K-H不稳定性在多电流片系统磁场重联中的效应

等离子体系统中存在两个或多个电流片时，电流片中发生的不稳定性可能会相互作用．行星际磁场北向时，背阳面碰层顶电流片与磁尾等离子体片之间可能发生相互作用，高纬边界层强烈的流场剪切可能促进磁场重联，产生磁层亚暴．本文运用二维可压缩磁流体模拟研究具有强流场剪切的多个电流片系统中磁场重联的演化．结果表明，Kelvin－Helmholtz不稳定性使多电流片系统的磁场重联过程明显加快；相邻电流片之间的距离越近，两者相互作用越强，重联增长率越大；在三电流片系统中，超Alfven速度强流场导致外侧两个电流片中出现强烈的磁场重联，并引发中心电流片的磁场重联．行星际磁场北向时，也可能发生磁层亚暴．     

克拉通盆地类型及成因机制综述

克拉通盆地是旨发育于稳定大陆块范围内的沉降区。其形成机制包括：拉伸减薄机制，热收缩沉投入为形机制。     

铭溪龙凤场铅锌混合矿选矿工艺的探讨

福建省大田县硫铁矿利用原有设备，部分进行技改配置生产铅锌混合矿；并采用铅锌混合优先浮选流程，经过一年多生产实践，混合矿质量均达到国家标准；但铅、锌回收率低。通过改造选矿工艺流程、增加精选槽数、稳定原矿和加强磨矿细度控制等试验表明，铅、锌回收率可稳定在９２％以上     

The Inner Magnetosphere: A Review

This paper addresses research achievements during roughly the period 1991–1993 pertaining to the inner magnetosphere including the radiation belts, plasmasphere, and ring current region. It also addresses issues concerning the magnetic fields, electrical currents, and particle precipitation properties that relate to this region of the solar-terrestrial system. Recent analysis and modeling of magnetospheric substorms and geomagnetic storms affecting the inner edge of the plasma sheet are discussed and the regions from the geostationary orbit inward toward the Earth are examined in light of new observational and theoretical tools.Presented at the 7th Scientific Assembly International Association of Geomagnetism and Aeronomy Buenos Aires, Argentina 8–20 August 1993.     

青藏高原有无大冰盖之争的现状

青藏高原有无大冰盖之争始于２０世纪初，至今已达８０余年。争论包括有无覆盖整个高原的大冰盖和有无局部小冰盖，以及它的形成年代，对便于气候变化的影响，可分为三个阶段：２０世纪初至４０年代，以少数西方探险家为主，论据不足，难于形讨论；从５０年代至７０年代，以中国学者为主的没有大冰盖论占绝对优势；８０年代至今中外学者众多、文献数百篇，是大争论的高潮，预示不久的将来，争论将逐渐平息，出现新的青藏高原科研热，     

山东东营凹陷东部深层浊积扇储层的微观特征及影响因素

东营凹陷东部深层浊积砂体以三角洲前缘的滑塌浊积砂体为主,储层岩性以长石细砂岩、岩屑细砂岩及粉砂岩为主,结构成熟度及成分成熟度均较低。储层微观特征研究表明,浊积砂体中主要发育剩余原生粒间孔、粘土矿物杂基内的微孔隙、粒间溶孔、粒内溶孔及微裂缝等储集空间类型;孔隙结构以低渗细喉型为主,为物性较差的中低孔、低渗型储层。通过对储层物性影响因素的研究得出,岩石组构、沉积微相、成岩作用和异常超压的形成与分布是影响本区浊积砂体储层物性的主要因素。其中成岩作用对浊积砂体物性的改造明显,压实和胶结作用是导致储层物性变差的主要原因;而溶蚀作用和成岩收缩作用则有利于储层孔渗性的改善。异常超压系统的存在、高的地温场及烃类的早期注入对该区浊积砂体储层物性起到了良好的保存和改善作用。     

黄土坡面片蚀过程稳定含沙量及其影响因素

黄土高原地区坡面土壤侵蚀具有明显的垂直分带性,溅蚀片蚀带是坡面侵蚀的最上方地带,研究片蚀过程含沙量变化有助于阐明坡面侵蚀规律。本文采用人工模拟降雨试验方法研究了黄土坡面片蚀稳定含沙量及其影响因素;试验处理包括2种质地的黄土(塿土和黑垆土),2个雨强(90和120 mm/h)和4个坡度(10°、15°、20°和25°)。结果表明：在不同质地黄土、降雨强度和坡度条件下,水流含沙量均呈现先减小后平稳的规律;稳定含沙量与土壤颗粒体积分形维数、降雨强度和坡度呈幂函数关系,稳定含沙量随土壤颗粒体积分形维数的增大而减小,随降雨强度和坡度的增大而增大,影响程度依次为土壤颗粒体积分形维数、降雨强度和坡度;所分析的水动力学指标中单位水流功率与稳定含沙量关系最密切,降雨强度对稳定含沙量的影响大于单位水流功率。     

“Megalosaurus cf. superbus” from southeastern Romania: The oldest known Cretaceous carcharodontosaurid (Dinosauria: Theropoda) and its implications for earliest Cretaceous Europe-Gondwana connections

Some of the best records of continental vertebrates from the Cretaceous of Europe come from Romania, particularly two well-known occurrences of dwarfed and morphologically aberrant dinosaurs and other taxa that lived on islands (the Cornet and Haţeg Island faunas). Substantially less is known about those vertebrates living in the more stable, cratonic regions of Romania (and Eastern Europe as a whole), particularly during the earliest Cretaceous. We describe one of the few early Early Cretaceous fossils that have ever been found from these regions, the tooth of a large theropod dinosaur from Southern Dobrogea, which was discovered over a century ago but whose age and identification have been controversial. We identify the specimen as coming from the Valanginian stage of the Early Cretaceous, an incredibly poorly sampled interval in global dinosaur evolution, and as belonging to Carcharodontosauridae, a clade of derived, large-bodied apex predators whose earliest Cretaceous history is poorly known. Quantitative analyses demonstrate that the Romanian tooth shows affinities with a derived carcharodontosaurid subgroup, the Carcharodontosaurinae, which until now has been known solely from Gondwana. Our results suggest that this subgroup of colossal predators did not evolve vicariantly as Laurasia split from Gondwana, but originated earlier, perhaps in Europe. The carcharodontosaurine diversification may have been tied to a north-to-south trans-Tethyan dispersal that took place sometime between the Valanginian and the Aptian, illustrating the importance of palaeogeographic ties between these two realms during the largely mysterious early–mid Early Cretaceous.