Effect of ZnF2 Coating on Performance of LiNi0.5Mn1.5O4 Cathode Material for Lithium-ion Batteries

采用溶胶-凝胶法制备了LiNi0.5Mn1.5O4正极材料，并利用Zn F2对其表面进行包覆改性。XRD、SEM和TEM测试表明，包覆处理不影响材料的晶体结构，2%(质量分数，以LiNi0.5Mn1.5O4质量计，下同)的Zn F2在LiNi0.5Mn1.5O4表面形成了约7 nm厚均匀包覆层。对未包覆的LiNi0.5Mn1.5O4和1%、2%、3%的Zn F2包覆后的LiNi0.5Mn1.5O4的电化学性能进行了考察，发现Zn F2包覆能够减弱电解液与LiNi0.5Mn1.5O4正极材料之间的相互作用，稳定电极表面，提高材料的电化学性能。其中，2%Zn F2包覆样品表现出最佳的循环性能和倍率性能，0.2C电流倍率下循环200圈后，其放电比容量维持在109.0 m A·h/g，保持率为79.7%；5 C电流倍率下循环500圈后，放电比容量维持在94.2 m A·h/g，保持率为85.6%

Fatty acid composition of three species of marine microalgae during growth phases

球等鞭金藻、盐藻和小球藻脂肪酸组成气相色谱分析的结果表明 ,三种海洋微藻在指数生长期总多不饱和脂肪酸含量 (TPUFA)明显比稳定生长期高 ,而总饱和脂肪酸含量 (TSFA)在指数生长期间相对较低。球等鞭金藻的DHA ,小球藻的EPA和盐藻的C18∶3均在培养后的第 6d均达最大值。GC determination of fatty acid composition of Isochrysis galbana, Chlorella sp. and Dunaliella salina showed that TPUFA of the three species of microalgae in exponential phase were higher than those in stationary phase, otherwise, TSFA were relatively lower in exponential phase. DHA of Isochrysis galbana, EPA of Chlorella sp. and C18∶3 of Dunaliella salina were all the maximum at sixth day during cultural period.国家自然科学基金资助项目 (39870 5 6 5 ) ;; 福建省自然科学基金资助项目 (C970 0 6

超声波对球等鞭金藻脂肪酸组成的效应研究

国家自然科学基金!39870565;;福建省自然科学基金!C9700

Effect of Irradiance of Fatty Acid Composition of Marine Microalgae

不同光辐射强度下三角褐指藻和小球藻脂肪酸的气相色谱分析表明 ,光辐射对海洋微藻脂肪酸的含量和组成影响很大。三角褐指藻和小球藻总多不饱和脂肪酸含量随着照度的增加呈下降趋势。在本实验条件下 ,在较低光强 (0 .2 5× 10 3 L ux～ 1.7× 10 3 L ux)时 ,EPA、DHA、C18∶ 3等多不饱和脂肪酸含量较高。The experiment indicates that the irradiance has a great effect of fatty acid composition of marine micro algae,fatty acids of the two species of marine and the contents of EPA, DHA,in p tricornutum and Chlorella sp Are declined with the increase of the irradiance, and the contents of EPA,DHA,C18∶3 are higher under lower light intensities国家自然科学基金资助项目 ( 39870 5 6 5 );; 福建省自然科学基金资助项目 ( C970 0 6

Effect of temperature on fatty acid composition of four species of marine microalgae

对在不同温度下培养的 4种海洋微藻脂肪酸的气相色谱分析表明 ,不同微藻的脂肪酸组成及其不饱和程度受温度影响的差别较大 .在本实验条件下 ,随着温度升高 ,球等鞭金藻、盐生杜氏藻、三角褐指藻的总多不饱和脂肪酸 (TPUFA)百分含量及脂肪酸平均双键数 (MDB)均呈下降趋势 ,其总单不饱和脂肪酸 (TMUFA)和总饱和脂肪酸 (TSFA)百分含量则呈增加趋势 ;随着温度提高小球藻TPUFA百分含量和脂肪酸平均双键数先降低后增加 ,在 2 0℃时出现最小值 .The experimental results indicated that the temperature had distinct effects on the composition and unsaturated degree of fatty acid of microalgae, on the basis of GC analysis of fatty acid of four species of marine microalgae. The percentages of TPUFA in TFA and the number of mean double-bond of fatty acids of Isochrysis galbana, Dunaliella salina and Phaeodactylum tricornutum decreased with the ascending temperatures, while those of TMUFA and TSFA increased under the condition of the experiment. The content of TPUFA and the number of mean double-bond of Chlorella sp. decreased first and then increased, appeared a minimum at 20℃.国家自然科学基金资助项目 (39870 5 6 5 );; 福建省自然科学基金资助项目 (C970 0 6

Gas Chromatographic Analysis of Fatty acid in Microalgae

以正十九酸（Ｃ１９：０）作内标，藻体经超声萃取、浓缩吹干，进行抽提酯化后采用毛细管气相色谱法分析测定。该方法重现性好，相对偏差为０．５３％～５．４９％，回收率较高，为９５．１％～１０２．５％，检测限为０．００７２ μ ｇ。In this study, a convenient and rapid method based on capillary gas chromatography is established for the analysis of fatty acid in marine microalgae. By this method, the fatty acids in algal cells are extracted by the ultrasonic method, then concentrated and desiccated in nitrogen gas. After esterification, the fatty acids are detected by capillary gas chromatography .The result shows the high recovery ratio (95.1%~l02.5%), the low relative deviation (0.53%~5.49%) and the low detecting threshold (0.0072 μg) of this method.国家自然科学基金（No．39870565）;; 福建省自然科学基金（No．C97006）共同资

Effect of Ultrasonic Radiation on the Fatty Acid Composition in Phaeodactylum tricornutum

研究了超声波对三角褐指藻脂肪酸组成的影响．在三角褐指藻整个生长期中每隔１２ ｈ 对其培养液进行超声辐射，结果表明，在较短超声作用时间下不饱和脂肪酸占总脂肪酸的百分比有明显的增加，尤其是Ｃ１８∶３ 百分含量得到大幅度的提高．Effect of the ultrasonic radiation on the contents and the composition of fatty acids in Phaeodactylum tricornutum is investigated. During the whole growth phase of Phaeodactylum tricornutum, culture medium was ultrasonically radiated every 12 hours. The result showed that the percent of the polyunsaturated fatty acids (especially C18∶3) increased obviously when culture medium was radiated at short time under present condition.国家自然科学基金!（39870565）;;福建省自然科学基金!（C97006

ZnF2包覆对锂离子电池正极材料LiNi0.5Mn1.5O4性能的影响

采用溶胶-凝胶法制备了LiNi0.5Mn1.5O4正极材料，并利用Zn F2对其表面进行包覆改性。XRD、SEM和TEM测试表明，包覆处理不影响材料的晶体结构，2%(质量分数，以LiNi0.5Mn1.5O4质量计，下同)的Zn F2在LiNi0.5Mn1.5O4表面形成了约7 nm厚均匀包覆层。对未包覆的LiNi0.5Mn1.5O4和1%、2%、3%的Zn F2包覆后的LiNi0.5Mn1.5O4的电化学性能进行了考察，发现Zn F2包覆能够减弱电解液与LiNi0.5Mn1.5O4正极材料之间的相互作用，稳定电极表面，提高材料的电化学性能。其中，2%Zn F2包覆样品表现出最佳的循环性能和倍率性能，0.2C电流倍率下循环200圈后，其放电比容量维持在109.0 m A·h/g，保持率为79.7%；5 C电流倍率下循环500圈后，放电比容量维持在94.2 m A·h/g，保持率为85.6%

Source of Particulate Organic Matter in the Daya Bay

本文采用脂肪酸作为生物标志物指示POM的来源.1995年5月和11月进行了两个航次的采样,样品中各脂肪酸组分的测定采用毛细管气相色谱法.结果表明,来源于陆生高等植物的长碳链饱和一元酸∑24—36占总脂肪酸(TfA)的比例较低,反映了陆源高等植物对大亚湾POM贡献很小;而主要来源于浮游生物的C14、C16、C18饱和一元酸及多不饱和脂肪酸含量占总脂肪酸含量的百分比较高,表明浮游生物对大亚湾POM有较大贡献.Suspended particles containing fatty acids were collected in May 1995 and November 1995 in the Daya Bay, and the composition of the fatty acid in the particles Was measured by gas chromatography.The results indicate that terrestrially-derived fatty acid is less important, and the ranges of ∑24～36/TFA (%) are 1.84%～7.22% (May 1995) and 1.09%～9.09% (November 1995) respectively.Polyunsaturated fatty acid and C14～C18 saturated fatty acid are predominant, suggesting that plankton is the main source of POM in the Daya Bay.中国科学院大亚湾海洋生物开放实验站资助(P9401

Gas Chromatographic Analysis of Fatty Acid in Microalgae

本文以正十九碳酸（C19：0）作内标，用HCI-CH3OH对海洋微藻（三角褐指藻）进行抽提酯化后做毛细管气相色谱分析。方法的重现性各脂肪酸的相对偏差为0.3%~11.6%，回收率为85.7%~103.3%，仪器稳定性的相对偏差为0.2%~3.1%。A capillary column gas chromatographic technique For the determination of microalgae ( phaeodactylum tricornutum )Fatty acids has been developed.The Fatty acid extraction and esteriFication is Finished in one step.Eleven kinds of Fatty acid methyl esters have been identiFied.The CV is less than 7% except C 22:5ω3 and the recovery rate 85.7～103.3%.Thus a rapid,convenient,reliable and microalytical method is established For the study on developing and making use of microalgae