时间域混合像元分析在海冰密集度变化研究中的应用

传统意义混合像元分析方法是对有不同光谱特征的地物进行分解(spectral mixture analysis,SMA),得到各个组分在该像元内所占的百分数。而将光谱域的混合像元分析延伸至时间域内(temporalmixture analysis,TMA),提取的表征时间特性的端元用于像元分解所得残差小于8.5%,说明TMA提取南极地区海冰密集度时间变化特性具有可行性。将获取的多年平均端元用于2005年和2010年海冰密集度数据,得到残差分别为(1.4±2.42)%和(1.7±2.87)%,高于多年平均残差精度(1±1.53)%,在一定程度上反映某年海冰密集度数据相对多年平均值的变化。因此,TMA为全球变暖背景下的海冰密集度的时空特性研究提供了新思路。     

海冰冰裂缝自动化检测装置及其系统在南极海冰监测中的应用研究

南极海冰冰裂缝宽度的变化严重影响人类在南极活动中冰上物资的运输,利用研制成功的电容感应式冰原传感器,设计并研究了南极海冰冰裂缝的自动化检测装置及其系统,并对该套系统在南极海冰的试验应用进行了分析,结果证明,该冰裂缝检测装置及其系统能较好的实现海冰裂缝的无人自动化监测.     

从北极高压、南极低压到南北极间的三维异宿轨道

本文利用球坐标系(λ,φ,r)中的球面地转风关系,说明当等压线形成最简单的纬向分布时,此时南极是低压,北极是高压. 但是,当在地转风关系中加入摩擦力后,则南北极由闭合涡旋变成螺旋涡旋,且两极之间形成一条球面上的三维异宿轨道. 关键词： 北极高压 南极低压 摩擦力 异宿轨道     

Effects of ultrasound-assisted basic electrolyzed water (BEW) extraction on structural and functional properties of Antarctic krill (Euphausia superba) proteins

A novel protein extraction method of ultrasound-assisted basic electrolyzed water (BEW) was proposed, and its effects on the structural and functional properties of Antarctic krill proteins were investigated. Results showed that BEW reduced 30.9% (w/w) NaOH consumption for the extraction of krill proteins, and its negative redox potential (−800 ~ −900 mV) protected the active groups (carbonyl, free sulfhydryl, etc.) of the proteins from oxidation compared to deionized water (DW). Moreover, the ultrasound-assisted BEW increased the extraction yield (9.4%), improved the solubility (8.5%), reduced the particle size (57 nm), favored the transition of α-helix and β-turn to β-sheet, promoted the surface hydrophobicity and disulfide bonds formation of krill proteins when compared to BEW without ultrasound. These changes contributed to the enhanced foam capacity, foam stability and emulsifying capacity of the krill proteins. Notably, all the physicochemical, structural and functional properties of the krill proteins were comparable to those extracted by the traditional ultrasound-assisted DW. This study suggests that the ultrasound-assisted BEW can be a potential candidate to extract proteins, especially offering an alternative way to produce marine proteins with high nutritional quality.     

Determination of water-soluble and insoluble (dilute-HCl-extractable) fractions of Cd,Pb and Cu in Antarctic aerosol by square wave anodic stripping voltammetry: distribution and summer seasonal evolution at Terra Nova Bay (Victoria Land)

Eight PM10 aerosol samples were collected in the vicinity of the “Mario Zucchelli” Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000–2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84–9.2 μg g⁻¹ (average 4.7 μg g⁻¹), Pb 13.2–81 μg g⁻¹ (average 33 μg g⁻¹), Cu 126–628 μg g⁻¹ (average 378 μg g⁻¹). In terms of atmospheric concentration, the values were: Cd 0.55–6.3 pg m⁻³ (average 3.4 pg m⁻³), Pb 8.7–48 pg m⁻³ (average 24 pg m⁻³), Cu 75–365 pg m⁻³ (average 266 pg m⁻³). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90–100%, and lower for Cu, 70–90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (∼10% and ∼5%, respectively), while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions (possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source. Figure Aerosol sampling in Antarctica     

Survey on minor and trace elements in Antarctic and Arctic biota as indicators of local and global-scale pollution

Trace and minor elements in biota in the extreme regions of the planet (Antarctic, Arctic and related areas) play a pivotal role to assess global pollution and climate changes. The relevant scientific literature was scanned over the period 1978–2008 and the most recent trends in polar research in this field were outlined. In this context, two aspects were found to be of paramount importance, i.e., the role of sentinel organisms in monitoring ongoing processes of environmental pollution caused by chemical elements and the implementation of quality systems to attach credibility to experimental information.     

Hydrogen and Carbon Monoxide at Terra Nova Bay (ANTARCTICA)

Abstract

Studies on atrazine ozonation performed in methanol containing solutions showed a strong influence of the methanol content which might favour direct O₃ reactions as compared to processes induced by OH radicals. The importance of the slackening effect on the degradation rate of atrazine (which demonstrates a scavenger activity) was evaluated in various solvent compositions and pseudo-kinetic constants k' were found to be in the 10^?3-10^?2 s^?1 range. The appearence rate of deethylatrazine as major oxidation product was thus also modified (k' values between 10^?4 and 10^?3 s^?1). Several by-products were detected which are either related to deethylatrazine (intermediates or oxidation products) or belong to competitive pathways. Among them, a number of formamides (a new class of atrazine ozonation products) were identified using MS and MS-MS techniques. These compounds are produced by oxidation of the N-ethylamino group likely through a non radicalar process. Deschloro-triazines were also characterized as structures whose formation specifically depends on the presence of methanol.     

Determination of biotin in Antarctic krill (Euphausia superba) by high‐performance TLC with different post‐chromatographic derivatizations

A new efficient method was developed to detect biotin in Antarctic krill by Vis‐absorbance detection. DMF was used after chloroform pretreatment to extract biotin and two chromogenic methods were developed. The development system consisted of dichloromethane/dimethylcarbinol/methanol/glacial acetic acid (3:3:2:0.015, v/v/v/v). Samples were separated on precoated silica gel GF254 high‐performance TLC plates. Densitometric analysis of biotin was carried out in the absorbance mode at 400 and 530 nm. The biotin content was determined to be 1.0948 ± 0.0097 and 1.1212 ± 0.0155 mg/g in Antarctic krill with the two chromogenic methods, which had no significant difference.     

Book Reviews

Abstract

HANDBOOK FOR ESTIMATING PHYSICOCHEMICAL PROPERTIES OF ORGANIC COMPOUNDS, by M. Reinhard and A. Drefal, 228 pages, J. Wiley, New York (1999). ISBN 0—471—172634. UK £ 210.00

THE CHEMISTRY OF POLLUTION, by G. Fellenberg, 192 pp. J. Wiley & Sons, Chichester, U.K. (1999). ISBN 0—471—980889. UK£ 24,95.

NATURAL ATTENUATION OF FUELS AND CHLORINATED SOLVENTS IN THE SUBSURFACE, by T.H. Wiedemeier, H.S. Rifai, C.J. Newell and J.T. Wilson, 617 pages, J. Wiley, New York (1999). ISBN 0—471—19749—1. UK £ 58.50

UNDERSTANDING OUR ENVIRONMENT, 3^rd, edition, edited by R.M. Harrison, 445 pages, The Royal Society of Chemistry, Cambridge (UK) (1999). ISBN 0—85404—584—8. UK£ 19.95

ENDOCRINE DISRUPTING CHEMICALS, Vol. 12 of Issues in Environmental Science and Technology, edited by R.E. Hester and R.H. Harrison, 152 pages, Royal Society of Chemistry, Cambridge (U.K.) (1999). ISBN 0—85404—255—5. UK£ 25,00

METHOD PERFORMANCE STUDIES FOR SPECIATION ANALYSIS. by P. Quevauviller, 271 pages, The Royal Society of Chemistry, Cambridge (U.K.) (1998). ISBN 0—85404—467—1. UK£ 59.50

GLOBAL AQUATIC AND ATMOSPHERIC ENVIRONMENT, by H.D. Kumar and D.P. Häder, 393 pages, Springer, Berlin (1999). ISBN 3—540—65369—4. USD 229.00

BIOACCUMULATION. New Aspects and Developments, edited by B. Beek, 284 pages, Springer, Heidelberg, 2000. ISBN 3—540—62575. USD 143.00

INTERLABORATORY STUDIES AND CERTIFIED REFERENCE MATERIALS FOR ENVIRONMENTAL ANALYSIS. The BCR approach, by Ph. Quevauviller and E.A. Maier, 558 pages, Elsevier Science, Amsterdam NL, (1999). ISBN 0—444—82389—1. USD 251.50 (Euro 224.62).     

COMPARATIVE RESEARCH ON ENVIRONMENTAL EVOLUTION BETWEEN THE RECION OF ANTARCTIC GREAT WALL STATION AND CHINA

Through comparative analysis between the environmental changes in the region of KingGeorge Island in Antarctic and the characteristics of environmental evolution in the differentregions of China, the paper reveals the important similarity of the environmental evolutionbetween the two regions. The fine correspondence relations between the environmentalchanges of King George Island region in Antarctic, the glacial activities on the mountainousterrain in the western part of China, and the oscillation of the northern boundary of sub-tropical zone in the eastern part of China pointed out in this study serve as evidence to sup-port the interaction between the Northern and Southern Hemispheres. The uniformity of theclimatic changes of the King George Island region in Antarctic with the changes of sea levelof China and the world also supports the similarity of the trend of global changes in tem-perature since the Holocene. One must pay attention to the macroscopic and integrated studyof the whole earth in order