本文从防覆冰机理入手,深入探讨了防结冰性和疏冰性的影响因素,阐述了防覆冰涂层材料的设计与制备方面的最新进展,并对防覆冰涂层目前存在的问题与发展方向进行了分析和展望。     

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％。     

DX-300离子色谱测定山地冰川雪冰中的有机酸与无机酸阴离子

 利用AS4A SC分离柱 ,AG4A SC保护柱 ,ASRS Ⅱ抑制器 ,TAC 2阴离子富集柱和ATC 1阴离子捕集柱 ,以四硼酸钠 (Na2 B4O7)为淋洗液试剂 ,2 5mmol/LH2 SO4为化学抑制的再生液 ,采用梯度淋洗方式 ,对中国天山乌鲁木齐河源一号冰川雪冰中的生物有机酸和无机酸阴离子进行了测试分析。 2mL雪冰融水样品可在 16min内通过一次进样检测出氟离子、乙酸根离子、甲酸根离子、丙酮酸根离子、一氯乙酸根离子、氯离子、亚硝酸根离子、溴离子、硝酸根离子、磷酸根离子、硫酸根离子和草酸根离子共 10多种有机酸和无机酸阴离子。     

海冰动力学数值模拟中改进的PIC方法

为了准确地模拟海冰的动力过程,需要建立精确有效的数值方法。本文结合质点网格法(PIC)和光滑质点流体动力学方法(SPH)发展了一种改进的PIC方法。该方法在欧拉坐标下对海冰动量方程进行差分计算,在拉格朗日坐标下进行海冰质点位移、厚度和密集度计算,并采用Gauss函数进行欧拉网格点与拉格朗日质点间海冰参数的交互插值。采用改进的PIC方法对规则区域内的海冰堆积过程进行了数值试验,对渤海海冰的动力过程进行了72小时数值模拟。计算结果均表明改进的PIC方法具有计算量小,计算结果平稳精确的优点,可很好地适用于海冰动力作用过程的数值模拟。     

高分辨电感耦合等离子体质谱仪测定中亚山地冰川雪冰中超痕量元素

在超净实验条件下,利用高分辨电感耦合等离子体质谱仪直接测定雪冰样品中浓度在1ng/L~100μg/L之间的多种超痕量元素Al、Fe、Mn、Co、Cu、Zn、Sr、Sb、Cd、CsBa、Tl、Pb和Bi的实验方法进展。在测定过程中灵敏度的变化可通过监测ArAr质谱峰的变化进行校正,并建立了数学校正公式。以1%HNO3为空白溶液获得了各元素的检出限(ng/L)分别为:Al40、Mn6、Fe40、Co2.74、Cu9.6、Zn20、Sr0.03、Sb0.15、Cs0.04、Ba0.4、Tl0.07、Pb0.8和Bi0.05。利用标准参考物质SLRS-4对测试方法的准确度进行了评价。研究了在硝酸含量分别为0.5%、1%、2%和4%时雪冰中超痕量元素质谱信号强度的变化特点。测定结果发现,对于污化层样品,当硝酸的含量为1%时痕量元素的质谱信号强度最大;对于非污化层样品,痕量元素的质谱信号强度在硝酸含量为0.5%时较大,但与硝酸含量为1%时的质谱信号强度相比变化率小于10%。结合中亚山地冰川雪冰中痕量元素浓度差别大的特点,确定硝酸在样品中的含量为1%为合适的酸度。并对卓奥友峰和珠穆朗玛峰雪坑样品进行了分析方法的重复性研究。     

First report of the nutritional profile and antioxidant potential of Holothuria arguinensis,a new resource for aquaculture in Europe

This work reports for the first time the nutritional profile and antioxidant potential of the edible sea cucumber Holothuria arguinensis from the North-eastern Atlantic. H. arguinensis has high levels of protein, with the amino acids profile dominated by alanine, glycine and proline and low lysine/arginine ratios. Its carbohydrate and energetic contents are also low as well as the total lipid levels, although its lipid profile is rich in polyunsaturated fatty acids (PUFA), especially arachidonic, eicosapentaenoic and docosahexaenoic acids. In addition, H. arguinensis has high levels of calcium. The water and ethanol extracts show ability to scavenge free radicals and to chelate copper and iron ions. Our results indicate that H. arguinensis has a balanced nutritional quality suitable for human consumption. In addition, it contains compounds with antioxidant potential; thus its intake can contribute for a healthy and well-balanced diet.     

热带太平洋海平面年际和年代际变化研究进展

回顾热带太平洋对海平面长期趋势有重要影响的海平面年际和年代际变化的相关研究,总结包括近期提出的中部型厄尔尼诺在内的2种类型厄尔尼诺对热带太平洋海平面年际变化的影响,揭示了热带太平洋海平面年代际变化与信风年代际变化之间的紧密联系。指出赤道信风的增强对近期热带太平洋海平面变化格局的形成有决定性作用,厄尔尼诺强度的减弱对这种格局有贡献,而拉尼娜的影响有待深入研究。研究资料的局限性导致年代际变化的定量研究成果较少,在研究海平面年际和年代际变化时应用的热通量评估模型有待改进。     

北方航线的综合评价研究

考虑航线评价中的多种因素及其影响程度的不同,从安全和经济的角度出发,采用模糊综合评判方法对北方航线进行航线优劣程度评价.     

Determination of Cadmium and Lead in Sea Water after Extraction Using Electrothermal Atomisation. Minimisation of Interferences from Co-Extracted Sea Salts

Abstract

Interferences from small amounts of sea salt in the determination of cadmium and lead were investigated. Test samples were made to mimic solutions obtained after extraction of sea water for trace metal analysis. Sea salt concentrations in the range 0–400 mg/l were investigated. Background absorption from this salt was high but easily minimised through the addition of nitric acid (2 % v/v). Sensitivity reductions due to the salt were considerable and varied from one graphite tube to the other. This problem was overcome by the addition of 1000 mg lanthanum per litre of sample. The positive effect of the lanthanum matrix modification is thought to be due to a change of the graphite tube surface.     

Molecular dynamics study of ice structural evolution

Molecular dynamics simulation is employed to study the structural evolution of low density amorphous ice during its compression from one atmosphere to 2.5 GPa. Calculated results show that high density amorphous ice is formed at an intermediate pressure of -1.0 GPa; the O-O-O bond angle ranges from 83° to 113°, and the O-H… O bond is bent from 112° to 160°. Very high density amorphous ice is obtained by quenching to 80 K and decompressing the ice to ambient pressure from 160 K/1.3 GPa or 160 K/1.7 GPa; and the next-nearest O-O length is found to be 0.310 nm, just 0.035 nm beyond the nearest O-O distance of 0.275 nm.