中全新世（5400aBP）亚洲季风气候季节性与年际变率的南海珊瑚氧同位素记录

对现代珊瑚的氧同位素组成的季节与年际变化研究业已表明,海南岛东岸现代珊瑚氧同位素组成在冬季主要受表层海温控制,而在夏季则主要受夏季风降水决定的表层海水盐度影响.基于这一联系,本研究在高精度铀系测年基础上对中全新世滨珊瑚40a的同位素分析结果表明,5400a前的全新世中期滨珊瑚的δ18O值相对于现代升高了0.613‰(相当于11%),指示着海水δ18O值和盐度相对于现代的升高程度,可能主要与南海和太平洋水体交换强度增加所导致的盐度增大有关;结果同时显示,δ18O值的季节性幅度相对于现代增加了0.535‰(相当于33%),可能主要由冬季海水δ18O值升高引起,这一变化也与中全新世日照相对于现代的季节幅度增加相一致,分析认为日照增加引起的蒸发量增加和太平洋海水交换加强可能是根本原因.重建的冬夏季风代用指标的结果显示,中全新世冬夏季风的年际变率相对于现代都有所增加;谱分析结果揭示出冬季风年代尺度波动和夏季风约3a周期的存在,这些周期仍位于ENSO对季节变化的周期之内.     

Benthic foraminiferal fauna turnover at 2.1 Ma in the northern South China Sea

Quantitative analysis of benthic foraminifera from ODP Site 1146 in the northern South China Sea (SCS) shows that abundance of Bulimina alazanensis, sometimes up to about 90%, decreased gradually since 3.2 Ma, especially at 2.1 Ma. Abundance of other benthic foraminiferal species, Globobulimina sub-globosa and Cibicidoides wuellerstorfi, increased after 2.1 Ma. Comparison with changes in oxygen and carbon isotopes of planktonic and benthic foraminifera shows that high abundance values of B. alazanensis corresponded with lower values of oxygen isotope, but for carbon isotope, high values of the species were consistent with heavier carbon isotope of benthic foraminifera and lighter carbon isotope of planktonic foraminifera, respectively, and vice versa. Considering factors such as uplift of Bashi Strait, expansion of the North Hemisphere Glaciation, strengthening of East Asian winter mon-soon and variations in oxygen and carbon isotope of foraminifera, changes of B. alazanensis in ODP Site 1146 suggest that the source of deep water masses of the northern South China Sea changed from the warm Pacific deep water with high oxygen content to Pacific Intermediate water with low oxygen content at 2.1 Ma. In addition, the strengthened East Asian winter monsoon resulted in increased pri-mary productivity, high nutrient and suboxic bottom water. Variations in species of B. alazanensis seemed to be unable to tolerate environmental stress induced by deep water masses and productivity changes.     

Clay minerals in surface sediments of the Pearl River drainage basin and their contribution to the South China Sea

Clay minerals have played a significant role in the study of the East Asian monsoon evolution in the South China Sea by being able to track oceanic current variations and to reveal contemporaneous paleoclimaUc changes prevailing in continental source areas. As one of the most important rivers inputting terrigenous matters to the northern South China Sea, the Pearl River was not previously paid attention to from the viewpoint of clay mineralogy. This paper presents a detailed study on clay minerals in surface sediments collected from the Pearl River drainage basin （including all three main channels, various branches, and the Lingdingyang in the estuary） by using the X-ray diffraction （XRD） method. The results indicate that the clay mineral assemblage consists dominantly of kaolinite （35%-65%）, lesser abundance of chlorite （20%-35%） and illite （12%-42%）, and very scare smectite occurrences （generally 〈5%）. Their respective distribution does not present any obvious difference throughout the Pearl River drainage basin. However, downstream the Pearl River to the northern South China Sea, the clay mineral assemblage varies significantly： kaolinite decreases gradually, smecUte and illite increase gradually. Additionally, illite chemistry index steps down and illite crystallinity steps up. These variations indicate the contribution of major kaolinite, lesser illite and chlorite, and very scarce smecUte to the northern South China Sea from the Pearl River drainage basin. The maximum contribution of clay minerals from the Pearl River is 72% to the northern margin and only 15% to the northern slope of the South China Sea. In both glacials and interglacials, kaolinite indicates that the ability of mechanical erosion occurred in the Pearl River drainage basin.     

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.     

污水的人工湿地净化概述

介绍了人工湿地的类型、特点及对污染物的净化机理，并探讨了这种工艺的研究方向与应用前景。     

Authigenic sulfide minerals and their sulfur isotopes in sediments of the northern continental slope of the South China Sea and their implications for methane flux and gas hydrate formation

This is a report of the study of the authigenic sulfide minerals and their sulfur isotopes in a sediment core (NH-1) collected on the northern continental slope of the South China Sea, where other geo-physical and geochemical evidence seems to suggest gas hydrate formation in the sediments. The study has led to the findings: (1) the pyrite content in sediments was relatively high and its grain size relatively large compared with that in normal pelagic or hemipelagic sediments; (2) the shallowest depth of the acid volatile sulfide (AVS) content maximum was at 437.5 cm (>2 μmol/g), which was deeper than that of the authigenic pyrite content maximum (at 141.5-380.5 cm); (3) δ 34S of authigenic pyrite was positive (maximum: 15‰) at depth interval of 250-380 cm; (4) the positive δ 34S coincided with pyrite enrichment. Compared with the results obtained from the Black Sea sediments by Jorgen-sen and coworkers, these observations indicated that at the NH-1 site, the depth of the sulfate-methane interface (SMI) would be or once was at about 437.5-547.5 cm and the relatively shallow SMI depth suggested high upward methane fluxes. This was in good agreement with the results obtained from pore water sulfate gradients and core head-space methane concentrations in sediment cores collected in the area. All available evidence suggested that methane gas hydrate formation may exist or may have existed in the underlying sediments.     

湿地降温增湿效应的数值模拟研究

采用数值模拟方法研究湿地对周边区域空气的降温增湿效应，建立了空气、水气的流动与扩散混合模型，描述给定空间的传热传质过程．控制方程包括连续方程、动量方程、能量方程和水气守恒方程．对每一相各自的流动，采用κ-ε双方程模型；对于两相的湍流流动，采用混合湍流模型．用FLUENT软件进行数值计算，得出给定区域的空气温度、相对湿度的空间分布．对实测案例进行了数值模拟，计算值与测定值符合良好，表明所建立的模型和计算方法可以很好地描述湿地对周边区域空气温度和湿度的影响．由等温线可以看到，低温空气的扩散在近湿地处，影响最大的区域距地面一定高度．冷空气从湿地边沿向远处及上下扩散，在温度最低区略有上升，到一定远处又下降至地面．对于相对湿度，在靠近湿地区域水气对地面附近的影响比气温影响明显，而远处水气对地面附近的影响不及气温影响大．     

巢湖十五里河河口湿地植物群落多样性分析

依据巢湖十五里河河口植物群落野外调查资料,运用PCORD软件中Euclidean距离和Ward’s meth-od聚类方法研究了河口湿地植物群落的特征及多样性变化;用收获法研究了植物群落的生物量变化。研究显示:十五里河河口湿地植物群落由21个种组成,它们隶属于18属,11科,其中假稻(Leersia japonica)、北水苦荬(Veronica anagallis aquatica)、长芒野稗(Echinochloa caudata)、芮草(Beckmannia syzigachne)、黄花蒿(Artemisia annua)和水花生(Alternanthera philoxeroides)为优势种;河口湿地植物群落可分为8个组合,其中分布在湖堤附近的黄花蒿 北水苦荬(Artemisia annua Veronica anagallis aquatica)组合多样性指数和均匀度指数最高,分别为2.06和0.94;组合中物种多样性指数与物种丰富度和均匀度指数线性相关性不明显,其相关系数分别为0.609和0.549;组合的分布、生物量和多样性均与水位变化有密切关系。     

应用耐冷菌株改善寒冷地区冬季人工湿地系统生物脱氮效果

通过探索性实验,确定了三种耐冷菌培养基,分别用于培养耐冷细菌、耐冷放线菌和耐冷霉菌.培养出的耐冷菌株在6℃条件下被分离纯化,然后通过一系列实验分别鉴定它们的生理特性并检验它们的脱氮能力,并测定pH值、温度对脱氮效果的影响规律.实验结果显示pH值为7～8时,各菌株生长得最好;生物荧光层析光谱实验发现三种菌株都在15℃左右活性最大,0℃以下仍有一定的活性,高于35℃时,基本失去正常的代谢能力.当实验菌液投加量为5.0%,实验温度为6℃,三种耐冷菌对氨氮的去除率分别为57.7%、59.0%及58.7%,相同条件下,投加混合菌种可使氨氮的去除率提高到67.2%.     

澳大利亚高压对南海夏季风爆发前期的影响

利用NCEP/NCAR的在分析资料,分析了1948～2004年期间澳大利亚（以下简称澳高）的年变化和日变化及其对南海夏季风的影响。结果显示在澳高强弱年这种影响有着不同的结果：在年际变化中,澳高与南海夏季风的相关性在澳高弱年明显大于强澳高年;而日变化中,澳高与南海夏季风的相关性在澳高弱年为正,澳高强年则为负。进一步研究表明,造成这些现象的原因大致可以归为：强弱澳高年,越赤道气流的通道变换;西太平洋副热带高压（以下简称副高）的位置偏向;马斯可林高压（以下简称马高）的作用的叠加效应.这些作用对于南海夏季风的重要组成部分：越赤道气流产生了重要影响,从而影响了南海夏季风的强度。