Microplastic pollution in Yellow River,China: Current status and research progress of biotoxicological effects

This study aims to comprehensively assess the environmental risks of microplastics in the Yellow River, achieving the following results through comprehensive research. The average microplastic abundances in the river waters and sediments are 5358–654000 n/m³ and 43.57–615 items/kg, respectively, and there are fewer microplastics in water samples than in sediments. Microplastics in the study area can be divided into five types according to their occurrence morphologies, namely fragments, foams, films, fibers, and particles. The most widely distributed pollution types in sediments include debris, fibers, and particles. In contrast, fibers are the dominant type in water samples, accounting for 68.18% –98.93%. The chemical components of the microplastics include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride. The microplastics are in four colors, with white accounting for a higher proportion. The grain size of the microplastics in tributaries or lakes of the Yellow River is less than 2 mm, which makes them liable to enter organisms for enrichment. Furthermore, the sources of the microplastics are closely related to agricultural and industrial production and biological activities in habitats and exhibit seasonal and hydrological characteristics. The microplastics in the study area show the adsorption of metals and nonmetals to different degrees, which increases the pollution risks of heavy metals combined with microplastics. In addition, microplastics can accumulate in organisms in the Yellow River and cause physical, biochemical, and other damage to aquatic organisms, thus further posing carcinogenic risks to human beings. Therefore, it is necessary to study, monitor, and control the pollution and effects of microplastics in the Yellow River, in order to provide theoretical references for the control of pollution and ecological risk of microplastics in the river.©2021 China Geology Editorial Office.     

延边地区成矿地质条件及金矿找矿

延边地区是吉林省重要产金区之一。金矿与中元古界色洛河群、下古生界五道沟群、三叠－侏罗纪火山岩系及华力西－燕山期中酸性侵入岩、次火山岩和ＮＥ、ＮＷＷ向深断裂带及ＥＷ、ＳＮ向断裂构造、火山构造密切相关。具有较好的找矿前景。     

海水制盐的气象条件分析

通过对广西防城港市企沙盐场1996~2005年近10年的原盐产量与气象条件的关系进行分析,得出影响海水制盐的主要气象因子是降水、蒸发量、气温、大风,并提出各种气象条件下的生产对策及气象部门对盐业服务的思路和设想。     

Residual ultimate strength of steel plates with longitudinal cracks under axial compression–experiments

The main objective of the present study is to examine the residual ultimate strength characteristics of steel plates with cracking damages under axial compressive actions through experimental investigations. The present study is a sequel of the author's previous paper (Paik, J.K., Satish Kumar, Y.V., Lee, J.M., 2005. Ultimate strength of cracked plate elements under axial compression or tension. Thin-Walled Structures, 43, 237–272). In contrast to the previous paper which dealt with transverse cracks located in the direction normal to the axial loading direction, the present paper is concerned with longitudinal cracks which are located in parallel to the axial loading direction. Similar to the previous paper, the orientation/location and size of cracks inside the plates are varied for the present experimental investigations. The details of experimental results are documented. The database and insights developed from the present work will be useful for cracking damage-tolerant design of steel-plated structures and also for condition assessment or health monitoring of aging steel-plated structures.     

深圳市近年空气质量与气象条件的关系

利用近4年深圳市大气污染物的质量浓度资料和天气型统计,分析了大气污染物浓度变化与本地天气特征、气象要素的关系,总结造成深圳市空气质量夏优冬差的天气气侯原因,归纳出850hPa与地面天气型的不同组合对空气质量的影响,并由此给出各种影响的逐月分布;最后根据大气污染物浓度逐年的概率密度分布曲线和空间分布描述了近年深圳市空气质量的年际变化和空间分布特征。     

从苏北盆地黄桥和朱家墩气田成藏特征看江汉盆地勘探前景

苏北盆地发育了“黄桥型”和“朱家墩型”两类气藏。黄桥型气藏为断裂—裂缝型复合圈闭,不受层位控制,其气源为具有晚期生烃潜力的海相烃源岩重新深埋后再次生成的烃类气和经多期次火成岩侵入和喷发产生的大量CO2。朱家墩型气藏主要是海相烃源岩深埋后二次生烃形成晚期烃源充注、向上运移到白垩系成藏,属“古生新储”型。江汉盆地的成藏条件与苏北盆地具有可对比性,其中的江陵凹陷具备形成黄桥型气藏的条件,而沔阳凹陷则具备形成朱家墩型气藏的条件。江陵凹陷与苏北黄桥气田在构造演化、储盖条件、烃源、岩浆活动等方面均具有相似性,且前者的成藏条件更显优越。沔阳凹陷与苏北盐城坳陷东南部的烃源岩基础数据具有可比性,古生界均具备多套烃源岩层,且均表现为高演化特点,晚期生烃潜力也相似,其烃源为晚期生烃的古生界和上三叠统—侏罗系。     

某化工厂区地下水氯化物运移研究

在调查掌握某化工厂区地下水氯化物指标的基础上,得出了该化工厂区地下水中氯化物为污染指标。查明了该化工厂区水文地质条件,建立了该区水文地质概念模型,采用模型计算方法,预测了该化工厂区地下水流场的变化,对工厂企业采取治理措施后的地下水中氯化物浓度进行了分析与预测,对治理措施的有效性进行了评价。结果表明:模型计算结果能够反映该区地下水中氯化物的变化规律,在工厂企业采取污染防治措施之后,该区内地下水中氯化物浓度大幅下降,计算结果与实际监测结果相符,模型可预测该化工厂区地下水氯化物发展趋势,对该化工厂区地下水污染防治具有重要的实际意义。     

Sediment distribution characteristics and environment evolution within 100 years in western Laizhou Bay,Bohai Sea,China

This study is about the reconstruction of fluvial origins based on the grain size distribution of sediment deposits in the western Laizhou Bay, Bohai Sea, China. Thirteen sediment cores were selected to research sediment characteristics using the Sahu discriminant formula, C-M diagram, and Folk method. The results showed: (1) Bounded by the Guangli River estuary, the north sediment was affected by the water and sand flowing from the Yellow River during different periods. The south sediment came from multi-source rivers under the influence of the Xiaoqing River, Mihe River, and other coastal rivers; (2) the deposited sediments were dated by a clear historical record of the branched channel oscillation combined with the characteristics of the diversion channel, erosion, and regression. The subaqueous delta overlapped during several Yellow River channel runs (1897–1904, 1929–1934, 1938–1947, 1947–1953, 1976–1996) and the deposited sediment facies changed (the north tidal flat-abandoned subaqueous delta-lateral delta-delta front); (3) the deposited sediment characteristics can be revealed by studying the branched diversions of the Yellow River and coastal multi-rivers of the past one hundred years.     

矿渣型泥石流发育特征及危险性评价

大西岔沟地质环境复杂,节理、裂隙发育,在各支沟及主沟中,填埋了36万多方以碎石土为主的高、陡矿渣堆.这些矿渣以台阶状层叠堆放的形式填满整个沟谷,严重堵塞水路,并且矿渣堆的稳定性较差,透水性较好,再加上暴雨雨量大,汇流集中,大西岔沟已具备了泥石流灾害爆发的条件.结合洪峰流量对大西岔沟泥石流的启动条件进行分析,极容易发生泥石流.对于像大西岔沟的这种矿渣型泥石流,其主要形成水石流,具有固体物源补给方量大、产流区集中、容易启动、流通距离短和破坏性大的发育特征,其固体物质补给主要以冲、洪沟的侧蚀、揭底补给、渣堆失稳和坡面漫流冲刷补给为主.在此基础上,提出了以排导和固渣相结合的治理方案,即在沟谷中修建大量的排水沟,能第一时间排走洪水,同时对渣堆进行放坡处理,以增加渣堆的自稳能力.     

雄安新区白洋淀流域平原区1:50 000水文地质数据集

本数据集依托2016年中国地质调查局"白洋淀流域平原区1：50 000水文地质调查"项目,在充分收集以往地质资料的基础上,开展了隶属雄安新区规划建设核心区域的安新县幅、雄县幅1：50 000水文地质及专项生态环境地质调查工作,编制了标准的1：50 000水文地质图及说明书,依照行业规范将此次调查获取的数据建立了1：50 000水文地质调查成果数据集。本数据集包含8种数据类型,包含895个基础调查数据,22个野外地质综合调查点数据,82个地层岩性界限调查点数据,540个水文地质调查点数据,22个环境地质调查点数据,12个钻孔基本情况数据,71个抽水试验综合成果数据,2 200个野外照片数据,共计3 844个数据。本数据集对认识白洋淀及周边区域水文地质条件,评价地下水资源,以及研究湿地生态功能退化等生态地质环境问题具有一定的参考意义。