大眼金枪鱼的资源现状

大眼金枪鱼的分布很广 ,在南、北纬 4 0°以内的太平洋、印度洋和大西洋均有分布 ,是金枪鱼渔业的重要捕捞种类之一。本文分别论述了大眼金枪鱼在大西洋、印度洋和太平洋的渔业概况、生物学特性、资源状况和管理对策。     

山东南部近海脊腹褐虾时空分布及其与环境因子的关系

脊腹褐虾(Crangon affinis)是山东近海众多鱼类的饵料生物,其分布与水深、海水底层温度等环境要素息息相关。根据2016年10月、2017年1、5和8月在山东南部近海4个航次获取的渔业资源及环境调查数据,分析山东南部近海脊腹褐虾的时空分布特征,运用广义加性模型研究脊腹褐虾的分布与水深、海水底层温度等环境因子间的关系。研究显示,脊腹褐虾CPUE分布呈现明显的季节特征,全年平均CPUE为2.07 kg/h,春季为2.43 kg/h,夏季为2.47 kg/h,秋季为1.18 kg/h,冬季为2.19 kg/h。水深和海水底层温度对脊腹褐虾分布影响显著(p0.01),脊腹褐虾CPUE与水深呈显著正相关,在水深80 m海域CPUE较高。海水底层温度为6～12℃时,脊腹褐虾CPUE与海水底层温度呈正相关,海水底层温度为12～20℃时呈负相关,最适宜海水底层温度约为12℃。     

青岛近海寿南小沙丁鱼Sardinella zunasi Bleeker繁殖生物学的研究

通过常规生物学测定、组织切片、电镜扫描观察等手段，分析了青岛近海寿南小沙丁鱼Sardinella zunasi Bleeker的繁殖群体构成和成熟与繁殖特征，并依此对该鱼种的资源保护措施提出了建议。     

胶州湾水域的营养盐

本文根据1983-1986年胶州湾水域理化环境的调査资料,对胶州湾及临近水域硝酸盐、亚硝酸盐、氨氮、磷酸盐和硅酸盐的空间时间分布变化、主要来源及它们与其它环境因子的关系等作一些探讨。     

Geomorphological processes and landforms of glacier forelands in the upper Aktru River basin(Gornyi Altai), Russia: evidence for rapid recent retreat and paraglacial adjustment

The glaciers in the Aktru River basin of Gornyi Altai, Russia currently represent some of the fastest receding glaciers in the world. Formation of the morainic complexes closest to the contemporary glaciers in the Aktru River basin took place during the 17^th-18^th centuries with recession commencing at the end of the 18 th century. Coupled with this glacial retreat, earth surface processes and vegetation succession are responding to shape the glacier forelands. This article presents the first geomorphological maps for the upper reaches of the Aktru River basin and focuses on the geomorphological landforms that occur in the rapidly changing glacier forelands. Geomorphological mapping is difficult in steep mountainous regions and, thus, mapping was completed using satellite imagery, field mapping and observations coupled with highresolution aerial photography obtained from Unmanned Aerial Vehicles(UAVs). Critical steps of the procedure used to process UAV imagery and difficulties encountered in this mountainous terrain are noted. The acquired spatial data enable the mapping and classification of small-scale transient geomorphological features such as talus, glacial and glaciofluvial landforms. Their dynamics provide insights into supraglacial and subglacial processes of the glaciers of the Aktru River basin and subsequent paraglacial adjustment. The presented highresolution spatial data, which can also be obtained at high temporal resolutions in the future, can act as a reference frame for geomorphologists and ecologists studying the temporal evolution of glacier forelands of the Aktru River basin during paraglacial adjustment and subsequent colonisation and stabilisation by biota.     

红层泥岩三轴膨胀力的试验研究

针对现有规范中红层泥岩膨胀力测试结果偏小问题,自主研制了膨胀性岩石三轴膨胀力测试装置。采用先放试样后加约束的方式克服了岩石与容器壁有释放变形空隙的局限性,解决了膨胀力测试结果偏小的问题。通过膨胀土和红层泥岩三轴膨胀力的测试研究,检验了三轴膨胀力测试装置的合理性和有效性,初步总结了红层泥岩三轴膨胀力的变化规律。研究结果表明:三轴膨胀力测试装置及其测试方法能够克服传统固结仪试验方法的局限性,具有较好的实用性,可以适用于膨胀土和膨胀岩三轴膨胀力的测试;红层泥岩三轴膨胀力多数是在MPa的量级,传统固结仪测试的膨胀力多数是kPa量级,更新了现有红层泥岩膨胀力较小的认识;通过对试验结果的分析和膨胀后试样的观察,发现红层泥岩的膨胀机制与膨胀土的膨胀机制是不同的;红层泥岩主要是新鲜岩石表层吸水膨胀、泥化崩解,泥化层剥蚀后,新鲜面再次吸水膨胀、泥化崩解,这是一个逐层循环膨胀的过程。     

北山构造带南部上地壳二维初至波层析成像

花海盆地—北山构造带南部位于青藏高原东北缘以北地区,是特提斯洋和古亚洲洋两大构造域的交接部位,自新元古代晚期以来经历了多期次、多阶段的板块裂解-俯冲-碰撞-拼合的演化历史,尤其是中生代以来的逆冲推覆和走滑作用,以及受新生代以来印度板块和欧亚板块碰撞的远程效应影响,导致青藏高原东北缘的向北扩展,形成了现今复杂的地质地貌结构。其地壳结构记录了多期构造作用的叠加,上地壳结构更是促进我们理解青藏高原东北缘向外的扩展机制及其对周缘块体的改造作用的天然记录本。本文利用2018年中国地质科学院在北山构造带南部完成的180 km深反射地震剖面的初至波(Pg震相)数据,通过层析成像反演方法,获得了花海盆地—北山构造带4 km深度范围内的上地壳P波速度结构。其主要特征为:花海盆地、总口子盆地和扎格高脑盆地均表现为较低的速度和较小的垂向速度梯度;研究区内的晚古生代花岗岩体具有明显的高速异常和较大的垂向速度梯度特征;左行走滑的阿尔金断裂带在花海盆地内表现为向北倾的高角度走滑性质,深度至少切穿花海盆地基底;北山南缘断裂带的推测隐伏区呈现速度等值线下凹的低速异常特征。同时,反演揭示的多处低速异常区指示了北山构造带南部的多处断层发育情况。     

Tonian–Ediacaran Tectonometamorphic History of the Sa’al Complex, Sinai (Egypt): Implications for the Tectonostratigraphic Framework of the Northern Arabian–Nubian Shield

The Sa''al Metamorphic Complex (SMC; southern Sinai) encompasses the oldest arc rocks in the Arabian–Nubian Shield, comprising two non-consanguineous metavolcanic successions (the Agramiya Group and the Post-Ra''ayan Formation) separated by the metasediments of the Ra''ayan Formation. It experienced three distinct deformational events (D1–D3) and two low-medium grade regional metamorphic events (M1–M2). The Agramiya Group and the Ra''ayan Formation experienced all tectonometamorphic events (D1–D3 and M1–M2), whereas the Post-Ra''ayan volcanic rocks were only affected by the D3 and M2 events. D1 is an extensional event and is connected to the late Rodinia break-up (~Tonian; 900–870 Ma). The M1 metamorphism variably affected the older Agramiya Group, the rhyolitic tuffs experiencing lower to upper greenschist facies conditions and the basic and intermediate volcanic rocks undergoing amphibolite facies metamorphism. The Ra''ayan Formation metasediments experienced upper greenschist to amphibolite facies metamorphism. The upper greenschist facies M2 affected the youngest Post-Ra''ayan volcanic rocks and other stratigraphic successions. The compressive D2 and D3 events were coeval with the accretion of dismembered terranes in the assembly of Gondwana. D2 can be linked to the Tonian–Cryogenian arc-arc assembly (~880–760 Ma; in Elat and Sinai), whereas D3 and the accompanying M2 is constrained to 622–600 Ma (Ediacaran).