大通湖及东洞庭湖区生物体重金属的水平及其生态评价

于2005年11月采集了大通湖及东洞庭湖区湖水和水生生物样品,并测定了水和水生生物样品中重金属(Cd、Pb、Hg、As)的含量,并对湖区生物体重金属进行了污染评价.研究结果表明,大通湖及东洞庭湖区湖水中重金属含量较小,绝大部分采样点水质都属于国家Ⅰ类水标准;水生生物体内CD、Pb含量为虾＞螺＞鱼,Hg的含量为鱼＞螺＞虾,As的含量为螺＞虾＞鱼;而鱼类重金属含量则为底栖鱼类＞中上层鱼类,肉食性鱼类＞植食性鱼类.大通湖及东洞庭湖区生物体中CD、Pb的污染指数为虾＞螺＞鱼,Hg的污染指数则为鱼＞螺＞虾,As的污染指数则为螺＞虾＞鱼.     

Recent trends of extreme precipitation indices in the Iberian Peninsula using observations and WRF model results

Spatial and temporal distributions of the trends of extreme precipitation indices were analysed between 1986 and 2005, over the Iberian Peninsula (IP). The knowledge of the patterns of extreme precipitation is important for impacts assessment, development of adaptation and mitigation strategies. As such, there is a growing need for a more detailed knowledge of precipitation climate change.This analysis was performed for Portuguese and Spanish observational datasets and results performed by the Weather Research and Forecast (WRF) model forced by the ERA-Interim reanalysis. Extreme precipitation indices recommended by the Expert Team for Climate Change Detection Monitoring and Indices were computed, by year and season. Then, annual and seasonal trends of the indices were estimated by Theil-Sen method and their significance was tested by the Mann-Kendal test. Additionally, a second simulation forced by the Max Planck Institute Earth System Model (MPI-ESM), was considered. This second modelling configuration was created in order to assess its performance when simulating extremes of precipitation.The annual trends estimated for the 1986–2005, from the observational datasets and from the ERA-driven simulation reveal: 1) negative statistically significant trends of the CWD index in the Galicia and in the centre of the IP; 2) positive statistically significant trends of the CDD index over the south of the IP and negative statistically significant trends in Galicia, north and centre of Portugal; 3) positive statistically significant trends of the R75p index in some regions of the north of the IP; 4) positive statistically significant trends in the R95pTOT index in the Central Mountains Chain, Leon Mountains and in the north of Portugal.Seasonally, negative statistically significant trends of the CWD index were found in Galicia, in winter and in the south of the IP, in summer. Positive statistically significant trends of the CWD index were identified in the Leon Mountains, in spring, and in Galicia, in autumn. For the CDD index, negative statistically significant trends were seen in Valencia, in the spring, and, in Galicia and Portugal (north and centre), in summer. Positive statistically significant trends of the CDD index were found: in the east of the IP, in the winter; in the Cantabrian Mountain, in the spring; and, in the south of the IP, in summer. Regarding to the R75p index, negative statistically significant trends were found in Galicia, in winter and positive statistically significant trends in the north of Portugal, in spring and in the Central Mountains Chain and north of Portugal, in autumn. For the R95pTOT index, negative statistically significant trends were found over the Sierra Cuenca and Sierra Cazorla, in winter and positive statistically significant trends were found over the Sierra Cebollera, in winter and in Castile-la Mancha region, in spring.The results of the annual and seasonal trends of the extreme precipitation indices performed for observational datasets and the simulation forced by ERA-Interim, are similar. The results obtained for the simulation forced by MPI-ESM are not satisfactory, and can be a source of criticism for the use of simulation forced by MPI-ESM in this type of climate change studies. Even for the relatively short period used, the WRF model, when properly forced is a useful tool due to the similar results of Portuguese and Spanish observational datasets and the simulation forced by ERA-Interim.     

淮河流域焦岗湖水质参数时空变化及影响因素

焦岗湖是淮河左岸一个天然湖泊,集防洪、灌溉、养殖、旅游等多种功能于一体.利用焦岗湖4个季节水质监测数据,运用Kriging方法,分析焦岗湖水质参数的时空变化及影响因素.结果表明:由于受水文季节变化过程及人类活动等综合影响,焦岗湖水质参数在时间及空间上均存在一定差异.从时间变化来看,夏季透明度较低、秋季较高;溶解氧浓度在春、冬季显著高于夏、秋季;总氮、总磷浓度与高锰酸盐指数均表现为夏季最高、秋季最低.从空间变化来看,4个季节的透明度空间差异较为显著;溶解氧浓度在春、冬季空间分布较为均匀,夏季呈现中心高周围低的变化趋势,秋季则表现为西高东低;总磷浓度春季分布较为均匀,夏、秋及冬季则呈西高东低之势;高锰酸盐指数在春、秋季节呈现东高西低之势,夏季高浓度主要集中在湖区北部,冬季浓度变化不大.     

云南地区大震活动规律研究

云南地区处于印度板块与欧亚板块中国大陆碰撞带的东缘,地壳运动剧烈,活动块体特征明显,中强以上地震频发,是研究大震活动规律的理想场所。通过过去一个世纪的6.7级以上地震活动的时空分布以及地震动力分析认为,云南地区存在的4个具东西交替活动特征的地震活跃期,可能是东、西部各自地震活跃与平静过程叠加的结果,100a左右可能出现1次东、西部同时爆发大震的时段;云南地区地震活动与外围地区存在较好的呼应关系,安达曼-缅甸弧形带的巨震活动对云南地区地震活跃期的启动有一定的指示意义,而云南东部强震也与四川西部大震密切相关,四川大震活动往往滞后于云南地区;中强地震连发—平静—首发大震可能是云南以东部为活动主体的地震活跃期的启动模式。这些认识对云南地区大震预测、地震机理以及板缘动力学研究会有所帮助     

陕西洛川不同时代黄土中的碳酸钙的沉积速率及其在地质年代测定中的意义

选择地处西北半干旱区、又具有代表性的黑木沟标准剖面,逐一测试其土层中的碳酸钙与干容重,进而由相关参数推算各土层的碳酸钙的沉积速率(V,下同),这是笔者的尝试。结果表明,该剖面中的碳酸钙的沉积速率,均有自下而上递增的趋势,各层总平均速率为0.20g/cm2·103a     

Structure and Significance of S-wave Velocity and Poisson’s Ratio in the Crust beneath the Eastern Side of the Qinghai-Tibet Plateau

The receiver functions of body waves of distant earthquakes obtained for the regions beneath 41 digital stations (Lhasa and GANZ in Tibet, Mandalay and Rangoon in Myanmar, SHIO in India, CHTO in Thailand, and station network in Sichuan and Yunnan) were used to invert for S-wave structure in the crust and upper mantle in Sichuan, Yunnan, and their surrounding areas. Meanwhile the distribution characteristics of the Poisson’s ration and the crustal thickness in Sichuan and Yunnan areas were also obtained. Results indicate that the depth of Moho beneath the eastern side of Qinghai-Tibetan plateau varies strikingly. It is obvious that the greatest changes in crustal thickness occur in a north-south direction. The crustal thickness decreases from north to south, being as thick as 70 km in eastern Tibet, the northern portion of our area of interest, and less than 30 km in Chaing Mai and Rangoon, the southern portion of our area. There are, however, exceptions regarding the trend. The thickness exhibits an east-west variation trend in the area from Ma’erkong-Kongding in Sichuan to Lijiang in Yunnan. In general the Jinpingshan-Longmenshan fault and Anninghe fault can be taken as the boundaries of this exception area. The thickness in Kongding in the west is 68 km, while it is only 39 km in Yongchuan in the east. Moreover the Poisson’s ratio values in the blocks of central Sichuan and Sichuan-Yunnan Diamond are high, and a low velocity layer in the crust of this area can be obviously detected. The distribution characteristics of the high Poisson’s ratio and the low velocity of the crust in this block correspond to the tectonic structure, being in contrast with the surrounding areas. Combining with the distribution features of the modern tectonic stress field, it is deduced that the Sichuan-Yunnan area is probably the channel through which the materials of the lithosphere flow eastward.     

Accumulation of trace elements in harp seals (Phoca groenlandica) from Pangnirtung in the Baffin Island, Canada

Nineteen trace elements were determined in liver, muscle, kidney, gonads, and hair of 18 harp seals (Phoca groenlandica) from Pangnirtung in the Baffin Island, Canada. Concentrations of V, Mn, Fe, Cu, Mo, Ag, and Hg in the liver, Co, Cd, and Tl in the kidney, and Ba and Pb in the hair were significantly higher than those in other tissues. Significant positive correlations between Hg concentrations in the hair, and liver, kidney and testis imply usefulness of the hair sample for non-destructive monitoring of Hg in the harp seals. It is suggested that whereas Hg preferentially accumulates in the liver, the accumulation in other tissues is induced at higher hepatic Hg levels. In contrast, Se may not be accumulated in other tissues compared with the liver even at higher hepatic Hg levels because of the presence of excess Se for Hg detoxification in other tissues.     

A history of British seismology

The work of John Milne, the centenary of whose death is marked in 2013, has had a large impact in the development in global seismology. On his return from Japan to England in 1895, he established for the first time a global earthquake recording network, centred on his observatory at Shide, Isle of Wight. His composite bulletins, the “Shide Circulars” developed, in the twentieth century, into the world earthquake bulletins of the International Seismological Summary and eventually the International Seismological Centre, which continues to publish the definitive earthquake parameters of world earthquakes on a monthly basis. In fact, seismology has a long tradition in Britain, stretching back to early investigations by members of the Royal Society after 1660. Investigations in Scotland in the early 1840s led to a number of firsts, including the first network of instruments, the first seismic bulletin, and indeed, the first use of the word “seismometer”, from which words like “seismology” are a back-formation. This paper will present a chronological survey of the development of seismology in the British Isles, from the first written observations of local earthquakes in the seventh century, and the first theoretical writing on earthquakes in the twelfth century, up to the monitoring of earthquakes in Britain in the present day.     

强地震附近视电阻率各向异性变化的原因

讨论了强地震、孕震晚期阶段、震源区及附近介质的物理变化过程,证明了视电阻率变化最显著的方向与最大加载方向之间的正交关系,建立了真、视电阻率各向异性变化与裂隙率ν、骨架电阻率ρ_o、饱水裂隙电阻率ρ_f的本构关系,解释了视电阻率各向异性变化的原因.研究认为：在强地震孕震晚期阶段,在震源区及附近地壳近地表的较深部,介质微裂隙发育,其走向沿最大主压应力方位优势取向,低阻水充填微裂隙,导电通道连通,引起最大主压应力方向真电阻率变化最显著的真各向异性变化,从而产生垂直主压应力方向视电阻率变化最显著的视各向异性变化,低阻水在其物理过程中起了显著作用.     

国际医用磁共振会议综述

本文介绍了国际医用磁共振协会及其主办的国际会议情况,即ＩｎｔｅｒｎａｔｉｏｎａｌＳｏｃｉｅｔｙｆｏｒＲｅｓｏｎａｎｃｅｉｎＭｅｄｉｃｉｎｅ－ＩＳＭＲＭ。该协会代表了世界上医用磁共振成像方面的最高水平,从第４次年会开始,会议在每年的４月份进行。本文作者参加了１９９７年在加拿大温哥华召开和１９９８年在澳大利亚悉尼召开的年会。会议主要讨论的题目包括功能磁共成像（ｆＭＲＩ）,结构磁共振成像（ａＭＲＩ）波谱成像（ＭＲＩ／Ｓ）和血管造影等方面的内容,以及磁共振成像技术协会方面关于诊断方法,显像增强剂技术,磁共振成像设备及其部件技术,以及数据处理方面的技术进步等课题。推动该领域发展的主要动力显然是对人类自身的研究和对疾病诊疗的需要,尤其对脑功能研究、功能性疾病的诊断和治疗的需要。但是磁共振成像目前在心脏、肺脏以至软骨方面的诊断已经有很大进步,在设备技术和数据处理方法方面的进步同样也是很快的。     

Stratification of selected hydrolytic enzyme activities in the sediment in two lakes in Finland

To investigate the stratification of hydrolytic enzyme activities and importance of subsurface layers in depolymerization of detritus biopolymers,nine hydrolytic enzyme activities involved in the cycling of carbon,phosphorus,nitrogen and sulphur were measured in various sediment layers and their extracts at Kylaniemi in Lake Saimaa in southern Finland and in Lake Ahvenjarvi in northern Finland. The results show that for each lake all nine hydrolytic enzyme activities were higher in all sediment layers than in comparable sediment extracts indicating that the major part of enzymes was bound to the sediment particles in all layers in both lakes.Carbohydratase,P-cellobiosidase,activities did not show any gradient with sediment depth at Kylaniemi in Lake Saimaa indicating that there was rapid turnover of carbohydrates in the entire sediment column.The activities of acetate esterase,butyrate esterase,phosphomonoesterase,aminopeptidase,N-acetyl glucosaminidase,sulphatase andβ-glucosidase in the deepest layers were 19-53%of those in the surface sediment indicating that depolymerization of biopolymers involved in the cycling of carbon,nitrogen,phosphorus and sulphur was substantial in subsurface sediment.     

Chlorinated hydrocarbons in fish-eating birds wintering in the Gdańsk Bay, 1981–82 and 1982–83

Seventy-four samples of adipose fat of 10 species of fisheating birds commonly wintering in Gdańsk Bay and one of little auk, a rare species in this area, have been analysed for residues of HCB, ΣBHC, ΣDDT and PCBs. Auks (guillemot, black guillemot and razorbill), which probably stay a whole year in the Baltic area, contained in their fat twice the level of PCBs as mergansers, and 5–6 times as much as in divers and grebes—birds which stay in the sea mainly after the breeding season. ΣDDT levels were somewhat higher but comparable in auks and grebes, and lower in mergansers and divers. ΣBHC and HCB levels were 3–4 times and 5–10 times higher, respectively, in auks than in birds from other families studied. When comparing residue levels found in adipose fat of birds taken during the wintering seasons of 1981–1982 and 1982–1983 with those taken in 1975–1976 or 1980–1981, an initially rapid, but in recent years a rather slow decline in ΣDDT level is detectable for grebes, mergansers and divers, and in the case of PCBs the residue levels fell slightly. In auks, the ΣDDT residue level fell by half, but remains rather stable in recent years, while there are only minor fluctuations in the residue level of PCBs.     

富营养化湖泊围隔中重建水生植被及其生态效应

水体富营养化导致水生植被衰退、蓝藻水华暴发、水质恶化和水生生态系统崩溃.恢复水生植被被认为是改善受损水体水质和提高其生态系统稳定性的重要手段.本研究通过构建大型围隔,根据水生植物的耐污程度及其对水质和底质等条件的需求,选取几种适宜的水生植物在围隔内进行移栽与群落构建,并以不移栽水生植物的围隔和围隔外水体作为对照.实验期间(2011年4月至2012年6月),围隔内移栽的几种水生植物全部存活,并建立了相对稳定的群落.同时还跟踪监测了3个处理组的水质情况,结果显示,移栽水生植物的围隔内水质明显优于围隔外,与未移栽水生植物围隔相比,也有很大程度的改善,其中移栽水生植物围隔内水体的总氮、铵态氮、总磷、水下消光系数相比于围隔外水体分别低30.55%、44.09%、36.04%和42.13%,相比于未移栽水生植物围隔内水体分别低5.96%、13.40%、6.70%和7.60%,透明度分别比围隔外水体和未移栽水生植物围隔水体高74.59%和8.70%,浮游植物生物量也大大低于围隔外,而浮游动物生物量却明显高于后者.此外,实验后移栽水生植物围隔内沉积物氮、磷含量及其间隙水总氮、总磷、铵态氮浓度明显低于围隔外和未移栽水生植物围隔.研究表明,在富营养化浅水湖泊中通过建立围隔进行合理的群落配置,进而逐步恢复水生植物是完全可行的,而水生植物恢复后加强对其管理和维护至关重要.     

Can a pollution event be detected using a single biological effects monitoring method?

The trends of malformation prevalence in embryos of dab, Limanda limanda, in the southern North Sea after the year 1990 mirrored the drop in major pollutants in the rivers draining into the German Bight. Despite this general decline, we detected a pollution event in the southern North Sea in winter 1995/1996 employing the prevalence of malformations in pelagic dab embryos as an indicator. An abrupt rise in malformation prevalence in the embryos of dab, corresponded to a dramatic increase in DDT levels in parent fish from the same area, indicating a hitherto unnoticed introduction of considerable quantities of DDT into the system.     

How can the uncertainty in the natural inflow regime propagate into the assessment of water resource systems?

The Canadian Rocky Mountain headwaters support the water resource systems of the Canadian Prairies. Significant variations in natural headwater contributions have been observed due to warming climate. Projecting future natural headwater flows under climate change effects, however, has large uncertainty. First, there are difficulties in climate modeling and downscaling in alpine regions. Second, streamflow modeling in mountainous areas is extremely challenging. There is therefore a need to understand the effects of uncertainty in the natural inflow regime, and in particular how this translates into uncertainty in representing the state and the outflow of water resource systems. Considering the Oldman River basin in Alberta, Canada, we synthesized different inflow regimes based on site/inter-site properties of the historical inflow regime. The water resources system was then conditioned on the synthesized inflow regimes to identify the mechanisms of error propagation from the headwater streamflows to the water allocations. The results show that the response of the water resource system to the uncertainty in the generated inflow regime depends on the system state, flow condition and the component of interest. Generally, the response of the reservoirs to the uncertainty in the estimated inflow regime is more significant in dry years, in particular during low flow conditions. The response at the system outlet is rather different, as the propagation of the headwater uncertainty is more significant during high flow conditions. Also, similar inflow estimates in terms of error and uncertainty may result in different error and uncertainty estimates in the simulated outflows; therefore, lower bias and uncertainty in estimating the regional inflow regime does not necessarily mean lower bias and uncertainty in simulating the streamflow at the outlet of the system. Our results provide improved understanding of uncertainty propagation through complex water resource systems, but also portray the need for better climate and hydrological modeling in the Rocky Mountains for improved water management in the Canadian Prairies, particularly in the face of uncertain climate futures. This will be crucial if the natural headwater inflows decline and/or the system faces drought conditions.     

The Impact of Deltas on the Mean Long-Term Water River Runoff

Specific features of the water balance of river deltas located in different geographic zones are discussed. Variations in the mean long-term water runoff in river deltas are estimated. As revealed, the river water runoff increases in the deltas located in subarctic, subequatorial, and equatorial regions, where precipitation exceeds evaporation, while the river water runoff decreases in deltas located in the temperate zone, subtropics, and tropics, where evaporation exceeds precipitation. It is noted that increase in water runoff is typical of the river deltas of the world as a whole.     

丹江口水库浮游植物群落时空变化及其与环境因子的关系

研究丹江口水库在完成高水位蓄水期间浮游植物群落的时空动态特征可为丹江口水库的水质保护与生态系统结构优化及健康管理提供一定科学依据。本研究基于2018—2020年的水库浮游植物监测数据,结合同期水库水体的理化参数,分析了丹江口水库浮游植物在不同年度、季度及空间的变化特征,以及影响浮游植物群落结构变化的主要环境因子。结果显示该区域共检测出浮游植物7个门类,其中蓝藻门、硅藻门、绿藻门、隐藻门为优势类群。2018—2020年浮游植物年均密度分别为1.96×10⁶、2.55×10⁶和5.07×10⁶ cells/L,呈现出逐年增高趋势。浮游植物季度密度表现为秋季>夏季>春季>冬季,在夏秋季节蓝藻门和绿藻门占优势,春冬季节硅藻门和隐藻门占优势,同时硅藻门在四季中均占据生长优势。空间上库区浮游植物密度明显高于支流,且汉江库区浮游植物密度高于丹江库区,其中蓝藻门和绿藻门主要在库区大量出现,而支流则以硅藻门和隐藻门为主。RDA分析显示,影响丹江口水库浮游植物的主要环境因子是水温,其次为化学需氧量、氨氮和总磷。在不同季节和...     

川滇地区地震动预测模型及其对2021年漾濞6.4级地震的适用性

随着川滇地区强震记录的不断增加,为了建立更符合该区域地震动特征的预测模型,文中基于该区域现有的地震动数据,通过随机效应回归模型建立适用于川滇地区的地震动预测模型;2021年5月21日,云南省大理州漾濞县发生6.4级地震,为了分析文中预测模型对漾濞地震的适用性,首先根据预测模型的适用范围选取合适的漾濞地震数据,计算真实记...     

末次盛冰期以来全球湿润状况的地质证据——全球古湖泊数据库及其湖水位变化的大尺度时空分析

介绍了正在建设中的全球湖泊数据库的情况,以及该数据库的水位资料所反映的晚更新世末期以来全球湿润状况的变化。通过大尺度湖水位变化的时空分析,结果显示当今湖泊水位状态较历史时期而言,位于低纬干旱或半干旱地区的湖泊水位较低,而中纬及高纬湿润地区的湖泊水位较高。自末次冰盛期以来,北美大陆中南部地区湖泊水位自高至低,反映出该地区气候条件由湿变干,至早、中全新世达最干旱。而在非洲及南亚季风地区,冷期偏干,暖期偏湿。特别是在早、中全新世的温暖时期,为历史上最湿润时期。北半球中纬度地带的气候干湿变化与北半球冰盖的存在及其消融导致的西风带的南北摆动有关;而北半球季风区在早、中全新世出现的高潮面与北半球夏季辐射的增加有密切联系。     

我国煤炭需求、探查潜力与高效利用分析

能源结构中全球大多数国家的主体能源是石油,而我国以富煤、贫油、少气为本土资源特点,煤炭是主体能源.目前随着我国改革开放的不断深入,社会经济快速发展,能源的需求大幅度增加.这使得对煤炭资源的勘探与开采必须不断深入,进入到第二深度空间日益紧迫.在开采过程中的难度随之增大,故必须引入当代高、新技术,防范灾害并提高煤炭综合利用效率.基于对我国主体能源-煤炭存储与需求的分析,本文将研讨以下几个问题:1)我国面临的能源形势与国策;2)当今对化石能源的需求、煤炭资源的生产和消费特点;3)全球和我国煤炭资源的生产、利用、需求、潜能和存在的问题;4)煤炭深部勘探、开采和高新技术的应用;5)我国煤炭的高效利用与其在能源结构中的不可替代;6)我国在发展进程中第二深度空间的煤炭需求乃必然轨迹.