水牛蹄型深海集矿机履齿设计及牵引性能研究

作为深海采矿系统的重要组成部分,深海集矿机的技术研究和开发一直是许多国家的难题。为了提高深海集矿机在稀软沉积物上的牵引性能,基于水牛蹄的曲面结构特征和特殊几何结构,设计了一款仿水牛蹄蹄型履齿。以该款履齿的结构参数为研究对象,通过对朗肯被动土压力理论的优化,得到了仿水牛蹄蹄型履齿的牵引力解析解,建立了对应的履齿仿生参数对履齿牵引力的影响公式。结合正交试验方法进行了不同形式履齿在沉积物上运动的单、多履齿剪切试验,将仿水牛蹄蹄型履齿与直型履齿、仿水牛蹄轮廓履齿（另一种仿生履齿）进行对比试验,并通过模型车试验验证了该款履齿的可行性。结果表明：3种履齿中,仿水牛蹄蹄型履齿提供的最大牵引力最高。研究可为进一步优化仿水牛蹄蹄型履齿结构参数和提高深海稀软底质机械的牵引性能提供参考依据。     

建立特殊条件下导向钻孔轨迹跟踪和控制的数学模型

建立了在特殊场地条件下,利用雷达探测仪对非开挖钻孔轨迹跟踪和控制的数学模型。在工程实践中,结合计算机技术,利用这个数学模型提供的方法,可以更有效地对非开挖导向钻孔轨迹进行跟踪和控制。     

峪耳崖金矿的成矿时代裂变径迹研究

通过峪耳崖金矿含矿岩体中的锆石、磷灰石裂变径迹分析,揭示了自中生代燕山期以来峪耳崖地区经历了频繁、多期次的热液活动,且与峪耳崖金矿的形成密切相关.锆石、磷灰石的裂变径迹年龄显示,金矿成矿时代主要为115~200Ma,成矿下限为82 Ma.其中,115~190 Ma是主要的成矿时期.成矿流体作用遍及整个岩体;流体的运移受到构造制约,具有NE-SW延伸的趋势;成矿流体具深部来源以及在地表水的参与下成矿.峪耳崖金矿的形成,与当时整个中国东部的动力学背景有关.     

Rainfall–runoff responses on Arctic hillslopes underlain by continuous permafrost,North Slope,Alaska, USA

The Arctic hydrologic cycle is intensifying, as evidenced by increased rates of precipitation, evapotranspiration, and riverine discharge. However, the controls on water fluxes from terrestrial to aquatic systems in upland Arctic landscapes are poorly understood. Upland landscapes account for one third of the Arctic land surface and are often drained by zero‐order geomorphic flowpath features called water tracks. Previous work in the region attributed rapid runoff response at larger stream orders to water tracks, but models suggest water tracks are hydrologically disconnected from the surrounding hillslope. To better understand the role of water tracks in upland landscapes, we investigated the surface and subsurface hydrologic responses of 6 water tracks and their hillslope watersheds to natural patterns of rainfall, soil thaw, and drainage. Between storms, both water track discharge and the water table in the hillslope watersheds exhibited diel fluctuations that, when lagged by 5 hr, were temporally correlated with peak evapotranspiration rate. Water track soils remained saturated for more of the summer season than soils in their surrounding hillslope watersheds. When rainfall occurred, the subsurface response was nearly instantaneous, but the water tracks took significantly longer than the hillslopes to respond to rainfall, and longer than the responses previously observed in nearby larger order Arctic streams. There was also evidence for antecedent soil water storage conditions controlling the magnitude of runoff response. Based on these observations, we used a broken stick model to test the hypothesis that runoff production in response to individual storms was primarily controlled by rainfall amount and antecedent water storage conditions near the water track outlet. We found that the relative importance of the two factors varied by site, and that water tracks with similar watershed geometries and at similar landscape positions had similar rainfall–runoff model relationships. Thus, the response of terrestrial water fluxes in the upland Arctic to climate change depends on the non‐linear interactions between rainfall patterns and subsurface water storage capacity on hillslopes. Predicting these interactions across the landscape remains an important challenge.     

Low-temperature constraints on the Alpine thermal evolution of the Western Carpathian basement rock complexes

The Cretaceous to Palaeogene Alpine exhumation of previously buried Variscan basements is recorded in the southern portion of the Western Carpathians in the Gemeric and Veporic units. The Meso-Cenozoic collisional processes resulted in basement exhumation of the Tatric Unit from Palaeogene to Neogene times. According to zircon and apatite fission track data, the Gemeric Unit, an uppermost thick-skinned thrust sheet, cooled from depth levels of ∼10 up to 2.5 km (temperature interval of ∼250–60 °C) about 88–64 Ma ago, after the collapse of overlying Meliata-Turňa-Silica Mesozoic accretionary prism. The middle and lower thick-skinned thrust sheets, Veporic and Tatric units, cooled from the depths of ∼10 up to 2.5 km ∼110–40 Ma ago. The process was controlled by unroofing of footwall from beneath the Gemeric Unit. About 50–20 Ma ago, the internal zone of Tatric Unit gradually exhumed to depth of <2 km and some parts of the unit appeared at the surface level. However, the external zone of Tatric Unit was buried beneath the Eocene to Lower Miocene sedimentary successions and exhumed to the subsurface level at ∼21–8 Ma ago, as a result of oblique collision of the Western Carpathians with the European Platform.     

Possible sources of forecast errors generated by the global/regional assimilation and prediction system for landfalling tropical cyclones. Part I: Initial uncertainties

This paper investigates the possible sources of errors associated with tropical cyclone (TC) tracks forecasted using the Global/Regional Assimilation and Prediction System (GRAPES). The GRAPES forecasts were made for 16 landfalling TCs in the western North Pacific basin during the 2008 and 2009 seasons, with a forecast length of 72 hours, and using the default initial conditions (“initials”, hereafter), which are from the NCEP-FNL dataset, as well as ECMWF initials. The forecasts are compared with ECMWF forecasts. The results show that in most TCs, the GRAPES forecasts are improved when using the ECMWF initials compared with the default initials. Compared with the ECMWF initials, the default initials produce lower intensity TCs and a lower intensity subtropical high, but a higher intensity South Asia high and monsoon trough, as well as a higher temperature but lower specific humidity at the TC center. Replacement of the geopotential height and wind fields with the ECMWF initials in and around the TC center at the initial time was found to be the most efficient way to improve the forecasts. In addition, TCs that showed the greatest improvement in forecast accuracy usually had the largest initial uncertainties in TC intensity and were usually in the intensifying phase. The results demonstrate the importance of the initial intensity for TC track forecasts made using GRAPES, and indicate the model is better in describing the intensifying phase than the decaying phase of TCs. Finally, the limit of the improvement indicates that the model error associated with GRAPES forecasts may be the main cause of poor forecasts of landfalling TCs. Thus, further examinations of the model errors are required.     

地壳运动驱动力的探讨——核能与地球演化

本文综合核物理、天文和地质学的最新研究成果,推导出在45亿年前太阳系的全部原始类地行星及其某些卫星(包括地球及月球)上,发生过大规模的、持续的铀、钚链式核裂变,释出了巨大的热能,熔化了整个原始星球。新星球的物质发生了重力分异作用、形成了按密度划分的圈层结构。地球中心是内地核,在高压下压成了固态。铀、钚下沉到内地核顶部停留,继续发生链式核裂变,但改变不了内地核的固态性质。从此处产生的核裂变能,主要以热对流的形式外导。直到前45亿年以后,铀的链式核裂变停止了,只剩下钚的链式核裂变,生成的热能减少了,地球开始冷凝。当熔浆表面温度下降到700~800℃时,较轻的花岗岩质岩浆首先凝固成薄层。它很脆弱、经不起大风浪和潮汐力的冲击,破碎成小块,随着下面对流的玄武岩质熔浆汇集起来,形成大片飘浮物,后来就成为大陸;小片的便成为岛屿。温度逐渐下降,地幔冷凝成固体。温度下降至100℃以下,大气中的水蒸气冷凝成水,下落汇集在地表低凹处,便有了海洋和湖泊。所以海洋底主要分布着玄武岩。从内地核顶部不断产生的核能以"地幔柱"的形式穿过固体地幔,上升至地壳。受坚硬地壳的隔挡、便集中在地壳下构成软流层。当地壳岩石受热软化和可以流动之后,便开始向压力小的方向流动。又受日、月引力和地球自身自转力的作用,软流层的动能又有了增强。这种巨大的能量支配了地壳的升降、褶曲、断裂、变质、岩浆、火山和地震等活动。地球是天体之一,无时不受自然界各种作用力的影响,但支配它演化的主要作用力是核能。本文还简述了核能、核素与太阳系星体演化的关系。     

金川铜镍矿床中新生代抬升冷却过程：来自裂变径迹的证据

本文基于热年代学理论,利用锆石和磷灰石裂变径迹测年数据及对磷灰石热史的模拟,分析探讨金川铜镍矿床在中新生代的抬升冷却过程,认为金川超基性岩体自中生代以来一直处于持续的冷却抬升阶段,且在中侏罗世和晚白垩世早期经历了两期快速的抬升冷却事件,推断此事件与青藏高原后期活动时间相对应,证明金川岩体受到该事件的远程效应波及,致使该矿床遭受了一定的改造。     

Exhumation of the Mesozoic Guojialing Granodiorite: Implication for the Preservation of Gold Deposits in the Jiaobei Terrane,China

Preservation conditions are very important for mineral systems and a suitable exhumation process is critical for endogenetic deposits, especially for those deposits formed in orogenic settings, where deposits are inclined to erode away due to strong uplift. The G uojialing batholith, intruding into the L inglong granites and the J iaodong G roup right before regional gold mineralization, is one of the most important gold ore‐hosting M esozoic intrusions in the J iaobei terrane. Gold deposits and the intrusion together underwent similar tectonothermal evolutionary processes. Exhumation and denudation process of the G uojialing granodiorite was constrained by biotite geobarometry and apatite fission track (FT ) analysis. Biotite geobarometric data yields an emplacement depth of 3.0 km, while denudation since 110 M a was calculated from the FT data at about 2.7 km. FT inverse modeling revealed a rapid uplift since ca 100 Ma. Compared with the gold ore‐forming depth which is confined between 2.5 and 9.5 km by fluid inclusion studies, great gold potential in the depths is inferred in the J iaobei terrane. Our result is consistent, to some extent, with the hypothesis of a M esozoic paleoplateau in E ast C hina.     

CONDITIONAL NONLINEAR OPTIMAL PERTURBATIONS: APPLICATION IN TROPICAL CYCLONE FORECASTS

Considering the feature of tropical cyclones (TCs) that strong positive vorticity exists in the lower layers of troposphere, this study proposed to use vorticity at 850 hPa as cost function to find the conditional nonlinear optimal perturbation (CNOP), which was largely different from those previous studies using total energy of perturbed forecast variables. The CNOP was obtained by an ensemble-based approach. All of the sensitive areas determined by CNOP with vorticity at 850 hPa as cost function for the three cases were located over the TC core region and its vicinity. The impact of the CNOP-based adaptive observations on TC forecasts was evaluated with three cases via observational system simulation experiments (OSSEs). Results showed obvious improvements in TC intensity or track forecasts due to the CNOP-based adaptive observations, which were related to the main error source of the verification area, i.e., intensity error or location error.