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本文介绍了陕北气区陕35井第一次下光油管(即不带封隔器)酸化的施工情况,并结合该地区的地层压力特征分析了光油管酸化施工的可行性及应用限度。     

渤海湾盆地复式油气聚集带高勘探程度区进一步挖潜的领域

渤海湾盆地复式油气聚集区经过了40年的勘探,目前已进入了高勘探程度区.油气聚集的复杂规律表明,渤海湾盆地仍具有巨大的资源潜力,进一步挖潜的领域非常广阔.以第三系为烃源岩的含油气层系的勘探精度仍有待于进一步提高,同时必须将以古生界、中生界和中上元古界为烃源岩的含油气层系作为今后挖潜的重要领域.渤海湾盆地任何层系都可能形成和聚集油气,因此仍有多种复杂的油气藏类型尚待进一步认识和发现.     

鄱阳湖湖底沉积物放射性水平

本文报道了1985年鄱阳湖湖底沉积物放射性水平的调查结果。沉积物中 U、Th、~(226)Ra、~(40)(?)和~(137)Cs 的比活度分别为64.8、67.9,58.9、676.1和3.5Bq/kg;用~(137)Cs 测龄方法作了沉积物泥芯垂直深度的年代定位,由此得知1985—1958年对应深度沉积物中 U、Th、~(226)Ra 和~(40)K 的比活度与1957—1930年对应深度沉积物比较无显著性差异;U、Th 和~(226)Ra 的浓集因予分别为5.2×10~413.9×10~4和4.8×10~4L/kg。     

乌江流域大型复杂水电站群联合优化调控关键技术及其应用研究

根据乌江流域总体规划、长江三峡以上防洪要求、南方电网运行特点、乌江流域水文特性等,贵州乌江水电开发有限责任公司组织开展了乌江梯级水库优化调度和发电优化控制的基本理论研究,并根据该研究建立了乌江流域水电站群联合优化调控系统,经过一系列优化调度规则、方法、措施在系统中的应用,实现了节水增发电的目的,取得了良好的社会经济效益。     

How Non-native Species in Lake Erie Influence Trophic Transfer of Mercury and Lead to Top Predators

Lake Erie's food web has been dramatically modified by exotic species. Both exotic dreissenid mussels and the round goby Neogobius melanastomus have shifted the food web from a pelagicbased to a benthic-based one, potentially creating a new pathway for contaminant transfer to top predators. Before the invasion of round gobies, few predators of dreissenids occurred in Lake Erie, allowing contaminants to be confined to these benthic organisms. The invasion of the round goby has produced a new pathway through which these contaminants can enter the food web. To characterize heavy-metal transfer through this new food web and to assess risk to humans, water, surficial sediment, dreissenid, round goby, and smallmouth bass Micropterus dolomieui samples were collected at three sites during summers, 2002 and 2003, and analyzed for total lead (Pb), total mercury (Hg), and methyl mercury (MeHg). In addition, we compared smallmouth bass Pb and Hg concentrations to those measured in 1993/1994, before round gobies were prevalent. Pb biodiminished and MeHg biomagnified through the food web to smallmouth bass; patterns were similar among our three sites. Total Pb concentrations in smallmouth bass were higher before the incorporation of round gobies into their diet. We attributed this decline to changes in food web structure, changes in contaminant burdens in prey, or declines in sediment Pb concentrations in Lake Erie. By comparison, Hg concentrations in smallmouth bass changed little, before and after the round goby invasion, possibly due to a shift in diet that increased growth. Despite a decline in sediment Hg concentrations in Lake Erie, smallmouth bass continued to accumulate Hg at historical rates possibly because of their high consumption rates of benthivorous round gobies. As smallmouth bass continue to consume round gobies during their lives, their Hg concentrations may well continue to increase, potentially increasing the risk of Hg contamination to humans.     

柴达木盆地北缘侏罗系沉积环境演变及其石油地质意义

柴达木盆地北缘(柴北缘)东段大煤沟剖面侏罗系沉积层序发育完整。下侏罗统岩性以细砾岩、细—粉砂岩与炭质泥岩和页岩的不等厚互层为特征,其中大煤沟组一、二段与辫状河三角洲平原相关的湖沼相炭质泥页岩较发育,多含叶肢介、双壳类和植物等静水环境生物化石,沉积环境为辫状河三角洲—滨浅湖体系;由3个中期基准面升降旋回构成1个长期旋回。中侏罗统厚层河流—冲积相砂砾岩较发育,化石面貌以介形虫和植物为主,沉积环境为扇三角洲—滨浅湖体系,中上部发育较深湖相沉积;由9个中期基准面升降旋回构成1个长期旋回。不同时期和地区的化石与岩相分布特征反映侏罗纪沉积中心由西向东迁移。构造活动和气候是沉积环境的主要影响因素,但前者起重要的控制作用。早侏罗世潮湿气候下的辫状河三角洲平原为柴北缘提供了重要的生烃母质,但中侏罗世中晚期半干旱气候更有利于形成高品质的烃源岩。图5表1参18     

核磁共振测井在致密含气砂岩中的应用

通过对核磁共振测井的T₂谱及其T₂截至值的合理选取，解释并获得了鄂尔多斯盆地西缘上古生界山西组、石盒子组致密砂岩储集层的总孔隙度、有效孔隙度、毛细管束缚水体积、可动水体积及渗透率等参数，据此预测的储集层孔隙结构特征与岩心分析测试结果很吻合。研究还发现，致密含气砂岩的T₂谱具有分布范围窄-中等，波形及差谱分析谱位置明显后移、分布中等、呈单峰的典型特征。结合常规测井资料，综合研究了致密砂岩储层特征及其含气层的测井响应。经测试验证，致密含气砂岩储层的核磁共振测井解释结果十分可靠，表明核磁共振测井可用于该区致密含气砂岩复杂储集层评价。     

Psychrotrophic violacein-producing bacteria isolated from Lake Winnipeg,Canada

Violet and purple bacterial pigmentations are uncommon when considering strict aerobes. Here we report discovery of two novel isolates, P102 and P117 from the freshwater Lake Winnipeg, each with violet to deep purple colony colouration. The relationship between pigment production and growth was investigated under different conditions, including a variety of carbon sources, pH, and temperatures. The violet compounds were purified using polar organic solvents, and then structurally characterized via mass spectrometry and nuclear magnetic resonance to be violacein and deoxyviolacein. Strain P117 produced higher concentrations of the darker pigment deoxyviolacein, which resulted in a deeper hue of violet than in cultures of P102. Strain P102, synthesized violacein maximally in liquid rich organic medium at pH 8 and 20 °C, and had 99.3% sequence similarity to the 16S rDNA from Janthinobacterium lividum. Strain P117, related to Massilia violaceinigra sharing 99.2% 16S rDNA sequence similarity, also produced violacein at similar optimal conditions, but developed higher concentrations of pigment at 15 °C. Culture-based methods found that violacein producers composed 0.001% or 0.023% CFU of environmental heterotrophic populations using BG-11 and potato-based media, respectively. Culture-independent high-throughput ribosomal 16S V4 sequencing of environmental DNA was used to detect Gram-negative species known for their production of violacein. Of all bacterial and archaeal sequences present during the fall in littoral waters and sediment of Lake Winnipeg, 5.5% and 6.3%, respectively, belonged to species that have similar pigment, demonstrating the scarcity of violacein producers in this aquatic freshwater system.     

Foredune dynamics at a Lake Michigan site during rising and high lake levels

On Great Lakes dunes, the link between foredune dynamics and coastal processes is seen in dune responses to changing lake levels. This paper investigates foredune dynamics during a recent period of rising and high lake levels. The study location was an active foredune in P.J. Hoffmaster State Park on the east coast of Lake Michigan, where field data were collected from 2000 through the final destruction of the foredune by wave removal in November 2019. Foredune dynamics were studied with erosion pins, direct observations, photographs, mapping, and on-site wind measurements. Regional climate and lake-level data were obtained from established data collection programs. The response of the foredune to rising lake levels was compared to several models of foredune behavior. During the study, the Lake Michigan-Huron level rose 1.89 m from January 2013 to July 2020. After an early transitional period, foredune activity was characterized by scarp retreat (4–19 m per year) and dune narrowing from 2014 to 2019. When the foredune completely disappeared in November 2019, erosion/scarping began on the next landward dune. The foredune activity fits Olson’s (1958) model for foredune growth and erosion through lake-level cycles. The foredune migration predicted by the revised Davidson-Arnott (2021) model of foredune response to relative water level rise did not occur, most likely because the rate of lake-level rise was too high. The six years of foredune narrowing before wave erosion started affecting the next landward dune represent a time-lag in Lake Michigan dune history models of increased dune activity during high lake-level stands.     

Wild juvenile salmonid abundance in Wisconsin tributaries indicates limited contributions to Lake Michigan fisheries

Natural reproduction of salmonids occurs in many Lake Michigan tributaries, yet little is known about abundance and the potential contribution of wild fish hatching in Wisconsin tributaries. The objectives of our study were to determine if: 1) abundance of wild juvenile salmonids (primarily adfluvial rainbow trout, Oncorhynchus mykiss, referred to as steelhead) varied among selected Wisconsin streams based on available spawning and age-0 habitat; 2) stream temperature regimes could limit survival of juvenile salmonids, and 3) wild juvenile salmonids outmigrate from Wisconsin tributaries into Lake Michigan or larger tributaries. In 2016 and 2017, juvenile salmonid abundance was estimated in six Wisconsin tributaries to Lake Michigan by multiple-pass depletion sampling using backpack electrofishing. Habitat assessments included steelhead redd surveys, age-0 habitat surveys, and stream temperatures were monitored using in-stream loggers. Passive integrated transponder (PIT) tagging and PIT antennas were used to detect outmigration from three streams (Willow, Stony and Hibbard creeks). Population estimates for individual streams ranged from 75 to 2276 for juvenile steelhead and from 0 to 243 for juvenile coho salmon, Oncorhynchus kisutch. No correlation was detected between juvenile steelhead abundance and quality age-0 habitat. Stream temperatures rarely exceeded the thermal limit for steelhead (27 °C). Outmigration rates for three streams ranged from 0.6% to 3.1%, but these estimates were considered minimum values. Low abundance of wild juvenile steelhead and coho salmon alone suggest that the contributions of these tributaries to Lake Michigan fisheries are likely small. Furthermore, relying on returns of wild steelhead produced in these streams is probably insufficient to maintain stream fisheries.