稳定碳、氮同位素在河流系统研究中的应用

对天然存在的稳定碳、氮同位素在河流系统中的有机物质(POM和DOM)来源、转换和运移规律及其与沿岸生态系统的关系、河口区不同来源颗粒有机质的混合过程、河流系统中富营养化的污染来源和土壤中的微生物过程、系统中的营养行为和食物来源途径以及河流有机物质在陆架上的分配、积累和运移规律的应用研究作了较为系统的论述。     

Human impacts, climate change, and aquatic ecosystem response during the past 2000 yr at Lake Wandakara, Uganda

Analyses of carbon and hydrogen isotope ratios of terrestrial leaf waxes and the carbon and nitrogen abundance, ratio, and isotopic composition of bulk sediments from Lake Wandakara, a crater lake in western Uganda, East Africa, document human and climatic controls on the aquatic system and on the surrounding terrestrial vegetation during the past two millennia. Our data indicate that Wandakara was a relatively stable, productive lake surrounded by C₃ vegetation from AD 70 to 1000. Abrupt changes in the δ¹³C of terrestrial leaf waxes indicate a series of abrupt shifts in the relative abundance of C₃ and C₄ vegetation caused by a combination of climate change and human activities around Wandakara beginning at AD 1000. Abrupt shifts in bulk sediment organic geochemistry, particularly C/N ratios and δ¹⁵N, indicate that human activities at this time caused permanent changes in the limnology of Lake Wandakara, including eutrophication. Our results suggest that the biogeochemistry of Lake Wandakara was more sensitive to shifting human impacts than to climate variations during the past millennium, highlighting the importance of understanding the intensity of pre-colonial human impacts on Africa's aquatic ecosystems.     

开发水泥工业新技术，争创节能减排新水平

我国在国民经济持续高速发展的同时也承受着能源消耗和环境恶化的巨大压力,水泥行业是耗能、排污大户,面临技术升级和节能减排的重大课题和历史任务。天津水泥工业设计研究院有限公司一直致力于我国水泥工业开发和提供新技术和新装备,推动我国水泥工业走资源节约型、环境友好型的新型工业化道路。近年来的新成果主要在新一代烧成节能技术、无球磨粉磨节能技术、余热发电技术、水泥工业处置工业废弃物和城市生活垃圾以及减少水泥生产有害粉尘和气体的排放等方面,代表了我国新型干法水泥生产技术和装备的先进水平。     

水—气二相流及污染物运移数值模拟研究

本文通过对近些年来水－气二相流数值模拟进展情况的分析,总结了在水－气二相流模拟过程中,各个主要参数或物理过程的数学概化方法,以及近年来在求解水气二相流方程和污染运移方程的方法上的改进情况。并在此基础上提出了需进一步研究解决的问题。     

Physils and organic matter-base palaeoenvironmental records of the K/Pg boundary transition from the late Cretaceous-early Palaeogene succession of the Um-Sohryngkew River section of Meghalaya,India

A continuous, shallow marine succession of the Um-Sohryngkew River section is distinct as it contains late Maastrichtian-early Danian planktonic foraminiferal zones and the K/Pg boundary, although K/Pg transition events remain inconclusive. Physils divide entire succession in to lower, middle and upper sub-divisions and represent anomalous values of redox-sensitive elements (δCe, La/Yb and Gd/Yb) in biozone CF3. Organic matter when analyzed show TOC and C spikes in biozone CF3. Illite thermometry also revealed sudden increase in the palaeo-temperature (>140 °C) for yellowish brown 1–2 mm thick organic rich clay layer in biozone CF3. Interestingly, conspicuous increase in the short chain n-alkanes and fatty acids is observed in the biozone CF3, although, long chain n-alkanes (C₂₇–C₃₃) derived from terrestrial plants show low abundance throughout the succession.High amount of combustion derived fluoranthene, pyrene, chrysene, benzo(a) anthracene PAH compounds found in the biozone CF3 are analogous to those reported from the K/T boundary sections of Stevns Klint, Gubbio, Woodside Creek and Arroyo el Mimbral. The pyrolitic signatures of these organic macro-molecules reflect global fire, caused distress to biota (during the deposition of biozone CF3 layer) which is coincidental with the well documented Ce anomaly layer, but, preceded by planktonic foraminiferal change in biozone P0 and PGE anomaly bearing layer in the biozone CF2. These organic macro-molecules reflect global fire, induced by the heat supplied by the late Cretaceous Abor and/or Deccan extrusions perhaps linked with the K/T transition events as later initiated prior to the K/Pg boundary, however, the main episode of Deccan volcanic activity occurred ∼300 ky earlier or at the K/Pg boundary itself. The deposition of 1–2 mm thick, yellowish brown, smooth (with conchoidal fracture) pyrite nodules and micro-spherules bearing organic rich clay layer marked with the decrease in the carbonate content (2.43%) that lies at the contact between the silty mudstone and grey calcareous shale located in the biozone CF3 of this succession coincides with the first appearance of Pseudoguembelina hariaensis representing age of 66.83–65.45 Ma is also related to the India’s collision with the Eurasia and Burma andextrusion of Abor volcanic.These events also endorse succeeding events such as anomalous concentration of platinum group of elements and concentration of spherules during biozone CF2, which are other end Cretaceous events before the advent of the K/Pg boundary.     

高温微生物铁还原条件下绿脱石对有机质的保存作用研究

粘土矿物在地表环境中广泛存在,并且与环境中的有机质紧密结合在一起。前人的研究发现,粘土矿物的可膨胀层间域可以有效地保存有机质,防止其在微生物诱导的氧化还原环境的波动的环境中被矿化。然而这一过程在高温条件下是否同样成立尚属未知。本文选取一种代表性有机质12-氨基十二酸(ALA)与典型含铁粘土矿物绿脱石(NAu-2)合成有机质-粘土矿物复合体,在两株高温-超高温铁还原细菌的作用后,通过多种水化学和矿物学的表征手段,研究其矿物结构的变化、有机质的结合稳定性和脱附情况。结果发现细菌对绿脱石结构铁的还原过程中造成的矿物结构的破坏(还原性溶解)是控制ALA从NAu-2中脱附的主要原因。高温条件也会略微促进ALA从NAu-2的层间域中脱附出来。总体来说,受限于微生物对结构铁的还原程度(30%),最终在结构铁还原反应结束后还是有相当大量的ALA在层间保存了下来。这一结果证明了粘土矿物的层间域在高温条件下同样也能够作为有机质保存的有效场所。     

GMS模型的水文水质模拟应用研究

GMS模型是应用广泛的地下水水文模拟系统。以昆山市某古镇为研究区域,采用GMS模型对其水文水质进行模拟研究。通过用概化方法建立水文地质概念模型和数学模型,用反演迭代方法矫正模型的主要参数等过程,分别用MODFLOW和MT3DMS模块模拟和预测了研究区水文水质状况和污染物迁移趋势。数据对比结果显示,模拟值与检测值基本一致,表明校正后的GMS模型能较好再现地下水流系统特征,并能应用于流域污染物扩散过程的模拟和预测中,对地下水污染物的迁移趋势进行分析,以便及时采取有效措施控制污染源。     

Dissolved organic matter tracers reveal contrasting characteristics across high arsenic aquifers in Cambodia:A fluorescence spectroscopy study

Organic matter in the environment is involved in many biogeochemical processes,including the mobilization of geogenic trace elements,such as arsenic,into groundwater.In this paper we present the use of fluorescence spectroscopy to characterize the dissolved organic matter(DOM)pool in heavily arsenicaffected groundwaters in Kandal Province,Cambodia.The fluorescence DOM(fDOM)characteristics between contrasting field areas of differing dominant lithologies were compared and linked to other hydrogeochemical parameters,including arsenic and dissolved methane as well as selected sedimentary characteristics.Absorbance-corrected fluorescence indices were used to characterize depth profiles and compare field areas.Groundwater fDOM was generally dominated by terrestrial humic and fulvic-like components,with relatively small contributions from microbially-derived,tryptophan-like components.Groundwater fDOM from sand-dominated sequences typically contained lower tryptophan-like,lower fulvic-like and lower humic-like components,was less bioavailable,and had higher humification index than clay-dominated sequences.Methane concentrations were strongly correlated with fDOM bioavailability as well as with tryptophan-like components,suggesting that groundwater methane in these arsenic-prone aquifers is likely of biogenic origin.A comparison of fDOM tracers with sedimentary OM tracers is consistent with the hypothesis that external,surface-derived contributions to the aqueous DOM pool are an important control on groundwater hydrogeochemistry.     

地下水中有机污染物分析质量控制研究

建立了水中96种有机化合物的分析配套方案,包括吹扫捕集-气相色谱质谱法测定水中挥发性有机化合物,气相色谱火焰光度检测器测定水中有机磷农药,气相色谱电子捕获检测器测定水中有机氯农药和多氯联苯,高效液相色谱二极管阵列-荧光检测器联用测定水中多环芳烃。方法检出限满足中国地质调查局《地下水污染调查评价规范》的要求。同时对样品测试中质量控制方法进行研究,制定了一套行之有效的质量控制方案,质量控制结果满意。     

基于多元成土因素的土壤有机质空间分布分析

以陕西省蓝田县2013年667份土壤有机质样本为对象,运用GIS空间分析及遥感数字图像处理收集整理土壤类型、地形、植被等成土因子,利用多元线性回归分析集成所有成土因子对土壤养分进行空间分布预测。结果表明:通过分级统计均值定权法和像元线性拉伸法将所有成土因子统一为相对度量值,并根据成土因子与有机质含量的相关性显著程度进行因子取舍,有利于集成各类成土因子构建多元线性回归模型。预测结果定性分析表明:多元线性回归预测结果与kriging法预测结果在宏观上具有一致的空间分布趋势;但多元线性回归预测结果土壤有机质空间分布特征带有各种成土因子的变化特征,从视觉效果上,克服了传统插值法中存在的斑块状分布现象,更精细的描述了本区域内有机质空间分布趋势; MPE和RMS定量精度分析显示,在集成多元成土因素对有机质进行空间分布分析时,本文方法优于常用kriging插值法,该法可作为集成多元成土因子对土壤养分空间分布预测的有效方法。本区域内土壤有机质高值区域主要集中在地势低平、坡度缓和、湿度适中的农耕区,地势较高、坡度陡的山区有机质含量低。