Trace analysis of quaternary aminoalcohols as degradation products from softeners in wastewater     

H. Engelhardt  W. Gtzinger  M. Krmer  R. Wintringer 《洁净——土壤、空气、水》1995,23(4):173-179

The sensitive and selective determination of polyalcohols without chromophores or fluorophores in the lower ppb-level is still an analytical task of high interest, especially in the field of environmental investigations. This paper describes a cation-exchange HPLC procedure for the separation and fluorescence detection of two quaternary ammonium compounds with polyalcoholic groups (degradation products of fabric softener) after derivatization with 9-fluorenylmethyl chloroformate (FMOC). Detailed experiments were carried out to determine optimum reaction conditions (pH, reaction time, temperature), linear range, detection limits, and kinetics of the reaction. The HPLC separation on a cation-exchange column includes a gradient program which provides complete separation from neutral compounds also reacting with FMOC and its hydrolysis products formed during the reaction in alkaline medium. High specificity for both investigated ammonium compounds with detection limits in the range of 1 ppb could be achieved.  相似文献   

第四纪时期地壳块体相对运动的古地磁记录的初步研究─-以陇西和鄂尔多斯块体相对运动为例   总被引：2，自引：0，他引：2  

刘爱国  卢演俦  丁国瑜 《地震地质》1995,17(4):397

为了探讨用古地磁方法确定第四纪时期地壳块体相对运动状况，选择了分别处于陇西块体和鄂尔多斯块体内的兰州九州台和陕西洛川两个黄土剖面作为实验对象。在这两个黄土剖面的４个相同年代的层位采集定向大样，作黄土沉积剩余磁化矢量测量，并用虚磁极法拟合，初步结果表明，约１１０万ａ来陇西块体相对于鄂尔多斯块体作顺时针旋转，其转动量达９．０±４．７°  相似文献   

地学家袁复礼先生与第四纪地质学——纪念袁复礼先生逝世20周年     

袁扬  胡世玲 《第四纪研究》2007,27(5):896-899

袁复礼(1893.12.31～1987.5.22),字希渊,河北徐水县人.著名地质学家、教授、教育家.1913年考入清华学校高等科,1915年获庚子赔款奖学金赴美深造.1920年获硕士学位,1921年回国进入地质调查所工作,从此献身地质事业.他是中国地质学会的创立会员,曾任清华大学教授、地学系主任,北京大学、西南联合大学、北京地质学院、中国地质大学教授.从教60余年,培养了几代地质人才,对中国的地质教育事业做出了重要贡献.他1924年开设了《地文学》课程,1953年开始编写了我国第一本《中国第四纪地质学》教材,他的文章涉及到第四纪地质、地貌、新构造运动等各个方面,是我国当代地貌学和第四纪地质学的奠基人.  相似文献   

Cosmogenic nuclide measurements in southernmost South America and implications for landscape change     

M.R. Kaplan  A. Coronato  N.R.J. Hulton  J.O. Rabassa  P.W. Kubik  S.P.H.T. Freeman 《Geomorphology》2007,87(4):284-301

We measured in situ ¹⁰Be, ²⁶Al and³⁶Cl on glacial deposits as old as 1.1 Myr in the southernmost part of Patagonia and on northern Tierra del Fuego to understand boulder and moraine and, by inference, landscape changes. Nuclide concentrations indicate that surface boulders have been exposed for far less time than the ages of moraines they sit upon. The moraine ages are themselves constrained by previously obtained ⁴⁰Ar/³⁹Ar ages on interbedded lava flows or U-series and amino acid measurements on related (non-glacial) marine deposits. We suggest that a combination of boulder erosion and their exhumation from the moraine matrix could cause the erratics to have a large age variance and often short exposure histories, despite the fact that some moraine landforms are demonstrably 1 Myr old. We hypothesize that fast or episodic rates of landscape change occurred during glacial times or near the sea during interglacials. Comparison with boulder erosion rates and exhumation histories derived for the middle latitudes of semi-arid Patagonia imply different geomorphic processes operating in southernmost South America. We infer a faster rate of landscape degradation towards the higher latitudes where conditions have been colder and wetter.  相似文献   

南京汤山驼子洞洞穴堆积及其意义     

周春林  房迎三  陆从伦 《地层学杂志》2007,31(1):45-49

通过对南京汤山驼子洞洞穴堆积观察描述和样品分析测试,结合前人研究成果和汤山地区地质地貌演化的历史,讨论了驼子洞堆积的时代、堆积过程和方式,并对其蕴含的构造、地貌、气候和生物进化等古环境信息进行了合理的挖掘。初步研究表明驼子洞堆积可能是跨早更新世与中更新世早期的地层,其上部含哺乳动物化石的堆积可能反映了偏暖的气候环境。  相似文献   

Late Quaternary clay minerals off Middle Vietnam in the western South China Sea: Implications for source analysis and East Asian monsoon evolution     

Christophe COLIN 《中国科学D辑(英文版)》2007,50(11):1674-1684

High-resolution clay mineral records combined with oxygen isotopic stratigraphy over the past 450 ka during late Quaternary from Core MD05-2901 off Middle Vietnam in the western South China Sea are re-ported to reconstruct a history of East Asian monsoon evolution. Variations in Illite, chlorite, and kaolinite contents indicate a strong glacial-interglacial cyclicity, while changes in smectite content present a higher frequency cyclicity. The provenance analysis indicates a mixture of individual clay minerals from various sources surrounding the South China Sea. Smectite derived mainly from the Sunda shelf and its major source area of the Indonesian islands. Illite and chlorite originated mainly from the Mekong and Red rivers. Kaolinite was provided mainly by the Pearl River. Spectral analysis of the kaolin-ite/(illite chlorite) ratio displays a strong eccentricity period of 100 ka, implying the ice sheet-forced win-ter monsoon evolution; whereas higher frequency changes in the smectite content show an ice sheet-forced obliquity period of 41 ka, and precession periods of 23 and 19 ka and a semi-precession period of 13 ka as well, implying the tropical-forced summer monsoon evolution. The winter monsoon evolution is generally in coherence with the glacial-interglacial cyclicity, with intensified winter monsoon winds during glacials and weakened winter monsoon winds during interglacials; whereas the summer monsoon evolution provides an almost linear response to the summer insolation of low latitude in the Northern Hemisphere, with strengthened summer monsoon during higher insolation and weakened summer monsoon during lower insolation. The result suggests that the high-latitude ice sheet and low-latitude tropical factor could drive the late Quaternary evolution of East Asian winter and summer monsoons, respectively, implying their diplex and self-contained forcing mechanism.  相似文献   

南海北部陆坡ODP 1144站位第四纪硅藻及其古环境演变   总被引：9，自引：0，他引：9  

李家英 《地质论评》2002,48(5):542-551

中国南海北部陆坡ODP 1144站位硅藻植物群的研究，建立了西太平洋边缘海一个新的中更新世晚期以来的硅藻生物地层图式，根据硅藻化石中具有指示意义的硅藻种的分布和生态变化（暖水种和冷水种），划分了8个硅藻组合带，其硅藻组合带分别在不同的高低海面环境下形成的，根据ODP1144站位氧同位素（OIS）测定结果，8个硅藻组合带与OIS 1－8期相对应。1、3、5、7硅藻组合带相当于OIS1、3、5、7期，间冰期是以热带和亚热带硅藻占优势，其中冷期出现大量的沿岸硅藻为特征，反映高海平面温暖的气候条件；2、4、6、8硅藻组合带相当于OIS2、4、6、8期，冰期是以亚热带，热带和出现较多冷水硅藻为特征，反映低海平面较冷气候条件，硅藻丰度值的变化与冰期和间冰期有关，可以证实间冰期时期高的海平面和较低的生物生产力以及冰期时低的海平面和高的生物生产力，而生物生产力的变化又与沉积时期沿岸流或上升流的强弱及水团活动有密切关系，进而揭示该区古海洋环境的演化与季风强弱之间的内在关系。  相似文献   

塔克拉玛干沙漠腹地第四纪地层划分与环境变迁   总被引：6，自引：0，他引：6  

张鸿义  门国发 《新疆地质》2002,20(3):256-261

通过塔中地区KT1孔和KT2孔井下第四纪地质测试研究，首次揭示出：塔克拉玛干沙漠腹地在深度653.80m以上，沉积物可划分42层，基本属于第四系。第四系下限初步定在761.17m深处。第四纪以来的气候演化大体有过3次大的气候波动和13个较大气候波动旋回。沉积环境早更新世为河湖相泛滥平原；中更新世以洼地湖泊相沉积为主，同时明显加入了风沙环境堆积，沙漠开始形成；从中更新世晚期开始，经晚更新世到新世，沙漠大规模形成，并逐步发展成今日的大沙漠景观。  相似文献   

青藏高原新生代构造和第四纪研究的进展及问题讨论   总被引：2，自引：2，他引：2       下载免费PDF全文

袁道阳  张培震 《地震工程学报》2001,23(2):199-205

简述了近年来国内外在青藏高原晚新生代构造和第四纪地质研究方面所取得的新进展，针对在活动构造研究中所存在的问题，提出 今后研究工作的方向，认为应当加强青藏高原及其周缘地区晚新生代构造变形方式、幅度和速率的研究，同时在研究中应当将第四纪地质与活动构造研究相结合，特别要注重深部构造的研究。  相似文献   

洞庭湖区第四纪气候变化的初步探讨   总被引：14，自引：0，他引：14  

张人权  梁杏  张国梁  皮建高 《地质科技情报》2001,20(2):1-5

探讨了洞庭湖区第四纪以来的气候变化，初步得出以下规律：更新世气候变化剧烈，气候组合暖湿（温湿）与冷干；全新世气候转为温凉，主要气候组合为温湿与凉干；历史时期气候主要仍温湿与凉干交替，但15 世纪以来出现短暂的温干与凉温期；15世纪以来，气候波动频繁，有愈来愈不稳定的趋向，进入20世纪，旱涝灾害更加。在全球变暖的背景下，预计该区未来气候趋向于暖湿，但不排除暖干的可能性。  相似文献