冲绳海槽中部玄武岩的岩石学和地球化学研究

1992年冲绳海槽地质调查时,在134站(126°56′7″E,27°30′0″N)共采集到3件玄武岩样品,其中1件取自134站表层样,另外2件取自134站柱状样中的118-143cm处和193- 218cm处(刀口位置)。通过对上述3件玄武岩样品的岩相学、岩石化学组成、稀土元素和微量元素和锶同位素比值分析研究,认为本区玄武岩具多期次喷发特征,早期喷发形成的玄武岩中单斜辉石质量分数较低,晚期喷发形成的玄武岩中单斜辉石质量分数相对较高,表明了单斜辉石为晚期结晶堆积产物。本区玄武岩稀土配分模式与岛弧拉斑玄武岩基本一致,其⁸⁷Sr与⁸⁶Sr质量分数比值m(⁸⁷Sr)/m(⁸⁶Sr)为0.7046,亦与岛弧拉斑玄武岩相当。最后利用Rb-Sr丰度特征确定本区的地壳厚度为19-24 km。     

Observations of some oxygen-containing and sulfur-containing organic molecules in cold dark clouds

Observations of nine oxygen- and sulfur-containing organic molecules have been made toward the cold dark clouds TMC-1 and L134N. We have confirmed the presence of para-ketene (H2C2O) in TMC-1, have for the first time observed ortho-ketene, and find a total ketene column density approximately 1 x 10(13) cm-2. Thioformaldehyde (H2CS) is easily detectable in both TMC-1 and L134N, with a column density about 5 times larger in the former source (approximately 3 x 10(13) cm-2). The fractional abundance of ketene is comparable to the predictions of ion-molecule chemistry, while that of thioformaldehyde in TMC-1 is one to two orders of magnitude greater than that expected from such models at steady state. Interstellar sulfur chemistry thus continues to be poorly understood. We set upper limits for the column densities of formic acid (HCOOH), vinyl alcohol (CH2CHOH), methyl formate (HCO2CH3), formamide (NH2CHO), methyl mercaptan (CH3SH), isothiocyanic acid (HNCS), and thioketene (H2C2S) in both sources.     

基于卫星遥感的城市绿地景观格局变化研究进展

城市绿地景观是城市景观自然要素和社会经济可持续发展的生态基础,在城市景观结构、功能及其变化中起重要作用。利用卫星遥感技术开展城市绿地格局研究已成为热点。本文通过梳理相关研究成果,阐述了城市绿地景观遥感分类方法、景观格局指数的选择及城市绿地景观格局动态变化驱动力分析的具体内容,分析出基于遥感技术的城市绿地景观格局研究在数据源和景观格局指数选择时所存在的不足,并且从遥感数据源、分类方法、景观指数筛选和多学科、多角度交叉综合的研究方法等方面对城市绿地景观格局分析提出展望。     

海洋动物标准物质的研制及其技术流程

以缢蛏为例,详细介绍了海洋动物标准物质的研制及其技术流程,对研制过程中候选物的确定,以及标准物质所必须具备的特性量值等进行了全面叙述.海洋动物标准物质制备的技术流程主要包括:均匀性、稳定性和准确性的检验,定值分析方法、数据的统计分析以及定值数据结果的表达.有证标准物质的包装运输、认定证书和标签等方面的操作也都应按照规定...     

Measurement of Labile Cu, Pb and Their Complexation Capacity in Yueqing Bay in Zhejiang Province, China

1　INTRODUCTIONRecently ,thepollutionoftracemetalinseawaterhasbecomeincreasinglyevident.Researchershavefo cusedattentiontotracemetalpresentinvariousexistenceforms ,especiallyorganiccomplexingphases.Theexistencestatesandtransportmechanismofbaytracemetalswerethesubjectofstudybysomere searchers(Gu ,1 991 ;Florence ,1 998;Guo ,1 998;Wells,1 991 ,1 998a ,b ;Wellsetal.,1 998) .Whetherinfreshwaterorseawater,colloidsareclearlydominantfactorsaffectingtheexistencestatesandtransportmechanismoftrac…     

Cytochrome P450 isozyme protein verified in the skin of southern hemisphere humpback whales (Megaptera novaeangliae): implications for biochemical biomarker assessment

Large mysticete whales represent a unique challenge for chemical risk assessment. Few epidemiological investigations are possible due to the low incidence of adult stranding events. Similarly their often extreme life-history adaptations of prolonged migration and fasting challenge exposure assumptions. Molecular biomarkers offer the potential to complement information yielded through tissue chemical analysis, as well as providing evidence of a molecular response to chemical exposure. In this study we confirm the presence of cytochrome P450 reductase (CPR) and cytochrome P450 isoenzyme 1A1 (CYP1A1) in epidermal tissue of southern hemisphere humpback whales (Megaptera novaeangliae). The detection of CYP1A1 in the integument of the humpback whale affords the opportunity for further quantitative non-destructive investigations of enzyme activity as a function of chemical stress.     

Implications of dredging induced changes in sediment particle size composition for the structure and function of marine benthic macrofaunal communities

A meta-analysis approach was used to assess the effect of dredging induced changes in sediment composition, under different conditions of natural physical disturbance, for the structure and function of marine benthic macrofaunal communities. Results showed the sensitivity of macrofaunal communities increased as both the proportion of gravel increased and the level of natural physical disturbance decreased. These findings may be explained by the close association of certain taxa with the gravel fraction, and the influence of natural physical disturbance which, as it increases, tends to restrict the colonisation by these species. We conclude that maintaining the gravel content of surface sediments after dredging and, where practicable, locating extraction sites in areas of higher natural disturbance will minimise the potential for long-term negative impacts on the macrofauna.     

浅谈如何处理《海洋地质学》教学中“厚”与“薄”的关系

在海洋地质学教学实践的基础上,针对该课程学时少而教学容量大的特点,就教材讲授中"厚"与"薄"的关系,提出了协调两者关系的几点建议。     

长江口溶解氧赤潮预报简易模式

在海洋浮游生物中,有很多单细胞微小生物,由于异常地急剧繁殖,并高度密集在一起,从而引起海水变色的现象,称谓“赤潮”.目前,普遍认为赤潮的发生与海水中磷、氮等营养盐、铁、锰等微量元素以及某些有机化合物的大量增加有关[l];另外,还与水体的停滞和气象条件密切联系[2,3].赤潮的发生意味着生态平衡的破坏.