湖北梁子湖近代沉积记录对人类活动的响应

为了研究人类活动背景下的湖泊生态响应过程和机制, 分析人类活动对湖泊富营养化的贡献, 在210Pb计年和历史事件记载基础上, 通过梁子湖沉积物水生生物遗存和色素分析重建了梁子湖地区过去100多年来湖泊生态系统演化过程.沉积物色素和水生生物遗存组合带的变化表明梁子湖营养演化具有5个阶段: 过去100多年梁子湖地区经历了生态环境良好的贫营养化期(1885-1902A.D.)、轻度富营养化期(1902-1964A.D.)、中度富营养化期(1964-1988A.D.)、富营养化期(1988-1998A.D.)、中度富营养化期(1998-2003A.D.).水生生物遗存随着湖泊富营养化的发生而呈现一定的分布特征, 对富营养化敏感的奥古茨藻、荇菜、角果藻、纹沼螺、表壳虫等逐步减少.通过湖泊演化阶段与区域人类活动重大阶段的联合对比研究发现随着人类活动的增强及对湖泊生态的持续干扰, 湖泊生态演化呈现明显的阶段性, 湖泊富营养化的发生与流域强烈的人类活动如围垦与农业活动带来的营养物质输入有着直接联系, 湖泊生态环境演化对重大人类活动事件具有响应性.本研究对于认识湖泊生态环境演化与人类活动的关系、整治湖泊环境具有重要的指导意义.      

Recovery of astaxanthin from discharged wastewater during the production of chitin

In this paper, studies were carried out to extract astaxanthin from discharged wastewater during the production of chitin and to reveal the scavenging effect of the obtained pigment on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical. Different ratios of dichloromethane/methanol (V/V) were used to extract astaxanthin. When the ratio of dichloromethane/methanol was 2:8 and the ratio between the mixed organic solvent (dichloromethane/methanol, 2:8, V/V) and wastewater was 1:1, the highest yield of pigment was obtained (8.4 mg/ 50 mL). The concentration of free astaxanthin in the obtained pigment analyzed by HPLC was 30.02%. The obtained pigment possessed strong scavenging ability on DPPH radical and IC50 was 0.84mg/ml.     

Fossil pigments as indicators for palaeoclimatic interpretations —A case study of Qinghai Lake

An 82 cm core was collected from Qinghai Lake in the Qinghai-Xizang Plateau, China and sectioned in intervals of 1 cm for analysis of pigments (i. e. chlorophyll derivatives, carotenoids, myxoxanthophyll, oscillaxanthin) and²¹⁰Pb.²¹⁰Pb dating was used to establish the chronological sequence. The concentrations of myxoxanthophyll and oscillaxanthin from the cyanophytes increase with temperature. There are four peak values at 0–14 cm (present−1891a), 25 cm (1786a), 45 cm (1581a), 60 cm (1416a) representing four warm and low water level periods during the past 700 years. This was confirmed by the high concentration of carbonate and ∂¹³C in these stages. In these 700 years, there were also 4 periods of cold wet climate and high water level as indicated by the tree ring index and high value of native chlorophyll and high, variable CD/TC ratios. The project was supported by the Loess and Quaternary Research Lab, Academia Sinica.     

The extraction of pigments from fresh <Emphasis Type="Italic">Laminaria japonica</Emphasis>

The pigments in Laminariajaponica was extracted with six organic solvents and analyzed in spectroscopy analysis. The extractions conditions were screened by an orthogonal test and the quantity of extracted pigments was determined spectroscopically. The results show that： （1） among the six organic solvents, acetone was the most effective one for the extraction; （2） the optimum extraction conditions were as follows： the ratio of S/M （solvent volume/ material weight） was 30 ml/g; fresh seaweed was extracted 2 times in 2 h; （3） the average total content of pigments was 1.85 mg/g （calculated with dry L. japonica）.     

南极普里兹湾临近海域夏季纽鳃樽对浮游植物的摄食研究

于 1 998年 1 2月至 1 999年 1月南极夏季 ,对南大洋普里兹湾临近海域主要被囊类纽鳃樽的数量密度分布进行了现场调查 ,同时于 - 3站对纽鳃樽对浮游植物的摄食率利用肠道色索法和颗粒递减法进行了现场研究。调查结果表明 ,纽鳃樽主要分布于调查海区的浮冰区北部边缘及其以北的开阔水域。在密集区其数量密度高达 2 795ind..1 0 0 0 m- 3,浮冰区几乎没有发现。 - 3站现场摄食实验结果显示 ,纽鳃樽个体肠道色素含量变化范围为 0 .1 4～ 1 .2 7μg.ind.- 1,平均为0 .98μg.ind.- 1。肠道色素法测得的纽鳃樽对浮游植物的摄食率为 7.9μg.ind.- 1d- 1,滤水率为2 81 ind.- 1d- 1。颗粒递减法测得纽鳃樽滤水率为 1 5.3± 4.61 ind.- 1d- 1,比肠道色素法所得结果偏低。虽然由此推算纽鳃樽群体的日摄食量只占浮游植物现存量的 0 .8% ,但是对于初级生产力却有一定的摄食压力 ( 72 .2 % )。